on e+e- Higgs/EW/Top Factories, October 5-7, 2022, in Hamburg

5 Oct 2022, 08:00 → 7 Oct 2022, 23:20 Europe/Berlin

Auditorium (DESY Hamburg)

Christian Schwanenberger (CMS (CMS Fachgruppe TOP)), Gudrid Moortgat-Pick (University of Hamburg / DESY)

The 2022 meeting of the ECFA study on physics and experiments at e+e- Higgs/EW/Top Factories will take place in Hamburg at the campus of the DESY laboratory from October 5 to 7, 2022.

 

This meeting is intended to be an in-person meeting. 

The registration fee is 165 EUR until September 15th 2022, and 200 EUR thereafter.

Registration closes on September 26th 2022, 12:00.

Badges, participation confirmation, and payment receipts will be handed out at the registration.

ONLINE registration is possible now for free!

The central entry point of the ECFA study is accessible through this link.

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ECFA-Poster-Public_Event_Print.pdf

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Wednesday, 5 October

Registration

Convener: Christian Schwanenberger (CMS (CMS Fachgruppe TOP))

Plenary: Overview and Introductory Talks

Convener: Guy Wilkinson (University of Oxford (GB))

1 Opening & Introduction

Speakers: Beate Heinemann (DESY and University of Freiburg (Germany)), Christian Schwanenberger (CMS (CMS Fachgruppe TOP)), Karl Jakobs

ECFA22_intro.pdf

2 Physics case of an e+e- Higgs factory

Speaker: Matthew Mccullough (CERN)

PhysicsCase.pdf

video1393925932.mp4

3 News and input to ECFA study from circular and linear Higgs Factories

Speakers: Frank Simon (Max-Planck-Institute for Physics), Junping TIAN (The University of Tokyo)

InputfromStudies.pdf

video2393925932.mp4

10:30 Coffee break

Plenary: WG1: Physics Topics

Convener: Roberto Tenchini

4 Physics landscape at the start of a Higgs factory

Speaker: Philipp Roloff (CERN)

ecfa_workshop_2022_roloff.pdf

video3393925932.mp4

5 Precision theory requirements, developments & prospects for e+e-

Speaker: Ayres Freitas (University of Pittsburgh)

freitas.pdf

video4393925932.mp4

6 Interplay of indirect and direct searches at a Higgs factory

Speaker: Sven Heinemeyer (IFCA (CSIC, Santander))

sven.pdf

video5393925932.mp4

7 Open study questions

Speaker: Jenny List (FTX (FTX-SLB))

jlist_ecfaws_openquestions_221005.pdf

video6393925932.mp4

8 From Snowmass to the ECFA Higgs Factory Study

Speaker: Laura Reina (Florida State University)

ECFA22-2.pdf

video7393925932.mp4

12:50 Lunch

WG 1 - FLAV: Session 1

Flavour Physics

Convener: Stephane Monteil (Univertité Clermont Auvergne)

9 Implications of Flavour anomalies for Higgs/EW/top factories

Speakers: Nudzeim Selimovic (University of Zurich), Nudzeim Selimovic (University of Zurich)

Selimovic_ECFS_DESY.pdf

10 Prospects for rare B decays and flavour anomalies at Belle-II

Speakers: Alexander Glazov (DESY), Alexander Glazov (BELLE (BELLE II Experiment))

Prospects for rare decays and flavour anomalies at Belle II.pdf

11 Prospects for b → s nu nubar at Higgs/EW/top factories

Speaker: Aidan Wiederhold (University of Warwick)

b2snunu_ECFA_AidanWiederhold.pdf

12 Prospects of $B^+_c and B^+ \to \tau\nu$ decays at FCC-ee

The Z-pole operation at FCC-ee presents an unprecedented opportunity for heavy flavor physics, as the production of $5×10^{12}$ Z bosons will result in about $8×10^{11}$ b-quark pairs. Among all species of B hadrons produced at FCC-ee, the purely leptonic decays of the $B^+_c$ and $B^+$ mesons are clean experimental probes to measure the off-diagonal CKM elements $|V_cb|$ and $|V_ub|$, and are highly sensitive to test BSM models such as charged Higgs bosons and leptoquarks. A complete feasibility study of the $B_C^+$ to $\tau^+\nu_{\tau}$ measurement at FCC-ee is performed and its phenomenological impact on various new physics scenarios is explored. Recent developments have also been made in the measurement of the $B^+$ to $\tau^+\nu_{\tau}$ decay, demonstrating the feasibility of this measurement with a precision comparable to that of $B_c^+$. This set of work also showcases the FCC-ee analysis workflow fully based on common software tools from EDM4hep through to final analysis.

Speaker: Xunwu Zuo (Karlsruhe Institute of Technology)

Bc and Bu to tau nu at FCC-ee 2022.10.05.pdf

WG 1 - Searches: Session 1

Physics Potential - Searches
"Direct searches" working group (WG1-SRCH)
Roberto Franceschini, Rebeca Gonzalez Suarez, Aleksander Filip Żarnecki

Convener: Aleksander Filip Zarnecki (Faculty of Physics, University of Warsaw)

13 Long-Lived Particles at the FCC-ee

Many physics problems such as neutrino masses and the nature of dark matter predict particles with long lifetimes as an important possibility in the search for new phenomena. When produced at colliders, these long-lived particles (LLPs) have a distinct experimental signature: they can decay far from the collision point, or even completely pass through a detector before decaying. Since most of the trigger and reconstruction algorithms are optimized for short-lived particles, searches for LLPs can be challenging, usually requiring dedicated methods and sometimes also dedicated hardware to spot them. In the context of FCC-ee, crucial physics cases connected to LLPs will collect very high statistics in very clean experimental conditions. In this presentation, I will consider the high luminosity Z run and highlight three interesting physics cases that can produce LLPs at the FCC-ee: Heavy Neutral Leptons, Axion-Like Particles, and exotic Higgs boson decays.

Speaker: Juliette Alimena (CERN)

FCCLLP_ECFA_DESY_5Oct2022.pdf

14 Probing new physics with a LUXE-type experiment at future Higgs factories

The proposed LUXE (LASER Und XFEL Experiment) at DESY, Hamburg, using the 16.5 GeV electron beam from the European XFEL, aims to probe QED in the non-perturbative regime created in collisions between high-intensity laser pulses and high-energy electron or photon beams. This setup also provides a unique opportunity to probe physics beyond the Standard Model by leveraging the large photon flux generated at LUXE, probing axion-like-particles (ALPs) at a reach comparable to FASER2 and NA62. In this contribution we will explore the sensitivity of a LUXE-type experiment using the electron beam of future Higgs factories instead of the EU.XFEL one.

Speaker: Federico Meloni (ATLAS (ATLAS SM and Beyond))

LUXE_BSM_Higgs_factories.pdf

15 Benchmarking FIMP signatures at future Higgs factories

Feebly interacting massive particles (FIMPs) are characterised by very weak couplings and can be mediators to the dark sector or dark matter (DM) candidates themselves. In the latter case, the DM abundance is determined by the freeze-in mechanism (in contrast to freeze-out for WIMPs). Many FIMP scenarios are difficult to be constrained at the LHC and future e+e- Higgs factories seem to be a good place to look for them.

Typically, benchmark points (BPs) for studing collider sensitivity to Beyond the Standard Model (BSM) scenarios are selected in the model parameter space, providing predictions on the experimental signatures expected in a given experiment. We propose a different, more experiment-focused approach. A set of BPs is selected here to cover a range of experimental signatures, rather than a range of BSM model parameters.

The available space of physical FIMP parameters strongly depends on the particle type, coupling structure, and hence also the production scenario, which leads to particular signatures. Therefore, BPs are defined in the space of physical FIMP properties, directly related to the level of experimental sensitivity, for a given production channel and/or a signature. If FIMP is a mediator, this can be e.g. its mass, lifetime or branching ratios.

Speaker: Jan Klamka (University of Warsaw)

jklamka_ecfa_fimps.pdf

16 Stau searches and measurement prospects at future Higgs factories

The direct pair-production of the tau-lepton superpartner, stau, is one of the most interesting
channels to search for SUSY. First of all the stau is with high probability the lightest of
the scalar leptons. Secondly the signature of stau pair production signal events is one of
the most difficult ones, yielding the 'worst' and thus most general scenario for the searches.
The most model-independent limits on the stau mass come from LEP.
LHC exclusion reach extends to higher masses, but under strong model assumptions.
Future electron-positron colliders are ideally suited for stau searches: featuring increased
luminosity and centre-of-mass energy and improved technologies, with respect
to previous electron-positron colliders, and profiting from cleaner
environment, initial state being known, and trigger-less operation of the detectors, with respect
to hadron colliders.
The capability of a future electron-positron collider for determining stau exclusion/discovery limits in a model-independent way, together with an overview
of the current state-of-the-art and prospects on stau-properties measurements, are shown in this contribution.
The studies used the full detector simulation and reconstruction procedures of the
International Large Detector concept (ILD) at the ILC, all SM and machine induced backgrounds are included. The applicability to other projects will be discussed.

Speaker: Maria Teresa Nunez Pardo De Vera (FS-EC (Experimente Control))

StauSearches-ECFA22.pdf

17 SUSY at future colliders: Will e^+e^- colliders be relevant?

A study of the prospects for discovering or excluding SUSY at various
proposed future colliders is presented. The study is based on scan-
ning the relevant parameter space of (weak-scale) SUSY parameters.
In particular, I concentrate on the properties most relevant to evalu-
ate the experimental prospects: mass differences, lifetimes and decay-
modes. The observations are then confronted with estimated experi-
mental capabilities, including - importantly - the detail of simulation
these estimates are based upon. Conclusions on realistic prospects are
presented, and the answer to the question in the title is found to be "Yes".

Speaker: Carl Mikael Berggren (FLC (FTX Fachgruppe SLB))

berggren-ecfa-higgs-desy-oct22.pdf

WG 3: R&D: Session 1 - tracking and PID

Detector R&D

Convener: Giovanni Marchiori (APC Paris - CNRS/IN2P3 and Université de Paris)

18 Toward a vertex detector suited to a future Higgs factory based on CMOS pixel sensors

Small electrode CMOS Pixel Sensors (CPS) developed at IPHC-Strasbourg provide one the most promising approaches for vertexing and tracking devices suited to a Higgs Factory. Two different R&D CMOS processes are currently pursued based on 180 (mature) and 65 (recent) nm feature sizes respectively.

The 180 nm process is used to develop the MIMOSIS sensor for the MicroVertex Detector (MVD) of the CBM experiment at FAIR/GSI. It features in particular 5 µm and 5 µs spatial and time resolutions, while being adapted to hit densities near 100 MHz/cm² translating into 2 Bpbs output flow.
The first full scale prototype of MIMOSIS, composed of 500,000 pixels, was fabricated with two variants of in-pixel circuitry and
several different doping profile of their epitaxial layer.

In parallel, the 65 nm technology of TPSCo with pixel pitch of 15 and 25 µm respectively is being explored to achieve smaller pixels adapted to in-pixel low power and signal processing functionalities.

Beam test results for both 180 and 65 nm will be presented and complemented by prominent aspects of the next step of the prototyping, in particular multi-reticle sensors exploiting the stitching technique as well as bending technique in partnership with the ALICE-ITS3 groups.

Speaker: Dr Ziad EL BITAR

Towards a vertex detector suited to a future Higgs factory based on CMOS pixel sensors_v1.pdf

19 Silicon Detector R&D for IDEA

Current R&D on silicon detectors considered for the IDEA concept is described. In particular recent results from the ARCADIA project and the ATLASpix3 sensors. Additional work on LGADs and vertex detector mechanics will also be described.

Speaker: Coralie Neubuser (TIFPA-INFN, Trento)

20221005_ecfa_IDEASi_v3.pdf

20 High spatial resolution pad and pixelated TPC technology R&D for the e+e- collider

Time Projection Chamber (TPC) could be used as a central high spatial resolution tracking detector at future electron-positron colliders such as ILC, CEPC or FCC-ee. A large worldwide community of physicists is working to realize EWK precision physics program at the future e+e- Higgs Factory. In the ILD detector concept, a large volume TPC is embedded in a magnetic field of B=3.5T, the requirements for the TPC are a continuous tracking with very high efficiency and a single hit resolution of better than 100µm in the transverse direction. The TPC performance of the spatial resolution and dE/dx have been measured using three different readout modules (GEMs, Resistive Micromegas and GridPix) in a magnetic field of B=1.0T at DESY. In the conventional readout the pad size is ~1mmx6mm and in the pixelated readout it is about 55μmx55μm. During Tera-Z operation at the high luminosity, the pixelated readout can reach better spatial resolutions with higher detection efficiency. To improve the particle identification using dE/dx and dN/dx, the cluster counting method shows significant potential, but a high readout granularity is needed. In this talk, we will present the updated results and plans of TPC technology potential extending to other e+e- colliders.

Speaker: Dr Huirong Qi (Institute of High Energy Physics, CAS)

ECFA_LCTPC_IHEP__Huirong_20220930.pdf

21 R&D on a drift chamber with cluster counting and on micro-rWell chambers for the IDEA detector

The drift chamber proposed for the IDEA detector concept and the associated R&D in progress will be described. In particular current work on the cluster counting technique will be reported, including results from recent test beams at CERN.

The muon system for the IDEA detector is discussed. In particular current and future R&D on chambers based on the micro-rWell techique are described, including recent test beam results.

Speaker: Nicola De Filippis (Politecnico and INFN Bari)

DeFilippis_IDEA_DCH_mWELL.pdf

22 Prospects of time-of-flight particle identification at the future Higgs factories

One of the important aspects of the future Higgs factory is particle identification, which is important for precision measurements and plays a crucial role for flavour physics. Recent technology developments of Si sensors, e.g. LGADs, enable time resolutions below 50 ps. This allows to use measurement of the time-of-flight as a tool for particle identification of $\pi^{\pm}$, $K^{\pm}$ and $p$ up to roughly 5 GeV momentum. Time-of-flight particle identification serves as a great complementary tool for dE/dx in gaseous detectors and the only available particle identification tool in fully Si detector designs. In this talk we will discuss the latest developments of the time-of-flight particle identification tool, its physics applications at the future Higgs factory and the potential impact on the detector design using International Large Detector (ILD) at the International Linear Collider (ILC) as an example case.

Speaker: Bohdan Dudar (FTX (FTX Fachgruppe SLB))

ECFA22.pdf

WG1: joined HTE & GLOB session

Convener: Jorge de Blas Mateo (University of Granada)

23 Prospects for the measurement of top-quark couplings

In this work the prospects for measurements of the top-quark couplings at future colliders are presented. Projections are presented for the high luminosity phase of the Large Hadron Collider and a future Higgs/electroweak/top factory electron-positron collider. Results are presented for the expected bounds on Wilson coefficients of the relevant SMEFT operators from a global fit to the top-quark physics sector.

Speaker: Dr Victor Miralles (INFN Roma1)

VMiralles_DESY_top-quark.pdf

24 Prospects for constraining or discovering top FCNC at the LHC and at e+e- colliders

Speaker: Gauthier Durieux (CERN)

durieux-ecfa-5oct2022.pdf

25 Differential top cross section and ttV measurements at the LHC and HL-LHC prospects

Speaker: Andreas Werner Jung

26 CP-sensitive top-quark measurements

Speaker: Marcel Vos (IFIC (UVEG/CSIC) Valencia)

CPViolationTopSectorFutureEE.pdf

27 Probing the CP properties of Higgs bosons via transverse polarization at $e^+ e^-$ collider

In the CP-violating 2HDM, the CP-violating Higgs to fermions couplings can make an additional loop contribution on the Higgs to gauge bosons couplings. In order to address this aspect, we consider a generic model which has the effective CP-violation structure of the Higgs to gauge bosons couplings. We explore the effect of CP-violation term via the process $e^+ e^- \rightarrow HZ, Z\rightarrow \mu^+ \mu^-$, where the angular distribution of muon pair can be sensitive to the CP-violation structure. In particular, the transverse polarization of the initial beams can be applied to single out the effect of CP-violating term compared to the unpolarized or longitudinally polarized beams. We discuss the set-up and the results for the differential cross section and the asymmetries with respect to the CP-odd observables with transverse polarization, at the future $e^+ e^-$ collider with center-of-mass energy 250 GeV.

Speaker: Cheng Li (FTX (FTX Fachgruppe SLB))

chengli_ecfa.pdf

15:30 Coffee break

15:30 Coffee break

15:30 Coffee break

15:40 Coffee break

WG 1 - Global: Session 1

Physics potential: global interpretations

Convener: Alexander Grohsjean (CMS (CMS Fachgruppe TOP))

28 (g-2)_mu and SUSY: ILC and CLIC Physics Opportunities

The electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for a variety of experimental data. The lightest SUSY particle (LSP), the lightest neutralino, is a perfect Dark Matter (DM) candidate. The EW spectrum can easily explain the discrepancy between the experimental value of the anomalous magnetic moment of the muon, $(g-2)_\mu$, and its SM prediction. Taking these constraints as well as LHC searches into account, we derive upper limits on the lighter part of the MSSM spectrum of $\le$ 650 GeV. We discuss how this parameter space can be tested at the ILC and CLIC, as well as the complementarity with DM direct detection experiments.

Speaker: Sven Heinemeyer (IFCA (CSIC, Santander))

sven-SUSY.pdf

29 Fixing the SMEFT Lagrangian with data from e+e- Higgs factories

Speaker: Michael E. Peskin

SMEFTate+e-colliders.pdf

30 Overview of the Snowmass SMEFT fit results

Speaker: Victor Miralles (IFIC-UV)

VMiralles_DESY_SMEFT_Fit_Results.pdf

31 Mapping EFT on concrete models

Speaker: Ricardo Cepedello (University of Würzburg)

Cepedello_ECFA_DESY_2022.pdf

32 Global fits in concrete models with Gambit

Speaker: Tomas Gonzalo

TGonzalo_ECFA_Talk.pdf

WG1: joined HTE & SRCH session

Conveners: Karsten Koeneke (Uni Freiburg), Roberto Franceschini (CERN)

33 Dark sector in Two Higgs Doublet extensions with a Complex Scalar Singlet [zoom]

Extension of the Two Higgs Doublet model augmented with a complex scalar singlet (2HDMS) is a well motivated candidate for Beyond Standard Model (BSM) Physics. In this talk, we focus on the dark matter (DM) phenomenology of 2HDMS and investigate cases where the singlet doesnot obtain a vacuum expectation value (vev) and act as the DM candidate. We also consider the case where the singlet develops a vacuum expectation value (vev) and the pseudoscalar component is the DM candidate. We perform a parameter scan to study the impact of relic density and direct detection scenarios on the model parameter space for both cases. Some representative benchmarks are chosen for the former case and potential signals at future e+e- colliders are presented.

Speaker: Juhi Dutta (UNI/TH (Uni Hamburg, Institut fuer Theoretische Physik))

JuhiDutta_ECFA 1.pdf

34 A Tale of Two Portals: Testing Light, Hidden New Physics at Future e+e− Colliders

We investigate the prospects for producing new, light, hidden states at a future $e^+e^-$ collider in a Higgsed dark $U(1)_D$ model, (the Double Dark Portal model). The simultaneous presence of both vector and scalar portal couplings immediately modifies the SM $e^+e^-\to Zh$ process at leading order in each coupling. After accounting for current constraints, we demonstrate that a future Higgs factory will have leading sensitivity to the two portal couplings in production, decay, and radiative return processes. Besides exotic Higgs decays, we highlight the importance of direct dark vector and scalar production tagged from the recoil mass method.

Speaker: Felix Yu (JGU Mainz)

ECFA_Tale_Of_Two_Portals_FY.pdf

35 Triple Higgs couplings of the 2HDM at the ILC and CLIC

We analyze the parameter space allowed in the Two Higgs Doublet Model (2HDM) with respect to all current experimental and theoretical constraints. We show the allowed ranges for the various triple Higgs couplings, depending on the Yukawa type of the model. We discuss the accessibility of BSM triple Higgs couplings at the ILC and CLIC.

Speaker: Francisco Arco Garcia (Instituto de Física Teórica (IFT-UAM))

Arco-ECFA.pdf

36 New BSM Higgs bosons: e+e- collider physics potential

We discuss the mounting evidence for a 95 GeV Higgs boson, as well as interesting excesses in the searches for heavier Higgs bosons at $\sim$ 400 GeV. We show how these excesses can described in the Two Higgs Doublet Model plus real singlet (N2HDM), or in the Next-to-Minimal Supersymmetric Standard Model (NMSSM). We discuss the physics potential of future $e^+e^-$ colliders to analyze these scenarios.

Speaker: Sven Heinemeyer (IFCA (CSIC, Santander))

sven-Higgs.pdf

37 Searches for light scalars at LHC and interpretation of the findings

LHC has discovered a light boson h(125), residual of EWSB in the SM and no heavy particle. More generally, one can assume that scalars due to BSM symmetry breaking mechanisms are likely to be the lightest particles produced at LHC and the only new particles reachable at future lepton colliders. From a systematic survey of LHC data, I conclude that there are 4 likely candidates, all reaching a global evidence above 4 s.d. Confronted to the most popular models, it turns out that models with triplets, as initially proposed by Georgi and Machacek (GM) in 1985, are able to interpret these candidates. Its major prediction, based on unitarity requirements, is an upper bound, 700 GeV, on the masses of all these scalars, therefore accessible to LHC and at future e+e- TeV Linear Colliders (LC) proposed by the community of particle physics. This model needs to be extended in several ways, which are naturally embedded within a SUSY version of GM, SGM, which offers a promising scenario for a global and calculable theory describing particle physics and cosmology. Quantitative predictions are given for e+e- cross sections of the relevant processes. Promising searches for HL-LHC are briefly described.

Speaker: Francois Richard (IJCLab Orsay)

Talk-ILCX21-DESY.pdf

Talk-ILCX21-DESY.pptx

WG 1 - Precision: Session 1

Physics potential: precision

Convener: Adrian Irles (IFIC CSIC/UV)

38 Electroweak precision (Z/W) measurements at future e+e- colliders

Speaker: Alain Blondel (Universite de Geneve (CH) and CNRS (France))

Blondel-FCC-EW-HiEWTop-2022-10-05.pptx

39 Top quark threshold and QCD measurements at future e+e- colliders

Speaker: Frank Simon (Max-Planck-Institute for Physics)

TopThresholdandQCD.pdf

40 Theory precision calculations for future e+e- colliders: status and prospects

Speaker: Juergen Reuter (T (Phenomenology))

2022_ECFAHiggs_JRR_Prec.pdf

WG 2: Physics Analysis Methods: Session 1

Physics Analysis Methods

Conveners: Alan Price (University of Siegen), Dirk Zerwas (IJCLab and DMLab), Fulvio Piccinini, Patrizia Azzi (INFN)

41 Luminosity Spectra for lepton colliders

Speaker: Thorsten Ohl (Universität Würzburg)

circe2-presentation.pdf

42 QCD for Lepton Colliders

Speaker: Daniel Reichelt (Durham University, IPPP)

ECFA_QCDatEE_DReichelt.pdf

43 QED Status and Benchmarking Event Generators for Lepton Colliders

Speaker: Alan Price (University of Siegen)

talk_aprice.pdf

44 Progress in DELPHES

Speaker: Michele Selvaggi (CERN)

delphes_ecfa2022.pdf

45 Generative Models for Fast Simulation of Electromagnetic and Hadronic Showers in Highly Granular Calorimeters

Simulation in High Energy Phyiscs (HEP) places a heavy burden on the available computing resources and is expected to become a major bottleneck for the upcoming high luminosity phase of the LHC and for future Higgs factories, motivating a concerted effort to develop computationally efficient solutions. Methods based on generative machine learning methods hold promise to alleviate the computational strain produced by simulation, while providing the physical accuracy required of a surrogate simulator.

In this contribution, we provide an overview of a growing body of work focused on simulating showers in highly granular calorimeters, which is making significant steps towards realistic fast simulation tools based on deep generative models. Progress on the simulation of both electromagnetic and hadronic showers will be reported, with a focus on the high degree of physical fidelity and computational performance achieved. Additional steps taken to address the challenges faced when broadening the scope of these simulators, such as those posed by multi-parameter conditioning, will also be discussed.

Speaker: Engin Eren (FLC (FTX Fachgruppe SFT))

eren_ecfaHiggs.pdf

Conference Dinner

Thursday, 6 October

Plenary: WG2: Generators, Simulation & Reconstruction Topics

Convener: Chiara Meroni

46 The Software Eco-System

Speaker: Thomas Madlener (FLC (FTX Fachgruppe SFT))

sw_ecosystem_ecfa2022_madlener.pdf

video1119383162.mp4

47 Generators: Back to the Future

Speaker: Andrzej Konrad Siodmok (Jagiellonian University)

BackToTheFutureECFA_ee-5.pdf

video2119383162.mp4

48 Simulation: Going Fast, Full and Fully Fast

Speaker: Andre Sailer (CERN)

221006_sailer_simulation.pdf

video3119383162.mp4

49 Reconstruction: Imaging the Events

Speaker: Erica Brondolin (CERN)

20221005_RecoInHiggsFactories_ECFA_final.pdf

video4119383162.mp4

Workshop Photo

Convener: Christian Schwanenberger (CMS (CMS Fachgruppe TOP))

10:45 Coffee break

Plenary: WG3: Detector Topics

Convener: Jean-Claude Brient

50 ECFA Detector Roadmap and Implementation Plan

Speaker: Felix Sefkow (DESY)

DetRoadmap-FS-20221006.pdf

video1274854211.mp4

51 Tracking and Vertexing for Higgs Factories

Speaker: Dominik Dannheim (CERN)

Tracking-and-Vertexing-for-Higgs-Factories-ECFA-WS-6-Oct-2022.pdf

video2274854211.mp4

52 Calorimetry and Particle ID for Higgs Factories

Speaker: Katja Krueger (DESY (FTX Fachgruppe DTA))

ECFA_HiggsEWtop_caloPID_20221006_v1.1.pdf

video3274854211.mp4

12:45 Lunch

WG 1 - FLAV: Session 2

Flavour Physics

Convener: David Marzocca (INFN Trieste)

53 Lattice QCD progresses and bottlenecks at the dawn of Higgs/EW factory

Speaker: Andreas Juettner (CERN/University of Southampton)

ECFA e+e- Juettner.pdf

54 Heavy Flavours, CKM, and rare decays measurements: some detector requirements

Speaker: Stephane Monteil (Univertité Clermont Auvergne)

ECFA#1_Flavours_monteil_20221006.pdf

55 Simulation of selected top-quark processes at FCC-ee and their interpretation in terms of effective field theories

Experiments at future circular colliders such as the FCC-ee are expected to improve electroweak and top-quark physics in an unrivaled way. This talk gives an overview on the sensitivity of selected top-quark pair production observables taking into account dimension-six extensions of the Standard Model and following an optimal-observable analysis. Relevant observables and their parameterizations as function of the dimension-six operator strength are given.

Carrying out these generator-level studies to reconstructed objects in the FCC-ee environment requires for an adequate event selection and definition of the relevant objects of the process under study. Here, the semileptonic and dileptonic decay channels of $t\bar{t}$ production are taken into account and recently improved methods for missing momentum component entanglement at lepton colliders are presented on reconstructed events.

Speaker: Lars Roehrig

ECFA_LRoehrig.pdf

56 From strange to top: activities of the Top/QCD/HF physics group of ILD

The process ee->qq with qq=ss,cc,bb,tt plays a central role in the physics programs of high energy electron-positron colliders operating from the O(100GeV) to O(1TeV) center of mass energies. Furthermore, polarised beams as available at the International Linear Collider (ILC) are an essential input for the complete measurement of the helicity amplitudes that govern the production cross section. Quarks, specially the heaviers, are likely messengers to new physics and at the same time they are ideal benchmark processes for detector optimisation. All four processes call for superb primary and secondary vertex measurements, a high tracking efficiency to correctly measure the vertex charge and excellent hadron identification capabilities. Strange, charm and bottom production are already available below the ttbar threshold.
This contribution will cover the most relevant and latest activities of the ILD concept group on physics studies related to heavy quarks, using detailed simulation and realistic analysis tools
to determine the full potential of ILC on this area. Some of the topics to be discussed will be the top-quark mass measurements, top and less heavy quarks electroweak couplings or BSM searches at ILC with the ILD.

Speaker: Adrian Irles (IFIC CSIC/UV)

ECFAHF2022_Irles_v2.pdf

WG 1 - Higgs/ Top/ EW: Session 1

Physics Potential - Higgs, top, and electroweak

Convener: Karsten Koeneke (Uni Freiburg)

57 Introduction

Speakers: Chris Hays (Oxford University), Fabio Maltoni (Université catholique de Louvain), Karsten Koeneke (Uni Freiburg)

2022Oct05 ECFA HiggsFactory Workshop Hamburg - HTE Introduction.pdf

58 Measurements to improve hadronization models

Speaker: Prof. Frank Krauss (Durham University)

ECFA22_Hadronization.pdf

59 Physics potential for $\mathrm{\sigma x BR(H \rightarrow ZZ^*)}$ measurement at CLIC

CLIC is a linear e$^+$e$^-$ collider designed to reach center-of-mass energies ranging from 350 GeV, 1.4 TeV up to 3 TeV. Individual measurements of Higgs couplings in various Higgs production and decay channels are subject of a global fit in order to achieve the ultimate statistical precision of the cumulative CLIC data. In this talk we discuss the $\mathrm{\sigma x BR(H \rightarrow ZZ^*)} $ measurement at all CLIC energy stages, in a full simulation of detector and experimental conditions.

Speaker: Ms Natasa Vukasinovic (VINCA Institute of Nuclear Sciences, University of Belgrade)

H_ZZ_ECFA2022_CLIC_final.pdf

60 Diboson measurements, including anomalous couplings, at future e+e- colliders

Speaker: Jiayin Gu

wwoo4.pdf

61 Prospects for aTGC / EFT constraints at the LHC and at e+e- colliders

Speaker: Rafiqul Rahaman

Rafiqul-Rahaman-ecfa-desy.pdf

WG 2: Physics Analysis Methods: Session 2

Physics Analysis Methods

Conveners: Dirk Zerwas (IJCLab and DMLab), Fulvio Piccinini, Patrizia Azzi (INFN)

62 Reconstruction with KEY4HEP

Speaker: Juraj Smiesko

Presentation link

Reconstruction with Key4hep [Smiesko].pdf

63 High level reconstruction for Higgs factories

LCFIPlus, a combined package for vertex finding, jet clustering and flavor tagging is a software package used as a standard tool for the jet analysis of linear colliders since 2012. As the author is one of the original developers, the overview of the software and performance on the ILD is presented. The recent development in our group, yet not finished, to improve the performance of vertex finding, flavor tagging and particle flow for Higgs factories using DNN techniques are also reviewed.

Speaker: Taikan Suehara (Kyushu University)

221003-ecfahfws-highreco-suehara.pdf

64 PID with Cluster Counting

Speaker: Nicola De Filippis (Politecnico and INFN Bari)

DeFilippis_IDEA_PID_DCH.pdf

65 Identification of charged leptons in jets at future Higgs factories.

An important goal at future Higgs factories are precise measurements of the 125
GeV Higgs boson properties. As the Higgs boson predominantly decays
to $b\bar{b}$, the precise reconstruction of heavy flavor jets is crucial. A source
of uncertainty for these jets is missing momentum from semi-leptonic
decays $b\to\ell\nu X$. Recent work has shown the possibility of correcting
this missing neutrino momentum. For this, the charged lepton from
the decay needs to be successfully reconstructed and identified. While
particle flow detector concepts with their high granularity offer ideal
conditions to identify leptons inside jets, the excellent hardware needs
to be matched with corresponding reconstruction algorithms. In this
work, we use the detailed simulation of the ILD detector concept to
investigate how to exploit the information provided by a particle flow
detector to identify single electrons and muons in a dense environment
and how this improves the reconstruction of $H\to b\bar{b}$ decays.

Speaker: Leonhard Reichenbach (FTX (Technol. zukuenft. Teilchenph. Experim.))

ecfa-ws-reichenbach_2022_10_06.pdf

66 A Particle Identification Framework for Future Higgs Factories

The particle physics community has concluded that the next collider should be a Higgs factory with the ability to also produce a large number of W and Z bosons. In the ongoing discussions it has become increasingly clear that particle identification including charged hadron ID is a key feature that enables a number of analyses and improves many. A number of different PID systems - from the simple muon ID to gaseous dE/dx and dN/dx to calorimeter shower shapes and time of flight (and more) - are being envisioned for the proposed FHF detector concepts. It is desirable to assess their impact and the effect of combining them in a common tool to enable fair comparisons.

This talk presents a new modular approach to a generic PID framework for the different possible FHFs. It discusses implementation questions, performance measures and possible physics applications, exampling the International Large Detector (ILD) concept for the International Linear Collider (ILC).

Speaker: Ulrich Einhaus (FTX (Fachgruppe SLB))

2022_10_06_ECFA_WS.pdf

67 ErrorFlow: Jet Error Estimation for Kinematic Fitting in Particle Flow Detectors at Future Higgs Factories

Constrained fits improve the kinematic reconstruction of the final state in many Higgs, top and electroweak physics studies. This is a powerful tool, particularly at $e^{+}e^{-} $ colliders where the initial state four-momentum is known and can be employed to constrain the final state. An accurate estimate of the measurement uncertainties, particularly for composed objects like jets, is a crucial ingredient to kinematic fitting. Detectors optimized for particle-flow reconstruction provide a detailed estimation of the covariance matrices for individual particle flow objects in addition to an excellent four-momentum measurement. These can be combined to derive an estimate of the individual covariance matrix of the four-momentum of each jet by an algorithm called ErrorFlow. This contribution will present the improvements by the application of ErrorFlow in the $ZH$ versus $ZZ$ separation at $\sqrt{s}$=250 GeV, using the full simulation of the International Large Detector as an example of a highly-granular ParticleFlow optimized detector concept.

Speaker: Yasser Radkhorrami (FLC (FTX Fachgruppe SLB))

Yasser_Radkhorrami_ECFA_Higgs_WS_2022.pdf

15:30 Coffee break

15:30 Coffee break

15:40 Coffee break

WG 1 - Precision: Session 2

Physics potential: precision

Convener: Paolo Azzurri

68 Enabling precision electroweak measurements at high energy e+e-colliders with detector-based center-of-mass energy measurements

One of the challenges for future e+e- colliders is adequate control of
the center-of-mass energy, and the associated luminosity spectrum.
For linear colliders at all energies and for circular colliders
at center-of-mass energies above 200 GeV one can not rely on resonant
beam depolarization and must use collision data driven methods.
The contribution will focus on progress related to this issue based on
reconstruction of di-muon events that leverages a precise tracker momentum
scale calibration, and will discuss a few of the electroweak measurements
such as the W and Z masses and widths and the left-right asymmetry that are
made feasible particularly at a linear collider. The talk will also address
associated detector performance requirements.

Speaker: Graham Wilson (University of Kansas)

ECFAHamburg_V3.pdf

69 Three-loop massive form factors

In this talk three-loop QCD corrections to heavy quark form factors
are presented. They constitute the virtual corrections for various
processes as, e.g., top quark production in $e^+ e^-$ annihilation or
Higgs decay into heavy quarks. A semi-numerical method is discussed,
which is based on expansions around singular and regular kinematical
points. They are matched at intermediate values of the squared
partonic center-of-mass energy $s$ which allows to cover the whole
kinematic range. The method permits a systematic increase of the
precision by varying the expansion depth and the choice of the
intermediate matching points. Results are presented for various
choices of external currents.

Speaker: Matthias Steinhauser (KIT)

steinhauser.pdf

70 Event shapes and jet substructure at past and future lepton colliders

Jet substructure is an important tool in analyses at the currently running LHC
experiments. These observables, and likewise related event shapes, can be
expected to play an important role at future colliders, both in the study of QCD
effects as well as in the tagging of jet properties to identify signal enhanced
phase space regions in various analyses. In this talk I will present examples
for such applications, using resummed results for event shapes and jet
substructure at $e^+e^-$ colliders. These predictions are obtained using the
Sherpa event generator framework, both for Monte Carlo simulations as well as in
conjunction with analytic resummation in the CAESAR framework.

Speaker: Daniel Reichelt (Durham University, IPPP)

ECFA_EventShapes_DReichelt.pdf

71 Parton showers from old to new paradigms

I will present recent developments on accurate (QCD) parton showers at the NLL level and I will outline new approaches based on amplitude level evolution which have led to improved algorithms, links to hadronization models, and touch further aspects such as electroweak evolution.

Speaker: Simon Platzer (University of Graz)

slides-talk-compressed.pdf

72 Photo-production at NLO QCD

Photo-production is a non-negligible contribution to cross-sections at lepton—proton and lepton—lepton colliders, amounting to in fact over half of the QCD cross section. In this talk I will discuss the framework in the Sherpa event generator that allows the calculations of both unresolved and resolved photon contributions. I will show comparisons of simulated events at MC@NLO accuracy with data from the LEP and HERA experiments. I will present results for different sensitive observables for a future e+e- collider, motivating further investigations of the hadronic structure of the photon. Finally, I will discuss how these simulations will help in understanding the QCD background as well as the underlying event and allow for more tests of QCD at future lepton colliders.

Speaker: Mr Peter Meinzinger (IPPP, Durham Uni)

talk-photoprod.pdf

WG 1 - Searches

Physics Potential - Searches
"Direct searches" working group (WG1-SRCH)
Roberto Franceschini, Rebeca Gonzalez Suarez, Aleksander Filip Żarnecki

Convener: Roberto Franceschini (CERN)

73 Higgs Naturalness at a HTE factory

The nature of electroweak symmetry breaking and the Higgs bosons are likely paths to physics beyond the standard model. Neutral naturalness, symmetry based constructions for addressing the electroweak hierarchy problem/puzzle, have garnered increasing interest as LHC bounds on new colored states have increased. These models often predict new electroweak states along with a rich Higgs sector. I provide an overview of ways an HTE factory can explore these scenarios including the direct production of new states and exotic Higgs decays.

Speaker: Chris Verhaaren (Brigham Young University)

HiggsNatECFAOct2022.pdf

74 Heavy Neutrinos at Future Linear e+e- Colliders

Neutrinos are probably the most mysterious particles of the Standard Model. The mass hierarchy, oscillations and the nature of their antiparticles are currently being studied in many experiments. Moreover, in models of New Physics, baryon asymmetry or dark matter density are explained by introducing new species of neutrinos. Among others, heavy neutrinos of the Dirac or Majorana nature were proposed to solve problems persistent in the Standard Model. Such neutrinos could be produced at future e+e- colliders.

We studied the possibility of observing decays of heavy neutrinos in qql final state at future e+e- machines for a wide range of collision energy, starting from 250 GeV up to 3 TeV. The analysis is based on the WHIZARD event generation and fast detector simulation with DELPHES. Dirac and Majorana neutrinos with masses from 100 GeV to 3.2 TeV are considered. Estimated limits on the production cross section and on the neutrino-lepton coupling are compared with the current limits coming from the LHC running at 13 TeV and future hadron colliders. The obtained results are stricter than other estimates published so far. The potential of future colliders to discriminate between Dirac and Majorana nature of the new heavy lepton is also discussed.

Speaker: Krzysztof Mekala (University of Warsaw)

Mekala_ECFA.pdf

75 Light mediator searches with mono-photon signature

With mono-photon signature, high energy e$^+$e$^-$ colliders offer unique possibility to look for processes with fully invisible final state, pair-production of dark matter particles in particular. Most studies in the past focused on scenarios assuming heavy mediator exchange. However, scenarios with light mediator exchange are still not excluded by existing experimental data, if the mediator coupling to Standard Model particles is very small. Results on the expected sensitivity of the 500 GeV ILC and the 3 TeV CLIC to scenarios with both heavy and light mediator exchange were presented recently based on a novel approach, where the experimental sensitivity is defined in terms of the mediator mass, width and
coupling to the electrons.Included in this contributions are new results on the sensitivity of the 250 GeV Higgs Factory to dark matter pair-production via light mediator exchange.

Speaker: Aleksander Filip Zarnecki (Faculty of Physics, University of Warsaw)

zarnecki_ecfa2022_v2.pdf

76 Dark Photon Searches at Future $e^{+}e^{-}$ Colliders

In theories where dark matter is explained by the existence of a 'dark sector', interacting with the visible sector of the standard model via gravitation, the photon of the dark sector, the dark photon $(A_{D})$, might be the only visible manifestation of the dark sector due to kinetic mixing with the (ordinary) photon. The strength of the mixing is given by a mixing parameter $(\epsilon)$. This is the same parameter governing both the production cross-section and the decay of the $A_{D}$ back to SM particles. Detectors at future e+e- colliders will have excellent momentum resolution and equally excellent track-finding efficiency. These are the features needed to probe for the expected signal of a $A_{D}$, namely a quite small, and quite narrow resonance: If $(\epsilon)$ is large enough to yield a detectable signal, its decay width will be smaller than the detector resolution, but so large that the decay back to SM particles is prompt. This study investigates the dependency of the limit on the mixing parameter and the mass of the $A_{D}$ using the $A_{D}\rightarrow\mu^{+}\mu^{-}$ decay mode in the presence of standard model background, using fully simulated signal and background events in the ILD detector at the ILC Higgs factory.

Speaker: Sepideh Hosseini Senvan (FTX (FTX Fachgruppe SLB))

Sepideh_Hosseini_ECFAOctober2022.pdf

77 Probing new U(1) gauge symmetries via exotic Z→Z′γ decays

New U(1) gauge theories involving Standard Model (SM) fermions typically require additional electroweak fermions for anomaly cancellation. We study the non-decoupling properties of these new fermions, called anomalons, in the Z−Z′−γ vertex function, reviewing the connection between the full model and the effective Wess-Zumino operator. We calculate the exotic Z→Z′γ decay width in U(1)B−L and U(1)B models, where B and L denote the SM baryon and lepton number symmetries. For U(1)B−L gauge symmetry, each generation of SM fermions is anomaly free and the exotic Z→Z′BLγ decay width is entirely induced by intragenerational mass splittings. In contrast, for U(1)B gauge symmetry, the existence of two distinct sources of chiral symmetry breaking enables a heavy, anomaly-free set of fermions to have an irreducible contribution to the Z→Z′Bγ decay width. We show that the current LEP limits on the exotic Z→Z′Bγ decay are weaker than previously estimated, and low-mass Z′B dijet resonance searches are currently more constraining. We present a summary of the current collider bounds on U(1)B and a projection for a TeraZ factory on the Z→Z′Bγ exotic decay, and emphasize how the Z→Z′γ decay is emblematic of new anomalous U(1) gauge symmetries.

Speaker: Felix Yu (JGU Mainz)

ECFA_Probing_U1_FY.pdf

WG 3: R&D: Session 2 - PID and calorimetry

Detector R&D

Convener: Mary-Cruz Fouz Iglesias (CIEMAT)

78 ARC - a novel RICH detector for a future e+e- collider

Particle identification is a highly desirable attribute of an experiment at a future e+e- collider. For example, high luminosity operation at the Z pole will provide opportunities for precise flavour-physics measurements, for which hadron identification is mandatory. The ability to tag the quark flavour of jets, for instance from Higgs decays, will also be greatly enhanced by high quality hadron identification. The Aerogel RICH Cellular (ARC) detector is a novel RICH system consisting of a dual aerogel-gas radiator system that would provide hadron identification over the required momentum range. Crucially, the ARC is a compact and low-mass detector that can be conveniently integrated into the layout of many of the experiment designs that are being considered for FCC-ee and the ILC. The current status of the ARC design will be presented, and its expected physics performance will be discussed.

Speaker: Martin Tat (University of Oxford)

ARC_Presentation_ECFA_Workshop_DESY_6th_October_2022.pdf

79 Implementation of large imaging calorimeters

The next generation of collider detectors will make full use of Particle Flow algorithms, requiring full imaging calorimeters. The latter have been developed during the past 15 years by the CALICE collaboration and are now reaching maturity. The state-of-the-art and the remaining challenges will be presented for all investigated readout types. We will describe the commissioning, including beam test results, of large scale technological prototypes and the raw performances such as energy resolution, linearity and studies exploiting the distinct features of granular calorimeters regarding pattern recognition. At the time of conference new results obtained in recent (2021/22) beam tests with a technological prototype of a highly granular silicon tungsten electromagnetic calorimeter standalone and combined with the CALICE analogue hadron calorimeter (SiPM on Tile) will be available. Further, the design of experiments addressing the requirements and potential of imaging calorimetry will be discussed. Promising techniques for dedicated devices inverse APD or segmented crystal calorimeters will also be highlighted. Recently, also first results with high resolution timing devices have been obtained. The integration of these devices in the CALICE prototypes is one of the major goals in the coming years.

Prototypes of electromagnetic and hadronic imaging calorimeters developed by the CALICE collaboration provide an unprecedented wealth of highly granular data of hadronic showers for a variety of active sensor elements and different absorber materials. We discuss detailed measurements of the spatial and the time structure of hadronic showers to characterise the different stages of hadronic cascades in the calorimeters, in comparison with GEANT4-based simulations using different hadronic physics models. These studies also extend to the two different absorber materials, steel and tungsten, used in the prototypes. The high granularity of the detectors is exploited in the reconstruction of hadronic energy, both in individual detectors and combined electromagnetic and hadronic systems, making use of software compensation and semi-digital energy reconstruction. The results include new simulation studies that predict the reliable operation of granular calorimeters. Further we show how granularity and the application of multivariate analysis algorithms enable the separation of close-by particles. Granular calorimeters are also an ideal testing ground for the application of machine learning techniques. We will outline how these techniques are applied to CALICE data and in the CALICE simulation framework.

Speakers: Roman Poeschl (None), Roman Poeschl (LAL Orsay)

talk061022.pdf

80 Optimisation of a SIlicon-Tungsten ECAL resolutions for Higgs Factory

Higgs Factories detector will require high precision highly granular ECAL.
The Silicon-Tungsten ECAL is optimised for the particle flow with cell size of 5×5 mm².
We propose here a revisitation of the Silicon-Tungsten ECAL parameters to optimise the energy, timing, position and angle resolutions for given cost (amount of tungsten, number of layers) based on detailed simulations.

Speaker: Vincent Boudry (LLR – CNRS, École polytechnique, Institut Polytechnique de Paris)

2022-10-06_ECAL-Optimisations_ECFAeeWS-2.pdf

81 Dual Readout fiber calorimeter and crystal EM calorimeter for the IDEA detector

The status of the current R&D on an optical fiber based Dual Readout calorimeter will be discussed, including results from test beams at DESY and CERN. Plans for the construction of a new prototype with full containment of the hadronic shower will be shown.
A crystal EM calorimeter addition to the IDEA detector is also discussed, including both simulated performance improvements and future planned R&D.

Speaker: Iacopo Vivarelli (Sussex University)

DESY_DualReadout_Oct2022.pdf

82 Noble Liquid Calorimetry for an FCC-ee Experiment

Noble liquid calorimetry is a well proven technology that successfully operated in numerous particle physics detectors (D0, H1, NA48, NA62, ATLAS, …). Its excellent energy resolution, linearity, stability, uniformity and radiation hardness as well as good timing properties make it a very good candidate for future hadron and lepton colliders. Recently, a highly granular noble liquid sampling calorimeter was proposed for a possible FCC-hh experiment. It has been shown that, on top of its intrinsic excellent electromagnetic energy resolution, noble liquid calorimetry can be optimized in terms of granularity to allow for 4D imaging, machine learning and - in combination with the tracker measurements - particle-flow reconstruction. This talk will discuss the ongoing R&D to adapt noble liquid sampling calorimetry for an electromagnetic calorimeter of an FCC-ee experiment with a focus on signal extraction, noise mitigation and cryostat material budget. In addition to that, performance studies realized with the FCCSW full simulation framework and first electrical tests of a readout electrode prototype will be presented.

Speaker: Brieuc Francois (CERN)

20221006_Brieuc_Francois_Noble_Liquid_Calorimetry_forFCCee_ECFA_Workshop_DESY.pdf

WG1: joined HTE & GLOB session

Convener: Chris Hays (Oxford University)

83 New constraints on extended Higgs sectors from the trilinear Higgs coupling

Investigating the trilinear Higgs coupling $\lambda_{hhh}$ is crucial to determine the structure of the Higgs potential and to probe possible signs of physics beyond the Standard Model (SM). Focusing on the Two-Higgs-Doublet Model as a concrete example, I will discuss the calculation of the dominant two-loop contributions to $\lambda_{hhh}$, and I will show that this coupling can, in certain regions of parameter space, be significantly enhanced with respect to its SM prediction. Taking into account all relevant corrections up to the two-loop level, I will demonstrate that the current experimental bounds on $\lambda_{hhh}$ already rule out significant parts of otherwise unconstrained parameter space of the model. Finally, I will present a benchmark scenario illustrating the interpretation of the current results and future measurement prospects on $\lambda_{hhh}$.

Speaker: Johannes Braathen (T (Phenomenology))

Braathen_ECFA2022.pdf

84 Precise predictions for the trilinear Higgs coupling in arbitrary models

The trilinear coupling of the 125-GeV Higgs boson, $\lambda_{hhh}$, is one of the most important quantities to investigate in the future. It controls the shape of the Higgs potential, and in turn it determines the strength of the electroweak phase transition. It can also exhibit large deviations from its SM predicition, even in scenarios where New Physics is hidden from direct observation (e.g. scenarios with alignment), and the experimental bounds on it are already sufficiently strong to exclude significant parts of (otherwise unconstrained) parameter spaces of Beyond-the-Standard-Model (BSM) theories. It is therefore crucial to have accurate predictions for $\lambda_{hhh}$ for the wide range of BSM models currently investigated.

In this talk, I will present a new public tool, providing predictions for $\lambda_{hhh}$, expressed in terms of the coupling modifier $\kappa_\lambda$, to full one-loop order within arbitrary renormalisable QFTs. This framework allows computing one-, two-, and three-point functions at one loop in an automated way, and furthermore offers a high level of flexibility in the application of pre- or user-defined renormalisation conditions. I will review the main elements of the calculation and demonstrate features of the new program. Finally, I will discuss possible applications and extensions of this tool.

Speaker: Martin Gabelmann (T (Phenomenology))

desyecfa22.pdf

85 Higgs self-coupling projections for future e+e- colliders

Establishing the shape of the Higgs potential is invaluable in paving a path forward for understanding the principles behind the Higgs mechanism. As the Higgs self-couplings are directly related to the Higgs potential, their measurements are crucial to either verify the SM mechanism for electroweak symmetry breaking sector or uncover new physics.
The physics programmes at future $e^+e^-$ colliders provide access to the trilinear Higgs self-coupling, $\lambda_{HHH}$. At Higgs factories, it can only be indirectly accessed via model-dependent fits. More direct information on the $\lambda_{HHH}$ can be obtained from double-Higgs production available at sufficiently high center-of-mass energies. For such a measurement, precision is key, however, small production cross sections pose challenges and set high standards on the analysis techniques. Recent improvements in analysis techniques have been achieved and are expected to improve the Higgs self-coupling projections.
In this contribution, we review current state-of-the-art projections for the Higgs self-coupling measurement at future $e^+e^-$ colliders and discuss key aspects of improvement, focusing on flavour-tagging, b-jet reconstruction, and kinematic fitting.

Speaker: Julie Torndal (FTX (FTX Fachgruppe SLB))

ECFA_Workshop_2022_Talk.pdf

86 The geometric SMEFT

The effective field theory approach to the Standard Model, the SMEFT, has been used to study LHC data with ever increasing theoretical precision and sophistication recently. The explosion in the number of parameters in the SMEFT as a function of operator mass dimension, and the technical challenge or reformulating SM predictions consistently into the SMEFT were very serious problems for years. I will discuss how these challenges have been overcome
using an understanding that the projection of curved scalar field spaces generated by the Higgs - in the Geometric SMEFT.

Speaker: Michael Trott (NBI)

geoSMEFT2022DESY.pdf

Poster Session: including Finger Food Dinner

87 An overview of the International Large Detector (ILD) for a future electron-positron collider

The International Large Detector (ILD) is a detector designed primarily for the International Linear Collider (ILC), a high-luminosity linear electron-positron collider with an initial center-of-mass energy of 250 GeV, extendable to 1 TeV.
The ILD concept is based on particle flow for overall event reconstruction, which requests outstanding detector capabilities including superb tracking, very precise detection of secondary vertices and high-granularity calorimetry. In the past years the design has focused on building sub-detector technological prototypes scalable to the full ILD size, studying their integration into a coherent detector, benchmarking the ILD performance and preparing for an optimization of the overall ILD size and costing. The current status has been made public in an ILD Interim Design Report (IDR, 2020) of interest for any future e+e– collider detector. The poster will summarize the main IDR results.
Recently, the ILD group has been considering widening its activities to explore synergies with studies at other Higgs factories. A new strategy of the ILD group currently under discussion may also be presented.

Speaker: Ties Behnke (DESY)

Poster ILD Ecfa 2022.pdf

88 Di-Higgs with missing transverse momentum at FCC-hh

The determination of the Higgs self-coupling from di-Higgs events with very high precision is one of the clearest benchmarks for the FCC-hh. Its potential has been well established already in several final states. In this talk studies into final states of the di-Higgs system which involve neutrinos are presented. The benefit of studying yet another di-Higgs final state is two-fold: First, any additional events included will add further precision to the measurement. Second, specifically neutrino channels will help to shed light on an experimental aspect for the FCC-hh which has not been well investigated yet: a robust reconstruction of the missing transverse momentum (ETMiss) is crucial for such analyses. It is is clear that ETMiss reconstruction at the FCC-hh will be extremely challenging due to the high pile-up environment, with average interactions per bunch crossing of the order of 1000. In particular, bbWW, bbττ and bbZZ signals are analysed in the final state with 2 light charged leptons in addition to ETMiss, using cut-based as well as multi-variate techniques. Their expected sensitivity is extracted, and the impact of different scenarios for systematic uncertainties, such as the worsening of the ETMiss resolution, is assessed.

Speaker: Birgit Stapf (ATLAS (ATLAS Higgs Physics))

2022-09-30_ECFA-poster-FCChh-HH-bb2lMET-1.pdf

89 Higgs physics studies with ILC

With technically mature design and well understood physics program, ILC is a realistic option for realization of a Higgs factory. With a unique physics reach of a linear collider, ILC will significantly complement projections for HL-LHC. Energy staged data collection, employment of beam polarization and capability to reach a TeV center-of-mass energy enable unique precision measurements of various Higgs couplings including its self-coupling. These precision measurements will allow to probe BSM indirectly beyond the reach of direct search at the LHC. This talk will address the simulation studies based on the ILD detector concept for the Higgs physics program at the ILC.

Speakers: Gordana Milutinovic-Dumbelovic (VINCA Institute of Nuclear Sciences, University of Belgrade), Gordana Milutinovic-Dumbelovic (VINCA Institute of Nuclear Sciences, University of Belgrade)

Gordana_Hamburg.pdf

90 Higgs Self Couplings Measurements at Future proton-proton Colliders

The Higgs boson trilinear and quartic self-couplings are directly related to the shape of the Higgs potential; measuring them with precision is extremely important, as they provide invaluable information on the electroweak symmetry breaking and the electroweak phase transition.
\In this paper, we perform a detailed analysis of double Higgs boson production, through the gluon-gluon fusion process, in the most promising decay channels $b\bar{b} \gamma\gamma$, $b\bar{b} \tau\tau$, and $b\bar{b}b\bar{b}$ for several future colliders: the HL-LHC at 14 TeV and the FCC-hh at 100 TeV, assuming respectively 3 $ab^{-1}$ and 30 $ab^{-1}$ of integrated luminosity.\
In the HL-LHC scenario, we expect an upper limit on the di-Higgs cross section production of 0.76 at 95\% confidence level, corresponding to a significance of 2.8 $\sigma$.
In the FCC-hh scenario, depending on the assumed detector performance and systematic uncertainties, we expect that the Higgs self-coupling will be measured with a precision in the range 4.8-8.5\% at 95\% confidence level.\

Speaker: Paola Mastrapasqua (UCLouvain)

91 IDEA Detector in DD4HEP

Implementation of the Idea Detector in DD4HEP

Speaker: Lorenzo Capriotti (INFN Bologna)

92 Kinematic Fitting at future e+e- Higgs Factories

The well-known initial state of e+e- colliders can be exploited in physics analyses by fits of the measured quantities to kinematic constraints, called kinematic fitting. Compared to LEP, though, the detector precision increased dramatically, while initial-state radiation and beamstrahlung make the initial-state somewhat less well known, making new developments mandatory. This contribution will present recent developments in MarlinKinfit, which are ready to be provided also via Key4HEP. This includes the treatment of photon radiation, improved minimisation engines, so-called "soft" constraints as well as the usage of sophisticated covariance matrix estimates for the measured quantities, thereby exploiting the high-granularity of particle flow detectors.

Speaker: Jenny List (FTX (FTX-SLB))

jlist_ecfa_kinfit_poster_221006.pdf

93 New physics searches with the ILD detector at the ILC

Although the LHC experiments have searched for and excluded many proposed new particles up to masses close to 1 TeV, there are many scenarios that are difficult to address at a hadron collider. This poster gives an overview of recent ILD studies on new particle searches at the ILC. The cases discussed include the light Higgsino, the stau lepton in the coannihilation region relevant to dark matter, and heavy vector bosons coupling to the s-channel in e$^+$e$^-$ annihilation.

Speaker: Carl Mikael Berggren (FLC (FTX Fachgruppe SLB))

94 Particle Flow reconstruction in IDEA with Pandora

The aim of the project is to adopt the Pandora framework to build a Neural Network based algorithm that, from a given collection of energy deposits in the dual readout calorimeter, is able to completely reconstruct a jet in the IDEA detector.

Speaker: Patrizia Azzi (INFN)

posterDesyFCC.pdf

95 Search for non-Standard Model interactions of the top quark at ILC

Top quarks and in general heavy quarks are likely messengers to new physics. The scrutiny of these particles properties must be completed by the measurement of electroweak qqbar production at high energies, in particular for the top-quark. The International Linear Collider will offer favorable low-background environment of e+e- annihilation combined with a high-energy reach.
This talk will review the opportunities for precision measurements of the top and heavy quarks properties at the International Linear Collider, including the search for BSM contributions and CP violation in the top sector.

Speaker: Adrian Irles (IFIC CSIC/UV)

poster_draft3_portrait.pdf

96 Status of the CALICE AHCAL - a highly granular SiPM-on-tile hadron calorimeter

The Analogue Hadron Calorimeter (AHCAL) developed by the CALICE collaboration is a scalable technology for a highly granular hadron sampling calorimeter, made from steel absorber plates and 33 cm^2 plastic scintillator tiles individually read out by silicon photomultipliers (SiPMs). The tiles are individually wrapped in ESR reflector foil. The SPIROC2E front-end chips are integrated into the active layers of the calorimeter. They are designed for minimal power consumption by rapidly cycling the power according to the beam structure of a linear electron-positron collider. The AHCAL provides hit times with a resolution of ~1 ns. In 2017 and 2018, a new large prototype with 38 active layers of 7272 cm^2 size was built. The prototype was assembled using techniques suitable for mass production. The calorimeter was commissioned at DESY and took muon, electron and pion data at the CERN SPS. In 2022, for the first time data were recorded together with the CALICE SiW ECAL technological prototype.

Further AHCAL hardware developments focus on two areas: 1) an alternative readout ASIC (KLauS) that supports continuous readout, needed for a detector at a circular collider, and 2) "Megatiles" as alternative scintillator geometry.

The contribution gives an overview of AHCAL status and ongoing developments.

Speaker: Jiri Kvasnicka (FTX (FTX Fachgruppe DTA))

2022-10-05-ECFA-AHCAL-poster.pdf

97 Studies of di-Higgs production at the FCC-hh in the bbZZ(llvv) final state

The FCC-hh is a proposed circular hadron collider at an energy of 100 TeV. The total integrated luminosity is expected to be around 30 $ab^{-1}$. With such a large dataset, 400 times more double-Higgs events are expected than with the full HL-LHC dataset, allowing to measure the Higgs self-coupling with high precision. As a consequence, also rarer final states, which are not within reach of the (HL)-LHC, have good prospects at the FCC-hh. One such final state is the bbZZ(ll$\nu\nu$) channel, which has only an Branching Ratio of 0.12\%. With a regular cut-based analysis the potential of this channel is very limited.
This study implements a multivariate analysis using neural networks to see if it is a feasible channel that can be used to help to improve the Higgs self-coupling measurement.
Upper limits on the di-Higgs production cross-section are derived in order to assess the potential of this channel.

Speaker: Kevin Laudamus (CMS (CMS Fachgruppe HIGGS))

98 The International Large Detector: Calorimeter system

The International Large Detector (ILD) is a detector designed primarily for the International Linear Collider (ILC), a high-luminosity linear electron-positron collider with an initial center-of-mass energy of 250 GeV, extendable to 1 TeV. This poster will present the current design of its calorimeter system; a highly granular calorimeter in an overall design philosophy called particle flow, developed for optimal global event reconstruction. Open options and critical aspects, as well as prospects for enhanced capabilities in the future will also be presented.

Speaker: Daniel Jeans (KEK)

ECFA-ws-CALO-portrait-compress.pdf

99 The International Large Detector: Tracking system

The International Large Detector (ILD) is a detector designed primarily for the International Linear Collider (ILC), a high-luminosity linear electron-positron collider with an initial center-of-mass energy of 250 GeV, extendable to 1 TeV. This poster will present the current design of its tracking system; a precision vertex detector positioned very close to the interaction point is followed by a hybrid tracking layout, realized as a combination of silicon tracking with a time projection chamber. Open options and critical aspects, as well as prospects for enhanced capabilities in the future will also be presented.

Speakers: Maxim Titov (CEA Saclay, Irfu), Paul Colas (CEA Saclay, IRFU)

2022_10_DESY-HH_ECFA-WORKSHOP_POSTER_ILD-TrackingSystem_v04102022.pptx

100 The Semi-Digital Hadron Calorimeter (SDHCAL) for future Higgs Factories

The Semi-Digital Hadron Calorimeter (SDHCAL) is a highly segmented sampling hadronic calorimeter. using large Glass Resistive Plate Chambers (GRPC) as active medium with embedded readout Printed Circuit Board (PCB) hosting 1 cm² copper pads (read independently) on one side and ASIC readout chips (HARDROC) on the other side.

A technological prototype of ~1m3 developed within the CALICE collaboration have shown excellent results in energy resolution and shower separation. Refined analysis techniques are still being developed. Latest developments address improving spatial uniformity and use of the particle incidence angle in the energy reconstruction.

Experiments at future Higgs Factories can require length-scalable GRPCs (maximum 3 meters). To design such detectors, all aspects had to be rethink : gas distribution, PCB with latest HARDROC chip, DAQ interface board, holding cassette and new way to manufacture and assemble the absorber plates.

A new phase of R&D is focused on exploiting time precision, turning the SDHCAL on a 5D device, leading to better shower reconstruction and better showers separation. Multigap RPC (MRPC) can provide excellent time resolution of 50-100 ps. This requires new readout chips, PETIROC ASIC with its internal TDC, and new PCB. Developments related to the MRPC and the needed electronic are ongoing.

Speaker: Dr Mary-Cruz Fouz (CIEMAT)

101 Very forward calorimeters at ILC/ILD

Detectors at future e+e- colliders need special calorimeters in the very forward region for a fast estimate of instantaneous and precise measurement of the integrated luminosity. In ILD detector concept, two such calorimeters are foreseen, LumiCal and BeamCal. Both are designed as sandwich calorimeters with very thin sensor planes to keep the Molière radius small, facilitating measurement of the high-energy electron showers. Silicon sensor prototypes and dedicated FE ASICs have been developed and produced matching the timing and dynamic range requirements. The status of the calorimeter prototype performance in the recent beam tests at DESY will be presented, against the expected performance obtained from simulation.

Speaker: Ivanka Bozovic Jelisavcic (VINCA Institute of Nuclear Sciences, University of Belgrade (RS))

ECFA22_FCAL_poster.pdf

102 Measurement of the Higgs to diphoton branching fraction at 3 TeV CLIC

Here we address the results of a full simulation of experimental measurement of the Standard Model Higgs boson decaying to a pair of photons at 3 TeV center-of-mass energy at the Compact Linear Collider (CLIC). Since photons do not couple to Higgs boson at a tree level, any deviation of the Higgs to photons coupling may indicate a New Physics. We show that the product of the Higgs production cross-section in W+W− fusion and BR (H → γγ) as the observable for determination of the Higgs to photons coupling, can be measured with a relative statistical precision of 5.5%, assuming the integrated luminosity of 5 ab−1 and unpolarized beams.

Speaker: Ivanka Bozovic Jelisavcic (VINCA Institute of Nuclear Sciences, University of Belgrade (RS))

ECFA_Workshop_poster_Goran_Kacarevic.pdf

Public Lecture Hitoshi Murayama

Convener: Jon Butterworth (UCL)

video1816578447.mp4

Friday, 7 October

Plenary: Summaries & Plans (WG3 & WG2)

Convener: Alain Blondel (Universite de Geneve (CH) and CNRS (France))

103 Summary on Generators

Speaker: Alan Price (University of Siegen)

summary_talk.pdf

video1424770663.mp4

104 Summary on Simulation & Reconstruction

Speaker: Ulrich Einhaus (FTX (Fachgruppe SLB))

2022_10_07_ECFA_SimReco_Summary.pdf

video2424770663.mp4

105 Plans for WG2

Speaker: Patrizia Azzi (INFN)

PlansWG2-ECFA@DESY2022 (1).pdf

video3424770663.mp4

106 WG3 - Highlights and plans on tracking and PID

Speaker: Giovanni Marchiori (APC Paris - CNRS/IN2P3 and Université de Paris)

2022:10:07 - ECFA - tracking and PID.pdf

video4424770663.mp4

107 WG3 - Highlights and plans on calorimetry

Speakers: Mary-Cruz Fouz (CIEMAT), Mary-Cruz Fouz Iglesias (CIEMAT)

CaloSummary.pdf

video5424770663.mp4

10:30 Coffee break

Plenary: Summaries & Plans (WG1)

Convener: Patrick Janot

108 Highlights & Plans WG1-PREC

Speaker: Andreas Meyer (DESY)

video6424770663.mp4

WG1-PREC_Highlights_and_Plans_221005.pdf

109 Highlights & Plans WG1-GLOB

Speaker: Alexander Grohsjean (CMS (CMS Fachgruppe TOP))

glob-summary.pdf

video7424770663.mp4

110 Highlights & Plans WG1-SRCH

Speaker: Aleksander Filip Zarnecki (Faculty of Physics, University of Warsaw)

ECFA WG1-SRCH highlight & plans v4.pdf

video8424770663.mp4

111 Highlights & Plans WG1-FLAV

Speaker: David Marzocca (INFN Trieste)

FLAV_highlights_plans.pdf

video9424770663.mp4

112 Highlights & Plans WG1-HTE

Speaker: Chris Hays (Oxford University)

ECFAOctWS.pdf

video10424770663.mp4

12:40 Lunch

Plenary: General Outlook

Convener: Juan Fuster (IFIC-Valencia)

113 Timeline and Next Steps of the ECFA Higgs Factory Study

Speaker: Aidan Robson (University of Glasgow)

ecfaHiggsPlansOct22_robson_v1a.pdf

video1193949340.mp4

114 Path towards a Higgs Factory

Speaker: Joachim Mnich (DESY)

JM DESY Oct 2022.pptx

video2193949340.mp4

115 Closing & Farewell

Speaker: Karl Jakobs (University of Freiburg)

ECFA_Hamburg_Closeout.pdf

video3193949340.mp4