from September 29, 2015 to October 2, 2015

DESY Hamburg

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## Contribution List

Displaying 124
contributions
out of
124

Session:
Particle Phenomenology

Lepton flavor violating Higgs decays can arise in flavor symmetry
models where the Higgs sector is responsible for both the electroweak and
the flavor symmetry breaking. Here we advocate an $S_4$
three-Higgs-doublet model where tightly constrained flavor changing neutral
currents are suppressed by a remnant $Z_3$ symmetry. A small breaking of
this $Z_3$ symmetry can explain the $2.4\,\sigma$
... More

Presented by Mr. Erik SCHUMACHER
on
30 Sep 2015
at
2:15 PM

Session:
Strings & Mathematical Physics

We study the strong coupling behaviour of 1/4 BPS latitude Wilson loops in N=4 SYM theory, computing the one-loop corrections to the relevant classical string solution in AdS5xS5 in sigma-model perturbation theory.
The approach is based on the application of the Gel’fand-Yaglom method to compute the relevant functional determinants for the fluctuations of the type IIB Green-Schwarz action expan
... More

Presented by Mr. Edoardo VESCOVI
on
1 Oct 2015
at
4:05 PM

Session:
Cosmology & Astroparticle Physics

A simple TeV scale model for baryon and lepton number violation is presented, where neutrino mass arises via a one loop radiative seesaw effect and B-violation obeys \Delta B = 2 selection rule, leading to observable neutron-antineutron oscillations. The stability of proton is connected to the neutrino mass generation. Matter-antimatter asymmetry is generated in this model via resonant baryogenesi
... More

Presented by Dr. Bhupal DEV
on
1 Oct 2015
at
2:45 PM

Session:
Strings & Mathematical Physics

Two-dimensional gauged linear sigma models with N=(2,2) supersymmetry are a powerful tool for studying the worldsheet theories of type II string compactifications. We construct a certain class of non-Abelian gauged linear sigma models that exhibit an interesting phase structure emerging from non-Abelian strong coupling dynamics. The observed phase structure leads to a duality proposal amongst thes
... More

Presented by Mr. Andreas GERHARDUS
on
30 Sep 2015
at
4:20 PM

Session:
Cosmology & Astroparticle Physics

We propose a new method that allows to place an upper limit on the dark matter elastic scattering cross section with nucleons which is independent of the velocity distribution. Our approach combines null results from direct detection experiments with indirect searches at neutrino telescopes, and goes beyond previous attempts to remove astrophysical uncertainties in that it directly constrains the
... More

Presented by Mr. Sebastian WILD
on
30 Sep 2015
at
2:15 PM

Session:
Particle Phenomenology

The ATLAS collaboration recently found a 3 sigma excess in the search for events with large missing transverse energy, jets, and a dilepton peaked on the Z mass region. We study this excess in the minimal supersymmetric standard model (MSSM), especially focusing on the well-motivated split supersymmetry (SUSY) spectrum. We consider the following decay chain: gluino to gluon and Higgsino which su
... More

Presented by Dr. Takahiro TERADA
on
1 Oct 2015
at
4:35 PM

Session:
Particle Phenomenology

We propose an adjoint $SU(5)$ GUT model with a $T_{7}$ family symmetry and an extra $Z_{2}\otimes Z_{2}^{\prime }\otimes Z_{3}\otimes Z_{4}\otimes Z_{12}$ discrete group, that successfully describes the prevailing Standard Model (SM) fermion mass and mixing pattern. The observed hierarchy of the charged fermion masses and the quark mixing angles arises from the $Z_{3}\otimes Z_{4}\otimes Z_{12}$ s
... More

Presented by Dr. Arbelaez CAROLINA
on
30 Sep 2015
at
2:30 PM

Affleck-Dine baryogenesis after D-term inflation and a solution to the baryon-DM coincidence problem

Session:
Cosmology & Astroparticle Physics

We investigate the Affleck-Dine baryogenesis after D-term inflation with a positive Hubble-induced mass term for a B-L flat direction. It stays at a large field value during D-term inflation, and just after inflation ends it starts to oscillate around the origin of the potential due to the positive Hubble-induced mass term. The phase direction is kicked by higher-dimensional Kahler potentials to
... More

Presented by Mr. Masaki YAMADA
on
1 Oct 2015
at
3:15 PM

Session:
Cosmology & Astroparticle Physics

One aim of cosmic ray measurements is to search for possible signatures of annihilating or decaying dark matter. The excess of positrons measured at the top of the atmosphere has attracted a lot of attention in this context. On the other hand it has been proposed that the data might challenge the established diffusion model for cosmic ray propagation. We investigate variations in the diffusion mod
... More

Presented by Ms. Annika REINERT
on
30 Sep 2015
at
5:05 PM

Session:
Strings & Mathematical Physics

We study higher spin currents in the O(N) vector models using analytic conformal bootstrap. For large $N$ we compare the predictions of the bootstrap for anomalous dimensions of higher spin currents against the available perturbative computations. We then generalize to arbitrary loop order. For small $N$ our results can be tested using numerical bootstrap or future experiments.

Presented by Mr. Alexander ZHIBOEDOV
on
1 Oct 2015
at
2:00 PM

Run-II of the LHC is probing the Standard Model of particle physics at
unprecedented energies and precision. At such large energy scales
higher-order electroweak (EW) corrections are strongly enhanced due to
the presence of large Sudakov logarithms. In my talk I will present a
fully automated implementation of next-to-leading order (NLO) EW
corrections in the OpenLoops matrix-element generato
... More

Presented by Jonas LINDERT
on
30 Sep 2015
at
2:45 PM

Session:
Particle Phenomenology

Transverse momentum spectra of massive bosons at hadron colliders provide important tests of the Standard Model. In the crucial region, where the boson's invariant mass M is much smaller than its transverse momentum qT, the spectra are very sensitive to initial state radiation.
Applying soft-collinear effective theory, a universal framework for its description has been established and the relevan
... More

Presented by Dr. Thomas LÜBBERT
on
30 Sep 2015
at
4:35 PM

We show that the event excess observed by the IceCube collaboration at TeV–PeV energies, usually interpreted as evidence for astrophysical neutrinos, can be explained alternatively by the scattering of highly boosted dark matter particles. Specifically, we consider a scenario where a ~ 4 PeV scalar dark matter particle φ can decay to a much lighter dark fermion χ, which in turn scatters off nu
... More

Presented by Dr. Xiaoping WANG
on
30 Sep 2015
at
4:50 PM

Session:
Particle Phenomenology

The Minimal Supersymmetric Standard Model (MSSM) is known for the possibility of creating (unwanted) charge and color breaking minima. Well-known bounds on MSSM parameters are known for special scenarios with an alignment of vacuum expectation values (vevs) in the direction of up-type or dow-type fields only. From the one-loop stability condition in the up-type Higgs direction, we find a new const
... More

Presented by Dr. Wolfgang Gregor HOLLIK
on
1 Oct 2015
at
5:05 PM

Session:
Strings & Mathematical Physics

We consider six-dimensional supergravity compactified on orbifolds with Wilson lines and flux. Both orbifold singularities and flux lead to chiral fermions in four dimensions. The six-dimensional bulk anomaly, the fixed point anomalies and also the four-dimensional chiral anomaly are cancelled by the Green-Schwarz mechanism. The effective four dimensional theory contains two axions with interestin
... More

Presented by Mr. Markus DIERIGL
on
1 Oct 2015
at
5:05 PM

Models of 4D $\mathcal{N}=1$ supergravity coupled to chiral multiplets with vanishing scalar potential have been denoted as no-scale. Of particular interest in the context of string theory are models which additionally possess a shift-symmetry. In this case there exists a dual description of chiral models in terms of real linear multiplets. We classify all shift-symmetric no-scale supergravities i
... More

Presented by David CIUPKE
on
30 Sep 2015
at
5:35 PM

Session:
Particle Phenomenology

We present a general classification of minimal models where Dark Matter coannihilates with another particle, X. Besides this new particle, such coannihilation processes typically require the existence of a mediator, M. Assuming tree-level and renormalizable interactions we construct all possible Dark Matter, X and M field content which respects gauge and Lorentz invariance. Using our framework one
... More

Presented by Dr. Michael BAKER
on
30 Sep 2015
at
4:50 PM

Correlation functions of local gauge-invariant operators are natural
observables inany conformal quantum field theory.
In N=4 SYM a particular role is played by the multipoint supercorrelators
of thestress-tensor multiplet.
Their chiral truncation in the light-cone limit coincides with the scattering
superamplitudes.
We propose a novel approach to calculating such correlators based on the
L
... More

Presented by Dmitry CHICHERIN
on
1 Oct 2015
at
4:20 PM

We show that dark matter abundance and the inflationary scale could be intimately related. Standard Model extensions with Higgs mediated couplings to new physics typically contain extra scalars whose excursions at the end of inflation can be very large.
If their coupling to the Standard Model is weak, they will not thermalize and may easily constitute too much dark matter reminiscent to the mod
... More

Presented by Mr. Tommi TENKANEN
on
1 Oct 2015
at
5:35 PM

Session:
Cosmology & Astroparticle Physics

The next-to-minimal supersymmetric standard model (NMSSM) is a possible extension of the minimal supersymmetric standard model (MSSM) that introduces an additional gauge singlet superfield to solve the mu-problem of the MSSM. In this model there exists a discrete Z_3 symmetry, which can be spontaneously broken in the early universe leading to the formation of domain walls. In this work, we investi
... More

Presented by Mr. Ken'ichi SAIKAWA
on
1 Oct 2015
at
5:05 PM

Session:
Particle Phenomenology

We present theoretical predictions for the mono-$Z$ production
in the search for dark matter at the LHC with next-to-leading order QCD corrections
and parton-shower effects.
The calculation is performed in the framework of {\tt MadGraph5$\_$aMC@NLO}.
We find that the high order QCD corrections are sizable, and can reduce the theoretical uncertainties.
We also investigate the discovery potenti
... More

Presented by Dr. Jian WANG
on
30 Sep 2015
at
5:20 PM

Session:
Cosmology & Astroparticle Physics

While dark matter self-interactions may solve several problems with structure formation, so far only the effects of two-body scatterings of dark matter particles have been considered. We show that, if a subdominant component of dark matter is charged under an unbroken U(1) gauge group, collective dark plasma effects need to be taken into account to understand its dynamics. Plasma instabilities can
... More

Presented by Dr. Christian SPETHMANN
on
30 Sep 2015
at
2:45 PM

Recently, a new class of models beyond the standard model was proposed wherein the baryonic and leptonic currents separately source U(1) gauge fields. In this talk, I describe the two most minimal viable models known. In these models, the requirement of anomaly cancellation conditions automatically imply the existence of a stable Fermionic dark matter candidate. In addition to dark matter phen
... More

Presented by Dr. Hiren PATEL
on
30 Sep 2015
at
4:20 PM

Session:
Cosmology & Astroparticle Physics

We consider scenarios where the dark matter becomes unstable due to a non-minimal coupling to gravity. We show that the dark matter can decay into Standard Model particles with a lifetime which is potentially accessible to gamma-ray or neutrino telescopes. We determine the decay branching fractions in some simple scenarios and we set limits on the size of the dark matter non-minimal coupling param
... More

Presented by Sebastian INGENHÜTT
on
30 Sep 2015
at
5:35 PM

Session:
Cosmology & Astroparticle Physics

I will present a new model of dark matter where the candidate arises from a fermionic 10 representation of SO(10) Grand unified theory. Stability follows from the gauge structure itself, and the low energy dark matter phenomenology is that of a TeV-scale left-right model augmented by a fermion bi-doublet.

Presented by Mr. Sofiane BOUCENNA
on
30 Sep 2015
at
4:35 PM

Session:
Particle Phenomenology

We revisit the singlet complex scalar Higgs portal model. We introduce the U(1)_{\phi} breaking terms. These terms make small mass splitting. The small mass splitting make the displaced decay which could be a non-SM background signal. We find feasible way to discover the displaced higgs portal dark matter at the LHC.

Presented by Mr. Dong Woo KANG
on
30 Sep 2015
at
5:05 PM

Session:
Cosmology & Astroparticle Physics

The Peccei-Quinn (PQ) mechanism provides an elegant solution to the strong CP problem. However astrophysical constraints on axions require the PQ breaking scale to be far higher than the electroweak scale. In supersymmetric models the PQ symmetry can be broken at an acceptable scale if the effective potential for the pseudo-modulus in the axion multiplet develops a minimum at large enough field va
... More

Presented by Mr. Toby OPFERKUCH
on
1 Oct 2015
at
4:05 PM

Session:
Particle Phenomenology

Effective field theory (EFT) provides an efficient
framework to study the phenomenology of extended Higgs sectors
at the LHC. One caveat is that assuming a clear hierarchy of scales strongly suppresses the size of new physics deviations in an environment where partonic processes can probe a wide range of scales. We consider several modifications of the Higgs sector: a
singlet and doublet exten
... More

Presented by Dr. David LOPEZ-VAL
on
1 Oct 2015
at
2:30 PM

Session:
Particle Phenomenology

We calculate the electroweak corrections to the Higgs-Strahlung processes at the LHC, pp -> Vh, within the Two Higgs Doublet Model(THDM). The freedom in triple-Higgs couplings would give strong elevation to the cross section. Even for fairly heavy Higgs bosons, the relative corrections could also reach -20%.

Presented by Taoli CHENG
on
30 Sep 2015
at
2:00 PM

Session:
Strings & Mathematical Physics

TBA

Presented by Christoph MAYRHOFER
on
30 Sep 2015
at
2:50 PM

I will discuss the effective action of F-theory at order \alpha'^3 from a 12 dimensional perspective. Upon compactification on elliptic Calabi-Yau fourfolds, I will show how the non-trivial vacuum profile for the axio-dilaton leads to a new, genuinely N=1 correction to the 4-dimensional effective action.

Presented by Raffaele SAVELLI
on
30 Sep 2015
at
3:15 PM

Session:
Particle Phenomenology

Grand unified theories have been with us for more than four decades. While attractive, the standard SU(5) and SO(10) models fail to shed light on the flavour problem since, just like the Standard Model, they too place the fermions in three copies of representations of the enlarged gauge group.
What about the possibility of having family unification by putting all fermions in a single represent
... More

Presented by Dr. Renato FONSECA
on
30 Sep 2015
at
3:00 PM

Session:
Particle Phenomenology

The anomalous magnetic moment of the muon is, by today, one of the most appealing signs for Physics Beyond the Standard Model. In this work, we study the Two-Higgs-Doublet Model and compute, up to two-loop order, the complete set of fermionic contributions for the anomaly. We are able to fully reproduce some recent results found in the literature and we show that, for a large region of the parame
... More

Presented by Dr. Adriano LANA CHERCHIGLIA
on
1 Oct 2015
at
2:15 PM

Solid-on-solid (SOS) models in statistical physics describe the
(two-dimensional) interface between two media. To model the shape of the interface we assign a (discrete) height variable to each vertex of a square lattice. The surface tension is taken into account by interactions between these height variables. In case the nearest-neighbouring heights differ by one unit, and the interactions occur
... More

Presented by Jules LAMERS
on
30 Sep 2015
at
5:05 PM

Session:
Particle Phenomenology

We present GM2Calc, a stand-alone C++ program which calculates the supersymmetric contributions to the anomalous magnetic moment of the muon in the Minimal Supersymmetric Standard Model. Besides the one-loop contributions, two-loop corrections coming from SUSY one-loop diagrams with an additional photon exchange or a fermion/sfermion loop insertion as well as two-loop corrections to SM-like one-lo
... More

Presented by Mr. Markus BACH
on
1 Oct 2015
at
2:00 PM

I discuss the scenario of a dark U(1) or SU(N) gauge group coupled to the Standard Model via the Higgs portal. It turns out that minimal CP-conserving hidden Higgs sectors entail stable massive gauge fields which fall into the WIMP category of dark matter candidates. For SU(N), N>2, DM consists of three components, two of which are degenerate in mass. In all of the cases, there are substantial reg
... More

Presented by Dr. Christian GROSS
on
30 Sep 2015
at
3:30 PM

Session:
Strings & Mathematical Physics

The quantization of the Teichmueller spaces of Riemann surfaces
has found important applications to conformal field theory
and N=2 supersymmetric gauge theories. The aim
of the talk is to construct generalizations of the
quantum Teichmueller theory which would, in particular,
describe the quantum theory of the Teichmueller spaces
of Super-Riemann surfaces.
The starting point of the project
... More

Presented by Nezhla AGHAEI
on
1 Oct 2015
at
5:35 PM

Session:
Particle Phenomenology

We present a framework to generate the mass hierarchies and mixing angles of the fermionic sector of the Standard Model with two extra Higgs doublets and one right-handed neutrino. The masses of the first and second generation are generated by small quantum effects, explaining the hierarchy with the third generation.
The model also generates a natural hierarchy between the first and second genera
... More

Presented by Ms. Ana SOLAGUREN-BEASCOA
on
30 Sep 2015
at
2:00 PM

Session:
Particle Phenomenology

Searches for supersymmetry (SUSY) often rely on a combination of hard physics objects (jets, leptons) along with large missing transverse energy to separate New Physics from Standard Model hard processes. We consider a class of ``double-invisible'' SUSY scenarios: where squarks, stops and sbottoms have a three-body decay into {\em two} (rather than one) invisible final-state particles. This occurs
... More

Presented by Dr. Jia LIU
on
1 Oct 2015
at
3:15 PM

In this work we consider a set of soft supersymmetry breaking terms within the NMSSM which leads to a small hierarchy between the supersymmetry breaking scale and the electroweak scale.
Specifically only the gaugino masses and the soft term in the Higgs sector are non-vanishing at the GUT scale. This pattern can be found in gaugino mediated models and in higher-dimensional orbifold GUTs.
We al
... More

Presented by Mrs. Lucila ZÁRATE
on
1 Oct 2015
at
4:35 PM

I will present the calculation of the N3LO QCD correction to the production of a Higgs boson via gluon fusion at the LHC in the limit of infinite top mass. In particular I will give an overview of computational methods used and discuss the reduction of theoretical uncertainties.

Presented by Franz HERZOG
on
30 Sep 2015
at
5:20 PM

Session:
Particle Phenomenology

I present recent calculation of 2-loop corrections to the lightest Higgs boson mass in the minimal R-symmetric supersymmetric Standard Model using the effective potential approximation.

Presented by Mr. Wojciech KOTLARSKI
on
1 Oct 2015
at
3:00 PM

Higgs pair production is key to extract information on the Higgs potential as it consists the simplest process which is sensitive to the trilinear Higgs coupling. A considerable amount of work has been devoted recently towards providing accurate SM predictions and investigating the prospects of observing the process at the LHC. While the SM rates are small (35 fb) at 14 TeV, the process can receiv
... More

Presented by Eleni VRYONIDOU
on
30 Sep 2015
at
5:05 PM

Session:
Particle Phenomenology

I will talk about the more technical aspects of calculations of higher-order corrections to single and double Higgs boson production.

Presented by Dr. Jens HOFF
on
30 Sep 2015
at
4:50 PM

Session:
Particle Phenomenology

As the number of non-perturbative parameters appearing in the heavy quark expansion for inclusive decays proliferates at higher orders, one cannot extract all of these from data, but needs to rely on theoretical estimates. I will explain a systematic method to estimate these parameters.

Presented by Dr. Johannes HEINONEN
on
1 Oct 2015
at
5:05 PM

Session:
Particle Phenomenology

Fermion dark matter interacting with the standard model through a Higgs portal suggests the presence of new mediator states at the electroweak scale. Collider searches for the mediators are a powerful tool to experimentally probe the Higgs-portal interactions, complementary to direct dark matter detection searches. In this talk, I discuss search strategies and the discovery range for the mediators
... More

Presented by Susanne WESTHOFF
on
30 Sep 2015
at
3:15 PM

Session:
Particle Phenomenology

The interpretation of LHC searches for additional Higgs bosons has so far been restricted to cases without interference between close-by states. Phenomenological consequences of such interference terms will be presented. In the MSSM, the two heavier neutral Higgs bosons have similar masses in a wide part of the parameter space. Therefore, especially in the presence of CP-violating complex phases,
... More

Presented by Elina FUCHS
on
1 Oct 2015
at
4:20 PM

Session:
Particle Phenomenology

We present a variety of dark matter models with mediator particles, ranging from simplified setups to elaborated models with definite predictions. We explore the parameter space regions not excluded by cosmological observations. We show that there is an important complementarity between these bounds and LHC searches for the mediators themselves. These include monojet and dijet searches, as well as
... More

Presented by Dr. Mikael CHALA
on
30 Sep 2015
at
4:20 PM

Session:
Particle Phenomenology

R-Symmetry is an additional symmetry which can be imposed on a supersymmetric model,
leading to interesting phenomenological consequences like the prediction of Dirac Gauginos.
A model with a minimal implementation of this symmetry is the MRSSM and in this talk an analysis
of its Higgs sector, as well as its dark matter and LHC phenomenology will be presented.
This model includes a singlet
... More

Presented by Mr. Philip DIESSNER
on
1 Oct 2015
at
3:15 PM

Session:
Particle Phenomenology

In this talk I will discuss an azimuthal angle correlation between the two hardest jets in the top quark pair production at the LHC. The event samples are generated by merging the tree level matrix elements for the ttbar plus up to 2 or 3 partons with parton showers. I show that the generated event samples reproduce a strong correlation in the azimuthal angle difference between the two hardest jet
... More

Presented by Junya NAKAMURA
on
1 Oct 2015
at
4:35 PM

Session:
Particle Phenomenology

In this talk we give an overview over recent developments within GoSam, a publicly available package for the automated calculation of next-to-leading order corrections within and beyond the Standard Model. Besides the current developments we discuss the latest phenomenological applications and present results that are relevant for the Run 2 of the LHC.

Presented by Mr. Nicolas GREINER
on
30 Sep 2015
at
3:00 PM

Session:
Particle Phenomenology

The idea that dark matter forms part of a larger dark sector is very intriguing, given the high degree of complexity of the visible sector. In this paper, we discuss lepton jets as a promising signature of an extended dark sector. As a simple toy model, we consider an
O(GeV) DM fermion coupled to a new U(1)' gauge boson (dark photon) with a mass of order GeV and kinetically mixed with the Standar
... More

Presented by Mr. Malte BUSCHMANN
on
30 Sep 2015
at
4:35 PM

The detection of gamma lines from dark matter annihilation has been seen as a "smoking gun" signature for the existence of dark matter.
However, it turns out that this signature if far from being a generic feature of dark matter models. In fact in most models tree level annihilation to Standard Model particles and Final State Radiation off them leads to a gamma ray continuum which makes the line
... More

Presented by Dr. Juri SMIRNOV
on
30 Sep 2015
at
5:20 PM

Session:
Particle Phenomenology

We present an interpretation of searches for dark matter in a simplified model approach. Considering Majorana fermion dark matter and neutral vector mediators with axial-vector interaction we compare the limits obtained in mono-jet searches at the LHC with limits on the spin-dependent scattering cross-section set by the IceCube collaboration. We discuss the validity of the EFT limit and place new
... More

Presented by Dr. Jan HEISIG
on
30 Sep 2015
at
4:05 PM

Session:
Cosmology & Astroparticle Physics

In the early Universe, any particle carrying a conserved quantum number and in chemical equilibrium with the thermal bath will unavoidably inherit a particle-antiparticle asymmetry. A new particle of this type, if stable, would represent a candidate for asymmetric dark matter (DM) with an asymmetry directly related to the baryon asymmetry. We study this possibility for a minimal DM sector constitu
... More

Presented by Dr. Martin KRAUSS
on
30 Sep 2015
at
3:15 PM

Session:
Particle Phenomenology

We present the calculation, in a completely automated approach, of the NLO EW corrections to ttH, ttZ and ttW production at hadron colliders within the MadGraph5_aMC@NLO framework. We discuss also the impact of NLO QCD corrections on ttH, ttV and ttVV production with V=W, Z, gamma. Relevant distributions for the 13-TeV LHC are considered and inclusive results from 8 to 100 TeV are shown, also for
... More

Presented by Dr. Davide PAGANI
on
30 Sep 2015
at
2:30 PM

Session:
Strings & Mathematical Physics

Natural (axionic) inflation provides a well-motivated and predictive scheme for the description of the early universe. It leads to sizeable primordial tensor modes and thus a high mass scale of the inflationary potential. Naively this seems to be at odds with low (TeV) scale supersymmetry, especially when embedded in string theory. I will outline in the talk that low scale supersymmetry is compati
... More

Presented by Rolf KAPPL
on
1 Oct 2015
at
2:50 PM

Session:
Particle Phenomenology

The MSSM with complex parameters has emerged as an attractive SUSY candidate providing new sources of CP-violation, which are well motivated in the context of the observed imbalance between matter and antimatter in the universe. In order to study the effects of the complex parameters, which enter via loop contributions, an accurate prediction for the Higgs production cross-section is required. In
... More

Presented by Shruti PATEL
on
1 Oct 2015
at
4:05 PM

Session:
Strings & Mathematical Physics

Phenomenologically appealing string vacua with either the Standard Model or some GUT spectrum and suitable orders of magnitudes of matter couplings are essential to establish string theory as the framework that unifies all fundamental interactions. I will present here recent results on the quest for such vacua based on Type II string theory with D-branes, and I will discuss their impact on new phy
... More

Presented by Prof. Gabriele HONECKER
on
30 Sep 2015
at
2:00 PM

Session:
Particle Phenomenology

Weak boson pair production processes are very sensitive to the gauge structure of the electroweak (EW) Standard Model. In certain regions of phase space EW corrections lead to significant distortions of differential distributions and their omission could easily be misinterpreted as signs of new physics. Providing not only QCD but also EW corrections for weak boson pair production processes in a fu
... More

Presented by Lukas SALFELDER
on
30 Sep 2015
at
2:15 PM

Session:
Cosmology & Astroparticle Physics

I will discuss that for Dirac neutrinos there could, in addition to the standard thermal cosmic neutrino background (CνB),
also exist a non–thermal neutrino background with comparable number density.
Today's relic density of the non–thermal background can be as large as 0.5*n_gamma.
It is constrained by the observational limits on the effective number of massless degrees of freedoms, N_eff
... More

Presented by Mr. Andreas TRAUTNER
on
1 Oct 2015
at
2:30 PM

Session:
Cosmology & Astroparticle Physics

We derive a non-perturbative equation for the large scale structure power spectrum of long-wavelength modes. We use an operator product expansion together with relations between the three-point function and power spectrum in the soft limit. The resulting equation encodes the coupling to ultraviolet (UV) modes in two time-dependent coefficients, which may be obtained from
response functions to (an
... More

Presented by Laura SAGUNSKI
on
1 Oct 2015
at
4:50 PM

Session:
Cosmology & Astroparticle Physics

Susceptibilities of conserved charges such as baryon minus lepton
number enter baryogenesis computations, since they provide the relationship
between conserved charges and chemical potentials. Their next-to-leading
order corrections are of order $ g $, where $ g $ is a
generic Standard Model coupling. They are due
to soft Higgs boson exchange, and have been calculated recently,
together w
... More

Presented by Mr. Marc SANGEL
on
1 Oct 2015
at
3:00 PM

Session:
Particle Phenomenology

The spectroscopy of charmonium and exotic states with hidden charm together with the spectroscopy of charmed and strange baryons is discussed. It is a good testing tool for the theories of strong interactions, including: QCD in both the perturbative and non-perturbative regimes, LQCD, potential models and phenomenological models [1, 2, 3]. An understanding of the baryon spectrum is one of the prim
... More

Presented by Dr. Barabanov MIKHAIL
on
1 Oct 2015
at
5:20 PM

Session:
Cosmology & Astroparticle Physics

In composite Higgs scenario, interactions to generate the top Yukawa coupling provide the Higgs potential due to the explicit breaking of a global symmetry. However, such a scenario generically requires a little cancellation in the leading contribution in order to achieve the correct electroweak symmetry breaking with VEV = 246 GeV. We, instead, consider the possibility that the dark matter (DM) s
... More

Presented by Dr. Masaki ASANO
on
30 Sep 2015
at
4:05 PM

Session:
Particle Phenomenology

The NMSSM represents an elegant and well motivated alternative description for the observed phenomenology in high energy physics. In this theory a scalar singlet together with its superpartner is added to the Higgs-sector of the Minimal Supersymmetric Standard Model (MSSM). In order to allow significant testing of the NMSSM by experiments precise predictions for the parameters of the theory are a
... More

Presented by Peter DRECHSEL
on
1 Oct 2015
at
2:45 PM

Session:
Strings & Mathematical Physics

Non-perturbative aspects of N=2 SUSY gauge theories of class S are encoded in the algebra of functions on the moduli space M-flat of flat SL(N)-connections on Riemann surfaces. Expectation values of Wilson and 't Hooft line operators are related to holonomies of flat connections and, in the low-energy effective theory, to Fock-Goncharov coordinates on M-flat.
We determine the non-commutative alg
... More

Presented by Mrs. Ioana COMAN-LOHI
on
30 Sep 2015
at
4:50 PM

Session:
Particle Phenomenology

Despite of its tremendous success various theoretical and experimental issues seem to indicate the need to go beyond the Standard Model framework. One of the most promising ways to address the open questions is offered by the Grand Unification paradigm. Its main experimental signature is the prediction of proton decay and with the new generation of experiments under way (Hyper-K, DUNE, \ldots) an
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Presented by Timon MEDE
on
30 Sep 2015
at
2:45 PM

Session:
Particle Phenomenology

We discuss an improved determination of the up- and down-quark distributions in the proton using recent data on charged lepton asymmetries from $W^\pm$ gauge-boson production at the LHC and Tevatron. The analysis is performed in the framework of a global fit of parton distribution functions. The results are consistent with a non-zero iso-spin asymmetry of the sea, $x(\bar d - \bar u)$, at small va
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Presented by Sergey ALEKHIN
on
1 Oct 2015
at
4:05 PM

Session:
Cosmology & Astroparticle Physics

We will discuss the relic density of TeV-scale wino-like neutralino dark matter in the pMSSM. We have recently developed a framework enabling us to compute the Sommerfeld enhanced relic density
in general pMSSM scenarios.
We will present the results of a thorough investigation of certain regions of parameter space, focusing in particular on departures from the well known pure wino scenario: nam
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Presented by Mr. Francesco DIGHERA
on
30 Sep 2015
at
2:00 PM

Session:
Cosmology & Astroparticle Physics

By considering a Quantum Field Theory with time-dependent backgrounds the time-translational symmetry of the Lagrangian may be broken. In my talk I would like to discuss renormalization in curved spacetime using the CTP formalism. In particular, I will show the results for simple diagrams, where explicit calculations are still possible. Connections with the renormalization as an extension of distr
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Presented by Mr. Simone DRESTI
on
1 Oct 2015
at
5:20 PM

Session:
Particle Phenomenology

LHC measurements involve cuts on several observables. Some lead to widely separated energy scales and require resummation. I will present an extension of SCET which enables the resummation of a class of double-differential measurements. Two prototypical application are 1) pp → Z + 0 jets, where the jet veto is imposed through the beam thrust event shape T, and the transverse momentum pT of the Z
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Presented by Lisa ZEUNE
on
30 Sep 2015
at
4:20 PM

Session:
Particle Phenomenology

We propose a framework of supersymmetric standard models that can ameliorate both the SUSY Higgs mass problem and the missing superpartner problem. New vectorlike matter fields couple to the Higgs and provide new loop contributions to its mass. To avoid a Landau pole for new Yukawa couplings, these fields are charged under a new gauge group, which confines and leads to a Hidden Valley-like phenome
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Presented by Dr. Yuichiro NAKAI
on
1 Oct 2015
at
3:00 PM

Session:
Particle Phenomenology

Due to the unknown stop, sbottom and neutralino masses, very different event shapes for squark pair production are imaginable, ranging from unboosted top/bottom quarks and low missing energy to highly boosted top/bottom quarks and large missing energy in the final state. In order to cover a wide range of possible event shapes and consequently stop, sbottom, and neutralino masses, we combined sever
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Presented by Mr. Matthias SCHLAFFER
on
1 Oct 2015
at
4:50 PM

Session:
Strings & Mathematical Physics

Two approaches to heterotic string model building are discussed and compared: first toroidal orbifolds and secondly Calabi-Yau manifolds with line bundle gauge backgrounds.

Presented by Dr. Patrick VAUDREVANGE
on
30 Sep 2015
at
2:25 PM

Session:
Particle Phenomenology

In this talk, I will describe how kinematic distributions in the Higgs to four lepton channel can be used to probe the Standard Model (SM) as well as new physics scenarios. Higher order electroweak corrections make this channel sensitive to anomalous tensor structures in Higgs couplings, making this one of the best direct probes of several types of deviations from the SM including CP violation in
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Presented by Prof. Daniel STOLARSKI
on
1 Oct 2015
at
2:15 PM

Session:
Cosmology & Astroparticle Physics

We consider a fermionic dark matter candidate interacting via a scalar mediator coupled with the Standard Model through a Higgs portal. Motivated by the core-cusp problem, we study dark matter self-interactions which lead us to the region of the parameter space where the scalar mediator is light. We illustrate the relevant features for dark matter abundance, direct search limits and collider const
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Presented by Mr. Ville VASKONEN
on
30 Sep 2015
at
3:00 PM

Session:
Particle Phenomenology

Two-loop calculations with non-trivial renormalization are necessary for the determination of high-precision theory predictions of experimentally well-known quantities. A famous example is the mass of a Higgs-like particle which has been measured at the LHC with a precision at the sub-percent level. A possible interpretation of this particle is given by the Minimal Supersymmetric Standard Model (M
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Presented by Dr. Sebastian PAßEHR
on
1 Oct 2015
at
2:30 PM

We propose a focus point gauge mediation model based on the product group unification (PGU), which solves the double-triplet splitting problem of the Higgs multiplets. In the focus point gauge mediation, the electroweak symmetry breaking scale can be naturally explained even for multi-TeV stops. It is known that the focus point behavior appears if a ratio of the number of SU(2) doublet messengers
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Presented by Dr. Norimi YOKOZAKI
on
1 Oct 2015
at
4:50 PM

First I will give a short comparison of topological defects and topological solitons for various space dimensions (D=1,2,3).
Then I will discuss properties of 2-dimensional solitons for
U(1) gauged easy-axis Heisenberg antiferromagnet, compare these
solitons both with 2D Nielsen-Olesen strings in the Abelian Higgs model and with 2D Belavin-Polyakov solitons in isotropic antiferromagnet model -
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Presented by Dr. Igor BOGOLUBSKY
on
30 Sep 2015
at
5:20 PM

Recently, a model with SO(10) symmetry and bulk flux in 6d was constructed. Anomalies can be canceled and the flux leads to interesting features. Notably, a U(1) flux breaks supersymmetry at a high scale in the matter sector while leaving it intact on gauge and Higgs multiplets. On the other hand, the flux creates a multiplicity for the matter fields while protecting them from symmetry breaking by
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Presented by Mr. Julian SCHWEIZER
on
1 Oct 2015
at
5:20 PM

Session:
Cosmology & Astroparticle Physics

Sterile neutrinos in the keV range are among the most promising
candidates for dark matter. We investigate in detail a model that
extends the Standard Model by a scalar singlet S and sterile
neutrinos N_i.
The scalar couples to the Standard Model via a Higgs portal
coupling, the size of which determines whether or not the scalar
singlet S enters thermal equilibrium in the early Universe. Ste
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Presented by Mr. Maximilian TOTZAUER
on
1 Oct 2015
at
2:15 PM

Session:
Particle Phenomenology

A number of LHC resonance search channels display an excess in the invariant mass region of 1.8 - 2.0 TeV. Among them is a 3.4 sigma excess in the fully hadronic decay of a pair of Standard Model electroweak gauge bosons, in addition to potential signals in the HW and dijet final states. We present a model-independent cross-section fit to the results of all ATLAS and CMS searches sensitive to thes
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Presented by Mr. Johann BREHMER
on
1 Oct 2015
at
2:00 PM

Session:
Cosmology & Astroparticle Physics

The nuMSM is the Standard Model extended by three right-handed neutrinos with Majorana masses below the electroweak scale. The lightest of them is a candidate of dark matter, which is known as sterile neutrino dark matter. Other two heavier particles with quasi-degenerate masses of O(1) GeV are responsible to explain the masses of ordinary neutrinos and baryon asymmetry of the universe (BAU). I
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Presented by Dr. Shintaro EIJIMA
on
1 Oct 2015
at
3:30 PM

We explore a recent proposal of Cosmological Relaxation, by Graham, Kaplan and Rajendran, for generating a hierarchically small Higgs vacuum expectation value. In particular, we discuss its capacity for solving the electroweak hierarchy problem. To do so, we study the dynamics of the model and determine the relation between the fundamental input parameters and the electroweak vacuum expectation va
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Presented by Dr. Lukas WITKOWSKI
on
1 Oct 2015
at
3:15 PM

The Matrix Element Method (MEM) has proven beneficial to make maximal use of the information available in experimental data. However, so far it has been formulated only in Born approximation.
In this talk we discuss the extension to NLO accuracy. As a prerequisite we present an efficient method to calculate event weights for jet events at NLO accuracy.
As illustration and proof of concept we app
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Presented by Till MARTINI
on
1 Oct 2015
at
4:50 PM

Session:
Strings & Mathematical Physics

We give an overview on all F-theory fibrations with the 16 classical 2D polytopes as the fiber.
These models include Abelian, discrete and quotient symmetries as well as the exact standard model of particle physics that we construct explicitly in four dimensions.

Presented by Paul OEHLMANN
on
30 Sep 2015
at
4:05 PM

Session:
Strings & Mathematical Physics

The topological string theory partition function captures non-trivial invariants of Calabi-Yau threefolds. In general, target space symmetries acting on the cohomology induce an automorphic structure on the free energies. For non-compact geometries with spectral curve of genus one this allowed to re-express the physical constraints in terms of modular forms. The construction, however, relied on a
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Presented by Mr. Thorsten SCHIMANNEK
on
30 Sep 2015
at
4:35 PM

Session:
Particle Phenomenology

We discuss transverse momentum dependent (un)polarized gluon distributions (gluon TMDs) and their proper definitions in the context of factorization theorems. All the gluon TMDs have a scale evolution driven by a universal evolution kernel which is resummed to NNLL. By an explicit NLO calculation of the three gluon TMDs which are matched onto leading twist parton distribution functions (PDFs) we d
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Presented by Tomas KASEMETS
on
1 Oct 2015
at
4:20 PM

Session:
Particle Phenomenology

With increasing statistics at the LHC an important observable of the Higgs-like boson is its transverse momentum distribution.
Its dominant contributions arise at small pT, where large logarithms log(pT/mH) need to be resummed to all orders to obtain a reliable theoretical prediction.
This resummation is conveniently performed in the impact parameter space, which is Fourier conjugate to transve
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Presented by Markus EBERT
on
30 Sep 2015
at
4:05 PM

Session:
Strings & Mathematical Physics

QCD evolution equations in MS-like schemes can be recovered from the same equations in a modified theory, QCD in non-integer d=4−2ϵ dimensions, which enjoys exact scale and conformal invariance at the critical point. Restrictions imposed by the conformal symmetry of the modified theory allow one to obtain complete evolution kernels in integer (physical) dimensions at the given order of perturba
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Presented by Dr. Alexander MANASHOV
on
1 Oct 2015
at
2:25 PM

I present rigorous calculations of the constraints that perturbativity and unitarity apply to dark matter in the well-known portal scenarios. These provide the most stringent upper limit on dark matter mass in the thermal cosmology. I will also discuss the physics of dark matter bound states that can become important when the interactions of dark matter become so strong.

Presented by Dr. William SHEPHERD
on
30 Sep 2015
at
2:30 PM

Session:
Particle Phenomenology

CheckMATE is a framework that allows the user to conveniently test simulated BSM physics events against current LHC data in order to derive exclusion limits. For this purpose, the data runs through a detector simulation and is then processed by a user chosen number of experimental analyses. These analyses determine event predictions of the signal for various kinematic regions of interest that can
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Presented by Mr. Daniel SCHMEIER
on
1 Oct 2015
at
2:45 PM

Session:
Cosmology & Astroparticle Physics

I will discuss the idea to combine singlet inflation and Higgs Portal Dark Matter in such a way that the same particle (a gauge singlet scalar) first drives inflation and later freezes out to become cold dark matter. Considering the implications of the Higgs discovery, limits from LUX and observations by Planck, I will show that large regions of parameter space remain viable but will be fully expl
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Presented by Dr. Felix KAHLHOEFER
on
1 Oct 2015
at
4:35 PM

Session:
Particle Phenomenology

In this work we report on a next-to-leading order calculation of WW + jet production at hadron colliders, with subsequent leptonic decays of the W-bosons included. The calculation of the one-loop contributions is performed using generalized unitarity methods in order to derive analytic expressions for the relevant amplitudes. These amplitudes have been implemented in the parton-level Monte Carlo g
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Presented by Dr. Tania ROBENS
on
30 Sep 2015
at
3:15 PM

Session:
Hertz Lecture

Astrophysics and cosmology require physics beyond the Standard Model to explain the origin of matter and the nature of dark matter, and there are many shortcomings of the Standard Model that also cry out for new physics. However, the LHC has found no solid direct evidence yet of physics beyond the Standard Model. What new physics may be out there, and what are the prospects for discovering it at t
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Presented by John ELLIS
on
30 Sep 2015
at
5:55 PM

Session:
Cosmology & Astroparticle Physics

Both WMAP and PLANCK have hinted at a slight suppression of power in the CMB temperature spectrum at large angular scales. Yet this power loss is usually unaccounted for by models that are claimed to provide a best fit to the data at first order, such as the Starobinsky f(R) model. In a first step, we demonstrate how to obtain a viable observational signature in f(R) theory by explicitly construct
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Presented by Mr. Benedict BROY
on
1 Oct 2015
at
4:20 PM

Apart from naturally explaining their smallness, models in which neutrino masses are generated only at the loop level are particularly interesting as they often contain electrically charged scalar fields. These additional particles contribute in particular to lepton flavour and/or number violating processes, like mu -> e gamma or neutrinoless double beta decay. On the other hand, at LHC new charge
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Presented by Tanja GEIB
on
1 Oct 2015
at
2:00 PM