Conveners
WG6 Spin Physics
- Salvatore Fazio (Brookhaven National Laboratory)
- Emanuele Roberto Nocera (Rudolf Peierls Centre for Theoretical Physics University of Oxford)
- Silvia Pisano (Laboratori Nazionali di Frascati - INFN)
- Erin Seder (CEA Saclay DSM/IRFU/SPhN/LSN)
WG6 Spin Physics
- Silvia Pisano (Laboratori Nazionali di Frascati - INFN)
- Emanuele Roberto Nocera (Rudolf Peierls Centre for Theoretical Physics University of Oxford)
- Salvatore Fazio (Brookhaven National Laboratory)
- Erin Seder (CEA Saclay DSM/IRFU/SPhN/LSN)
WG6 Spin Physics
- Emanuele Roberto Nocera (Rudolf Peierls Centre for Theoretical Physics University of Oxford)
- Silvia Pisano (Laboratori Nazionali di Frascati - INFN)
- Erin Seder (CEA Saclay DSM/IRFU/SPhN/LSN)
- Salvatore Fazio (Brookhaven National Laboratory)
WG6 Spin Physics
- Silvia Pisano (Laboratori Nazionali di Frascati - INFN)
- Erin Seder (CEA Saclay DSM/IRFU/SPhN/LSN)
- Emanuele Roberto Nocera (Rudolf Peierls Centre for Theoretical Physics University of Oxford)
- Salvatore Fazio (Brookhaven National Laboratory)
WG6 Spin Physics
- Silvia Pisano (Laboratori Nazionali di Frascati - INFN)
- Salvatore Fazio (Brookhaven National Laboratory)
- Erin Seder (CEA Saclay DSM/IRFU/SPhN/LSN)
- Emanuele Roberto Nocera (Rudolf Peierls Centre for Theoretical Physics University of Oxford)
WG6 Spin Physics
- Silvia Pisano (Laboratori Nazionali di Frascati - INFN)
- Erin Seder (CEA Saclay DSM/IRFU/SPhN/LSN)
- Emanuele Roberto Nocera (Rudolf Peierls Centre for Theoretical Physics University of Oxford)
- Salvatore Fazio (Brookhaven National Laboratory)
WG6 Spin Physics
- Erin Seder (CEA Saclay DSM/IRFU/SPhN/LSN)
- Silvia Pisano (Laboratori Nazionali di Frascati - INFN)
- Salvatore Fazio (Brookhaven National Laboratory)
- Emanuele Roberto Nocera (Rudolf Peierls Centre for Theoretical Physics University of Oxford)
WG6 Spin Physics
- Erin Seder (CEA Saclay DSM/IRFU/SPhN/LSN)
- Emanuele Roberto Nocera (Rudolf Peierls Centre for Theoretical Physics University of Oxford)
- Silvia Pisano (Laboratori Nazionali di Frascati - INFN)
- Salvatore Fazio (Brookhaven National Laboratory)
Piet Mulders
(Nikhef and VU, Amsterdam)
12/04/2016, 09:00
Spin Physics
We investigate the gluon transverse momentum dependent correlators as Fourier transform of matrix elements of nonlocal operator combinations. At the operator level these correlators include both field strength operators and gauge links bridging the nonlocality. In contrast to the collinear PDFs, the gauge links are no longer unique for transverse momentum dependent PDFs (TMDs) and also Wilson...
Dr
Mariaelena Boglione
(University of Turin (Italy))
12/04/2016, 09:30
Spin Physics
I will address the study of semi-inclusive deep inelastic scattering
cross sections as functions of the transverse momentum, $q_T$. Soft gluon
resummation is performed using the original Collins-Soper-Sterman (CSS)
formalism or, equivalently, the improved Transverse Momentum Dependent
(TMD) framework.
The focus of this talk is the matching between the region where fixed
order...
Dr
Shinsuke Yoshida
(Central China Normal University)
12/04/2016, 09:50
Spin Physics
In this talk, we discuss the new hard pole contribution to the transverse-momentum-weighted single-transverse spin asymmetry in semi-inclusive deep inelastic scattering. We perform the complete next-to-leading order calculation of the $P_{h\perp}$-weighted cross section and show that the new hard pole contribution is required in order to obtain the complete evolution equation for the...
Prof.
Wim Cosyn
(Ghent University)
12/04/2016, 10:10
Spin Physics
We cover the general structure of the SIDIS cross section with a polarized beam and spin-1 target. The cross section is characterized by 41 structure functions of which 23 are unique to the spin-1 target case. Next, we study a specific example, namely DIS off a polarized deuteron with a slow detected nucleon in the final state ("tagged spectator DIS"). The reaction is studied in the impulse...
Dr
Kiyoshi Tanida
(Japan Atomic Energy Agency)
12/04/2016, 11:00
Spin Physics
In high-energy hadron collisions, most energy goes into the forward region.
However, particle production mechanisms in the forward region are not well
understood as perturbative QCD is not applicable at small momentum transfers.
We study single spin asymmetries (A_N) of forward neutron production
in the PHENIX experiment using a transversely polarized proton beam.
In 2015, we took data...
Mr
Christopher Dilks
(Pennsylvania State University)
12/04/2016, 11:20
Spin Physics
In 2015 the first collisions between polarized protons and nuclei occurred at the Relativistic Heavy Ion Collider (RHIC), at a center-of-mass energy of $\sqrt{s_{NN}}=200$ GeV. Comparisons between spin asymmetries and cross-sections in $p+p$ production to those in $p+A$ production provide insight into nuclear structure, namely nuclear modification factors, nuclear dependence of spin...
Dr
Salvatore Fazio
(Brookhaven National Laboratory)
12/04/2016, 11:40
Spin Physics
Accessing the Sivers TMD function in proton+proton collisions through the measurement of transverse single
spin asymmetries (TSSAs) in Drell-Yan and weak boson production is an effective path to test the fundamental
QCD prediction of the non-universality of the Sivers function. Furthermore, it provides
data to study the spin-flavor structure of valence and sea quarks inside the proton and...
Harut Avagyan
(JLab)
12/04/2016, 12:00
Spin Physics
The Deep Inelastic Scattering (DIS) proved to be a great tool in testing
the theory of strong interactions, which was a major focus in last decades.
Semi-Inclusive DIS (SIDIS), with detection of an additional hadron, allowed first studies of 3D structure of the nucleon, moving the main focus from testing the QCD to understanding of strong interactions and quark-gluon dynamics
to address a...
Harut Avagyan
(JLab)
12/04/2016, 12:20
Spin Physics
Studies of spin-azimuthal asymmetries in semi-inclusive production of hadrons have been widely recognized as key objectives of the JLab 12 GeV upgrade and a driving force behind the construction of the Electron Ion Collider. Various assumptions involved in preliminary extraction of underlying transverse momentum dependent partonic distributions (TMDs) from available data, have yet to allow...
Ms
Charlotte Van Hulse
(University of the Basque Country)
12/04/2016, 12:40
Spin Physics
Semi-inclusive deep-inelastic lepton-nucleon scattering provides a powerful tool for unraveling the multi-dimensional internal spin-momentum structure of the nucleon. In particular, the dependence on transverse momentum of the produced hadron allows the study of numerous novel effects like the Sivers and Collins mechanism. The HERMES experiment, with its versatile gas target internal to the...
Dr
Andrea Bressan
(University of Trieste and Trieste Division of INFN)
12/04/2016, 14:30
Spin Physics
COMPASS is a fixed target experiment in operation at CERN since 2002 with a wide physics programme. By using either muon or hadron beams, both the study of the spin structure of the nucleon and the search of exotic states in hadron spectroscopy are performed.
An important part of this programme is the study of transverse spin and momentum dependent parton distribution and fragmentation...
Márcia Quaresma
(LIP - Lisbon)
12/04/2016, 15:00
Spin Physics
The COMPASS experiment at CERN has been contributing to the knowledge on the nucleon structure, and its description in terms of the Transverse Momentum Dependent Parton Distribution Functions (TMD PDFs), accessed through the SIDIS process. In 2014/2015 the data taking was dedicated to the polarised Drell-Yan (DY) measurement with a negative pion beam and a transversely polarised proton target,...
Mr
Adam Szabelski
(University of Trieste)
12/04/2016, 15:20
Spin Physics
The Sivers effect describes the correlation between the spin of the nucleon and the orbital motion of partons. For gluons it has been measured at COMPASS via $J/\Psi$ production and via high-$p_T$ hadron pair production in Semi-Inclusive Deep Inelastic Scattering of a 160 GeV/$c$ muon beam off transversely polarised proton and deuteron targets by determining the amplitude of the modulation...
Prof.
Yuji Koike
(Department of Physics, Niigata University)
12/04/2016, 16:30
Spin Physics
We derive a complete set of relations among twist-3 distribution and fragmentation functions based on the QCD equation-of-motion and identities among nonlocal operators which fully incorporate the constraints from Lorentz invariance. We show that the dynamical twist-3 functions constitute a complete set of twist-3 functions and other types of twist-3 functions can be expressed in terms of the...
Dr
Shinsuke Yoshida
(Central China Normal University)
12/04/2016, 16:50
Spin Physics
We discuss the twist-3 contributions to the double-spin asymmetry A_{LT} for light hadron production in collisions between transversely and longitudinally polarized protons. So far only twist-3 effect in the transversely polarized proton have been studied for A_{LT}. In this talk, we discuss other possible twist-3 contributions in order to derive the complete leading-order cross section...
Mr
Kenta Yabe
(Niigata University)
12/04/2016, 17:10
Spin Physics
We study the transverse porlarization of hyperons produced in the high-energy unporlarized proton-proton collision in the framework of the collinear factorization. This phenomenon is one of the twist-3 observables and twist-3 distribution and fragmentation functions contribute. In this work, we focus on the former contribution and derive the LO complete cross-section. For the soft-gluon-pole...
Dr
Erin Seder
(CEA Saclay DSM/IRFU/SPhN/LSN)
12/04/2016, 17:30
Spin Physics
The latest measurements of charged pion, kaon, and unidentified hadron multiplicities in semi-inclusive deep-inelastic scattering from the COMPASS experiment at CERN are presented. The data were collected using a 160 GeV muon beam incident on an isoscalar 6LiD target. The large statistics collected cover a wide kinematic range in photon virtuality: 1 < Q2 < 50 (GeV/c)2, relative virtual-photon...
Ms
Charlotte Van Hulse
(University of the Basque Country)
12/04/2016, 17:50
Spin Physics
Inclusive cross sections and azimuthal asymmetries were extracted from
e+e− annihilation data collected with the Belle detector. These data were
taken at the KEKB e+e− collider at a center-of-mass energy of around
sqrt(s) = 10.58 GeV. The cross sections for single-hadron and hadron-pair production provide very clean information on the spin-independent fragmentation functions, which...
Dr
J. Osvaldo Gonzalez Hernandez
(Old Dominion University)
12/04/2016, 18:10
Spin Physics
New investigations on the Collins functions have been made possible by recent e+ e− annihilation data released by the BaBar Collaboration. These data allow to directly infer the transverse momentum dependence of the Collins function for pions and, for the first time, attempt extractions of the kaon Collins function. In this talk, I will discuss our recent results of the analysis of these and...
nobuo sato
(jefferson lab)
13/04/2016, 09:50
Spin Physics
We present a comprehensive new global QCD analysis of polarized inclusive deep-inelastic scattering, including the latest high-precision data on longitudinal and transverse polarization asymmetries from Jefferson Lab and elsewhere. The analysis is performed using a new iterative Monte Carlo fitting technique which generates stable fits to polarized parton distribution functions (PDFs) with...
Ms
Claudia Uebler
(University of Regensburg)
13/04/2016, 10:10
Spin Physics
We study the cross section for the photoproduction process gamma N -> h X where the incident photon and nucleon are longitudinally polarized and a hadron h is observed at high transverse momentum. Specifically, we address the "direct" part of the cross section, for which the photon interacts in a pointlike way. For this contribution we perform an all-order resummation of logarithmic threshold...
Mr
Malte Wilfert
(Johannes-Gutenberg-Universitaet Mainz)
13/04/2016, 11:00
Spin Physics
The COMPASS experiment at CERN SPS has taken data with a polarised muon beam scattering off a polarised LiD target from 2002-2004. The same measurement was also performed in 2006 increasing the statistics by roughly a factor of two.
The new results from 2006 data on the longitudinal double spin asymmetry A_1^d on the spin dependent structure function g_1^d will be shown and compared to the...
Ana Sofia Nunes
(LIP-Lisbon)
13/04/2016, 11:20
Spin Physics
The longitudinal double spin asymmetries A1p and the spin dependent structure function of the proton g1p were extracted from COMPASS data in the region of low x and low Q2. The data were taken on 2007 and 2011 from scattering of polarised muons off polarised protons, resulting in a sample that is...
Ralf Seidl
(RIKEN)
13/04/2016, 11:40
Spin Physics
One of the main goals of the RHIC spin program is the determination of the gluon helicity contribution to the proton spin. This can be accessed by measuring double spin asymmetries ($A_{LL}$) of pion production at mid-rapidity in longitudinally polarized proton collisions with the PHENIX experiment. The ordering of the asymmetries with the charge of the final state pions can in addition...
Suvarna Ramachandran
(STAR Collaboration, University of Kentucky)
13/04/2016, 12:00
Spin Physics
The production of jets in polarized proton collisions at STAR is dominated by quark-gluon and gluon-gluon scattering processes. The dijet longitudinal double-spin asymmetry (A_LL) is sensitive to the polarized parton distributions and may be used to extract information about the gluon helicity contribution (ΔG) to the spin of the proton. Previous STAR jet measurements at √s = 200 GeV show...
Prof.
Bernd Surrow
(Temple University)
13/04/2016, 12:20
Spin Physics
The STAR experiment at RHIC has provided significant contributions to our understanding of the structure of the proton. The STAR experiment is well equipped to measure $W^\pm \rightarrow e^\pm + \nu$ in $\sqrt{s}=510$ GeV longitudinally polarized $p+p$ collisions at mid-rapidity ($|\eta|<1$). W single-spin asymmetries, $A_L$, measured as a function of decay positron (electron) pseudo-rapidity...
Silvia Niccolai
(IPN Orsay)
13/04/2016, 16:30
Spin Physics
Generalized Parton Distributions (GPDs) are nowadays the object of an intense effort of research, in the perspective of understanding nucleon structure. They describe the correlations between the longitudinal momentum and the transverse spatial position of the partons inside the nucleon and they can give access to the contribution of the orbital momentum of the quarks to the nucleon spin....
Kyungseon Joo
(University of Connecticut, Storrs, CT 06269, USA)
13/04/2016, 17:00
Spin Physics
An extensive experimental program with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab has been under way to study the 3-dimensional structure of the nucleon through investigating Generalized Parton Distributions (GPDs) by measuring hard exclusive processes such as deeply virtual Compton scattering (DVCS) and deeply virtual meson production (DVMP). The GPDs provide a route to...
Mr
Philipp Jörg
(University of Freiburg)
13/04/2016, 17:20
Spin Physics
A major part of the COMPASS-II program will be dedicated to the investigation of generalized parton distributions (GPDs)
and transverse momentum dependent parton distributions (TMDs), which aim for the most complete
description of the partonic structure of the nucleon.
GPDs are experimentally accessible via lepton-induced exclusive reactions, in particular
the Deeply Virtual Compton...
Sergey Manaenkov
(B.P. Konstantinov Petersburg Nuclear Physics Institute - PNPI)
13/04/2016, 17:40
Spin Physics
The HERMES experiment has extensively studied exclusive meson production in deep-inelastic scattering of the 27.6 GeV electron/positron beam of HERA by various gaseous targets internal to the storage ring. Recent results on exclusive omega production are presented: spin-density matrix elements using unpolarized and longitudinally polarized leptons and unpolarized hydrogen and deuterium...
Dieter Mueller
(Ruder Boskovic Institute, Zagreb, Croatia)
14/04/2016, 11:00
Spin Physics
A mini review on the phenomenology of exclusive measurements in the deeply virtual region is presented, where some emphasis is given to deeply virtual Compton scattering measurements from JLAB and the first access of the 2$\pi$ generalized distribution amplitude from Belle measurements. Furthermore, new perturbative next-to-leading order results are reported.
Prof.
Gary Goldstein
(Tufts University)
14/04/2016, 11:30
Spin Physics
Spin and transverse momentum dependent parton distributions - GPDs, TMDs and GTMDs - are at the interface between the non-perturbative regime of QCD hadron structure and observable quantities. The distributions appear as linear superpositions and convolutions within helicity amplitudes for parton-nucleon scattering processes, which, in turn, occur in amplitudes for leptoproduction processes....
Renaud Boussarie
(CNRS, Univ. Paris-Sud, 91405 Orsay, France)
14/04/2016, 11:50
Spin Physics
Transversity GPDs have yet to be experimentally unraveled. We propose to probe them by studying photoproduction of a rho meson and a photon and we give a feasibility study for this process to be measured at JLAB or by COMPASS.
Mr
Christian Wiese
(John von Neumann Institute for Computing (NIC), DESY, Platanenallee 6, 15738 Zeuthen, Germany)
14/04/2016, 12:10
Spin Physics
The exact decomposition of the proton spin has been a much debated topic, on the experimental as well as the theoretical side. In this talk we would like to report on recent non-perturbative results and ongoing efforts to explore the proton spin from lattice QCD. We present results for several form factors from gauge field ensembles that feature a physical value of the pion mass. These form...
