Conveners
Spin-3D
- Bernard Pire
Spin-3D
- Lech Szymanowski
Spin-3D
- Abhay Deshpande (Stony Brook University)
Spin-3D
- Marco Contalbrigo (Dipartimento di Fisica)
Description
Spin-3D session
Mauro Anselmino
(Torino University and INFN)
07/09/2015, 16:45
Spin and 3-d structure
Oral Presentation
The Transverse Momentum Dependent Partonic Distributions (TMD-PDFs) and Fragmentation Functions (TMD-FFs) should reveal new properties of the 3-dimensional structure of nucleons and of the hadronization process. Many experimental data are now available and much progress has been made in their phenomenological interpretation. A short summary of the situation is presented.
Dr
Dieter Mueller
(University of Cape Town)
07/09/2015, 17:10
Spin and 3-d structure
Oral Presentation
Only a consistent QCD framework for a unique description of Compton scattering and meson production in the deeply virtual regime allows to address generalized parton distributions in a universal manner. Such a framework allows also to bridge experimental measurements and results from lattice simulations on a quantitative level and it can be utilized to address the partonic decomposition of the...
Vladimir Braun
(University of Regensburg)
07/09/2015, 17:35
Spin and 3-d structure
Oral Presentation
I discuss recent theoretical progress in making QCD description of DVCS fully quantitative,
including target mass and finite-t corrections and the calculation of the scale-dependence of generalized parton distributions to the NNLO accuracy.
Kresimir Kumericki
(University of Zagreb)
07/09/2015, 18:00
Spin and 3-d structure
Oral Presentation
It will be shown how the new data on DVCS cross-section and asymmetries
coming from CLAS and Hall A JLab collaborations influence global fits.
Michel GUIDAL
(CNRS)
07/09/2015, 18:25
Spin and 3-d structure
Oral Presentation
Generalized Parton Distributions (GPDs) allow to describe the
structure of the nucleon in a very rich and unprecedented way: they
contain the correlations between the (transverse) position and
(longitudinal) momentum distributions of the partons in the nucleon,
they allow to derive the orbital momentum contribution of partons to
the nucleon's spin, they provide an access to the...
Michael Engelhardt
(New Mexico State University)
08/09/2015, 11:10
Spin and 3-d structure
Oral Presentation
An ongoing program of evaluating TMD observables within
lattice QCD is reviewed, summarizing recent progress with
respect to several challenges faced by such calculations.
These lattice calculations are based on a definition of
TMDs through hadronic matrix elements of quark bilocal
operators containing staple-shaped gauge connections. A
parametrization of the matrix elements in terms of...
Barbara Pasquini
(University of Pavia)
08/09/2015, 11:35
Spin and 3-d structure
Oral Presentation
We review the dispersion analysis of deeply virtual Compton scattering and present a dispersive representation of the D-term form factor for hard exclusive reactions.
We use unsubtracted $t$-channel dispersion relations, where
the $t$-channel unitarity relation is saturated with the contribution of two-pion intermediate states, using the two-pion distributions amplitude for the...
Prof.
simonetta liuti
(university of virginia)
08/09/2015, 12:00
Spin and 3-d structure
Oral Presentation
We discuss the canonical (Ji) and kinetic/mechanical (Jaffe and Manohar) definitions of partonic orbital angular momentum (OAM). It was recently shown by Hatta and Burkardt that the two definitions correspond to the second moment in intrinsic k_T of the same generalized transverse momentum distribution (GTMD), while they differ in their gauge link structure. At the same time, as first observed...
Piet Mulders
(VU/Nikhef)
09/09/2015, 13:45
Spin and 3-d structure
Oral Presentation
For many phenomenological applications involving hadrons in high energy processes the hadronic structure can be taken care of by parton distribution functions (PDFs), in which only the collinear momenta of quarks and gluons are important. In principle the transverse structure, however, provides interesting new phenomenology. Taking into account transverse momenta of partons one works with...
Andrea Bressan
(Universita e INFN, Trieste (IT))
09/09/2015, 14:10
Spin and 3-d structure
Oral Presentation
The CERN COMPASS experiment has a broad physics program focused on the nucleon spin structure and on hadron spectroscopy, using muon and hadron beams. One of the main objectives for the spin program with the muon beam is the measurement of transversity and of transverse spin and momentum effects in semi inclusive deep inelastic scattering.
After o short description of the experiment, an...
Dr
Igor Anikin
(JINR)
09/09/2015, 14:35
Spin and 3-d structure
Oral Presentation
We consider the direct photon production in two hadron collision with one transversely polarized hadron. We find new twist $3$ contributions to the hadron tensor associated with this process. We demonstrate that these new terms, first, play a crucial role
to prove both the QED and QCD gauge invariance and, second,
give the sizeable contribution to the hadron tensor compared to the standard...
Nikolay Kivel
(Helmholtz Institute Mainz)
09/09/2015, 15:00
Spin and 3-d structure
Oral Presentation
Existing data for the electromagnetic proton form factors and for the cross section of the wide angle Compton scattering (WACS)
shows that the hard two-gluon exchange mechanism (collinear factorization) is still not applicable in the
kinematical region where Mandelstam variables $s \sim -t \sim -u$ are about few GeV$^2$.
On the other hand these observables can be described
in...
Dennis Sivers
(Portland Physics Institute)
09/09/2015, 15:25
Spin and 3-d structure
Oral Presentation
Transverse single-spin asymmetries are an important tool in the study of hadronic structure. These asymmetries can be parameterized in terms spin-directed momentum transfers generated by nonperturbative spin-orbit mechanisms in QCD. The target fragmentation region in SIDIS processes provides access to asymmetries such as final-state polarization asymmetries in addition to target spin...
Dr
Charlotte Van Hulse
(University of the Basque Country)
10/09/2015, 13:45
Spin and 3-d structure
Oral Presentation
HERMES has collected a wealth of deep-inelastic scattering (DIS) data using the 27.6 GeV
polarized lepton beam at HERA and various pure gas targets, both unpolarized and
polarized. This allowed for a series of diverse and unique measurements. Among them are measurements
that provide information on the three-dimensional structure of the nucleon both in momentum space and in position...
Cédric Lorcé
(University of Liege)
10/09/2015, 14:10
Spin and 3-d structure
Oral Presentation
The canonical energy-momentum tensor is often considered as a purely academic object because of its gauge dependence. However, it has recently been realized that canonical quantities can in fact be defined in a gauge-invariant way provided that strict locality is abandoned, the non-local aspect being dictacted in high-energy physics by the factorization theorems. Using the general techniques...
Dr
Yoshitaka Hatta
(Kyoto University)
10/09/2015, 14:35
Spin and 3-d structure
Oral Presentation
The Wigner distribution is commonly used to define the phase space distribution of partons inside the nucleon. However, the Wigner distribution does not have a probabilistic interpretation because it is not positive definite. In pursuit of a positive phase space distribution in QCD, I suggest to use the Husimi distribution and discuss its properties.
Christian Weiss
(Jefferson Lab)
10/09/2015, 15:00
Spin and 3-d structure
Oral Presentation
An Electron-Ion Collider would enable next-generation measurements of DIS on light
nuclei (deuteron, 3He, ...) with detection of nucleons and fragments in the nuclear
fragmentation region ("spectator tagging"). Such measurements allow one to control
the nuclear configuration during the high-energy process and could greatly advance
our understanding in several areas of partonic structure...
Hervé MOUTARDE
10/09/2015, 15:25
Spin and 3-d structure
Oral Presentation
In order to learn effectively from measurements of Generalised Parton Distributions (GPDs), it is desirable to compute them using a framework that can potentially connect empirical information with basic features of the Standard Model. We sketch an approach to such computations, based upon a rainbow-ladder (RL) truncation of QCD's Dyson-Schwinger equations and exemplified via the pion's...
