-
Dr Bakur Parsamyan (AANL, Turin section of INFN and CERN)21/05/2026, 14:30
-
Valentin Moos (NYCU)21/05/2026, 14:40
We present an extraction for the unpolarised transverse momentum dependent (TMD) parton distribution functions (PDFs) for the quarks in the pion from measurements of the Drell-Yan process.
The results are obtained from a fit of the non-perturbative part of the TMDPDFs in the framework of TMD factorisation
and rely on the non-perturbative input for the collinear PDFs.As the data is...
Go to contribution page -
Mr Lorenzo Rossi (University of Milan & INFN)21/05/2026, 15:10
In this talk, we extend the study of low-invariant-mass Drell–Yan production over the full transverse-momentum spectrum, combining transverse-momentum resummation at small $q_T$ with fixed-order perturbative calculations at large $q_T$, together with a phenomenological description of non-perturbative effects.
Go to contribution page
We first consider proton–proton scattering as a benchmark to validate the approach.... -
Carlo Flore (Università di Cagliari & INFN)21/05/2026, 15:40
In this talk, we present new results for double quarkonium production in (un)polarized hadronic collisions at fixed-target experiments. Our approach incorporates the transverse momentum dependent factorization in combination with the Color-Singlet Model. We present new analytical expressions for the angular structure of the cross section for the $q \bar q$-induced channel, highlighting its...
Go to contribution page -
Patrick Barry (Argonne National Lab)21/05/2026, 16:30
The pion and kaon are the pseudo-Goldstone bosons associated with chiral symmetry breaking as well as the lightest hadrons made up of quarks and gluons. Studying their structures allows us to understand more deeply the dynamics of QCD and emergent phenomena. Experimentally, the meson-induced Drell-Yan process provides sensitivity for the valence distributions at large momentum fraction, while...
Go to contribution page -
Aurore Courtoy21/05/2026, 17:00
In light of recent progress on both the experimental and lattice-QCD sides, our understanding of the pion’s structure has evolved. Phenomenological, or global, QCD analyses play a crucial role in establishing a bridge between experimental data, theoretical predictions, and lattice-QCD studies. I will present recent efforts in the determination of the distribution of partons in the pion, with...
Go to contribution page -
Andrea Simonelli (INFN Roma 1)22/05/2026, 10:00
Transverse Momentum Dependent (TMD) parton distribution functions are rigorously defined QCD operators; however, their extraction remains challenging due to the dominance of non-perturbative effects at low energy scales. As a result, the role of phenomenological modeling is difficult to systematically control and may lead to potential misinterpretations of the information encoded in...
Go to contribution page -
Matteo Cerutti (CEA Paris-Saclay)22/05/2026, 10:30
In this talk, I will present a phenomenological study aimed at assessing the impact of phenomenological choices in fits of Transverse Momentum Distributions (TMDs). In particular, I will focus on the so-called $b_*$ prescription, which is introduced in the standard Collins-Soper-Sterman (CSS) formalism to avoid the Landau pole. Using low invariant-mass Drell-Yan data, we observe that different...
Go to contribution page -
Marco Zaccheddu (Jefferson Lab)22/05/2026, 11:20
We present a new nonparametric framework for the Bayesian inference of TMD parton distributions. By discretizing the impact parameter space into "pixels", we eliminate the biases of traditional functional forms. To sample the complex high-dimensional posterior, we employ a hybrid Normalizing Flow-driven Metropolis-Hastings algorithm. Using Singular Value Decomposition (SVD), we formally...
Go to contribution page -
Filippo Delcarro (Università di Pavia (IT))22/05/2026, 11:50
We discuss the impact of different datasets on the extraction of the partonic Sivers function, with a particular focus on COMPASS SIDIS and DY measurements.
Go to contribution page -
Óscar del Río García (Complutense University of Madrid)22/05/2026, 12:20
I will discuss the large-x behaviour of transverse momentum dependent distributions (TMDs) through the resummation of singular contributions in this regime to their collinear matching coefficients. The resummation is performed directly at the level of TMDs, preserving the process-independent structure of the formalism and allowing a unified treatment of different distributions relevant for...
Go to contribution page -
Alessia Bongallino (University of the Basque Country UPV/EHU)22/05/2026, 14:30
The helicity parton distribution function plays a crucial role in better understanding the quark and gluon spin structure of the proton. We study the transverse momentum dependence of the quark helicity distribution by analysing experimental data on semi-inclusive deep inelastic scattering off longitudinally polarised targets provided by the HERMES Collaboration. The fit is performed at...
Go to contribution page -
Ignacio Borsa (Tübingen University)22/05/2026, 15:00
The study of the internal spin structure of the proton in terms of the contributions from quarks, anti-quarks and gluons, is a key focus of modern particle physics. These contributions can be described in terms of the longitudinally polarized parton distribution functions (pPDFs) or helicity PDFs, which are probed in high-energy scattering processes involving polarized nucleons.
Go to contribution page
In this talk... -
Dr Bakur Parsamyan (AANL, Turin section of INFN and CERN)22/05/2026, 15:50
The longitudinal spin structure of the proton is studied with the COMPASS experiment using SIDIS data collected with a longitudinally polarized NH$3$ target and positive muon beams of 160 GeV/$c$ in 2007 and 200 GeV/$c$ in 2011. The analysis focuses on the double-spin asymmetry $A{LL}$, providing access to the spin-dependent structure function $g_1$, together with azimuthal asymmetries...
Go to contribution page -
Harut Avakian (Jefferson Lab)22/05/2026, 16:20
We present recent CLAS12 studies of target longitudinal-spin effects in semi-inclusive deep-inelastic scattering. The results provide new constraints on spin-dependent TMDs and the longitudinal spin structure of the nucleon.
Go to contribution page -
Gunar Schnell22/05/2026, 16:50
In this contribution, we will recall the analysis details leading to the publication of the HERMES longitudinal-spin asymmetries, with a focus on A_LL in semi-inclusive DIS.
Go to contribution page -
Dr Lorenzo Rossi (University of Milan & INFN)25/05/2026, 14:00
-
Andrea Simonelli (INFN Roma 1)25/05/2026, 14:20
-
Alessia Bongallino (University of the Basque Country UPV/EHU)25/05/2026, 14:40
-
25/05/2026, 15:00
-
ALESSIA BONGALLINO (Universidad del PaÍs Vasco (UPV/EHU))
-
-
Mr Lorenzo Rossi (University of Milan & INFN)
Choose timezone
Your profile timezone: