Conveners
Session 2: Theory aspects
- Bakur Parsamyan (AANL, Turin section of INFN and CERN)
- Andrea Simonelli (INFN Roma 1)
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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...
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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...
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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...
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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.
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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...
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