Conveners
Thursday: morning / 1
- Lorenzo Rossi (Istituto Nazionale di Fisica Nucleare)
Thursday: morning / 2
- Swagato Mukherjee (Assistant Physicist)
Thursday: afternoon / 1
- Andrea Signori (Istituto Nazionale di Fisica Nucleare)
Thursday: afternoon / 2
- Filippo Delcarro (Istituto Nazionale di Fisica Nucleare)
In this talk, I will revisit the evolution of generalised parton distributions (GPDs) at leading order in the strong coupling constant $\alpha_s$ for all of the twist-2 quark and gluon operators. I will present a rederivation of the one-loop evolution kernels, expressing them in a form suitable for implementation, and check analytically that some basic properties, such as DGLAP/ERBL limits and...
I will present the limits and complementarity of GPD phenomenology using simultaneously lattice QCD, experimental data and theoretical models. I will point out how none of the three can convey a satisfactory picture alone as of now, but explore collectively complementary information. I will stress the crucial role of evolution in the uncertainties on the lattice, the modeling of GPDs at small...
In this presentation, we provide an overview of Generalized Transverse Momentum Dependent Distributions (GTMDs) of hadrons, recognized as the most comprehensive two-parton correlation functions. We discuss recent advancements in this field, emphasizing the state-of-the-art observables for these quantities and their significant implications for the field of spin physics.
In this talk, we present the latest results by the MAP Collaboration about the extraction of unpolarized quark Transverse-Momentum-Dependent Distributions (TMD PDFs) and Fragmentation Functions (TMD FFs) from global fits of Drell-Yan and Semi-Inclusive Deep-Inelastic Scattering (SIDIS) data sets. In particular, we discuss the impact of the introduction of flavour dependence in the...
Pions and kaons play an important role in QCD, as they are the pseudo-Goldstone bosons of chiral symmetry breaking while also being confined systems of quarks and gluons. Recent works on pion structures through the JAM framework introduce both Drell-Yan (DY) and leading neutron (LN) electroproduction observables to constrain parton distribution functions (PDFs) in the pion. By making use of...
We present a first practical implementation of a recently proposed hadron structure oriented (HSO) approach to TMD phenomenology applied to Drell-Yan like processes, including lepton pair production at moderate $Q^2$ and $Z^0$ boson production. We emphasize the HSO's preservation of a basic TMD parton-model-like framework even while accounting for full TMD factorization and evolution. We argue...
After recalling the latest extractions of the $\Lambda$ polarizing fragmentation functions within a TMD approach from fits to $e^+e^-$ data, I will present theoretical estimates for the spontaneous transverse polarization of $\Lambda$ hyperons produced in unpolarized $pp$ collisions inside a jet. For the latter, transverse momentum effects are included only in the fragmentation mechanism....
I will report on recent QCD global analyses of transverse single-spin asymmetries involving two different approaches: transverse momentum dependent (TMD)/collinear twist-3 (CT3) observables involving single-hadron FFs, and twist-2 collinear observables involving dihadron fragmentation functions (DiFFs). A byproduct of these studies is the extraction of the transversity PDFs and calculation of...
The string+3P0 model of hadronization has been recently applied to the fragmentation of a string stretched between a quark-antiquark pair with correlated spin states. The pair is assumed to be created in e+e- annihilation via the exchange of a virtual photon. To perform simulations of e+e- events, the model has been implemented in the Pythia Monte Carlo event generator by extending the...
The Drell-Yan process is essential for the determination of the collinear and transverse momentum dependent (TMD) parton distribution function. For a nuclear target, in addition to the non-perturbative parton structure that is intrinsically different from that of a free nucleon, there are dynamical nuclear matter effects that modify the TMD cross section in proton-nucleus ($pA$) collisions....
I will present a calculation of perturbative $T$-odd contributions to the lepton angular distribution in the Drell-Yan process. The talk is based on work done with Valery Lyubovitskij, Werner Vogelsang, and Alexey Zhevlakov; the corresponding pre-print is available under $\texttt{arXiv:2403.18741}$.
Using collinear factorization, we worked at the first order in QCD perturbation theory...
I will present a novel semi-analytical method for parton evolution. The talk is based on work done with co-authors Oliver Schüle and Fabian Wunder, the corresponding preprint is $\texttt{arXiv:2404.18667}$.
The presented method is based on constructing a family of analytic functions spanning $x$-space which is closed under the considered evolution equation. Using these functions as a basis,...
