A back-to-back semi-inclusive J/ψ- jet production is a promising process to study gluon transverse momentum distribution (TMD) at the future electron-ion collider. A back-to-back configuration allows a higher transverse momentum for J/\psi We present an extension of a previous work where we studied cos 2φ azimuthal asymmetry within the TMD factorization framework for this process. We present...
In this talk, I present predictions for the unpolarized differential cross-section of J/ψ electroproduction at the Electron-Ion Collider (EIC) in the low transverse momentum region. I also compare with the experimental data for photoproduction at HERA. The calculation was performed at next-to-leading order (NLO) in the hard function and resummed at next-to-next-to-leading logarithmic accuracy...
Extraction of observables sensible to gluon TMDs is one of the main goals of many proposed high-energy experiments. In this talk, I will present results for the production of C-even quarkonium states in proton-proton collisions. The quarkonium formation mechanism is described within the framework of Non-Relativistic QCD (NRQCD). Our computation for the cross sections incorporates the...
We present an extension of the string+3P0 model of hadronization that includes the production and decays of polarized spin-1/2 baryons. The new model predicts: a Collins effect for baryon emission in transversely polarized quark fragmentations, the transverse spin transfer from the quark to the baryon, a baryon transverse polarization with respect to the production plane in unpolarized quark...
Di-hadron fragmentation functions represent an alternative method for extracting the transversity PDF, complementary to the Collins effect.
However, data on unpolarized inclusive cross sections for charged di-hadron production have only become available recently.
In this talk, I will present a new extraction of the unpolarized di-hadron fragmentation functions up to NNLO accuracy, carried...
Future planned lepton colliders, both in the circular and linear configurations, can effectively work as virtual and quasi-real photon-photon colliders and are expected to stimulate an intense physics program in the next few years. In this paper, we suggest to consider photon-photon scattering as a useful source of information on transverse momentum dependent fragmentation functions (TMD FFs),...
The COMPASS experiment at CERN has played a pivotal role in advancing our understanding of the spin structure and dynamics of the nucleon, as well as the internal landscape of hadrons. With its versatile muon and hadron beams, COMPASS has delivered key insights into transverse momentum-dependent distributions (TMDs), generalized parton distributions (GPDs), and the nucleon’s spin puzzle. As we...
A polarized gaseous target, operated in combination with the high-energy and high-intensity LHC beams, has the potential to open new physics frontiers and to deepen our understanding of the strong interaction in the non-perturbative regime of QCD. Specifically, the LHCspin project aims to perform spin-physics studies in high-energy polarized fixed-target collisions using the LHCb detector....
We present next-to-leading order QCD corrections for the cross sections of
$\ell p^\uparrow\to (h\,\mathrm{or}\,jet)X$ with transversely polarized initial protons.
These cross sections are known to be power-suppressed in QCD
and probe twist-3 parton correlation functions in the proton. Our calculation exhibits the full complexity of a
perturbative QCD analysis beyond leading power,...
We explore the quark and the gluon Sivers functions in dijet production at the EIC. Our analysis includes a comprehensive investigation of the sin($\phi_S - \phi_r$) modulated cross-sections for both quark and gluon channels. Furthermore, we state the possibility of re-defining the resummation method, altering the treatment of large logarithmic corrections. We also test different models for...
In this talk I present a QED-based analog of the Sivers effect in QCD. In particular, Compton scattering off an ionized Helium-4 target is used as a process to access the Sivers effect for the electron in the atomic target.
To account for the motion of the bound electron in the Helium target, hydrogen-like wave functions in momentum space are employed.
Both the unpolarized TMD distribution...
We consider the Energy-Energy Correlation (EEC) in electron-positron
annihilation into hadrons at high energies, in the back-to-back (two-jet) region. We propose a simple formalism to consistently incorporate
heavy-quark mass effects in the QCD Sudakov form factor, which governs the resummation of large infrared logarithms. We also briefly discuss the extension of our results to the...
Bringing collider-based QCD observables to the observed astrophysical excess of antiprotons in cosmic rays appears to be a useful cross-disciplinary venture. Astrophysical observations require a precise calculation of the cross sections for direct proton-proton to antiproton production vs. indirect production (in which the protons first produce an antineutron that decays down to an antiproton...
In this talk I will review and discuss the main results obtained from our collaboration regarding the study and calculations of various parton distributions for light nuclei including 2H, 3H, 3H and 4He. In particular, I will review the evaluation of the nuclear EMC effect 3H, 3H and 4He where the nuclear structure functions incorporated in the EMC ratio have been calculated within the...
The phenomenological extraction of Transverse Momentum Dependent (TMD) parton distributions is key to probing the three-dimensional structure of hadrons and gaining deeper insights into the strong force and Quantum Chromodynamics (QCD). While TMDs are rigorously defined through QCD operators, their extraction from experimental data is complicated by the dominance of non-perturbative effects at...
In this talk, we present a description at the highest available perturbative accuracy of the complete transverse-momentum $q_T$ spectrum in low-invariant-mass Drell–Yan production, with special attention to the challenging high-$q_T$ region.
I will present a new, refined, version of the "affinity" tool, based on an Monte Carlo event-by-event mapping of the SIDIS kinematic regions. Affinity is a diagnostic tool that allows us to quantify our level of confidence in the application of the appropriate factorization theorem (TMD or collinear) in each kinematic bin (x,Q^2,z,P_T) in which the final hadron is produced in SIDIS processes.
We present the framework for obtaining precise predictions for the transverse momentum of hadrons with respect to the thrust axis in ep collisions. This will enable a precise extraction of TMD parton distributions. To this end, we make use of the derived factorization theorems within Soft Collinear Effective Theory, and calculate and renormalize the present functions. That is, the thrust-soft,...
I will show recent progresses in the treatment of TMD in the large-x limit and in the leading-TMD approximations. These treatments of the TMD are particularly useful when perturbative information is still not precise enough and allow to make predictions on higher-twist TMD, TMD moments, and angularities.
Fragmentation functions as well as parton distributions are fundamental non-perturbative objects that allow knowledge obtained from different processes to be used for the understanding of other processes through QCD factorization theorems. They also serve as a test bed of the theoretical framework. Recent results on hadronziation from several key processes: hadron-hadron interaction, e+e-...
Fragmentation functions play a crucial role in describing the hadronization process.
We report the measurements of normalized differential cross sections of inclusive pi0, Ks, and eta production as a function of hadron momentum at six energy points with q^2 transfer from 5 to 13 GeV^2 at BESIII. In addition, new recent results of single inclusive charged pions and kaons at center of mass...
In this talk, we present some recent updates on the TMD fragmentation functions (FFs), namely the unpolarized and the Collins FFs. The impact of $A_N$ data measured in inclusive processes is estimated through an extended version of the Bayesian reweighting method, and the universality properties of these functions are tested through estimates of the Collins asimmetry for $\pi$-jet production...
