Conveners
Wednesday: morning / 1
- Umberto D'Alesio (Istituto Nazionale di Fisica Nucleare)
Wednesday: morning / 2
- Jean-Philippe Lansberg (IJCLab- Paris-Saclay U. - CNRS)
Wednesday: afternoon / 1
- Mariaelena Boglione (Istituto Nazionale di Fisica Nucleare)
Wednesday: afternoon / 2
- Matteo Cerutti (Hampton University and Jefferson Lab)
I discuss MAPPDFpol1.0, a new determination of the helicity-dependent parton distribution functions (PDFs) of the proton from a set of longitudinally polarised inclusive and semi-inclusive deep-inelastic scattering data. The determination includes, for the first time, next-to-next-to-leading order QCD corrections to both processes, and is carried out in a framework that combines a...
It is well known that the axial current exhibits the so-called chiral anomaly. The role of this anomaly in the context of the spin sum rule of the nucleon has been intensely discussed soon after the experimental discovery of the spin crisis in the late 1980s. While this field was largely dormant over the last decades, recent work has revived interest in this area. We will discuss...
Recently, new results on the extraction of gluon helicity PDFs have been presented. These new results provide a comprehensive global analysis involving double spin asymmetries from high-energy polarized jet data, large-x polarized DIS, and recent calculations from LQCD. In this talk, I will provide a summary of the recent findings.
When quarkonium is produced in the low-transverse momentum region, the contribution of soft and ultra-soft radiation between the heavy-quark pair becomes relevant. At this region, non-relativistic QCD (NRQCD) breaks down and we need to promote the long-distance matrix elements to the TMD shape functions (TMDShFs) in the NRQCD factorization procedure. In this talk, I discuss the cross section...
Quarkonia are very "handy" objects for the spin-physics community because they can be used to fill up the lack of information on gluon transverse momentum dependent distributions (TMDs) at energies $Q \lesssim 100$ GeV. In particular, among the different kinds of quarkonia, the $J/\psi$ is definitely the one that attracts the most attention. Nonetheless, its theoretical description is still...
Within the framework of transverse momentum dependent factorization in combination with nonrelativistic QCD, we study charmonium and bottomonium production in hadronic collisions. We focus on quarkonium states with even charge conjugation, for which the color-singlet production mechanism is expected to be dominant in the small transverse momentum region, $q^2_T \ll 4M^2_{c,b}$. It is shown...
We present a calculation of the single-spin asymmetry (SSA) for the single-inclusive production of hadrons in collisions of transversely polarized protons
and unpolarized electrons, ep↑ → hX. We compute this transverse spin observable
within the collinear twist-3 factorization approach in perturbative QCD to next-to-leading order (NLO) accuracy. Several production channels contribute at NLO...
A back-to-back semi-inclusive $J/\psi + jet$ production is a promising process to study gluon transverse momentum distribution (TMDs) at the future electron-ion collider (EIC). A back-to-back configuration allows a higher transverse momentum for $J/\psi$. We present an extension of a previous work where we studied $cos2\phi$ azimuthal asymmetry within the TMD factorization framework. We...
Double spin asymmetries for particle and jet productions in longitudinally polarized proton-proton collisions have been the flagship measurements at RHIC to study proton’s spin content originating from gluons. Conventional theoretical framework used to extract gluons’ helicity distribution relies on the collinear factorization framework which is applicable primarily when there exists a large...
