In this talk I will briefly address the state of the art for our understanding of transverse-momentum-dependent distributions. I will also introduce some of the topics which are currently under investigation and highlight the fundamental role of the present experimental facilities for the advancement of the field.
TMDs match collinear PDFs in the limit of small transverse distances. We study the bias on the TMD extraction caused by the choice of the PDF set. The bias is reduced by introducing a flavour dependence on the TMD profile and taking into account the PDF uncertainty. Both points improve the agreement between theory and experiment and should be taken into account in future global analyses.
The azimuthal correlation of high transverse momentum jets in collisions at 13 TeV is studied by applying PB-TMD distributions to NLO calculations via MCatNLO together with the PB-TMD parton shower in Cascade3. A very good description of the cross section as a function of the azimuthal correlation is observed. In the back-to-back region, a very good agreement is observed with the PB-TMD Set 2...
The talk is devoted to the TMD distributions of twist-three and presents their systematic, evolution equations, small-b matching, and other properties. I explicitly demonstrate the non-trivial interplay between T-odd and T-even distributions and the presence of super-leading-power terms.
A complete Monte Carlo event generator capable of accounting for quark spin effects in hadronization and other stages of the event generation in a consistent way is still lacking. An essential prerequisite to reach this goal is a sound model of hadronization such as the quantum mechanical string+${}^3P_0$ model. The string+${}^3P_0$ model describes the polarized quark fragmentation process...
In this talk I will give a brief overview of the current status of the nuclear modifications in PDFs and FFs.
We study the correlations between the second flow harmonic v(2) and multiplicity of produced particles using the dilute-dense approach to Color Glass Condensate (CGC). We find an interesting correlation structure which depends on the width of the bin in transverse momentum. The physics of this dependence is the crossover between. HBT - dominated and Bose Einstein dominated correlations as a...
We present exploratory analyses of the 3D gluon content of the proton via a study of polarized gluon TMDs at leading-twist, calculated in a spectator model for the parent nucleon. Our approach encodes a flexible parameterization for the spectator-mass density, suited to describe both moderate- and small-$x$ effects. We show preliminary results on the application of our gluon TMDs to reactions...
We provide the first calculation of two-gluon production at mid-rapidity in ultra-peripheral collisions in the Color Glass Condensate framework. To estimate systematic uncertainty associated with poor understanding of the wave function of the nearly real photon, we consider two diametrically different models: the dilute quark-antiquark dipole approximation and a
vector meson, in which...
