相关论文: Gluon TMDs in the small-$x$ limit
We establish robust relations between Transverse Momentum Dependent distributions (TMDs) and collinear distributions. We define weighted integrals of TMDs that we call Transverse Momentum Moments (TMMs) and prove that TMMs are equal to…
We discuss different operator definitions of the transverse-momentum dependent (TMD) parton densities from the point of view of their renormalization-group (RG) properties and UV evolution. We also consider the structure of the gauge links…
Analytical expressions for the Transverse Momentum Dependent (TMD, or unintegrated) gluon and sea quark densities in nuclei are derived at leading order of QCD running coupling. The calculations are performed in the framework of the…
The computation of observables in high energy QCD involves an average over stochastic semiclassical small-x gluon fields. The weight of various configurations is determined by the effective action. We introduce a method to study…
We calculate the transverse momentum p_T distribution for production of the Upsilon states in hadronic reactions. For small $p_T (\leq M_\Upsilon)$, we resum to all orders in the strong coupling alpha_s the process-independent large…
In our previous work we established a formalism which allows one to determine the small-$x$ asymptotics of any transverse momentum-dependent parton distribution function (TMD PDF) of the proton at small values of strong coupling. In this…
We consider the region of small transverse momenta in the production of high-mass systems in hadronic collisions. By using the current knowledge on the infrared behaviour of tree-level and one-loop QCD amplitudes at O(alpha_s^2), we…
The production of a hard dijet with small transverse momentum imbalance in semi-inclusive DIS probes the conventional and linearly polarized Weizsaecker-Williams (WW) Transverse Momentum Dependent (TMD) gluon distributions. The latter, in…
Central to understanding the nonpertubative, intrinsic partonic nature of hadron structure are the concepts of transverse momentum dependent (TMD) parton distribution and fragmentation functions. A TMD factorization approach to the…
We discuss the possibility of non-minimal gauge invariance of transverse-momentum-dependent parton densities (TMDs) that allows direct access to the spin degrees of freedom of fermion fields entering the operator definition of (quark) TMDs.…
We derive relations between polarized transverse momentum dependent distribution functions (TMDs) and the usual parton distribution functions (PDFs) in the 3D covariant parton model, which follow from Lorentz invariance and the assumption…
We study forward dijet production in dilute-dense hadronic collisions. By considering the appropriate limits, we show that both the transverse-momentum-dependent (TMD) and the high-energy factorization formulas can be derived from the Color…
We compute the gluon transverse-momentum-dependent fragmentation function (TMDFF) at next-to-leading order (NLO) into heavy quarkonium in the color-octet $^3S_1^{[8]}$ channel, based on the NRQCD factorization approach. The spurious…
Transverse-momentum-dependent parton distributions (TMDs) provide three-dimensional images of the partonic structure of the nucleon in momentum space. We made impressive progress in understanding TMDs, both from the theoretical and…
We discuss the treatment of intrinsic transverse momenta in high energy scattering processes. Within the field theoretical framework of QCD the process is described in terms of correlators containing quark and gluon fields. The correlators,…
We investigate the emergence of single spin asymmetries (SSA) in hard processes using transverse momentum dependent (TMD) distribution and fragmentation functions. Specifically, the description of SSA involves time reversal-odd functions.…
We consider the interaction of the partonic fluctuation of a scalar ``photon'' with an external color field to calculate the leading and next-to-leading order gluon distribution of the proton following the work done by…
Using a generalized parton model approach including spin and intrinsic parton motion effects, and assuming the validity of factorization for large p_T jet production in hadronic collisions, we study the azimuthal distribution around the jet…
We consider photon pair production in hadronic collisions at large mass and small transverse momentum of the pair, assuming that factorization in terms of transverse momentum dependent parton distributions applies. The unpolarized cross…
Parton branching methods underlie the Monte Carlo (MC) generators, being therefore of key importance for obtaining high energy physics predictions. We construct a new parton branching algorithm which for the first time incorporates the…