相关论文: Soft factors for double parton scattering at NNLO
The renormalization-group properties of gauge-invariant transverse-momentum dependent (TMD) parton distribution functions (PDF) in QCD are addressed. We perform an analysis of their leading-order anomalous dimensions, which are local…
The quasi-transverse-momentum dependent (qTMD) distributions are equal-time correlators that can be computed within the lattice QCD approach. In the regime of large hadron's momentum, qTMD distributions are expressed in terms of standard…
We present a comprehensive study of the angular structure functions for Drell-Yan leptons in $Z/\gamma$-boson production within the framework of the transverse momentum dependent (TMD) factorization theorem, including kinematic power…
In this paper, we study phenomenologically interesting soft radiation distributions in massless QCD. Specifically, we consider the emission of two soft partons off of a pair of light-like Wilson lines, in either the fundamental or the…
We consider QCD radiative corrections to the production of a heavy-quark pair in hadronic collisions. We present the computation of the soft-parton contributions at low transverse momentum of the heavy-quark pair up to second order in the…
Simple generic expressions to compute double-parton scattering (DPS) cross sections in high-energy proton-nucleus and nucleus-nucleus collisions, as a function of the corresponding single-parton cross sections, are presented. Estimates of…
The cross section for top quark pair production factorizes at small transverse momentum of the heavy quark pair, $q_T$. One of the key ingredients that appears in the factorization formula is the soft function, which mediates soft gluon…
Parametrizing TMD parton densities and fragmentation functions in ways that consistently match their large transverse momentum behavior in standard collinear factorization has remained notoriously difficult. We show how the problem is…
We discuss the single-parton and double-parton scattering (SPS or DPS) effects in four-jet production at the LHC. The calculations of both single-parton and double-parton scattering components are done in the high-energy (or…
We present a global analysis of Sivers functions, transversity distribution functions, and Collins fragmentation functions within the transverse momentum dependent factorization. This analysis encompasses the latest data from semi-inclusive…
We show that the transverse double spin asymmetry (DSA) in the Drell-Yan process contributed only from the Sivers functions can be picked out by the weighting function…
The parton distributions functions (PDFs) derived from the NNLO QCD analysis of existing light-targets deep-inelastic-scattering data are presented. The NLO and NNLO PDFs are compared in order to analyze perturbative stability of the…
Extending the concept of parton densities onto nonforward matrix elements <p'|O(0,z)|p> of quark and gluon light-cone operators, one can use two types of nonperturbative functions: double distributions (DDs) f(x,\alpha;t), F(x,y;t) and…
In this work we directly fit the QCD dimensional transmutation parameter, ${\Lambda _{\overline {MS} }}$, to experimental data of Drell-Yan (DY) observables. For this purpose we first obtain the evolution of transverse momentum dependent…
We discuss two topics in double parton scattering (DPS) theory that have been the subject of recent research interest. First, the role of `double parton splitting' diagrams in DPS is discussed. We outline the `double PDF' description of…
The Drell-Yan process is studied in the framework of TMD factorization in the Sudakov region $s\gg Q^2\gg q_\perp^2$ corresponding to recent LHC experiments with $Q^2$ of order of mass of Z-boson and transverse momentum of DY pair $\sim$…
We present a systematic framework to study the threshold contributions of the differential rapidity distribution for the production of any number of colorless particles in the hadronic colliders. This has been achieved based on the…
Transverse momentum dependent parton distribution functions (TMDPDFs) encode information about the intrinsic motion of quarks inside the nucleon. They are important non-perturbative ingredients in our understanding of, e.g., azimuthal…
We discuss the double-parton scattering (DPS) effects in four-jet production at the LHC. A special attention is given to the optimization of kinematical conditions in order to enhance the relative contribution of DPS in four-jet sample. The…
We discuss a modification of the next-to-next-to-leading order (NNLO) subtraction scheme based on the residue-improved sector decomposition that reduces the number of double-real emission sectors from five to four. In particular, a sector…