One-loop matching for spin-dependent quasi-TMDs

We compute the contribution of twist-2 and twist-3 parton distribution functions to the small-b expansion for transverse momentum dependent (TMD) distributions at all powers of b. The computation is done by the twist-decomposition method based on the spinor formalism for all eight quark TMD distributions. The newly computed terms are accompanied by the prefactor (M2b2)n and represent the target-mass corrections to the resummed cross-section. For the first time, a non-trivial expression for the pretzelosity distribution is derived.

Section: Resultsmentioning

confidence: 99%

“…The same statement holds for the quasi-TMDs for which the non-trivial but -suppressed matching to pretzelosity has been observed in ref. [55] at α s -order.…”

Section: Jhep12(2020)145mentioning

confidence: 96%

Calculation of transverse momentum dependent distributions beyond the leading power

Moos

Vladimirov

2020

“…The progress in NNLO calculation for TMD distributions have allowed many cutting-edge calculations for phenomenology, including fixed-order calculation at NNLO and beyond [29][30][31][32][33][34] and resummation for large logarithms at small q T at unprecedented N 3 LL accuracy [34][35][36][37][38][39][40][41]. We also note that perturbative calculation for TMD quantities suitable for lattice calculation [42][43][44][45] has also made important progress recently [46].…”

Section: Introductionmentioning

confidence: 88%

Unpolarized quark and gluon TMD PDFs and FFs at N3LO

Luo

Yang

Zhu

et al. 2021

In this paper we calculate analytically the perturbative matching coefficients for unpolarized quark and gluon Transverse-Momentum-Dependent (TMD) Parton Distribution Functions (PDFs) and Fragmentation Functions (FFs) through Next-to-Next-to-Next-to-Leading Order (N3LO) in QCD. The N3LO TMD PDFs are calculated by solving a system of differential equation of Feynman and phase space integrals. The TMD FFs are obtained by analytic continuation from space-like quantities to time-like quantities, taking into account the probability interpretation of TMD PDFs and FFs properly. The coefficient functions for TMD FFs exhibit double logarithmic enhancement at small momentum fraction z. We resum such logarithmic terms to the third order in the expansion of αs. Our results constitute important ingredients for precision determination of TMD PDFs and FFs in current and future experiments.

“…refs. [178][179][180][181][182][183][184][185][186] for recent progress towards calculating TMDPDFs on lattice, and refs. [187,188] for a more general overview of parton physics from lattice QCD.…”

Section: Beam Functionsmentioning

confidence: 99%

Collinear expansion for color singlet cross sections

Ebert

Mistlberger

Vita

2020

Self Cite

We demonstrate how to efficiently expand cross sections for color-singlet production at hadron colliders around the kinematic limit of all final state radiation being collinear to one of the incoming hadrons. This expansion is systematically improvable and applicable to a large class of physical observables. We demonstrate the viability of this technique by obtaining the first two terms in the collinear expansion of the rapidity distribution of the gluon fusion Higgs boson production cross section at next-to-next-to leading order (NNLO) in QCD perturbation theory. Furthermore, we illustrate how this technique is used to extract universal building blocks of scattering cross section like the N-jettiness and transverse momentum beam function at NNLO.