The Fully-Differential Quark Beam Function at NNLO

Abstract

We present the first calculation of a fully-unintegrated parton distribution (beam function) at next-to-next-to-leading order (NNLO). We obtain the fully-differential beam function for quark-initiated processes by matching it onto standard parton distribution functions (PDFs) at two loops. The fully-differential beam function is a universal ingredient in resummed predictions of observables probing both the virtuality as well as the transverse momentum of the incoming quark in addition to its usual longitudinal momentum fraction. For such double-differential observables our result provides the part of the NNLO singular cross section related to collinear initial-state radiation (ISR), and is important for the resummation of large logarithms through N3LL.

17 pages, 1 figure; v2: journal version

References in corpus (13)

• The Zero-Bin and Mode Factorization in Quantum Field Theory
• HypExp 2, Expanding Hypergeometric Functions about Half-Integer Parameters
• Treating the b quark distribution function with reliable uncertainties
• The Quark Beam Function at NNLL
• Fully Unintegrated Parton Correlation Functions and Factorization in Lowest Order Hard Scattering
• Transverse-momentum resummation for top-quark pairs at hadron colliders
• Glauber Gluons and Multiple Parton Interactions
• The Gluon Beam Function at Two Loops
• Resummation of Large Endpoint Corrections to Color-Octet J/psi Photoproduction
• Transverse Momentum Distributions from Effective Field Theory with Numerical Results
• Rapidity-Dependent Jet Vetoes
• Need for fully unintegrated parton densities
• Next-to-Leading Order Hard Scattering Using Fully Unintegrated Parton Distribution Functions

Cited by in corpus (1)

• Resummation of Double-Differential Cross Sections and Fully-Unintegrated Parton Distribution Functions