Variable Flavor Number Scheme for Final State Jets in DIS

Author(s)
André H. Hoang, Piotr Pietrulewicz, Daniel Samitz
Abstract

We discuss massive quark effects in the end-point region x→1 of inclusive deep inelastic scattering (DIS), where the hadronic final state is collimated and thus represents a jet. In this regime heavy quark pairs are generated via secondary radiation, i.e. due to a gluon splitting in light quark initiated contributions starting at O(αs2) in the fixed-order expansion. Based on the factorization framework for DIS in the end-point region for massless quarks in soft collinear effective theory (SCET), which we also scrutinize in this work, we construct a variable flavor number scheme that deals with arbitrary hierarchies between the mass scale and the kinematic scales. The scheme exhibits a continuous behavior between the massless limit for very light quarks and the decoupling limit for very heavy quarks. It entails threshold matching corrections, arising from all gauge-invariant factorization components at the mass scale, which are related to each other via consistency conditions. This is explicitly demonstrated by recalculating the known threshold correction for the parton distribution function at O(αs2CFTF) within SCET. The latter contains large rapidity logarithms ∼ln(1-x) that can be summed by exponentiation. Their coefficients are universal, which can be used to obtain potentially relevant higher-order results for generic threshold corrections at colliders from computations in DIS. In particular, we extract the O(αs3) threshold correction multiplied by a single rapidity logarithm from results obtained earlier.

Organisation(s)
Particle Physics, Research Platform Erwin Schrödinger International Institute for Mathematics and Physics
External organisation(s)
Deutsches Elektronen-Synchrotron DESY
Journal
Physical Review D
Volume
93
No. of pages
26
ISSN
1550-7998
Publication date
02-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
103036 Theoretical physics, 103034 Particle physics, 103012 High energy physics
Keywords
ASJC Scopus subject areas
Physics and Astronomy (miscellaneous)
Portal url
https://ucrisportal.univie.ac.at/en/publications/variable-flavor-number-scheme-for-final-state-jets-in-dis(d9fa0a46-6273-46dc-8cfd-d1d4b7f20a0b).html