Variable Flavor Number Scheme for Final State Jets in DIS

André H. Hoang (Korresp. Autor*in), Piotr Pietrulewicz, Daniel Samitz

Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed


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.

FachzeitschriftPhysical Review D
PublikationsstatusVeröffentlicht - 23 Feb. 2016

ÖFOS 2012

  • 103036 Theoretische Physik
  • 103034 Teilchenphysik
  • 103012 Hochenergiephysik