[Submitted on 19 Nov 2015] (cross-list from hep-ph)
QCD Evolution of Superfast Quarks
Adam J. Freese🇺🇸 · Wim Cosyn🇧🇪 · Misak M. Sargsian🇺🇸
Recent high-precision measurements of nuclear deep inelastic scattering at high x and moderate 6 < Q < 9GeV give a rare opportunity to reach the quark distributions in the {\it superfast} region, in which the momentum fraction of the nucleon carried by its constituent quark is larger than the total fraction of the nucleon at rest, x>1. We derive the leading-order QCD evolution equation for such quarks with the goal of relating the moderate-Q data to the two earlier measurements of superfast quark distributions at large 60 < Q < 200~GeV. Since the high-Q measurements gave strongly contradictory estimates of the nuclear effects that generate superfast quarks, relating them to the high-precision, moderate-Q data through QCD evolution allows us to clarify this longstanding issue. Our calculations indicate that the moderate-Q data at are in better agreement with the high-Q data measured in (anti)neutrino-nuclear reactions which require substantial high-momentum nuclear effects in the generation of superfast quarks. Our prediction for the high-Q and x>1.1 region is somewhat in the middle of the neutrino-nuclear and muon-nuclear scattering data.
- Comments:
- 8 pages and 5 figures, version to appear in Physical Review D 99, 114019
- Subjects:
- High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
- arXiv:
- 1511.06044 [pdf]