Global QCD Analysis of Pion Parton Distributions with Threshold Resummation
Abstract
We perform the first global QCD analysis of pion valence, sea quark, and gluon distributions within a Bayesian Monte Carlo framework with threshold resummation on Drell-Yan cross sections at next-to-leading log accuracy. Exploring various treatments of resummation, we find that the large-x asymptotics of the valence quark distribution ∼(1 -x )βv can differ significantly, with βv ranging from ≈1 to >2.5 at the input scale. Regardless of the specific implementation, however, the resummation induced redistribution of the momentum between valence quarks and gluons boosts the total momentum carried by gluons to ≈40 % , increasing the gluon contribution to the pion mass to ≈40 MeV .
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2021
- DOI:
- 10.1103/PhysRevLett.127.232001
- arXiv:
- arXiv:2108.05822
- Bibcode:
- 2021PhRvL.127w2001B
- Keywords:
-
- High Energy Physics - Phenomenology;
- High Energy Physics - Experiment;
- High Energy Physics - Lattice;
- Nuclear Theory
- E-Print:
- 6 pages, 3 figures