Transverse momentum spectrum of dilepton pair in the unpolarized $\pi^-N$ Drell-Yan process within TMD factorization

TL;DR

This paper investigates the transverse momentum distribution of dileptons in unpolarized pion-nucleon Drell-Yan processes using TMD factorization, extracting nonperturbative effects from experimental data and comparing theoretical predictions with recent measurements.

Contribution

It introduces a method to extract the nonperturbative Sudakov form factor for the pion within TMD evolution and applies it to analyze experimental data.

Findings

Successful extraction of the pion's Sudakov form factor from Fermilab data.

Theoretical calculations agree well with COMPASS measurements.

Enhanced understanding of nonperturbative effects in TMD factorization.

Abstract

We study the transverse momentum spectrum of dilepton produced in the unpolarized $\pi^- N$ Drell-Yan process, using transverse momentum dependent factorization up to next-to-logarithmic order of QCD. We extract the nonperturbative Sudakov form factor for the pion in the evolution formalism of the unpolarized TMD distribution function, by fitting the experimental data collected by the E615 Collaboration at Fermilab. With the extracted Sudakov factor, we calculate the normalized differential cross section with respect to transverse momentum of the dimuon and compare it with the recent measurement by the COMPASS Collaboration.