T-odd effects in photon-jet production at the Tevatron

TL;DR

This paper investigates T-odd effects in photon-jet production at the Tevatron, proposing that a specific azimuthal asymmetry related to the transverse momentum dependent parton distribution function can be observed, providing new insights into spin-momentum correlations.

Contribution

It introduces a method to study T-odd, spin and transverse momentum dependent parton distribution functions through photon-jet azimuthal asymmetries at the Tevatron.

Findings

Estimated asymmetry is smaller than Drell-Yan but still significant for Tevatron.

Provides explicit expression for the azimuthal asymmetry in photon-jet production.

Suggests a new way to probe T-odd effects in high-energy collisions.

Abstract

The angular distribution in photon-jet production in p \bar{p} -> \gamma jet X is studied within a generalized factorization scheme taking into account the transverse momentum of the partons in the initial hadrons. Within this scheme an anomalously large cos(2\phi) asymmetry observed in the Drell-Yan process could be attributed to the T-odd, spin and transverse momentum dependent parton distribution function h_1^{\perp q}(x, p_{\perp}^2). This same function is expected to produce a cos(2\phi) asymmetry in the photon-jet production cross section. We give the expression for this particular azimuthal asymmetry, which is estimated to be smaller than the Drell-Yan asymmetry but still of considerable size for Tevatron kinematics. This offers a new possibility to study T-odd effects at the Tevatron.