T-odd Effects in Photon-Jet Production at the Tevatron

TL;DR

This paper investigates T-odd, spin and transverse momentum dependent effects in photon-jet production at the Tevatron, proposing that azimuthal asymmetries can reveal novel insights into parton distributions.

Contribution

It introduces a generalized factorization scheme incorporating parton transverse momentum to analyze T-odd effects in photon-jet production.

Findings

The cos(2φ) asymmetry in photon-jet production is estimated to be smaller than in Drell-Yan but still significant.

The study suggests photon-jet azimuthal asymmetries can serve as a new probe for T-odd parton distribution functions.

Potential to observe T-odd effects at the Tevatron through measurable azimuthal asymmetries.

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). The same function is expected to produce a cos(2\phi) asymmetry in the photon-jet production cross section. This particular azimuthal asymmetry is estimated to be smaller than the Drell-Yan asymmetry but still of considerable size for Tevatron kinematics, offering a new possibility to study T-odd effects at the Tevatron.