Relativistic Correction to J/psi and Upsilon Pair Production

TL;DR

This paper investigates relativistic corrections to double J/psi, Upsilon, and J/psi+Upsilon production at Tevatron and LHC within nonrelativistic QCD, revealing significant effects on cross sections and model explanations.

Contribution

It provides detailed calculations of relativistic corrections to pair production processes, showing their impact on cross sections and the adequacy of single parton scattering models.

Findings

Relativistic corrections reduce cross sections by approximately 23% for double J/psi production.

The corrections significantly diminish differences between color-singlet and color-octet differential cross sections.

Single parton scattering may sufficiently explain LHCb J/psi pair production data.

Abstract

The relativistic corrections to the productions of double J/psi, double Upsilon, and J/psi+Upsilon at the Tevatron and the LHC were investigated within the frame of nonrelativistic QCD. The ratios of short distance coefficients between relativistic correction and leading order result for color singlet and color octet states in large p_T limit are approximately -1,-11/3, respectively, for pair production. And for J/psi+Upsilon process the ratio is -11/6 for the CO channel. The K factors of relativistic corrections for color singlet and color octet double J/psi production are -0.23 and -0.84 with adopting v^2=0.23. The relativistic corrections significantly dilute the difference between the shape of color-singlet differential cross sections and the color-octet's at leading order. Also our results show that the single parton scattering model may be enough to explain the LHCb data for the J/psi pair production.