Prompt Upsilon(nS) production at the LHC in the Regge limit of QCD

TL;DR

This paper investigates prompt Upsilon(nS) meson production at the LHC using gluon Reggeization and nonrelativistic QCD, successfully fitting experimental data and predicting spectra across multiple experiments and energies.

Contribution

It introduces a novel approach combining gluon Reggeization with nonrelativistic QCD to describe Upsilon production at high energies.

Findings

Good agreement with LHC measurements at 7 TeV

Accurate predictions for CMS and LHCb spectra

Consistent results with Fermilab Tevatron data

Abstract

We study prompt Upsilon(nS) hadroproduction (n=1,2,3) invoking the hypothesis of gluon Reggeization in t-channel exchanges at high energy and the factorization formalism of nonrelativistic quantum chromodynamics at leading order in the strong-coupling constant alpha_s and the relative velocity v of the bound quarks. The transverse-momentum distributions of prompt Upsilon(nS)-meson production measured by the ATLAS Collaboration at the CERN LHC are fitted to obtain the color-octet nonperturbative long-distance matrix elements, which are used to predict prompt Upsilon(nS) production spectra measured by the CMS and LHCb Collaborations. At the numerical calculation, we adopt the Kimber-Martin-Ryskin prescription to derive unintegrated gluon distribution function of the proton from its collinear counterpart, for which we use the Martin-Roberts-Stirling-Thorne set. We find good agreement with measurements by the ATLAS, CMS and LHCb Collaborations at the LHC at the hadronic c.m. energy sqrt S=7 TeV as well as with measurements by the CDF Collaboration at the Fermilab Tevatron.