Transverse momentum dependent feed-down fractions for bottomonium production

TL;DR

This paper determines how much bottomonium production comes from direct production versus decay from excited states, using data from LHC experiments to provide detailed, momentum-dependent feed-down fractions.

Contribution

It introduces a data-driven method to extract transverse momentum dependent feed-down fractions for bottomonium, incorporating multiple experimental datasets and providing results in tabulated form.

Findings

Approximately 75% of Upsilon(1S) and Upsilon(2S) are produced directly.

Feed-down fractions strongly depend on transverse momentum.

Results are consistent with previous studies and are publicly available.

Abstract

We extract transverse momentum dependent feed-down fractions for bottomonium production using a data-driven approach. We use data published by the ATLAS, CMS, and LHCb Collaborations for sqrt(s) = 7 TeV proton-proton collisions. Based on this collected data, we produce fits to the differential cross sections for the production of both S- and P-wave bottomonium states. Combining these fits with branching ratios for excited state decays from the Particle Data Group, we compute the feed-down fractions for both the Upsilon(1S) and Upsilon(2S) as a function of transverse momentum. Our results indicate a strong dependence on transverse momentum, which is consistent with prior extractions of the feed-down fractions. When evaluated at the average momentum of the states, we find that approximately 75% of Upsilon(1S) and Upsilon(2S) states are produced directly. Our results for the transverse momentum dependent feed-down fractions are provided in tabulated form so that they can be used by other research groups.