A Challenge for Discrimination of Color-Singlet versus Color-Octet Quarkonium Production

Journal Article · Thu Feb 03 04:00:00 EST 2022 · arXiv

DOI:https://doi.org/10.48550/arXiv.2202.01812· OSTI ID:1847094

Larkoski, Andrew ^[1]

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1. SLAC National Accelerator Lab., Menlo Park, CA (United States), FPD Theory Elem Particle Phys; SLAC

The precise mechanism for production of quarkonium at hadron colliders is still an open question. Within non-relativistic quantum chromodynamics, quarkonium production cross sections can be factorized into short-distance, perturbative contributions and universal, non-perturbative, long-distance matrix elements, and then summed over quantum numbers of the heavy quark pair. In principle, at short-distances, the heavy quark pair can be either in a color-singlet or color-octet state, and it is desirable to establish the relative contributions to compare with data and to make predictions in different experimental environments. From the explicit form of the lowest-order perturbative matrix elements for color-singlet and color-octet production, we show that the structure of the optimal observable for discrimination on phase space, the likelihood ratio, has strong dependence on the angular momentum state of the heavy quark pair. This presents an obstruction for construction of a single, robust discrimination observable that can be applied to production of an arbitrary quarkonium state.

• Research Organization: SLAC
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 1847094
• Journal Information: arXiv, Journal Name: arXiv
• Country of Publication: United States
• Language: English