Fragmentation production of and ψ′ at the Tevatron

Abstract

We present a calculation of the charm and gluon fragmentation contributions to inclusive J/ψ and ψ ′ production at large transverse momentum at the Tevatron. For ψ production, we include both fragmentation directly into ψ and fragmentation into χ c followed by the radiative decay χ c → ψ+γ. We find that fragmentation overwhelms the leading-order mechanisms for prompt ψ production at large p T , and that the dominant contributions come from fragmentation into χ c . Our results are consistent with recent data on ψ production from the CDF and D0 experiments. In the case of prompt ψ ′ production, the dominant mechanism at large p T is charm fragmentation into ψ ′ . We find serious disagreement between our theoretical predictions and recent ψ ′ data from the Tevatron.

Complete next-to-leading order calculation of theJ/ψandψ′production at hadron colliders

“…But, as studied in ref. [21], these fragmentation contributions are ignorable, compared with experimental prompt production data of J/ψ, and we will further argue about this point in Sec. III A.…”

Application of gluon to heavy quarkonium fragmentation functions

“…(1). However when the momentum of the fragmenting gluon remains finite, these non-covariant definitions of z may induce large uncertainties in the application of the fragmentation functions.…”

Inelastic photoproduction

“…For elastic/diffractive events z is close to one; the inelastic events are experimentally restricted in general to the range z < 0.9 [6]. The production of J/ψ particles at large transverse momenta is dominated by gluon fragmentation mechanisms [7].…”