Publications [#287676] of Thomas C. Mehen

Papers Published
  1. Mehen, T, Testing quarkonium production with photoproduced JlΨ+ γ, Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 55 no. 7 (1997), pp. 4338-4343 .

    I compute the leading color-octet contributions to the process γ+p→JlΨ+ γ(+Χ) within the nonrelativistic QCD (NRQCD) factorization formalism. In the color-singlet model, JlΨ+ γ can only be produced when the photon interacts through its structure function, while the color-octet mechanism allows for production of Jl Ψ+ γ via direct photon-gluon fusion. Resolved photon processes can be distinguished easily from direct photon processes by examining the fraction of the incident photon energy carried away by the Jl Ψ in the event. Therefore, this process provides a conclusive test of the color-octet mechanism. Jl Ψ+ γ production is particularly sensitive to the NRQCD matrix element which figures prominently in the fragmentation production of Jl Ψ at large p⊥ in hadron colliders. I also examine the predictions of the color evaporation model (CEM) of quarkonium production and find that this process can easily discriminate between the NRQCD factorization formalism and the CEM.