Publications [#287619] of Thomas C. Mehen

Papers Published
  1. Fleming, S; Leibovich, AK; Mehen, T, J/Ψ photo-production at large z in soft collinear effective theory, Proceedings of the Ringberg Workshop on New Trends in HERA Physics 2005 (January, 2006), pp. 239-250(to be published in proceedings of the Ringberg Conference: New Trends in HERA Physics, World Scientific, 2006.) [0512194] .

    One of the outstanding problems in J/Ψ physics is a systematic understanding of the differential photo-production cross section dσ/dz(γ+p → J/Ψ + X), where z = E Ψ ,/E gamma; / in the proton rest frame. The theoretical prediction based on the nonrelativistic QCD (NRQCD) factorization formalism has a color-octet contribution which grows rapidly in the endpoint region, z -→ 1, spoiling perturbation theory. In addition there are subleading operators which are enhanced by powers of 1/(1 - z) and they must be resummed to all orders. Here an update of a systematic analysis is presented. The approach used to organize the endpoint behavior of the photoproduction cross section is based on a combination of NRQCD and soft collinear effective theory. While a final result is not yet available, an intermediate result indicates that better agreement between theory and data will be achieved in this framework. Copyright © 2006 by World Scientific Publishing Co. Pte. Ltd.