Authors: Tao Han Josh Sayre Susanne Westhoff
Publish Date: 2015/04/27
Volume: 2015, Issue: 4, Pages: 145-
Abstract
In hadronic collisions at high energies the topquark may be treated as a parton inside a hadron Topquark initiated processes become increasingly important since the topquark luminosity can reach a few percent of the bottomquark luminosity In the production of a heavy particle H with mass m H m t treating the topquark as a parton allows us to resum large logarithms logm H 2 /m t 2 arising from collinear splitting in the initial state We quantify the effect of collinear resummation at the 14TeV LHC and a future 100TeV hadron collider focusing on the topquark openflavor process ggto toverlinetH in comparison with toverlinetto H and tg → tH at the leading order LO in QCD We employ topquark parton distribution functions with appropriate collinear subtraction and power counting We find that 1 collinear resummation enhances the inclusive production of a heavy particle with m H ≈ 5 TeV 05 TeV by more than a factor of two compared to the openflavor process at a 100TeV 14TeV collider 2 topquark mass effects are important for scales m H near the topquark threshold where the cross section is largest We advocate a modification of the ACOT factorization scheme dubbed mACOT that consistently treats heavyquark masses in hadronic collisions with two initial heavy quarks 3 the scale uncertainty of the total cross section in mACOT is of about 20 at the LO While a higherorder calculation is indispensable for a precise prediction the LO cross section is well described by the process toverlinetto H using an effective factorization scale significantly lower than m H We illustrate our results by the example of a heavy spin0 particle Our main results also apply to the production of particles with spin1 and 2This article is published under an open access license Please check the Copyright Information section for details of this license and what reuse is permitted If your intended use exceeds what is permitted by the license or if you are unable to locate the licence and reuse information please contact the Rights and Permissions team
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