Soft photon production rate in resummed perturbation theory of high temperature QCD
نویسنده
چکیده
We calculate the production rate of soft real photons from a hot quark-gluon plasma using Braaten-Pisarski's perturbative resummation method. To leading order in the QCD coupling constant 9 we find a logarithmically divergent result for photon energies of order 9T, where T is the plasma temperature. This divergent behaviour is due to unscreened mass singularities in the effective hard thermal loop vertices in the case of a massless external photon.
منابع مشابه
ar X iv : h ep - p h / 99 10 24 0 v 1 5 O ct 1 99 9 Resummation for direct photon and W + jet production
Direct photon production and W + jet production are processes of great interest for a number of reasons. Direct photon production is important for determinations of gluon distributions whileW + jet production is relevant for estimating backgrounds to new physics. Near threshold for the production of the final state in these processes one can resum logarithmic corrections originating from soft g...
متن کاملTheory versus experiments in heavy flavour production
I discuss the current status of the comparison between theoretical predictions and experimental data, relevant to the production of open charm and bottom quarks in photon-hadron and photon-photon collisions. I advocate the use of a formalism that matches fixed-order computations to resummed computations in order to make firm statements on heavy flavour production as described by perturbative QCD.
متن کاملTop quark inclusive differential distributions.
The inclusive transverse momentum and rapidity distributions for top quark production at the Fermilab Tevatron are presented both in order α 3 s in QCD and using the resummation of the leading soft gluon corrections in all orders of QCD perturbation theory. The resummed results are uniformly larger than the O(α 3 s) results for both distributions.
متن کاملJoint Resummation for Heavy Quark Production
1. Joint threshold and recoil resummation The formalism 1,2,3 of hadronic cross sections for the joint resummation of distributions singular at partonic threshold and at zero recoil has so far been applied to Z/W production 4, Higgs production 5, and prompt photon hadroproduction 6. For the latter 2 → 2 process, the formalism implements the notion that, in the presence of QCD radiation, the act...
متن کاملThreshold resummation for high-transverse-momentum Higgs production at the LHC
We study the resummation of large logarithmic QCD corrections for the process pp → H + X when the Higgs boson H is produced at high transverse momentum. The corrections arise near the threshold for partonic reaction and originate from soft gluon emission. We perform the all-order resummation at next-to-leading logarithmic accuracy and match the resummed result with the next-to-leading order per...
متن کامل