{ "id": "nucl-th/0701045", "version": "v3", "published": "2007-01-17T18:42:45.000Z", "updated": "2007-05-29T12:22:03.000Z", "title": "Dihadron Tomography of High-Energy Nuclear Collisions in NLO pQCD", "authors": [ "Hanzhong Zhang", "J. F. Owens", "Enke Wang", "Xin-Nian Wang" ], "comment": "4 pages in revtex with 5 figures, final version in PRL The numerical tables of the NLO single and dihadron spectra used in this manuscript can be downloaded from ftp://www-nsdth.lbl.gov/pub/xnwang/dihadron/", "journal": "Phys.Rev.Lett.98:212301,2007", "doi": "10.1103/PhysRevLett.98.212301", "categories": [ "nucl-th", "hep-ph" ], "abstract": "Back-to-back dihadron spectra in high-energy heavy-ion collisions are studied within the next-to-leading order (NLO) perturbative QCD parton model with jet quenching incorporated via modified jet fragmentation functions due to radiative parton energy loss in dense medium. The experimentally observed appearance of back-to-back dihadrons at high $p_T$ is found to originate mainly from jet pairs produced close and tangential to the surface of the dense matter. However, a substantial fraction of observed high $p_T$ dihadrons also comes from jets produced at the center of the medium after losing finite amount of energy. Consequently, the suppression factor of such high-$p_T$ hadron pairs is found to be more sensitive to the initial gluon density than the single hadron spectra that are dominated by surface emission. A simultaneous $\\chi^2$-fit to both the single and dihadron spectra can be achieved within a narrow range of the energy loss parameters $\\epsilon_0=1.6-2.1$ GeV/fm. Because of the flattening of the initial jet production spectra, high $p_T$ dihadrons at the LHC energy are found to be more robust as probes of the dense medium.", "revisions": [ { "version": "v3", "updated": "2007-05-29T12:22:03.000Z" } ], "analyses": { "subjects": [ "12.38.Bx", "25.75.Gz", "12.38.Mh" ], "keywords": [ "high-energy nuclear collisions", "nlo pqcd", "dihadron tomography", "initial jet production spectra", "back-to-back dihadron" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Phys. Rev. Lett." }, "note": { "typesetting": "RevTeX", "pages": 4, "language": "en", "license": "arXiv", "status": "editable", "inspire": 742586 } } }