{"paper":{"title":"Is $\\hat{q}$ a physical quantity or just a parameter? and other unanswered questions in High-$p_T$ Physics","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"M. J. Tannenbaum","submitted_at":"2015-04-14T18:38:03Z","abstract_excerpt":"The many different theoretical studies of energy loss of a quark or gluon traversing a medium have one thing in common: the transport coefficient of a gluon in the medium, $\\hat{q}$, which is defined as the mean 4-momentum transfer$^2$, $\\left<q^2\\right>$, by a gluon to the medium per gluon mean free path, $\\lambda_{\\rm mfp}$. In the original BDMPSZ formalism, the energy loss of an outgoing parton, $-dE/dx$, per unit length ($x$) of a medium with total length $L$, due to coherent gluon bremsstrahlung, is proportional to the $\\left< q^2\\right>$ and takes the form: ${-dE/dx }\\simeq \\alpha_s \\lef"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1504.03657","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}