Photon bremsstrahlung and diffusive broadening of a hard jet
| dc.creator | Majumder, A. | |
| dc.creator | Fries, R. J. | |
| dc.creator | Müller, B. | |
| dc.date | 2007-11-15 | |
| dc.date | 2008-02-25 | |
| dc.date.accessioned | 2026-07-07T11:54:11Z | |
| dc.date.available | 2026-07-07T11:54:11Z | |
| dc.description | The photon bremsstrahlung rate from a quark jet produced in deep-inelastic scattering (DIS) off a large nucleus is studied in the collinear limit. The leading medium-enhanced higher twist corrections which describe the multiple scattering of the jet in the nucleus are re-summed to all orders of twist. The propagation of the jet in the absence of further radiative energy loss is shown to be governed by a transverse momentum diffusion equation. We compute the final photon spectrum in the limit of soft photons, taking into account the leading and next-to-leading terms in the photon momentum fraction y. In this limit, the photon spectrum in a physical gauge is shown to arise from two interfering sources: one where the initial hard scattering produces an off-shell quark which immediately radiates the photon and then undergoes subsequent soft re-scattering; alternatively the quark is produced on-shell and propagates through the medium until it is driven off-shell by re-scattering and radiates the photon. Our result has a simple formal structure as a product of the photon splitting function, the quark transverse momentum distribution coming from a diffusion equation and a dimensionless factor which encodes the effect of the interferences encountered by the propagating quark over the length of the medium. The destructive nature of such interferences in the small y limit are responsible for the origin of the Landau-Pomeranchuck-Migdal (LPM) effect. Along the way we also discuss possible implications for quark jets in hot nuclear matter. | |
| dc.description | 24 pages, 3 figures, Revtex4 | |
| dc.identifier | https://arxiv.org/abs/0711.2475 | |
| dc.identifier | http://arxiv.org/abs/0711.2475 | |
| dc.identifier | Phys.Rev.C77:065209,2008 | |
| dc.identifier | doi:10.1103/PhysRevC.77.065209 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/204804 | |
| dc.subject | Nuclear Theory | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Photon bremsstrahlung and diffusive broadening of a hard jet | |
| dc.type | text |