Tübingen 2003 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HK: Physik der Hadronen und Kerne

HK 35: Plenarsitzung

HK 35.4: Plenarvortrag

Donnerstag, 20. März 2003, 10:00–10:30, P

Medium Modification of Hadrons in Photon Induced Reactions — •Susan Schadmand — II. Physikalsiches Institut, JLU Giessen

Differences in the photoproduction of mesons on the free proton and on nuclei are expected to reveal changes in the properties of hadrons. Inclusive studies of nuclear photoabsorption and photofission have already provided evidence of medium modifications. However, the results have to date not been explained in a model independent way. A deeper understanding of the situation is anticipated from a detailed experimental study of meson photoproduction from nuclei in exclusive reactions. In the energy regime above the Δ(1232) resonance, the dominant double pion production channels are of particular interest. Double pion photoproduction from nuclei is also used to investigate the in-medium modification of meson-meson interactions. A comparison of π^∘π^∘ and π^∘π^± production from different nuclei shows a dependence on the nuclear density as well as the available center-of-mass energy. This hints at a modified pion-pion interaction in the nuclear medium and possibly the in-medium modification of light scalar and vector mesons.

In this contribution, recent results from photonuclear experiments with the photon spectrometer TAPS are presented and discussed in the frame work of different model predictions. The measurements were conducted at the tagged photon facility at the Mainz Microtron MAMI.