In-medium properties of hadrons—observables II

Abstract

In this review we discuss the observable consequences of in-medium changes of hadronic properties in reactions with elementary probes, and in particular photons, on nuclei. After an outline of the theoretical method used we focus on a discussion of actual observables in photonuclear reactions; we discuss in detail 2π-and vector-meson production. We show that the 2π 0 photoproduction data can be well described by final state interactions of the pions produced whereas the semi-charged π 0 π ± channel exhibits a major discrepancy with theory. For ω production on nuclei in the TAPS/CB@ELSA experiment we analyse the π 0 γ decay channel, and illustrate the strength of the method by simulating experimental acceptance problems. Completely free of final state interactions is dilepton production in the few GeV range. We show that the sensitivity of this decay channel to changes of hadronic properties in medium in photonuclear reactions on nuclei is as large as in ultrarelativistic heavy ion collisions and make predictions for the on-going G7 experiment at JLAB. Finally we discuss that hadron production in nuclei at 10 -20 GeV photon energies can give important information on the hadronization process, and in particular on the time-scales involved. We show here detailed calculations for the low-energy (12 GeV) run at HERMES and predictions for planned experiments at JLAB.

Hadronization in nuclear DIS and ultra-relativistic HIC

“…As we have shown in Ref. [5] our model also successfully describes other aspects of the HERMES data also at beam energy E beam =12 GeV [7]. The rescattering of color neutral prehadrons that are produced early after the initial γ * N interaction seems to be the predominant source for hadron attenuation in cold nuclear matter.…”

“…In our future studies of nuclear DIS we plan to implement a more realistic spacetime picture of hadron production into our model [11] and to investigate in greater detail hadron attenuation in the kinematic regime of the Jefferson ab experiment [7,12].…”

Neutrino–oxygen CC0π scattering in the SuSAv2-MEC model

“…This has triggered intense activity in the nuclear theory community with the goal of describing neutrino-nucleus observables with high accuracy [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. For a detailed and comprehensive study of neutrino-nucleus cross sections and their impact on the measurement of neutrino properties through oscillation experiments, the reader is referred to the NuSTEC White Paper [19] (see also [20]).…”

Neutrino interactions with nuclei

“…In particular, an important prerequisite for any model for the interaction of neutrinos with nuclei is, that it provides a good description of electron-or photon-induced reactions. Within the GiBUU model, extensive tests against existing data are possible and have been successfully performed [2,19,34]…”