Behavior of the Be and C total photonuclear cross section in the nucleon resonance region

Abstract

We present the total photonuclear cross section for Be and C measured between 200 and 1100 MeV, with the aim of clarifying the existence of a resonant behavior in the region above the Δ. We used a tagged photon beam and the transmission technique. The results show no evidence of baryon resonances that are clearly seen at ≊700 and ≊1000 MeV in photon absorption on the proton and the deuteron

Nuclear photoproduction of vector mesons within a Monte Carlo approach

“…The second term at the right-hand side of Eq. (2) corresponds to the f -Reggeon contribuition and is given by [57] f z,t,M 2…”

“…The photoabsorption process allows the study of the formation and propagation of several particles inside nuclear matter, such as baryonic resonances and hyperons [1][2][3][4][5][6]. It is also useful to observe the shadowing effect in the photoabsorption cross section, which is the result of the hadronization process of photons in the nuclear medium.…”

Photofission of235U and238U at intermediate energies: absolute cross sections and fragment mass distributions

“…The most striking result, seen for the first time in the Mainz experiments [20], was the fact that, in contrast to the free proton, in the energy region of the D13-resonance near 710 MeV no resonance-like structure could be observed. The complete suppression of the D13-resonance in the nuclear medium in contrast to the behaviour of the first baryon resonance, the well studied A-resonance, has in the meantime been observed not only in the heavy Uranium isotopes by other experimentalists but also in the light nuclei 9Be and ]2C using quite different techniques [21,22,23]. The mechanism of the broadening and/or damping of the higher baryon resonances is currently only explained using phenomenological descriptions.…”

“…The same effect recently has been observed in light nuclei. Using the photon attenuation technique Anghinolfi et al [23] measured at Frascati the total absorption cross sections for 9Be and 12C and found n_s resonance-like structures at the energies of the D13 and F15 resonances. In these experiments the absolute normalization of the cross section was obtained by adjusting the values to previous data in the well studied A-resonance region.…”

“…In Frascati photon absorption cross sections were investigated for the nuclei 9Be, 12C and 238U using different techniques in the extended energy range of 200 MeV< E. r < 1200 MeV (see Sect. 4) [21,22,23].…”