Mass dependence of inclusive nuclear φ photoproduction

Abstract

Based on a prior determination of the φ selfenergy in a nuclear medium we perform a theoretical study of inclusive φ photoproduction in nuclei, looking at the A dependence of the cross sections for different φ momenta. We find sizeable reductions in the nuclear cross sections with respect to the elementary one, using a φ selfenergy which implies a width about six times the free one at normal nuclear density. The calculations are done to match the set up for an ongoing experiment at SPring8/Osaka which should provide valuable information on the renormalization of the φ properties in nuclei.

Measuring the ϕ meson width in the medium from p induced ϕ production in nuclei

“…Indeed, predictions of an increase of the φ width by a factor five or six [ 2, 3] to ten [ 4], at normal nuclear matter density, have been made using different chiral approaches. Different reactions have been studied or suggested to test experimentally this large width [ 5,6,4,7,8,9].The aim of the present work is to propose a new method to determine the φ width in the nuclear medium [ 10]. The traditional method in the works quoted above (except [ 9]) is to look for a broadening of the φ width reconstructed from the invariant mass of its decay products.…”

“…Different reactions have been studied or suggested to test experimentally this large width [ 5,6,4,7,8,9].…”

“…The traditional method in the works quoted above (except [ 9]) is to look for a broadening of the φ width reconstructed from the invariant mass of its decay products. Here, instead, we use a different philosophy and we investigate the A dependence of φ production in pA collisions, in a similar way as it was done in [ 9] with the φ photoproduction in nuclei, which is the subject of experimental investigation at Spring8/Osaka [ 11].…”

“…Indeed, predictions of an increase of the φ width by a factor five or six [ 2,3] to ten [ 4], at normal nuclear matter density, have been made using different chiral approaches. Different reactions have been studied or suggested to test experimentally this large width [ 5,6,4,7,8,9].…”

“…The traditional method in the works quoted above (except [ 9]) is to look for a broadening of the φ width reconstructed from the invariant mass of its decay products. Here, instead, we use a different philosophy and we investigate the A dependence of φ production in pA collisions, in a similar way as it was done in [ 9] with the φ photoproduction in nuclei, which is the subject of experimental investigation at Spring8/Osaka [ 11]. The advantage of performing the reaction slightly above threshold is that one can rule out the contribution from coherent φ production which might obscure the interpretation of the experimental results in [ 11].…”