Formation of eta-prime(958)-mesic nuclei by (p,d) reaction

TL;DR

This paper theoretically investigates the formation of eta'-mesic nuclei via (p,d) reactions, predicting observable peak structures indicating eta'-nucleus attraction, and discusses experimental feasibility and background contributions.

Contribution

It provides a theoretical framework and numerical calculations for eta'-mesic nuclei formation spectra in (p,d) reactions, highlighting conditions for observable signals and experimental considerations.

Findings

Peak structures around eta' threshold suggest attractive eta'-nucleus interaction.

Potential depths greater than 100 MeV produce detectable signals.

Contributions from omega and phi mesons do not obscure eta' signals.

Abstract

We calculate theoretically the formation spectra of eta'(958)-nucleus systems in the (p,d) reaction for the investigation of the in-medium modification of the eta' mass. We show the comprehensive numerical calculations based on a simple form of the eta' optical potential in nuclei with various potential depths. We conclude that one finds an evidence of possible attractive interaction between eta' and nucleus as peak structure appearing around the eta' threshold in light nuclei such as 11C when the attractive potential is stronger than 100 MeV and the absorption width is of order of 40 MeV or less. Spectroscopy of the (p,d) reaction is expected to be performed experimentally at existing facilities, such as GSI. We also estimate the contributions from the omega and phi mesons, which have masses close to the eta' meson, concluding that the observation of the peak structure of the eta'-mesic nuclei is not disturbed although their contributions may not be small.