Enhanced radiative strength in the quasi-continuum of 117Sn

TL;DR

This paper reports the measurement of radiative strength functions in 117Sn, revealing a resonance-like enhancement in the quasi-continuum region below neutron separation energy, which challenges standard models.

Contribution

It provides the first measurement of the resonance-like structure's functional form in an odd tin nucleus below neutron threshold.

Findings

Significant enhancement of radiative strength function between 4.5 and 8.0 MeV.

Observation of a resonance-like structure in the quasi-continuum region.

First measurement of this structure's form in an odd nucleus below neutron threshold.

Abstract

Radiative strength functions of 117Sn has been measured below the neutron separation energy using the (3He,3He'gamma) reactions. An increase in the slope of the strength functions around E_gamma= 4.5 MeV indicates the onset of a resonance-like structure, giving a significant enhancement of the radiative strength function compared to standard models in the energy region 4.5 <= E_gamma <= 8.0 MeV. For the first time, the functional form of this resonance-like structure has been measured in an odd tin nucleus below neutron threshold in the quasi-continuum region.