Multipole-Resolved Nuclear Transition Strengths of 12C Induced by Mono-Energetic KDAR Neutrinos

Abstract

Mono-energetic neutrinos from kaon decay at rest (KDAR) provide a unique opportunity to investigate nuclear weak transition strengths under fixed kinematic conditions. In this work, we study charged-current KDAR neutrino-induced reactions on 12C at an incident energy of E nu similar or equal to 236 MeV, focusing on a multipole-resolved analysis of nuclear transition strengths. The transition strengths are decomposed according to spin and parity, and separated into longitudinal and transverse components as well as vector and axial-vector contributions. In particular, the multipole dependence reveals a clear transition from collective to single-nucleon dynamics with increasing excitation energy. The present results demonstrate that KDAR neutrino-induced reactions provide direct access to multipole-dependent nuclear transition strengths that are otherwise difficult to isolate in flux-averaged measurements.