2026/06/16 by Fumiya Oura, Yudai Ichikawa, Junko Yamagata-Sekihara +32
#nucl-ex #nucl-th
We investigated the K-nucleus interaction through the simultaneous measurement of the inclusive 12\rm C(K-, p) and exclusive K--escape 12\rm C(K-, p K-esc) reactions at 1.8 GeV/c at J-PARC. The present measurement explicitly focuses on the K- escape process for the first time, successfully accomplishing a direct experimental determination of the imaginary part of the K- optical potential. The differential cross section for the K--escape reaction was determined to be 436 ± 6 (stat.) ± 44 (syst.)~μb/sr. A simultaneous likelihood fit yielded real and imaginary potential strengths of V0 = -72 +3-5 (stat.) +0-8 (syst.)~MeV and W0 = -100 +7-1 (stat.) +0-16 (syst.)~MeV at the nuclear center, respectively. The derived W0 is significantly stronger than that predicted by theoretical models based on one-nucleon processes, suggesting possible contribution of multi-nucleon involving processes.