Measurement of differential cross sections for elastic scattering in the momentum range 0.44-0.80 GeV/c

Nanamura, Takuya; Fujita, Manami; Hasegawa, Shoichi   ; Ichikawa, Masaya; Ichikawa, Yudai   ; Imai, Kenichi*; Naruki, Megumi; Sato, Susumu  ; Sako, Hiroyuki   ; Tamura, Hirokazu; Tanida, Kiyoshi   ; Yamamoto, Takeshi  ; 59 of others*

We performed a novel scattering experiment at the J-PARC Hadron Experimental Facility. Approximately 2400 elastic scattering events were identified from tagged particles in the momentum range 0.44 - 0.80 GeV/c. The differential cross sections of the elastic scattering were derived with much better precision than in previous experiments. The obtained differential cross sections were approximately 2 mb/sr or less, which were not as large as those predicted by the fss2 and FSS models based on the quark cluster model in the short-range region. By performing phase-shift analyses for the obtained differential cross sections, we experimentally derived the phase shifts of the and channels for the first time. The phase shift of the 3S1 channel, where a large repulsive core was predicted owing to the Pauli effect between quarks, was evaluated to be . If the sign of is assumed to be negative, the interaction in this channel is moderately repulsive, as the Nijmegen extended-sort-core models predicted.