Neutron lifetime measurement with pulsed cold neutrons
K. Hirota, Go Ichikawa, S. Ieki, Takashi Ino, Yoshihisa Iwashita, Masaaki Kitaguchi, Ryunosuke Kitahara, Jun Koga, K. Mishima, Tatsushi Mogi, Koji Morikawa, Aya Morishita, Naoki Nagakura, H. Oide, Hirotaka Okabe, H. Otono, Yoshichika Seki, Daiichiro Sekiba, Tatsushi Shima, Hirohiko M. Shimizu, Naoyuki Sumi, Hirochika Sumino, T. Tomita, Haruhiko Uehara, T. Yamada, Shinji Yamashita, Kazumi Yano, Mami Yokohashi, T. Yoshioka
Abstract
Abstract The neutron lifetime has been measured by comparing the decay rate with the reaction rate of $^3$He nuclei of a pulsed neutron beam from the spallation neutron source at the Japan Proton Accelerator Research Complex (J-PARC). The decay rate and the reaction rate were determined by simultaneously detecting electrons from the neutron decay and protons from the $^3$He(n,p)$^3$H reaction using a gas chamber, the working gas of which contains diluted $^3$He. The measured neutron lifetime was $898\,\pm\,10\,_{\rm stat}\,^{+15}_{-18}\,_{\rm sys}\,$s.