Coincidence Measurement of the Nonmesonic Weak Decay of ^{12}_{Lambda}C
Abstract
We have measured the angular correlation of the pair nucleons np and nn emitted from the nonmesonic weak decay (NMWD) of ^{12}_{Lambda}C produced via the (pi^+,K^+) reaction in coincidence measurement. The Lambda p -> np and Lambda n -> nn modes were clearly identified by measuring the back-to-back correlation of the emitted nucleon pairs which is the characteristic of two-body kinematics. From the measured nucleon pair numbers N_{nn} and N_{np}, the ratio Gamma_n/Gamma_p of the partial decay widths Gamma_n(Lambda n -> nn) and Gamma_p(Lambda p -> np) of ^{12}_{Lambda}C was extracted to be 0.51+-0.13(stat) +- 0.05(syst); this result is almost free from the ambiguity due to the nuclear final state interaction and 3-body decay process, which were inherent in the previous results. The obtained Gamma_n/Gamma_p ratio of ^{12}_{Lambda}C (p-shell) is close to that of ^5_{Lambda}He (s-shell). The results are consistent with those of recent theoretical calculations.
Keywords
Cite
@article{arxiv.nucl-ex/0601029,
title = {Coincidence Measurement of the Nonmesonic Weak Decay of ^{12}_{Lambda}C},
author = {M. J. Kim and S. Ajimura and K. Aoki and A. Banu and H. Bhang and T. Fukuda and O. Hashimoto and J. I. Hwang and S. Kameoka and B. H. Kang and E. H. Kim and J. H. Kim and T. Maruta and Y. Miura and Y. Miyake and T. Nagae and M. Nakamura and S. N. Nakamura and H. Noumi and S. Okada and Y. Okayasu and H. Outa and H. Park and P. K. Saha and Y. Sato and M. Sekimoto and S. Shin and T. Takahashi and H. Tamura and K. Tanida and A. Toyoda and K. Tsukada and T. Watanabe and H. J. Yim},
journal= {arXiv preprint arXiv:nucl-ex/0601029},
year = {2009}
}
Comments
13 pages, 4figures, 1 table,re-submitted to Physics Letters B