Search for charge non-conserving processes in 127I by coincidence technique

The European Physical Journal C

F. Cappella¹  A. Incicchitti¹  A. d’Angelo¹  S. d’Angelo²  P. Belli²  R. Bernabei²  A. Di Marco²  F. Montecchia³  R. G. Wang⁴  C. J. Dai⁴  X. H. Ma⁴  X. D. Sheng⁴  H. L. He⁴  Z. P. Ye⁵  R. Cerulli⁶ 

[1] Dip. di Fisica, Università di Roma “La Sapienza”, 00185, Rome, Italy;INFN, sez. Roma, 00185, Rome, Italy;Dip. di Fisica, Università di Roma “Tor Vergata”, 00133, Rome, Italy;INFN, sez. Roma “Tor Vergata”, 00133, Rome, Italy;Dip. di Fisica, Università di Roma “Tor Vergata”, 00133, Rome, Italy;INFN, sez. Roma “Tor Vergata”, 00133, Rome, Italy;Lab. Sperim. Policentrico di Ingegneria Medica, Università di Roma “Tor Vergata”, 00133, Rome, Italy;IHEP, Chinese Academy, P.O. Box 918/3, 100039, Beijing, China;IHEP, Chinese Academy, P.O. Box 918/3, 100039, Beijing, China;University of Jing Gangshan, Ji’an, Jiangxi, China;Laboratori Nazionali del Gran Sasso, INFN, Assergi, Italy;

关键词: Excited Level;    Lepton Sector;    Atomic Shell;    Lifetime Limit;    Internal Electron Conversion;   

DOI  :  10.1140/epjc/s10052-012-1920-6

来源: Springer

【 摘 要 】

New lifetime limits on the charge non-conserving (CNC) electron capture with excitation of the 417.9 keV nuclear level in the 127I are established by using the coincidence technique. The analysed exposure is 0.87 ton × yr, collected deep underground at the Gran Sasso National Laboratory of the INFN by the highly radiopure DAMA/LIBRA setup (≈250 kg of highly radiopure NaI(Tl)). The new limit on the mean life is τ>1.2×1024 yr (90 % C.L.), about one order of magnitude larger than those previously available for CNC electron capture involving nuclear level excitations of 127I and of the same order of magnitude than those achieved for analogous processes in 129Xe.

【 授权许可】

CC BY