Search for Exotic Nuclear Ultra-Rare Process and Ultra-Lowbackground Nuclear Spectroscopy

The nuclear exotic ultra-rare decays and The possibility of The exotic particles havebeen investigated by means of ultra rare过程核spectroscopy with ultra low backgrounddetectors. Abstracts studied are as follows:1. Super heavy charged particle X- have been searchedby using ^<100>Mo nucleus. We studied the exotic nuclear beta decay ^<100>MoX^- -> ^<100>TcX^- ->RuX -. The exotic decay was studied by using ultra low background Ge detector. The upper limitof the creation of such exotic nucleus ^<100>MoX^- is found to be 2.84.10^<-26> 1/sec/nucleus.2.The charge non-conserving processes (CNC) were studied by exotic CNC beta decay of <100>Mo^<100>Tc+nu+ nu (a) and the CNC nuclear excitation of ^<127>I+ e_k ->^< 127>I^*+nu (b). thepossibility of the process (a) was investigated by measuring gamma-ray of the doughter of ^<100>Tc.The lower limit of The CNC beta decay is 1.1 . 10 <18>yr，which means the upper limit of the CNC coupling constant *^2_*(g_ < CNC…More >/ g_f)^2<2.3 / 10^<-20>. The CNC过程(b) was studied by searching for The gamma decayfrom the first excited state of ^<127>I. Lower lirffit of the mean life was obtained 5.8 . 10^<23>yr，which means the upper limit of the coupling constant *^2_* (g_ <cnc>/ g_f)^2 < 1.1 / 10^<-24>.3. Darkmatter (DM) if there is in our galaxy，may interact to a nucleus in the detector via elastic collision. An ultralow background large volumeNaI detector was used to search DAI candidates. As both <23>Na and ^<127>I nucleus in the NaIdetector has a nonzero spin，NaI detector is very suitable to search for the DM candidates with only axdal vector couplings。addition,the cross section of DM candidates with spin independent couplings is roughly proportional to thethe square of the neutron number<127>I nucleus is very effective to the detection of DM candidates with spin independent couplings。pulse height effect of The recoil nucleon due to The DM scattering in The NaI detector have之前直接measured by using neutron scattering. Our data shows the most stringent upper limit onthe maximum halo density of the both candidate of Dirac neutrino and Majorana neutrino with massheavier than about 10OGeV. Less

The nuclear exotic ultra-rare decays and the possibility of the existence of exotic particles have been investigated by means of ultra rare process nuclear spectroscopy with ultra low background detectors. Abstracts studied are as follows :1. Super heavy charged particle X- have been searched by using ^<100>Mo nucleus. We studied the exotic nuclear beta decay ^<100>MoX^- -> ^<100>TcX^- -> ^<100>RuX^-. The exotic decay was studied by using ultra low background Ge detector. The upper limit of the creation of such exotic nucleus ^<100>MoX^- is found to be 2.84.10^<-26> 1/sec/nucleus.2. The charge non-conserving processes (CNC) were studied by exotic CNC beta decay of ^<100>Mo ->^<100>Tc+nu+ nu (a) and the CNC nuclear excitation of ^<127>I+e_K -> ^<127>I^*+nu (b). The possibility of the process (a) was investigated by measuring gamma-ray of the doughter of ^<100>Tc. The lower limit of the CNC beta decay is 1.1・10^<18>yr, which means the upper limit of the CNC coupling constant *^2_*(G_<cnc … More >/G_F)^2<2.3・10^<-20>. The CNC process (b) was studied by searching for the gamma decay from the first excited state of ^<127>I. Lower lirffit of the mean life was obtained 5.8・10^<23>yr, which means the upper limit of the coupling constant *^2_* (G_<cnc>/G_F)^2 < 1.1・10^<-24>.3. Dark matter (DM), if there is in our galaxy, may interact to a nucleus in the detector via elastic collision. An ultralow background large volume NaI detector was used to search DAI candidates. As both ^<23>Na and ^<127>I nucleus in the NaI detector has a nonzero spin, NaI detector is very suitable to search for the DM candidates with only axdal vector couplings. In addition, the cross section of DM candidates with spin independent couplings is roughly proportional to the the square of the neutron number, ^<127>I nucleus is very effective to the detection of DM candidates with spin independent couplings. The pulse height effect of the recoil nucleon due to the DM scattering in the NaI detector have been directly measured by using neutron scattering. Our data shows the most stringent upper limit on the maximum halo density of the both candidate of Dirac neutrino and Majorana neutrino with mass heavier than about 10OGeV. Less