Improved Limit on Neutrinoless Double Beta Decay of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Mo</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>100</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math> from AMoRE-I
Aman Agrawal, В. В. Аленков, P. Aryal, J. Beyer, B. Bhandari, R. S. Boiko, K. Boonin, О. А. Бузанов, C. R. Byeon, N. Chanthima, Myung-Ki Cheoun, J. S. Choe, S. Choi, S. Choudhury, Jean S. Chung, F.A. Danevich, Mitra Djamal, D. Drung, C. Enss, A. Fleischmann, A. M. Gangapshev, L. Gastaldo, Yu. M. Gavrilyuk, A. M. Gezhaev, O. Gileva, V. D. Grigorieva, V. Gurentsov, C. Ha, Đặng Hoàng Hà, E. J. Ha, D. H. Hwang, E. J. Jeon, J. A. Jeon, H. S. Jo, J. Kaewkhao, C.S. Kang, W. G. Kang, V. V. Kazalov, Sebastian Kempf, Arshad Khan, S. Khan, D. Y. Kim, G. W. Kim, H. B. Kim, Ho-Jong Kim, H. J. Kim, H. L. Kim, H. S. Kim, M. B. Kim, S. C. Kim, S.K. Kim, S. R. Kim, W. T. Kim, Y.D. Kim, Y. H. Kim, K. Kirdsiri, Y. J. Ko, V. Kobychev, В. Н. Корноухов, V. V. Kuzminov, Duck-Hee Kwon, Cheol Ho Lee, DongYeup Lee, E. K. Lee, H.J. Lee, H. S. Lee, J. Lee, Jooyoung Lee, K. B. Lee, M. H. Lee, M.K. Lee, S. W. Lee, Y. C. Lee, D. S. Leonard, Hong S. Lim, B. Mailyan, E. P. Makarov, P. Nyanda, Y. Oh, S. L. Olsen, S. I. Panasenko, H. Park, H.S. Park, K. S. Park, S.Y. Park, O. G. Polischuk, H. Prihtiadi, S. Ra, S. S. Ratkevich, G. Rooh, E. Sala, M. B. Sari, J. Seo, K. M. Seo, B. Sharma, K. A. Shin, V.N. Shlegel, K. Siyeon, J. H. So, N. V. Sokur
Abstract
AMoRE searches for the neutrinoless double beta decay using 100 kg of enriched ^{100}Mo. Scintillating molybdate crystals coupled with a metallic magnetic calorimeter operate at milli-Kelvin temperatures to measure the energy of electrons emitted in the decay. AMoRE-I is a demonstrator for the full-scale AMoRE, operated at the Yangyang Underground Laboratory for over two years. The exposure was 8.02 kg year (or 3.89 kg_{^{100}Mo} year), and the total background rate near the Q value was 0.025±0.002 counts/keV/kg/year. We observed no indication of 0νββ decay and report a new lower limit of the half-life of ^{100}Mo 0νββ decay as T_{1/2}^{0ν}>2.9×10^{24} yr at 90% confidence level. The effective Majorana mass limit range is m_{ββ}<(210-610) meV using nuclear matrix elements estimated in the framework of different models, including the recent shell model calculations.