Background study of the AMoRE-pilot experiment

• DOI: 10.48550/arxiv.2401.07476
• Publication Date: 2024-10-01
• Authors: A. Agrawal; V.V. Alenkov; P. Aryal; J. Beyer; B. Bhandari; R.S. Boiko; K. Boonin; O. Buzanov; C.R. Byeon; N. Chanthima; M.K. Cheoun; J.S. Choe; Seonho Choi; S. Choudhury; J.S. Chung; F.A. Danevich; M. Djamal; D. Drung; C. Enss; A. Fleischmann; A.M. Gangapshev; L. Gastaldo; Yu.M. Gavrilyuk; A.M. Gezhaev; O. Gileva; V.D. Grigorieva; V.I. Gurentsov; C. Ha; D.H. Ha; 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; S. Kempf; A. 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; Siyeon Kim; W.T. Kim; Y.D. Kim; Y.H. Kim; K. Kirdsiri; Y.J. Ko; V.V. Kobychev; V. Kornoukhov; V.V. Kuzminov; D.H. Kwon; C.H. Lee; DongYeup Lee; E.K. Lee; H.J. Lee; H.S. Lee; J. Lee; J.Y. Lee; K.B. Lee; M.H. Lee; M.K. Lee; S.W. Lee; Y.C. Lee; D.S. Leonard; H.S. Lim; B. Mailyan; E.P. Makarov; P. Nyanda; Y. Oh; S.L. Olsen; S.I. Panasenko; H.K. Park; H.S. Park; K.S. Park; S.Y. Park; O.G. Polischuk; H. Prihtiadi; S. Ra; S.S. Ratkevich; G. Rooh; M.B. Sari; J. Seo; K.M. Seo; B. Sharma; K.A. Shin; V.N. Shlegel; J. So; N.V. Sokur; J.K. Son; J.W. Song; N. Srisittipokakun; V.I. Tretyak; R. Wirawan; K.R. Woo; H.J. Yeon; Y.S. Yoon; Q. Yue
• Keywords: High Energy Physics - Experiment (hep-ex); 0103 physical sciences; FOS: Physical sciences; Nuclear Experiment (nucl-ex); Nuclear Experiment; 01 natural sciences; High Energy Physics - Experiment

We report a study on the background of the Advanced Molybdenum-Based Rare process Experiment (AMoRE), a search for neutrinoless double beta decay (\znbb) of $^{100}$Mo. The pilot stage of the experiment was conducted using $\sim$1.9 kg of \CAMOO~ crystals at the Yangyang Underground Laboratory, South Korea, from 2015 to 2018. We compared the measured $β/γ$ energy spectra in three experimental configurations with the results of Monte Carlo simulations and identified the background sources in each configuration. We replaced several detector components and enhanced the neutron shielding to lower the background level between configurations. A limit on the half-life of $0νββ$ decay of $^{100}$Mo was found at $T_{1/2}^{0ν} \ge 3.0\times 10^{23}$ years at 90\% confidence level, based on the measured background and its modeling. Further reduction of the background rate in the AMoRE-I and AMoRE-II are discussed.