Find in Library
Search millions of books, articles, and more
Indexed Open Access Databases
Search for Double Beta Decay of <sup>106</sup>Cd with an Enriched <sup>106</sup>CdWO<sub>4</sub> Crystal Scintillator in Coincidence with CdWO<sub>4</sub> Scintillation Counters
Autor: Pierluigi Belli, R. Bernabei, V.B. Brudanin, F. Cappella, V. Caracciolo, R. Cerulli, F. A. Danevich, Antonella Incicchitti, D.V. Kasperovych, V.R. Klavdiienko, V.V. Kobychev, Vittorio Merlo, O.G. Polischuk, V.I. Tretyak, M.M. Zarytskyy
Médium: | Article |
---|---|
Vydáno: | MDPI AG 2020-10-01 |
Popis
Studies on double beta decay processes in <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mn>106</mn></msup></semantics></math></inline-formula>Cd were performed by using a cadmium tungstate scintillator enriched in <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mn>106</mn></msup></semantics></math></inline-formula>Cd at 66% (<inline-formula><math display="inline"><semantics><msup><mrow></mrow><mn>106</mn></msup></semantics></math></inline-formula>CdWO<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula>) with two CdWO<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula> scintillation counters (with natural Cd composition). No effect was observed in the data that accumulated over 26,033 h. New improved half-life limits were set on the different channels and modes of the <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mn>106</mn></msup></semantics></math></inline-formula>Cd double beta decay at level of <inline-formula><math display="inline"><semantics><mrow><mo movablelimits="true" form="prefix">lim</mo><msub><mi>T</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>∼</mo><msup><mn>10</mn><mn>20</mn></msup><mo>−</mo><msup><mn>10</mn><mn>22</mn></msup></mrow></semantics></math></inline-formula> yr. The limit for the two neutrino electron capture with positron emission in <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mn>106</mn></msup></semantics></math></inline-formula>Cd to the ground state of <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mn>106</mn></msup></semantics></math></inline-formula>Pd, <inline-formula><math display="inline"><semantics><mrow><msubsup><mi>T</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow><mrow><mn>2</mn><mi>ν</mi><mi>EC</mi><msup><mi>β</mi><mo>+</mo></msup></mrow></msubsup><mo>≥</mo><mn>2.1</mn><mo>×</mo><msup><mn>10</mn><mn>21</mn></msup></mrow></semantics></math></inline-formula> yr, was set by the analysis of the <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mn>106</mn></msup></semantics></math></inline-formula>CdWO<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula> data in coincidence with the energy release 511 keV in both CdWO<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula> counters. The sensitivity approaches the theoretical predictions for the decay half-life that are in the range <inline-formula><math display="inline"><semantics><mrow><msub><mi>T</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>∼</mo><msup><mn>10</mn><mn>21</mn></msup><mo>−</mo><msup><mn>10</mn><mn>22</mn></msup></mrow></semantics></math></inline-formula> yr. The resonant neutrinoless double-electron capture to the 2718 keV excited state of <inline-formula><math display="inline"><semantics><msup><mrow></mrow><mn>106</mn></msup></semantics></math></inline-formula>Pd is restricted at the level of <inline-formula><math display="inline"><semantics><mrow><msubsup><mi>T</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow><mrow><mn>0</mn><mi>ν</mi><mn>2</mn><mi mathvariant="normal">K</mi></mrow></msubsup><mo>≥</mo><mn>2.9</mn><mo>×</mo><msup><mn>10</mn><mn>21</mn></msup></mrow></semantics></math></inline-formula> yr.