Probing the absolute neutrino mass scale with 163Ho: The HOLMES project

De Gerone, M.; Alpert, B.; Becker, D.; Bennett, D.; Biasotti, M.; Ceriale, V.; Dressler, R.; Faverzani, M.; Ferri, E.; Fowler, J.; Gallucci, G.; Gard, J.; Gatti, F.; Giachero, A.; Hays-Wehle, J.; Heinitz, S.; Hilton, G.; Koester, U.; Lusignoli, M.; Mates, J.; Nucciotti, A.; Nisi, S.; Orlando, A.; Pessina, G.; Puiu, A.; Ragazzi, S.; Reintsema, C.; Ribeiro Gomes, M.; Schmidt, D.; Schumann, D.; Swetz, D.; Ullom, J.; Vale, L.

doi:10.1016/j.nima.2018.10.108

The HOLMES project aims to directly measure the nu mass down to the eV scale using the electron capture decay (EC) of Ho-163. It will perform a precise calorimetric measurement of the end-point of the Ho energy spectrum looking for the deformation caused by a finite nu mass. The choice of Ho-163 as source is driven by the very low Q-value of the EC reaction, which allows for high sensitivity with low activities (O(10(2))Bq/detector), thus reducing the pile-up probability. A large array made by thousands of transition edge sensors based micro-calorimeters will be used. The calorimetric approach eliminates systematic uncertainties arising from the use of an external beta source, and minimizes the effect of the atomic de-excitation process. The commissioning of the first implanted sub-array is scheduled for the end of 2018. It will provide useful data about the EC decay of Ho-163 together with a first limit on nu mass.

Probing the absolute neutrino mass scale with 163Ho: The HOLMES project

De Gerone M.;Alpert B.;Becker D.;Bennett D.;Biasotti M.;Ceriale V.;Dressler R.;Faverzani M.;Ferri E.;Fowler J.;Gallucci G.;Gard J.;Gatti F.;Giachero A.;Hays-Wehle J.;Heinitz S.;Hilton G.;Koester U.;Lusignoli M.;Mates J.;Nucciotti A.;Nisi S.;Orlando A.;Pessina G.;Puiu A.;Ragazzi S.;Reintsema C.;Ribeiro Gomes M.;Schmidt D.;Schumann D.;Swetz D.;Ullom J.;Vale L.

2019-01-01

Abstract

The HOLMES project aims to directly measure the nu mass down to the eV scale using the electron capture decay (EC) of Ho-163. It will perform a precise calorimetric measurement of the end-point of the Ho energy spectrum looking for the deformation caused by a finite nu mass. The choice of Ho-163 as source is driven by the very low Q-value of the EC reaction, which allows for high sensitivity with low activities (O(10(2))Bq/detector), thus reducing the pile-up probability. A large array made by thousands of transition edge sensors based micro-calorimeters will be used. The calorimetric approach eliminates systematic uncertainties arising from the use of an external beta source, and minimizes the effect of the atomic de-excitation process. The commissioning of the first implanted sub-array is scheduled for the end of 2018. It will provide useful data about the EC decay of Ho-163 together with a first limit on nu mass.