Probing the absolute neutrino mass scale with $^{163}$Ho: The HOLMES project

M. de Gerone , B. Alpert , D. Becker , D. Bennett , M. Biasotti , V. Ceriale , R. Dressler , M. Faverzani , E. Ferri , J. Fowler , G. Gallucci , J. Gard , F. Gatti , A. Giachero , J. Hays-Wehle , S. Heinitz , G. Hilton , U. Koester (1) , M. Lusignoli , J. Mates , A. Nucciotti , S. Nisi , A. Orlando , G. Pessina , A. Puiu , S. Ragazzi , C. Reintsema , M. Ribeiro Gomes , D. Schmidt , D. Schumann , D. Swetz , J. Ullom , L. Vale

1 ILL - Institut Laue-Langevin

The HOLMES project aims to directly measure the ν mass down to the eV scale using the electron capture decay (EC) of 163 Ho. It will perform a precise calorimetric measurement of the end-point of the Ho energy spectrum looking for the deformation caused by a finite ν mass. The choice of 163 Ho 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 β 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 163 Ho together with a first limit on ν mass.

Mots clés: Neutrino mass measurement; Electron capture; Holmium; Transition edge sensors; activity report; neutrino: mass; electron: capture; calorimeter; HOLMES; sensitivity; pile-up; holmium: nuclide

Domaines: Instrumentations et Détecteurs [physics.ins-det]

M. de Gerone, B. Alpert, D. Becker, D. Bennett, M. Biasotti, et al.. Probing the absolute neutrino mass scale with $^{163}$Ho: The HOLMES project. 14th Pisa Meeting on Advanced Detectors, May 2018, La Biodola-Isola d'Elba, Italy. pp.252-253, ⟨10.1016/j.nima.2018.10.108⟩. ⟨hal-02188873⟩