FisMat2017 - Submission - View

Abstract's title: Direct calorimetric measurement of the neutrino mass with HOLMES
Submitting author: Marco Faverzani
Affiliation: Università Milano Bicocca & INFN Milano Bicocca
Affiliation Address: Piazza della Scienza, 3 20126 Milano
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Bradley Alpert (NIST), Marco Balata (INFN - LNGS), Daniel Becker (NIST), Douglas Bennet (NIST), Adriano Bevilacqua (INFN - Genova), Michele Biasotti (INFN - Genova), Valentina Ceriale (INFN - Genova), Giancarlo Ceruti (INFN - Milano Bicocca), Matteo DeGerone (INFN - Genova), Rugard Dresser (PSI), Elena Ferri (INFN - Milano Bicocca), Joseph Fowler (NIST), Giovani Gallucci (INFN - Genova), John Gard (NIST), Flavio Gatti (INFN - Genova), Andrea Giachero (INFN - Milano Bicocca), James Hays-Wehle (NIST), Stephan Heinitz (PSI), Gene Hilton (NIST), Ulli Koester (ILL), Maurizio Lusignoli (INFN - Roma 1), John Mates (NIST), Stefano Nisi (INFN - LNGS), Angelo Nucciotti (Università di Milano Bicocca), Angiola Orlando (INFN - Milano Bicocca), Luigi Parodi (INFN - Genova), Gianluigi Pessina (INFN - Milano Bicocca), Andrei Puiu (Università di Milano Bicocca), Stefano Ragazzi (Università di Milano Bicocca), Carl Reintsema (NIST), Maria Ribeiro-Gomes (CENTRA-IST), Dan Schmidt (NIST), Dorothea Schumann (PSI), Fabio Siccardi (INFN - Genova), Daniel Swetz (NIST), Joel Ullom (NIST), Leila Vale (NIST)

Measuring the neutrino mass is one the most compelling issues in modern particle physics. HOLMES experiment aims at directly measuring the neutrino mass with a sensitivity as low as 1 eV exploiting the calorimetric approach: HOLMES will extract information on neutrino mass through a precise measurement of the end-point of the Electron Capture decay spectrum of 163Ho. HOLMES, in its final configuration, will deploy a 1000-pixel array of low temperature microcalorimeters: each detector is composed of a gold absorber, where the 163Ho nuclei will be ion implanted, coupled to a Transition Edge Sensor which acts as thermometer. The detectors will be kept at their operating temperature of 70 mK in a dilution refrigerator. In order to easily read out the 1000 detectors of HOLMES, a multiplexed readout is required: the choice is to couple the Transition Edge Sensors to multiplexed rf-SQUIDs operated in flux ramp modulation for linearization purposes. The rf-SQUIDs, in turn, are coupled to superconducting quarter wavelength resonators in the GHz range, from which the modulated signal is finally recovered using Software-Defined Radio techniques. This allows to readout multiple detectors with a common readout line, heavily simplifying the experimental set-up.

In this contribution, we outline the status and perspective of HOLMES: the target time and energy resolution have been reached while the final detector array design is being finalized. A first 64 detectors measurement is planned to start by the beginning of 2018: this will allow to evaluate crucial parameters, such as the relevance of shake-up and shake-off second order processes, which could be relevant in affecting the spectral shape close to the end-point. From this preliminary measurement, with a two-month long exposure time, it will be possible to set a limit below 10 eV on the neutrino mass.