TY - JOUR
T1 - Probing invisible neutrino decay with the first six detection units of KM3NeT/ORCA
AU - the KM3NeT Collaboration
AU - Aiello, S.
AU - Albert, A.
AU - Alhebsi, A. R.
AU - Alshamsi, M.
AU - Alves Garre, S.
AU - Ambrosone, A.
AU - Ameli, F.
AU - Andre, M.
AU - Aphecetche, L.
AU - Ardid, M.
AU - Ardid, S.
AU - Aublin, J.
AU - Badaracco, F.
AU - Bailly-Salins, L.
AU - Bardačová, Z.
AU - Baret, B.
AU - Bariego-Quintana, A.
AU - Becherini, Y.
AU - Bendahman, M.
AU - Benfenati Gualandi, F.
AU - Benhassi, M.
AU - Bennani, M.
AU - Benoit, D. M.
AU - Berbee, E.
AU - Bertin, V.
AU - Biagi, S.
AU - Boettcher, M.
AU - Bonanno, D.
AU - Bouasla, A. B.
AU - Boumaaza, J.
AU - Bouta, M.
AU - Bouwhuis, M.
AU - Bozza, C.
AU - Bozza, R. M.
AU - Brânzaş, H.
AU - Bretaudeau, F.
AU - Breuhaus, M.
AU - Bruijn, R.
AU - Brunner, J.
AU - Bruno, R.
AU - Buis, E.
AU - Buompane, R.
AU - Busto, J.
AU - Caiffi, B.
AU - Calvo, D.
AU - Capone, A.
AU - Carenini, F.
AU - Carretero, V.
AU - Cartraud, T.
AU - Razzaque, S.
N1 - Publisher Copyright:
© The Author(s) 2025.
PY - 2025/4
Y1 - 2025/4
N2 - In the era of precision measurements of neutrino oscillation parameters, it is necessary for experiments to disentangle discrepancies that may indicate physics beyond the Standard Model in the neutrino sector. KM3NeT/ORCA is a water Cherenkov neutrino detector under construction and anchored at the bottom of the Mediterranean Sea. The detector is designed to study the oscillations of atmospheric neutrinos and determine the neutrino mass ordering. This paper focuses on the initial configuration of ORCA, referred to as ORCA6, which comprises six out of the foreseen 115 detection units of photosensors. A high-purity neutrino sample was extracted during 2020 and 2021, corresponding to an exposure of 433 kton-years. This sample is analysed following a binned log-likelihood approach to search for invisible neutrino decay, in a three-flavour neutrino oscillation scenario, where the third neutrino mass state ν3 decays into an invisible state, e.g. a sterile neutrino. The resulting best fit of the invisible neutrino decay parameter is α3=0.92−0.57+1.08×10−4 eV2, corresponding to a scenario with θ23 in the second octant and normal neutrino mass ordering. The results are consistent with the Standard Model, within a 2.1 σ interval.
AB - In the era of precision measurements of neutrino oscillation parameters, it is necessary for experiments to disentangle discrepancies that may indicate physics beyond the Standard Model in the neutrino sector. KM3NeT/ORCA is a water Cherenkov neutrino detector under construction and anchored at the bottom of the Mediterranean Sea. The detector is designed to study the oscillations of atmospheric neutrinos and determine the neutrino mass ordering. This paper focuses on the initial configuration of ORCA, referred to as ORCA6, which comprises six out of the foreseen 115 detection units of photosensors. A high-purity neutrino sample was extracted during 2020 and 2021, corresponding to an exposure of 433 kton-years. This sample is analysed following a binned log-likelihood approach to search for invisible neutrino decay, in a three-flavour neutrino oscillation scenario, where the third neutrino mass state ν3 decays into an invisible state, e.g. a sterile neutrino. The resulting best fit of the invisible neutrino decay parameter is α3=0.92−0.57+1.08×10−4 eV2, corresponding to a scenario with θ23 in the second octant and normal neutrino mass ordering. The results are consistent with the Standard Model, within a 2.1 σ interval.
KW - Beyond Standard Model
KW - Neutrino Detectors and Telescopes (experiments)
KW - Oscillation
UR - https://www.scopus.com/pages/publications/105006450029
U2 - 10.1007/JHEP04(2025)105
DO - 10.1007/JHEP04(2025)105
M3 - Article
AN - SCOPUS:105006450029
SN - 1126-6708
VL - 2025
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
IS - 4
M1 - 105
ER -