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We developed the quasi-particle random phase approximation (QRPA) for the neutrino scattering off even-even nuclei via neutral current (NC) and charged current (CC). The QRPA has been successfully applied for the β and ββ decay of relevant nuclei. To describe neutrino scattering, general multipole transitions by weak interactions with a finite momentum transfer are calculated for NC and CC reaction with detailed formalism. Since we consider neutron-proton (np) pairing as well as neutron-neutron (nn) and proton-proton (pp) pairing correlations, the nn + pp QRPA and np QRPA are combined in a framework, which enables to describe both NC and CC reactions in a consistent way. Numerical results for ν− 12 C, − 56 Fe and − 56 Ni reactions are shown to comply with other theoretical calculations and reproduce well available experimental data.

We calculated neutrino reactions on 40 Ar for detecting core-collapsing supernovae (SNe) neutrinos. The nucleus was originally exploited to identify the solar neutrino emitted from 8 B produced in pp chains on the Sun. With the higher energy neutrinos emitted from the core-collapsing SNe, contributions from higher multipole transitions, as well as from the Gamow-Teller and Fermi transitions, are shown to be important ingredients for understanding reactions induced by the SN neutrino. Moreover, higher excited states beyond a few states known in experiment diminish significantly the expected large difference between the cross sections of ν e andν e reactions on 40 Ar, which difference is anticipated because of the large Q value in theν e reaction. The reduction is shown to lead to a difference between them of only a factor of 2.Neutrino reactions on 40 Ar are of astrophysical importance because the reactions are used to detect the solar neutrino emitted from 8 B in the Sun through the liquid argon time projection chamber (LArTPC) in ICARUS (Imaging of Cosmic and Rare Underground Signals) [1]. Since the maximum energy of the solar neutrino is thought to be about 17 MeV in the standard solar model, the neutrino reactions are sensitive to discrete energy states of 40 Ar. The Q value for the 40 Ar(ν e ,e − ) 40 K * reaction is 1.50 MeV, while it is 7.48 MeV for the 40 Ar(ν e ,e + ) 40 Cl * reaction. Moreover, in 40 Cl * only two excited states for the Gamow-Teller (GT) transition are known with no excited isobaric analog states. Therefore, the 40 Ar(ν e ,e + ) 40 Cl * reaction might be kinematically disfavored in the solar neutrino. In this respect, 40 Ar was claimed to effectively distinguish the ν e andν e emitted from the Sun.Recently, Ref.[2] revised previous work [3] by focusing on the possible detection of neutrino oscillation of supernova (SN) neutrinos. The SN neutrinos may give valuable information about neutrino properties, such as the ν mixing angle θ 13 and the mass hierarchy, because they traverse regions of dense matter in the exploding star where matter-enhanced oscillations take place.One possible way to extract such information is to investigate the abundances of light nuclei, 7 Li and 11 B, which are abundantly produced through the ν process, that is, ν-induced reactions on related nuclei in core-collapsing SNe [4,5]. Since the ν-induced reaction might be sensitive to the ν properties as well as ν flavors, their abundances could be sensitive to the ν parameters.Another way is to directly detect the ν signals coming from core-collapsing SN explosions on the Earth through the LArTPC detector [6]. This ICARUS-like detector is also planned to detect the neutrino beam at CERN [7].Since neutrino energies from SN explosions are expected to be higher than those stemming from the solar neutrino [4,5], one needs to consider the contributions from higher multipole * Corresponding author: cheoun@ssu.ac.kr transitions. Random phase approximation (RPA) calculations [2,3,8] showed that contributions from higher mult...

The advanced molybdenum-based rare process experiment (AMoRE) aims to search for neutrinoless double beta decay ($$0\nu \beta \beta $$0νββ) of $$^{100}$$100Mo with $$\sim 100\,\hbox {kg}$$∼100kg of $$^{100}$$100Mo-enriched molybdenum embedded in cryogenic detectors with a dual heat and light readout. At the current, pilot stage of the AMoRE project we employ six calcium molybdate crystals with a total mass of 1.9 kg, produced from $$^{48}$$48Ca-depleted calcium and $$^{100}$$100Mo-enriched molybdenum ($$^{48{{\text {depl}}}}\hbox {Ca}^{100}\hbox {MoO}_{4}$$48deplCa100MoO4). The simultaneous detection of heat (phonon) and scintillation (photon) signals is realized with high resolution metallic magnetic calorimeter sensors that operate at milli-Kelvin temperatures. This stage of the project is carried out in the Yangyang underground laboratory at a depth of 700 m. We report first results from the AMoRE-Pilot $$0\nu \beta \beta $$0νββ search with a 111 kg day live exposure of $$^{48{{\text {depl}}}}\hbox {Ca}^{100}\hbox {MoO}_{4}$$48deplCa100MoO4 crystals. No evidence for $$0\nu \beta \beta $$0νββ decay of $$^{100}$$100Mo is found, and a upper limit is set for the half-life of $$0\nu \beta \beta $$0νββ of $$^{100}$$100Mo of $$T^{0\nu }_{1/2} > 9.5\times 10^{22}~\hbox {years}$$T1/20ν>9.5×1022years at 90% C.L. This limit corresponds to an effective Majorana neutrino mass limit in the range $$\langle m_{\beta \beta }\rangle \le (1.2-2.1)\,\hbox {eV}$$⟨mββ⟩≤(1.2-2.1)eV.

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