Speaker
Description
Superfluid He-4 can serve as a tool for neutrino [1] and dark matter detection [2]. Low-energy neutrino interaction with superfluid He-4 can take place in the form of coherent elastic neutrino-atom scattering (CEvAS) [3] - a process that has not been observed so far. The first experimental study of CEvAS is under preparation in the National Center for Physics and Mathematics in Sarov [4]. Using a high-intensity tritium neutrino source and a superfluid He-4 detector, it will have a rich potential to test the neutrino physics of Standard Model and beyond it at unprecedentedly low energies. For example, one of the observable effects of beyond-Standard-Model physics in CEvAS can be neutrino millicharge and magnetic moment [5]. In our work we develop a theoretical approach for studying neutrino interaction with a superfluid He-4 by taking into account single quasiparticle production in a superfluid He-4 target upon tritium neutrino scattering. In particular, we show that such collective effects drastically influence the neutrino scattering cross section at energy transfer of the order of 1 meV and less.
[1] R.E. Lanou, H.J. Maris, and G.M. Seidel, Detection of solar neutrinos in superfluid helium, Phys. Rev. Lett. 58 (1987) 2498.
[2] You, Y., Smolinsky, J., Xue, W., Matchev, K., Saab, T., Gunther, K., and Lee, Y. Signatures and detection prospects for sub-GeV dark matter with superfluid helium. JHEP 2023(7) (2023) 1-31.
[3] M. Cadeddu, F. Dordei, C. Giunti, K. Kouzakov, E. Picciau and A. Studenikin, Potentialities of a low-energy detector based on 4He evaporation to observe atomic effects in coherent neutrino scattering and physics perspectives, Phys. Rev. D 100 (2019) no.7, 073014 [arXiv:1907.03302 [hep-ph]].
[4] А.А. Yukhimchuk, А.N. Golubkov, I.P. Maximkin, et al., Physics of hydrogen isotopes, FIZMAT 1 (2023) 5 (in Russian).
[5] G. Donchenko, K. Kouzakov, and A. Studenikin, Elastic neutrino-atom scattering as a probe of neutrino millicharge and magnetic moment, JETP Lett. 117 (2023) 879.
