Prospects for relic neutrino detection using nuclear spin experiments
Yeray Garcia del Castillo (Sydney Consortium for Particle Physics and Cosmology School of Physics, The University of New South Wales, Sydney New South Wales 2052, Australia)
; Giovanni Pierobon (Sydney Consortium for Particle Physics and Cosmology School of Physics, The University of New South Wales, Sydney New South Wales 2052, Australia); Dipan Sengupta (Sydney Consortium for Particle Physics and Cosmology School of Physics, The University of New South Wales, Sydney New South Wales 2052, Australia); Yvonne Y.Y. Wong (Sydney Consortium for Particle Physics and Cosmology School of Physics, The University of New South Wales, Sydney New South Wales 2052, Australia)
Direct detection of the cosmic neutrino background () remains one of the most formidable experimental challenges in modern physics. In this work, we extend recent studies of coherent transitions in polarized nuclear spin ensembles. Adopting an open quantum system framework, we model coherent neutrino effects in large spin ensembles using a Lindblad master equation that also incorporates realistic experimental imperfections such as local dephasing and imperfect polarization. We solve the Lindblad equation numerically by way of a fast and computationally inexpensive method that can be extended to an arbitrarily large number of spins. Using our numerical solutions, we forecast the sensitivities of future experiments such as CASPEr to the local overdensity parameter . Our findings indicate that a CASPEr-like experiment, though primarily aimed at axion dark matter search, could also constrain the overdensity to in configurations achievable by currently planned experimental efforts, and down to in the most optimized scenario. While detection remains out of reach in the foreseeable future, our results highlight the potential of using quantum sensing to probe fundamental physics.
