科研之友
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摘要
In this paper, we calculate the QCD nonperturbative contributions of the neutrino-quark tensor operators to the neutrino magnetic moments by matching onto the chiral perturbation theory at low energies. These nonperturbative contributions can be compared to the perturbative ones, which are induced from one-loop mixing when performing the renormalization group evolutions from mu = mW down to mu = 2 GeV. We then constrain the dipole and tensor Wilson coefficients of the low-energy neutrino effective field theory (LNEFT) separately from the neutrino-electron scattering with Borexino data and coherent elastic neutrino -nucleus scattering (CEvNS) with COHERENT data to show the competition between these two contributions, at the renormalization scales mu = 2 GeV and mu = mW in the MS scheme. In the neutrino-electron scattering, it is found that the nonperturbative contributions dominate for the coefficients involving up and down quarks, while they are expected to be of the same order of magnitude as the perturbative contributions for the coefficients involving strange quarks. As for constraints in the CEvNS, the tensor operators can contribute to the process through either direct or indirect ways. As a result, the indirect contributions including nonperturbative and perturbative parts for all couplings become negligible in comparison to the direct ones. As the nonperturbative contributions crucially depend on the value of cT, its inputs will affect the extraction of limits on the tensor LNEFT Wilson coefficients. We compute the upper bounds on these coefficients with cT quoting from the model and lattice estimates.
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单位中山大学
