Momentum-dependent contributions to the gravitational coupling of neutrinos in a medium

Abstract

When neutrinos travel through a normal matter medium, the electron neutrinos couple differently to gravity compared to the other neutrinos, due to the presence of electrons in the medium and the absence of the other charged leptons. We calculate the momentum-dependent part of the matter-induced gravitational couplings of the neutrinos under such conditions, which arise at order $g^2/M_W^4$, and determine their contribution to the neutrino dispersion relation in the presence of a gravitational potential ${\varphi }^{\mathrm{ext}}$. These new contributions vanish for the muon and tau neutrinos. For electron neutrinos with momentum $K$, they are of the order of the usual Wolfenstein term times the factor $(K^2/M_W^2){\varphi }^{\mathrm{ext}}$, for high energy neutrinos. In environments where the gravitational potential is substantial, such as those in the vicinity of Active Galactic Nuclei, they could be the dominant term in the neutrino dispersion relation. They must also be taken into account in the analysis of possible violations of the Equivalence Principle in the neutrino sector, in experimental settings involving high energy neutrinos traveling through a matter background.

Minor corrections in the references; one reference added

References in corpus (4)

• Testing violations of special and general relativity through the energy dependence of nu_mu<--->nu_tau oscillations in the Super-Kamiokande atmospheric neutrino experiment
• Constraints on Exotic Mixing of Three Neutrinos
• Matter effects on neutrino oscillations in gravitational and magnetic fields
• Non-universal gravitational couplings of neutrinos in matter

Cited by in corpus (5)

• Gravitational decay of the Z-boson
• Interaction of Dirac and Majorana Neutrinos with Weak Gravitational Fields
• Perturbative vs Schwinger-propagator method for the calculation of amplitudes in a magnetic field
• Angular momentum non-conserving decays in isotropic media
• Neutrino gravitational decay in a medium