Updated detection prospects for relic neutrinos using coherent scattering

We review the existing proposals to detect relic neutrinos using the coherent scattering of a neutrino wind on a test mass. By considering the transformation of the neutrino momentum between reference frames, we demonstrate that the induced acceleration scales with the square of the neutrino mass for unclustered neutrinos, contrary to the existing literature. In addition, we show that there is a large contribution to this effect from coherent neutrino-electron scattering, which can exceed the neutrino-nucleus component by nearly an order of magnitude. Unfortunately, we find that even with this enhancement there are no existing experiments or proposals capable of detecting relic neutrinos using this method.

THE SUPERLUMINAL NEUTRINOS FROM DEFORMED LORENTZ INVARIANCE

We study two superluminal neutrino scenarios where [Formula: see text] is a constant. To be consistent with the OPERA, Borexino and ICARUS experiments and with the SN1987a observations, we assume that δvν on the Earth is about three-order larger than that on the interstellar scale. To explain the theoretical challenges from the Bremsstrahlung effects and pion decays, we consider the deformed Lorentz invariance, and show that the superluminal neutrino dispersion relations can be realized properly while the modifications to the dispersion relations of the other Standard Model particles can be negligible. In addition, we propose the deformed energy and momentum conservation laws for a generic physical process. In Scenario I the momentum conservation law is preserved while the energy conservation law is deformed. In Scenario II the energy conservation law is preserved while the momentum conservation law is deformed. We present the energy and momentum conservation laws in terms of neutrino momentum in Scenario I and in terms of neutrino energy in Scenario II. In such formats, the energy and momentum conservation laws are exactly the same as those in the traditional quantum field theory with Lorentz symmetry. Thus, all the above theoretical challenges can be automatically solved. We show explicitly that the Bremsstrahlung processes are forbidden and there is no problem for pion decays.

SUPERNOVAE, LANDAU LEVELS, AND PULSAR KICKS

We derive the energy asymmetry given the proto-neutron star during the time when the neutrino sphere is near the surface of the proto-neutron star, using the modified URCA process. The electrons produced with the anti-neutrinos are in Landau levels due to the strong magnetic field, and this leads to asymmetry in the neutrino momentum, and a pulsar kick. Our main prediction is that the large pulsar kicks start at about 10 s and last for about 10 s, with the corresponding neutrinos correlated in the direction of the magnetic field.

Form Factors and Absolute Branching Fractions for D0 → K(π)ℓν

We present a study of D0 decaying to K-ℓ+ν and π-ℓ+ν final states using a 282 fb-1 data sample collected by the Belle experiment at the KEKB e+e- collider. The D0 flavor and momentum are tagged through a full reconstruction of the recoiling charm meson and additional mesons from fragmentation. The reconstruction method provides very good resolution in neutrino momentum and in q2 = (pℓ + pν)2. Normalizing to the total number of D0 tags, we measure the absolute branching fractions to be [Formula: see text] and [Formula: see text] and the semi-leptonic form factors (within the modified pole model) [Formula: see text] and [Formula: see text].