arXiv subjects

J. N. Ng

Publications and source records attributed to J. N. Ng.

21 records · Page 2Linked to original sources

arXiv1999

Singlet Interacting Neutrinos in the Extended Zee Model and Solar Neutrino Transformation

We study the impact of Standard Model singlet neutrinos on neutrino flavor transformation. We focus on an extension of the Zee model which includes singlet neutrinos, and find that the best limits on the interactions of the singlet neutrinos come from astrophysical phenomena. Singlet neutrino-electron scattering will impact both the mattter enhanced flavor transformation potential as well as detector cross sections. If electron neutrino - singlet neutrino oscillations are responsible for the solar neutrino anomaly, then the limit on the singlet neutrino interaction strength is of order of the weak interaction scale. Zee model modification of nu_tau - e scattering also impacts solar neutrino transformation, although this interaction is more tightly constrained.

hep-ph↗

arXiv1999

Rare Pionium Decays and Pion Polarizability

We calculate the decay of pionium atoms into two photons. The pion polarizability gives rise to a 10% correction to the corresponding decay width for pointlike pions. This opens the possibility to obtain the difference between the electric and magnetic polarizability of the charged pion from a future measurement of the branching fraction of pionium into two photons. For such an experiment the ππ-scattering lengths would have to be known to better than 5% precision. We also comment on the contribution of the axial anomaly to the decay of pionium into γπ^0.

hep-ph↗

arXiv1999

A Study of the Charged Scalar in the Zee Model

An extension of the Zee model involving a light right handed neutrino, nu_R is considered. We update constraints on couplings between the bilepton scalar, the active neutrinos, nu_R and the charged leptons. We find that the most stringent constraint currently comes from measurements limiting the width of the decay mu -> e gamma. These are used to predict the upper bound on violation of lepton universality in leptonic W boson decays and rare Z decays, such as Z -> e mu.

hep-ph↗