Low-energy photon production in neutrino neutral-current interactions

摘要: The search for ${\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{e}$ oscillations by the MiniBooNE Collaboration at Fermilab has revealed a low-energy signal which could be due either to electrons produced ${\ensuremath{\nu}}_{e}$ or photons interaction of weak neutral current on target nucleus. One contribution latter is Wess-Zumino-Witten anomaly leading term in Lagrangian proportional ${\ensuremath{\epsilon}}^{\ensuremath{\mu}\ensuremath{\nu}\ensuremath{\kappa}\ensuremath{\lambda}}{Z}_{\ensuremath{\mu}}{\ensuremath{\omega}}_{\ensuremath{\nu}}{F}_{\ensuremath{\kappa}\ensuremath{\lambda}}$. This normalized with help known rates processes ${f}_{1}\ensuremath{\rightarrow}\ensuremath{\rho}\ensuremath{\gamma}$ and $\ensuremath{\tau}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\tau}}{a}_{1}$. A rate about $1/4$ that employed several previous estimates obtained. As had already been found play subdominant role photon production (e.g., comparison $\mathrm{\ensuremath{\Delta}}$ excitation decay), present estimate reduces its strength even further.