  We consider massive photon decay reactions via intermediate states of
electron-electron-holes and proton-proton-holes into neutrino-antineutrino
pairs in the course of neutron star cooling. These reactions may become
operative in hot neutron stars in the region of proton pairing where the photon
due to the Higgs-Meissner effect acquires an effective mass $m_{\gamma}$ that
is small compared to the corresponding plasma frequency. The contribution of
these reactions to neutrino emissivity is calculated; it varies with the
temperature and the photon mass as $T^{3/2}m_{\gamma}^{7/2} e^{-m_{\gamma}/T}$
for $T < m_{\gamma}$. Estimates show that these processes appear as extra
efficient cooling channels of neutron stars at temperatures $T \simeq
(10^9-10^{10})$ K.
