The Glashow resonance in neutrino-photon scattering

Understand

Reactions ${\nu_l}\gamma\rightarrow W^+l^-\,(l=e,\mu,\tau)$ near the threshold $\sqrt{s}=m_W+m_l$ are analyzed.

• Two independent calculations of the corresponding cross sections (straightforward calculations using the Standard Electroweak Lagrangian and calculations in the framework of the parton model) are compared.
• It is shown that the Standard Electroweak Theory strongly suggests that these reactions proceed via the Glashow resonances.
• Accordingly, a hypothesis that the on-shell $W$ bosons in the reactions ${\nu_l}\gamma\rightarrow$$W^+l^-$ are the Glashow resonances is put forward.