Same-sign dilepton puzzle

Abstract

Same-sign dileptons produced in neutrino interactions are not explained by charm production in lowest-order quantum chromodynamics. We investigate whether $\nu \overline{c}\to \mu \overline{b}$ production with $\overline{b}\to \overline{c}\to \overline{s}l\overline{\nu }$ cascade decay could account for the observed rates within the known constraints of weak universality, $\overline{c}$ content of the nucleon, and trimuon results. Even with full-strength ${\mathrm{}(c,b)\mathrm{}}_R$ coupling and maximal $\overline{c}$ normalization, the $\overline{b}$ mechanism is unable to explain the reported rate.