The Leptoquark Implication from the CMS and IceCube Experiments

Abstract

The recent excess in the CMS measurements of $eejj$ and $eνjj$ channels and the emergence of PeV comsic neutrino events at the IceCube experiment share an intriguing implication for a leptoquark with a 600-650 GeV mass. We investigate the CMS constraints on the flavor structure of a scenario with the minimal leptoquark Yukawa couplings and correlate such a scenario to the resonant enhancement in the very high energy shower event rates at the IceCube. We find for a single leptoquark, the CMS signals require large couplings to the third generation leptons. This leads to an enhancement in the $ν_τ$-nucleon scattering cross-section and subsequently more $ν_τ$ events at PeV energies. However, a visible enhancement above the Standard Model scattering would require a leptoquark Yukawa coupling larger than one that can be easily tested at the upcoming LHC runs.

PRD version. Meson decay constraints and additional citations are added. 6 pages, 2 figures, 1 table