Nonresonant leptoquark with multigeneration couplings for $\mu \mu jj$ and $\mu \nu jj$ at the LHC

Alvarez, Ezequiel (International Center for Advanced Studies (ICAS), UNSAM, Campus Miguelete, 25 de Mayo y Francia, 1650 Buenos Aires, Argentina) ; Szewc, Manuel (International Center for Advanced Studies (ICAS), UNSAM, Campus Miguelete, 25 de Mayo y Francia, 1650 Buenos Aires, Argentina)

10 May 2019

Abstract: CMS has recently reported [A. M. Sirunyan et al. (CMS Collaboration), Search for pair production of second-generation leptoquarks at $\sqrt{s}=13\text{}\text{}\mathrm{TeV}$, Phys. Rev. D 99, 032014 (2019).] a moderate excess in the $\mu \nu jj$ final state in a second-generation leptoquark search, but they have disregarded it because the excess is not present in the $\mu \mu jj$ final state and because they do not observe the expected resonant peak in the distributions. As a proof of concept, we show that a simple leptoquark model including second- and third-generation couplings with non-negligible single- and nonresonant production in addition to usual pair production could explain the data—excess ($\mu \nu jj$), lack of excess ($\mu \mu jj$), and missing peak in the distributions—while being in agreement with collider constraints. We take this result and analysis as a starting point of a reconsideration of the ATLAS and CMS second-generation leptoquark searches. We also discuss which consequences and modifications should be performed in the searches to test if this deviation would correspond to a new physics signal. We observe that low-energy flavor constraints can be avoided by adding heavier particles to the model.

Published in: Physical Review D 99 (2019)