Nonresonant leptoquark with multigeneration couplings for μμjj and μνjj at the LHC

摘要

CMS has recently reported [A.?M. Sirunyan et al. (CMS Collaboration), Search for pair production of second-generation leptoquarks at s = 13 ? ? TeV , Phys. Rev. D 99 , 032014 (2019).] a moderate excess in the μ ν j j final state in a second-generation leptoquark search, but they have disregarded it because the excess is not present in the μ μ j j 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 ( μ ν j j ), lack of excess ( μ μ j j ), 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.