Constraints on scalar and vector leptoquarks from the LHC Higgs data

Abstract

We study contributions of single scalar or vector leptoquark (LQ) to loop-induced Higgs processes, gluon fusion production ($gg\to h$) and $h\to {\hat{I}}^3{\hat{I}}^3$ decay, by analyzing the current Higgs data from the LHC Run I and II. Scalar LQ is studied in a model independent way, while the vector LQ $U_1(3,1,2/3)$ is discussed in the '4321' model. Constraints on the interactions of LQ and Higgs boson are obtained. We provide a method to determine vacuum expectation values ${\upsilon }_3$ and ${\upsilon }_1$ of the new scalar fields $\hat{I}{\text{c◯}}_3$ and $\hat{I}{\text{c◯}}_1$ in the '4321' model via the combination of Higgs data and measurements of $R_{D^{(\ast )}}$ and $R_{K^{(\ast )}}$.