Scalar leptoquark pair production at the LHC: precision predictions in the era of flavour anomalies

Journal of High Energy Physics

Christoph Borschensky¹  Daniel Schwartländer²  Anna Kulesza²  Benjamin Fuks³ 

[1] Institute for Theoretical Physics, University of Tübingen;Institute for Theoretical Physics, WWU Münster;Laboratoire de Physique Théorique et Hautes Energies (LPTHE), UMR 7589, Sorbonne Université et CNRS;

关键词: Perturbative QCD;    Beyond Standard Model;    Resummation;   

DOI  :  10.1007/JHEP02(2022)157

来源: DOAJ

【 摘 要 】

Abstract We comprehensively examine precision predictions for scalar leptoquark pair production at the LHC. In particular, we investigate the impact of lepton t-channel exchange diagrams that are potentially relevant in the context of leptoquark scenarios providing an explanation for the flavour anomalies. We also evaluate the corresponding total rates at the next-to-leading order in QCD. Moreover, we complement this calculation with the resummation of soft-gluon radiation at the next-to-next-to-leading logarithmic accuracy, hence providing the most precise predictions for leptoquark pair production at the LHC to date. Relying on a variety of benchmark scenarios favoured by the anomalies, our results exhibit an interesting interplay between the t-channel diagram contributions, the flavour texture satisfied by the leptoquark Yukawa couplings, the leptoquark masses and their representations under the Standard Model gauge group, as well as the chosen set of parton densities used for the numerical evaluations. The net effect on a cross section turns out to be very non-generic and ranges up to about 60% with respect to the usual next-to-leading-order predictions in QCD (i.e. without any t-channel contribution) for some scenarios considered. Dedicated calculations are thus required for any individual leptoquark model that could be considered in a collider analysis in order to assess the size of the studied corrections. In order to facilitate such calculations we provide dedicated public numerical packages.

【 授权许可】

Unknown