LHC signatures of τ-flavoured vector leptoquarks

• Published in: The journal of high energy physics 2022-08, Vol.2022 (8), p.127-31, Article 127
• Main Authors: Bernigaud, Jordan, Blanke, Monika, de Medeiros Varzielas, Ivo, Talbert, Jim, Zurita, José
• Format: Article
• Language: English
• Subjects: Anomalies; Asymmetry; Classical and Quantum Gravitation; Couplings; Elementary Particles; Fermions; Flavor (particle physics); Flavour Symmetries; High energy physics; Large Hadron Collider; Leptons; New Light Particles; Phenomenology; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Quarks; Ratios; Regular Article - Theoretical Physics; Relativity Theory; Searching; Signatures; Specific BSM Phenomenology; Standard model (particle physics); String Theory; Symmetry; Theories of Flavour
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP08(2022)127

A bstract We consider the phenomenological signatures of Simplified Models of Flavourful Leptoquarks, whose Beyond-the-Standard Model (SM) couplings to fermion generations occur via textures that are well motivated from a broad class of ultraviolet flavour models (which we briefly review). We place particular emphasis on the study of the vector leptoquark ∆ μ with assignments ( 3 , 1 , 2 / 3) under the SM’s gauge symmetry, SU(3) C × SU(2) L × U(1) Y , which has the tantalising possibility of explaining both R K ∗ and R D ∗ anomalies. Upon performing global likelihood scans of the leptoquark’s coupling parameter space, focusing in particular on models with tree-level couplings to a single charged lepton species, we then provide confidence intervals and benchmark points preferred by low (er)-energy flavour data. Finally, we use these constraints to further evaluate the (promising) Large Hadron Collider (LHC) detection prospects of pairs of τ -flavoured ∆ μ , through their distinct (a)symmetric decay channels. Namely, we consider direct third-generation leptoquark and jets plus missing-energy searches at the LHC, which we find to be complementary. Depending on the simplified model under consideration, the direct searches constrain the ∆ μ mass up to 1500-1770 GeV when the branching fraction of ∆ μ is entirely to third-generation quarks (but are significantly reduced with decreased branching ratios to the third generation), whereas the missing-energy searches constrain the mass up to 1150-1700 GeV while being largely insensitive to the third-generation branching fraction.