Phenomenology of TeV scale leptoquarks at the large hadron collider Current status and future prospects

Abstract

Despite its successful predictions, the Standard Model (SM) is not a complete theory. There are newlinetheoretical issues and experimental observations that it cannot explain. Over the years, experimental newlinemeasurements of several observables have shown deviations from their SM-predicted values. For newlineinstance, the latest measurement of the anomalous magnetic moment of the muon (g and#8722; 2)µ by newlineFermilab shows a deviation of 4.2and#963;. There is a discrepancy of 7and#963; between the SM value and the newlineexperimentally observed value of the W boson mass as reported by the CDF collaboration. The newlineSM shows lepton-flavour universality (LFU), i.e., the couplings of leptons to the gauge bosons are newlineflavour independent in the SM. However, the measurements of the leptonic decays of B-mesons at newlineBaBar, Belle, and LHCb indicate some LFU violations. These deviations are popularly referred to as newlineB-anomalies those seen in the RD(and#8727;) and RK(and#8727;) observables are some of the well-known examples. newlineUntil recently, the experimental values of RD and RDand#8727; exceeded their SM predictions by 1.4and#963; and newline2.5and#963;, respectively. On the other hand, the deviations in the RK and RKand#8727; measurements were smaller newlinethan the theoretical predictions by about 3.1and#963;. The current measurement of RD still stands 2and#963; newlineaway from the SM, putting the global average of RD(and#8727;) (combined) at 3.2and#963;. newlineThe deviations in the measurement of (g and#8722;2)µ, W boson mass anomaly and the B-anomalies led newlineto numerous beyond the Standard Model (BSM) explanations in the literature. Among these, the newlinemost popular ones involve a class of hypothetical particles known as the Leptoquarks (LQs). LQs are newlinescalar (sLQ) or vector (vLQ) bosons that are electromagnetically charged. They are colour triplets newlinewith nonzero lepton numbers. They can form various weak representations singlet, doublet or newlinetriplet. They appear in theories such as R-parity violating Supersymmetry, SU(5) Grand Unified newlineTheories, Pati-Salam models, Technicolour models, etc. The LHC has an active LQ-search program. newlineTheir connections to the lepton and colour sector make them idea