A search is presented for a third-generation leptoquark (LQ) coupled exclusively to a tau lepton and a b quark. The search is based on proton-proton collision data at a center-of-mass energy of 13 TeV recorded with the CMS detector, corresponding to an integrated luminosity of 138 fb(-1). Events with tau leptons and a varying number of jets originating from b quarks are considered, targeting the single and pair production of LQs, as well as nonresonant t-channel LQ exchange. An excess is observed in the data with respect to the background expectation in the combined analysis of all search regions. For a benchmark LQ mass of 2 TeV and an LQ-b-tau coupling strength of 2.5, the excess reaches a local significance of up to 2.8 standard deviations. Upper limits at the 95% confidence level are placed on the LQ production cross section in the LQ mass range 0.5-2.3 TeV, and up to 3 TeV for t-channel LQ exchange. Leptoquarks are excluded below masses of 1.22-1.88 TeV for different LQ models and varying coupling strengths up to 2.5. The study of nonresonant tau tau production through t-channel LQ exchange allows lower limits on the LQ mass of up to 2.3 TeV to be obtained.

Null, N., Hayrapetyan, A., Tumasyan, A., Adam, W., Andrejkovic, J.W., Bergauer, T., et al. (2024). Search for a third-generation leptoquark coupled to a τ lepton and a b quark through single, pair, and nonresonant production in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2024(5) [10.1007/jhep05(2024)311].

Search for a third-generation leptoquark coupled to a τ lepton and a b quark through single, pair, and nonresonant production in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV

Ciocci, M. A.;Messineo, A.;
2024-01-01

Abstract

A search is presented for a third-generation leptoquark (LQ) coupled exclusively to a tau lepton and a b quark. The search is based on proton-proton collision data at a center-of-mass energy of 13 TeV recorded with the CMS detector, corresponding to an integrated luminosity of 138 fb(-1). Events with tau leptons and a varying number of jets originating from b quarks are considered, targeting the single and pair production of LQs, as well as nonresonant t-channel LQ exchange. An excess is observed in the data with respect to the background expectation in the combined analysis of all search regions. For a benchmark LQ mass of 2 TeV and an LQ-b-tau coupling strength of 2.5, the excess reaches a local significance of up to 2.8 standard deviations. Upper limits at the 95% confidence level are placed on the LQ production cross section in the LQ mass range 0.5-2.3 TeV, and up to 3 TeV for t-channel LQ exchange. Leptoquarks are excluded below masses of 1.22-1.88 TeV for different LQ models and varying coupling strengths up to 2.5. The study of nonresonant tau tau production through t-channel LQ exchange allows lower limits on the LQ mass of up to 2.3 TeV to be obtained.
2024
Null, N., Hayrapetyan, A., Tumasyan, A., Adam, W., Andrejkovic, J.W., Bergauer, T., et al. (2024). Search for a third-generation leptoquark coupled to a τ lepton and a b quark through single, pair, and nonresonant production in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2024(5) [10.1007/jhep05(2024)311].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1326997