A measurement of the high-mass τ τ ¯ production cross-section at s = 13 TeV with the ATLAS detector and constraints on new particles and couplings

UNSPECIFIED (2025) A measurement of the high-mass τ τ ¯ production cross-section at s = 13 TeV with the ATLAS detector and constraints on new particles and couplings. Journal of High Energy Physics, 2025 (10): 054. ISSN 1029-8479

Abstract

The production cross-section of high-mass τ-lepton pairs is measured as a function of the dilepton visible invariant mass, using 140 fb−1 of s=13 TeV proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider. The measurement agrees with the predictions of the Standard Model. A fit to the invariant mass distribution is performed as a function of b-jet multiplicity, to constrain the non-resonant production of new particles described by an effective field theory or in models containing leptoquarks or Z′ bosons that couple preferentially to third-generation fermions. The constraints on new particles improve on previous results, and the constraints on effective operators include those affecting the anomalous magnetic moment of the τ-lepton.