Abstract:
We examine the rare decays τ− → π−η(′)ντ that are G-parity suppressed within
the Standard Model and provide valuable insights into new physics through interactions
beyond the SM. In this study, we used an effective field theory framework
to investigate the sensitivity of various observables associated with these decays,
incorporating interactions within the Standard Model fields up to six-dimensional
operators, under the assumption of massless and left-handed neutrinos. Our findings
indicate that the examined observables can effectively explain the underlying
dynamics of these decays, showing significant sensitivity to scalar and tensor
couplings. Upcoming experiments such as Belle II, LHCb upgrades, and future
electron-positron colliders aim to investigate τ decays with high accuracy, potentially
uncovering new physics beyond the Standard Model.
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