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Related papers: A "Known" CP Asymmetry in $\tau$ Decays

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Direct CP asymmetry in semi-leptonic $\tau$ decays is an intriguing hint for new physics beyond the standard model. We investigate the CP asymmetry in $\tau^- \to K_S^0 \pi^- \nu_\tau$ and $\tau^- \to K^- \pi^0 \nu_\tau$ decays in…

High Energy Physics - Phenomenology · Physics 2023-05-31 Gaber Faisel , S. Khalil

It had been suggested to probe CP violation in {\tau} \rightarrow {\nu}K{\pi} decays with K0 -K ^{-}0 oscillation to produce ACP({\tau}- \rightarrow {\nu}KS{\pi}-) = (0.36\pm0.01)%. BaBar has found ACP({\tau}- \rightarrow {\nu}KS{\pi}-[\geq…

High Energy Physics - Phenomenology · Physics 2012-06-21 I. I. Bigi

The SM predicts zero value for {\bf CP} \& {\bf T} violation in the decays of $\tau$ leptons -- except $\tau^- \to \nu K_S [\pi^-/\pi^-\pi^0 ...]$. Our community could establish impact of New Dynamics (ND) in a {\bf CP} asymmetry in a…

High Energy Physics - Phenomenology · Physics 2022-01-07 I. I. Bigi

The leading order contribution to the direct CP asymmetry in tau^{+/-} -> K^{+/-} pi^0 nu_{tau} decay rates is evaluated within the Standard Model. The weak phase required for CP violation is introduced through an interesting mechanism…

High Energy Physics - Phenomenology · Physics 2009-11-11 D. Delepine , G. Lopez Castro , L. T. Lopez Lozano

We present here the CP asymmetries in the decay rate and angular distributions of $\tau\to K_S\pi\nu_\tau$ decays in the Standard Model (SM) and beyond (BSM). The CP asymmetries in the SM are induced by the CP violation in $K^0-\bar{K}^0$…

High Energy Physics - Phenomenology · Physics 2024-07-08 Feng-Zhi Chen , Xin-Qiang Li

We discuss the ways to find CP violation in the decay of $\tau^\pm\to \nu_\tau + 3\pi$ from unpolarized as well as polarized $\tau^\pm$.

High Energy Physics - Phenomenology · Physics 2007-05-23 Yung Su Tsai

In this work, we study the $CP$ asymmetry in the angular distribution of $\tau\to K_S\pi\nu_\tau$ decays, taking into account the known $CP$ violation in $K^0-\bar{K}^0$ mixing. It is pointed out for the first time that, once the…

High Energy Physics - Phenomenology · Physics 2020-06-24 Feng-Zhi Chen , Xin-Qiang Li , Ya-Dong Yang

We study CP violation in semi-leptonic $\tau$ decays and we determine the conditions necessary to be able to define a observable CP asymmetry. We apply these conditions in both models, the standard model for the electroweak interactions and…

High Energy Physics - Phenomenology · Physics 2008-11-26 David Delepine

We consider CP-violating effects in tau -> 3 pi nu_ tau and 4 pi nu_ tau (Delta S = 0), and tau -> K pi pi nu_tau (Delta S = 1), assuming that the usual Standard Model amplitudes for these processes interfere with analogous amplitudes…

High Energy Physics - Phenomenology · Physics 2013-01-01 Ken Kiers

An intriguing opposite sign of the CP violating asymmetry was recently measured in the tau decay modes tau -> Ks pi nutau by the BaBar collaboration, than that expected within the Standard Model. If this result is confirmed with higher…

High Energy Physics - Phenomenology · Physics 2014-07-23 H. Zeen Devi , L. Dhargyal , Nita Sinha

We examine CP violation in the Delta S=0 decays tau -> omega pi nu_tau and tau -> a_1 pi nu_tau and the Delta S=1 decay tau -> K pi pi nu_tau. We assume that the new physics is a charged Higgs. We show that sizeable CP-violating effects are…

High Energy Physics - Phenomenology · Physics 2008-08-26 Ken Kiers

We study the direct CP violation in the $\tau^\pm\rightarrow K^\pm \rho^0 (\omega)\nu_\tau \rightarrow K^\pm \pi^+\pi^-\nu_\tau$ decay process in the Standard Model. An interesting mechanism involving the charge symmetry violating mixing…

High Energy Physics - Phenomenology · Physics 2015-06-02 Chao Wang , Xin-Heng Guo , Ying Liu , Rui-Cheng Li

The last three years have seen a phase transition in our knowledge about CP violation: (i) Direct CP violation has been established in $K_L \to \pi \pi$. (ii) The first CP violation outside $K_L$ decays has been observed in $B_d \to \psi…

High Energy Physics - Phenomenology · Physics 2017-08-23 I. I. Bigi

BaBar has found $A_{\rm CP}(\tau^- \to \nu K_S\pi^- [\geq \pi^0]) = (-0.36 \pm 0.23 \pm 0.11)%$ with 2.8 $\sigma$ difference with SM prediction $A_{\rm CP}(\tau^- \to \nu K_S\pi^-) = (0.36 \pm 0.01)%$ based on $K^0 - \bar K^0$ oscillation.…

High Energy Physics - Phenomenology · Physics 2012-10-11 I. I. Bigi

We report a search for CP violation in the decay \tau- -> \pi - \K^0_S (>= 0 \pi 0) \nu_\tau\ using a dataset of 437 million \tau\ lepton pairs, corresponding to an integrated luminosity of 476 fb^{-1}, collected with the BABAR detector at…

High Energy Physics - Experiment · Physics 2013-05-30 The BABAR Collaboration

We apply the effective field theory formalism that was used to study CP violation induced by heavy new physics in the $\tau\to K_S \pi\nu_\tau$ decays to the other two-meson tau decay channels. We focus on the rate and the forward-backward…

High Energy Physics - Phenomenology · Physics 2025-02-04 Daniel A. López Aguilar , Javier Rendón , Pablo Roig

We discuss the test of CP and CPT violation in $\tau$ decay without using the polarized electron beam by comparing partial fractions of $\tau^-$ and $\tau^+$ decay into channels with strong final state interactions. For example,…

High Energy Physics - Phenomenology · Physics 2015-06-25 Yung Su Tsai

We proceed to study the $CP$ asymmetry in the angular distributions of $\tau\to K_S\pi\nu_\tau$ decays within a general effective field theory framework including four-fermion operators up to dimension-six. It is found that, besides the…

High Energy Physics - Phenomenology · Physics 2022-02-09 Feng-Zhi Chen , Xin-Qiang Li , Shi-Can Peng , Ya-Dong Yang , Hong-Hao Zhang

We update the theoretical analysis of the CP-violating asymmetry in the decay K_L -> pi+ pi- e+ e-, relying on chiral perturbation theory and on the most recent phenomenological information. With the experimentally determined magnetic…

High Energy Physics - Phenomenology · Physics 2014-11-17 G. Ecker , H. Pichl

The likelihood of a sizable, direct CP-violating asymmetry in the decays $B^\mp\to K^\mp\eta$, is calculated within the framework of the model which originally predicted a sizeable asymmetry in $\pi^\mp\eta(\eta')$. It is shown in a…

High Energy Physics - Phenomenology · Physics 2015-06-25 Saul Barshay , Georg Kreyerhoff
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