English
Related papers

Related papers: CP violation in Semi-Leptonic $\tau$ decays

200 papers

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 point out that dynamics known from the observed CP violation in $K_L\to \pi^{\mp}l^{\pm}\nu$ generate a CP asymmetry of $3.3\cdot 10^{-3}$ in $\tau^{\pm} \to \nu K_L\pi^{\pm}$. CPT invariance requires the same asymmetry in the more…

High Energy Physics - Phenomenology · Physics 2010-04-05 I. I. Bigi , A. I. Sanda

Assuming a minimal seesaw model with two heavy neutrinos (N), we examine effects of leptonic CP violation induced by approximate mu-tau symmetric interactions. As long as N is subject to the mu-tau symmetry, we can choose CP phases of Dirac…

High Energy Physics - Phenomenology · Physics 2008-11-26 Teppei Baba , Masaki Yasue

CP violation in the decays $t \to \ell^+\nu b$ and $\bar t \to \ell^-\bar\nu \bar b$ from the production process $e^-e^+ \to \ttbar$ is discussed. Since the asymmetry proposed as a measure of CP violation vanishes even at the one-loop level…

High Energy Physics - Phenomenology · Physics 2009-09-01 Bohdan Grzadkowski , Wai-Yee Keung

Motivated by the $2.8\sigma$ discrepancy observed between the BaBar measurement and the Standard Model prediction of the CP asymmetry in $\tau\to K_S\pi\nu_\tau$ decays, as well as the prospects of future measurements at Belle II, we…

High Energy Physics - Phenomenology · Physics 2019-12-25 Feng-Zhi Chen , Xin-Qiang Li , Ya-Dong Yang , Xin Zhang

CP violation in semileptonic top-quark decay is investigated by exactly using one charged- and three neutral-Higgs bosons obtained by solving the Higgs mass matrix in two-Higgs doublet model. The CP-violating up-down asymmetry of leptons…

High Energy Physics - Phenomenology · Physics 2009-10-31 Tsutom Hasuike , Toshihiko Hattori , Seiichi Wakaizumi

We consider CP violating effects in the decays $\tau\rightarrow (3\pi)\nu_\tau$ where both the ${\rm J}^{\rm P}=1^+$ resonance, $a_1$, and ${\rm J}^{\rm P}=0^-$ resonance, $\pi^\prime$, can contribute. The interference between the $a_1$ and…

High Energy Physics - Phenomenology · Physics 2009-09-25 S. Y. Choi , K. Hagiwara , M. Tanabashi

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

CP violation from physics beyond the Standard Model is investigated in $B_{l4}$ decays: $B\to D\pi l\bar{\nu}_l$. The semileptonic $B$-meson decay to a $D$-meson with an emission of single pion is analyzed with heavy quark effective theory…

High Energy Physics - Phenomenology · Physics 2009-10-31 C. S. Kim , Jake Lee , W. Namgung

Using a sample of 12.2 million $\tau$-lepton pairs produced by $e^+e^-$ annihilation at $\sqrt{s}\sim 10.6 $GeV and collected by the CLEO detector, we search for and set limits on CP violation in $\tau$-lepton decays. For each event, we…

High Energy Physics - Phenomenology · Physics 2016-11-23 Thomas Coan

Direct CP violations in $B_{l4}$ decays ($B^\pm \to \pi^+\pi^- l^\pm {\nu}_l$) are investigated within the Standard Model (SM) and also in its extensions. In the decay processes, we include various excited states as intermediate states…

High Energy Physics - Phenomenology · Physics 2016-08-25 C. S. Kim , Jake Lee , W. Namgung

We show that direct CP violation in semi-leptonic and leptonic decays can occur in multi-Higgs doublet extensions of the electroweak standard model with flavor changing neutral currents. For pion and lepton decays these $CP$ violating…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. Pleitez

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

In this talk I review theoretical predictions for CP violation in non-leptonic hyperon decays in the Standard Model and models beyond. In the Standard Model the CP violating observable $A$ in the polarization asymmetries of $\Lambda \to p…

High Energy Physics - Phenomenology · Physics 2007-05-23 Xiao-Gang He

We study the uncertainties of the Standard Model (SM) predictions for CP violating B decays and investigate where and how supersymmetric (SUSY) contributions may be disentangled. The first task is accomplished by letting the relevant matrix…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Ciuchini , E. Franco , G. Martinelli , A. Masiero , L. Silvestrini

We study CP violation in the two-body decay of a scalar tau into a neutralino and a tau, which should be probed at the LHC and ILC. From the normal tau polarization, a CP asymmetry is defined which is sensitive to the CP phases of the…

High Energy Physics - Phenomenology · Physics 2011-09-21 Herbi Dreiner , Olaf Kittel , Suchita Kulkarni , Anja Marold

We consider the three--body decay stop_1 -> b tau+ tau-sneutrino and propose the asymmetry of the tau polarization perpendicular to the decay plane as a CP sensitive observable. We calculate this asymmetry in the Minimal Supersymmetric…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Bartl , T. Kernreiter , W. Porod

Supersymmetric (SUSY) theories include many new parameters, some of which are CP-violating. Assuming that SUSY is found at a future high-energy collider, we examine the decay stop2 -> stop1 tau- tau+ with an eye to obtaining information…

High Energy Physics - Phenomenology · Physics 2009-11-11 Ken Kiers , Alejandro Szynkman , David London

We study CP-violating effects in $B\to \psi K_{s}$ decay within minimal supersymmetric models with spontaneous CP-violation. We find that the CP-asymmetry predicted by the Standard Model in this decay, $\sin 2\beta \geq 0.4$, cannot be…

High Energy Physics - Phenomenology · Physics 2016-12-28 Oleg Lebedev

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