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Related papers: Large Effects of CP- and T-Violation in K^0 Decay

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The origin of the large CP-odd and T-odd asymmetry observed in the decay K_L -> pi^+ pi^- e^+ e^- is traced to the polarization properties of the photon in the decay K_L -> pi^+ pi^- gamma. The Stokes vector of the photon S = (S_1, S_2,…

High Energy Physics - Phenomenology · Physics 2009-10-31 L. M. Sehgal , J. van Leusen

I review the theoretical basis of the prediction that the decay K_L -> pi+ pi- e+ e- should show a large CP- and T-violation, a prediction now confirmed by the KTeV experiment. The genesis of the effect lies in a large violation of CP- and…

High Energy Physics - Phenomenology · Physics 2007-05-23 L. M. Sehgal

We report the first observation of a manifestly CP violating effect in the K(L)->pi+pi-e+e- decay mode. A large asymmetry was observed in the distribution of these decays in the CP-odd and T-odd angle phi between the decay planes of the…

High Energy Physics - Experiment · Physics 2012-08-27 KTeV Collaboration

The decay K_L -> pi0 e+ e- is being searched for as a signal of direct Delta S = 1 CP violation. We provide a thorough updating of the analysis of the three components of the decay: 1) Direct CP violation, 2) CP violation through the mass…

High Energy Physics - Phenomenology · Physics 2010-11-01 John F. Donoghue , Fabrizio Gabbiani

We consider the decay K^0 (K^0 bar) -> pi^+ pi^- e^+ e^- of a neutral K meson prepared in a state of strangeness +1 (-1). The time evolution of the state produces remarkable time-dependent effects in the angular distribution of the pi^+…

High Energy Physics - Phenomenology · Physics 2016-09-06 L. M. Sehgal , J. van Leusen

We study the CP violating effects in the decay of $\eta\to\pi^+\pi^-\gamma$. We show that to have CP violation in the decay, one has to consider both linear and circular photon polarizations. In the standard model, the polarizations are…

High Energy Physics - Phenomenology · Physics 2009-11-07 C. Q. Geng , J. N. Ng , T. H. Wu

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

We present a new analysis of the rare decay K_L -> pi0 e+ e- taking into account important experimental progress that has recently been achieved in measuring K_L -> pi0 gamma gamma and K_S -> pi0 e+ e-. This includes a brief review of the…

High Energy Physics - Phenomenology · Physics 2009-10-09 Gerhard Buchalla , Giancarlo D'Ambrosio , Gino Isidori

The time-dependent CP asymmetry in exclusive B^0(t) -> K^{*0}\gamma decays has been proposed as a probe of new physics in B decays. Recently, this method was extended to radiative decays into multibody hadronic final states such as B^0(t)->…

High Energy Physics - Phenomenology · Physics 2014-11-18 Benjamin Grinstein , Dan Pirjol

We examine the possibility of extracting CP-violating terms in the decay K0 -> Pi0 e+ e- by studying the time evolution of a K0 beam. We focus on the interference region and search for clear effects. We find that experiments which average…

High Energy Physics - Phenomenology · Physics 2010-11-01 Gerhard O. Koehler , Emmanuel A. Paschos

We investigate possible CP violating effects in $e^+e^-$ annihilation into top quark pairs. One of the interesting observable effects is the difference in production rates between the two CP conjugate polarized states $t_L\bar t_L$ and…

High Energy Physics - Phenomenology · Physics 2009-09-01 Darwin Chang , Wai-Yee Keung , Ivan Phillips

We consider a model for the decay Bbar^0 -> rho^0 gamma in which the short-distance amplitude determined by the Hamiltonian describing b -> d gamma is combined with a typical long-distance contribution Bbar^0 -> D^+ D^- -> rho^0 gamma. The…

High Energy Physics - Phenomenology · Physics 2009-11-10 L. M. Sehgal , J. van Leusen

I will here make some brief comments on the T- and CP- odd asymmetry observed by KTeV in the KL -> pi^+pi^-e^+e^- decay.

High Energy Physics - Experiment · Physics 2007-05-23 B. Winstein

We present a reanalysis of direct CP violation in the decay K_L -> pi^+ pi^- gamma. We point out an existing discrepancy between the theoretical and experimental definitions of epsilon'_{+-gamma}. Adopting the experimental definition of…

High Energy Physics - Phenomenology · Physics 2009-10-31 Jusak Tandean , G. Valencia

The amplitudes of $K \rightarrow \pi \gamma^* \rightarrow \pi e^+e^-$ and $K \rightarrow \pi \pi \gamma$ decays have been calculated within chiral Lagrangian approach including higher-order derivative terms and meson loops. The…

High Energy Physics - Phenomenology · Physics 2008-02-03 A. A. Bel'kov , A. V. Lanyov , A. Schaale

We study the decay rate and the CP violating asymmetry of the exclusive B-> pi ell+ ell- and B-> rho ell+ ell- decays in the case where one of the final leptons is polarized. We calculate the contributions coming from the individual…

High Energy Physics - Phenomenology · Physics 2011-09-13 Guray Erkol , Gursevil Turan , Jan Willem Wagenaar

Establishing CP violation in B0 (bar{B0}) --> l+ l- decays requires a measurement of polarization of the final lepton pair, or a precise determination of the B0 --> l+ l- and bar{B0} --> l+ l- rates. We first argue that if the amplitudes of…

High Energy Physics - Phenomenology · Physics 2014-11-18 Piotr H. Chankowski , Jan Kalinowski , Zbigniew Was , Malgorzata Worek

The dependence of K_{S,L}->\pi^{+}\pi^{-}\gamma decay probabilities on photon polarization is calculated. The phases of terms of amplitude that arise from the pion-pion interaction are obtained by using a simple realistic model of pion-pion…

High Energy Physics - Phenomenology · Physics 2015-06-25 S. S. Bulanov

Motivated by the possible discrepancy between the observed CP asymmetry and that of standard model expectation in the decay mode B^0 -> phi K_S, we study the corresponding vector vector decay mode B^0 -> phi K^*. In order to obtain decisive…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. K. Giri , R. Mohanta

We report on a search for CP violation in the decay $ D^\pm \to K^0_{\scriptscriptstyle S} \pi^\pm $ using a data set corresponding to an integrated luminosity of $ 469\,\,fb^{-1} $ collected with the \slshape B\kern-0.1em{\smaller…

High Energy Physics - Experiment · Physics 2011-06-07 The BABAR Collaboration , P. del Amo Sanchez
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