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Related papers: CP and T Violation in KL -> pi^+pi^-e^+e^-

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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 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 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

We present new results on the related rare KL decay modes KL -> pi+ pi- gamma and KL -> pi+ pi- e+ e-. KTeV has performed the first direct measurement of the form factor for the "direct emission" component of KL -> pi+ pi- gamma decays, a…

High Energy Physics - Experiment · Physics 2007-05-23 John Belz

We study the CP-violating asymmetry {\cal A}_{\rm CP}, which arises, in \eta\to\pi^+\pi^- e^+e^-, from the angular correlation of the e^+ e^- and \pi^+\pi^- planes due to the interference between the magnetic and electric decay amplitudes.…

High Energy Physics - Phenomenology · Physics 2014-11-17 Dao-Neng Gao

The rare decay K_L -> pi pi e e that has recently been observed by KTeV is analyzed in chiral perturbation theory at the one-loop level.

High Energy Physics - Phenomenology · Physics 2007-05-23 Martin J. Savage

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

Data from the KTeV experiment have provided many opportunities for studies of fundamental symmetries in nature, not just CP. We present new limits on the lepton flavor violating decays K_L -> pi0 mu e, K_L -> pi0 pi0 mu e and pi0 -> mu e.…

High Energy Physics - Experiment · Physics 2019-08-14 Michael Akashi-Ronquest

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

The recent results on the CP violating parameters Re(e'/e) and \Delta\phi = \phi_{00}-\phi_{+-} reported by the KTeV Collaboration are analyzed with a view to constrain CP, T and CPT violations in a decay process. Combining with some…

High Energy Physics - Phenomenology · Physics 2009-10-31 Y. Takeuchi , S. Y. Tsai

The recent discovery of a large CP violating asymmetry in K(L) --> PI+ PI- E+ E- mode has prompted us to seach for the associated K(L) --> PI0 PI0 E+ E- decay mode in the KTeV-E799 experiment at Fermilab. In 2.7E+11 K(L) decays, one…

High Energy Physics - Experiment · Physics 2008-11-26 KTeV Collaboration , A. Alavi-Harati

We comment on CP, T and CPT violation in the light of interesting new data from the CPLEAR and KTeV Collaborations on neutral kaon decay asymmetries. Other recent data from the CPLEAR experiment, constraining possible violations of CPT and…

High Energy Physics - Phenomenology · Physics 2009-09-11 John Ellis , N. E. Mavromatos

We report on a search for the decay Kl -> pi0 e+ e- carried out by the KTeV/E799 experiment at Fermilab. This decay is expected to have a significant CP violating contribution and the measurement of its branching ratio could support the CKM…

High Energy Physics - Experiment · Physics 2008-11-26 A. Alavi-Harati

The recent Belle and Babar measurements of the branching ratios $B^- \to \pi^+ \pi^- K^-$ and $B^- \to K^+ K^- K^-$ and $B^\pm \to \chi_{c0} K^\pm$ have renewed interests in these decays as another mean to look for direct CP violation in B…

High Energy Physics - Phenomenology · Physics 2017-08-23 T. N. Pham

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 show that the CP-violating effect in K^0 vs \bar K^0-->\pi^+\pi^-\pi^0 decays differs from that in K_{\rm L}-->\pi^+\pi^-, K_{\rm L}-->\pi^0\pi^0 or the semileptonic K_{\rm L} transitions, if there exists CPT violation in K^0-\bar{K}^0…

High Energy Physics - Phenomenology · Physics 2009-10-31 Zhi-zhong Xing

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 report updated measurements of indirect and direct CP asymmetry in decays $D^0 \to K^+K^-,\pi^+\pi^-$ and a new measurement of direct and indirect CP asymmetry in decays $D^0 \to \pi^0\pi^0$, using the full data sample of the Belle…

High Energy Physics - Experiment · Physics 2019-08-13 Tara Nanut

The epsilon-impurity of the K_L wave-function gives rise to a huge CP-violating effect in the decay K_L -> pi^+ pi^- gamma which is hidden in the polarization state (Stokes vector) of the photon. One component of the Stokes vector is CP-odd…

High Energy Physics - Phenomenology · Physics 2009-10-31 L. M. Sehgal

We summarize the results of two papers in which we have studied CP violation in inclusive and exclusive decays b -> d e^+e^-. Two CP-violating effects are calculated: the partial rate asymmetry between b and \bar{b} decay, and the asymmetry…

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