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

200 papers

We present precise measurements of CP and CPT symmetry based on the full dataset of K to 2pi decays collected by the KTeV experiment at FNAL. We measure the direct CP violation parameter Re(epsilon'/epsilon) = (19.2 pm 2.1)x10-4. We also…

High Energy Physics - Experiment · Physics 2009-09-15 E. T. Worcester

Four topics in theory of CP violation are reviewed. (a) CP violation in $B$ decays: We describe a new clean way of constraining the angle $\gamma$ of the unitarity triangle and how new CP violation in decay amplitudes can signal new…

High Energy Physics - Phenomenology · Physics 2009-09-25 Yosef Nir

We present a measurement of CP-violation parameters in the b->sq q penguin transitions (q=s,u,d) based on a 78/fb data sample collected at the Y(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral…

High Energy Physics - Experiment · Physics 2010-04-06 K. Abe

We study both CP conserving and violating contributions to the decay $K_L\to\pi^+\pi^-\nu\bar{\nu}$. We find that the decay branching ratio is dominated by the CP conserving part. In the standard CKM model, we estimate that for $m_t\sim…

High Energy Physics - Phenomenology · Physics 2010-11-01 C. Q. Geng , I. J. Hsu , Y. C. Lin

The sum of the CP-violating asymmetries A_Omega and A_Lambda in the decay sequence Omega->Lambda K, Lambda->p pi is presently being measured by the E871 experiment. We evaluate contributions to A_Omega from the standard model and from…

High Energy Physics - Phenomenology · Physics 2009-11-10 Jusak Tandean

A variety of CP violating asymmetries in $B^0$ decays is predicted in the Standard Model in terms of CKM (Cabibbo-Kobayashi-Maskawa) complex phases. These phases can also be determined from rate measurements of certain $B^+$ and $B^-$…

High Energy Physics - Phenomenology · Physics 2009-10-28 Michael Gronau

The LHCb Collaboration has recently found a large CP-violating rate asymmetry in the $b$-baryon decay $\Lambda^0_b \to pK^-\pi^+\pi^-$. This is the first observation of CP violation in baryon processes, opening a new window to test its…

High Energy Physics - Phenomenology · Physics 2025-04-09 Xiao-Gang He , Chia-Wei Liu , Jusak Tandean

In the presence of an electric dipole coupling of the top quark to a photon, and an analogous "weak" dipole coupling to the Z, CP violation in the process e+e- -> t tbar leads to the polarization of the top and anti-top. This polarization…

High Energy Physics - Phenomenology · Physics 2007-05-23 Saurabh D. Rindani

Due to the large mass of top quark, CP violation in the top-quark decay is sensitive to the interactions mediated by Higgs bosons. We consider CP violation in $t\rightarrow W^+ b$ decay by calculating consistently in unitary gauge the…

High Energy Physics - Phenomenology · Physics 2009-09-25 Tsutom Hasuike , Toshihiko Hattori , Toshio Hayashi , Seiichi Wakaizumi

We consider CP violating effects in decays of the type $B^\pm\to \gamma a^\pm_{1,2}$ where $a_{1,2}$ are the $J^P=1^+$ and $2^+$ resonances each decaying to the common final state via $a^\pm_{1,2} \to\pi^\pm\rho^0$. The resonances enhance…

High Energy Physics - Phenomenology · Physics 2010-11-01 D. Atwood , A. Soni

CP violation in the K system is pedagogically reviewed. We discuss its manifestations in the neutral K meson systems, in rare K meson decays and in decays of charged K mesons. Results from classical experiments, and perspectives for…

High Energy Physics - Experiment · Physics 2015-06-25 Juliet Lee-Franzini , Paolo Franzini

We study the CP-violating asymmetry in nonleptonic decay $\Lambda\to p\pi$. By employing the Skyrme model to calculate this decay amplitude contributed by the gluonic diploe operator, we find a possible large CP-violating asymmetry could be…

High Energy Physics - Phenomenology · Physics 2015-06-25 Ji-Hao Jiang , Mu-Lin Yan

We have searched for CP violation in the charmed meson decays $D^{+}_{(s)}\to K^0_S\pi^+$ and $D^{+}_{(s)}\to K^0_S K^+$ using 673 fb$^{-1}$ of data collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. No…

High Energy Physics - Experiment · Physics 2019-08-13 B. R. Ko , E. Won

We report measurements of the branching fractions and CP asymmetries for B^+- -> eta h^+- (h = K or pi) and the observation of the decay B^0 -> eta K^0 from the final data sample of 772x10^6 BBbar pairs collected with the Belle detector at…

High Energy Physics - Experiment · Physics 2019-08-13 C. -T. Hoi , P. Chang

We report the first observation of CP-violating asymmetries in B0 --> pi+pi- decays based on a 140 fb-1 data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We reconstruct…

High Energy Physics - Experiment · Physics 2019-08-14 K. Abe

We present a measurement of the direct CP violating asymmetry in the decay B0 -> K+pi- using 227 x 10^6 Y(4S) -> BBbar decays collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we observe a total signal…

High Energy Physics - Experiment · Physics 2008-11-26 BaBar Collaboration , B. Aubert

We observe 441 K_{L} -> e^{+} e^{-} e^{+} e^{-} candidate events with a background of 4.2 events and measure B(K_{L} -> e^{+} e^{-} e^{+} e^{-}) = (3.72 \pm 0.18(stat) \pm 0.23(syst)) \times 10^{-8} in the KTeV/E799II experiment at…

High Energy Physics - Experiment · Physics 2010-05-28 The KTeV Collaboration , A. Alavi-Harati

We review $CP$-violating observables in flavor tagged and untagged $D^0 \rightarrow K^{-}\pi^{+}$ decays and evaluate the $CP$ asymmetry difference between the two decays. We note that this commonly neglected difference is not zero in…

High Energy Physics - Experiment · Physics 2015-08-21 E. Won , B. R. Ko , B. Golob

We present a preliminary measurement of the time-dependent CP-violating asymmetry parameters S_pipi and C_pipi in neutral B decays to the pi^+/-pi^-/+ CP eigenstate, and an updated preliminary measurement of the charge asymmetry A_Kpi in B…

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

We report on the first observation of the decay KL -> pi0 ee gamma by the KTeV E799 experiment at Fermilab. Based upon a sample of 48 events with an estimated background of 3.6 +/- 1.1 events, we measure the KL -> pi0 ee gamma branching…

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