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Related papers: First Observation and Study of the $K^\pm \to \pi^…

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A precision measurement of the ratio RK of the rates of kaon leptonic decays K+- --> e nu and K+- --> mu nu with the full data sample collected by the NA62 experiment at CERN in 2007-2008 is reported. The result, obtained by analysing…

High Energy Physics - Experiment · Physics 2013-01-30 The NA62 collaboration

From 56 days of data taking in 2002, the NA48/1 experiment observed 6316 Xi0 --> Sigma+ e- nubar candidates (with the subsequent Sigma+ --> p pi0 decay) and 555 anti-Xi0 --> anti-Sigma+ e+ nu candidates with background contamination of…

High Energy Physics - Experiment · Physics 2008-11-26 I Collaboration

Using a 281 pb^{-1} data sample collected at the psi(3770) with the CLEO-c detector, we present the first absolute branching fraction measurement of the decay D^0 rightarrow K^-pi^+pi^-e^+nu_e at a statistical significance of about 4.0…

High Energy Physics - Experiment · Physics 2010-04-08 M. Artuso , CLEO Collaboration

Recent measurements of kaon decays provide new information about CKM unitarity, lepton universality, and discrete symmetries. KLOE-2, the proposed extension of the kaon physics program at Frascati, will extend the world data set on kaon…

High Energy Physics - Experiment · Physics 2009-03-03 Matthew Moulson

The KOTO experiment was designed to observe and study the K$^{0}_{L} \rightarrow$ $\pi^{0}\nu\bar{\nu}$ decay at J-PARC. The Standard Model (SM) prediction for the process is (3.0 $\pm$ 0.3) x 10$^{-11}$ with small uncertainties. This…

High Energy Physics - Experiment · Physics 2019-10-17 Brian Beckford

Using the complete KTeV data set of 5241 candidate KL->pi+pi-e+e- decays (including an estimated background of 204+-14 events), we have measured the coupling gCR=0.163+- 0.014(stat)+-0.023(syst) of the CP conserving charge radius process…

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

In the first year of physics run, the E949 experiment at Brookhaven National Laboratory has already collected $1.8\times 10^{12}$ kaons stopping in the target. Additional evidence for the rare charged kaon decay $K^+\to\pi^+\nu\bar{\nu}$…

High Energy Physics - Experiment · Physics 2019-08-14 Shaomin Chen

We re-investigate the radiative charged kaon decay K+- --> pi0 e+- nu_e gamma in chiral perturbation theory, merging the chiral expansion with Low's theorem. We thoroughly analyze the precision of the predicted branching ratio relative to…

High Energy Physics - Phenomenology · Physics 2008-11-26 Bastian Kubis , Eike H. Müller , Jürg Gasser , Martin Schmid

The ratio of the leptonic charged kaon decays $R_K= \Gamma(K^{\pm} \to e^{\pm}\nu) / \Gamma(K^{\pm} \to \mu^{\pm}\nu)$ is sensitive to the structure of the week interactions and can be precisely calculated within the Standard Model.…

High Energy Physics - Experiment · Physics 2015-06-23 Venelin Kozhuharov

The KS->gamma gamma decay rate has been measured with the NA48 detector using a high intensity short neutral beam from the CERN SPS. The measured branching ratio BR(KS->gamma gamma)=(2.78+-0.06(stat)+-0.04(syst))x10-6, obtained from…

High Energy Physics - Experiment · Physics 2008-11-26 A. Lai

The final result is presented of the NA48 Experiment performed at CERN SPS neutral kaon beams on the direct CP violation parameter Re(epsilon'/epsilon), as maesured from the decay rates of neutral kaons into two pions. The data collected in…

High Energy Physics - Experiment · Physics 2008-11-26 Wojciech Wislicki

We report the results from a study of ~23 Million K+- ==> pi+- pizero pizero decays recorded by the NA48/2 experiment at the CERN SPS, showing an anomaly in the pizero pizero invariant mass distribution in the region around 2m+, where m+ is…

High Energy Physics - Experiment · Physics 2008-11-26 2 Collaboration , C. Lazzeroni , D. J. Munday , M. W. Slater , S. A. Wotton

The experimental status of the $K \to \pi \nu \bar{\nu}$ search is presented. The $K \to \pi \nu \bar{\nu}$ decay is sensitive to New Physics because it is theoretically pristine and highly suppressed. The $K_L^0 \to \pi^0 \nu \bar{\nu}$…

High Energy Physics - Experiment · Physics 2022-08-04 Chieh Lin

We present measurements of branching fractions and CP-violating asymmetries for neutral B meson decays to two-body final states of charged pions and kaons based on a sample of about 88 million Y(4S)-->BB decays. From a time-independent fit…

High Energy Physics - Experiment · Physics 2009-09-29 The BABAR Collaboration , B. Aubert

Results from the study of the rare decays $K^+\to\pi^+\nu\bar{\nu}$, $K^{+}\rightarrow\pi^{+}\mu^{+}\mu^{-}$ and $K^{+}\rightarrow\pi^{+}\gamma\gamma$ at the NA62 experiment at CERN are interpreted in terms of improved limits for…

High Energy Physics - Experiment · Physics 2025-10-22 NA62 Collaboration

We present an updated discussion of $K\ra\pi \bar{l} l$ decays in a combined framework of chiral perturbation theory and Large--$N_c$ QCD, which assumes the dominance of a minimal narrow resonance structure in the invariant mass dependence…

High Energy Physics - Phenomenology · Physics 2009-11-10 Samuel Friot , David Greynat , Eduardo De Rafael

The branching ratio of the rare decay pi^0 -> e^+e^- has been measured in E799-II, a rare kaon decay experiment using the KTeV detector at Fermilab. The pi^0's were produced in fully-reconstructed K_L -> 3 pi^0 decays in flight. We observed…

High Energy Physics - Experiment · Physics 2008-11-26 KTeV Collaboration

Using a sample of 227 million $\Upsilon(4S) \to B \bar{B}$ events collected with the $BABAR$ detector at the PEP-II $B$ Factory in 1999--2004, we study $B^- \to D^0 K^*(892)^-$ decays where $K^{*-} \to K^0_S \pi^-$ and $D^0 \to K^-\pi^+,…

High Energy Physics - Experiment · Physics 2009-09-29 B. Aubert , BABAR Collaboration

A search for direct CP-violation in K+- --> pi+-pi0pi0 decays based on 47.14 million events has been performed by the NA48/2 experiment at the CERN SPS. The asymmetry in the Dalitz plot linear slopes A_g=(g^+ - g^-)/(g^+ + g^-) is measured…

High Energy Physics - Experiment · Physics 2010-11-05 2 collaboration

We report the first observation of the radiative decay B^0 -> \phi K^0 \gamma using a data sample of 772 x 10^6 B B-bar pairs collected at the \Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We…

High Energy Physics - Experiment · Physics 2019-08-13 H. Sahoo , T. E. Browder