Related papers: Upper Limit on the Decay K+ --> e+ nu mu+ mu-
The decay branching fractions of the three narrow Upsilon resonances to mu+ mu- have been measured by analyzing about 4.3 1/fb e+e- data collected with the CLEO III detector. The branching fraction B(Y(1S) -> mu+ mu-) = (2.49 +- 0.02 +-…
We have searched for the leptonic and radiative leptonic B decays, B^+ -> mu^+ nu, B^+ -> e^+ nu gamma and B^+ -> mu^+ nu gamma. Using a 140 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric e^+ e^- collider, we…
A search for the flavour-changing neutral current decay D0 to mu+mu- is performed in pp collisions at sqrt(s) = 7 TeV using 90 pb-1 of data collected by the CMS experiment at the LHC. No evidence is found for this decay mode. The upper…
A search for the decay $B_{s}^0 \rightarrow \overline{K}{}^{*0}\mu^+\mu^-$ is presented using data sets corresponding to 1.0, 2.0 and 1.6 $\text{fb}^{-1}$ of integrated luminosity collected during $pp$ collisions with the LHCb experiment at…
Using about 3.9 million hadronic Z decays from e+e- collisions recorded by the OPAL detector at LEP at centre-of-mass energies near MZ the branching ratio for the decay D_s -> tau nu_tau has been measured to be (7.0 +/- 2.1(stat) +/- 2.0…
We report the results of a search for the decay B^0 -> e^+ e^-, mu^+ mu^- and e^{+-} mu^{-+} based on an analysis of 78 fb^{-1} of data collected by the Belle detector at KEKB. No candidate events have been found. Upper limits on the…
We have observed a signal for the decay D*+ -> D+ gamma at a significance of 4 standard deviations. From the measured branching ratio B(D*+ -> D+ gamma)/B(D*+ -> D+ pi0)=0.055 +- 0.014 +- 0.010 we find B(D*+ -> D+ gamma)= 0.017 +- 0.004 +-…
We report improved measurements of branching fraction and decay constant fD+ in D+ to mu+nu using 281 pb-1 of data taken on the Psi(3770) resonance with the CLEO-c detector. We extract a relatively precise value for the decay constant of…
In this decade one expects a very significant progress in measuring the branching ratios for several rare $K$ and $B$ decays, in particular for the decays $K^+\to\pi^+\nu\bar\nu$, $K_L\to\pi^0\nu\bar\nu$, $B_s\to\mu^+\mu^+$ and…
The width for the mu decay is calculated in the V-A theory leaving open the possibility of non zero neutrino masses. It is shown that not only the agreement with the experimental data is kept, but the smallness of the experimental error…
A search for the Bs->mumu and Bd->mumu decays is performed in ~300 pb-1 of pp collisions at sqrt(s) = 7 TeV collected by the LHCb experiment at the Large Hadron Collider at CERN. The measured limit on the branching fraction of the Bs->mumu…
An event consistent with the signature expected for the rare kaon decay K+ --> pi+ nu anti-nu has been observed. In the pion momentum region examined, 211<P<230 MeV/c, the backgrounds are estimated to contribute 0.08 +/- 0.03 events. If the…
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…
The rare decays $B_{s(d)} \to \mu^+\mu^-$ play a key role for the testing of the Standard Model. An overview of the most recent theoretical predictions of the corresponding branching ratios is given, emphasizing that the sizable decay width…
We present a model-independent analysis of $K^+\to\pi^+\ell^+\ell^-$ and $K_S\to\pi^0\ell^+\ell^-$ decays, including $K\to 3 \pi$ unitarity corrections and a general decomposition of the dispersive amplitude. From the existing data on…
Motivated by the large like-sign dimuon charge asymmetry observed recently, whose explanation would require an enhanced decay rate of $B_s \to \tau^+ \tau^-$, we explore how large a branching ratio of this decay mode is allowed by the…
Using a large acceptance calorimeter and a stopped pion beam we have made a precise measurement of the rare Pi+ -> Pi0 e+ Nu,(pi_beta) decay branching ratio. We have evaluated the branching ratio by normalizing the number of observed…
The branching fraction of the tau- --> 3h- 2h+ nu decay (h= pi, kaon) is measured with the BaBar detector to be (8.56 +/- 0.05 +/- 0.42)E-04 where the first error is statistical and the second systematic. The observed structure of this…
The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay KL->e+e-mu+mu-, with an estimated background of 0.8 events. The branching ratio of this mode is determined to be 2.69 +/- 0.24 (stat) +/- 0.12 (syst) x…
We have measured the branching fractions of the Cabibbo-suppressed decays $\Lambda^+_c$ $\to$ $\Lambda^{0}$ $K^+$ and $\Lambda^+_c$ $\to$ $\Sigma^0$ $K^+$ %(measured with improved accuracy). relative to the Cabibbo-allowed decay modes…