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تسجيل مستخدم جديدStatus of the Study of the Rare Decay K^+ to pi^+ u bar u at BNL
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تأليف
T. K. Komatsubara
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The current status of the experimental study of the rare kaon decay K^+ to pi^+ u bar u at Brookhaven National Laboratory (BNL) by the E787 and E949 collaborations is reported.
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An upper limit on the branching ratio for the decay $K^+ ! rightarrow ! pi^+ u overline{ u}$ is set at $2.4 times 10^{-9}$ at the 90% C.L. using pions in the kinematic region $214~{rm MeV}/c < P_pi < 231~{rm MeV}/c$. An upper limit of $5.2 times 10^
{-10}$ is found on the branching ratio for decays $K^+ ! rightarrow ! pi^+ X^0$, where $X^0$ is any massless, weakly interacting neutral particle. Limits are also set for cases where $M_{X^0}>0$.
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Using data collected by the fixed target Fermilab experiment FOCUS, we present several first measurements for the semileptonic decay $D^0 to bar{K}^0pi^-mu^+ u$. Using a model that includes a $bar{K}^0 pi^-$ S-wave component, we measure the form fact
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