اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدStudy of electromagnetic Dalitz decays $chi_{cJ} rightarrow mu^{+}mu^{-}J/psi$
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Using $4.48 times 10^{8}$ $psi(3686)$ events collected with the BESIII detector, we search for the decays $chi_{cJ} rightarrow mu^{+}mu^{-}J/psi$ through the radiative decays $psi(3686) rightarrow gammachi_{cJ}$, where $J=0,1,2$. The decays $chi_{c1,2} rightarrow mu^{+}mu^{-}J/psi$ are observed, and the corresponding branching fractions are measured to be $mathcal{B}(chi_{c1} rightarrow mu^{+}mu^{-}J/psi) = (2.51 pm 0.18 pm 0.20)times10^{-4}$ and $mathcal{B}(chi_{c2} rightarrow mu^{+}mu^{-}J/psi) = (2.33 pm 0.18 pm 0.29)times10^{-4}$, where the first uncertainty is statistical and the second one systematic. No significant $chi_{c0} rightarrow mu^{+}mu^{-}J/psi$ decay is observed, and the upper limit on the branching fraction is determined to be $2.0times10^{-5}$ at 90% confidence level. Also, we present a study of di-muon invariant mass dependent transition form factor for the decays $chi_{c1,2} rightarrow mu^{+}mu^{-}J/psi$.
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Using $4.479 times 10^{8}$ $psi(3686)$ events collected with the BESIII detector, we search for the decays $psi(3686) rightarrow e^{+}e^{-}chi_{c0,1,2}$ and $chi_{c0,1,2} rightarrow e^{+}e^{-}J/psi$. The decays $psi(3686) rightarrow e^{+}e^{-}chi_{c0
,1,2}$ and $chi_{c0,1,2} rightarrow e^{+}e^{-}J/psi$ are observed for the first time. The measured branching fractions are $mathcal{B}(psi(3686) rightarrow e^{+}e^{-}chi_{c0,1,2}) = (11.7 pm 2.5 pm 1.0)times10^{-4}$, $(8.6 pm 0.3 pm 0.6)times10^{-4}$, $(6.9 pm 0.5 pm 0.6)times10^{-4}$, and $mathcal{B}(chi_{c0,1,2} rightarrow e^{+}e^{-}J/psi) = (1.51 pm 0.30 pm 0.13)times10^{-4}$, $(3.73 pm 0.09 pm 0.25)times10^{-3}$, $(2.48 pm 0.08 pm 0.16)times10^{-3}$. The ratios of the branching fractions $frac{mathcal{B}(psi(3686) rightarrow e^{+}e^{-}chi_{c0,1,2})}{mathcal{B}(psi(3686) rightarrow gammachi_{c0,1,2})}$ and $frac{mathcal{B}(chi_{c0,1,2} rightarrow e^{+}e^{-}J/psi)}{mathcal{B}(chi_{c0,1,2} rightarrow gamma J/psi)}$ are also reported.
Based on a sample of (225.3pm2.8)times 10^{6} J/psi events collected with the BESIII detector, the electromagnetic Dalitz decays of J/psi to P e^+e^-(P=eta/eta/pi^0) are studied. By reconstructing the pseudoscalar mesons in various decay modes, the d
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We measured the branching fractions of the decays $chi_{cJ}toSigma^{-}bar{Sigma}^{+}$ for the first time using the final states $nbar{n}pi^{+}pi^{-}$. The data sample exploited here is $448.1times10^{6}$ $psi(3686)$ events collected with BESIII. We f
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oindent A search for the decays $B^0_{s}rightarrow mu^+ mu^- mu^+ mu^-$ and $B^0 rightarrow mu^+ mu^- mu^+ mu^-$ is performed using data, corresponding to an integrated luminosity of 1.0ensuremath{{,fb}^{-1}}xspace, collected with the LHCb detector i
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