اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدFirst observation of the isospin violating decay $J/psirightarrow Lambdabar{Sigma}^{0}+c.c.$
218
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Using a sample of $(225.2pm 2.8)times 10^6$ $J/psi$ events collected with the BESIII detector, we present results of a study of $J/psirightarrow gammaLambdabar{Lambda}$ and report the first observation of the isospin violating decay $J/psirightarrowLambdabar{Sigma}^{0}+c.c.$, in which $bar{Sigma}^{0}$ decays to $gamma bar{Lambda}$. The measured branching fractions are $mathcal{B}(J/psirightarrowbar{Lambda}Sigma^{0}$) = $(1.46pm0.11pm0.12) times10^{-5}$ and $mathcal{B}(J/psirightarrowLambdabar{Sigma^{0}}$) = $(1.37pm0.12pm0.11) times10^{-5}$. We search for $Lambda(1520) rightarrow gamma Lambda$ decay, and find no evident signal, and an upper limit for the product branching fraction $mathcal{B}(J/psirightarrowLambdabar{Lambda}(1520)+c.c.)times mathcal{B}(Lambda(1520)rightarrowgammaLambda)<4.1 times10^{-6}$ is set at the 90% confidence level. We also report the observation of $eta_{c}rightarrowLambdabar{Lambda}$ in $J/psi rightarrow gamma eta_{c}$, $eta_{c}rightarrowLambdabar{Lambda}$ and measure the branching fraction $mathcal{B}(eta_{c}rightarrowLambdabar{Lambda}) =(1.16pm0.12 (stat)pm0.19(syst)pm0.28(PDG))times10^{-3}$.
قيم البحث
اقرأ أيضاً
Using E1 radiative transitions $psi(3686) to gammachi_{cJ}$ from a sample of $(448.1 pm 2.9)times10^{6}$ $psi(3686)$ events collected with the BESIII detector, the decays $chi_{cJ}to Sigma^{+}bar{p}K_{S}^{0}+c.c.~(J = 0, 1, 2)$ are studied. The decay
branching fractions are measured to be $mathcal{B}(chi_{c0}to Sigma^{+}bar{p}K_{S}^{0}+c.c.) = (3.52 pm 0.19pm 0.21)times10^{-4}$, $mathcal{B}(chi_{c1}to Sigma^{+}bar{p}K_{S}^{0}+c.c.) = (1.53 pm 0.10pm 0.08)times10^{-4}$, and $mathcal{B}(chi_{c2}to Sigma^{+}bar{p}K_{S}^{0}+c.c.) = (8.25 pm 0.83 pm 0.49)times10^{-5}$, where the first and second uncertainties are the statistical and systematic ones, respectively. No evident intermediate resonances are observed in the studied processes.
Using a sample of 1.31 billion $J/psi$ events collected with the BESIII detector at the BEPCII collider, the decays $J/psi to phi pi^{+}pi^{-}pi^{0}$ and $J/psi to phi pi^{0}pi^{0}pi^{0}$ are investigated. The isospin violating decay $J/psi to phi pi
^{0} f_{0}(980)$ with $f_{0}(980) to pipi$, is observed for the first time. The width of the $f_{0}(980)$ obtained from the dipion mass spectrum is found to be much smaller than the world average value. In the $pi^{0} f_{0}(980)$ mass spectrum, there is evidence of $f_1(1285)$ production. By studying the decay $J/psi to phieta$, the branching fractions of $eta to pi^{+}pi^{-}pi^{0}$ and $eta to pi^{0}pi^{0}pi^{0}$, as well as their ratio, are also measured.
Using $1310.6times10^6$ $J/psi$ and $447.9times10^6$ $psi(3686)$ events collected with the BESIII detector at the BEPCII $e^{+}e^{-}$ collider, the branching fractions and the angular distributions of $J/psi$ and $psi(3686)$ decays to $Lambdabar{Lamb
da}$ and $Sigma^0bar{Sigma}^0$ final states are measured. The branching fractions are in agreement with, and much more precise than, the averages of previously published results. The polar angular distributions of $psi(3686)$ decays are measured for the first time, while those of $J/psi$ decays are measured with much improved precision. In addition, the ratios of branching fractions $frac{mathcal{B}(psi(3686)toLambdabar{Lambda})}{mathcal{B}(J/psitoLambdabar{Lambda})}$ and $frac{mathcal{B}(psi(3686)toSigma^0bar{Sigma}^0)}{mathcal{B}(J/psitoSigma^0bar{Sigma}^0)}$ are determined to test the 12% rule.
Using data samples collected at center of mass energies of $sqrt{s}$ = 4.009, 4.226, 4.257, 4.358, 4.416 and 4.599 GeV with the BESIII detector operating at the BEPCII storage ring, we search for the isospin violating decay $Y(4260)rightarrow J/psi e
ta pi^{0}$. No signal is observed, and upper limits on the cross section $sigma(e^{+}e^{-}rightarrow J/psi eta pi^{0})$ at the 90% confidence level are determined to be 3.6, 1.7, 2.4, 1.4, 0.9 and 1.9 pb, respectively.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
