اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدPrecision measurements of branching fractions for $ psitopi^0 Jpsi$ and $eta Jpsi$
99
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We present a precision study of the $psiptopi^0 J/psi$ and $eta J/psi$ decay modes. The measurements are obtained using $106times10^6$ $psi$ events accumulated with the BESIII detector at the BEPCII $ee$ collider operating at a center-of-mass energy corresponding to the $psip$ mass. We obtain $mathcal{B}(psiptopi^0 J/psi)=(1.26pm0.02{rm (stat.)}pm0.03{rm (syst.)})times 10^{-3}$ and $mathcal{B}(psiptoeta J/psi)=(33.75pm0.17{rm (stat.)}pm0.86{rm (syst.)})times 10^{-3}$. The branching fraction ratio $R=frac{mathcal{B}(psiptopi^0 J/psi)}{mathcal{B}(psiptoeta J/psi)}$ is determined to be $(3.74pm0.06 {rm(stat.)}pm0.04 {rm(syst.)})times 10^{-2}$. The precision of these measurements of $mathcal{B}(psiptopi^{0} J/psi)$ and $R$ represent a significant improvement over previously published values.
قيم البحث
اقرأ أيضاً
Based on a sample of $(1310.6 pm 7.0) times 10^6~J/psi$ events collected with the BESIII detector, we present measurements of $J/psi$ and $eta^prime$ absolute branching fractions using the process $J/psirightarrowgammaeta^prime$. By analyzing events
where the radiative photon converts into an $e^+e^-$ pair, the branching fraction for $J/psi rightarrow gamma eta^prime$ is measured to be $(5.27pm0.03pm0.05)times 10^{-3}$. The absolute branching fractions of the five dominant decay channels of the $eta^prime$ are then measured independently for the first time and are determined to be $mathcal{B}(eta^prime rightarrow gamma pi^{+} pi^{-})$ = (29.90$pm$0.03$pm$0.55)%, $mathcal{B}(eta^prime rightarrow eta pi^{+} pi^{-})$ = (41.24$pm$0.08$pm$1.24)%, $mathcal{B}(eta^prime rightarrow eta pi^{0} pi^{0})$ = (21.36$pm$0.10$pm$0.92)%, $mathcal{B}(eta^prime rightarrow gamma omega)$ = (2.489$pm$0.018$pm$0.074)%, and $mathcal{B}(eta^prime rightarrow gamma gamma)$ = (2.331$pm$0.012$pm$0.035)%, where the first uncertainties are statistical and the second systematic.
Using 482 pb$^{-1}$ of data taken at $sqrt{s}=4.009$ GeV, we measure the branching fractions of the decays of $D^{*0}$ into $D^0pi^0$ and $D^0gamma$ to be $BR(D^{*0} to D^0pi^0)=(65.5pm 0.8pm 0.5)%$ and $BR(D^{*0} to D^0gamma)=(34.5pm 0.8pm 0.5)%$ re
spectively, by assuming that the $D^{*0}$ decays only into these two modes. The ratio of the two branching fractions is $BR(D^{*0} to D^0pi^0)/BR(D^{*0} to D^0gamma) =1.90pm 0.07pm 0.05$, which is independent of the assumption made above. The first uncertainties are statistical and the second ones systematic. The precision is improved by a factor of three compared to the present world average values.
By analyzing a data sample of 2.93 fb$^{-1}$ collected at $sqrt s=$ 3.773 GeV with the BESIII detector operated at the BEPCII storage rings, we measure the branching fractions ${mathcal B}(D^0toomegaeta)=(2.15pm0.17_{rm stat.}pm0.15_{rm sys.})times 1
0^{-3}$, ${mathcal B}(D^0toetapi^0)=(0.58pm0.05_{rm stat.}pm0.05_{rm sys.})times 10^{-3}$, ${mathcal B}(D^0toeta^primepi^0)=(0.93pm0.11_{rm stat.}pm0.09_{rm sys.})times 10^{-3}$, ${mathcal B}(D^0toetaeta)=(2.20pm0.07_{rm stat.}pm0.06_{rm sys.})times 10^{-3}$ and ${mathcal B}(D^0toeta^primeeta)=(0.94pm0.25_{rm stat.}pm0.11_{rm sys.})times 10^{-3}$. We note that ${mathcal B}(D^0to omegaeta)$ is measured for the first time and that ${mathcal B}(D^0to etaeta)$ is measured with much improved precision.
Using a sample of 225.3 million $jpsi$ events collected with the BESIII detector at the BEPCII $e^+e^-$ collider in 2009, searches for the decays of $eta$ and $eta^primetopi^+ e^- bar{ u}_e +c.c.$ in $jpsi to phi eta$ and $phieta^prime$ are performed
. The $phi$ signals, which are reconstructed in $K^+K^-$ final states, are used to tag $eta$ and $eta^prime$ semileptonic decays. No signals are observed for either $eta$ or $eta^prime$, and upper limits at the 90% confidence level are determined to be $7.3times 10^{-4}$ and $5.0times 10^{-4}$ for the ratios $frac{{mathcal B}(etato pi^+ e^- bar{ u}_e +c.c.)}{{mathcal B}(eta to pippimpiz)}$ and $frac{{mathcal B}(eta^primeto pi^+ e^-bar{ u}_e +c.c.)}{{mathcal B}(eta^prime to pippimeta)}$, respectively. These are the first upper limit values determined for $eta$ and $eta^prime$ semileptonic weak decays.
We report measurements of the branching fractions of singly Cabibbo-suppressed decays $Lambda_c^+ to p eta$ and $Lambda_c^+ to p pi^0$ using the full Belle data sample corresponding to an integrated luminosity of 980.6 $rm fb^{-1}$. The data were col
lected by the Belle detector at the KEKB $e^{+}$$e^{-}$ asymmetric-energy collider. A clear $Lambda_c^+$ signal is seen in the invariant mass distribution of $p eta$. The signal yield of the $Lambda_c^+ to p eta$ process is $7734 pm 263$; from this, we measure the ratio of branching fractions ${cal B}(Lambda_c^+ to p eta)/{cal B}(Lambda_c^+ to p K^- pi^+) = (2.258 pm 0. 077(rm stat. ) pm 0.136(rm syst. ))times 10^{-2}$, from which we infer the branching fraction ${cal B}(Lambda_c^+ to p eta) = (1.42 pm 0.05(rm stat.) pm 0.11(rm syst.)) times 10^{-3}$. In addition, no significant signal for $Lambda_c^+ to p pi^0$ is found so an upper limit on the branching fraction of ${cal B}(Lambda_c^+ to p pi^0)<8.0 times 10^{-5}$ at 90% credibility level is set, more than three times better than the best current upper limit.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
