No Arabic abstract
By analyzing $4.48times10^8$ $psi(3686)$ events collected with the BESIII detector, we observe the decays $chi_{cJ} to n K^0_SbarLambda + c.c.$ ($J=0$, 1, 2) for the first time, via the radiative transition $psi(3686) to gamma chi_{cJ}$. The branching fractions are determined to be $(6.67 pm 0.26_{rm stat} pm 0.41_{rm syst})times10^{-4}$, $(1.71 pm 0.12_{rm stat} pm 0.12_{rm syst})times10^{-4}$, and $(3.66 pm 0.17_{rm stat} pm 0.23_{rm syst})times10^{-4}$ for $J=0$, 1, and 2, respectively.
The decays $chi_{cJ}toSigma^{0}bar{p}K^{+}+{rm c.c.}~(J = 0, 1, 2)$ are studied via the radiative transition $psi(3686)togammachi_{cJ}$ based on a data sample of $(448.1 pm 2.9)times10^{6}$ $psi(3686)$ events collected with the BESIII detector. The branching fractions of $chi_{cJ}toSigma^{0}bar{p}K^{+}+{rm c.c.}~(J = 0, 1, 2)$ are measured to be $(3.03 pm 0.12pm 0.15)times10^{-4}$, $(1.46 pm 0.07pm 0.07)times10^{-4}$, and $(0.91 pm 0.06pm 0.05)times10^{-4}$, respectively, where the first uncertainties are statistical and the second are systematic. In addition, no evident structure is found for excited baryon resonances on the two-body subsystems with the limited statistics.
By analyzing $(448.1pm2.9)times10^6$ $psi(3686)$ events collected with the BESIII detector operating at the BEPCII collider, the decays of $chi_{cJ} to 4K_S^0$ ($J=0,1,2$) are observed for the first time with statistical significances of 26.5$sigma$, 5.9$sigma$ and 11.4$sigma$, respectively. The product branching fractions of $psi(3686)togammachi_{cJ}$, $chi_{cJ}to4K_{S}^{0}$ are presented and the branching fractions of $chi_{cJ}to4K_{S}^{0}$ decays are determined to be $mathcal{B}_{chi_{c0}to 4K_S^0}$=$(5.76pm0.34pm0.38)$$times10^{-4}$, $mathcal{B}_{chi_{c1}to 4K_S^0}$=$(0.35pm0.09pm0.03)$$times10^{-4}$ and $mathcal{B}_{chi_{c2}to 4K_S^0}$=$(1.14pm0.15pm0.08)$$times10^{-4}$, where the first uncertainties are statistical and the second are systematic, respectively.
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 data sample of $(448.1pm2.9)times10^{6}$ $psi(3686)$ decays collected by the BESIII detector at the Beijing Electron Positron Collider (BEPCII), we observe the decays $chi_{cJ}to phiphieta~(J=0,~1,~2)$, where the $chi_{cJ}$ are produced via the radiative processes $psi(3686)togammachi_{cJ}$. The branching fractions are measured to be $mathcal B(chi_{c0}tophiphieta)=(8.41pm0.74pm0.62)times10^{-4}$, $mathcal B(chi_{c1}tophiphieta)=(2.96pm0.43pm0.22)times 10^{-4}$, and $mathcal B(chi_{c2} to phiphieta)=(5.33pm0.52pm0.39) times 10^{-4}$, where the first uncertainties are statistical and the second are systematic. We also search for intermediate states in the $phiphi$ or $etaphi$ combinations, but no significant structure is seen due to the limited statistics.
The first observation of the decays $Lambda_b^0 to chi_{c1} p K^-$ and $Lambda_b^0 to chi_{c2} p K^-$ is reported using a data sample corresponding to an integrated luminosity of $3.0$ fb$^{-1}$, collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies of 7 and 8 TeV. The following ratios of branching fractions are measured begin{eqnarray*} frac{{cal B}(Lambda_b^0 to chi_{c1} p K^-)}{{cal B}(Lambda_b^0 to J/psi p K^-)} = 0.242 pm 0.014 pm 0.013 pm 0.009, frac{{cal B}(Lambda_b^0 to chi_{c2} p K^-)}{{cal B}(Lambda_b^0 to J/psi p K^-)} = 0.248 pm 0.020 pm 0.014 pm 0.009, frac{{cal B}(Lambda_b^0 to chi_{c2} p K^-)}{{cal B}(Lambda_b^0 to chi_{c1} p K^-)} = 1.02 pm 0.10 pm 0.02 pm 0.05, end{eqnarray*} where the first uncertainty is statistical, the second systematic and the third due to the uncertainty on the branching fractions of the $chi_{c1}to J/psigamma$ and $chi_{c2} to J/psigamma$ decays. Using both decay modes, the mass of the $Lambda_b^0$ baryon is also measured to be $m_{Lambda_b^0} = 5619.44 pm 0.28 pm 0.26$ MeV/$c^2$, where the first and second uncertainties are statistical and systematic, respectively.