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Register a new userSearch for the $eta_c(2S)/h_cto pbar{p}$ decays and measurements of the $chi_{cJ}to pbar{p}$ branching fractions
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Using a sample of $1.06times10^{8}~psi(3686)$ events collected with the BESIII detector at BEPCII, the decays $eta_{c}(2S)to pbar{p}$ and $h_{c}to pbar{p}$ are searched for, where $eta_c(2S)$ and $h_c$ are reconstructed in the decay chains $psi(3686)togammaeta_{c}(2S)$, $eta_{c}(2S)to pbar{p}$ and $psi(3686)topi^{0}h_{c}$, $h_{c}to pbar{p}$, respectively. No significant signals are observed. The upper limits of the product branching fractions are determined to be $mathcal{B}(psi(3686)togammaeta_c(2S))timesmathcal{B}(eta_{c}(2S)to pbar{p})<1.4times10^{-6}$ and $mathcal{B}(psi(3686)topi^0h_c)timesmathcal{B}(h_{c}to pbar{p})<1.3times10^{-7}$ at the 90% C.L.. The branching fractions for $chi_{cJ}to pbar{p}$ $(J=0,~1,~2)$ are also measured to be $(24.5pm0.8pm1.3,~8.6pm0.5pm0.5,~8.4pm0.5pm0.5)times10^{-5}$, which are the worlds most precise measurements.
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The reaction pbar p -> pbar p pi+ pi- has been studied with high statistics at CERN-LEAR with incident pbar momenta from 1.65 to 2.0 GeV/c by the JETSET (PS202) experiment. The aim of this paper is to search for narrow resonances decaying to pbar p. No evidence for such structures is found. In particular, an upper limit for the production of a 2.02 GeV state with a width of Gamma = 20 MeV, having been seen in other hadroproduction experiments, is established. Our results restrict the cross section for such a peak to be below 200 nb at the 95% confidence level.
The branching fractions of the decay $B^{+} to p bar p K^{+}$ for different intermediate states are measured using data, corresponding to an integrated luminosity of $1.0 fb^{-1}$, collected by the LHCb experiment. The total branching fraction, its charmless component $(M_{pbar p} <2.85 {GeV/}c^{2})$ and the branching fractions via the resonant $cbar c$ states $eta_{c}(1S)$ and $psi(2S)$ relative to the decay via a $J/psi$ intermediate state are {align*} frac{{mathcal B}(B^{+} to p bar p K^{+})_{total}}{{mathcal B}(B^{+} to J/psi K^{+} to p bar p K^{+})}=& , 4.91 pm 0.19 , {(rm stat)} pm 0.14 , {(rm syst)}, frac{{mathcal B}(B^{+} to p bar p K^{+})_{M_{pbar p} <2.85 {GeV/}c^{2}}}{{mathcal B}(B^{+} to J/psi K^{+} to p bar p K^{+})}=& , 2.02 pm 0.10 , {(rm stat)}pm 0.08 , {(rm syst)}, frac{{mathcal B} (B^{+} to eta_{c}(1S) K^{+} to p bar p K^{+})}{{mathcal B}(B^{+} to J/psi K^{+} to p bar p K^{+})} = & , 0.578 pm 0.035 , {(rm stat)} pm 0.027 , {(rm syst)}, frac{{mathcal B} (B^{+} to psi(2S) K^{+} to p bar p K^{+})}{{mathcal B}(B^{+} to J/psi K^{+} to p bar p K^{+})}=& , 0.080 pm 0.012 , {(rm stat)} pm 0.009 , {(rm syst)}. {align*} Upper limits on the $B^{+}$ branching fractions into the $eta_{c}(2S)$ meson and into the charmonium-like states X(3872) and X(3915) are also obtained.
Using a data sample of $1.06 times 10^{8}$ $psip$ events collected with the BESIII detector in 2009, the branching fractions of $chi_{cJ}to pbar{n}pi^{-}$ and $chi_{cJ}to pbar{n}pi^{-}pi^{0}$ ($J$=0,1,2) are measured{Throughout the text, inclusion of charge conjugate modes is implied if not stated otherwise.}. The results for $chi_{c0}to pbar{n}pi^{-}$ and $chi_{c2}to pbar{n}pi^{-}$ are consistent with, but much more precise than those of previous measurements. The decays of $chi_{c1}to pbar{n}pi^{-}$ and $chi_{cJ}to pbar{n}pi^{-}pi^{0}$ are observed for the first time.
We find evidence for the semileptonic baryonic decay $B^-to pbar pell^-bar u_ell$ ($ell=e,mu$), based on a data sample of 772 million $Bbar B$ pairs collected at the $Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy electron-positron collider. A neural-network based hadronic $B$-meson tagging method is used in this study. The branching fraction of $B^-to pbar pell^-bar u_ell$ is measured to be $(5.8^{+2.4}_{-2.1}textrm{(stat.)}pm 0.9textrm{(syst.)})times 10^{-6}$ with a significance of 3.2$sigma$, where lepton universality is assumed. We also estimate the corresponding upper limit: $mathcal{B}(B^-to pbar pell^-bar u_ell) < 9.6times 10^{-6}$ at the 90% confidence level. This measurement helps constrain the baryonic transition form factor in B 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 collected 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.
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