We present a search for f_J(2220) production in radiative J/psi -> gamma f_J(2220) decays using 460 fb-1 of data collected with the BABAR detector at the SLAC PEP-II e+e- collider. The f_J(2220) is searched for in the decays to K+K- and KsKs. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/psi -> gamma f_J(2220), f_J(2220) -> K+K- and J/psi -> gamma f_J(2220), f_J(2220) -> KsKs as a function of spin and helicity are set at the level of 10-5. These values are below the central values reported by the Mark III experiment.
We studied the decay psi(2S) to gamma eta_c(2S) with 25.9 million psi(2S) events collected with the CLEO-c detector. No psi(2S) to gamma eta_c(2S) decays were observed in any of the eleven exclusive eta_c(2S) decay modes studied. The product branching fraction upper limits were determined for all modes. The 90% confidence level upper limit of branching fraction of psi(2S) to gamma eta_c (2S) was obtained.
Using 24.5 million psi(2S) decays collected with the CLEO-c detector at CESR we present the most precise measurements of magnetic dipole transitions in the charmonium system. We measure B(psi(2S)->gamma eta_c) = (4.32+/-0.16+/-0.60)x10^-3, B(J/psi->gamma eta_c)/B(psi(2S)->gamma eta_c) = 4.59+/-0.23+/-0.64, and B(J/psi->gamma eta_c) = (1.98+/-0.09+/-0.30)%. We observe a distortion in the eta_c line shape due to the photon-energy dependence of the magnetic dipole transition rate. We find that measurements of the eta_c mass are sensitive to the line shape, suggesting an explanation for the discre…
The previous results of J/psi radiative decays from MARKIII, DM2, Crystal Ball and BESI are briefly reviewed in this talk. The main part of this talk focuses on presenting the recent results from BESII 58 million J/psi data, including the Partial Wave Analysis (PWA) results, the measurement of eta_c mass, as well as search for some interesting states.
We observe a narrow enhancement near 2mp in the invariant mass spectrum of ppbar pairs from radiative J/psi-->gamma ppbar decays. The enhancement can be fit with either an S- or P-wave Breit Wigner fuction. In the case of the S-wave fit, the peak mass is below the 2mp threshold and the full width is less than 30 MeV. These mass and width values are not consistent with the properties of any known meson resonance.
Using a sample of 14 million $\psip$ events collected with the BESII detector, branching fractions or upper limits on the branching fractions of $\psip$ decays into $γ\ppb$, $γ2(\pip\pim)$, $γ\kskp$, $γ\kap\kam\pip\pim$, $γ\kstarz\kam\pip+c.c.$, $γ\kstarz \kstarzb$, $γ\pip\pim\ppb$, $\gamma2(\kap\kam)$, $\gamma3(\pip\pim)$ and $\gamma2(\pip\pim)\kap\kam$ with hadron invariant mass less than 2.9$\gev/c^2$ are reported. We also report branching fractions of $\psip$ decays into $γ\ppb\piz$, $\ppb\piz\piz$, $2(\pip\pim)\piz$, $ω\pp$, $ωf_2(1270)$, $b_1^\pmπ^\mp$, $\piz\kskp$, $K^\pmρ^\mp\ks$, $\pi…
Using 14 million psi(2S) events accumulated at the BESII detector, we report first measurements of branching fractions or upper limits for psi(2S) decays into gamma ppbar, gamma 2(pi^+pi^-), gamma K_s K^-pi^++c.c., gamma K^+ K^- pi^+pi^-, gamma K^{*0} K^- pi^+ +c.c., gamma K^{*0}\bar K^{*0}, gamma pi^+pi^- p pbar, gamma 2(K^+K^-), gamma 3(pi^+pi^-), and gamma 2(pi^+pi^-)K^+K^- with the invariant mass of hadrons below 2.9GeV/c^2. We also report branching fractions of psi(2S) decays into 2(pi^+pi^-) pi^0, omega pi^+pi^-, omega f_2(1270), b_1^\pm pi^\mp, and pi^0 2(pi^+pi^-) K^+K^-.
Using e+e- collision data taken with the CLEO-c detector at the Cornell Electron Storage Ring, we have investigated the direct photon spectrum in the decay psi(2S)->gamma+gluon+gluon. We determine the ratio R of that inclusive direct photon decay rate to that of the three-gluon decay rate psi(2S)->3-gluon to be R(z>0.4)=0.070+/-0.002+/-0.019+/-0.011, with z defined as the scaled photon energy relative to the beam energy. The errors shown are statistical, systematic, and that due to the uncertainty in the input branching fractions used to extract the ratio, respectively. This R value is approxi…
Using a data sample containing 1.06x10^8 psi' events collected with the BESIII detector at the BEPCII electron-positron collider, we search for a light exotic particle X in the process psi' -> pi^+ pi^- J/psi, J/psi -> gamma X, X -> mu^+ mu^-. This light particle X could be a Higgs-like boson A^0, a spin-1 U boson, or a pseudoscalar sgoldstino particle. In this analysis, we find no evidence for any mu^+mu^- mass peak between the mass threshold and 3.0 GeV/c^2. We set 90%-confidence-level upper limits on the product-branching fractions for J/psi -> gamma A^0, A^0 -> mu^+ mu^- which range from 4…
We observe a narrow enhancement near 2m_p in the invariant mass spectrum of p\bar{p} pairs from radiative J/psi-->gamma p\bar{p} decays. No similar structure is seen in J/psi-->pi0 p\bar{p} decays. The results are based on an analysis of a 58 million event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit either with an S- or P-wave Breit Wigner resonance function; in the case of the S-wave fit, the peak mass is below 2m_p at M=1859 +3 -10(stat) +5 -25 (syst) MeV/c**2 and the total width is Gamma < 30 MeV/c**2, at t…
Using data taken with the CLEO-c detector at the Cornell Electron Storage Ring, we have investigated the direct photon momentum spectrum in the decay J/psi->gamma+gluon+gluon, via the 'tagged' process: e+e- -> psi(2S); psi(2S)->J/psi pi+pi-; J/psi->photon + X. Including contributions from two-body radiative decay processes, we find the ratio of the inclusive direct photon branching fraction to that of the dominant three-gluon branching fraction to be R=0.137+/-0.001+/-0.016+/-0.004, where the errors shown are statistical, systematic, and the model-dependent uncertainty related to the extrapola…
A partial wave analysis of the $p \bar{p}$ mass-threshold enhancement in the reaction $J/ψ\rightarrowγp\bar{p}$ is used to determine: its $J^{PC}$ quantum numbers to be $0^{-+}$; its peak mass to be below threshold at $M=1832^{+19}_{-5} {\rm(stat.)}^{+18}_{-17} {\rm (syst.)}\pm19 {\rm (model)} {\rm MeV}/c^2$; and its total width to be $Γ<76 {\rm MeV}/c^2$ at the 90% C.L. The product branching ratio is measured to be $B(J/ψ\rightarrowγX(p\bar{p}))B(X(p\bar{p})\rightarrow p\bar{p})=(9.0^{+0.4}_{-1.1} {\rm (stat.)}^{+1.5}_{-5.0} {\rm (syst.)}\pm2.3 {\rm (model)})\times10^{-5}$. A similar analysis…
We report study of B+- to J/psi eta K+- decays at Belle. In this analysis we search for X(3872) as well as other narrow resonances in the J/psi eta final state.
We present an effective field theory based extraction of the eta_c mass and width from a recent measurement by CLEO of the photon line shape in J/Psi -> eta_c gamma decay.
Using 14.0\times 10^6 ψ(2S) events collected with the BES-II detector, the C-parity violating process J/psi->gamma gamma via psi(2S)->pi+pi- J/psi is studied. We determine a new upper limit for the J/psi->gamma gamma branching ratio of B(J/psi->gamma gamma)<2.2\times 10^{-5} at the 90% C.L., which is about 20 times lower than the previous measurement.
We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi --> D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7 J/Psi events collected with the BESII detector at the BEPC. No excess of signal above background is observed, and 90% confidence level upper limits on the branching fractions are set: B(J/Psi --> Ds- e+ nu_e + c.c.)<4.8*10^-5, B(J/Psi --> D- e+ nu_e + c.c.)<1.2*10^-5, and B(J/Psi --> D0bar e+ e- + c.c.)<1.1*10^-5
The CP violating processes J/psi-->K_S K_S and psi(2S)-->K_S K_S are searched for using samples of 58 million J/psi and 14 million psi(2S) events collected with the Beijing Spectrometer at the Beijing Electron Positron Collider. No signal is observed, and upper limits on the decay branching ratios are determined to be BR(J/psi-->K_S K_S) < 1.0x10^{-6} and BR(psi(2S)-->K_S K_S) < 4.6x10^{-6} at the 95% confidence level.
We present a search for direct CP violation in B+- -> J/psi K+- and B+- -> psi(2S) K+- decays. In a sample of 9.7 million B meson pairs collected with the CLEO detector, we have fully reconstructed 534 B+- -> J/psi K+- and 120 B+- -> psi(2S) K+- decays with very low background. We have measured the CP-violating charge asymmetry to be (+1.8+-4.3[stat]+-0.4[syst])% for B+- -> J/psi K+- and (+2.0+-9.1[stat]+-1.0[syst])% for B+- -> psi(2S) K+-.
We report the results of searches for B+ -> J/psi eta' K+ and B0 -> J/psi eta' Ks0 decays, using a sample of 388 x 10^6 BBbar pairs collected with the Belle detector at the Upsilon(4S) resonance. No statistically significant signal is found for either of the two decay modes and upper limits for the branching fractions are determined to be B(B+ -> J/psi eta' K+) < 8.8 x 10^-5 and B(B0 -> J/psi eta' Ks0) < 2.5 x 10^-5 at 90% confidence level.
K_S K_L from psi'' decays is searched for using the psi'' data collected by BESII at BEPC, the upper limit of the branching fraction is determined to be B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is compared with the prediction of the S- and D-wave mixing model of the charmonia, based on the measurements of the branching fractions of J/psi-->K_S K_L and psi'-->K_S K_L.
We report the observation of B- -> J/psi Lambda pbar and searches for B- -> J/psi Sigma0 pbar and B0 -> J/psi p pbar decays, using a sample of 275 million BBbar pairs collected with the Belle detector at the Upsilon(4S) resonance. We observe a signal of 17.2 +/- 4.1 events with a significance of 11.1sigma and obtain a branching fraction of B(B- -> J/psi Lambda pbar) = [11.6 +/- 2.8 (stat.) +1.8 -2.3(sys.)] x 10^-6. No signal is found for either of the two decay modes, B- -> J/psi Sigma0 pbar and B0 -> J/psi p pbar, and upper limits for the branching fractions are determined to be B(B- -> J/psi…
We report the results of a search for the decay modes B0 -> J/psi D0bar and B+ -> J/psi D0bar pi+. The analysis is based on 140 $\rm fb^{-1}$ of data accumulated by the Belle detector at the KEKB asymmetric-energy $e^{+} e^{-}$ collider. No significant signals are observed and we determine the branching fraction upper limits B(B0 -> J/psi D0bar) < 2.0 10^{-5} and B(B+ -> J/psi D0bar pi+) < 2.5 10^{-5} at 90% confidence level. These results rule out the explanation of the excess in the low momentum region of the inclusive J/psi spectrum as intrinsic charm content in the B meson. The branching f…
We have studied the B^+/- --> J/psi pi^+/- and B^+/- --> J/psi K^+/- decays using a 20.7 fb-1 data set collected with the BABAR detector. We observe a signal of 51+/-10 B^+/- --> J/psi pi^+/- events and determine the ratio BF(B^+/- --> J/psi pi^+/-)/BF(B^+/- --> J/psi K^+/-) to be [3.91 +/- 0.78 (stat.) +/- 0.19 (syst.)]%. The CP-violating charge asymmetries for the B^+/- --> J/psi pi^+/- and B^+/- --> J/psi K^+/- decays are determined to be A_pi = 0.01 +/- 0.22 (stat.) +/- 0.01 (syst.) and A_K = 0.003 +/- 0.030 (stat.) +/- 0.004 (syst.).
Using data collected at the psi(3770) resonance with the CLEO-c detector at the Cornell e^+e^- storage ring, we present searches for 25 charmless decay modes of the psi(3770), mostly multibody final states. No evidence for charmless decays is found.
We report a search for B -> J/psi D decays, based on a sample of 124 10^6 BBbar events collected with the BABAR detector at the PEP-II storage ring of the Stanford Linear Accelerator Center. No significant signal is found. We obtain upper limits on the branching fractions of 1.3 10^{-5} for B0 -> J/psi D0bar and 1.2 10^{-4} for B+ -> J/psi D+ at 90% confidence level.
Using the current world's largest data sample of psi(3770) decays, we present results of a search for the non-DDbar decay psi(3770) -> KsKl. We find no signal, and obtain an upper limit of Sigma(psi(3770) -> KsKl) < 0.07 pb at 90% confidence level (CL). Our result tests a theoretical prediction for the upper bound on B(psi(3770) -> KsKl) based on a charmonia-mixing model.
We study B^+/- --> J/psi pi^+/- and B^+/- --> J/psi K^+/- decays in a sample of about 89 million BB~ pairs collected with the BABAR detector at the PEP-II asymmetric B-factory at SLAC. We observe a signal of 244 +/- 20 B^+/- --> J/psi pi^+/- events and determine the ratio BF(B^+/- --> J/psi pi^+/-)/BF(B^+/- --> J/psi K^+/-) to be [5.37 +/- 0.45 (stat.) +/- 0.11 (syst)]%. The charge asymmetries for the B^+/- --> J/psi pi^+/- and B^+/- --> J/psi K^+/- decays are determined to be A_pi = 0.123 +/- 0.085 (stat.) +/- 0.004 (syst.) and A_K = 0.030 +/- 0.015 (stat.) +/- 0.006 (syst.), respectively.
Recent results from BES and CLEOc experiments on charmonium decays using J/psi, psi' and psi'' data samples collected in e+e- annihilation are reviewed, including the measurement of the relative phase between strong and electromagnetic decays of psi', the study of the ``rho pi puzzle'' in J/psi and psi' decays, and the search for the non-DDbar decays of psi''. The decays of chi_cJ produced in psi' radiative transition are also reviewed. These new results shed light on the understanding of QCD.
We search for a light Higgs boson $A^0$ in the fully reconstructed decay chain of $J/ψ\rightarrow γA^0$, $A^0 \rightarrow μ^+μ^-$ using $(225.0\pm2.8)\times10^6$ $J/ψ$ events collected by the BESIII experiment. The $A^0$ is a hypothetical CP-odd light Higgs boson predicted by many extensions of the Standard Model including two spin-0 doublets plus an extra singlet. We find no evidence for $A^0$ production and set $90\%$ confidence-level upper limits on the product branching fraction $\mathcal{B}(J/ψ\rightarrow γA^0) \times \mathcal{B}(A^0 \rightarrow μ^+μ^-)$ in the range of $(2.8-495.3)\times…
Using data acquired with the CLEO detector at the CESR e+e- collider at sqrt{s} = 3.773 GeV, we measure the cross section for the radiative return process e+e- --> gamma J/psi, J/psi --> mu+mu-, resulting in B(J/psi --> mu+mu-) x Gamma_ee(J/psi) = 0.3384 +- 0.0058 +- 0.0071 keV, Gamma_ee(J/psi) = 5.68 +- 0.11 +- 0.13 keV, and Gamma_tot(J/psi) = 95.5 +- 2.4 +- 2.4 keV, in which the errors are statistical and systematic, respectively. We also determine the ratio Gamma_ee[psi(2S)] / Gamma_ee(J/psi) = 0.45 +- 0.01 +- 0.02.
We present the results of a search for the radiative decay B0 --> J/psi gamma in a data set containing 123 million Y(4S)--> B B-bar decays, collected by the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring at SLAC. We find no evidence for a signal and place an upper limit of B(B0 --> J/psi gamma) < 1.6 x 10^-6 at 90% confidence level.
A search for J/psi radiative decay to weakly interacting neutral final states was performed using the CLEO-c detector at CESR. A total of 3.7 x 10^{6} tagged J/psi events was collected at the psi(2S) resonance and used to study the decay J/psi -> gamma+X, where X is a narrow state that is invisible to the detector. No significant signal was observed and upper limits on the branching fraction were set for masses m_X up to 960 MeV/c^2. The upper limit corresponding to m_X=0 is 4.3x 10^{-6} at the 90% confidence level.
We report a search for the decay psi(2S) -> gamma eta_c(2S) in a sample of 25.9 million psi(2S) events collected with the CLEO-c detector. No signals are observed in any of the 11 exclusive eta_c(2S) decay modes studied, or in their sum. Product branching fraction upper limits are determined as a function of Gamma[eta_c(2S)] for the 11 individual modes.
Using 5.63 pb^-1 of data accumulated at the psi(2S) resonance with the CLEO III and CLEO-c detectors corresponding to 3.08 million psi(2S) decays, a search is performed for the decay psi(2S) -> eta_c pi^+pi^-pi^0 to test a theoretical prediction based upon the assumption that the c \bar c pair in the psi(2S) does not annihilate directly into three gluons but rather survives before annihilating. No signal is observed, and a combined upper limit from six eta_c decay modes is determined to be B(psi(2S) -> eta_c pi^+pi^-pi^0) < 1.0 x 10^-3 at 90% C.L. This upper limit is about an order of magnitud…
Recent results from BES and CLEOc experiments on hadron spectroscopy and charmonium decays using J/psi, psi' and psi'' data samples collected in e+e- annihilation are reviewed, including the observation of X(1835) in J/psi --> gamma pi+ pi- eta', study of the scalar particles in J/psi radiative and hadronic decays, as well as in chi_c0 hadronic decays, and the study of the ``ρπpuzzle'' in J/psi, psi', and psi'' decays. We also make a few comments on partial wave analysis, and the study of the ρπpuzzle.
We search for a charged partner of the X(3872) in the decay B --> X- K, X- --> J/psi pi- pi0, using 234 million BBbar events collected at the Y(4S) resonance with the BaBar detector at the PEP-II e+e- asymmetric-energy storage ring. The resulting product branching fraction upper limits are BR(B0 --> X- K+, X- --> J/psi pi- pi0) < 5.4 x 10(-6) and BR(B- --> X- K0bar,X- --> J/psi pi- pi0) < 22 x 10(-6) at the 90% confidence level.
We observe signals for the decays psi(3770)--> X J/psi from data acquired with the CLEO detector operating at the CESR e^+e^- collider with sqrt{s}=3773 MeV. We measure the following branching fractions B(psi(3770)--> XJ/psi) and significances: (189 +- 20 +- 20) x 10^-5 (11.6sigma) for X=pi^+pi^-, (80 +- 25 +- 16) x 10^-5 (3.4sigma) for X=pi^0pi^0, and (87 +- 33 +- 22) x 10^-5 (3.5sigma) for X=eta, where the errors are statistical and systematic, respectively. The radiative return process e^+e^- -->gamma psi(2S) populates the same event sample and is used to measure Gamma_{ee}[psi(2S)]=(2.54 +…
With 14 Million psi' events, many two-body decay channels are studied, which include Vector Pseudoscalar, Vector Tensor, Pseudoscalar Pseudoscalar channels. Based on systematical measurements for charmonium decay, 12% rule is tested, the phase between strong and electromagnetic amplitudes is studied. In addition, hadronic and radiative transitions of charmonia are measured to improve experimental accuracy and test theoretical calculations.
We study the processes e+e- -> (J/psi gamma gamma) gamma and e+e- -> (J/psi pi- pi+) gamma where the hard photon radiated from an initial e+e- collision with center-of-mass (CM) energy near 10.58 GeV is detected. In the final state J/psi gamma gamma we consider J/psi pi0, J/psi eta, chi_{c1} gamma, and chi_{c2} gamma candidates. The invariant mass of the hadronic final state defines the effective e+e- CM energy in each event, so these data can be compared with direct e+e- measurements. We report 90% CL upper limits for the integrated cross section times branching fractions of the J/psi gamma g…
In a study of B+ --> J/psi gamma K+ decays, we find evidence for the radiative decay X(3872) --> J/psi gamma with a statistical significance of 3.4 sigma. We measure the product of branching fractions BF(B+ --> X(3872) K+).BF(X(3872) --> J/psi gamma) = (3.3 +/- 1.0 +/- 0.3) x 10^-6, where the uncertainties are statistical and systematic, respectively. We also measure the branching fraction BF(B+ --> chi_c1 K+) = (4.9 +/- 0.2 +/- 0.4) x 10^-4. These results are obtained from (287+/-3) million BBar decays collected at the Y(4S) resonance with the BaBar detector at the PEP-II B Factory at SLAC.
We report the results of a search for $B^{-} \to \jpsi Λ\pbar$ based on a data set of 78 fb$^{-1}$ data collected at the $Υ(4S)$ resonance with the Belle detector at the KEKB asymmetric $e^+ e^-$ collider. No substantial signal is found, and we set the branching fraction upper limit ${\cal B}(B^{-} \to \jpsi Λ\pbar) < 4.1 \times 10^{-5}$ at 90% confidence level.
We report a measurement of the CP violation in B^0 -> J/ψK^0_S decays. We perform a time-dependent analysis of the decays reconstructed in 35/pb of LHCb data that was taken in 2010. We measure the CP asymmetry parameter
The BABAR Collaboration performed a search for xi(2220) production in the initial-state radiation process e^+e^- --> gamma J/psi, J/psi --> gamma K^+K^- or J/psi --> gamma K^0_SK^0_S. No evidence for the xi(2220) resonance has been found. The 90% confidence level upper limits on the product of branching fractions are sensitive to the spin and helicity hypotheses. These upper limits are of the order 10^-5, below the values reported in previous experiments. Also at BABAR, the decays B --> J/psi pi^+ pi^- pi^0 K are studied to search for the decay X(3872) --> J/psi omega. This search yields a fou…
We investigate the decay B^+ -> J/psi phi K^+ in a search for the X(4140) state, a narrow threshold resonance in the J/psi phi system. The data sample corresponds to an integrated luminosity of 10.4 fb^{-1} of ppbar collisions at sqrt s =1.96 TeV collected by the D0 experiment at the Fermilab Tevatron collider. We observe a mass peak with a statistical significance of 3.1 standard deviations and measure its invariant mass to be M=4159.0 +-.3 (stat) +- 6.6 (syst) MeV and its width to be Gamma= 19.9+-12.6 (stat)}^{+1.0}_{-8.0} (syst) MeV. Identifying this mass peak as the X(4140), we measure, fo…
We report the observation of the $B$ meson decay $B^\pm\to J/ψηK^\pm$ and evidence for the decay $B^0\to J/ψηK^0_S$, using {90} million $BBbar$ events collected at the $\ensuremath{Υ{(4S)}}\xspace$ resonance with the $BaBar$ detector at the PEP-II $e^+ e^-$ asymmetric-energy storage ring. We obtain branching fractions of $\cal{B}$$(B^\pm\to J/ψηK^{\pm}$)=$(10.8\pm 2.3(\rm{stat.})\pm 2.4(\rm{syst.}))\times 10^{-5}$ and $\cal{B}$$(B^0\to J/ψηK_{\rm{S}}^{0}$)=$(8.4\pm 2.6(\rm{stat.})\pm 2.7(\rm{syst.}))\times 10^{-5}$. We search for the new narrow mass state, the X(3872), recently reported by the…
In this talk, we present the recent results on charmonium decays from the BES experiment at the BEPC collider. The analyses are based on a 14 million psi(2S) events data sample. We report results on leptonic decays, hadronic decays, and radiative decays of psi(2S), as well as hadronic decays of chi_cJ states and rare or forbidden decays of J/psi.
We propose that the radiative decay process, η_b\to J/ψγ, may serve as a clean searching mode for η_b in hadron collision facilities. By a perturbative QCD calculation, we estimate the corresponding branching ratio to be of order 10^{-7}. Though very suppressed, this radiative decay channel in fact has larger branching ratio than the hadronic decay process η_b\to J/ψJ/ψ, which was previously hoped to be a viable mode for ferreting out η_b in Tevatron Run 2. The discovery potential of η_b through this channel seems promising in the forthcoming LHC experiments and maybe even in Tevatron Run 2, t…
We present the results of a search for the spin-singlet P-wave state hc(1 1P1) of charmonium formed through proton-antiproton annihilation at Fermilab experiment E835. The decay channels whjich were studied were ppbar -> J/psi + X -> e^+e^- + X, ppbar -> J/psi + pi0 -> e^+e^- + 2gamma, ppbar -> J/psi + pi0pi0 -> e^+e^- + 4gamma, and the neutral channel ppbar -> eta_c gamma -> (2gamma) gamma. The decay ppbar -> J/psi gamma -> e^+e^- gamma, into which 1P1 decay is forbidden by C-parity conservation, was also examined for comparison The 90% confidence upper limits for the decay channels studied i…
In this note we present a study of the radiative tails in the invariant mass spectra of muon or electron pairs from J/psi, psi(2S) and Upsilon(1S) decays which is due to an additional emission of a photon. An analytic formula for dilepton mass spectra in radiative decays is derived and a Monte Carlo simulation for realistic detector conditions is used to study effects on the spectra. A rather simple parameterisation is given, suitable for the treatment of real data.
Using the radiative return method, experiments at high luminosity electron-positron colliders allow to explore the kaon and the pion form factors in the time-like region up to fairly high energies. This opens the possibility to study kaon and pion pair production at and around the narrow resonances J/psi and psi(2S) and explore the interference between electromagnetic and hadronic amplitudes. Parameterizations of charged and neutral kaon as well as pion form factors are derived, which lead to an improved description of the data in the region of large invariant masses of the meson pair. These f…
With a sample of (225.2\pm2.8)*10^{6} J/psi events registered in the BESIII detector, J/psi->gamma pi^+ pi^- eta' is studied using two eta' decay modes: eta'->pi^+ pi^- eta and eta' -> gamma rho^0. The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20σ. In addition, in the pi^+pi^-eta' invariant mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2σand 6.4σ, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseu…
We report on an exclusive search for the X(3872) state in the decay pi+ pi- J/psi, J/psi to l+ l- (l = e, mu) from untagged gamma-gamma fusion and initial state radiation production using a 15.1 fb-1 data sample with the CLEO III detector. By taking advantage of the unique pi+ pi- J/psi decay kinematics, separate measurements for each production process are obtained. No signals are observed and preliminary upper limits have been established as [(2J+1)*Width_gamgam(X(3872))*BR(X(3872) to pi+ pi- J/psi)] < 12.9 eV and [Width_ee(X(3872))*BR(X(3872) to pi+ pi- J/psi)] < 8.0 eV, both at a 90% confi…
We present a study of the X(3940) state in the process e+e- -> J/psi D* Dbar. The X(3940) mass and width are measured to be (3942 +7 -6 +- 6)MeV/c^2 and Gamma=(37 + 26 - 15 +- 8 MeV. In the process e+e- -> J/psi D* D*bar we have observed another charmonium-like state, which we denote as X(4160), in the spectrum of invariant masses of D*+ D*- combinations. The X(4160) parameters are M= 4156 + 25 - 20 +- 15 MeV/c^2 and Gamma = 139 + 111 -61 +- 21 MeV. The analysis is based on a data sample with an integrated luminosity of 693 /fb recorded near the Upsilon(4S) resonance with the Belle detector at…
We present results of a search for the X(3872) in B0-->X(3872)KS0,X(3872)-->J/psi pi+ pi-, improved measurements of B-->X(3872)K-, and a study of the J/psi pi+ pi- mass region above the X(3872). We use 232x106 B[overline B] pairs collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II e+e- asymmetric-energy storage rings. The results include the 90% confidence interval 1.34x10-6<BR(B0-->X(3872)K0,X-->J/psi pi+ pi-)<10.3x10-6 and the branching fraction BR(B-->X(3872)K-,X-->J/psi pi+ pi-)=(10.1+-2.5+-1.0)x10-6. We observe a (2.7+-1.3+-0.2)MeV/c2 mass difference of the X(3872…
We report on a search for the recently reported X(3872) state using 15.1 fb^{-1} e+ e- data taken in the \sqrt{s} = 9.46-11.30 GeV region. Separate searches for the production of X(3872) in untagged gamma-gamma fusion and e+ e- annihilation following initial state radiation (ISR) are made by taking advantage of the unique correlation of J/psi -> l+ l- in X(3872) decay to pi+ pi- J/psi. No signals are observed in either case, and 90% confidence upper limits are established as (2J+1)Γ_{γγ}B(X -> pi+ pi- J/psi) < 12.9 eV and Γ_{ee}B(X -> pi+ pi- J/psi) < 8.3 eV.
A search for decays of the B_c meson was performed using data collected from 1990-1995 with the OPAL detector on or near the Z peak at LEP. The decay channels B_c^+ -> J/psi pi^+, B_c^+ -> J/psi a_1^+ and B_c^+ -> J/psi ell^+ nu were investigated, where ell denotes an electron or a muon. Two candidates are observed in the mode B_c^+ -> J/psi pi^+, with an estimated background of (0.63 +/- 0.20) events. The weighted mean of the masses of the two candidates is (6.32 +/- 0.06) GeV/c^2, which is consistent with the predicted mass of the B_c meson. One candidate event is observed in the mode B_c^+ …
We report on the search for a charged partner of the X(3872) in the decay $B \to X^\pm K$, $X^\pm \to J/ψπ^\pm π^0$, using 213 million $B\bar B$ events collected at the $Υ(4S)$ resonance with the BaBar detector at the PEP-II $e^+ e^-$ asymmetric-energy storage ring. The resulting product branching fraction upper limits are $BR (\bar{B}^0/B^0 \to X^\pm K^\mp$, $X^\pm \to J/ψπ^\pm π^0)$ $< 5.8 \times 10^{-6}$ and $BR (B^\pm \to X^\pm K^0_S$, $X^\pm \to J/ψπ^\pm π^0)$ $< 11 \times 10^{-6}$ at the 90% confidence level. All results are preliminary.
We report on a search for the X(3872) state using 15.1 fb^{-1} of e+ e- annihilation data taken with the CLEO III detector in the sqrt{s} = 9.46-11.30 GeV region. Separate searches for the production of X(3872) in untagged gamma gamma fusion and e+ e- annihilation following initial state radiation are made by taking advantage of the unique correlation of J/psi -> l+ l- in X(3872) decay into J/psi pi+ pi-. No signals are observed in either case, and 90% confidence upper limits are established as (2J+1)Gamma_{gammagamma}(X(3872))B(X -> J/psi pi+ pi-) < 12.9 eV and Gamma_{ee}(X(3872))B(X -> J/psi…
Non-$D\bar{D}$ decay $\psppto \rhopi$ is searched for using a data sample of $(17.3\pm 0.5) pb^{-1}$ taken at the center-of-mass energy of 3.773 GeV by the BESII detector at the BEPC. No $\rhopi$ signal is observed, and the upper limit of the cross section is measured to be $σ(\EETO \rhopi)<6.0 pb$ at 90% C. L. Considering the interference between the continuum amplitude and the $\pspp$ resonance amplitude, the branching fraction of $\pspp$ decays to $ρπ$ is determined to be $\BR(\pspp\raρπ)\in(6.0\times10^{-6}, 2.4\times10^{-3})$ at 90% C. L. This is in agreement with the prediction of the $S…
We search for the flavor-changing neutral-current decays B->K(*)nu nubar, and the invisible decays J/psi->nu nubar and psi(2S)->nu nubar via B->K(*)J/psi and B->K(*)psi(2S) respectively, using a data sample of 471 x10^6 BB pairs collected by the BaBar experiment. We fully reconstruct the hadronic decay of one of the B mesons in the Upsilon(4S)->BB decay, and search for the B->K(*)nu nubar decay in the rest of the event. We observe no significant excess of signal decays over background and report branching fraction upper limits of BR(B+->K+nu nubar)<3.7 x10^-5, BR(B0->K0nu nubar)< 8.1 x10^-5, B…
