We report the results of a search for a charmonium-like state produced in the process gamma gamma --> omega J/psi in the 3.9-4.2 GeV/c^2 mass region. We observe a significant enhancement, which is well-described by a resonant shape with mass M = (3915 +/- 3 +/- 2) MeV/c^2 and total width Gamma = (17 +/- 10 +/- 3) MeV. This enhancement may be related to one or more of the three charmonium-like states so far reported in the 3.90-3.95 GeV/c^2 mass region.
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.
Results are presented on Charmonium using data collected with the CLEO III and CLEO-c detectors at the Psi(2S) and Psi(3770). Measurements include, the first observation of the hc(1P1) state, the electronic widths of the J/Psi and Psi(2S), the two photon width of the Chic2 and hadronic decays of the Psi(2S).
Using data collected with the CLEO detector operating at the CESR e+e- collider at sqrt s = 3.97-4.26 GeV, we investigate 15 charmonium decay modes of the psi(4040), psi(4160), and Y(4260) resonances. We confirm, at 11$σ$ significance, the BaBar Y(4260) --> pi+ pi- J/psi discovery, make the first observation of Y(4260) --> pi0 pi0 J/psi (5.1 sigma), and find the first evidence for Y(4260) --> K+ K- J/psi (3.7 sigma). We measure e+e- cross-sections at sqrt s = 4.26 GeV as sigma(pi+ pi- J/psi) = 58 +12-10 +- 4 pb, sigma(pi0 pi0 J/psi) = 23 +12 -8 +- 1 pb, and sigma(K+ K- J/psi) = 9 +9 -5 +- 1 pb…
We present a new analysis of double charmonium production in e^+ e^- annihilation. The observation of the processes e^+ e^- -> J/psi eta_c, J/psi chi_c0, and J/psi eta_c(2S) is confirmed using a dataset more than three times larger than that of Belle's previous report, and no evidence for the process e^+ e^- -> J/psi J/psi is found. We perform an angular analysis for J/psi eta_c production and set an upper limit on the production of J/psi J/psi. Processes of the type e^+ e^- -> psi(2S) (cc)_res have been observed for the first time; their rates are found to be comparable to those of e^+ e^- ->…
We report the observation of a near-threshold enhancement in the omega-J/psi invariant mass distribution for exclusive B-->K omega J/psi decays. The results are obtained from a 253 fb-1 data sample that contains 275 million BB-bar meson pairs that were collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e- collider. The statistical significance of the omega-J/psi mass enhancement is estimated to be greater than 8 sigma.
Recent results on charmonia decays at BES/BEPC are reported, including the observation of psi'-->K_S K_L, psi'--> Vector + Tensor for the measurement of the relative phase between the strong and electromagnetic decays of psi' and a test of the pQCD ``12% rule'' between psi' and J/psi decays; the study of psi'--> gamma gamma J/psi for the determination of psi'--> pi^0 J/psi, eta J/psi, gamma chi_c1 and gamma chi_c2 decay branching fractions; the test of the color-octet mechanism via chi_cJ--> p \bar{p} and chi_cJ--> Λ\barΛ; and a search for the CP violating process psi' and J/psi--> K_S K_S.
Based on 14 million psi(2S) and 58 million J/psi events collected by the BESII detector, the leptonic decay of psi(2S) into $τ^+τ^-$, psi(2S) multi-body decays, chi_cJ decays, and J/psi hadronic decays are studied, and the branching fractions of these decays are reported. These results may shed light on the understanding of QCD.
Since the discovery of the X(3872) in 2003 the B-factory experiments BaBar and Belle have been driving forces in the spectroscopy of new charmonium-like states. In this article the latest results on the decays X(3872) -> D0 D*0bar and X(3872) -> psi gamma, where psi stands for J/psi or psi(2S), are presented and analyses of Z(4430)+ -> psi pi+ and Z(4050/4250)+ -> chi_c1 pi+ are discussed.
A sample of 3.79 million psi(2S) decays observed in the BES detector is used to study the decays of charmonium to axialvector plus pseudoscalar mesons. The branching fraction for psi(2S) to b1pi agrees with expectations. A contrasting behavior between the psi(2S) and the J/psi decays to K1K cannot be accommodated by an adjustment of the singlet-triplet axialvector mixing angle.
We report the observation of a narrow charmonium-like state produced in the exclusive decay process B+ -> K+ pi+pi- J/psi. This state, which decays into pi+pi- J/psi, has a mass of 3872.0+-0.6(stat)+-0.5(syst) MeV, a value that is very near the M_D + M_D* mass threshold. The results are based on an analysis of 152M B-Bbar events collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider. The statistical significance of the signal is in excess of 10 sigma.
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.
The decay channel J/ψ->gamma omega omega, omega -> pi+ pi- pi0 is analyzed using a sample of 5.8x10^7 J/psi events collected with the BESII detector. The omega omega invariant mass distribution peaks at 1.76 GeV/c^2, just above the omega omega threshold. Analysis of angular correlations indicate that the omega omega system below 2 GeV/c^2 is predominantly pseudoscalar. A partial wave analysis confirms the predominant pseudoscalar structure, together with small 0^{++} and 2^{++} contributions, and yields a pseudoscalar mass M = 1744 \pm 10 (stat) \pm 15 (syst) MeV/c^2, a width Gamma = 244^{+24}…
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…
We report the first observation of a narrow charmmonium state produced in the exclusive decay process B+->K+ pi+pi- J/psi. This state, which decays into pi+pi-J/psi, has a mass of 3871.8+-0.7(stat)+-0.4(syst) MeV, which is very near the M_D + M_D* mass threshold. The results are based on an analysis of 152M BBbar events collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider.
We present a study of the decays $B^{0,+}\to J/ψωK^{0,+}$ using $383\times 10^{6}$ $B\bar{B}$ events obtained with the \babar detector at PEP-II. We observe $Y(3940) \to J/ψω$, with mass $3914.6 ^{+3.8}_{-3.4} (stat) \pm{2.0} (syst)$ \mevcc, and width $34^{+12}_{-8}(stat)\pm{5}(syst)$ \mev. The ratio of $B^0$ and $B^+$ decay to $YK$ is $0.27^{+0.28}_{-0.23}(stat)^{+0.04}_{-0.01}(syst)$, and the relevant $B^0$ and $B^+$ branching fractions are reported.
We report on exclusive decays of B mesons into final states containing charmonium using data collected with the BABAR detector at the PEP-II storage rings. The charmonium states considered here are J/psi, psi(2S), and chi_C1. Branching fractions for several exclusive final states, a measurement of the decay amplitudes for the B0 --> J/psi K* decay, and measurements of the B0 and B+ masses are presented. All of the results we present here are preliminary.
Using data acquired with the CLEO-c detector at the CESR e+e- collider, we measure branching fractions for J/psi, psi(2S), and psi(3770) decays to gamma pi0, gamma eta, and gamma eta'. Defining R_n = B[ psi(nS)-->gamma eta ]/B[ psi(nS)-->gamma eta' ], we obtain R_1 = (21.1 +- 0.9)% and, unexpectedly, an order of magnitude smaller limit, R_2 < 1.8% at 90% C.L. We also use J/psi-->gamma eta' events to determine branching fractions of improved precision for the five most copious eta' decay modes.
Using substantially larger data samples collected by the CLEO III detector, we report on new measurements of the decays of Upsilon(1S) to charmonium final states, including J/Psi, psi(2S), and chi_cJ. The latter two are first observations of these decays. We measure the branching fractions as follows: B(Y(1S)--> J/Psi+X)=(6.4+-0.4+-0.6)x10^-4, B(Y(1S)--> psi(2S)+X)/B(Y(1S)--> J/Psi+X)=0.41+-0.11+-0.08, B(Y(1S)--> chi_c1+X)/B(Y(1S)--> J/Psi+X)=0.35+-0.08+-0.06, B(Y(1S)--> chi_c2+X)/B(Y(1S)--> J/Psi+X)=0.52+-0.12+-0.09, and B(Y(1S)--> chi_c0+X)/B(Y(1S)--> J/Psi+X)<7.4% at 90% confidence level. W…
Recent results obtained from the BES psi(2S) data are summarized, including the measurement of the branching ratio of the J/psi to leptons, B(J/psi -> l^+ l^-) = 5.87 +/- 0.04 +/- 0.09, many psi(2S) and chi_c branching ratios, information on the rho-pi puzzle, and measurements of the mass of the chi_c0, m(chi_c0) = 3414.1 +/- 0.6 +/- 0.8 MeV, and the eta_c, m(eta_c) = 2975.8 +/- 3.9 +/- 1.2 MeV.
This paper summarizes recent results obtained from the BES psi(2S) data, which with 3.8 M events, is the world's largest data set. Distributions for psi(2S) -> pi^+ pi^- J/psi are fit to the Novikov-Shifman model. Preliminary branching fractions are reported for psi(2S) -> gamma f_2(1270) and gamma f_J(1710), as well as for decays into states containing an omega or phi. Finally recent measurements of the mass of the chi_c0 and eta_c are reported.
We reconstruct the charmonium mesons J/psi, psi(2S) and chi_C1 using a sample of 8.46 x 10^6 B-anti-B events collected by the BABAR detector operating at e^+e^- center of mass energies near the Y(4S) resonance. By measuring rates relative to the branching fraction of the J/psi, we obtain preliminary inclusive B branching fractions of (0.25+/-0.02+/-0.02)% to the psi(2S) and (0.39+/-0.04+/-0.04)% to the chi_C1, and set a 90% confidence level limit of 0.24% on decays through the chi_C2.
We present a study of the decays B^{0,+} --> J/psi pi^+ pi^- pi^0 K^{0,+}, using 467 10^6 BBbar pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) --> J/psi omega, with product branching fractions B(B^+ --> X(3872)K^+) B(X(3872) --> J/psi omega) =[0.6\pm0.2\stat \pm 0.1\syst ] 10^{-5}, and B(B^0 --> X(3872)K^0) B(X(3872) --> J/psi omega) =[0.6\pm0.3\stat \pm 0.1\syst ] 10^{-5}. A detailed study of the pi^+ pi^- pi^0 mass distribution from X(3872) decay favors a negative-parity assignment.
We report the latest outcomes for the Charmonium system investigation on 226x10^6 J/Psi and 106x10^6 Psi' events collected with the BESIII detector at the BEPCII e+e- collider.
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 report a new analysis of double charmonium production in e+ e- annihilation using a data sample collected by the Belle experiment. We confirm our previous observation of the processes e+ e- -> J/psi eta_c (chi_c0, eta_c(2S)) and perform an angular analysis for these processes. Processes of the type e+ e- -> psi(2S) (c cbar)_resonant are observed for the first time. We also observe a new charmonium state - X(3940), produced in the process e+ e- -> J/psi X(3940).
The phase variation of the sigma -> pi-pi amplitude is accurately determined as a function of mass from BES II data for J/Psi -> omega-pi-pi. The determination arises from interference with the strong b1(1235)-pi amplitude. The observed phase variation agrees within errors with that in pi-pi elastic scattering.
We report measurements of branching fractions for psi(2S) decays into omega pi pi, b1 pi,omega f2(1270),omega KK, omega p pbar, phi pi pi, phi f0(980),phi KK, and an upper limit for phi p pbar final states based on a data sample of 4 X 10^6 psi(2S) events collected with the BESI detector at the Beijing Electron-Positron Collider. The branching fractions for b1 pi and omega f2(1270) update previous BES results, while those for other decay modes are first measurements. The ratios of psi(2S)and J/psi branching fractions are smaller than what is expected from the 12% rule by a factor of five for o…
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…
Using 8.5M B-anti-B events recorded by the BABAR detector the yield of inclusive J/psi, the branching ratios of psi(2S) and chi_C1 are presented. Combining the charmonium state with either a K+,KS, K*+ or K*0 exclusive B decays are reconstructed and their branching ratios determined. Using the fully reconstructed decays, both the B0 and B+ masses and their difference is measured. Finally the contributions of CP even and odd amplitudes in the decay B to J/psi K* are determined from an angular analysis.
We report evidence for the decay modes X(3872) --> gamma J/psi and X(3872)--> pi+pi-pi0 J/psip. In the latter, the pi+pi-pi0 invariant mass distribution has a strong peak between 750 MeV and the kinematic limit of 775 MeV, suggesting that the process is dominated by the sub-threshold decay X --> omega J/psi. These results establish the charge-conjugation parity of the X(3872) as C=+1. The results are based on a study of X(3872) mesons produced via exclusive B --> K X(3872) decays in a 256 fb-1 data sample collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider. The X(…
Using a sample of >10^5 J/psi to mu+mu- decays, Fermilab experiment 789 has studied production of J/psi and psi-prime in 800-GeV proton-nucleon collisions. Differential cross sections and nuclear dependences have been measured for charmonium as well as for charm and beauty production. While charm and beauty production are consistent with perturbative QCD calculations, charmonium cross sections exceed the predictions of the color-singlet model by large factors, suggesting that additional mechanisms (such as color-octet production) may play important roles. Nuclear dependences of production cros…
We report measurements of charmonium resonances (J/Psi, Psi(2S),Chi_c1) using about 25 fb^-1 of data collected by the BABAR detector around the Upsilon(4S) resonance. We present measurements of inclusive charmonium production of charmonium in B decays and from the continuum, as well as exclusive branching ratios of B mesons into charmonium final states. We present also a measurement of the B0 -> K*0 gamma branching ratio and a search for the decay B0 -> gamma gamma.
The cross sections for e+e- to pi+pi-J/psi, pi+pi-psi(2S), K+K-J/psi, DDbar, DDbar pi, D*Dbar, and D*D*bar are measured using data sample collected on or near the Upsilon(4S) resonance with the Belle detector at KEKB. A peak near 4.25 GeV/c^2, corresponding to the so called Y(4260), is observed in pi+pi-J/psi final state. In addition, there is another cluster of events at around 4.05 GeV/c^2. Two resonant structures are observed in the pi+pi-psi(2S) invariant mass distribution, one at 4361+-9+-9 MeV/c^2 with a width of 74+-15+-10 MeV/c^2, and another at 4664+-11+-5 MeV/c^2 with a width of 48+-…
Measurements of inelastic production of charmonium with the ZEUS detector at HERA are presented. J/ψand psi' mesons have been identified using the decay channel psi -> mu+ mu-.The data, corresponding to an integrated luminosity of 38 pb-1 in photoproduction and 73.3 pb-1 in electroproduction, are confronted to theoretical predictions.
We report branching fractions and charge asymmetries for exclusive decays of charged and neutral B mesons to two-body final states containing a charmonium meson, J/psi or psi(2S). This result is based on a 29.4 fb^{-1} data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider.
The ALICE Collaboration studies the production of J/psi meson in pp collisions at the center-of-mass energies of 2.76 and 7 TeV at mid- and forward-rapidity. Inclusive production cross-sections are presented as a function of the collision energy, rapidity and transverse-momentum. The J/psi polarization measurements in the helicity and Collins-Soper frames are discussed. A novel result on the correlation between the collision charged particle multiplicity and J/psi yield is also shown.
Using 22.7 million BBbar events recorded with the BABAR detector, the inclusive branching fractions for the production of J/psi, psi(2S) and Chi_c in B decays are presented. Combining the charmonium state with a K+-, K0, K*+-, K*0 or neutral pion, B decays are reconstructed exlusively and branching fractions are determined. A preliminary study is also presented fot the B --> eta_c K decay mode.
Measurements of branching fractions for nine different final states, based on a data sample of approximately 4 million psi(2S) events collected with the BESI detector at the BEPC, are reported. Using the same event sample, radiative decays of the psi (2S) into pi pi, K K-bar and eta eta final states have been measured. Cross sections for e e -> e e, hadrons, pi pi J/psi, and mu mu have been measured in the vicinity of the psi(2S) resonance using the BESII detector. The psi(2S) total width; partial widths to hadrons, pi pi J/psi and muons; and corresponding branching fractions have been determi…
The resonance parameters of the excited psi-family resonances, namely the psi(4040), psi(4160), and psi(4415), were determined by fitting the R-values measured by experiments. It is found that the previously reported leptonic partial widths of these states were merely one possible solutions among a four-fold ambiguity. By fitting the most precise experimental data on the R-values measured by the BES collaboration, this work presents all four sets of solutions. These results may affect the interpretation of the charmonium and charmonium-like states above 4GeV/c^2.
The detection efficiency correction for the particle identification and kinematic fit selection criteria is investigated for the branching fraciton measurements in the psi(2S) decays into omega pi pi, b1 pi, omega f2(1270), omega K K, omega p pbar, phi pi pi, phi f0(980), phi K K and phi p pbar final states using 4 millions psi(2S) data sample coolected at BEPC/BES. Based on the corrected efficiencies, the preliminary results of these decay channels have been obtained, and the "12%" rule predicted by perturbative QCD theory tested.
e+e- Experiments producing charmonium are reviewed. It is found that the contribution of the continuum amplitude via virtual photon was neglected in almost all the experiments and the channels analyzed. It is shown that the contribution of the continuum part may affect the final results significantly in psi(2S) and psi(3770) decays, while the interference between continuum and resonance amplitudes may even affect the J/psi decays as well as the psi(2S) and psi(3770). This should be considered in analyzing the "rho-pi puzzle" between J/psi and psi(2s) decays, and the difference between inclusiv…
We report preliminary results on the measurement of branching fractions of exclusive decays of neutral and charged B mesons into two-body final states containing a charmonium state and a light strange meson. The charmonium mesons considered are J/psi, psi(2S) and chic_c1, and the light mesons are either K or K*. We use a sample of about 124 million BBbar events collected with the BABAR detector at the PEP-II storage ring at the Stanford Linear Accelerator Center.
We present a study of three B0 decay modes useful for time-dependent CP asymmetry measurements. From a sample of 9.7 million B meson pairs collected with the CLEO detector, we have reconstructed B0 -> J/psi K0S, B0 -> chi_c1 K0S, and B0 -> J/psi pi0 decays. The latter two decay modes have been observed for the first time. We describe a K0S -> pi0 pi0 detection technique and its application to the reconstruction of the decay B0 -> J/psi K0S. Combining the results obtained using K0S -> pi+ pi- and K0S -> pi0 pi0 decays, we determine Br(B0 -> J/psi K0) = (9.5 +- 0.8 +- 0.6)*10^-4, where the first…
We report measurements of branching fractions and charge asymmetries of exclusive decays of neutral and charged B mesons into two-body final states containing a charmonium state and a light strange meson. The charmonium mesons considered are J/Psi, Psi(2S) and Chi_c1, and the light meson is either K or K*. We use a sample of about 124 million BBbar events collected with the BABAR detector at the PEP-II storage ring at the Stanford Linear Accelerator Center.
We report the observation of the bottom, doubly-strange baryon Omega^-_b through the decay chain Omega^-_b -> J/psi Omega^-, where J/psi -> mu^+ mu^-, Omega^- -> Lambda K^-, and Lambda -> p pi^-, using 4.2 fb^{-1} of data from p\bar p collisions at sqrt{s}=1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 * 10^{-8}, or 5.5 Gaussian standard deviations. The Omega^-_b mass is measured to be 6054.4 +/- 6.8 (stat.) +/- 0.9 (syst.) MeV/c^2. The lifetime of the Omega^-_b baryon is measured to be 1.13^…
The branching ratios of psi(2S)-->p pbar Pi+ pi- and psi(2S)-->p pbar omega, omega--> pi+ pi- pi0 are measured and the pi+ pi- invariant mass distribution in the first decay is discussed by analyzing 14 million produced psi(2S) events collected by the BESII detector at the BEPC.
We present properties of weakly decaying bottom baryons, Xi_b and Omega_b, using 4.2 fb^-1 of data from p-pbar collisions at sqrt{s}=1.96 TeV, and recorded with the Collider Detector at Fermilab. We report the observation of the Omega_b through the decay chain Omega_b -> J/psi Omega^-, where J/psi -> mu^+ mu^-, Omega^- -> Lambda K^-, and Lambda -> p pi^-. Significance of the observed signal is estimated to be 5.5 Gaussian standard deviations. The Omega_b mass and lifetime are measured to be 6054.4 +- 6.8 (stat.) +- 0.9 (syst.) MeV/c^2 and 1.13^{+0.53}_{-0.40}(stat.) +- 0.02(syst.) ps, respecti…
Using a data sample of 24.5 million psi(2S) the reactions psi(2S)->gamma chi_cJ, chi_cJ->gamma gamma have been studied for the first time to determine the two-photon widths of the chi_cJ states of charmonium in their decay into two photons. The measured quantities are B(psi(2S)->gamma chi_c0)xB(chi_c0->gamma gamma)=(2.22+-0.32+-0.10)x10^-5, and B(psi(2S)->gamma chi_c2)xB(chi_c2->gamma gamma)=(2.70+-0.28+-0.15)x10^-5. Using values for B(psi(2S)->gamma chi_c0,c2) and Γ(chi_c0,c2) from the literature the two-photon widths are derived to be Γ_{gamma gamma}(chi_c0)=(2.53+-0.37+-0.26) keV, Γ_{gamma …
We report branching fraction measurements for exclusive decays of charged and neutral B mesons into two-body final states containing a charmonium meson. We use a sample of 22.72 +/- 0.36 million B anti-B events collected between October 1999 and October 2000 with the BABAR detector at the PEP-II storage rings at the Stanford Linear Accelerator Center. The charmonium mesons considered here are J/psi, psi(2S), and chi_c1, and the light meson in the decay is either a K, K^*, or pi^0.
Recent results from the CLEO experiment on decays and partial widths of various bottomonium and charmonium resonances are presented. New measurements of the di-electron partial widths for the 3 bound-state Upsilons and the J/psi are discussed. A determination of the total hadronic cross section for the psi(3770) is made, which solves a 20-year-old puzzle. The Y(4260) state is confirmed and its decay into 2 new modes is measured.
Results are reported based on samples of 58 million $\jpsi$ and 14 million $\psip$ decays obtained by the BESII experiment. Improved branching fraction measurements are determined, including branching fractions for $\jpsi\to\ppp$, $\psip\ra π^0\J$, $η\J$, $π^0 π^0 J/ψ$, anything $J/ψ$, and $ψ(2S)\arγχ_{c1},γχ_{c2}\arγγ\jpsi$. The decay $J/ψ\to ωπ^+π^-$ is studied. At low $ππ$ mass, a large, broad peak due to the $σ$ is observed, and its pole position is determined. Results are presented on $ψ(2S)$ and $J/ψ$ hadronic decays to $K^0_SpK^-\bar n$ and $K^0_S\bar p K^+n$ final states. No significan…
We have observed the reactions p+pbar --> p+X+pbar, with X being a centrally produced J/psi, psi(2S) or chi_c0, and gamma+gamma --> mu+mu-, in proton- antiproton collisions at sqrt{s} = 1.96 TeV using the Run II Collider Detector at Fermilab. The event signature requires two oppositely charged muons, each with pseudorapidity |eta| < 0.6, with M(mumu) in [3.0,4.0] GeV/c2, and either no other particles, or one additional photon, detected. The J/psi and the psi(2S) are prominent, on a continuum consistent with the QED process gamma+gamma --> mu+mu-. Events with a J/psi and an associated photon ca…
The electroproduction of J/psi and psi(2S) mesons is studied in elastic, quasi-elastic and inclusive reactions for four momentum transfers 2 < Q^2 < 80 GeV^2 and photon-proton centre of mass energies 25 < W < 180 GeV. The data were taken with the H1 detector at the electron proton collider HERA in the years 1995 to 1997. The total virtual photon-proton cross section for elastic J/psi production is measured as a function of Q^2 and W. The dependence of the production rates on the square of the momentum transfer from the proton (t) is extracted. Decay angular distributions are analysed and the r…
We re-analyse the two- and three-pion mass distributions in the decays X(3872)->rho J/psi and X(3872)->omega J/psi and argue that the present data favour the 1++ assignment for the quantum numbers of the X.
In this paper the studies of three different B decays to hadronic states are presented. These results are based on 1999-2003 dataset collected by the BaBar experiment at the PEP-II e+e- storage ring at the Stanford Linear Accelerator Center. The measurements are the hadronic branching fraction of B+ -> J/psi p Lambda-bar, B0 -> J/psi p p-bar, B0 -> D*+D-, and the direct CP-asymmetry in B0 -> D0(CP) K- channels.
Using information on B-meson fragmentation functions from CERN LEP 1 and adopting the nonrelativistic QCD factorization formalism proposed by Bodwin, Braaten, and Lepage, we predict the transverse-momentum distribution of J/psi mesons originating from the inclusive decays of b hadrons produced in p p-bar collisions at the Fermilab Tevatron. We determine the relevant colour-octet charmonium matrix elements from fits to CDF data on prompt charmonium hadroproduction and to CLEO data on charmonium production from B-meson decay. Our predictions are found to agree well with recent CDF and D0 data.
Using the QCD sum rules we test if the charmonium-like structure Y(4274), observed in the $J/ψϕ$ invariant mass spectrum, can be described with a $D_s\bar{D}_{s0}(2317)+h.c.$ molecular current with $J^{PC}=0^{-+}$. We consider the contributions of condensates up to dimension ten and we work at leading order in $α_s$. We keep terms which are linear in the strange quark mass $m_s$. The mass obtained for such state is $m_{D_s{D}_{s0}}=(4.80\pm 0.55)$ GeV. We also consider a molecular $0^{-+}$ $D\bar{D}_{0}(2400)+h.c.$ current and we obtain $m_{D{D}_0}=(4.61\pm 0.71)$ GeV. Our study shows that the…
A precision measurement of the mass of the h_c(1P1) state of charmonium has been made using a sample of 24.5 million psi(2S) events produced in e+e- annihilation at CESR. The reaction used was psi(2S) -> pi0 h_c, pi0 -> gamma gamma, h_c -> gamma eta_c, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which eta_c decays are reconstructed in fifteen hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of the present measurements are M(h_c)=3525.2…
A search for centrally produced charmonium states has been presented. There is no significant evidence for any charmonium production. An upper limit of 2 nb is found for the cross section of chic production using the decay chic(1P)-> J/psi gamma.
We present new precision measurements of the psi(2S) total and partial widths from excitation curves obtained in antiproton-proton annihilations by Fermilab experiment E835 at the Antiproton Accumulator in the year 2000. A new technique of complementary scans was developed to study narrow resonances with stochastically cooled antiproton beams. The technique relies on precise revolution-frequency and orbit-length measurements, while making the analysis of the excitation curve almost independent of machine lattice parameters. We study the psi(2S) meson through the processes pbar p -> e+ e- and p…
