Search results for "Quarkonium"
showing 10 items of 92 documents
Evidence for the decayX(3872)→J/ψω
2010
We present a study of the decays B^(0,+)→J/ψπ^+π^-π^0K^(0,+), using 467×10^6 BB[overbar] pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872)→J/ψω, with product branching fractions B(B^+→X(3872)K^+)×B(X(3872)→J/ψω)=[0.6±0.2(stat)±0.1(syst)]×10^(-5), and B(B^0→X(3872)K^0)×B(X(3872)→J/ψω)=[0.6±0.3(stat)±0.1(syst)]×10^(-5). A detailed study of the π^+π^-π^0 mass distribution from X(3872) decay favors a negative-parity assignment.
Measurement of double charmonium production ine+e−annihilations ats=10.6 GeV
2005
We study $e^+e^-\to J/\psi c\bar{c}$ by measuring the invariant mass distribution recoiling against fully reconstructed $J/\psi$ decays, using 124 fb$^{-1}$ of data collected with a center-of-mass energy of 10.6 GeV with the $BaBar$ detector. We observe signals for $\eta_c(1S)$, $\chi_{c0}$, and $\eta_c(2S)$ in the recoil mass distribution, thus confirming previous measurements. We measure $\sigma(e^+e^-\to J/\psi+c\bar{c}) {\cal B} (c\bar{c} \to >2 charged)$ to be $17.6\pm2.8 (stat)^{+1.5}_{-2.1}(syst)$ fb, $ 10.3\pm2.5(stat)^{+1.4}_{-1.8}syst)$ fb, and $16.4\pm3.7(stat)^{+2.4}_{-3.0}(syst)$ fb with $c\bar{c}=\eta_c(1S)$, $\chi_{c0}$, and $\eta_c(2S)$, respectively.
Vector meson-vector meson interaction in a hidden gauge unitary approach
2008
The formalism developed recently to study vector meson-vector meson interaction, and applied to the case of rho rho, is extended to study the interaction of the nonet of vector mesons among themselves. The interaction leads to poles of the scattering matrix corresponding to bound states or resonances. We show that 11 states (either bound or resonant) get dynamically generated in nine strangeness-isospin-spin channels. Five of them can be identified with those reported in the PDG, i.e., the f(0)(1370), f(0)(1710), f(2)(1270), f(2)(')(1525), and K-2(*)(1430). The masses of the latter three tensor states have been used to fine-tune the free parameters of the unitary approach, i.e., the subtrac…
Spin-dependent potentials from lattice QCD
2006
The spin-dependent corrections to the static inter-quark potential are phenomenologically relevant to describing the fine and hyperfine spin splitting of the heavy quarkonium spectra. We investigate these corrections, which are represented as the field strength correlators on the quark-antiquark source, in SU(3) lattice gauge theory. We use the Polyakov loop correlation function as the quark-antiquark source, and by employing the multi-level algorithm, we obtain remarkably clean signals for these corrections up to intermediate distances of around 0.6 fm. Our observation suggests several new features of the corrections.
Randall-Sundrum corrections to the width difference andCP-violating phase inBs0-meson decays
2011
We study the impact of the Randall-Sundrum setup on the width difference $\ensuremath{\Delta}{\ensuremath{\Gamma}}_{s}$ and the $CP$-violating phase ${\ensuremath{\phi}}_{s}$ in the ${\overline{B}}_{s}^{0}$-${B}_{s}^{0}$ system. Our calculations are performed in the general framework of an effective theory, based on operator product expansion. The results can thus be used for many new-physics models. We find that the correction to the magnitude of the decay amplitude ${\ensuremath{\Gamma}}_{12}^{s}$ is below 4% for a realistic choice of input parameters. The main modification in the $\ensuremath{\Delta}{\ensuremath{\Gamma}}_{s}/{\ensuremath{\beta}}_{s}$-plane is caused by a new $CP$-violati…
Two-photon and one-photon–one-vector meson decay widths of thef0(1370),f2(1270),f0(1710),f2′(1525), andK2*(1430)
2010
We calculate the radiative decay widths, two-photon ($\ensuremath{\gamma}\ensuremath{\gamma}$) and one-photon--one-vector meson ($V\ensuremath{\gamma}$), of the dynamically generated resonances from vector-meson--vector-meson interaction in a unitary approach based on the hidden-gauge Lagrangians. In the present paper we consider the following dynamically generated resonances: ${f}_{0}(1370)$, ${f}_{0}(1710)$, ${f}_{2}(1270)$, ${f}_{2}^{\ensuremath{'}}(1525)$, ${K}_{2}^{*}(1430)$, two $\mathrm{\text{strangeness}}=0$ and $\mathrm{\text{isospin}}=1$ states, and two $\mathrm{\text{strangeness}}=1$ and $\mathrm{\text{isospin}}=1/2$ states. For the ${f}_{0}(1370)$ and ${f}_{2}(1270)$ we reproduc…
Quark model description of the tetraquark stateX(3872)in a relativistic constituent quark model with infrared confinement
2010
We explore the consequences of treating the $X(3872)$ meson as a tetraquark bound state. As dynamical framework we employ a relativistic constituent quark model which includes infrared confinement in an effective way. We calculate the decay widths of the observed channels $X\ensuremath{\rightarrow}J/\ensuremath{\psi}+2\ensuremath{\pi}(3\ensuremath{\pi})$ and $X\ensuremath{\rightarrow}{\overline{D}}^{0}+{D}^{0}+{\ensuremath{\pi}}^{0}$ via the intermediate off-shell states $X\ensuremath{\rightarrow}J/\ensuremath{\psi}+\ensuremath{\rho}(\ensuremath{\omega})$ and $X\ensuremath{\rightarrow}\overline{D}+{D}^{*}$. For reasonable values of the size parameter ${\ensuremath{\Lambda}}_{X}$ of the $X(3…
IMPLICATIONS OF A LARGE $Ht \bar{t}$-COUPLING FOR THREE-BODY DECAYS OF HIGGS BOSON AND TOP QUARK
1991
The three-body decays a heavy Higgs [Formula: see text], [Formula: see text] and of a heavy top t → bW+ H are studied in the context of the Standard Model. The common feature of these decay channels is the relative big coupling constant of the Higgs particle to the top quark. Indeed within a certain range of the masses M H , mt we find that branching ratios of the order O(10-3) are possible for the decays [Formula: see text] and t → bW+ H. The decay with [Formula: see text] as a function of M H and mt is investigated below the 2mt threshold (Mtt < 2mt) and is found to have an interesting behaviour just near this threshold.
Hyperons, Charm and Beauty Hadrons: Conclusion and Outlook
2001
In this concluding talk, the advances in the Flavour Problem studies are discussed, following the structure of the presentations in the Conference. The subjects touched are organized as follows: Baryons, K-physics, Charm and Beauty production, Charm and Beauty decays, B-Mixing and CP-Violation, Heavy Quarkonium.
Precision measurements ofB[ψ(3686)→π+π−J/ψ]andB[J/ψ→l+l−]
2013
Based on (106.41 +/- 0.86) x 10(6) psi(3686) events collected with the BESIII detector at the BEPCII collider, the branching fractions of psi(3686) -> pi(+)pi(-)J/psi, J/psi -> e(+)e(-), and J/psi -> mu(+)mu(-) are measured. We obtain B[psi(3686) -> pi(+)pi(-)J/psi] = (34.98 +/- 0.02 +/- 0.45)%, B[J/psi -> e(+)e(-)] = (5.983 +/- 0.007 +/- 0.037)%, and B[J/psi -> mu(+)mu(-)] = (5.973 +/- 0.0007 +/- 0.038)%. The measurement of B[psi(3686) -> pi(+)pi(-)J/psi] confirms the CLEO-c measurement, and is apparently larger than the others. The measured J/psi leptonic decay branching fractions agree with previous experiments within one standard deviation. These results lead to B[J/psi -> l(+)l(-)] = (…