209869059
Measurements of branching fractions, polarizations, and direct CP-violation asymmetries in $B \to \rho K^{*}$ and $B \to f_0(980) K^{*}$ decays
120186826
Physics at BES-III
This physics book provides detailed discussions on important topics in $\tau$-charm physics that will be explored during the next few years at \bes3 . Both theoretical and experimental issues are covered, including extensive reviews of recent theoretical developments and experimental techniques. Among the subjects covered are: innovations in Partial Wave Analysis (PWA), theoretical and experimental techniques for Dalitz-plot analyses, analysis tools to extract absolute branching fractions and measurements of decay constants, form factors, and CP-violation and \DzDzb-oscillation parameters. Programs of QCD studies and near-threshold tau-lepton physics measurements are also discussed.
120311240
Observation of $J/\psi \rightarrow p\bar{p}a_{0}(980)$ at BESIII
Using $2.25\times10^{8}$ $J/\psi$ events collected with the BESIII detector at the BEPCII storage rings, we observe for the first time the process $J/\psi\rightarrow p\bar{p}a_{0}(980)$, $a_{0}(980)\rightarrow \pi^{0}\eta$ with a significance of $6.5\sigma$ ($3.2\sigma$ including systematic uncertainties). The product branching fraction of $J/\psi\rightarrow p\bar{p}a_{0}(980)\rightarrow p\bar{p}\pi^{0}\eta$ is measured to be $(6.8\pm1.2\pm1.3)\times 10^{-5}$, where the first error is statistical and the second is systematic. This measurement provides information on the $a_{0}$ production near threshold coupling to $p\bar{p}$ and improves the understanding of the dynamics of $J/\psi$ decays to four body processes.
118501601
First observation of CP violation and improved measurement of the branching fraction and polarization of B0→D*+D*− decays
We report the measurement of the branching fraction, the polarization, and the parameters of the time-dependent CP violation in B-0 -> D*(+) D*(-) decays using a data sample of 772 x 10(6)B (B) over bar pairs, collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We obtain a branching fraction of B = (7.82 +/- 0.38 +/- 0.63) x 10(-4), a CP-odd fraction of R-perpendicular to = 0.138 +/- 0.024 +/- 0.006 and, additionally, a fraction of the longitudinal component in the transversity base of R-0 = 0.624 +/- 0.029 +/- 0.011. The measured values of the parameters of the CP violation are SD*+ D*- = 0.79 +/- 0.13 +/- 0.03 and A(D*+ D*-) 0.15 +/- 0.08 +/- 0.04.
21907946
Search for T, CP, and CPT violation in B0-B0 mixing with inclusive dilepton events.
We report the results of a search for T, CP, CPT, and violation in B0-B0 mixing using an inclusive dilepton sample collected by the BABAR experiment at the PEP-II factory. Using a sample of 232 x 10(6) BB pairs, we measure the T and CP violation parameter |q/p| - 1 = (-0.8 +/- 2.7(stat) +/- 1.9(syst) x 10(-3), and the CPT and CP parameters Imz = (13.9 +/- 7.3(stat) +/- 3.2(syst)) x 10(-3) and Delta Gamma x Rez = (7.1 +/- 3.9(stat) +/- 2.0(stat)) x 10(-3) ps(-1). The statistical correlation between the measurements of Imz and Delta Gamma x Rez is 76%.
124556172
Searches for charmless decays $B^0 \to \eta \omega$, $B^0 \to \eta K^0$, $B^{+} \to \eta \rho^{+}$, and $B^{+} \to \eta^\prime \pi^{+}$
119108965
Coulomb gauge model for hidden charm tetraquarks
Abstract The spectrum of tetraquark states with hidden charm is studied within an effective Coulomb gauge Hamiltonian approach. Of the four independent color schemes, two are investigated, the ( q c ¯ ) 1 ( c q ¯ ) 1 singlet–singlet (molecule) and the ( q c ) 3 ( q ¯ c ¯ ) 3 triplet–triplet (diquark), for selected J PC states using a variational method. The predicted masses of triplet–triplet tetraquarks are roughly a GeV heavier than the singlet–singlet states. There is also an interesting flavor dependence with ( q q ¯ ) 1 ( c c ¯ 1 ) states about half a GeV lighter than ( q c ¯ ) 1 ( q ¯ c ) 1 . The lightest 1 + + and 1 − − predictions are in agreement with the observed X ( 3872 ) and Y ( 4008 ) masses suggesting they are molecules with ω J / ψ and η h c , rather than D ⁎ D ¯ ⁎ and D D ¯ , type structure, respectively. Similarly, the lightest isovector 1 + + molecule, having a ρ J / ψ flavor composition, has mass near the recently observed charged Z c ( 3900 ) value. These flavor configurations are consistent with observed X , Y and Z c decays to π π J / ψ .
67782518
Primary proton flux around the "knee" region deduced from the observation of air showers accompanied by gamma families
The simultaneous observation of -families and accompanied air showers enables us to obtain the primary proton flux around the knee energy region where no direct measurements are available up to now. We operated a hy- brid experiment which consists of emulsion chambers and the Tibet-II air-shower array (AS) at Yangbajing (4,300 m a.s.l., 606 g/cm ) in 1996-1999. The total area of emulsion chamber (EC) and burst detector (BD) complex was 80 m and they were set up near the center of the Tibet-II air-shower array. We already published the primary proton flux in the energy region ranging from eV to eV using the BD and AS data. We used an artificial neural network to select the proton-induced events from the EC data set. The proton fluxes obtained from this experiment are presented in the knee energy region. Our result suggests that the primary becomes heavy dominant in the knee energy region.
6479982
Franck‐Condon principle for heavy‐quark hadron decays
The Franck‐Condon principle governing molecular electronic transitions is utilized to study heavy‐quark hadron decays. This provides a direct assessment of the wavefunction of the parent hadron if the momentum distribution of the open‐flavor decay products is measured. Model‐independent results include an experimental distinction between quarkonium and exotica (hybrids, tetraquarks…), an off‐plane correlator signature for tetraquarks and a direct probe of the sea quark orbital wavefunction relevant in the discussion of 3S1 or 3P0 decay mechanisms.
7419903
Chiral symmetry restoration in strange hadronic matter
The phase transition of chiral symmetry restoration in strange hadronic matter is studied in the chiral SU(3) quark mean field model. When the baryon density is larger than a critical density {rho}{sub c}, the minimal energy density of the system occurs at the point where the effective masses of nucleon, {lambda}, or {xi} drop to zero. The physical quantities change discontinuously at this density and the system will be in the phase of chiral symmetry restoration. A rich phase structure of strange hadronic matter with different strangeness fraction f{sub s} is obtained.
17090204
Strange nucleon form-factors in the perturbative chiral quark model
We apply the perturbative chiral quark model at one loop to calculate the strange form factors of the nucleon. A detailed numerical analysis of the strange magnetic moments and radii of the nucleon, and also the momentum dependence of the form factors is presented.