53723212
Search for doubly charmed baryons and study of charmed strange baryons at Belle
We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We search for doubly charmed baryons Xi(+(+))(cc) with the Lambda(+)(c) K- pi(+)(pi(+) ) and. Xi(0)(c) pi(+)(pi(+)) final states. No significant signal is observed. We also search for two excited charmed strange baryons, Xi(c)(3055)(+) and Xi(c)(3123)(+) with the Sigma(++)(c)(2455)K- and Sigma(++)(c)(2520)K- final states. The Xi(c)(3055)(+) signal is observed with a significance of 6.6 standard deviations including systematic uncertainty, while no signature of the Xi(c)(3123)(+) is seen. We also study properties of the Xi(c)(2645)(+) and measure a width of 2.6 +/- 0.2(stat) +/- 0.4(syst) MeV/c(2), which is the first significant determination.
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%.
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.
124556172
Searches for charmless decays $B^0 \to \eta \omega$, $B^0 \to \eta K^0$, $B^{+} \to \eta \rho^{+}$, and $B^{+} \to \eta^\prime \pi^{+}$
84836167
Constraints on dark matter models from a Fermi LAT search for high-energy cosmic-ray electrons from the Sun
During its first year of data taking, the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope has collected a large sample of high-energy cosmic-ray electrons and positrons (CREs ...
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 .
120693974
Strange hadronic matter in a chiral SU(3) quark mean-field model
A quark-meson coupling model based on SU(3)(L) x SU(3)(R) symmetry and scale invariance is proposed, We apply this chiral SU(3) quark mean-field model to investigate strange hadronic matter including Lambda, Sigma and Xi hyperons, With the symmetry-breaking term, all the hyperon potentials are reasonable. The effective baryon masses, binding energy and hyperon ratios are discussed with four types of confining potentials. (C) 2001 Elsevier Science B.V. All rights reserved.
120920880
Strange hadronic matter in an effective model
Strange hadronic matter with nucleons, Λ-hyperon and Ξ-hyperon is studied using an effective model in the mean-field approximation. The density dependence of the effective baryon masses as well as the saturation properties and stabilities of the strange hadronic matter are discussed.
118975333
Strange hadronic matter in the FST model
The strange hadronic matter with nucleon, Λ-hyperon and Ⅺ-hyperon is studied by using the FST model in a mean-field approximation. The saturation properties and stabilities of the strange hadronic matter are discussed.