3,803 research outputs found

    Thermodynamic Geometry of black hole in the deformed Horava-Lifshitz gravity

    Full text link
    We investigate the thermodynamic geometry and phase transition of Kehagias-Sfetsos black hole in the deformed Horava-Lifshitz gravity with coupling constant λ=1\lambda=1. The phase transition in black hole thermodynamics is thought to be associated with the divergence of the capacities. And the structures of these divergent points are studied. We also find that the thermodynamic curvature produced by the Ruppeiner metric is positive definite for all r+>r−r_+ > r_- and is divergence at η2=0\eta_2=0 corresponded to the divergent points of CΦC_{\Phi} and CTC_T. These results suggest that the microstructure of the black hole has an effective repulsive interaction, which is very similar to the ideal gas of fermions. These may shine some light on the microstructure of the black hole.Comment: 5 pages, 3 figure

    Spectra of Free Diquark in the Bethe-Salpeter Approach

    Full text link
    In this work, we employ the Bethe-Salpeter (B-S) equation to investigate the spectra of free diquarks and their B-S wave functions. We find that the B-S approach can be consistently applied to study the diqaurks with two heavy quarks or one heavy and one light quarks, but for two light-quark systems, the results are not reliable. There are a few free parameters in the whole scenario which can only be fixed phenomenologically. Thus, to determine them, one has to study baryons which are composed of quarks and diquarks.Comment: 16 pages, no figure

    Search for D to phi l nu and measurement of the branching fraction for D to phi pi

    Full text link
    Using a data sample of integrated luminosity of about 33 pb−1^{-1} collected around 3.773 GeV with the BESII detector at the BEPC collider, the semileptonic decays D+→ϕe+νeD^+ \to \phi e ^+\nu_e, D+→ϕμ+νμD^+ \to \phi \mu^+\nu_\mu and the hadronic decay D+→ϕπ+D^+ \to \phi \pi^+ are studied. The upper limits of the branching fractions are set to be BF(D+→ϕe+νe)<BF(D^+ \to \phi e ^+\nu_e) < 2.01% and BF(D+→ϕμ+νμ)<BF(D^+ \to \phi \mu^+ \nu_\mu) < 2.04% at the 90% confidence level. The ratio of the branching fractions for D+→ϕπ+D^+ \to \phi \pi^+ relative to D+→K−π+π+D^+ \to K^-\pi^+\pi^+ is measured to be 0.057±0.011±0.0030.057 \pm 0.011 \pm 0.003. In addition, the branching fraction for D+→ϕπ+D^+ \to \phi \pi^+ is obtained to be (5.2±1.0±0.4)×10−3(5.2 \pm 1.0 \pm 0.4) \times 10^{-3}.Comment: 6 pages, 5 figures, to be published in Eur.Phys.J.

    Measurements of branching fractions for inclusive K0~/K0 and K*(892)+- decays of neutral and charged D mesons

    Get PDF
    Using the data sample of about 33 pb-1 collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we have studied inclusive K0~/K0 and K*(892)+- decays of D0 and D+ mesons. The branching fractions for the inclusive K0~/K0 and K*(892)- decays are measured to be BF(D0 to K0~/K0 X)=(47.6+-4.8+-3.0)%, BF(D+ to K0~/K0 X)=(60.5+-5.5+-3.3)%, BF(D0 to K*- X)=(15.3+- 8.3+- 1.9)% and BF(D+ to K*- X)=(5.7+- 5.2+- 0.7)%. The upper limits of the branching fractions for the inclusive K*(892)+ decays are set to be BF(D0 to K*+ X)<3.6% and BF(D+ to K*+ X) <20.3% at 90% confidence level

    Measurement of the cross section for e^+e^- -> ppbar at center-of-mass energies from 2.0 to 3.07 GeV

    Full text link
    Cross sections for e^+e^- -> ppbar have been measured at 10 center-of-mass energies from 2.0 to 3.07 GeV by the BESII experiment at the BEPC, and proton electromagnetic form factors in the time-like region have been determined.Comment: 6 pages, 3 figure

    Partial Wave Analysis of χc0→π+π−K+K−\chi_{c0}\to\pi^+\pi^-K^+K^-

    Full text link
    A partial wave analysis of χc0→π+π−K+K−\chi_{c0}\to\pi^+\pi^-K^+K^- in ψ(2S)→γχc0\psi(2S)\to\gamma\chi_{c0} decay is presented using a sample of 14 million ψ(2S)\psi(2S) events accumulated by the BES II detector. The data are fitted to the sum of relativistic covariant tensor amplitudes for intermediate resonant decay modes. From the fit, significant contributions to χc0\chi_{c0} decays from the channels f0(980)f0(980)f_0(980)f_0(980), f0(980)f0(2200)f_0(980)f_0(2200), f0(1370)f0(1710)f_0(1370)f_0(1710), K∗(892)0Kˉ∗(892)0K^*(892)^0\bar K^*(892)^0, K0∗(1430)Kˉ0∗(1430)K^*_0(1430)\bar K^*_0(1430), K0∗(1430)Kˉ2∗(1430)+c.c.K^*_0(1430)\bar K^*_2(1430) + c.c., and K1(1270)KK_1(1270)K are found. Flavor-SU(3)-violating K1(1270)−K1(1400)K_1(1270)-K_1(1400) asymmetry is observed. Values obtained for the masses and widths of the resonances f0(1710)f_0(1710), f0(2200)f_0(2200), f0(1370)f_0(1370), and K0∗(1430)K^*_0(1430) are presented.Comment: 16 pages, 9 figures, and 4 table

    Measurement of the chi_{c2} Polarization in psi(2S) to gamma chi_{c2}

    Full text link
    The polarization of the chi_{c2} produced in psi(2S) decays into gamma chi_{c2} is measured using a sample of 14*10^6 psi(2S) events collected by BESII at the BEPC. A fit to the chi_{c2} production and decay angular distributions in psi(2S) to gamma chi_{c2}, chi_{c2} to pi pi and KK yields values x=A_1/A_0=2.08+/-0.44 and y=A_2/A_0=3.03 +/-0.66, with a correlation rho=0.92 between them, where A_{0,1,2} are the chi_{c2} helicity amplitudes. The measurement agrees with a pure E1 transition, and M2 and E3 contributions do not differ significantly from zero.Comment: 6 pages, 4 figures, 1 tabl
    • …
    corecore