Sharp constants in weighted trace inequalities on Riemannian manifolds

We establish some sharp weighted trace inequalities W^{1,2}(\rho^{1-2\sigma}, M)\hookrightarrow L^{\frac{2n}{n-2\sigma}}(\pa M) on $n+1$ dimensional compact smooth manifolds with smooth boundaries, where $\rho$ is a defining function of $M$ and $\sigma\in (0,1)$. This is stimulated by some recent work on fractional (conformal) Laplacians and related problems in conformal geometry, and also motivated by a conjecture of Aubin.Comment: 34 page

Elastic scattering and breakup reactions of the proton drip-line nucleus 8 B on 208 Pb at 238 MeV

Elastic scattering and breakup angular distributions of the weakly bound radioactive nucleus 8 B on a 208Pb target at an incident energy of 238 MeV, which corresponds to four times the Coulomb barrier, have been measured at the HIRFL-RIBLL facility (Institute of Modern Physics, Lanzhou). The data have been analyzed using the optical model and the continuum discretized coupled channels (CDCC) formalism. The measured and calculated elastic scattering angular distributions do not show any significant Coulomb rainbow suppression. The angular distribution for the breakup reaction was measured for the first time at this energy. The angular distribution of the 7 Be fragments could be reproduced considering elastic plus nonelastic breakup contributions, with the former evaluated with the CDCC calculations and the latter with the model of Ichimura, Austern, and Vincent [Phys. Rev. C 32, 431 (1985)]. The comparison of the breakup cross section of 8 B with that of 11Be suggests that the Coulomb and centrifugal barriers encountered by the valence proton may suppress the breakup cross section.Fundación Nacional Programa clave de I + D de China (Subvención No. 2018YFA0404403)Fundación Nacional de Ciencias Naturales de China (Subvenciones No. 11947203, No. 11775013, No. 11575256 y No. U1632138)Youth Innovation Promotion Association CAS de China (No. 2020411)Fundación de Investigación de São Paulo (FAPESP) (Becas No. 2016/17612-7 y No. 2018/04965-4)Ministerio español de Ciencia, Innovación y Universidades (incluyendo FEDER fondos) bajo el proyecto FIS2017-88410-PUnión Europea programa de investigación e innovación Horizonte 2020 de la Unión Acuerdo de Subvención No. 654002

Scattering of the halo nucleus 11Be from a lead target at 3.5 times the Coulomb barrier energy

Angular distributions of quasielastic scattering and breakup of the neutron-rich halo nucleus 11Be on a 208Pb target at an incident energy of 140 MeV (about 3.5 times the Coulomb barrier) were measured at HIRFL-RIBLL. A strong suppression of the Coulomb nuclear interference peak is observed in the measured quasielastic scattering angular distribution. The result demonstrates for the first time the persistence of the strong breakup coupling effect reported so far for reaction systems involving neutron-halo nuclei at this relatively high incident energy. The measured quasielastic scattering cross sections are satisfactorily reproduced by continuum discretized coupled channel (CDCC) calculations as well as by the XCDCC calculations where the deformation of the 10Be core is taken into account. The angular and energy distributions of the 10Be fragments could also be well reproduced considering elastic breakup (CDCC and XCDCC) plus nonelastic breakup contributions, with the latter evaluated with the model by Ichimura, Austern and Vincent [1]. The comparison of the 10Be energy distributions with simple kinematical estimates evidence the presence of a significant post-acceleration effect which, in the (X)CDCC frameworks, is accounted for by continuum-continuum couplings.National Key Research and Development Program of China (Grant No. 2018YFA0404403)National Natural Science Foundation of China (Grant No. 11775013, No. 11947203, No. 11575256, and No. U1632138)Youth Innovation Promotion Association CAS (No. 2020411)Ministerio de Ciencia, Innovación y Universidades FIS2017-88410-PEuropean Union’s Horizon 2020 (Grant Agreement No. 654002

Partial Wave Analysis of J/ψ→γ(K+K−π+π−)J/\psi \to \gamma (K^+K^-\pi^+\pi^-)

BES data on $J/\psi \to \gamma (K^+K^-\pi^+\pi^-)$ are presented. The $K^*\bar K^*$ contribution peaks strongly near threshold. It is fitted with a broad $0^{-+}$ resonance with mass $M = 1800 \pm 100$ MeV, width $\Gamma = 500 \pm 200$ MeV. A broad $2^{++}$ resonance peaking at 2020 MeV is also required with width $\sim 500$ MeV. There is further evidence for a $2^{-+}$ component peaking at 2.55 GeV. The non-$K^*\bar K^*$ contribution is close to phase space; it peaks at 2.6 GeV and is very different from $K^{*}\bar{K^{*}}$.Comment: 15 pages, 6 figures, 1 table, Submitted to PL

Measurements of J/psi Decays into 2(pi+pi-)eta and 3(pi+pi-)eta

Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector, the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and (7.24+-0.96+-1.11)X10^{-4}, respectively.Comment: 11 pages, 6 figure

A Measurement of Psi(2S) Resonance Parameters

Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been measured in the vicinity of the Psi(2S) resonance using the BESII detector operated at the BEPC. The Psi(2S) total width; partial widths to hadrons, pi+pi- J/Psi, muons; and corresponding branching fractions have been determined to be Gamma(total)= (264+-27) keV; Gamma(hadron)= (258+-26) keV, Gamma(mu)= (2.44+-0.21) keV, and Gamma(pi+pi- J/Psi)= (85+-8.7) keV; and Br(hadron)= (97.79+-0.15)%, Br(pi+pi- J/Psi)= (32+-1.4)%, Br(mu)= (0.93+-0.08)%, respectively.Comment: 8 pages, 6 figure

BESII Detector Simulation

A Monte Carlo program based on Geant3 has been developed for BESII detector simulation. The organization of the program is outlined, and the digitization procedure for simulating the response of various sub-detectors is described. Comparisons with data show that the performance of the program is generally satisfactory.Comment: 17 pages, 14 figures, uses elsart.cls, to be submitted to NIM

Measurement of branching fractions for the inclusive Cabibbo-favored ~K*0(892) and Cabibbo-suppressed K*0(892) decays of neutral and charged D mesons

The branching fractions for the inclusive Cabibbo-favored ~K*0 and Cabibbo-suppressed K*0 decays of D mesons are measured based on a data sample of 33 pb-1 collected at and around the center-of-mass energy of 3.773 GeV with the BES-II detector at the BEPC collider. The branching fractions for the decays D+(0) -> ~K*0(892)X and D0 -> K*0(892)X are determined to be BF(D0 -> \~K*0X) = (8.7 +/- 4.0 +/- 1.2)%, BF(D+ -> ~K*0X) = (23.2 +/- 4.5 +/- 3.0)% and BF(D0 -> K*0X) = (2.8 +/- 1.2 +/- 0.4)%. An upper limit on the branching fraction at 90% C.L. for the decay D+ -> K*0(892)X is set to be BF(D+ -> K*0X) < 6.6%

Search for the Lepton Flavor Violation Processes J/ψ→J/\psi \to μτ\mu\tau and eτe\tau

The lepton flavor violation processes $J/\psi \to \mu\tau$ and $e\tau$ are searched for using a sample of 5.8$\times 10^7$ $J/\psi$ events collected with the BESII detector. Zero and one candidate events, consistent with the estimated background, are observed in $J/\psi \to \mu\tau, \tau\to e\bar\nu_e\nu_{\tau}$ and $J/\psi\to e\tau, \tau\to\mu\bar\nu_{\mu}\nu_{\tau}$ decays, respectively. Upper limits on the branching ratios are determined to be $Br(J/\psi\to\mu\tau)<2.0 \times 10^{-6}$ and $Br(J/\psi \to e\tau) < 8.3 \times10^{-6}$ at the 90% confidence level (C.L.).Comment: 9 pages, 2 figure

Study of J/ψ→ωK+K−J/\psi \to \omega K^+K^-

New data are presented on $J/\psi \to \omega K^+K^-$ from a sample of 58M $J/\psi$ events in the upgraded BES II detector at the BEPC. There is a conspicuous signal for $f_0(1710) \to K^+K^-$ and a peak at higher mass which may be fitted with $f_2(2150) \to K\bar K$. From a combined analysis with $\omega \pi ^+ \pi ^-$ data, the branching ratio $BR(f_0(1710)\to\pi\pi)/BR(f_0(1710) \to K\bar K)$ is $< 0.11$ at the 95% confidence level.Comment: 11 pages, 5 figures. Submitted to Phys. Lett.