10430765
Evidence for neutral B meson decays to omegaK*0.
We present the results of a study of the charmless vector-vector decay B0-->omegaK*0 with 657 x 10(6) BB pairs collected with the Belle detector at the KEKB e+e- collider. We measure the branching fraction to be B(B0-->omegaK*0) = [1.8+/-0.7(stat)+/-0.3(syst)]x 10(-6) with 3.0sigma significance. We also perform a helicity analysis of the omega and K*0 vector mesons, and obtain the longitudinal polarization fraction fL(B0-->omegaK*0) = 0.56+/-0.29(stat) -0.08(+0.18)(syst). Finally, we measure a large nonresonant branching fraction B[B0-->omegaK+pi(-);M Kpi in(0.755,1.250) GeV/c2] = [5.1+/-0.7(stat)+/-0.7(syst)]x 10(-6) with a significance of 9.5sigma.
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.
124556172
Searches for charmless decays $B^0 \to \eta \omega$, $B^0 \to \eta K^0$, $B^{+} \to \eta \rho^{+}$, and $B^{+} \to \eta^\prime \pi^{+}$
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.
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%.
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.
121930739
Searches for cosmic-ray electron anisotropies with the Fermi Large Area Telescope
The Large Area Telescope on board the Fermi satellite (Fermi LAT) detected more than 1.6 x 10(6) cosmic-ray electrons/positrons with energies above 60 GeV during its first year of operation. The ar ...
27791621
The radio/gamma-ray connection in active galactic nuclei in the era of the Fermi large area telescope
We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose. We use both archival interferometric 8.4 GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15 GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100 MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of < 10(-7) for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 x 10(-6) to 9.0 x 10(-8). Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability < 10(-7)) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.
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.
67754985
Constraints on the Cosmic-ray Density Gradient Beyond the Solar Circle from Fermi γ-ray Observations of the Third Galactic Quadrant
We report an analysis of the interstellar ?-ray emission in the third Galactic quadrant measured by the Fermi Large Area Telescope. The window encompassing the Galactic plane from longitude 210? to 250? has kinematically well-defined segments of the Local and the Perseus arms, suitable to study the cosmic-ray (CR) densities across the outer Galaxy. We measure no large gradient with Galactocentric distance of the ?-ray emissivities per interstellar H atom over the regions sampled in this study. The gradient depends, however, on the optical depth correction applied to derive the H?I column densities. No significant variations are found in the interstellar spectra in the outer Galaxy, indicating similar shapes of the CR spectrum up to the Perseus arm for particles with?GeV to tens of?GeV energies. The emissivity as a function of Galactocentric radius does not show a large enhancement in the spiral arms with respect to the interarm region. The measured emissivity gradient is flatter than expectations based on a CR propagation model using the radial distribution of supernova remnants and uniform diffusion properties. In this context, observations require a larger halo size and/or a flatter CR source distribution than usually assumed. The molecular mass calibrating ratio, X CO = N(H2)/W CO, is found to be (2.08 ? 0.11) ? 1020 cm-2(K km s?1)?1 in the Local arm clouds and is not significantly sensitive to the choice of H I spin temperature. No significant variations are found for clouds in the interarm region.
124682883
A geometric factor calculation method based on the isotropic flux assumption
One of the instruments onboard the China Seismic Electromagnetic Satellite (CSES) is the Low Energy Particle Detector (LEPD). The primary objective of LEPD is to provide measurements of the fluxes, energy spectra and pitch angles of 100 keV to 10 MeV electrons and protons from 2 to 50 MeV in the Earth's magnetosphere. The geometric factor is one of the principle parameters of a detector, which converts the physical quantity count rate to the particle quantity-flux. In this paper, we calculated the geometric factor of LEPD via computer modeling of an isotropic radiation environment. It was first demonstrated that the radiation intensity related should obey a cosine-law, then a general sampling method of generating this distribution via CPS of GEANT4 was explained. Furthermore, combined with flux normalization, a comparison of the geometric factor calculation of a set of 2-layer detectors with different shapes (cylinder, truncated cone and rectangle) was performed. Results show a generally good agreement between simulation and analytical calculations for the cylinder and truncated cone detectors, and the result of the rectangular one, for which there is no accurate analytical formula, is consistent with the previous simulated results by others. As a practical instance of the 2-layer rectangle detector, the geometric factor of LEPD is 10.336 +/- 0.036 cm(2).sr for 10 MeV proton and 8.211 +/- 0.032 cm(2).sr for 8 MeV electron.