119292653
Wave functions and decay constants of B and D mesons in the relativistic potential model
With the decay constants of D and Ds mesons measured in experiment recently, we revisit the study of the bound states of quark and antiquark in B and D mesons in the relativistic potential model. The relativistic bound state wave equation is solved numerically. The masses, decay constants and wave functions of B and D mesons are obtained. Both the masses and decay constants obtained here can be seen as consistent with the experimental data. The wave functions can be used in the study of B and D meson decays.
118395218
Rare semileptonic decays of heavy mesons with flavor SU(3) symmetry
AbstractIn this paper, we calculate the decay rates of the D+→D0e+ν, DS+→D0e+ν, 
$B^{0}_{S}\rightarrow B^{+}e^{-}\overline{\nu}$
, DS+→D+e−e+ and BS0→B0e−e+ semileptonic decay processes, in which only the light quarks decay, while the heavy flavors remain unchanged. The branching ratios of these decay processes are calculated with the flavor SU(3) symmetry. The uncertainties are estimated by considering the SU(3) breaking effect. We find that the decay rates are very tiny in the framework of the standard model. We also estimate the sensitivities of the measurements of these rare decays at future experiments, such as BES-III, super-B and LHC-b.
119288185
Radiative and leptonic decays of the pseudoscalar charmonium state eta(c)
The radiative and leptonic decays of {eta}{sub c}{yields}{gamma}{gamma} and {eta}{sub c}{yields}l{sup +}l{sup -} are studied. For a {eta}{sub c}{yields}{gamma}{gamma} decay, the second-order electromagnetic tree-level diagram gives the leading contribution. The decay rate of {eta}{sub c}{yields}{gamma}{gamma} is calculated, the prediction is in good agreement with the experimental data. For {eta}{sub c}{yields}l{sup +}l{sup -}, both the tree and loop diagrams are calculated. The analysis shows that the loop contribution dominates; the contribution of tree diagram with a Z{sup 0} intermediate state can only modify the decay rate by less than 1%. The prediction of the branching ratios of {eta}{sub c}{yields}e{sup +}e{sup -} and {mu}{sup +}{mu}{sup -} are very tiny within the standard model. The smallness of these predictions within the standard model makes the leptonic decays of {eta}{sub c} sensitive to physics beyond the standard model. Measurement of the leptonic decay may give information about new physics.
119388505
Sudakov effects in BBNS approach
The end-point singularity is an unsolved problem in BBNS approach, Incorporating the partonic transverse momentum and the Sudakov form factor, this problem can be solved model-independently. We discuss the Sudakov effects in BBNS approach. The BBNS approach is compared with the modified PQCD approach. The main idea of Sudakov form factor is briefly discussed. Our conclusion is that the twist-3 contribution for the hard spectator scattering is numerically not important in B --> pi pi decays, compared with the twist-2 contribution. (C) 2001 Published by Elsevier Science B.V.
116060100
The Decay of the Z boson into three photons via W boson loops
119017430
B ---> PV decays in QCD improved factorization approach
Motivated by recent CELO measurements and the progress of the theory of B decays, we investigate $B\to P V(P=\pi,K. V= K^{*},\rho,\omega)$ decay modes in the framework of QCD improved factorization. We find that all the measured branching ratios are well accommodated in the reasonable parameter space and predictions for the other decay modes are well below the experimental upper limits. We also have calculated CP asymmetries in these decay modes.
119117884
Proceedings of the 2nd Workshop on Flavor Symmetries and Consequences in Accelerators and Cosmology (FLASY12)
Although existing theoretical models generally prefer extremely heavy right-handed neutrinos to generate light neutrino masses via the seesaw mechanism, there are several observed phenomena that point to the existence of both keVand eV-scale sterile neutrinos. We present two A4 flavor symmetry models that can accommodate light sterile neutrinos and remain compatible with neutrino data. Higher order seesaw terms and higher-dimensional operators are studied, and the phenomenological implications of light sterile neutrinos on neutrinoless double beta decay are discussed. 1.
119119152
Analysis of a selected sample of RR Lyrae stars in the LMC from OGLE-III
A systematic study of RR Lyrae stars is performed using a selected sample of 655 objects in the Large Magellanic Cloud (LMC) with long-term observations and numerous measurements from the Optical Gravitational Lensing Experiment III project. The phase dispersion method and linear superposition of the harmonic oscillations are used to derive the pulsation frequency and properties of light variation. It is found that a dichotomy exists in Oosterhoff Type I and Oosterhoff Type II for RR Lyrae stars in the LMC. Due to our strict criteria for identifying a frequency, a lower limit for the incidence rate of Blazhko modulation in the LMC is estimated in various subclasses of RR Lyrae stars. For fundamental-mode RR Lyrae stars, the rate of 7.5% is smaller than the previous result. In the case of the first-overtone RR Lyrae variables, the rate of 9.1% is relatively high. In addition to the Blazhko variables, 15 objects are identified to pulsate in the fundamental/first-overtone double mode. Furthermore, four objects show a period ratio around 0.6, which makes them very likely to be rare pulsators in the fundamental/second-overtone double mode.
119474898
The topological branching fractions of $\tau$ decay at LEP
The paper has heen withdrawn.
27697160
350 μm Observations of Ultraluminous Infrared Galaxies at Intermediate Redshifts
We present 350 μm observations of 36 ultraluminous infrared galaxies (ULIRGs) at intermediate redshifts (0.089 ≤ z ≤ 0.926) using the Submillimeter High Angular Resolution Camera II (SHARC-II) on the Caltech Submillimeter Observatory (CSO). In total, 28 sources are detected at S/N ≥ 3, providing the first flux measurements longward of 100 μm for a statistically significant sample of ULIRGs in the redshift range 0.1 ≲ z ≲ 1.0. Combining our 350 μm flux measurements with the existing IRAS 60 and 100 μm data, we fit a single-temperature model to the spectral energy distribution (SED) and thereby estimate dust temperatures and far-IR luminosities. Assuming an emissivity index of β = 1.5, we find a median dust temperature and far-IR luminosity of T_d = 42.8 ± 7.1 K and log(L_(FIR)/L_☉) = 12.2 ± 0.5, respectively. The far-IR-radio correlation observed in local star-forming galaxies is found to hold for ULIRGs in the redshift range 0.1 ≲ z ≲ 0.5, suggesting that the dust in these sources is predominantly heated by starbursts. We compare the far-IR luminosities and dust temperatures derived for dusty galaxy samples at low and high redshifts with our sample of ULIRGs at intermediate redshift. A general L_(FIR)-T_d relation is observed, albeit with significant scatter due to differing selection effects and variations in dust mass and grain properties. The relatively high dust temperatures observed for our sample compared to that of high-z submillimeter-selected starbursts with similar far-IR luminosities suggest that the dominant star formation in ULIRGs at moderate redshifts takes place on smaller spatial scales than is found at higher redshifts.
121541983
Designs and measurements of gradient dipole magnets for the upgrade of Pohang Light Source
Abstract The compact size of the upgrade of Pohang Light Source (PLS-II) ring implies the use of gradient dipole magnets, with high field quality requirements. The PLS-II ring contains 24 such dipoles. Detailed 2D and 3D physical designs are reported; they include conformal mapping, equivalent 2D compact factor, residues fitting technique and end chamfer in a concise straight line style. According to the field measurement results, a beam based alignment technique for the rms variation reduction was employed. With that, the uniformities for these dipoles can be reduced to less than 2.0E−04, and the rms variation from dipole to dipole can reach 5.82E-04.