73685393
First moments of nucleon generalized parton distributions
We extrapolate the first moments of the generalized parton distributions using heavy baryon chiral perturbation theory. The calculation is based on the one loop level with the finite range regularization. The description of the lattice data is satisfactory, and the extrapolated moments at physical pion mass are consistent with the results obtained with dimensional regularization, although the extrapolation in the momentum transfer to t = 0 does show sensitivity to form factor effects, which lie outside the realm of chiral perturbation theory. We discuss the significance of the results in the light of modern experiments as well as QCD inspired models.
123370023
Chiral symmetry restoration of nuclear matter
The phase transition of chiral symmetry restoration of nuclear matter is studied in the chiral SU(3) quark mean field model. For some kinds of confining potentials, there exists a critical density ρc. When the baryon density is larger than ρc, nuclear matter will be in the phase of chiral symmetry restoration. At critical density, the physical quantities change discontinuously. The critical density will become larger when the vector part of the confining potential increases.
121034531
Strange hadronic matter in a chiral model
The strange hadronic matter with nucleon, Λ-hyperon and Ξ-hyperon is studied by using a chiral symmetry model in a mean-field approximation. The saturation properties and stabilities of the strange hadronic matter are discussed. The result indicates a quite large strangeness fraction (fS) region where the strange hadronic matter is stable against particle emission. In the large fS region, the Ξ component dominates, resulting in a deep minimum in the curve of the binding energy per baryon EB versus the strangeness fraction fS with (EB, fS) (-26.0 MeV, 1.23).
118632293
Nucleon magnetic form factors with non-local chiral effective Lagrangian
Chiral perturbation theory is a useful method to investigate the hadron properties. We apply the non-local chiral effective Lagrangian to study the nucleon magnetic form factors. The octet and decuplet intermediate states are included in the one-loop calculation. With the modified propagators and non-local interaction, the loop integral is convergent. The obtained proton and neutron magnetic form factors are both reasonable up to relatively large Q2.
117796835
Static three-body potential in baryons
The first principle of quantum chromodynamics is used to calculate the static perturbative three-body potential between three valence quarks in baryons, which is gauge invariant and flavor-dependent, and of magnitude of the same order as the next non-leading static q-q potential. Its effect on an S-state baryon composed of three valence quarks of equal mass may be viewed as a slight increase of the constituent quark masses with respect to those in mesons.
121124456
An Extended Chiral SU(3) Quark Model
The chiral SU(3) quark model is extended by including the vector meson exchanges to describe the short range interactions. The phase shifts of NN scattering are studied in this model. Compared with the results of the chiral SU(3) quark model in which only the pseudo-scalar and scalar chiral fields are considered, the phase shifts of 1S0 wave are obviously improved.
25602732
Measurement of the differential branching fraction and forward-backward asymmetry for B --> K(*)l+l-.
We study B --> K(*)l+l- decays (l = e, mu) based on a data sample of 657 x 10(6) BB pairs collected with the Belle detector at the KEKB e+e- collider. We report the differential branching fraction, isospin asymmetry, K* polarization, and the forward-backward asymmetry (A(FB)) as functions of q2 = M(ll)(2)c2. The fitted A(FB) spectrum exceeds the standard model expectation by 2.7 standard deviations. The measured branching fractions are B(B --> K*l+l-) = (10.7(-1.0)(+1.1) +/- 0.9) x 10(-7) and B(B --> Kl+l-) = (4.8(-0.4)(+0.5) +/- 0.3) x 10(-7), where the first errors are statistical and the second are systematic, with the muon to electron ratios R(K*) = 0.83 +/- 0.17 +/- 0.08 and R(K) = 1.03 +/- 0.19 +/- 0.06.
118683866
Search for heavy neutrinos at Belle
We report on a search for heavy neutrinos in $B$-meson decays. The results are obtained using a data sample that contains $772\ifmmode\times\else\texttimes\fi{}{10}^{6}B\overline{B}$ pairs collected at the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. No signal is observed and upper limits are set on mixing of heavy neutrinos with left-handed neutrinos of the Standard Model in the mass range $0.5--5.0\text{ }\text{ }\mathrm{GeV}/{c}^{2}$.
123057858
Fermi/LAT observations of LS 5039
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray Space Telescope data between 2008 August and 2009 June are presented. Our results indicate variab ...
209833820
Search for leptonic decays of D0 mesons
We search for the flavor-changing neutral current decays D-0 -> mu(+)mu(-) and D-0 -> e(+)e(-), and for the lepton-flavor violating decays D-0 -> e(+/-)mu(-/+) using 660 fb(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We find no evidence for any of these decays. We obtain significantly improved upper limits on the branching fractions: B(D-0 -> mu(+)mu(-)) e(+)e(-)) e(+)mu(-)) + B(D-0 -> mu(+)e(-)) < 2.6 x 10(-7) at 90% confidence level.
62821553
High-statistics study of K0S pair production in two-photon collisions
We report a high-statistics measurement of the differential cross section of the process gamma gamma -> (KSKS0)-K-0 in the range 1.05 GeV (KSKS0)-K-0 is reported. The detailed behavior of the cross section is updated and compared with QCD-based calculations.