120406708
Analysis methods for results in gamma-ray astronomy
118365916
Geminga Pulsar in Cos-B and Heao-B Observations
115136998
Search for a Muon Flux Enhancement During the Solar Flare of 14 July 2000 with the L3+C Data
The solar slare of the 14 July 2000 offers a unique opportunity for the L3+C experiment at CERN to search for a correlated enhancement in the flux of muons using the precision spectrometer. The search for a directional excess in the flux of muons between 15 and 25 GeV, corresponding to primary proton energies above 40 GeV, is presented. We report an excess with a chance probability of 2.7 · 10−3 at a time coincident with the peak increase of solar protons observed with neutron monitors and satellites. At higher energies no significant signal has been observed up to 1.5 hours after the Solar flare time.
123957691
Study on a Cellmap for the Reconstruction of Cosmic Ray Tracks in Drift Chamber
Taking L3 Cosmics experiment (L3 + C) as an example, we discussed a new Cellmap to reconstruct the hit in drift chamber of magnetic spectrometer for the very inclined comic-ray tracks, and compared the reconstruction results with the standard Cellmap of L3 + C. It shows that, for the very inclined cosmic-ray tracks, the new Cellmap can reconstruct more hits than the standard Cellmap, and the distribution of chi(2) of track reconstruction is also improved.
121855913
Possibility to Detect Upgoing Sleptons
Some supersymmetric models predict long lived charged sleptons. If they are exist, the τ ˜ , the supersymmetry partner of τ lepton, could be produced inside the earth by collisions of high energy neutrinos with nucleons. The possible signals of upgoing τ ˜ have been studied in various ways. Taking the atmospheric neutrino flux into account, the muon flux as main background is also estimated. By using the Waxman-Bahcall limit on the extraterrestrial neutrino flux, the resultant spectra show that there are about 70 events per year passing a km-scale underground experiment, such as ICECUBE.
117504817
The X-ray spectra and XUV excess of some AGNs.
119298268
Lepton-number-violating decays of B+, D+, and D+s mesons induced by the doubly charged Higgs boson
The lepton-number-violating decays of B+, D+, and D-s(+) mesons induced by the doubly charged Higgs boson have been studied. It is found that although the yielded results of the branch ratio are much smaller than the present limits from the data, they are consistent with the previous conclusions calculated in the framework of the relativistic quark model where the processes happened via light Majorana neutrinos.
118442618
Strong and electromagnetic decays of X(1835) as a baryonium state
With the assumption that the recently observed X(1835) is a baryonium state we have studied the strong decays of X(1835) → η(')π+π−, η(')π0π0 and the electromagnetic decay of X(1835) → 2γ in the framework of effective Lagrangian formalism. In the present investigation, we have included the contributions from the iso-singlet light scalar resonances but we have not included the isospin violating effect. Our result for the strong decay of X(1835) → η'π+π− is smaller than the observed data. The decay width for the radiative decay of X(1835) → 2γ is consistent with the assumption that it decays through the glueball. In addition, the width for the strong decay of X(1835) → ηπ+π− is larger than that for the strong decay of X(1835) → η'π+π− due to the large phase space and coupling constant . From our investigation, it is not possible to interpret X(1835) as a baryonium.
117659262
Properties of the Scalar Mesons below 1.0-GeV as Hadronic Molecules
Properties of scalar mesons below 1.0 GeV have been studied by regarding them as hadronic molecular states. Using the effective Lagrangian approach, we have calculated their leptonic decays, strong decays and productions via the $\phi$ meson radiative decays. Comparing our results with that given in the literature and the data, we conclude that it is difficult to arrange them in the same nonet if some of them are pure hadronic molecules.
59430684
Chiral partner structure of heavy baryons from the bound state approach with hidden local symmetry
The chiral partner structure of heavy baryons is studied using the bound state approach by binding the heavy-light mesons to the nucleon as the soliton in an effective Lagrangian for the pseudoscalar and vector mesons based on hidden local symmetry. In the heavy-light meson sector, we regard the $H$ doublet and $G$ doublet as chiral partners and couple them to light mesons with a minimal derivative. We find that the chiral partner of ${\ensuremath{\Lambda}}_{c}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{+}}{},2286)$ is the ${\ensuremath{\Lambda}}_{c}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{\ensuremath{-}}}{},\frac{3}{2}\genfrac{}{}{0}{}{{}^{\ensuremath{-}}}{})$ heavy quark doublet with a mass of about 3.1 GeV but not (${\ensuremath{\Lambda}}_{c}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{\ensuremath{-}}}{},2595)$, ${\ensuremath{\Lambda}}_{c}(\frac{3}{2}\genfrac{}{}{0}{}{{}^{\ensuremath{-}}}{},2625)$), which might be interpreted as an orbital excitation of ${\ensuremath{\Lambda}}_{c}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{+}}{},2286)$. The same model is applied to the bottom sector, and the chiral partner of ${\ensuremath{\Lambda}}_{b}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{+}}{},5625)$ is shown to have a mass of about 6.5 GeV. We also discuss the chiral partner structures for the isospin vector heavy baryons. For the pentaquark states, we find that the masses of the pentaquark state made of a ground state heavy-light meson and its chiral partner are similar, and both of them are below the $Dp$ threshold, which therefore cannot be ruled out by the present data.
14229719
The Classical geometry from a physical state in canonical quantum gravity
We construct a weave state which approximates a degenerate 3-metric of rank 2 at large scales. It turns out that a non-degenerate metric region can be evolved from this degenerate metric by the classical Ashtekar equations, hence the degeneracy of 3-metrics is not preserved by the evolution of Ashtekar's equations. As the s-knot state corresponding to this weave is shown to solve all the quantum constraints in loop quantum gravity, a physical state in canonical quantum gravity is related to the familiar classical geometry.