204932941
GRB 050315: A step toward the uniqueness of the overall GRB structure and the true nature of long GRBs
Using the Swift data of GRB 050315, we progress on the uniqueness of our theoretically predicted Gamma-Ray Burst (GRB) structure as composed by a proper-GRB (P-GRB), emitted at the transparency of an electron-positron plasma with suitable baryon loading, and an afterglow comprising the so called "prompt emission" as due to external shocks. Thanks to the Swift observations, we can theoretically fit detailed light curves for selected energy bands on a continuous time scale ranging over 10^6 seconds. The theoretically predicted instantaneous spectral distribution over the entire afterglow confirms a clear hard-to-soft behavior encompassing, continuously, the "prompt emission" all the way to the latest phases of the afterglow. Consequences of the instrumental threshold on the definition of "short" and "long" GRBs are discussed.
119409603
Chiral gauged fermions on a lattice
Abstract The chiral fermion model with local multifermion interactions proposed in Nucl. Phys. B 486 (1997) 282 and Phys. Rev. D 61 (2000) 054502 processes an exact SU L (2) chiral gauge symmetry and SU L (2)⊗ U R (1) chiral flavour symmetry on a lattice and a plausible scaling region for the target chiral gauge theory in the continuum limit. Following the previous analysis of massive and massless fermion spectra in the scaling region, we compute the one-particle-irreducible coupling vertices between gauge field and fermions by the strong multifermion coupling expansion and analytical continuation of these vertex functions in the momentum space. We show a peculiar scenario that a massless fermion is SU L (2)-chirally gauged in the low energy and 15 non-degenerate massive Dirac fermions are SU L (2)-vectorially gauged at the lattice scale O (1/ a ). The Ward identities associated to the chiral gauge symmetry are realized by both the massless chiral fermion and massive Dirac fermions. These Ward identities protect the perturbative calculations in the small gauge coupling from hard gauge-symmetry breakings and lead to the normal gauge-invariant renormalization prescription. The vacuum functional is perturbatively computed by a continuum regularization scheme in 16 edges of Brillouin zones. We achieve the correct form of the gauge anomaly and U L (1) fermion-flavour singlet anomaly with the soft chiral symmetry breaking scale that is much smaller than the lattice scale. The residual breakings of chiral gauge symmetry after the gauge anomaly cancellation are eliminated in the normal gauge-invarinant renormalization prescription. We discuss the consistency of the scenario and the reasons for it to work for perturbative and non-perturbative gauge field.
124770809
The Casimir Effect in Perfectly Conducting Rectangular Cavity
123506354
CASIMIR EFFECT OF SCALAR FIELD ON SN-1 MANIFOLD
Casimir effect of scalar field on R4 × Sn-1 manifolds is evaluated. The results show that compactness of manifolds S1 and S2 can be held by Casimir force. However, other compact spaces (Sn-1, n > 3) are unstable.
29582274
Chiral Schwinger model and lattice fermionic regularizations.
The chiral Schwinger model is studied on the lattice with use of Wilson fermions. The arbitrary mass term for the gauge boson is shown to originate from the arbitrariness of the Wilson parameter, which is required to avoid the doubling phenomenon on the lattice. The necessity for such a term is thus demonstrated in contrast to the mere admissibility as indicated by previous continuum calculations.
123648318
Stochastic quantization of fermions on lattice
The stochastic quantization approach is generalized to the case of fermions on lattice. The approximate approaches for solving Langevin equation are analysed.
125260045
Evidence of sigma particle in J / psi ---> omega pi pi
122025900
Search for supersymmetric particles using acoplanar charged-particle pairs from Z0 decays
We have performed a search for supersymmetric particles using acoplanar pairs of oppositely-charged particles in decays of the Z0. In 0.53 pb−1 of integrated luminosity near the Z0 peak, we observe two events where approximately four are expected from background, allowing limits to be extended on combined photino and slepton masses, and also on combined photino and chargino masses.
122313186
Search For Neutral Higgs Bosons From Supersymmetry In Z-decays
The light scalar Higgs boson h and the pseudoscalar Higgs boson A of the minimal supersymmetric standard model have been searched for in the processes e+e−→hff and e+e−→hA using data collected by ALEPH at the LEP e+e− collider, with center of mass energies at and near the Z peak. Using a variety of signatures adapted to various mass ranges for h and A, we have excluded a large domain in the parameter space. For large values of ν2ν1, the ratio of the vacuum expectation values of the two Higgs fields, the whole range from 0 to 38.8 GeV is excluded for Mh and MA at 95% CL.
124674675
EXPERIMENTAL STUDY OF J/PSI RADIATIVE DECAY TO PI 0PI 0
121321199
The timing properties of a plastic time-of-flight scintillator from a beam test
The properties of a time-of-flight scintillator bar, EJ-200, wrapped with different reflective materials, were studied using 800MeV/c electron beam at the test beam of IHEP in China. It is 230 cm long with a cross-section of 5 x 6 cm 2, viewed from both ends by R5924 photomultiplier tubes. The results show that the time resolution and the attenuation length depend on the reflective materials. (c) 2005 Elsevier B.V. All rights reserved.