51032910
Strong and radiative decays of the D(s0)*(2317) meson in the DK-molecule picture
We consider a possible interpretation of the new charm-strange meson D* s0 (2317) as a hadronic molecule-a bound state of D and K mesons. Using an effective Lagrangian approach, we calculate the strong D* s0 → D s π 0 and radiative D* s0 → D* s γ decays. A new impact related to the DK molecular structure of the D* s0 (2317) meson is that the presence of u(d) quarks in the D and K mesons gives rise to a direct strong isospin-violating transition D* s0 → D s π 0 in addition to the decay mechanism induced by η - π 0 mixing considered previously. We show that the direct transition dominates over the 17 - π 0 mixing transition in the D* s0 → D s π 0 decay. Our results for the partial decay widths are consistent with previous calculations.
119236022
Estimates for X ( 4350 ) decays from the effective Lagrangian approach
The strong and electromagnetic decays of X(4350) with quantum numbers J{sup P}=0{sup ++} and 2{sup ++} have been studied by using the effective Lagrangian approach. The coupling constant between X(4350) and D{sub s}*D{sub s0}* is determined with the help of the compositeness condition which means that X(4350) is a bound state of D{sub s}*D{sub s0}*. Other coupling constants applied in the calculation are determined phenomenologically. Our numerical results show that, using the present data, the possibility that X(4350) is a D{sub s}*D{sub s0}* molecule cannot be ruled out within the present model.
846321
ANOMALY AND ANOMALY-FREE TREATMENT OF QFT's BASED ON SYMMETRY-PRESERVING LOOP REGULARIZATION
The triangle anomaly in massless and massive QED is investigated by adopting the symmetry-preserving loop regularization method proposed recently in Refs. 1 and 2. The method is realized in the initial dimension of theory without modifying the original Lagrangian, it preserves symmetries under non-Abelian gauge and Poincare transformations in spite of the existence of two intrinsic mass scales Mc and μs which actually play the roles of UV- and IR-cutoff respectively. The axial-vector–vector-vector (AVV) triangle diagrams in massless and massive QED are evaluated explicitly by using the loop regularization. It is shown that when the momentum k of external state is soft with , m2 (m is the mass of loop fermions) and Mc → ∞, both massless and massive QED become anomaly free. The triangle anomaly is found to appear as quantum corrections in the case that m2, and Mc → ∞. Especially, it is justified that in the massless QED with μs = 0 and Mc → ∞, the triangle anomaly naturally exists as quantum effects in the axial-vector current when the ambiguity caused by the trace of gamma matrices with γ5 is eliminated by simply using the definition of γ5. It is explicitly demonstrated how the Ward identity anomaly of currents depends on the treatment for the trace of gamma matrices, which enables us to make a clarification whether the ambiguity of triangle anomaly is caused by the regularization scheme in the perturbation calculations or by the trace of gamma matrices with γ5. For comparison, an explicit calculation based on the Pauli–Villars regularization and dimensional regularization is carried out and the possible ambiguities of Ward identity anomalies caused from these two regularization schemes are carefully discussed, which include the ambiguities induced by the treatment of the trace of gamma matrices with γ5 and the action of the external momentum on the amplitude before the direct calculation of the AVV diagram.
118615785
Dense baryonic matter in conformally-compensated hidden local symmetry: Vector manifestation and chiral symmetry restoration
We find that, when the dilaton is implemented as a (pseudo-)Nambu-Goldstone boson using a conformal compensator or "conformon" in a hidden gauge symmetric Lagrangian written to $O(p^4)$ from which baryons arise as solitons, namely, skyrmions, the vector manifestation and chiral symmetry restoration at high density predicted in hidden local symmetry theory --- which is consistent with Brown-Rho scaling --- are lost or sent to infinite density. It is shown that they can be restored if in medium the behavior of the $\omega$ field is taken to deviate from that of the $\rho$ meson in such a way that the flavor $U(2)$ symmetry is strongly broken at increasing density. The hitherto unexposed crucial role of the $\omega$ meson in the structure of elementary baryon and multibaryon systems is uncovered in this work. In the state of half-skyrmions to which the skyrmions transform at a density $n_{1/2}^{} \gtrsim n_0^{}$ (where $n_0^{}$ is the normal nuclear matter density), characterized by the vanishing (space averaged) quark condensate but nonzero pion decay constant, the nucleon mass remains more or less constant at a value $\gtrsim$ 60 \% of the vacuum value indicating a large component of the nucleon mass that is not associated with the spontaneous breaking of chiral symmetry. We discuss its connection to the chiral-invariant mass $m_0^{}$ that figures in the parity-doublet baryon model.
118471203
P-WAVE MESON SPECTRUM IN A RELATIVISTIC MODEL WITH INSTANTON INDUCED INTERACTION
On the basis of the phenomenological relativistic harmonic models for quarks, we have obtained the masses of P-wave mesons. The full Hamiltonian used in the investigation has Lorentz scalar + vector confinement potential, along with one-gluon-exchange potential (OGEP) and the instanton-induced quark-antiquark interaction (III). A good agreement is obtained with the experimental masses. The respective role of III and OGEP for the determination of the meson masses is discussed.
8994892
Anomalous action in gauge invariant, nonlocal, dynamical quark model
Anomalous sector of chiral Lagrangian is calculated in a gauge invariant, nonlocal, dynamical quark model. The Wess-Zumino term is proved coming from two kinds of sources, one is independent of and another dependent on dynamical quark self energy Sigma(k(2)). p(6) and more higher order anomalous sectors come only from Sigma(k(2)) dependent source. After some cancellation, standard Wess-Zumino action is obtained. (C) 2003 Published by Elsevier Science B.V.
122947463
COSMIC RAY MUON MEASUREMENT BY L3 SPECTROMETER AT CERN
L3 + C is a branch experiment on L3 magnet spectrometer, which is located on the ring of LEP accelerator at CERN. To take the advantage of L3 muon chambers in its low threshold, wide dynamic range and high resolution, the momentum of cosmic ray muons in the range of 15–2000 GeV/c at a shallow depth of 30 m of molasse can be measured precisely. Since 1998, a scintillator detector system, a new fast trigger and DAQ system, and a small air shower array had been established for study the CR muon events independently. Up to August 2000, 8 billion muons and 25 million air shower events had been recorded. The first results for CR muon spectrum and the charge ratio etc. had been obtained.
117504817
The X-ray spectra and XUV excess of some AGNs.
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.
123323228
Test of Monte-Carlo model with the L3+C muon spectrum measurement
The paper shows good agreement between the atmospheric muon spectra measured by L3+C and the COMUGEN Monte-Carlo model. The atmospheric neutrino spectrum is inferred.
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.