CP Test in J/Psi -> gamma phi phi Decay

We propose to test CP symmetry in the decay \jp\to \gamma \phi\phi, for which large data sample exists at BESII, and a data sample of $10^{10}$ $J/\psi$'s will be collected with BESIII and CLEO-C program. We suggest some CP asymmetries in this decay mode for CP test. Assuming that CP violation is introduced by the electric- and chromo-dipole moment of charm quark, these CP asymmetries can be predicted by using valence quark models. Our work shows a possible way to get information about the electric- and chromo-dipole moment of charm quark, which is little known. Our results show that with the current data sample of $J/\psi$, electric- and chromo-dipole moment can be probed at order of $10^{-14}e cm$. In the near future with a $10^{10}$ data sample, these moments can be probed at order of $10^{-16}e cm$.Comment: Misprints corrected. To appear in Phys. Lett.

Some properties of the newly observed X(1835) state at BES

Recently the BES collaboration has announced observation of a resonant state in the $\pi^+\pi^- \eta'$ spectrum in $J/\psi \to \gamma \pi^+\pi^-\eta'$ decay. Fitting the data with a $0^{-+}$ state, the mass is determined to be 1833.7 MeV with $7.7\sigma$ statistic significance. This state is consistent with the one extracted from previously reported $p \bar p$ threshold enhancement data in $J/\psi \to \gamma p \bar p$. We study the properties of this state using QCD anomaly and QCD sum rules assuming X(1835) to be a pseudoscalar and show that it is consistent with data. We find that this state has a sizeable matrix element $$ leading to branching ratios of $(2.61\sim 7.37)\times 10^{-3}$ and $(2.21\sim 10.61)\times 10^{-2}$ for $J/\psi \to \gamma G_p$ and for $G_p \to \pi^+\pi^- \eta'$, respectively. Combining the calculated branching ratio of $J/\psi \to \gamma G_p$ and data on threshold enhancement in $J/\psi \to \gamma p \bar p$, we determine the coupling for $G_p- p-\bar p$ interaction. We finally study branching ratios of other $J/\psi \to \gamma + {three mesons}$ decay modes. We find that $J/\psi \to \gamma G_p \to \gamma (\pi^+\pi^- \eta, K K \pi^0)$ can provide useful tests for the mechanism proposed.Comment: 13 pages, 3 figures. The final version to appear at EPJ

A study of the centrally produced pi0pi0pi0 channel in pp interactions at 450 GeV/c

The reaction pp -> pf (pi0pi0pi0) ps has been studied at 450 GeV/c. The pi0pi0pi0 effective mass spectrum shows clear eta(547) and pi2(1670) signals. Branching ratios for the eta(547) and pi_2(1670) are given as well as upper limits for the decays of the omega(782), a1(1260) and a2(1320) into 3pi0.Comment: 10 pages, Latex, 4 Figure

Near Threshold Enhancement of p pbar System and p pbar Elastic Scattering

The observed enhancement of $p\bar p$-production near the threshold in radiative decays of $J/\psi$ and $e^+e^-$-annihilations can be explained with final state interactions among the produced $N\bar N$ system, where the enhancement is essentially determined by $N\bar N$ elastic scattering amplitudes. We propose to use an effective theory for interactions in a $N\bar N$ system near its threshold. The effective theory is similar to the well-known one for interactions in a $NN$ system but with distinctions. It is interesting to note that in the effective theory some corrections to scattering amplitudes at tree-level can systematically be summed into a simple form. These corrections are from rescattering processes. With these corrected amplitudes we are able to describe the enhancement near the threshold in radiative decays of $J/\psi$ and $e^+e^-$-annihilations, and the $p\bar p$ elastic scattering near the threshold.Comment: Discussions and References added, Fig.2 redrawn. Published version in Phys. Lett.

A coupled channel analysis of the centrally produced K+K- and pi+pi- final states in pp interactions at 450 GeV/c

A coupled channel analysis of the centrally produced K+K- and pi+pi- final states has been performed in pp collisions at an incident beam momentum of 450 GeV/c. The pole positions and branching ratios to pipi and KK of the f0(980), f0(1370), f0(1500) and f0(1710) have been determined. A systematic study of the production properties of all the resonances observed in the pi+pi- and K+K- channels has been performed.Comment: 16 pages, Latex, 5 Figure

A measurement of the branching fractions of the f1(1285) and f1(1420) produced in central pp interactions at 450 GeV/c

A study of the f1(1285) and f1(1420) produced in central pp interactions has been performed. For the first time in a single experiment the branching fractions of both mesons in all major decay modes have been determined. Both the f1(1285) and f1(1420) are consistent with being produced by double Pomeron exchange.Comment: 15 pages, Latex, 5 Figures, submitted to Physics Letters

Hadron yields and spectra in Au+Au collisions at the AGS

Inclusive double differential multiplicities and rapidity density distributions of hadrons are presented for 10.8 A GeV/c Au+Au collisions as measured at the AGS by the E877 collaboration. The results indicate that large amounts of stopping and collective transverse flow effects are present. The data are also compared to the results from the lighter Si+Al system.Comment: 12 pages, latex, 10 figures, submitted to Nuclear Physics A (Quark Matter 1996 Proceedings

Ion-beam-induced reconstruction of amorphous GaN

Wurtzite GaN can be rendered amorphous by high-dose heavy-ion bombardment. We show here that relatively low-dose reirradiation of such amorphous GaN (a-GaN) with MeV light ions can significantly change some of the physical properties of a-GaN. In particular, light-ion reirradiation of a-GaN results in (i) an increase in material density, (ii) the suppression of complete decomposition during postimplantation annealing, (iii) a significant increase in the values of hardness and Young's modulus, and (iv) an apparent decrease in the absorption of visible light. Transmission electronmicroscopy shows that a-GaN remains completely amorphous after light-ion reirradiation. Therefore, we attribute the above effects of light-ion reirradiation to an ion-beam-induced atomic-level reconstruction of the amorphous phase. Results indicate that electronic energy loss of light ions is responsible for the changes in the mechanical properties and for the suppression of thermally induced decomposition of a-GaN. However, the changes in the density of a-GaN appear to be controlled by the nuclear energy loss of light ions

Conditional generation of arbitrary multimode entangled states of light with linear optics

We propose a universal scheme for the probabilistic generation of an arbitrary multimode entangled state of light with finite expansion in Fock basis. The suggested setup involves passive linear optics, single photon sources, strong coherent laser beams, and photodetectors with single-photon resolution. The efficiency of this setup may be greatly enhanced if, in addition, a quantum memory is available.Comment: 7 pages, 5 figure

Existence of the σ\sigma-meson below 1 GeV and f0(1500)f_0(1500) glueball

On the basis of a simultaneous description of the isoscalar s-wave channel of the $\pi\pi$ scattering (from the threshold up to 1.9 GeV) and of the $\pi\pi\to K\bar{K}$ process (from the threshold to $\sim$ 1.4 GeV) in the model-independent approach, a confirmation of the $\sigma$-meson at $\sim$ 665 MeV and an indication for the glueball nature of the $f_0(1500)$ state are obtained. It is shown that the large $\pi\pi$-background, usually obtained, combines, in reality, the influence of the left-hand branch-point and the contribution of a very wide resonance at $\sim$ 665 MeV. The coupling constants of the observed states with the $\pi\pi$ and $K\bar{K}$ systems and lengths of the $\pi\pi$ and $K\bar{K}$ scattering are obtained.Comment: 13 pages, 3 figures, LaTex; submitted to Physics Letters