Proton inelastic scattering to continuum studied with antisymmetrized molecular dynamics

Intermediate energy (p,p$'$x) reaction is studied with antisymmetrized molecular dynamics (AMD) in the cases of $^{58}$Ni target with $E_p = 120$ MeV and $^{12}$C target with $E_p =$ 200 and 90 MeV. Angular distributions for various $E_{p'}$ energies are shown to be reproduced well without any adjustable parameter, which shows the reliability and usefulness of AMD in describing light-ion reactions. Detailed analyses of the calculations are made in the case of $^{58}$Ni target and following results are obtained: Two-step contributions are found to be dominant in some large angle region and to be indispensable for the reproduction of data. Furthermore the reproduction of data in the large angle region \theta \agt 120^\circ for $E_{p'}$ = 100 MeV is shown to be due to three-step contributions. Angular distributions for E_{p'} \agt 40 MeV are found to be insensitive to the choice of different in-medium nucleon-nucleon cross sections $\sigma_{NN}$ and the reason of this insensitivity is discussed in detail. On the other hand, the total reaction cross section and the cross section of evaporated protons are found to be sensitive to $\sigma_{NN}$. In the course of the analyses of the calculations, comparison is made with the distorted wave approach.Comment: 16 pages, 7 Postscript figure

Cross-polarized photon-pair generation and bi-chromatically pumped optical parametric oscillation on a chip

Nonlinear optical processes are one of the most important tools in modern optics with a broad spectrum of applications in, for example, frequency conversion, spectroscopy, signal processing and quantum optics. For practical and ultimately widespread implementation, on-chip devices compatible with electronic integrated circuit technology offer great advantages in terms of low cost, small footprint, high performance and low energy consumption. While many on-chip key components have been realized, to date polarization has not been fully exploited as a degree of freedom for integrated nonlinear devices. In particular, frequency conversion based on orthogonally polarized beams has not yet been demonstrated on chip. Here we show frequency mixing between orthogonal polarization modes in a compact integrated microring resonator and demonstrate a bi-chromatically pumped optical parametric oscillator. Operating the device above and below threshold, we directly generate orthogonally polarized beams, as well as photon pairs, respectively, that can find applications, for example, in optical communication and quantum optics

Binary projectile fragmentation of 12C at an incident energy of 33.3 MeV/nucleon

Direct binary projectile fragmentation is being investigated for the case where a 400 MeV 12C projectile breaks up into an particle and a 8Be fragment in the interaction with a thin 93Nb and 197Au target. While the 8Be fragments were measured at 9 , the correlated particles were detected in an angular range between 16 and 30 on the opposite side of the beam. From the preliminary results presented here one may obtain information on the amount of quasi-elastic fragmentation (both fragments do not suffer any further interactions after they are produced). These experimental results indicate that the quasi-elastic break-up process is the dominant contribution to the measured correlation spectra. As was also observed in earlier work, the most forward quasi-elastically emitted particles have energies exceeding the beam velocity

Study of the nucleon-induced preequilibrium reactions in terms of the Quantum Molecular Dynamics

The preequilibrium (nucleon-in, nucleon-out) angular distributions of $^{27}$Al, $^{58}$Ni and $^{90}$Zr have been analyzed in the energy region from 90 to 200 MeV in terms of the Quantum Moleculear Dynamics (QMD) theory. First, we show that the present approach can reproduce the measured (p,xp') and (p,xn) angular distributions leading to continuous final states without adjusing any parameters. Second, we show the results of the detailed study of the preequilibrium reaction processes; the step-wise contribution to the angular distribution, comparison with the quantum-mechanical Feshbach-Kerman-Koonin theory, the effects of momentum distribution and surface refraction/reflection to the quasifree scattering. Finally, the present method was used to assess the importance of multiple preequilibrium particle emission as a function of projectile energy up to 1 GeV.Comment: 22pages, Revex is used, 10 Postscript figures are available by request from [email protected]

Measurement of p + d -> 3He + eta in S(11) Resonance

We have measured the reaction p + d -> 3He + eta at a proton beam energy of 980 MeV, which is 88.5 MeV above threshold using the new ``germanium wall'' detector system. A missing--mass resolution of the detector system of 2.6% was achieved. The angular distribution of the meson is forward peaked. We found a total cross section of (573 +- 83(stat.) +- 69(syst.))nb. The excitation function for the present reaction is described by a Breit Wigner form with parameters from photoproduction.Comment: 8 pages, 2 figures, corrected typos in heade