Causality principle and nuclear dispersion anomaly in the elastic scattering for α+12C system

The optical model analysis of the alpha particle elastic scattering on a carbon target was performed on the basis of the dispersion relation between the real and imaginary parts of     

1 GeV proton elastic scattering on 9Be nuclei in the α-cluster model with dispersion

The polarization observables for the elastic p- ⁹Be scattering at 1GeV are calculated on the basis of the multiple-diffraction scattering theory and the -cluster model with dispersion. The ⁹Be nucleus is considered as composed of two -clusters and a neutron arranged at the vertices of an isosceles triangle. The results obtained are in agreement with existing experimental data.     

Search for the neutrino magnetic moment in the elastic νe scattering

The possibility of detecting the anomalous neutrino magnetic moment from comparison of the “electromagnetic” and “electroweak” contributions to the differential and total cross sections of neutrino-electron scattering is considered. The results of quantitative analysis and a graphical image of the cross sections are presented for the case of scattering of beryllium solar neutrinos by an electronic target.     

Analysis of the threshold anomaly in proton elastic scattering on A ∼- 30 mass nuclei

The threshold anomaly in energy-averaged excitation functions of proton elastic scattering on A ∼- 30 mass nuclei is analyzed in the framework of the Lane model for p-wave threshold effects. A quantitative correlation between the strength of the threshold anomaly and the 2p-wave neutron strength function is reported.     

Nonlinear gain and dispersion in the four-level Λ-type system

The nonlinear gain and dispersion spectra of a four-level Λ-type system, which driven by a weak probe field and coupling field, is investigated. Using the perturbation method, third-order perturbation iterative solutions of the steady density matrix equations are obtained. We find that effect of the SGC on the nonlinear gain and dispersion are negligible. At the resonant coupling, nonlinear dispersion spectra of the two transition paths are symmetrical about a line, but the nonlinear absorption spectra are symmetrical about a point. The degeneration of the two lower states greatly modifies the nonlinear gain and dispersion spectra.     

Asymmetry measurement of the polarized Σ+p elastic scattering and the hyperon-nucleon spin-orbit interaction

In order to study the hyperon-nucleon spin-orbit interaction, asymmetries of the polarized Σ⁺ elastic scattering on protons have been measured. The polarized hyperons were produced through the p(π⁺, K⁺) Σ⁺ reaction in a liquid-scintillator active target, and tracks of Σ⁺p scattering events were recorded with a newly developed track detector named SCITIC (scintillating track image camera). Although analyses of 10 times more data with more sophisticated data-taking systems and more elaborated analyzing tools are under way, data from an early stage of this experiment indicate a large Σ⁺p spin-orbit interaction in contrast to the case of the small ΛN spin-orbit interaction. Received: 27 May 2002 / Accepted: 23 July 2002 / Published online: 19 November 2002 RID="a" ID="a"e-mail: nakai@post.kek.jp Communicated by Th. Walcher     

Cross sections and asymmetries for elastic π3He scattering in the energy region around the Δ resonance

For a polarized target, π³He interaction is studied in the fixed-center approximation with all rescatterings included. Only the P ₃₃ wave is taken for the πN interaction. The nuclear wave function is taken either as a sum of Gaussian functions or as a Faddeev wave function in the s-wave approximation. The differential cross sections and asymmetries for elastic π⁺³He scattering at the laboratory energies of T _π, 180, and 256 MeV are calculated. The results are compared with experimental data.     

Calculation of the elastic scattering properties for cold and ultracold 39K atoms in a triplet state

The elastic scattering properties for collisions between cold and ultracold 39K atoms in a triplet state are investigated. Based on the recent theoretical and experimental results, the improved hybrid potential is presented for a triplet α3∑u^＋ ground state of K2. Our calculated value of the s-wave scattering length a by using the Numerov method for the triplet state is 79.578α0 and found to be in good agreement with the previous ones. The numbers of bound states are supported by the molecular potential. Pronounced shape resonances appear for the l = 3 partial waves for the α3∑u^＋ state. Furthermore, the s-wave scattering cross section, the total cross section and energy positions of shape resonances for the α3∑u^＋ state are calculated.     

A potential description of α-particle elastic scattering by the 6Li and 7Li nuclei

The results of analytic and numerical calculations of the real part of the ??⁶Li interaction potential in the cluster folding model are reported. Elastic scattering phases in the ??+^6,7Li systems are calculated and constructed, a classification of multipole transitions for back photodisintegration reactions is given.     

S-ware πN scattering effects in the nuclear three-body force

We examine the contributions of the off-mass-shell,s-wave N scattering amplitude terms in the Tucson-Melbourne two-pion-exchange three-body force to the trion binding energy. While thea andc terms are not as important as thep-wave terms, they comprise a nonnegligible part of the three-nucleon force which produces nonperturbative effects in the triton wave function.     

Electron scattering with the excitation of the 15.11 MeV state of12C and theπ 12B12C coupling constant

Theπ ¹²B¹²C coupling constant is extracted from the data on theM1 form factor of¹²C using the PCAC and CVC hypotheses. The extrapolation of the form factor to the pion pole using analyticity arguments leads to the value \(f_{\pi ^{12} B^{12} C}^2 = 0.052\) . Our present knowledge of this coupling constant is discussed.     

π+p and K+p elastic scattering at 250 GeV/c

Results are presented on π⁺p and K⁺p elastic scattering at 250 GeV/c, the highest momentum so far reached for positive meson beams. The experiment (NA22) was performed with the european hybrid spectrometer. The π⁺p elastic cross section stays constant with energy while the K⁺p cross section increases.     

Measurements of π+p,K+p and pp elastic scattering)

The paper presents the results on differential cross sections for elastic scattering of 7⁺-, K⁺-mesons and protons on protons in the 4-momentum transfer squared range 0·08 ¦t¦ 1·0 (GeV/c)² and incident particle momentum of 29 and 43 GeV/c for pions and kaons and 29, 43, 50 and 65 GeV/c for protons. The measurements were taken with the spectrometer Sigma, installed in the positive beam of the IHEP accelerator.Presented by F. A. Yotch at the Symposium on Hadron-Hadron Scattering at High Energies, Liblice, Czechoslovakia, June 16–21, 1975.The authors would like to express their gratitude to A. A.Logunov, Yu. D.Prokoshkin, L. D.Soloviev and V. A.Yarba for their support of this experiment. We are indebted to CERN Administration for giving us a permission to use a part of equipment of the CIBS spectrometer and to W.Kienzle for useful discussions.     

Extraction of the asymptotic normalization coefficient for the first 2+ level of 16O from the analysis of α12C scattering on the basis of analytical approach

The information about the nuclear vertex constant G ₁₂ for the ¹⁶O(6.917 MeV, 2⁺) ? α + ¹²C vertex and the related asymptotic normalization coefficient C ¹² of the wave function of the first excited state of the ¹⁶O nucleus with the angular momentum J = 2 and positive parity is extracted on the basis of the phase analysis data for the α¹²C scattering using the N/D equations, with allowance for the Coulomb interaction effects.     

On applicability of the Glauber model for pion elastic scattering by helium in the δ33 resonance region

Elastic scattering of pions by³He and⁴He in the region of the first pion-nucleon resonance is calculated within the Glauber theory. The spin-flip and charge-exchange effects are fully taken into account. Calculated results are compared with experiment and with predictions obtained using the optical model. Some conclusions are drawn concerning the validity of approximations used in deriving the two models. The calculations make clearer some of the limitations of using the Glauber model for very low energies.On leave fromInstitute of Nuclear Physics, e — Prague, Czechoslovakia.     

Electron-atomic-hydrogen “elastic" scattering in the presence of a laser field

Laser-assisted electron-atomic-hydrogen “elastic" scattering is studied in the first Born approximation. The initial and final states of projectile electron are described by the Volkov wavefunctions; the dressed state of target described by a time-dependent perturbative wavefunction in soft photon approximation. The laser modified cross-sections are calculated in two distinct geometries for laser polarization either parallel or perpendicular to the incident direction of electron. The numerical results shows that the multiphoton cross-sections oscillate by a few orders over the whole scattering angular region. The results for a parallel geometry oscillate more frequently in the intermediate angles; while the results for a perpendicular geometry oscillate more frequently in the forward and backward angles. At large scattering angles, the sum rule of Kroll and Watson is noticeably violated. The laser modification on summed total cross-section increases with field strength, but decreases with field frequency and polarization deviation from the incident direction. Received 18 October 2001 and Received in final form 26 December 2001     

Breathers and solitons for the coupled nonlinear Schr?dinger system in three-spine α-helical protein

We mainly investigate the variable-coefficient 3-coupled nonlinear Schr?dinger(NLS) system, which describes soliton dynamics in the three-spine α-helical protein with inhomogeneous effect. The variable-coefficient NLS equation is transformed into the constant coefficient NLS equation by similarity transformation firstly. The Hirota method is used to solve the constant coefficient NLS equation, and then we get the one-and two-breather solutions of the variable-coefficient NLS equation. The results show that, in the background of plane waves and periodic waves, the breather can be transformed into some forms of combined soliton solutions. The influence of different parameters on the soliton solution and the collision between two solitons are discussed by some graphs in detail. Our results are helpful to study the soliton dynamics inα-helical protein.     

Study on the optical system for the record of the pulsed acoustic field and the scattering of the cylindrical-like objects buried in underwater sand

11尬roductlon For the vlsuallzatlon and the studies of the physical properties of acoustic ield;the schlierentechnique was the most useful for the co尬Inuous waves[1,2].ReceNwars,the shadowgraphmode was appeared for the recording of＊theing acoustic pulse[3-p].Although the shadowgr地hmode Is used more frequently In experimental fluid dynamics[6],In the irst part of this paper;the response of＊these opticall扯enslty of＊the recorded acoustic pulse related to the acousticpressure gradlem Is st…