INVESTIGATION OF THE EFFECT OF NUCLEAR SHORT RANGE CORRELATION IN HEAVY ION SCATTERING

Bassed on the "Rigid Projectile" approximation and the Glauber's multiple scattering theory. The influence of the nuclear short range correlation on elastic scattering of high energy heavy ion is discussed. The elastic α-¹²C scattering at 1.37 GeV is calculated and compared with experimential data. It is show that the influence of the unclear short range correlation on differential cross section is quite important.     

STUDY OF ANOMALOUS LARGE ANGLE α-SCATTERING ON 24Mg

Angular distribution for the elastic and some inelstic scattering of α particle on²⁴Mg isotope between 12°and 178°in steps of 2°(Lab) have been measured at 18.1MeV α bombarding energy. α+²⁴Mg elastic scattering angular distribution at back-ward angles displays more pronounced oscillation and a strong overall rise of crosssection. The calculation by the standard optical model together with compound nuclearscattering (via H-F) cannot predict this anomalous enhancement. The calculation byuse of an L-dependent imaginary potential optical model is in good agreement withthe experimental data. The fits of L-dependent optical model to the experimentalangular distributions of other energies are also discussed.     

ELASTIC AND INELASTIC π-NUCLEAR SCATTERING

Using Glauber theory,the π-¹²C elastic and inelastic scattering differential cross-sections at the energies 260 and 280 MeV are calculated and analyzed.Comparing withthe experimental data,better fits are obtained.     

U(6/20) SUPERSYMMETRY IN NUCLEI AND ITS Spin (6) LIMIT

The U(6/20) supersymmetry is discussed in this paper. Particularly we discuss its Spin (6) limit. First we discuss the reduction of the group chain of the Spin(6) limit. Secondly we derive the wave functions and excited energy formulas for the nuclei in which the Spin(6) limit of U(6/20) supersymmetry exists. Thirdly we make comparison of the nuclear energy spectra between the theoretical calculation and experimental measurement in the case of nucleus ₇₇¹⁹³Ir₁₁₆. The comparison shows that the Spin(6) limit of U(6/20) supersymmetry possibly exists in nucleus ₇₇¹⁹³Ir₁₁₆.     

A SEMI-CLASSICAL ANALYSIS ON THE REACTION 12C+209Bi AT BOMBARDING ENERGIES SLIGHTLY ABOVE THE COULOMB BARRIER

For reactions induced by light heavy ion such as ¹²C, at bombarding energy slightly above the coulomb barrier, using semi-classical theory, neglecting macroscopic frictional force, the reaction mechnisms are sorted by the orbital angular momentum of the entrance channel from the classical deflection functions fitting elastic scattering. Moreover, inserting a transfer probability factor representing the Q-Window effect into the semi-classical angular distribution formula of Kalinkin and Grabowski, we obtain a formula for the differential cross-section per unit energy interval. The calculated results, including the elastic scattering angular distributions, energy spectrum and angular distributions of emitted α-particles in quasi-elastic process, complete fusion cross-section, fusion-fission cross-sections and the exitation functions of evaporated neutron, agree with the experimental data on the reaction ¹²C+²⁰⁹Bi reported by our Institute.     

MICROSCOPIC CALCULATION OF THE INERTIA IN HEAVY NUCLEI

A realistic calculation of the inertia for ²³⁶U fisson based on the linear response theory is presented, in which the single particle states are provided by Nilsson model. The dependence of the nuclear inertia M_δiδi on the collective variables δ₂, δ₄ is studied at the range of certain nuclear temperature (0—1 MeV). The pairing effect and the shell effect on the nuclear inertia are discussed. The calculated results show a very prominent structure at level crossing points and when acrossing the critical temperature.     

EFFECT OF N PRODUCTION ON HIGH ENERGY PROTON SCATTERING BY NUCLEUS

The variable separation method of Glauber multiple scattering theory is developedto include the N^* production in the intermediate states and is used to calculate theinelastic scattering of proton by nucleus.Numerical results are compared with dataon p-¹²C^*（4⁺,14.08）at 1 GeV and it implies that the effects of N^* production tothe high-energy proton-nucleus scattering are noticeable.     

THE EFFECTS INDUCED BY A Λ HYPERON ON THE PAIRING CORRELATION IN NUCLEUS

In this paper, the effects induced by a Λ hyperon on the pairing correlation in nucleus are investigated. For simplicity, the δ-type A-N residual interaction is adopted. We have calculated the energy Spectrum and wave function of the low-lying excited states for _Λ¹⁰O. Then using infinite sum approximation, the correlation effect for two nucleons in the high energy shell induced by a Λ-hyperon is discussed.Finally. by means of Bose approximation, the correlation effects for n pairs of nucleons induced by a Λ is analysed.     

THE INFRARED STRUCTURE AND THE ELECTROMAGNETIC FORM FACTORS OF QUANTUM CHROMODYNAMICS IN TWO DIMENSIONS

We discuss a model of quantum chromodynamics in 1+1 dimension.Using't Hooft's 1/N expansion and considering the effects of the infrared structure in non-Abelian gauge theories by assuming that the coupling g²（t）～1/t^κ-1,the Straton's Pro-pagator and the Bethe-Salpeter equation of mesons are obtained;the propertiesof the meson wave functions and their characteristics are also discussed.From thebehaviour of the electromagnetic form factors and the deep inelastic scattering struc-ture functions obtained,it follows that κ≤2.     

A TWO-NUCLEON MODEL OF THE（p,π-） REACTION

In this paper,we suggest a two-nucleon model of the A（p,π^-） B reaction.Areduced formulation of the reactoin amplitude and a relation between the reactionamplitude and the nuclear structure are given.The differential cross section of ¹³C（p,π^-）¹⁴O_g.s,at E_P=185 MeV is calculated in the plane wave approximation.The results+s can explain the experimental data qualilatively.     

ON THE “DIRECT CHANNEL DIAGRAM” OF THE PRODUCTION OF THE （π+ π-）s S-STATE ATOMS

In this paper we work out the relativistic covariant B-S wave function for the（π⁺ π^-）_s atoms.Some properties of the“direct channel diagram”of the produc-tion the （π⁺ π^-）_s atoms are discussed by calculating the cross-section of the process π⁺ +n→p+（π⁺ π^-）_s with the help of the relativistic covariant wave function and assuming the lowest termin the perturbation expansion series of the quantized composite field theory——the“direct channel diagram”is dominant.Besides this calcuation perhaps presentsa rough estimate for the interesting process μ⁺ +n→（μ⁺ π^-）+p.     

Exotic Behavior of Elastic Scattering Differential Cross-Sections of Weakly Bound Nucleus 17F at Small Angles

The differential cross-sections for elastic scattering of ¹⁷F and ¹⁷O on ²⁰⁸Pb have been measured at Radioactive Ion Beam Line at Lanzhou (RIBLL). The variation of the logarithms of differential cross-sections with the square of scattering angles shows clearly that there exists a turning point in the range of small scattering angles (6°—20°) for ¹⁷F having exotic structure, while no turning point was observed in the ¹⁷O elastic scattering. The experimental results have been compared with previous data. Systematical analysis on the available data seems to conclude that there is an exotic behavior of elastic scattering differential cross-sections of weakly bound nuclei with halo or skin structure as compared with that of the ordinary nuclei near stable line. Therefore the fact that the turning point of the logarithms of differential cross-sections appears at small angle for weakly bound nuclei could be used as a new probe to investigate the halo and skin phenomenon.     

PION SCATTERING FROM WELL-DIFORMED NUCLEI

In the framework of the eikonal theory and using the first order π-nucleus optical potential, the elastic and inelastic scatterings of π^± from well-deformed nuclei are discussed. The virtual excitations to the low-lying levels are taken into account in the calculations of the elastic scatterings by using the closure approximation. The theoretical results of pion scatterings from ¹⁵²Sm at T_π=180MeV are compared with the data.     

EXCITATION FUNCTION FOR ELASTIC COLLISION BETWEEN 4n NUCLEI

Resonant structures appeared in the excitation functions for the ¹⁶O+²⁰Ne elastic scattering have been studied by using the nuclear molecular orbital theory.The theoretical results agree well with the experimental data.     

NUCLEUS-NUCLEUS INELASTIC SCATTERING AND THE INFLUENCE OF PROJECTILE NUCLEI STRUCTURE AT HIGH ENERGIES

On the base of Glauber's theory, nuclei-nuclei inelastic scattering amplitudes are given by using the rigid projectile approximation. Inelastic scattering differential cross sections of α+C¹² at 1.37GeV with 2⁺(4.43MeV) and 3^－(9.64MeV) of C¹² in the final state are calculated. The influence of the different density distributions of the projectile nuclei on nuclei-nuclei inelastic scattering is discussed.     

MEASURMENT OF PROJECTILE-LIKE FRAGMENTS PRODUCED BY 80.6MeV16O ON 27Al

The projectile-like fragments produced by 80.6MeV ¹⁶O on ²⁷Al were measured using the large area position sensitive ionization chamber. The energy spectra, angular distributions, contour plots of d²σ/dΩdE in the E-θ plane of the reaction products from Li to Na and the Z-distribution were obtained. The cross sections of the quasi and deep inelastic scattering were introduced. A brief discussion of the experimental results is also given.     

π-NUCLEAR DOUBLE CHARGE EXCHANGE REACTION AND NUCLEAR STRUCTURE

Using Glauber's multiple scattering theory, and using coherent fluctuation nuclearmodel, the double charge exchange (DEC) reaction cross sections for πon ¹⁶O and ¹⁸Ohave been calculated. The calculated values of the ratio of σ(¹⁸O(π⁺,π^-)¹⁸Ne)_g.s. toσ(¹⁶O(π⁺,π^-)¹⁶Ne)_g.s. fit the experimental data quite well. Just as predicted by ourcalculation, the angular distribution of ¹⁸O(π⁺,π^-)¹⁸Ne_g.s. in a recent experiment,exhibits an evident dip around 23°.     

Treatment of Coulomb Interaction in Momentum Space for p-3He Elastic Scattering

Applying the method proposed by R.Crespo and J.A.Tostevin to p-³He elastic scattering,we study the treatment of Coulomb interaction of momentum space.The differential cross sections and spin observables at 500 and 300 MeV are calculated with R=7fm.The present results are compared with those given in V-P method.It shows that the applicable range of angular momentum and momentum transfer in R-J method are wider than those in V-P method.     

INTERACTING BOSON MODEL FOR EVEN-EVEN NUCLEI POSSESSED OF 1+ AND 3+ BANDS IN THE ROTATIONAL RIGION

On the bases of s, d IBM, octupole states are taken into account and the two-quasiparticle excitation is treated as boson-like in the SU(3) limit. The energy spectra are obtained analytically and the nondegenerated 1⁺ and 3⁺ bands are also reproduced. The calculated spectra of eight nuclei, which possess with 1⁺ or 3⁺ bands in their energy spectra in the rotational rigion, agree with the experimental ones fairly good.