MULTIPLICITY DISTRIBUTIONS OF PRODUCED PARTICLES IN α-α COLLISIONS AT HIGH ENERGIES

We analyse the multiplicity distributions of negative particles produced in α-α collisions at S_NN=31.2GeV by using a Glauber-type multiple collision model in which the projectile nucleons degrade in energy as they make collisions with target nucleons.The energy loss suffered by the projectile nucleons in the passage through the target nucleus is explicitly considered in the calculation.The agreement with experiments is good.     

POWER EMISSION OF A MONOPOLE IN REVERBERATION CHAMBERS

An exact sound power emission formula of a simple source in a reverberation chamber is derived fromnormal mode theory as a function of its position in the room,and important properties of the emission arefound from simple analyses.For example,the average emission of the source in the room is not equal to thefree space emission but greater,on the contrary to the common notion.A smooth statistical formula is alsoderived for the variation of average sound power in an axial direction,which holds even at low frequency atwhich the wave length approaches the mean free path in the room.The sound power is found to havenumerous peaks in the room forming a three-dimensional lattice structure with high power barriers aroundthe boundary walls.The space factor in an axial direction is essentially exact,but the general formula of poweremission formed with the product of space factors in three axial directions might have some error.Numericalexamples are presented to check this.The variability of sound power emission in     

COLLISIONS OF HIGH—RYDBERG ATOMS IN CIRCULAR STATES WITH RARE-GAS ATOMS

Collisional state mixing of high-Rydberg atoms in the(nlm)states hasbeen the target of active theoretical and experimental research.Here nis the principal quantum number,l is the angular momentum and m is the     

DOUBLE Ф-MESON PRODUCTION IN HADRONIC COLLISIONS

The longitudinal and transverse momenta distributions of Ф-meson in πp and pp collisions are calculated in Q²Q² picture. The longitudinal momentum distribution of Ф-meson is consistent with expecimental data.     

CHARGE CHANGING PROCESSES IN ION—ATOM COLLISIONS

When an ion A~(q ) traverses in a gaseous target B,the charge of theion q is changed by collisions with the atom B as A~(q ) B→A~((q-p) ) B~(p ) (1)     

COINCIDENCE MEASUREMENT BETWEEN α-PARTICLES AND PROJECTILE-LIKE FRAGMENTS IN REACTION OF 82.7MeV 16O ON 27Al

In the coincidence measurement between α-particles and projectile-like fragments in the reaction of 82.7MeV ¹⁶O on ²⁷Al,the contour plot of the C-α coincidence in the velocity plane and the coincident angular correlation are obtained. Different mechanisms of α-particle emission are analysed. A possible reaction mechanism of incomplete DIC is descussed.     

RESEARCH AND TECHNICAL NOTES ULTRASONIC ATTENUATION IN α-LiIO_3 SINGLE CRYSTAL AT LOW TEMPERATURES

Ultrasonic attenuation in an α-LiIO_3 single crystal has been measured in the [001],[010] and[100] directions at low temperatures by using the standard pulse echo method.It is clear thatultrasonic attenuation anisotropy exists in α-LiIO_3 above 273 K and disappears below 273 K.     

THE REFLECTION AND REFRACTION OF A LARGE AMPLITUDE PLANE SOUND WAVE IN TWO DIMENSIONS

By using the successive approximation method,a wave equation,in which the second order ofapproximation is taken into account,has been derived from the basic equations of hydrodynamicsin Lagrangian coordinates.The reflection and refraction of a large amplitude plane sound waveon the plane interface of two non-mixing liquids are studied.It is interesting to point out that thereflection and refraction coefficients of second approximation not only depend on parameters ofmedia,but also relate to the position of sound source.It is found that the amplitudes of the secondorder reflected wave and refracted wave do not keep constant at the wavefront anymore as inlinear acoustics.Hence there are reflected wave and refracted wave which propagate in the directionother than that of waves,travelling along the directions defined by laws of reflection and refractionin linear acoustics.The nonlinear effects have to be taken into account in order to understand thephysical meaning of the results reported by Muir et al..     

THE BOUND STATE ENERGY LEVELS OF MONOPOLE PAIR AND OF CHARGED MONOPOLE-ELECTRON SYSTEM—SOME SINGULAR STATE PROBLEMS IN RELATIVISTIC QUANTUM MECHANICS

In this paper four kinds of singular state problems in relativistic quantum me-chanics and its solutions are summarized. In the references [2,3,5,6,11], it hasbeen pointed out that in some quantum mechanial problems involving singular statesthere exists phase angle uncertainty. The principle eliminating this kind of nncer-tainty——the orthogonality-variation principle has been obtained in [11] The re-sults of scattering and bound state problems of a neutral monopole and a chargedDirac particle are consistent with those obtained by C. N. Yang, Kazama, and Gold-haber. In [5], [11] and this paper the Case-type equations determining the boundstates of monopole pair and exotic atoms consisting of a charged monopole and anelectron are obtained. In this paper these energy levels are calculated numericallyBecause in these equations the number of singular points is infinite and the rune-tions oscillate rapidly, usual calculation methods are not suitable in these cases. Afteranalysing these equations and determining the positions of singular points and theranges of energy levels, these energy levels are calculated by computer. It is pointed out that the number of these energy levels is infinite and the posi-tions of positive and negative energy levels are asymmetric. The negative energylevels do not appear untilεis very near -1. The values of the positive energy levelsare spread in the range 0.9998ε<1 They are near those of the hydrogen-like atomand similar to those of impurity in solid. This is a perturbation problem of singularstates to which the usual perturbation theory can not be applied. The energy levels of monopole pair are not similar to those of the hydrogen-likeatom. In the range 0<|ε|≤0.99 there are many energy levels with positive andnegative energy. It is also pointed out that for the hydrogen-like atoms, 119<z<137, somenegative energy bound state solutions satisfying square integrability condition arepossible. The ordinary standard condition does not exclude these states, but the or-thogonality criterion does exclude them. The conclusion is in agreement with thatreached by Professor C. N. Yang. The results shown suggest that the orthogonality-variation principle is reasona-ble.     

INTERACTION FREE PATH AND PROJECTILE α-FRAGMENT MULTIPLICITY DISTRIBUTIONS IN 84Kr-EMULSION COLLISIONS AT 1.4A GeV

The preliminary data of the interaction free path distribution and the multiplicity distribution of projectile α-fragments in Kr-emulsion collisions at 1.4A GeV are presented.     

A RELATIVISTIC EQUATION OF MOTION FOR MANY-BODY SYSTEM(Ⅱ)

A relativistic equation of motion for many-body system is established. The relativistic potential is a certain rearrangement of the irreducible series of many-body B-S equation. Considering the two-body irreducible B-S kernels only the many-body potential is expressed as a sum of two-body ones.     

COLLISIONS BETWEEN HYDROGEN MOLECULAR IONS AND NITROGEN MOLECULES IN eV ENERGY RANGE

The reaction rate coefficient for collision between hydrogenmolecular ions and nitrogen molecules has been measured by usingion storage technique.The results are k_(pt)=5.23×10~(-9)cm~3/sec forproton transfer and K_(et)=4.5×10~(-10)cm~3/sec for charge transfer.     

EXPERIMENTAL STUDY OF EXCITATION AND IONIZATION CROSS SECTIONS OF ATOMS AND MOLECULES BY ELECTRON COLLISIONS

About ten groups over universities and institutes are engaged in thevariety of experimental studies on electron-atom and electron-moleculecollisions in Japan.From works by these groups,two different topics,     

A STATISTICAL THEORY FOR THE BIO-PHOTON EMISSION OF THE LIVING SYSTEMS

ＡＳＴＡＴＩＳＴＩＣＡＬＴＨＥＯＲＹＦＯＲＴＨＥＢＩＯ－ＰＨＯＴＯＮＥＭＩＳＳＩＯＮＯＦＴＨＥＬＩＶＩＮＧＳＹＳＴＥＭＳＰａｎｇＸｉａｏｆｅｎｇＩｎｔｅｒｎａｔｉｏｎａｌＣｅｎｔｒｅｆｏｒＭａｔｅｒｉａｌＰｈｙｓｉｃｓ，ＡｃａｄｅｍｉａＳｉｎｉｃａＤ...     

RECURRENT FORMULA FOR α-ROW PARTITION AND THE CALCULATIONS OF THE MULTIPLICITIES OF COUPLING STATES IN SHELL-MODEL

In this paper, a recurrent formula for α-row partition is given. Using this formula, we get the multiplicities of all sorts of coupling states in shell-model. It has been proved to be very efficient in simplifying the ealculations concerned.     

FORMATION AND EMISSION OF LIGHT PARTICLES IN FAST NEUTRON INDUCED REACTION——A UNIFIED COMPOUND PRE-EQUILIBRIUM MODEL(2)

For fast neutron-induced reactions for structural"materials by using the unified compound pre-equilibrium model, the light composite particles emissions have to be oaken into account properly. The mechanism of cluster fororation and emission was investigated. Estimated results with considering the secondary emission process were compared with experimental data.     

EFFECTIVE POTENTIAL OF λφ41+3 AT ZERO AND FINITE TEMPERATURES

The effective potential of $\lambda$$\varphi$⁴₁₊₃ model with both signs of parameter m² is evaluated at T=0 by means of a simple but effective method for regularization and renormalization. Then at T≠0, the effective potential is evaluated in imaginary time Green function approach, using the Plana formula. A critical temperature for restoration of symmetry breaking in the standard model of particle physics is estimated to be T_c≌510 GeV.     

FORMULAE OF SOUND FIELD IN ENCLOSURES

It is considered necessary that an additional term representing the direct sound be introduced into theclassical normal mode solution of sound field in enclosures,to accord with practice and to make the formu-la more useful.     

TODA–HEISENBERG CHAIN: INTERACTING σ-FIELDS IN TWO DIMENSIONS

We study a (2 + 1)-dimensional system that can be viewed as an infinite number of O(3) σ-fields coupled by a nearest-neighbour Heisenberg-like interaction. We reduce the field equations of this model to an integrable system that is closely related to the two-dimensional relativistic Toda chain and the Ablowitz–Ladik equations. Using this reduction we obtain the dark-soliton solutions of our model.