Can We See SPT Interactions in Coherent Pion Production?

The possibility to detect nonconventional scalar, pseudoscalar or tensor interactions (SPT) in the angular distribution of pions produced coherently in neutrino nucleus reactions is reexamined. It is found that the angular distribution does not differ qualitatively from a corresponding distribution arising from conventional VA interactions unless the energy of the outgoing pion is restricted. Even then SPT interactions are likely to be overshadowed by transverse VA interactions which can mimic the former at finite although small momentum transfer Q².     

Pion and σ-meson Properties in a Strong Magnetic Field

With the Nambu-Jona-Lasinio (NJL) model we calculate the properties of pion and σ-meson at finite temperature and finite magnetic field. The obtained temperature and magnetic field strength dependence of the constituent quark mass M, the pion and σ-meson masses and the neutral pion decay constant indicates that, in the simple four fermion interaction model, there exists the magnetic catalysis effect. It also shows that the Gell-Mann-Oakes-Renner relation is violated obviously with the increasing of the temperature, and the effect of the magnetic field becomes pronounced only around the critical temperature. The deviation of the critical temperatures obtained with different criteria indicates that the chiral phase transition driven by the temperature in the magnetic field strength region we have considered is in fact a crossover.     

Weinberg Angle and Pion Beta Decay in the Spinor Strong Interaction Theory

From an isospin SU(2) × hypercharge U(1)gauge-invariant meson action for K⁺,^{+ +}, a prediction ofthe Cabbibo angle was obtained earlier. Using anotherresult of the spinor strong interaction theory that the s quark is only a littleheavier than the d quark, the above action can beextended to a weakly broken SU(3) one. The Weinbergangle is found to be 30° in the limit of this SU(3)symmetry. In the approximation and context entailing thislimit, the Weinberg angle can be removed from the listof undetermined fundamental parameters in electroweaktheory. The spinor strong interaction Lagrangian used above and applied to the decay⁺ e⁺ is shown tohold for ^{+ 0}e⁺ as well, renderingthe conserved vector current hypothesis hithertorequired to account for the latter decaysuperfluous.     

Strong Interactions in Strange Exotic Atoms

Strong interaction level shifts and widths in ^- and K^- atoms have been analyzed. The phenomenological density dependent approach as well as the relativistic mean field (RMF) model yield nucleus optical potentials with a repulsive real part in the nuclear interior. This has important consequences for the spectroscopy of hypernuclei. The study of K^- atoms cannot resolve the depth of the K^- nucleus potential. The fits to the kaonic atom data are satisfactory for both the relatively shallow potentials derived from chiral models and for the deep potentials based on the phenomenological and RMF analyses.     

Bremsstrahlung neutrino energy loss for ^24Mg, ^28Si, ^32S, ^40Ca, ^56Fe in strong electron screening

Based on Weinberg-Salam theory the bremsstrahlung neutrino energy loss for nuclei ^24Mg, ^28Si,^32S, ^40Ca and ^56Fe are investigated in strong electron screening. Our results are compared with those of Dicus＇ and show that the latter are higher by 2 orders of magnitude in the density-temperature region of 10^8 g/cm^3 ≤p/μe ≤ 10^11 g/cm^3 and 2.5≤ T9≤ 4.5. On the other hand, the factor C shows that the maximum differences are 99.16%, 99.13%, 99.12%, 99.055%, 99.040% corresponding to the nuclei ^24Mg, ^28Si, ^32S, ^40Ca and ^56Fe.     

超高能核作用中的晕事例

观测能量大于10¹⁵eV的γ族事例,在乳胶室中往往形成晕,给进一步观测超高能核作用的特征带来许多不便.目前只能给出一些粗糙的量来描述晕事例.然而晕事例的内部还有精细的结构,能提供更多的信息.作者对超高能族事例尽可能作逐个簇射测量,并用测量晕的方法进行重复测量,进行比较.并就某些特例作了分析与讨论.     

Spin Physics and the Theory of Strong Interactions

Taking the Minkowski space as the scene of quantum field theory implies an implicit assumption: the spin plays no dynamical role. This assumption (already challenged by reggeism) should be re-examined in the light of recent advances of experimental spin physics. To make a dynamical role of spin possible, it is proposed to use as a scene for the theory of strong interactions the whole Poincaré group. On the other hand characteristic functions, defined on the Poincare group, provide the only known way to describe the distinctive peculiarity of resonances, namely that a resonance is both one particle and several particles. Regge trajectories are interpreted as evidence for a mass-spin correlation among the virtual hadrons of vacuum. It is conjectured that the form of this correlation is deducible from a central limit theorem on the Poincare group. And that a statistical mechanics of hadronic vacuum is important for strong interaction theory.     

Jet-Like Long Spike in Nonlinear Evolution of Ablative Rayleigh–Taylor Instability

We report the formation of jet-like long spike in the nonlinear evolution of the ablative Rayleigh-Taylor instability （ARTI） experiments by numerical simulations. A preheating model k（T） = KSH[1＋f（T）], where KSH is the Spitzer Harm （SH） electron conductivity and f（T） interprets the preheating tongue effect in the cold plasma ahead of the ablative front [Phys. Rev. E 65 （2002） 57401], is introduced in simulations. The simulation results of the nonlinear evolution of the ARTI are in general agreement with the experiment results. It is found that two factors, i.e., the suppressing of ablative Kelvin Helmholtz instability （AKHI） and the heat flow cone in the spike tips, contribute to the formation of jet-like long spike in the nonlinear evolution of the ARTI.     

Effect of Strong Electron-Phonon Interactions on an Interface Polaron

The present work deals with an electron interacting strongly with both bulk longitudinal optical (LO) phonons and interface (IF) optical phonons in which we adopt and generalize the Tokuda's variational method for studying the interface polaron properties in polar crystals at zero temperature, In our approach, we can reduce the Hamiltollian equation of the system to a pair of integro-differential equations in two variational parameters of the electron wavefunction from which we can calculate various physical properties of an interface polaron including the ground state energy, average numbers of interacting phonons, the average distance from the interface and the anisotropic effective masses of the interface polaron. Numerical results are obtained explicitly for LiF crystal interfaced with NaF crystal as well as other similar systems with varying physical constants, which show the typical trends of variations for the effects of strong electron-phonon interactions on different physical properties of an interface polaron.     

Formation of the Heavy Isotope $${}^{\boldsymbol{6}}$$ He upon Stopped Pion Absorption by Nuclei

Physics of Atomic Nuclei - A survey of experimental results on the level structure in the heavy helium isotope $${}^{6}$$ He that were obtained in reactions induced by stopped pion absorption in...     

Electromagnetically Induced Transparency in a Cold Gas with Strong Atomic Interactions

Electromagnetically induced transparency(EIT) is investigated in a system of cold,interacting cesium Rydberg atoms.The utilized cesium levels 6S_(1/2),6P_(3/2) and nD_(5/2) constitute a cascade three-level system,in which a coupling laser drives the Rydberg transition,and a probe laser detects the EIT signal on the 65_(1/2) to 6P_(3/2)transition.Rydberg EIT spectra are found to depend on the strong interaction between the Rydberg atoms.Diminished EIT transparency is obtained when the Rabi frequency of the probe laser is increased,whereas the corresponding linewidth remains unchanged.To model the system with a three-level Lindblad equation,we introduce a Rydberg-level dephasing rate γ_3=κ x(ρ_(33)/ Ω_p)~2,with a value κ that depends on the ground-state atom density and the Rydberg level.The simulation results are largely consistent with the measurements.The experiments,in which the principal quantum number is varied between 30 and 43,demonstrate that the EIT reduction observed at large Ω_p is due to the strong interactions between the Rydberg atoms.     

Strong Self-Similar Fluctuations of Target Fragments in Ring-like Events in Ultra-Relativistic Nuclear Collision

The intermittent fluctuation of target evaporated particles is studied in both ring-like and jet-like events emitted in ^32 S-emulsion interactions at 200 A Ge V within the framework of multi-dimensional factorial moment methodology using the concept of the Hurst exponent. It is observed that the intermittent fluctuation in the ring-like event is self-similar, whereas in the jet-like event fluctuation is self-affine. However, study indicates that the strength of fluctuation in the ring-like events is much stronger than that in the jet-like events.     

Fluctuation kinetics of diffusion-controlled processes: Strong effects due to correlations and fluctuations

We summarize some recent results related to fluctuation-induced kinetics of diffusion-controlled processes. We show that kinetic behavior can be drastically changed due to fluctuation effects, spatial correlations between particles, and anomalous transport properties. In addition, we show that correlation-induced kinetics in some systems can govern the temporal evolution over the entire time domain.     

Observation of Three-Quasiparticle Doublet Bands in ^123I： Possible Evidence of Chirality

A new band in the odd proton nucleus ^123I is identified via in-beam γ-ray spectroscopy using the ^14N＋^116Cd reaction. This band shows up as doublets with the previously assigned π97/2 （vh11/2）^2 band. Possible configurations of the new band are discussed in the framework of the cranked shell model and the geometrical model It is argued that the new band might be a chiral partner of the previously known πg9/2 （vh11/2）2 band.     

Limiting Fragmentation Behaviours of Correlation and Fluctuation of Particle Produced in High Energy Oxygen-Nucleus Induced Interactions

The limiting fragmentation behaviour of the single-particle pseudo-rapidity distributions and the two-particle correlations in oxygen-nucleus induced interactions in the energy region from 3.7 to 200A GeV is systematically investigated,and that of the dynamical fluctuations of multi-particle distribution is studied by using the relation between the factorial-moments and the multi-particle pseudo-rapidity distributions.