Infrared Spectrum of Dihydridobis(ethylenediamine) Osmium Tetrachloro Zincate

The ethylenediamine trmsition metal complexes^1-9 of the type M(en)₂X₂ (M = Co, Ni, Cu, Pd, Pt and × = I, Br, C1, NO³, C10⁴) have infrared spectra of complicated nature which have been used for the study of conformation of the chelate ring. In dihydrldobis ZnC14 ethylenediamlne transition metal complexes, the hydrogen bonding and the presence of ZnCl₄ further complicates the vibrational spectra. With a view to study this, the present study of dihydridobis (ethylenedianlne) osnlum tetrachloro zincate was carried out.     

不变振幅的不同投影选择对核子自能与碰撞截面的影响

本文利用Dirac-Brueckner-Hartree-Fock方法,对不同散射道的核子在核物质中的相互作用进行了细致分析,重点分析了不变振幅的不同投影选择对核物质中核子自能和核子碰撞截面的影响.计算结果显示:1)在确定的核子动量下,自旋三重态所对应的自能总是大于自旋单态的自能;同位旋三重态所对应的自能大于同位旋单态的自能值.2)在完全赝矢(CPV)选择下,不同散射道的核子自能对于动量的依赖均明显弱于在赝标(PS)选择下的相应值,而这种差别主要来自于总角动量J较小的分波态.3)在核子相对动量较小时,两种不同选择所对应的核子微分截面较大.4)在确定的入射能量下,质心系中散射角较小时,不同选择下的微分截面差别较为明显.5)在低入射能区,CPV选择下所对应的微分截面大于PS下的微分截面值.6)在CPV选择下的总截面总是大于PS选择下的总截面值.这些差别均随着随入射能量的增大而消失.     

Improved Light-Cone QCD Sum Rule Analysis of Rare Decays Λb → Λγ and Λb → Λl+l-

We present a systematic light-cone QCD sum rule study of the exclusive rare radiative decay Λ_b → Λ_γ and rare semileptonic decay Λ_b → Λl⁺l^- within the framework of the standard model. Although some light-cone sum rule (LCSR) studies on these rare processes can be found in different literatures, it is necessary to reanalyze them systematically for the reason that either the baryonic distribution amplitudes are improved or different interpolating currents for the Λ_b baryon may lead to quite different results. In addition, the rare process Λ_b → Λ_γ has not yet been analyzed by LCSR with the Ioffe-type current. Taking all these reasons into account, we perform LCSR calculations of both the processes with two types of interpolating currents. Our calculations show that the choice of the interpolating current for the Λ_b baryon can affect the predictions significantly, especially for the rare radiative decay process.     

松弛时间对热弹性扩散板中环形峰波的影响

在不同热弹性扩散理论的框架中,无应力作用、恒温/绝热、化学势条件下,研究了均匀、横观各向同性无穷板中热弹性扩散环形峰波的传播．得到了热弹性扩散Lamb型波的色散方程．同时推演出色散方程的一些特例．     

Do Dyson Orbitals resemble canonical Hartree–Fock orbitals?

ABSTRACT

Dyson orbitals are overlaps between states with N and N±1 electrons and provide conceptual links between transition probabilities of electron detachment or attachment, density matrices, total energies and general principles of chemical bonding. Canonical, Hartree–Fock orbitals are compared with Dyson orbitals obtained with electron–propagator calculations that retain all elements of the self–energy matrix, wherein all orbital–relaxation and electron–correlation corrections to Koopmans results reside. For valence ionization energies and electron affinities of representative closed–shell molecules, canonical, Hartree–Fock orbitals usually are excellent approximations to Dyson orbitals, although there are some notable cases where the resemblance is not as strong. Numerical relationships between pole strengths and the Koopmans contributions to Dyson orbitals also are inferred from the data.     

Infrared safe observables in super Yang–Mills theory

The infrared structure of MHV gluon amplitudes in planar limit for super Yang–Mills theory is considered in the next-to-leading order of PT. Explicit cancellation of the infrared divergencies in properly defined cross-sections is demonstrated. The remaining finite parts for some inclusive differential cross-sections in planar limit are calculated analytically. In general, contrary to the virtual corrections, they do not reveal any simple structure.     

Shape Coexistence in 74Se

The 0 _1,2 ⁺ ,2 _1,2 ⁺ and 4 _1,2 ⁺ states in ⁷⁴Se have been described as linear combinations of pure states with definite deformation within a two-band mixing model. The mixing amplitudes between the spherical and deformed configurations and the mixing matrix elements have then been extracted from the calculations. The exchanged position between the spherical and deformed configurations at I=4 has been obtained within this model.     

Phase shift analysis of hyperon-nucleon elastic scattering using optimized polynomial expansion techniques

A relatively stable method of phase shift analysis of hyperon-nucleon scattering proposed by us is applied to Σ⁺ p and Λp scattering. The analytic cutt-planes of analyticity of the helicity amplitudes are mapped into the interior of unifocal ellipses. The helicity amplitudes are then expressed as accelerated convergent expansions in the mapped variable. A definite economy is observed in the number of free parameters for fixed energy phase shift analysis of Σ⁺ p and Λp scattering at 40 and 100 MeV and 100 MeV respectively. Twenty six more phase shifts and coupling parameters corresponding to higherJ values are also predicted.     

Glauber amplitudes for transitions from low lying states in hydrogen atom by charged particle impact

The Glauber amplitudes for the general transitionnlm→n’l’m’ in charged particle hydrogen atom collisions have been obtained in the form of a one-dimensional integral. The final expression involves only a few hypergeometric functions ifn is not too large and is particularly suited to study excitation to highly excited states from a low lying state.     

Statistics of Persistent Events in the Binomial Random Walk: Will the Drunken Sailor Hit the Sober Man?

The statistics of persistent events, recently introduced in the context of phase ordering dynamics, is investigated in the case of the one-dimensional lattice random walk in discrete time. We determine the survival probability of the random walker in the presence of an obstacle moving ballistically with velocity v, i.e., the probability that the random walker remains up to time n on the left of the obstacle. Three regimes are to be considered for the long-time behavior of this probability, according to the sign of the difference between v and the drift velocity V¯ of the random walker. In one of these regimes (v>V¯), the survival probability has a nontrivial limit at long times which is discontinuous at all rational values of v. An algebraic approach allows us to compute these discontinuities as well as several related quantities. The mathematical structure underlying the solvability of this model combines elementary number theory, algebraic functions, and algebraic curves defined over the rationals.