Mössbauer studies of iron stabilised polymethacrylates

Polymethyl methacrylate (PMMA), polyethyl methacrylate (PEMA) and polybutyl methacrylate (PBuMA) containing ferric chloride and ferrous sulphate as stabilisers, were prepared by free radical polymerization. Mössbauer spactra of ferrous sulphate stabilised polymers don't show any change in the value of isomer shift (1.30 mm/s) while quadrupole splitting values are quite different from those for pure ferrous sulphate. This indicates that environment of Fe²⁺ moiety changes in polymers and thus stabilises the polymers. In case of ferric chloride stabilised polymers the isomer shift values don't differ significantly for different polymethacrylates but quadrupole splitting values increase from polymethyl methacrylate to polybutyl methacrylate. The TGA analysis shows that the inclusion of iron salts stabilises the polymers by 40°C (approx.) and at higher temperatures α-Fe₂O₃ is formed.     

A Markoffian model for hadrons

The hadron is considered as a system consisting of other bound hadrons, the configuration state of which changes with the time. Its time development is described as a Markov process by Kolmogorov's equations. The stationary solution of Kolmogorov's equations for the Markoffian hadronic system makes it possible to calculate certain physical parameters for stable hadrons. The calculation of the magnetic moments of the proton and neutron in this model yields values which are in good agreement with the experimental data.     

Covariant Description of the Interaction of an Electromagnetic Field with Hadrons, Taking into Account Spin Polarizabilities

The covariant Lagrangian of the interaction of an electromagnetic field with polarizable spin hadrons has been constructed invoking sequentially the principle of correspondence between relativistic electrodynamics of moving media and relativistic quantum field theory and taking into account the cross-symmetry condition. It has been shown that for 1/2-spin hadrons, to the third order in radiation frequency, the contribution to the effective Lagrangian is from the spin polarizabilities.     

The structure of the new superspace

The new superspace of Wess and Zumino is generalized to the unconstrainedN-extendedD-dimensional case, it amounts actually to a reparametrization of the old superspace. Recurrence relations for the transformation law and for the covariant derivatives of the superfields defined in the new superspace are obtained. The definition of the component fields as local Lorentz covariant fields has the consequence that the gauge covariant expressions obtained for the vielbein and the connection of the new superspace don't contain the terms dropped out in the Wess-Zumino gauge of supergravity.     

Zur Berechnung der Feldstärke in einem stromdurchflossenen,zylindrischen Entladungsplasma

A method is presented to evaluate the electrical field in a cylindrical low pressure discharge plasma within a consistent quasineutral model. By comparing with a non quasineutral model the limits of applying a quasineutral model are fixed. An iteration procedure is given to evaluate the electrical field for cylindrical plasmas of finite length. The procedure is applied on special models. It resulted, that also at vessels with insulating walls the radial currents generally don't run ambipolar from the axis to the walls. The deviation from ambipolar running can be determined quantitatively.     

Structure of hadron matter: Hierarchy,democracy, or potentiality?

An attempt is made to give a methodological and physical characterization to the concept of the structure of matter. The methodological status of theories describing the structure of hadrons is discussed. A parallelism is drawn between the quark model as a theory of the mathematical composite structure of hadrons and Plato's theory of matter. The merger of the bootstrap idea with a quark substructure of hadrons is discussed. A third approach to the structure of hadron matter is presented. It resembles the Aristotelian conception of primary matter on which form is imprinted potentially.     

Multiplicity distribution in proton-proton and proton-antiproton collisions at high energies

Multiplicity distributions of secondary hadrons produced in p $ \bar p $ \bar p and collisions are very different. There are three types of inelastic processes in p $ \bar p $ \bar p scattering. The first one is the production of a shower of secondary hadrons in gluon string decay. The second one is the shower produced from the decay of two quark strings, and the third one is the shower produced from the decay of three quark strings. At the same time, there are just two types of inelastic processes for pp scattering: the shower from the gluon string and the shower from two quark strings. The multiplicity distribution and the average multiplicity of charged hadrons for an energy of 14 TeV are predicted.     

Classical quark confinement from general relativity

By assuming covariance of physical laws under (discrete) dilatations, it seems possible to describe strong and gravitational interactions in a unified way. An Einstein-type equation with “cosmological” term is for instance suggested for strong field inside hadrons, which yields - among other things - a classical quark confinement in a very natural way. Further consequences are briefly discussed.     

Excited states of light hadrons as a probe of QCD

The dynamics of light hadrons being highly sensitive to the confinement force, it is suggested that a careful study of the excitation pattern of light hadrons might be the most effective way to unravel the mechanisms of confinement dynamics. As a case study, it is shown how the recently confirmed doubling of the ρ' (1600) (which in potential models relies on an accidental level degeneracy) finds a simple interpretation in the framework of a string picture for flux-tube dynamics.     

Quantization and unitary in antisymmetric tensor gauge theories

Following the procedure of Batalin and Vilkovisky we discuss the quantization of a non-abelian antisymmetric tensor gauge theory and describe the verification of one-loop unitarity for the quantized model, using the Ward identities and the procedure of 't Hooft and Veltman. The quantization of this system is similar to that of the Witten string field theory, requiring among other things the presence of three-ghost couplings.     

Röntgentopographische Untersuchungen von 180°-Blochwänden in Eisenwhiskern

The 180°-Bloch walls in iron whiskers are investigated by means of the X-ray topographic method. Normal straight 180°-Bloch walls don't cause any contrasts in the X-ray topographic photographies. In case of the arched 180°-Bloch walls, shown by corresponding Bitter patterns, contrasts could be observed in the X-ray topographics. The zig-zag-walls, a special form of the 180°-Bloch walls, indicated no contrasts in the X-ray topographics as the straight 180°-Bloch walls do.     

Hadrons yielded by plasma

We consider nonequilibrium phase transitions of a quark-gluon plasma into hadrons proceeding via deflagration and supersonic condensation. The possible existence of a third phase, i.e. plasma of constitutent quarks is taken into account. New equations of state for hadronic gas are used, which include the proper volume of particles in a thermodynamically consistent way. The yields of hadrons are calculated for various values of the baryon density of the quark-gluon plasma.     

A φ4-TYPE BAG MODEL OF HADRONS——THE “RUBBER BAG”MODEL Ⅱ.THE MASS SPECTRA OF HADRONS

The mass spectrum of the J/ψ meson family can't be explained by the MIT bagmodel.Based on the theory of our Rubber Bag model of hadrons,the mass spectrumof the ordinary hadrons and that of the J/ψ family (ψ(3772) included) are calcula-ted in a unified way in this paper.The results so obtained conform well to experi-mental data.     

Charmed exotics in heavy ion collisions

Based on the color–spin interaction in diquarks, we argue that charmed multiquark hadrons are likely to exist. Because of the appreciable number of charm quarks produced in central nucleus–nucleus collisions at ultrarelativistic energies, the production of charmed multiquark hadrons is expected to be enhanced in these collisions. Using both the quark coalescence model and the statistical hadronization model, we estimate the yield of charmed tetraquark mesons, T_cc, and pentaquark baryons, Θ_cs, in heavy ion collisions at RHIC and LHC. We further discuss the decay modes of these charmed exotic hadrons in order to facilitate their detections in experiments. PACS 25.75.Dw; 14.20.Lq; 14.40.Lb     

158A GeV的相对论重离子碰撞的强子快度分布及温度拟合

针对最近NA49在158A GeV的实验(C+C,Si+Si,Pb+Pb)数据,应用LUCIAE3.0模型进行模拟,得到了强子的快度分布和横向动量分布,并与实验数据进行比较,发现基本与实验数据相吻合。并对横向动量分布进行温度拟合,给出了和实验数据吻合很好的结果,但是对于重系统或重强子LUCIAE3.0给出的结果与实验符合相对较差.     

Strange particle production in proton-nucleus reactions at ultrarelativistic energies

Enhanced yields of lambdas and other strange hadrons in experiments on nuclear targets at incident energies of 200 GeV have been recently reported by several experimental groups. We calculated events for proton projectiles on different targets in the framework of the relativistic quantum molecular dynamics approach which is based on string excitation and fragmentation with subsequent hadronic collisions. Here we address the question whether the experimentally found lambda enhancement in hadron-nucleus collisions can be understood by interactions of secondary hadrons formed in the target nucleus. Our results for Λ's, kaons and \(\bar \Lambda 's\) agree well with the experimental measurements. We find a doubling of lambda production in the target fragmentation region forp collisions on heavy targets due to nuclear cascading of the produced mesons. Resonances play an important role in creating strange quark pairs confirming earlier findings of their outstanding role inAA collisions.     

基于tri-PLS模型的油类混合物三维荧光光谱及其成分的研究

提出了一种光谱重叠的多种矿物油混合物组分含量测定的新方法。将偏最小二乘方法(PLS)推广至三维扩展(tri-PLS),不需要解决特征值问题。利用该方法对柴油、汽油和煤油混合物的三维荧光光谱进行研究,根据样本序列、激发波长、发射波长构造出三维数据矩阵,结合浓度矩阵应用tri-PLS法建立校正模型,对实验样本进行预测,实验结果表明tri-PLS方法的建模精度比常用的平行因子法优越。     

Parity-violating chiral solitons with vector mesons

The presence of a “phase transition” between the conventional parity-conserving solutions and the spontaneous parity-violating ones is confirmed in the Skyrme model with ϱ, and in a model with ϱ and ω. The parity-violating solutions lead to almost degenerate parity-doublets at the semi-classical level. Since this makes Skyrme's picture of low-lying hadrons troublesome, we obtain a non-trivial constraint for coupling in chiral soliton models with vector mesons.     

Exotic hadron bound state production at hadron colliders

The non-relativistic wave function framework is applied to study the production and decay of exotic hadrons, which can be effectively described as bound states of other hadrons. Employing the factorized formulation,with the help of event generators, we investigate the production of exotic hadrons in multiproduction processes at high energy hadron colliders. This study provides crucial information for the measurements of the relevant exotic hadrons.