Modern Physics Letters A

The t distributions and rapidity gaps in high energy pp collisions are analyzed. For rapidity gaps Δ₁≠Δ₂ of both outgoing nucleons from the central cluster and four-momentum transfers t₁≠ t₂, the Δ_it_i distributions are shown to be the same. It is postulated that this may be interpreted as a limit condition for pure DPE processes. Deviations from this behavior are probably related to non-DPE processes, such as Reggeon–Pomeron and Reggeon–Reggeon exchange.

The possibility exists for improving the present experimental constraint on the tensor coupling constant in radiative pion decay by at least a factor of six. The method emphasizes relative decay probabilities rather than absolute rates.

In this letter, which complements and extends our work⁷ on the superconformal field theories obtained from SWZW models based on general self-dual Lie algebras, we prove the quantum equivalence of the two known descriptions of the gauged supersymmetric WZW model, and as a corollary we show that in the case of the topological G/G gauging, the supersymmetric and nonsupersymmetric theories agree.

We give explicit field theoretical representations for the observables of (2+1)-dimensional Chern–Simons theory in terms of gauge-invariant composites of 2-D WZW fields. To test our identification we compute some basic Wilson loop correlators and re-obtain the known results.

A model of a scalar particle in (2+1)-dimensional space with an internal structure in external electromagnetic fields is considered. Exact solutions of the equation for such scalar particle were obtained in the field of a plane electromagnetic wave with the arbitrary polarization and in the quantized electromagnetic field of the linearly polarized wave. The relativistic coherent states of the particle in the field of n photons were constructed. When the photon number goes to infinity, this wave function transforms to the solution corresponding to the external classical electromagnetic wave.

The electric dipole moment of an electron (EDME) is investigated in the supersymmetric extra U(1) models. Neutralino sector is generally extended in these models and the neutralino contribution will then be important for the analysis of the EDME. Kinetic term mixings of Abelian gauginos are taken into account in our analysis. Numerical results for the extra U(1) models show that the EDME can be affected by the extra U(1) in a certain range of soft supersymmetry breaking parameters even if the extra U(1) gauge boson is heavy. The EDME may be a clue to find an extended gauge structure in the supersymmetric models.

We investigate the discovery potential for first generation leptoquarks at the LEP200 e⁺e^- collider. We consider direct leptoquark searches using single leptoquark production via resolved photon contributions which offers a much higher kinematic limit than the more commonly considered leptoquark pair production process. Depending on the coupling strength of the leptoquark, search limits can be obtained to within a few GeV of . We also consider LQ limits that can be obtained from t-channel interferences effects in e⁺e^-→ hadrons.

We have studied the structure of superheavy nuclei ^294,302120 in the framework of a relativistic mean-field formalism, using three different parameter sets (NL1, NL–SH and TM1) in an axially deformed harmonic oscillator basis. The calculated shapes are found to be parameter-dependent, e.g. NL1 parameter set predicts ³⁰²120 as a spherical and ²⁹⁴120 a very weakly oblate deformed nucleus whereas NL–SH and TM1 parameter sets predict both the nuclei with strongly prolate/oblate deformed configurations, in their respective ground states. This result, coupled with the calculated single-particle energy spectrum for NL1 parameter set, supports for Z=120 nuclei the spherical magic shell more at N=184 than at N=172. Even for the spherical ³⁰²120 nucleus, many new closed shells are predicted and some of the known magic numbers are found absent. Also, the binding energies of the various isotopes of Z=104–111 nuclei are calculated whose comparisons with experimental data favor the NL1 parameter set.