We obtain various explicit solutions to the interior Einstein–Maxwell field equations corresponding to charged fluid spheres in the Einstein–Cartan theory. The physical 3-space \(t =\) constant of the solution is spheroidal. The physical features of one of these solutions are also discussed.
It is shown that instanton-anti-instanton induce a negative infrared finite vacuum energy in massless supersymmetric QCD. In the massive theory the same field configuration induces no vacuum energy because its classical action diverges due to the contribution of the mass term. Only if the scalar field is classically zero (in a background of an instanton-anti- -instanton) a vacuum energy is found in the massive theory. However, it is negative and infrared divergent.
We quantize canonically the scalar field in the theory with higher derivatives. We show that the results are consistent with those obtained in the theory without higher derivatives.
The nuclear quark distribution functions are obtained in the framework of the multiquark cluster model and with these distribution functions Drell–Yan cross sections for lepton pair production processes in hadron–nuclear collisions are calculated. Significant nuclear effects are predicted for the ratios of cross sections in the region of large \(M\) and negative \(X_F\). Results of the calculations. are compared with existing experimental data.
The internal consistency of various methods of improving the static spherical cavity approximation to the MIT Bag Model is investigated by studying electromagnetic current matrix elements between boosted bag and the boosted hadron states. In the case when the bag state is identified with the hadron bound in an external potential the consistency requirement fixes parameters of this potential allowing to calculate the improved values of the electromagnetic properties of nucleons.
In the paper the generator coordinate method is reformulated to show its symmetry conservation property. The equations for the eigenvalues and eigenvectors of an overlap operator for the case of compact groups are derived. A rotational motion of an axially symmetric nuclear system is considered.
The possibility of dynamical symmetry breaking in the field theory limit of superstring theories is discussed. The proposed scenario should lead to a natural solution to the hierarchy problem.