A local gauge invariant infrared regularization of the Yang-Mills theory

A local gauge invariant infrared regularization for the Yang-Mills theory is constructed on the basis of a higher derivative formulation of the model.Comment: 7 page

Behaviour of the potentials due to strangeness degree of freedom in ΛΛ6_{\Lambda\Lambda}^6He hypernucleus

Fully correlated study of $_{\Lambda\Lambda} ^6$He hypernucleus has been performed with two- and three- baryon potentials. For the S=-2 sector, various simulations of Nijmegen $\Lambda\Lambda$ potential models have been used. We investigate the role of every strength of the strange sector potentials on the energy breakdown and present a crystal clear understanding of their interplay. Consistency between $_\Lambda ^5$He and $_{\Lambda\Lambda}^6$He depends on the $\Lambda N$ space-exchange strength only. Investigation limits the strength of simulated Nijmegen $\Lambda\Lambda$ potential models. The study is a step forward to determine all the strengths, to reslove A=5 anomaly and to search for $_{\Lambda\Lambda}^4$H in an authentic way.Comment: 4 pages, 1 figur

Antiferromagnetic fluctuations, symmetry and shape of the gap function in the electron-doped superconductors: the functional renormalization-group analysis

The problem of the symmetry of the superconducting pairing and the form of the gap function in the electron-doped superconductors is reconsidered within the temperature-cutoff functional renormalization group approach combined with the Bethe-Salpeter equations. The momentum dependence of the order parameter for antiferromagnetic and superconducting instabilities in these compounds is analyzed. The gap function in the antiferromagnetic (particle-hole) channel has its maxima at the hot-spots, or at the diagonal of the Brilloin zone in their absence. The wavefunction in the singlet superconducting channel is non-monotonic in the vicinity of the (pi,0) and (0,pi) points, in striking similarity with recent experimental data. An instability in the triplet superconducting channel is much weaker than the singlet one and has an f-wave like form of the gap function.Comment: 4 pages, RevTe

Ground state of the holes localized in II-VI quantum dots with Gaussian potential profiles

We report on the theoretical study of the hole states in II-IV quantum dots of a spherical and ellipsoidal shape, described by a smooth potential confinement profiles, that can be modelled by a Gaussian functions in all three dimensions. The universal dependencies of the hole energy, $g$-factor and localization length on a quantum dot barrier height, as well as the ratio of effective masses of the light and heavy holes are presented for the spherical quantum dots. The splitting of the four-fold degenerate ground state into two doublets is derived for anisotropic (oblate or prolate) quantum dots. Variational calculations are combined with numerical ones in the framework of the Luttinger Hamiltonian. Constructed trial functions are optimized by comparison with the numerical results. The effective hole $g$-factor is found to be independent on the quantum dot size and barrier height and is approximated by simple universal expression depending only on the effective mass parameters. The results can be used for interpreting and analyzing experimental spectra measured in various structures with the quantum dots of different semiconductor materials.Comment: 13 pages, 8 figure