It is shown that in the semi-classical approximation of the electroweak sector of the Standard Model the moduli space of vacua can be identified with the first de Rham cohomology group of space-time. This gives a slightly different physical interpretation of the occurrence of the well-known Ahoronov-Bohm effect. Moreover, when charge conjugation is taken into account, the existence of a non-tri...

We study a similarity transformation to construct an effective Hamiltonian systematically, which does not contain particle-numberchanging interactions. We found it very advantageous that the effective Hamiltonian can be obtained from Feynman diagrams, so that we can use the covariant perturbative renormalization procedure. We apply this to the Light-Front Yukawa model as an example and confirm ...

Results of calculations of the photoelectron spectra for single-photon pulsed-field ionization of the 1p orbital of the X P ~v950! ground state NO leading to the a S ~v50–2! excited ionic state are reported. Agreement between these calculated and recently measured spectra is very encouraging. Comparison of these spectra for ionization of the 1p level of NO ~X P! with those for the 2p orbital re...

An accurate width is determined for the valence band of diamond by imaging photoelectron momentum distributions for a variety of initialand final-state energies. The experimental result of 23.060.2 eV agrees well with first-principles quasiparticle calculations ~23.0 and 22.88 eV! and significantly exceeds the localdensity-functional width, 21.560.2 eV. This difference quantifies effects of cre...

The parent phases of the Fe-arsenide superconductors harbor an antiferromagnetic ground state. Significantly, the Néel transition is either preceded or accompanied by a structural transition that breaks the four-fold symmetry of the high-temperature lattice. Borrowing language from the field of soft condensed matter physics, this broken discrete rotational symmetry is widely referred to as an I...

We show that the radiation damping rate of the transverse action of a particle in a straight, continuous focusing system is independent of the particle energy, and that no quantum excitation is induced. This absolute damping effect leads to the existence of a transverse ground state which the particle inevitably decays to, and yields the minimum beam emittance that one can ever attain, YE,;, = ...

Ground surfaces play an important role in terrestrial species' locomotion and ability to manipulate objects. In humans, ground surfaces have been found to offer significant advantages in distance perception and visual-search tasks ("ground dominance"). The present study used a comparative perspective to investigate the ground-dominance effect in chimpanzees, a species that spends time both on t...

Regarding the importance of the prevention of hazards and adverse environmental impacts in industrial and populated areas such as southern parts of Tehran city, the response of impulsive period ground-supported tanks were assessed. Having considered the study area's soil properties, the response of ground-supported tanks was modelled. Regarding the soil properties of southern parts of Tehran, t...

time-dependent schrödinger equation for a 1-d model of hydrogen molecular ion h2+ in intenselaser field linearly polarized along the molecular axis is solved. ionization rates are calculated for differentinitial states. the evolution of electronic wavefunction at fixed inter-nuclear separations are simulated andanalyzed. the results obtained for the ground state of this 1-d model of h2+ show ap...