We have performed a global analysis of muon decay measurements to establish model-independent limits on the space-time structure of the muon decay matrix element. We find limits on the scalar, vector and tensor coupling of right-and left-handed muons to right-and left-handed electrons. The limits on those terms that involve the decay of right-handed muons to left-handed electrons are more restr...

A brief review of the recent developments in the physics from extra dimensions is given with a focus on the effects of Kaluza-Klein excitations in the Standard Model sector. It is shown that the current accurate data on the Fermi constant and on other electro-weak parameters puts a lower bound on the scale of extra dimensions of∼ 3 TeV, and thus the observation of such dimensions lies beyond th...

The superconducting sesquicarbides R2C3 have noncentrosymmetric point group symmetry Td. Spin-orbit coupling lifts the spin degeneracy of electronic bands in the most of the Brillouin zone. Nevertheless, due to high symmetry, there are a few directions along which the Fermi surfaces must touch. This leads to two-band effects in the superconducting state.

P. E. Mijnarends,1,2 S. Kaprzyk,1,3 B. Barbiellini,1 Yinwan Li,4,5 J. F. Mitchell,5 P. A. Montano,4,6 and A. Bansil1 1Physics Department, Northeastern University, Boston, Massachusetts 02115, USA 2Department of Radiation, Radionuclides & Reactors, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands 3Academy of Mining and Metallurgy AGH, 30059 Krakow, Poland 4Depa...

We study the quantum decay of D0-branes in two-dimensional 0B string theory. The quantum nature of the branes provides a natural cut-off for the closed string emission rate. We find exact quantum mechanical wavefunctions for the decaying branes and show how one can include the effects of the Fermi sea for any string coupling (Fermi energy). J.A. and R.J. were supported by MaPhySto – A Network i...

Differently prepared surfaces of quasicrystalline i-Al-Pd-Mn are analyzed using angle-resolved photoemission in the x-ray and ultraviolet range of photon energies. Depending on the preparation, we find both surfaces with crystalline structure and metallic character, and surfaces with quasicrystalline structural fingerprints and a suppressed density of states at the Fermi level, compatible with ...

The Lieb-Thirring inequalities give a bound on the negative eigenvalues of a Schrödinger operator in terms of an L norm of the potential. These are dual to bounds on the H-norms of a system of orthonormal functions. Here we extend these bounds to analogous inequalities for perturbations of the Fermi sea of non-interacting particles, i.e., for perturbations of the continuous spectrum of the Lapl...

We use microscopic many-body theory to analyze the problem of itinerant ferromagnetism in a repulsive atomic Fermi gas of hard spheres. Using simple arguments we show that the available theoretical predictions for the onset of the ferromagnetic transition predict a transition point at a density (kF a ∼ 1) that is too large to be compatible with the universal low-density expansion of the energy....

Red quasars are a population, characterized by significant extinction in UV, which could be explained by absorption of dusty gas on a scale of a few kpc. We show that the enhanced radiation-pressure drives the dusty gas to supersonically expand and produces shocks. The shocks energize electrons to be relativistic via the first Fermi acceleration. As a balance of shock acceleration and synchrotr...