Search results for "fire"
showing 10 items of 463 documents
Observability of the Neutrino Charge Radius
2002
It is shown that the probe-independent charge radius of the neutrino is a physical observable; as such, it may be extracted from experiment, at least in principle. This is accomplished by expressing a set of experimental ${\ensuremath{\nu}}_{\ensuremath{\mu}}\mathrm{\text{\ensuremath{-}}}e$ cross sections in terms of the finite charge radius and two additional gauge- and renormalization-group-invariant quantities, corresponding to the electroweak effective charge and mixing angle.
Signatures of bosonic squark decays in non-minimally flavour-violating supersymmetry
2010
We investigate couplings of squarks to gauge and Higgs-bosons within the framework of non-minimal flavour violation in the Minimal Supersymmetric Standard Model. Introducing non-diagonal elements in the mass matrices of squarks, we first study their impact on the self-energies and physical mass eigenvalues of squarks. We then present an extensive analysis of bosonic squark decays for variations of the flavour-violating parameters around the two benchmark scenarios SPS1a' and SPS1b. Signatures, that would be characteristic for a non-minimal flavour structure in the squark sector, can be found in wide regions of the parameter space.
Systematic Study of Horizontal Gauge Theories
1995
We analyze all the possible continuous horizontal gauge groups G_H in relation with their possibility to explain m_b<<m_t. We assume that the only effective fermionic degrees of freedom correspond to the known fermions but allow the possibility of adding a right handed neutrino to each family. We assume that the Higgs fields which generate masses for these fermions, trough renormalizable Yukawa couplings, transform as an irreducible representation of SU(3)_c\otimesSU(2)_L\otimesU(1)_Y\otimesG_H. Under these assumptions we find two U(1)_H or U(1)_{H1}\otimesU(1)_{H2} models free of anomalies and able to guarantee that only the top has a renormalizable mass-generating Yukawa coupling.
J/\psi depletion in a nuclear medium
2012
In this talk, we have taken into account the main decay channel of J/ψ when travelling inside a nucleus. In analogy to all vector mesons in SU(3), where the main decay channel is to two pseudoscalars, in the case of the J/ψ the meson meson channel to which it couples strongly is DD. Taking this into account we study the J/ψN → DΛc and J/ψN → DΣc mediated by D-exchange. To obtain the couplings we use an extension to SU(4) of the local hidden gauge Lagrangians as done in [1]. Analogously, we consider the mechanisms where the exchanged D collides with a nucleon and gives πΛc or πΣc. The sum of these channels produces a J/ψN inelastic cross section which is larger than the elastic one and is re…
Gauge-invariant Non-spherical Metric Perturbations of Schwarzschild Black-Hole Spacetimes
2005
The theory of gauge-invariant non-spherical metric perturbations of Schwarzschild black hole spacetimes is now well established. Yet, as different notations and conventions have been used throughout the years, the literature on the subject is often confusing and sometimes confused. The purpose of this paper is to review and collect the relevant expressions related to the Regge-Wheeler and Zerilli equations for the odd and even-parity perturbations of a Schwarzschild spacetime. Special attention is paid to the form they assume in the presence of matter-sources and, for the two most popular conventions in the literature, to the asymptotic expressions and gravitational-wave amplitudes. Besides…
Mr. Maxwell's journey into hadron country (electromagnetic currents in nuclei)
1993
In these lectures an introduction is given into the main features of nuclear structure investigations by photoabsorption and electron scattering. After a brief review of the general structure of the electromagnetic interaction, the gauge conditions and low-energy theorems for the electromagnetic interaction operators are discussed. The various theoretical schemes for incorporating subnuclear degrees of freedom either as effective operators like the pion exchange current or explicitely like in the model of nuclear isobar configurations are reviewed. At the end, a few specific experiments are discussed as an illustration of what can be learned from such experiments.
EMBEDDED STRAIN GAUGES: EFFECT OF THE STRESS NORMAL TO THE GRID
2005
: In general, a strain gauge embedded in a model is subjected to a stress normal to the grid, whereas a gauge on the external surface is free from such a stress. This paper concerns the effect of the stress normal to the grid on the output of the strain gauge; usually, the influence of such a stress has a negligible effect, however, in some cases a notable influence has been noted. Therefore, the output of the strain gauge is determined in function of the strains in the plane of the gauge, ɛl and ɛt, and of the stress, σn, normal to the grid. The analysis shows that the output of the strain gauge is influenced by the coupled effect of transverse sensitivity and pressure sensitivity of the …
Quantum walks and non-Abelian discrete gauge theory
2016
A new family of discrete-time quantum walks (DTQWs) on the line with an exact discrete $U(N)$ gauge invariance is introduced. It is shown that the continuous limit of these DTQWs, when it exists, coincides with the dynamics of a Dirac fermion coupled to usual $U(N)$ gauge fields in $2D$ spacetime. A discrete generalization of the usual $U(N)$ curvature is also constructed. An alternate interpretation of these results in terms of superimposed $U(1)$ Maxwell fields and $SU(N)$ gauge fields is discussed in the Appendix. Numerical simulations are also presented, which explore the convergence of the DTQWs towards their continuous limit and which also compare the DTQWs with classical (i.e. non-qu…
Two Dimensional Quantum Chromodynamics as the Limit of Higher Dimensional Theories
1994
We define pure gauge $QCD$ on an infinite strip of width $L$. Techniques similar to those used in finite $TQCD$ allow us to relate $3D$-observables to pure $QCD_2$ behaviors. The non triviality of the $L \arrow 0$ limit is proven and the generalization to four dimensions described. The glueball spectrum of the theory in the small width limit is calculated and compared to that of the two dimensional theory.
A study of beauty baryons with extended local hidden gauge approach
2016
Abstract In present work we investigate the interaction of B ‾ N , B ‾ Δ , B ‾ ⁎ N and B ‾ ⁎ Δ states, together with their coupled channels. Taking into account the heavy quark spin symmetry for pion exchange and the results of the Weinberg Tomozawa term in the extended local hidden gauge approach, we search for states dynamically generated from the interaction, and find two states with small width, which we associate to the Λ b ( 5912 ) and Λ b ( 5920 ) states. In addition to these two Λ b states, we find three more states with I = 0 and eight more states in I = 1 , some of which are degenerate in different spin J .