Search results for "REPRESENTATION"
showing 10 items of 1710 documents
Unified framework for generalized and transverse-momentum dependent parton distributions within a 3Q light-cone picture of the nucleon
2011
We present a systematic study of generalized transverse-momentum dependent parton distributions (GTMDs). By taking specific limits or projections, these GTMDs yield various transverse-momentum dependent and generalized parton distributions, thus providing a unified framework to simultaneously model different observables. We present such simultaneous modeling by considering a light-cone wave function overlap representation of the GTMDs. We construct the different quark-quark correlation functions from the 3-quark Fock components within both the light-front constituent quark model as well as within the chiral quark-soliton model. We provide a comparison with available data and make prediction…
A general parametrization for the long-range part of neutrinoless double beta decay
1997
Double beta decay has been proven to be a powerful tool to constrain $B-L$ violating physics beyond the standard model. We present a representation for the long-range part of the general $0\nu\beta\beta$ decay rate allowed by Lorentz-invariance. Combined with the short range part this general parametrization in terms of effective $B-L$ violating couplings will provide the $0\nu\beta\beta$ limits on arbitrary lepton number violating theories.
Nuclear effects in F_3 structure function of nucleon
2008
We study nuclear effects in the $F^A_3(x)$ structure function in the deep inelastic neutrino reactions on iron by using a relativistic framework to describe the nucleon spectral functions in the nucleus. The results for the ratio $R(x,Q^2)=\frac{F^A_3(x,Q^2)}{AF^N_3(x, Q^2)}$ and the Gross-Llewellyn Smith(GLS) integral $G(x,Q^2)=\int_x^1 dx F^A_3(x,Q^2)$ in nuclei are discussed and compared with the recent results available in literature from theoretical and phenomenological analyses of experimental data.
Leptonicμandτdecays: Mass effects, polarization effects, andO(α)radiative corrections
2003
We calculate the radiative corrections to the unpolarized and the four polarized spectrum and rate functions in the leptonic decay of a polarizedinto a polarized electron. The new feature of our calculation is that we keep the mass of the final state electron finite which is mandatory if one wants to investigate the threshold region of the decay. Analytical results are given for the energy spectrum and the polar angle distribution of the final state electron whose longitudinal and transverse polarization is calculated. We also provide analytical results on the integrated spec- trum functions. We analyze the me → 0 limit of our general results and investigate the quality of the me → 0 approx…
-Poincaré supergravities from Lie algebra expansions
2012
Abstract We use the expansion of superalgebras procedure (summarized in the text) to derive Chern–Simons (CS) actions for the ( p , q ) -Poincare supergravities in three-dimensional spacetimes. After deriving the action for the ( p , 0 ) -Poincare supergravity as a CS theory for the expansion osp ( p | 2 ; R ) ( 2 , 1 ) of osp ( p | 2 ; R ) , we find the general ( p , q ) -Poincare superalgebras and their associated D = 3 supergravity actions as CS gauge theories from an expansion of the simple osp ( p + q | 2 , R ) superalgebras, namely osp ( p + q | 2 , R ) ( 2 , 1 , 2 ) .
I=1/2 S -wave and P -wave Kπ scattering and the κ and K* resonances from lattice QCD
2020
We present a lattice-QCD determination of the elastic isospin-$1/2$ $S$-wave and $P$-wave $K\ensuremath{\pi}$ scattering amplitudes as a function of the center-of-mass energy using L\"uscher's method. We perform global fits of $K$-matrix parametrizations to the finite-volume energy spectra for all irreducible representations with total momenta up to $\sqrt{3}\frac{2\ensuremath{\pi}}{L}$; this includes irreducible representations (irreps) that mix the $S$- and $P$-waves. Several different parametrizations for the energy dependence of the $K$-matrix are considered. We also determine the positions of the nearest poles in the scattering amplitudes, which correspond to the broad $\ensuremath{\ka…
Lattice QCD calculation of the electroweak box diagrams for the kaon semileptonic decays
2021
We present a lattice QCD calculation of the axial $\gamma W$-box diagrams relevant for the kaon semileptonic decays. We utilize a recently proposed method, which connects the electroweak radiative corrections in Sirlin's representation to that in chiral perturbation theory. It allows us to use the axial $\gamma W$-box correction in the SU(3) limit to obtain the low energy constants for chiral perturbation theory. From first principles our results confirm the previously used low energy constants provided by the minimal resonance model with a significant reduction in uncertainties.
Monte Carlo techniques in small-x physics: Formal studies and phenomenology
2013
We discuss the solution to the BFKL equation in the adjoint representation at LO and NLO accuracy for the N = 4 SUSY theory. We use Monte Carlo techniques to study numerically the Gluon Green’s function at LO and NLO directly written in the transverse momentum space which allows for the factorization of its infrared divergencies. Finally, we discuss the applicability of our approach to phenomenological searches for the BKP Odderon at the LHC.
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.
N-qubit states as points on the Bloch sphere
2009
We show how the Majorana representation can be used to express the pure states of an N-qubit system as points on the Bloch sphere. We compare this geometrical representation of N-qubit states with an alternative one, proposed recently by the present authors.