Search results for "polarization [quarkonium]"

Analytical design of densely dispersion-managed optical fiber transmission systems with Gaussian and raised cosine return-to-zero Ansätze

2004

We propose an easy and efficient way to analytically design densely dispersion-managed fiber systems for ultrafast optical communications. This analytical design is based on the exact solution of the variational equations derived from the nonlinear Schrodinger equation by use of either a Gaussian or a raised-cosine (RC) Ansatz. For the input pulses of dispersion-managed optical fiber transmission systems we consider a RC profile and show that RC return-to-zero pulses are as effective as Gaussian pulses in high-speed (160-Gbits/s) long-distance transmissions.

All-optical simultaneous polarization attraction and intensity regeneration of a 40-Gbit/s RZ signal

2011

We experimentally report the dual all-optical instantaneous regeneration of both the state of polarization and the intensity profile of a 40 Gbit/s Return-to-Zero telecommunication signal by means of a unique segment fiber.

Probing new physics in B¯0→D(*)τ−ν¯τ using the longitudinal, transverse, and normal polarization components of the tau lepton

2017

We study the longitudinal, transverse, and normal polarization components of the tau lepton in the decays ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{(*)}{\ensuremath{\tau}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\tau}}$ and discuss their role in searching for new physics (NP) beyond the standard model (SM). Starting with a model-independent effective Hamiltonian including non-SM four-Fermi operators, we obtain experimental constraints on different NP scenarios and investigate their effects on the polarization observables. In the SM the longitudinal and transverse polarizations of the tau lepton differ substantially from the corresponding zero lepton mass values of $…

Atlas of Polarization Observables

1991

Semileptonic decaysΛc+→Λℓ+νℓ(ℓ=e,μ)in the covariant quark model and comparison with the new absolute branching fraction measurements of Belle and BES…

2016

We present precise theoretical predictions for the absolute branching fractions of ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}(\ensuremath{\ell}=e,\ensuremath{\mu})$ decays in the covariant confined quark model. This study is motivated by two recent and accurate measurements of the absolute branching fractions of ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ and ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}{e}^{+}{\ensuremath{\nu}}_{e}$ by the Belle Collaboration at the KE…

Pion Photo- and Electroproduction on the Proton

1999

Using a unitary isobar model a new operator for pion photo- and electroproduction has been developed for nuclear applications at photon equivalent energies up to 1 GeV. The model contains Born terms, vector mesons and nucleon resonances (P 33(1232), P 11(1440), D 13(1520), S 11(1535), F 15(1680), and D 33(1700)). Within this model we have obtained good agreement with the experimental data for pion photo- and electroproduction on the nucleon for both differential cross sections and polarization observables.

Dispersion theoretical analysis of the nucleon spin polarizabilities

1999

The spin polarizabilities of the nucleon have been calculated from pion photoproduction data using forward dispersion relations. The feasibility of an experimental determination of these structure constants is discussed by focusing on polarization observables of the reaction \( \vec{\gamma }\vec{p} \to \gamma p \)→ γ p.

Dark-soliton-like pulse-train generation from induced modulational polarization instability in a birefringent fiber

1998

Theory and experiments show that the nonlinear development of the modulational polarization instability of an intense light beam in a normally dispersive, low-birefringence optical fiber leads to ultrashort dark-soliton-like trains with repetition rates in the terahertz range in the polarization orthogonal to the pump.

Transmission and phase measurement for polarization eigenvectors in twisted-nematic liquid crystal spatial light modulators

1998

Recently we published theoretical expressions for the eigenvalues and eigenvectors for a twisted-nematic liquid crystal spatial light modulator (LCSLM) as a function of the twist angle and birefringence using the Jones matrix formalism. These polarization eigenvectors are of interest for newer video graphics adapter (VGA) resolution (640 3480 pixels) LCSLMs that are thinner and consequently have a lower birefringence. Although these devices can produce excellent amplitude modulation, they cannot achieve phase-only modulation using linearly polarized light. In these cases, the polarization eigenvectors are required to obtain phase-only modulation. We present experimental measurements for bot…

Polarization of the Radiation Emitted in GaAs Semiconductors Driven by Far Infrared Fields

2010

The effects due to the mixing of two far infrared electric fields on the harmonic generation process in low doped GaAs bulks are studied by a three dimensional multivalleys Monte Carlo simulation. The conversion efficiency is calculated by using the appropriate Maxwell equation for the propagation of an electro-magnetic wave along a given direction in the medium. In particular, we focus our attention on the polarization of the generated harmonics, by comparing the polarization obtained from the mixing of an oscillating field with a static electric field with that obtained in the presence of two cyclostationary fields, having an integer ratio between the two frequencies. The findings show th…