Search results for "Observables"
showing 10 items of 31 documents
Polarization observables in elastic electron deuteron scattering including parity and time reversal violating contributions
2000
The general formalism for polarization observables in elastic electron deuteron scattering is extended to incorporate parity and time reversal violating contributions. Parity violating effects arise from the interference of $\gamma$ and $Z$ exchange as well as from the hadronic sector via a small parity violating component in the deuteron. In addition we have allowed for time reversal invariance violating contributions in the hadronic sector. Formal expressions for the additional structure functions are derived, and their decomposition into the various multipole contributions are given explicitly.
Incoherent pion photoproduction on the deuteron with polarization observables I: Formal expressions
2005
Formal expressions are developed for the general five-fold differential cross section of incoherent $\pi$-photoproduction on the deuteron including beam and target polarization. The polarization observables of the cross section are described by various beam, target and beam-target asymmetries for polarized photons and/or polarized deuterons. They are given as bilinear hermitean forms in the reaction matrix elements divided by the unpolarized cross section. In addition, the corresponding observables for the semi-exclusive reaction $\vec d(\vec \gamma,\pi)NN$ are also given.
Polarization observables in deuteron photodisintegration below 360 MeV
2010
High precision measurements of induced and transferred recoil proton polarization in d(polarized gamma, polarized p})n have been performed for photon energies of 277--357 MeV and theta_cm = 20 degrees -- 120 degrees. The measurements were motivated by a longstanding discrepancy between meson-baryon model calculations and data at higher energies. At the low energies of this experiment, theory continues to fail to reproduce the data, indicating that either something is missing in the calculations and/or there is a problem with the accuracy of the nucleon-nucleon potential being used.
Determining the Θ+ quantum numbers through the K+p→π+K+n reaction
2004
Abstract We study the K+p→π+K+n reaction with some kinematics suited to the production of the Θ+ resonance recently observed. We show that, independently of the quantum numbers of the Θ+, a resonance signal is always observed in the K+ forward direction. In addition, we also show how a combined consideration of the strength at the peak, and the angular dependence of polarization observables can help determine the Θ+ quantum numbers using the present reaction.
Study of polarization observables in double pion photoproduction on the proton
2001
Using a model for two pion photoproduction on the proton previously tested in total cross sections and invariant mass distributions, we evaluate here polarization observables on which recent experiments are providing new information. We evaluate cross sections for spin 1/2 and 3/2, which are measured at Mainz and play an important role in tests of the GHD sum rule. We also evaluate the proton polarization asymmetry $\Sigma$ which is currently under investigation at GRAAL in Grenoble.
Relations between polarization observables and complete sets for deuteron photodisintegration
1990
The polarization observables for deuteron photodisintegration are given as Hermitean forms of theT-matrix elementsti. By inversion we are able to express a given productti*tj in terms of polarization observables. This allows (i) to derive linear relations between observables for unpolarized, circularly and linearly polarized photons, (ii) to construct explicitly complete sets of polarization observables, and (iii) to derive quadratic relations between observables.
Polarization Effects in Electromagnetic Deuteron Break-Up
1992
Polarization observables of deuteron photo- and electrodisintegration with polarized photons and electrons, respectively, and oriented deuterons are investigated with respect to their sensitivity to subnuclear degrees of freedom and relativistic effects, to the different electric and magnetic multipole contributions, to various realistic potential models and — in electrodisintegration — to e.m. form factors.
Comment on “Comparison of Polarization Observables in Electron Scattering from the Proton and Deuteron”
1998
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 $…