Search results for "DIPOLE"

Beam optics and magnet technology of the microtron in mainz

1981

Abstract A description is given of the beam transport system for injection into the first microtron of MAMI. Further, a special procedure to improve the field distribution of the dipole magnets is described in some detail and results are given.

Neutrinoless ββ nuclear matrix elements using isovector spin-dipole Jπ=2− data

2018

EDM observables for τ production with polarized beams

2008

The Tau-lepton electric dipole moment (EDM) can be measured at Super B/Flavor factories operating with polarized electron beams at energies near and on top of the ¤ resonances. In particular, new CP-odd observables, independent from others already considered, will allow to put stringent bounds on the ? EDM.

Determination of quadrupole strengths in the γ∗p→Δ(1232) transition at Q2=0.20(GeV/c)2

2007

Abstract We report new precise p ( e → , e ′ p ) π 0 measurements at the peak of the Δ + ( 1232 ) resonance at Q 2 = 0.20 ( GeV / c ) 2 performed at the Mainz Microtron (MAMI). The new data are sensitive to both the electric (E2) and the Coulomb (C2) quadrupole amplitudes of the γ ∗ N → Δ transition. They yield precise quadrupole to dipole amplitude ratios: CMR = ( − 5.09 ± 0.28 stat + sys ± 0.30 model ) % and EMR = ( − 1.96 ± 0.68 stat + sys ± 0.41 model ) % for M 1 + 3 / 2 = ( 39.57 ± 0.75 stat + sys ± 0.40 model ) ( 10 −3 / m π + ) . The new results are in disagreement with Constituent Quark Model predictions and in qualitative agreement with models that account for mesonic contributions…

Final report on the CERN muon storage ring including the anomalous magnetic moment and the electric dipole moment of the muon, and a direct test of r…

1978

Abstract A comprehensive description of the muon storage ring and its operation is given, and the final results of the experiment are presented and discussed. The anomalous magnetic moments of positive and negative muons are found to be aμ+ = 1165911(11) × 10−9 and aμ− = 1165937(12) × 10−9 giving an average value for muons of aμ = 1165924(8.5) × 10−9. The electric dipole moments were also measured with the results Dμ+= (8.6 ± 4.5) × 10−9e · cm and Dμ− = (0.8 ± 4.3) × 10−19e · cm. Under the assumption of the CPT theorem these yield a weighted average of Dμ = (3.7 ± 3.4) × 10−19e · cm. Finally the time transformation of special relativity is shown to be valid to (0.8 ± 0.7) × 10−3 at γ ≅ 29.3…

Direct decay of the giant dipole resonance in58,60Ni and64Zn from (e, � c) experiments

1988

(e,e'c) coincidence experiments at a momentum transfer of q=0.27 fm−1 to study the decay of the giant dipole resonance in58,60Ni and64Zn show deviations from photonuclear results and reveal strong contributions of direct decay to proton hole states.

Excitation and decay of two-phonon giant dipole resonances

1999

Abstract In heavy ion collisions at near relativistic energies, electromagnetic excitation of the double giant dipole resonance occurs with large cross sections. We summarize the presently available experimental data and discuss related theoretical efforts. Emphasis is paid to the question of anharmonicities and to the damping of the two-phonon states.

HADRONIC CROSS SECTION MEASUREMENT AT BES-III

2014

Measurements of the R ratio are closely related to two pre quantities, the anomalous magnetic moment of the muon (g - 2), and the value of the electromagnetic fine structure constant [Formula: see text]. Hadronic contributions to both quantities can be derived via dispersion integrals, using experimental R data as input. For the phenomenological evaluations of these contributions, different energy ranges of hadronic cross section data are required. At BES-III, Initial State Radiation (ISR) from an existing Ψ(3770) dataset will be used for measurements of hadronic cross sections below [Formula: see text], while for higher energies a dedicated energy scan program will be performed up to [For…

Leptons and QCD

2015

Three important QCD-related aspects of the τ and μ dynamics are reviewed: the determination of the strong coupling from the hadronic tau decay width, leading to the updated value αs(mτ2)=0.331±0.013; the measurement of |Vus| through the Cabibbo-suppressed decays of the τ, and the Standard Model prediction for the muon anomalous magnetic moment.

Real and Virtual Compton Scattering (experiments)

1999

This paper deals with Real and Virtual Compton Scattering off the proton at threshold and the way to deduce information about the nucleon polarizabilities.