POLARIZED PARITY VIOLATING ELECTRON SCATTERING ON 3H AND ITS RELATION TO THE 3He CASE

2000 ◽  
Vol 09 (01) ◽  
pp. 1-16
Author(s):  
S. L. MINTZ ◽  
G. M. GERSTNER ◽  
M. A. BARNETT ◽  
M. POURKAVIANI
Keyword(s):  
Electron Scattering ◽  
Strange Quark ◽  
Form Factors ◽  
High Sensitivity ◽  
Figures Of Merit ◽  
Weak Minimum ◽  
Sharp Variation ◽  
The Asymmetry ◽  
The Difference ◽  
Asymmetry Parameters

We calculate the asymmetry parameters, A, and figures-of-merit for polarized parity violating electron scattering from 3 H via the reaction, e- + 3 H → 3 H + e- for incident electron energies of 1.0 GeV, 2.0 GeV, and 4.0 GeV. We find a sharp variation in A due to cancellations between the weak and electromagnetic form factors caused by the different q2 dependences of these form factors. These variations are similar to those found in the asymmetry for the reaction, e- + 3 He → e- + 3 He but occur at different angles due to the difference in form factors for the two cases. We find that at small angles, the asymmetry may be obtained to reasonably high accuracy for all energies considered and that there is a weak minimum in it at small angles for all of the energies considered here. We show that it might be possible to observe strange quark contributions to the asymmetry at this minimum due to the high sensitivity of A to strange quark contributions in this region. In addition we find that the asymmetry and figures of merit are in the range of those for other proposed target nuclei.

scholarly journals Elastic electron scattering from 17Ne and 27P exotic nuclei

2019 ◽  
Vol 13 (28) ◽  
pp. 68-81
Author(s):  
A. R. Ridha
Keyword(s):  
Electron Scattering ◽  
Form Factors ◽  
Computer Code ◽  
Exotic Nuclei ◽  
Proton Density ◽  
Elastic Electron ◽  
Elastic Electron Scattering ◽  
The Difference ◽  
Proton Form Factors ◽  
Near Future

The ground state proton, neutron and matter densities andcorresponding root mean square radii of unstable proton-rich 17Neand 27P exotic nuclei are studied via the framework of the twofrequencyshell model. The single particle harmonic oscillator wavefunctions are used in this model with two different oscillator sizeparameters core b and halo , b the former for the core (inner) orbitswhereas the latter for the halo (outer) orbits. Shell model calculationsfor core nucleons and for outer (halo) nucleons in exotic nuclei areperformed individually via the computer code OXBASH. Halostructure of 17Ne and 27P nuclei is confirmed. It is found that thestructure of 17Ne and 27P nuclei have 25 / 2 (1d ) and 1/ 2 2s -dominantconfigurations, respectively. Elastic electron scattering form factorsof these exotic nuclei are also studied using the plane wave Bornapproximation. Effects of the long tail behavior of the proton densitydistribution on the proton form factors of 17Ne and 27P areanalyzed. It is found that the difference between the proton formfactor of 17Ne and that of stable 20Ne (or of 27P and that of stable31P) comes from the difference in the proton density distribution ofthe last two protons (or of the last proton) in the two nuclei. It isconcluded that elastic electron scattering will be an efficient tool (inthe near future) to examine proton-halo phenomena of proton-richnuclei.

scholarly journals THE NUCLEON'S MIRROR IMAGE: REVEALING THE STRANGE AND UNEXPECTED

2003 ◽  
Vol 18 (02n06) ◽  
pp. 75-84 ◽  
Author(s):  
R. D. MCKEOWN
Keyword(s):  
Form Factor ◽  
Electron Scattering ◽  
Strange Quark ◽  
Form Factors ◽  
Mirror Image ◽  
Vector Form ◽  
Electromagnetic Structure ◽  
Extensive Program ◽  
Axial Form ◽  
Insight Into

An extensive program of parity-violating electron scattering experiments is providing new insight into the structure of the nucleon. Measurement of the vector form factors enables a definitive study of potential strange quark-antiquark contributions to the nucleon's electromagnetic structure, including the magnetic moment and charge distribution. Recent experimental results have already indicated that effects of strangeness are much smaller than theoretically expected. In addition, the neutral axial form factor appears to display substantial corrections as one might expect from an anapole effect.

Superfluidity of electron–hole pairs between two critical temperatures

2015 ◽  
Vol 29 (27) ◽  
pp. 1550188 ◽  
Author(s):  
Ilya Grigorenko ◽  
Roman Ya. Kezerashvili
Keyword(s):  
Critical Temperatures ◽  
Electron Hole ◽  
Superfluid State ◽  
Chemical Potentials ◽  
Wide Range ◽  
The Asymmetry ◽  
The Difference ◽  
The Stability ◽  
Simple Linear Equation ◽  
Asymmetry Parameters

We study a system of spatially separated electrons and holes, assuming the carriers are confined to two parallel planes. The existence of the superfluid state of electron–hole pairs between two critical temperatures is predicted for such system in a case of electron–hole asymmetry caused by the difference in the carrier masses and their chemical potentials. The stability of the superfluid state is studied with respect to the changes of the asymmetry between electrons and holes. It is found that one type of the asymmetry can compensate another one, so the superfluid state is possible in a wide range of the asymmetry parameters when they satisfy a simple linear equation.

scholarly journals Elastic transverse electron scattering form factors of 11Li exotic nucleus

2019 ◽  
Vol 12 (23) ◽  
pp. 65-72
Author(s):  
B. S. Hameed
Keyword(s):  
Shell Model ◽  
Electron Scattering ◽  
Exotic Nucleus ◽  
Form Factors ◽  
Model Space ◽  
Model Calculations ◽  
Plane Wave Born Approximation ◽  
The Difference ◽  
Elastic Transverse ◽  
Transverse Electron

        The elastic transverse electron scattering form factors have been studied for the 11Li   nucleus using the Two- Frequency Shell Model (TFSM) approach. The single-particle wave functions of harmonic-oscillator (HO) potential are used with two different oscillator parameters bcore and bhalo. According to this model, the core nucleons of 9Li nucleus are assumed to move in the model space of spsdpf. The outer halo (2-neutron) in 11Li is assumed to move in the pure 1p1/2, 1d5/2, 2s1/2 orbit. The shell model calculations are carried out for core nucleons using the spsdpf-interaction.  The elastic magnetic electron scattering of the stable 7Li and exotic 11Li nuclei are also investigated through Plane Wave Born Approximation (PWBA). It is found that the difference between the total form factors of unstable isotope (11Li halo) and stable isotope 7Li is in magnitude. The measured value of the magnetic moment is also reproduced.

ASYMMETRIES IN POLARIZED ELECTRON SCATTERING AND THE STRANGENESS CONTENT OF THE NUCLEON

2009 ◽  
Vol 24 (11n13) ◽  
pp. 881-886
Author(s):  
SEBASTIAN BAUNACK
Keyword(s):  
Electron Scattering ◽  
Strange Quark ◽  
Form Factors ◽  
Strange Quarks ◽  
Quark Contribution ◽  
Nucleon Form Factors ◽  
Strangeness Content ◽  
Existing Data

In the viewpoint of QCD, the nucleon is made up of constituent quarks, sea quarks and gluons. Concerning the quark sea, also strange quarks can contribute to the nucleon properties. Parity violating electron scattering offers a tool to investigate the strange quark contribution to the nucleon form factors. The measurements of different experiments are discussed and the recent results from the A4 collaboration at MAMI is presented. Altogether the existing data allow to give constraints on the strangeness contribution.

scholarly journals Λ hyperon spin polarization and CP tests at BESIII

2019 ◽  
Vol 199 ◽  
pp. 03009
Author(s):  
P. Adlarson ◽  
C. Li
Keyword(s):  
Form Factor ◽  
Simultaneous Measurement ◽  
Form Factors ◽  
Effective Form ◽  
Complete Measurement ◽  
The Asymmetry ◽  
Decay Parameters ◽  
First Time ◽  
Resonant Processes ◽  
Asymmetry Parameters

In these proceedings two preliminary results from the BESIII collaboration on polarized Λ and $\bar \Lambda$ are reported. Both results are first observations and concern the resonant and non-resonant processes ${e^ - }{e^ + } \to J/\psi \to \Lambda \bar \Lambda$ and ${e^ - }{e^ + } \to {\gamma ^\ast} \to \Lambda \bar \Lambda$ at $\sqrt s = 2.396\,{\rm{GeV}}$, respectively. For $J/\psi \to \Lambda \bar \Lambda$ the relative phase between the electric and magnetic form factors, ΔΦ, has for the first time been determined, $\Delta \Phi = 42.4{(6)_{{\rm{stat}}}}(5)_{_{{\rm{syst}}}}^^\circ$. That $\Delta \Phi \ne 0$ allows for a simultaneous measurement also of the asymmetry decay parameters $\Lambda \to p{\pi ^ - }\,({\alpha _ - })$, $\bar \Lambda \to \bar p{\pi ^ + }\,({\alpha _ + })$ and $\bar \Lambda \to \bar n{\pi ^0}\,({\bar \alpha _0})$. The measured value of ${\alpha _ - } = 0.750 \pm 0.009 \pm 0.004$ differs by 17(3)% from the PDG value. The simultaneous measurement for the asymmetry parameters allows for the most precise test of CP violation conducted for Λ decays, ACP = −0.006(12)stat(7)syst. The reaction ${e^ - }{e^ + } \to \Lambda \bar \Lambda$ at $\sqrt s = 2.396\,{\rm{GeV}}$ is the first complete measurement of the time-like electric (GE) and magnetic (GM) form factor of any baryon as also the ratio R = |(GE/(GM)| and ΔΦ have been determined: R = 0.96(14)(12) and $\Delta \Phi = 37{(12)_{{\rm{stat}}}}(6)_{{\rm{stat}}}^\circ$. The obtained cross-section and effective form factor are σ = 119.0(53)stat(51)syst pb and |G| = 0.123(3)stat(3)syst, respectively.

Elastic Longitudinal Electron Scattering form Factors of 9Be

2011 ◽  
Vol 14 (2) ◽  
pp. 116-122 ◽  
Author(s):  
R.A. Radhi ◽  
◽  
N.M. Adeeb ◽  
A.K. Hashim ◽  
◽  
...  
Keyword(s):  
Electron Scattering ◽  
Form Factors

Calculation of charge form factor of elastic electron scattering based on Skyrme force and relativistic eikonal approximation

2019 ◽  
Vol 28 (03) ◽  
pp. 1950015
Author(s):  
Xiaoyong Guo ◽  
Zaijun Wang ◽  
Tianjing Li ◽  
Jian Liu
Keyword(s):  
Electron Scattering ◽  
Mean Field ◽  
Form Factors ◽  
Eikonal Approximation ◽  
Skyrme Force ◽  
Elastic Electron ◽  
Elastic Electron Scattering ◽  
Charge Form ◽  
Relativistic Treatment ◽  
Rmf Model

We construct a scheme to calculate the charge form factors for the elastic electron scattering. Our calculation is based on the relativistic eikonal approximation and the Skyrme–Hartree–Fock equation. To perform our calculation and benchmark the results, eight model nuclei with available experimental data: [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] are considered. For the comparison, the charge form factors calculated by the relativistic mean-field (RMF) model are also provided. Parameter set SLy5 is utilized for the Skyrme force, and the set NL3 is applied for the RMF model. It has been confirmed that combining of a nonrelativistic treatment for the target nucleus with a relativistic treatment for the incident electron may work better to reach highly descriptive and predictive results similar to the pure relativistic treatment. The results of this work are also useful for future experiments to test different inputs of densities for a specific nucleus.

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