Parity-mixing below 30 MeV excitation energy in the 4He system

1980 ◽  
Vol 58 (2) ◽  
pp. 249-254
Author(s):  
J. J. Bevelacqua
Keyword(s):  
Matrix Element ◽  
Excitation Energy ◽  
Enhancement Factor ◽  
Neutral Current ◽  
Model Space ◽  
Wave Functions ◽  
Matrix Elements ◽  
Least Squares Fit ◽  
Mixing Matrix ◽  
Text Model

Parity-mixing matrix elements for ΔT = 0 and ΔT = 1 transitions are calculated for selected transitions below 30 MeV excitation energy in the 4He system. The effective potential of Box, McKellar, Pick, and Lassey is utilized in the calculations. The results are based on detailed 4He wave functions which are calculated in a [Formula: see text] model space. The calculated parity-mixing matrix elements are in qualitative agreement with those predicted on the basis of a least-squares fit to 2 ≤ A ≤ 181 data by Desplanques and Missimer. The ΔT = 0 matrix element is calculated between the (0+,0)20.1 MeV level and the (0−,0)21.1 MeV level, while the ΔT = 1 matrix element is evaluated between the (1+,0) 25.5 MeV level and the (1−,1) 27.4 MeV state. The ΔT = 0 and ΔT = 1 calculations lead to parity-mixing matrix elements of −0.014 and +0.049 eV, respectively. These matrix elements correspond to parity-mixed components which are 10−8 smaller than the dominant parity component of an energy level. The parity-non-conserving (PNC) transitions lead to circular polarizations of 1.2 × 10−7 for the (1+,0) 25.5 MeV level and −2.2 × 10−8 for the (1−,1) 27.4 MeV level. The inclusion of a neutral current enhancement factor of about 10 increases the ΔT = 1 parity-mixing matrix element by about a factor of two.

Parity-mixing above 30 MeV excitation energy in the 4He system

1981 ◽  
Vol 59 (6) ◽  
pp. 765-768
Author(s):  
J. J. Bevelacqua
Keyword(s):  
Excitation Energy ◽  
Effective Potential ◽  
Energy Levels ◽  
Model Space ◽  
Wave Functions ◽  
Order Of Magnitude ◽  
Text Model ◽  
Body Potential

Parity-induced circular polarizations have been calculated for energy levels between 30 and 90 MeV excitation energy in the 4He system. The effective potential of Box, McKellar, Pick, and Lassey (BMPL) is utilized in the calculations. The results are based on detailed 4He wave functions which are calculated in a [Formula: see text] model space. The calculated circular polarizations (Pγ) are largest for Jπ = 1+ states at about 75 MeV excitation. These Pγ values are between 10−5 and 10−6 and are of the same order of magnitude as transitions measured in the 2H, 181Ta, and 203Tl systems. Circular polarizations based on the BMPL potential are within 15% of the Pγ values derived from the weak two-body potential of Desplanques and Missimer for the largest transitions considered in this study.

CP Violation in SU(3) × U(1) Electroweak Model

1997 ◽  
Vol 12 (24) ◽  
pp. 4411-4424 ◽  
Author(s):  
Tae Hoon Lee ◽  
Dae Sung Hwang
Keyword(s):  
Cp Violation ◽  
Mass Matrix ◽  
Neutral Current ◽  
Tree Level ◽  
Additional Contribution ◽  
Matrix Elements ◽  
Mixing Angle ◽  
Mixing Matrix ◽  
Electroweak Model ◽  
New Phase

We study the charged and the neutral current interactions of quarks in an SU (3)L × U (1)X electroweak model. Based on the assumption that u-type quarks coincide with their mass eigenstates, we obtain a new mixing angle θ′ and another CP violating phase δ′ in the extra heavy quark sector besides the usual Kobayashi–Maskawa mixing matrix. This new phase δ′ does not effect a change in the mass matrix elements of the [Formula: see text] systems when θ′ is small, but extra heavy quarks and gauge bosons give rise to additional contribution to the real part of the off-diagonal mass matrix elements and then the CP violation parameter ε is modified. By requiring that the tree level FCNC does not have an important effect on the [Formula: see text] and [Formula: see text] mixings in this model, we obtain a new lower bound on the mass of the extra heavy neutral gauge boson as 1.8 TeV.

Avoided-crossing molecular-beam spectroscopy of symmetric tops. I. Phosphoryl fluoride (OPF3)

1981 ◽  
Vol 59 (1) ◽  
pp. 150-171 ◽  
Author(s):  
Irving Ozier ◽  
W. Leo Meert
Keyword(s):  
Dipole Moment ◽  
Molecular Beam ◽  
Wave Functions ◽  
Matrix Elements ◽  
Centrifugal Distortion ◽  
Electric Resonance ◽  
Avoided Crossing ◽  
Mixing Matrix ◽  
The Individual

A new avoided-crossing technique using a conventional molecular beam electric resonance spectrometer has been developed for studying symmetric rotors. By means of an external electric field, two levels with different values of K are made nearly degenerate and normally forbidden electric-dipole transitions between the interacting levels are observed. Mixing matrix elements ηST with ΔK = ± 3 arise from the centrifugal distortion dipole moment μD and mixing terms ηHYP, with ΔK = ± 1, ± 2 arise from the nuclear hyperfine Hamiltonian. Explicit expressions for ηHYP are given in an Appendix. Many of these terms break the symmetry of both the rotational and nuclear spin parts of the wave functions. The avoided-crossing method is discussed in detail, with emphasis on its application to the measurement of (A0–B0). It is shown how the technique can be used to determine the perpendicular moment μD, as well as μJ, and μK, the constants which characterize the dependence of the parallel dipole moment μ on J and K, respectively. Other applications include the experimental investigation of the selection rules for the individual terms in ηHYP and the determination of the sign of the rotational g-factors [Formula: see text] and [Formula: see text].∙The method has been applied to phosphoryl fluoride (OPF3). It has been determined that (A0–B0) = 217.4987(44) MHz, μD = 5.856(20) × 10−6 D, μJ = −3.38(10) × 10−6 D, and both [Formula: see text] and [Formula: see text] are negative.

scholarly journals Shell model calculations in the A ~ 100 mass region

2020 ◽  
Vol 6 ◽  
pp. 225
Author(s):  
P. Divari ◽  
L. D. Skouras
Keyword(s):  
Shell Model ◽  
Large Scale ◽  
Model Space ◽  
Mass Region ◽  
Matrix Elements ◽  
Model Calculations ◽  
Single Neutron ◽  
Least Squares Fit ◽  
The Matrix ◽  
Inert Core

The properties of nuclei with 39≤Ζ≤47 and Ν=51-52 are investigated in large scale shell-model calculations. The doubly closed nucleus 100Sn is selected as the reference state and the nuclei under examination are described in terms of proton holes and one up two neutrons outside the inert core. The proton holes are distributed in a model space consisting of the orbitals g9/2, p1/2, p3/2 while f5/2 is sometimes also considerd. Similary the model space for the neutron particles in­ cludes the orbitals g7/2, d5/2, d3/2, s1/2 and in certain cases h11/2. The effective two-body interaction and the matrix elements of the effective operators were deter­ mined by introducing second-order corrections to the Sussex matrix elements. The single proton holes as well as the single-neutron energies were treated as parameters which were determined by least-squares fit to the observed levels of 39≤Ζ≤47, Ν=50 and Ν=51 respectively. The results of the calculation were found to be in satisfactory agreement with experimental data and this enable us to make predictions about the properties of some exotic nuclei in the vicinity of 100Sn.

scholarly journals 3+ States of 8Be

1978 ◽  
Vol 31 (4) ◽  
pp. 239 ◽  
Author(s):  
FC Barker ◽  
Nasima Ferdous
Keyword(s):  
Matrix Element ◽  
Phase Shift ◽  
Excitation Energy ◽  
Cross Sections ◽  
Qualitative Agreement ◽  
Energy Difference ◽  
Mixing Model ◽  
R Matrix ◽  
Mixing Matrix ◽  
The Cross

Level parameters for the 3+ doublet at about 19 MeV in "Be are obtained from a two-level R-matrix fit to the 7Li+p 5P3 phase shift, using the restrictions of the two-state isospin mixing model. The energy of the lower level is appreciably below the accepted value. Predicted contributions from the 3 + levels to the cross sections for the reactions 7Li(p, n), 7Li(p, y), lOBed, ex) and 9Be(d, t) are compared with measured values, and qualitative agreement is obtained. The new values of the level parameters give agreement with values of the isospin mixing matrix element and of the excitation energy difference of the 3 +, T = 1 states in "Li and "Be, calculated assuming that the charge-dependent nteraction is purely Coulomb.

scholarly journals Shell model calculations in the A=90-98 mass region. A study of the N=51. nuclei

2020 ◽  
Vol 5 ◽  
pp. 90
Author(s):  
P. Divari ◽  
L. D. Skouras
Keyword(s):  
Shell Model ◽  
Large Scale ◽  
Model Space ◽  
Mass Region ◽  
Matrix Elements ◽  
Model Calculations ◽  
Single Neutron ◽  
Least Squares Fit ◽  
The Matrix ◽  
Inert Core

The properties of nuclei with 39 < Ζ < 47 and N=51 are investigated in large scale shell-model calculations. The doubly closed nucleus 100Sn is selected as the reference state and the nuclei under examination are described in terms of proton holes and a single neutron outside the inert core. The proton holes are distributed in a model space consisting of the orbitals g9/2, p1/2, p3/2 while f5/2 is sometimes also considerd. Similary the model space for the single neutron includes the orbitals g7/2, d5/2, d3/2, s1/2 and in certain cases h11/2. The effective two-body interaction and the matrix elements of the effective operators were determined by introducing second-order correctios to the Sussex matrix elements. The single proton holes as well as the single-neutron energies were treated as parameters which were determined by least-squares fit to the observed levels of 39 < Ζ < 47, N=50 and Ν=51 respectively. The results of the calculation were found to be in satisfactory agreement with experimental data and this enable us to make predictions about the properties of some exotic nuclei in the vicinity of 100Sn.

scholarly journals Dipole Moment Functions of HF and HI Molecules Using an Anharmonic Potential

1983 ◽  
Vol 38 (1) ◽  
pp. 16-19 ◽  
Author(s):  
Manfred H. Kluckner ◽  
B. Sesh Rao
Keyword(s):  
Wave Equation ◽  
Dipole Moment ◽  
Electric Dipole ◽  
Wave Functions ◽  
Matrix Elements ◽  
Least Squares Fit ◽  
Anharmonic Potential ◽  
The Matrix ◽  
Moment Functions ◽  
Vibration Rotation

Abstract Vibration-rotation wave functions for HF and HI are computed by solving the radial Schroedinger wave equation numerically using an anharmonic potential function with seven adjustable parameters. With these wave functions the matrix elements of [(r - re)/re]n are computed. These are then applied in a least squares fit to experimentally measured values of the electric dipole matrix elements to yield the dipole moment coefficients M0, M1,..., M5 .

scholarly journals Current and future neutrino oscillation constraints on leptonic unitarity

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Sebastian A. R. Ellis ◽  
Kevin J. Kelly ◽  
Shirley Weishi Li
Keyword(s):  
Precise Measurement ◽  
Sterile Neutrino ◽  
Current Knowledge ◽  
Unknown Origin ◽  
Neutrino Masses ◽  
Matrix Elements ◽  
Neutrino Mixing ◽  
Next Generation ◽  
Active Neutrino ◽  
Mixing Matrix

Abstract The unitarity of the lepton mixing matrix is a critical assumption underlying the standard neutrino-mixing paradigm. However, many models seeking to explain the as-yet-unknown origin of neutrino masses predict deviations from unitarity in the mixing of the active neutrino states. Motivated by the prospect that future experiments may provide a precise measurement of the lepton mixing matrix, we revisit current constraints on unitarity violation from oscillation measurements and project how next-generation experiments will improve our current knowledge. With the next-generation data, the normalizations of all rows and columns of the lepton mixing matrix will be constrained to ≲10% precision, with the e-row best measured at ≲1% and the τ-row worst measured at ∼10% precision. The measurements of the mixing matrix elements themselves will be improved on average by a factor of 3. We highlight the complementarity of DUNE, T2HK, JUNO, and IceCube Upgrade for these improvements, as well as the importance of ντ appearance measurements and sterile neutrino searches for tests of leptonic unitarity.

Strange matrix elements in the proton from neutral-current experiments

1988 ◽  
Vol 310 (3-4) ◽  
pp. 527-547 ◽  
Author(s):  
David B. Kaplan ◽  
Aneesh Manohar
Keyword(s):  
Neutral Current ◽  
Matrix Elements
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