An isospin-mixed triplet in 44Ti

1980 ◽  
Vol 58 (9) ◽  
pp. 1360-1366 ◽  
Author(s):  
W. R. Dixon ◽  
R. S. Storey ◽  
J. J. Simpson
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Gamma Ray ◽  
Branching Ratios ◽  
Proton Decay ◽  
The Other ◽  
Angular Distributions ◽  
Matrix Elements ◽  
Quantitative Estimates

Three levels in 44Ti at energies of 9215 ± 2, 9227 ± 2, and 9239 ± 2 keV have been studied in the 40Ca(α,γ) reaction. Gamma-ray branching ratios, angular distributions, and transition strengths have been measured for each level. Proton decay strengths have also been determined. Each level is assigned Jπ = 2+. The level at 9227 keV must be predominantly T = 1 because of its strong M1 decays, while the other two levels are believed to be predominantly T = 0 because of their stronger E2 transitions to the ground state. Treating the three levels as an isospin-mixed triplet gives a consistent interpretation for all the experimental data, and allows quantitative estimates to be made of the amount of isospin mixing and of the magnitude of the isovector matrix elements.

Study of the Ep = 1.724 MeV Resonance in the 27Al(p, γ) 28Si Reaction

1971 ◽  
Vol 49 (6) ◽  
pp. 685-703 ◽  
Author(s):  
S. T. Lam ◽  
A. E. Litherland ◽  
R. E. Azuma
Keyword(s):  
Ground State ◽  
Gamma Ray ◽  
Branching Ratios ◽  
Thick Target ◽  
Angular Distributions ◽  
Transition Strength ◽  
Proton Capture ◽  
A Value ◽  
28Si Reaction ◽  
Relative Measurements

The 13.245 MeV level in 28Si has been populated by resonant proton capture at 1.724 MeV in the 27Al(p,γ)28Si reaction. Gamma-ray angular distributions and linear polarizations have been measured respectively with a coaxial and a planar Ge(Li) counter. Branching ratios have been extracted from the angular distributions. Spins have been assigned to the levels of 28Si with the help of the angular distribution and linear polarization results. The spin and parity of the 13.245 and 9.699 MeV levels are most probably 5− with T = 1 and 0 respectively. The assignment Jπ = 4− for the 8.411 MeV level is in agreement with the present data. A spin and parity of 3− for both the 13.245 and 9.699 MeV levels also fits the data but with more adjustable parameters. Arguments are presented to show that these assignments are unlikely. Relative measurements of the gamma-ray yields from a thick target give a value of (7.5 ± 1.5) eV for (2J + 1)ΓγΓp/Γ of the resonance. The M1 transition strength between the 13.245 and the 9.699 MeV levels is then deduced to be (0.7 ± 0.15) W.u. The known properties of the 9.699 MeV level suggest that it may be associated with an E5 oscillation of the ground state of 28Si.

The (K−,π−) and (π+, K+) Reactions and Λ-Hypernuclear Polarization

1994 ◽  
Vol 117 ◽  
pp. 17-53 ◽  
Author(s):  
K. Itonaga ◽  
T. Motoba ◽  
M. Sotona
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Cross Sections ◽  
Ground State ◽  
Weak Decay ◽  
Angular Distributions ◽  
Theoretical Studies ◽  
Excitation Functions ◽  
Unnatural Parity ◽  
Natural Parity

The theoretical studies of (K−, π−) and (π+, K+) reactions on p-shell targets are presented in the DWIA framework with use of the elementary spin-nonflip and spin-flip amplitudes. Calculations can explain the available experimental data of excitation functions and angular distributions of the (K−, π−) reactions at pK−=800 MeV/c and the (π+, K+) reactions at pπ+ = 1.04 GeV/c. Characteristic and distinguished features of the excitation functions and cross sections are exhibited. Especially it is demonstrated that the (K−, π−) reactions at pK−=1.1 GeV/c and 1.5 GeV/c can excite the unnatural parity states with comparable strength to the natural parity ones. Further interesting is that the (π+, K+) and (K−, π−) reactions with ∼1 GeV/c incident beams can be shown to produce very large polarizations of the produced hypernuclear states. Taking the subsequent deexcitation processes of the excited states into account, we have evaluated the hypernuclear polarization and Λ-spin polarization of the ground state and/or the ground-doublet states at the hypernuclear weak-decay stage, which would play a role in the hypernuclear coincidence experiment.

Proton?Capture Gamma Rays from Nitrogen?13

1962 ◽  
Vol 15 (3) ◽  
pp. 443 ◽  
Author(s):  
AW Parker ◽  
GG Shute
Keyword(s):  
Angular Distribution ◽  
Excited State ◽  
Elastic Scattering ◽  
Gamma Rays ◽  
Ground State ◽  
Recent Experiment ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Proton Capture ◽  
Yield Curves

From a recent experiment in this laboratory (Shute et al. 1962) on the elastic scattering of protons from 12C, resonance levels (E13N, J1t) of 13N were obtained at the laboratory bombarding energies (Ep) shown in Table 1. To confirm these results, an investigation of the yield and angular distribution of gamma rays from the reaction 12C(p'YO)13N and 12C(p'Yl)13N was undertaken. Accordingly, the theoretical angular distributions, W(8), for the gamma ray (Yo) to the ground state of 13Na-) and also for the gamma ray (Yl) to the 1st excited state of 13Na+) were evaluated on the assumptions that overlap of levels in 13N is small and lowest order multipoles are involved. As angular distributions are parity insensitive, these were found to be identical for the two gamma rays expected. The simpler of these angular distributions are also shown on the table. The expected angular distributions indicate that 90� is a suitable angle for yield curves.

NEW RESULT OF DIRECT CP VIOLATION IN B → π+π-π+π-

2011 ◽  
Vol 26 (17) ◽  
pp. 2899-2912 ◽  
Author(s):  
GANG LÜ ◽  
ZHEN-HUA ZHANG ◽  
XIU-YING LIU ◽  
LI-YING ZHANG
Keyword(s):  
Experimental Data ◽  
Cp Violation ◽  
Invariant Mass ◽  
Branching Ratios ◽  
Effective Parameter ◽  
Matrix Elements ◽  
Strong Constraint ◽  
Ckm Matrix ◽  
First Order ◽  
Isospin Violation

In the framework of factorization, based on the first-order of isospin violation, we study direct CP violation in the decay of [Formula: see text] including the effect of ρ–ω mixing. The CP violation depends strongly on Cabibbo–Kobayashi–Maskawa (CKM) matrix elements and the effective parameter, Nc. Recently, the experimental data for the branching ratios of [Formula: see text] are accurate and we can give the strong constraint on the range of Nc. We find that the CP violating asymmetry is large and ranges from -82% to -98% via ρ–ω mixing mechanism when the invariant mass of the π+π- pair is in the vicinity of the ω resonance. We also discuss the possibility to observe the predicted CP violating asymmetries at the LHC.

scholarly journals Study on branching ratios and direct CP asymmetries of D → PV decays

2014 ◽  
Vol 29 ◽  
pp. 1460209 ◽  
Author(s):  
Qin Qin ◽  
Hsiang-Nan Li ◽  
Cai-Dian Lü ◽  
Fu-Sheng Yu
Keyword(s):  
Experimental Data ◽  
Pseudoscalar Meson ◽  
Short Distance ◽  
D Mesons ◽  
Branching Ratios ◽  
Matrix Elements ◽  
Long Distance ◽  
Global Fit ◽  
Belle Ii ◽  
Cp Asymmetries

We study the non-leptonic two-body decays of D mesons decaying into one pseudoscalar meson (P) and one vector meson (V) in the factorization-asisted topological-amplitude approach. In this approach, the decay amplitudes are factorized into two parts, the short-distance contribution (Wilson coefficients) and the long-distance contribution (hadronic matrix elements). We predict the branching ratios of D → PV decays using a global fit with the non-perturbative parameters. Our results agree well with the experimental data. We also predict the direct CP asymmetries by combining short-distance dynamics associated with penguin operators and long-distance hadronic matrix elements determined by branching ratios. The large asymmetries in D+ → π+ρ0 and [Formula: see text] may be measurable in the LHCb and future Belle II experiments.

Study of Electromagnetic Multipole Transition Half-Lives of One-Hole 15O–15N and One-Particle 17O–17F Mirror Nuclei

2013 ◽  
Vol 68 (10-11) ◽  
pp. 709-714 ◽  
Author(s):  
Mohammadreza Pahlavani ◽  
Behnam Firoozi
Keyword(s):  
Experimental Data ◽  
Wave Functions ◽  
The Other ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Matrix Elements ◽  
Saxon Potential ◽  
N Isotopes ◽  
The One ◽  
Theoretical Results

Energy spectrum and wave functions are obtained numerically with a potential consisting of Woods-Saxon, Coulomb, and spin-orbit coupling parts for the nuclei 15O, 15N, 17O, and 17F. The radial parts of the wave functions are used to calculate some matrix elements of electromagnetic transitions. These results are applied to calculate half-lives of low-lying exited states in the one-particle 17O and 17F as well as in the one-hole 15O and 15N isotopes. The calculated half-lives are compared with available experimental and theoretical results based on harmonic oscillator wave functions and Weisskopf units. In comparison with the results calculated from the other methods, our results based on the Woods-Saxon potential indicate a satisfactory agreement with accessible experimental data.

Study of the Decay of the 3.696 MeV Level in 25Al

1971 ◽  
Vol 49 (4) ◽  
pp. 467-474 ◽  
Author(s):  
G. J. McCallum ◽  
R. J. Sparks ◽  
G. E. Coote ◽  
K. P. Pohl
Keyword(s):  
Doppler Shift ◽  
Gamma Ray ◽  
Branching Ratios ◽  
Angular Distributions ◽  
Doppler Shift Attenuation ◽  
Doppler Shift Attenuation Method

The decay of the 3.696 MeV level in 25Al has been studied by means of the 24Mg(p,γ)25Al reaction at the 1.49 MeV resonance. Gamma-ray branching ratios, direct angular distributions, and lifetimes determined by the Doppler shift attenuation method are reported.

ALPHA-DECAYS TO MEMBERS OF GROUND-STATE ROTATIONAL BAND OF HEAVY EVEN-EVEN NUCLEI

2008 ◽  
Vol 17 (supp01) ◽  
pp. 29-36 ◽  
Author(s):  
CHANG XU ◽  
ZHONGZHOU REN
Keyword(s):  
Experimental Data ◽  
Angular Momentum ◽  
Rotational Band ◽  
Ground State ◽  
Daughter Nucleus ◽  
Branching Ratios ◽  
Decay Energy ◽  
Α Decay ◽  
Barrier Penetration ◽  
Excitation Probability

We apply a simple barrier penetration approach to calculate α-decay branching ratios to members of ground-state rotational band of heavy even-even nuclei. The influence of α-decay energy, the angular momentum of α-particle, and the excitation probability of the daughter nucleus is taken into account in our calculations. The theoretical branching ratios of α-transitions are found to agree with the available experimental data well.

14.—Ground State Rotational Bands in 158Dy, 160Dy and 162Dy

1972 ◽  
Vol 70 ◽  
pp. 155-163 ◽  
Author(s):  
G. T. Ewan ◽  
G. I. Andersson
Keyword(s):  
Gamma Rays ◽  
Ground State ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Rotational Bands ◽  
Weak Evidence ◽  
Gamma Coincidence ◽  
Inertia Model ◽  
Coincidence Spectra ◽  
Variable Moment

SynopsisLevels in the ground state bands of 158Dy, 160Dy and 162Dy have been populated by (α, 2n) reactions on metallic targets of separated 156Gd, 158Gd and 160Gd isotopes. Two Ge(Li) detectors were used to study singles gamma-ray spectra, gamma-ray angular distributions, gamma-gamma coincidence spectra and relative yields of gamma-rays for bombarding energies from 20 to 27 MeV. Transitions from all levels in the ground state bands up to the 12+ member were identified and the following level energies in keV established: 158Dy: 0 (0+), 99·0 (2+), 317·4 (4+), 637·9 (6+), 1044·1 (8+), 1520·1 (10+) and 2049·4 (12+); 160Dy: 0 (0+), 86·7 (2+), 283·7 (4+), 581·4 (6+), 967·4 (8+), 1429·0 (10+), 1951·7 (12+); 162Dy: 0 (0+), 80·7 (2+), 265·7 (4+), 548·5 (6+), 921·1 (8+), 1374·8 (10+) and 1901·0 (12+). There is weak evidence for the 14+ levels in 158Dy and 160Dy. The level energies are compared with calculated values using the variable moment of inertia model.

PROPERTIES OF LEVELS AT 6.69 AND 6.88–6.89 MeV IN 28Si

1966 ◽  
Vol 44 (5) ◽  
pp. 1087-1097 ◽  
Author(s):  
R. J. A. Levesque ◽  
R. W. Ollerhead ◽  
E. W. Blackmore ◽  
J. A. Kuehner
Keyword(s):  
Excited State ◽  
Alpha Particle ◽  
Ground State ◽  
State Transition ◽  
Gamma Ray ◽  
The Other ◽  
Ground State Transition ◽  
Angular Correlations ◽  
First Excited State ◽  
Strong Ground

Levels at 6.69, 6.88, and 6.89 MeV were observed in the 16O(16O, α)28Si reaction, and angular correlations were measured for the resulting gamma-ray transitions, using the geometry in which the alpha particle is detected at 0°. The level at 6.69 MeV had not been reported previously and was assigned spin and parity 0+. The doublet of levels at 6.88–6.89 MeV was not resolved in these measurements, but angular correlations of the gamma-ray transitions were possible, using spectrum subtraction techniques. One member of the doublet, previously assigned spin 3, has a strong ground-state transition; the angular correlation for this transition confirms a 3− assignment to this level. The other member of the doublet, which decays almost entirely to the first excited state, could not be assigned a spin on the basis of these measurements. However, taken in conjunction with other measurements, an assignment of 4+ is favored.

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