WEAK GAMMA-RAY TRANSITIONS IN 20Ne

1967 ◽  
Vol 45 (12) ◽  
pp. 3836-3847
Author(s):  
C. Broude ◽  
A. E. Litherland ◽  
R. W. Ollerhead ◽  
T. K. Alexander
Keyword(s):  
Angular Correlation ◽  
Ground State ◽  
Gamma Ray ◽  
Decay Modes ◽  
Total Level ◽  
Level Width ◽  
Weak Transitions

Various techniques have been applied to the measurement of weak gamma-ray decay modes of the 4.97-MeV 2− and 7.02-MeV 4− states in 20Ne excited by the reaction 12C(12C, αγ)20Ne. The M2 decay of the 4.97-MeV state to the ground state is 0.6 ± 0.2% of the total level width, corresponding to an M2 width of 2 × 10−3 Weisskopf units. The M2–E3 transition from the 7.02-MeV state to the 1.63-MeV 2+ state is 0.5% ± 0.2% of the level width; if all M2, this would correspond to an inhibition of 1.4 × 10−2 Weisskopf units, if all E3, to an enhancement of 6 Weisskopf units. The reliability of the measurements has been checked by angular correlation measurements of the weak transitions.

Study of levels in 24Mg

1968 ◽  
Vol 46 (12) ◽  
pp. 1381-1401 ◽  
Author(s):  
R. W. Ollerhead ◽  
J. A. Kuehner ◽  
R. J. A. Levesque ◽  
E. W. Blackmore
Keyword(s):  
Angular Correlation ◽  
Beta Decay ◽  
Rotational Band ◽  
Ground State ◽  
Present Experiment ◽  
Gamma Ray ◽  
Axially Symmetric ◽  
Excitation Energies ◽  
Rotational Model ◽  
Rotational Bands

Nineteen levels in 24Mg have been studied utilizing the reaction 12C(16O, αγ)24Mg. Angular correlation measurements have established the spins and parities of levels at excitation energies of 7.35, 7.56, 7.62, 8.44, 8.65, 9.00, 9.15, and 10.1 MeV as 2+, 1−, 3−, 1−, 2+, 2+, 1−, and 0+ respectively. Levels at 8.12 and 13.18 MeV have been identified as the 6+ and 8+ members of the K = 0 ground-state rotational band; levels at 7.81 and 9.52 MeV have been identified as the 5+ and 6+ members of the K = 2 rotational band based on the 2+ level at 4.23 MeV. The existence of doublets has been established at excitation energies of 8.44 and 9.52 MeV; in each case, one member of the doublet is populated in the beta decay of 24Al, and the present experiment indicates that these two levels have spin and parity 4+. Assignments are also suggested for levels at 7.75 MeV (1+) and 8.36 MeV (2+). Gamma-ray spectra have been obtained for levels at 8.86, 9.28, and 9.46 MeV. The properties of levels assigned to rotational bands are compared to the predictions of the rotational model for an axially symmetric nucleus.

scholarly journals Multipolarity of the2−→1−, ground-state transition inBi210via multivariable angular correlation analysis

2016 ◽  
Vol 94 (1) ◽  
Author(s):  
N. Cieplicka-Oryńczak ◽  
B. Szpak ◽  
S. Leoni ◽  
B. Fornal ◽  
D. Bazzacco ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Angular Correlation ◽  
Ground State ◽  
State Transition ◽  
Ground State Transition

Some neutron-gamma ray angular correlation studies of 29P

1970 ◽  
Vol 141 (1) ◽  
pp. 33-66 ◽  
Author(s):  
J.M. Calvert ◽  
T. Joy
Keyword(s):  
Angular Correlation ◽  
Gamma Ray ◽  
Correlation Studies

Level width of the ground state of B9

1964 ◽  
Vol 9 (2) ◽  
pp. 157-159 ◽  
Author(s):  
E. Teranishi ◽  
B. Furubayashi
Keyword(s):  
Ground State ◽  
Level Width

High-Purity Germanium Technology for Gamma-Ray and X-Ray Spectroscopy

1993 ◽  
Vol 302 ◽  
Author(s):  
L.S. Darken ◽  
C. E. Cox
Keyword(s):  
Cross Section ◽  
Gamma Rays ◽  
Ground State ◽  
High Purity ◽  
Gamma Ray ◽  
Capture Rate ◽  
X Rays ◽  
Hole Capture ◽  
High Purity Germanium ◽  
Energy Gamma

ABSTRACTHigh-purity germanium (HPGe) for gamma-ray spectroscopy is a mature technology that continues to evolve. Detector size is continually increasing, allowing efficient detection of higher energy gamma rays and improving the count rate and minimum detectable activity for lower energy gamma rays. For low-energy X rays, entrance window thicknesses have been reduced to where they are comparable to those in Si(Li) detectors. While some limits to HPGe technology are set by intrinsic properties, the frontiers have historically been determined by the level of control over extrinsic properties. The point defects responsible for hole trapping are considered in terms of the “standard level” model for hole capture. This model originates in the observation that the magnitude and temperature dependence of the cross section for hole capture at many acceptors in germanium is exactly that obtained if all incident s-wave holes were captured. That is, the capture rate is apparently limited by the arrival rate of holes that can make an angular-momentum-conserving transition to a s ground state. This model can also be generalized to other materials, where it may serve as an upper limit for direct capture into the ground state for either electrons or holes. The capture cross section for standard levels σS.L. is given bywhere g is the degeneracy of the ground state of the center after capture, divided by the degeneracy before capture. Mc is the number of equivalent extrema in the band structure for the carrier being captured, mo is the electronic mass, m* is the effective mass, and T is the temperature in degrees Kelvin.

NON-LEPTONIC WEAK TRANSITIONS WITH ΔI = 1/2 RULE IN DIQUARK-QUARK MODEL USING THE PAULI-GÜRSEY SYMMETRY

1994 ◽  
Vol 09 (12) ◽  
pp. 1059-1069 ◽  
Author(s):  
K. SUZUKI ◽  
H. TOKI
Keyword(s):  
Quark Model ◽  
Ground State ◽  
Wave Functions ◽  
P Wave ◽  
Standard Process ◽  
Weak Process ◽  
Pion Emission ◽  
Spin Singlet ◽  
Weak Transitions

We study the non-leptonic weak transitions of ground state baryons in diquark-quark model. These weak transitions exhibit the ΔI = 1/2 rule, which is hard to account for in the standard weak process. If the diquark correlations are strong among flavor-antitriplet and spin-singlet pairs, we can make the weak transitions among diquarks followed by pion emission much stronger than the standard process. We estimate all the non-leptonic weak transitions of ground state baryons by assuming the Pauli-Gürsey symmetry together with the SU(6) wave functions. We can account for all the P-wave transition strengths quantitatively and hence the ΔI = 1/2 rule.

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