Sum rules and mean excitation energies for longitudinal isoscalar electroexcitation of nuclei

1977 ◽  
Vol 16 (2) ◽  
pp. 812-815 ◽  
Author(s):  
E. Lipparini ◽  
G. Orlandini ◽  
R. Leonardi
Keyword(s):  
Sum Rules ◽  
Excitation Energies

scholarly journals SUM RULES AND MOMENTS OF THE NUCLEON SPIN STRUCTURE FUNCTIONS

2005 ◽  
Vol 20 (36) ◽  
pp. 2745-2765 ◽  
Author(s):  
J.-P. CHEN ◽  
A. DEUR ◽  
Z.-E. MEZIANI
Keyword(s):  
Momentum Transfer ◽  
Spin Structure ◽  
Sum Rules ◽  
Structure Functions ◽  
Operator Product ◽  
Asymptotic Freedom ◽  
Nucleon Spin ◽  
Excitation Energies ◽  
Nucleon Spin Structure ◽  
Spin Structure Functions

The nucleon has been used as a laboratory to investigate its own spin structure and quantum chromodynamics. New experimental data on nucleon spin structure at low to intermediate momentum transfers combined with existing high momentum transfer data offer a comprehensive picture of the transition region from the confinement regime of the theory to its asymptotic freedom regime. Insight for some aspects of the theory is gained by exploring lower moments of spin structure functions and their corresponding sum rules (i.e. the Gerasimov–Drell–Hearn, Bjorken and Burkhardt–Cottingham). These moments are expressed in terms of an operator-product expansion using quark and gluon degrees of freedom at moderately large momentum transfers. The sum rules are verified to good accuracy assuming that no singular behavior of the structure functions is present at very high excitation energies. The higher-twist contributions have been examined through the moments evolution as the momentum transfer varies from higher to lower values. Furthermore, QCD-inspired low-energy effective theories, which explicitly include chiral symmetry breaking, are tested at low momentum transfers. The validity of these theories is further examined as the momentum transfer increases to moderate values. It is found that chiral perturbation calculations agree reasonably well with the first moment of the spin structure function g1 at momentum transfer of 0.1 GeV2 but fail to reproduce the neutron data in the case of the generalized polarizability δLT.

Nuclear muon-capture sum rules and mean nuclear excitation energies

1974 ◽  
Vol 10 (5) ◽  
pp. 2034-2044 ◽  
Author(s):  
B. Goulard ◽  
H. Primakoff
Keyword(s):  
Sum Rules ◽  
Muon Capture ◽  
Nuclear Excitation ◽  
Excitation Energies

A Perturbation Theory for the Population of Atomic Energy Levels in Non-Lte Plasmas

1988 ◽  
Vol 102 ◽  
pp. 343-347
Author(s):  
M. Klapisch
Keyword(s):  
Perturbation Theory ◽  
Small Parameter ◽  
Classification Scheme ◽  
Sum Rules ◽  
Energy Levels ◽  
Natural Classification ◽  
Quantum Numbers ◽  
Formal Expansion ◽  
Atomic Energy Levels ◽  
As Effects

AbstractA formal expansion of the CRM in powers of a small parameter is presented. The terms of the expansion are products of matrices. Inverses are interpreted as effects of cascades.It will be shown that this allows for the separation of the different contributions to the populations, thus providing a natural classification scheme for processes involving atoms in plasmas. Sum rules can be formulated, allowing the population of the levels, in some simple cases, to be related in a transparent way to the quantum numbers.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

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