Nuclear reactions reduced width

The lithium plus proton reactions thus exhibit many characteristic features of nuclear reactions as a whole, namely the existence of sharply defined resonant states from which particle break-up is prohibited, the probable influence of direct transitions not involving a compound state, the existence of very broad states constituting a background with which interference can take place in many reactions, the description of the levels by the Breit-Wigner formula, and the implications of the principle of charge independence. The information obtainable on the reduced widths and quantum numbers of the states of Be is discussed in the light of nuclear models in Sect. 76. 

The reduced widths and parity for formation of ground states confirm the sequence of single particle orbits proposed by the nuclear shell model (Sect, 3, and Bethe and Butler ). Excited states of a given nucleus which have nucleon capture probabilities comparable with that found for the ground state may be interpreted as single particle states. Comparison of capture probabilities in dp) and dn) reactions may indicate the first state of T — in a nucleus of r = 0 (see AF , Sect. 52). The relative capture probabilities or reduced widths for two different nuclear states (preferably with the same Q can be used (Auerbach and French ) to determine the intermediate coupling parameter ajK (Sect. 3 and [10 ]). 

Lane, A. M., and R. G. Thomas The Theory of Nuclear Reactions and the Compound Nucleus. Rev. Mod. Phys. to be published in 1957. — A very full treatment of the dispersion theory of nuclear reactions, particularly valuable for its treatment of reaction constants in various coupling schemes. Comparison with experimental information is made also Lane, A. M. The reduced widths of nuclear energy levels, A.E.R.E. Report T/R1289 (1954). (United Kingdom Atomic Energy Authority.)... 

A similar change from 9 to 5 lines results sometimes when a simple salt with a common cation is added. In this case reaction (3.2) occurs, so that the lifetimes of the asymmetric units are reduced, but different sodium ions (with varying nuclear spins) are involved, so that the cation hyperfine splitting is lost at the same rate. As usual, at intermediate rates, lines become broad and from the width increments, rates and activation energies and entropies can be obtained. 

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