[Triumf-seminars] TRIUMF Seminar today at 14:00

[postmaster at admin.triumf.ca]

Date/Time: Thu 2011-02-17 at 14:00

Location:  Auditorium          

Speaker:   Byron Jennings (TRIUMF)

Title:     Spectroscopic Factors and All That

Abstract: The spectroscopic factor is not invariant under unitary transformations of the many-body wave function. As an example of this degree of freedom, traditional nucleon-nucleon potentials with strong short-range repulsion generate lower spectroscopic factors than the modern soft potentials like VlowK. If spectroscopic factors were measurable then it would be possible to differentiate between the traditional potentials and Vlowk or determine the Vlowk cutoff. The cutoff, by construction, has no observable consequences.  By the considering the case of radiative capture (or photo-disintegration), I will show explicitly how to arbitrarily vary the spectroscopic factor extracted from experiment by varying the nuclear potentials through a field redefinition. Thus it can be made to agree with that calculated using any model of the NN potential. The field redefinitions considered are consistent with those  generated by unitary transformations of the many-body wave function, however there does not appear to be any simple relation between the field redefinition and the cut-off in Vlowk. The arbitrariness of the spectroscopic factor implies that it is not a useful meeting ground between theory and experiment.

Stimulants available 15 minutes before the talk.

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