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The Influence of the NN* Channel on Elastic NN Scattering


Shepard, Harvey Kenneth (1966) The Influence of the NN* Channel on Elastic NN Scattering. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/5HRF-4A20.


The problem of two channels NN and NN*, coupled through unitarity, is studied to see whether sizable peaks can be produced in elastic nucleon-nucleon scattering due to the opening of a strongly coupled inelastic channel. One-pion-exchange (OPE) interactions are calculated to estimate the NN*→NN* and NN→NN* amplitudes. The OPE production amplitudes are used as the sole dynamical input to drive the multichannel ND-1 equations in the determinental approximation, and the effect on the J = 2+ (1D2) elastic NN scattering amplitude is studied as the width of the unstable N* and strength of coupling to the inelastic channel are varied. A cusp-type enhancement appears in the NN channel near the NN* threshold but for the known value of the N* width the cusp is so “wooly” that any resulting elastic peak is likely to be too broad and diminished in height to be experimentally prominent. A brief survey of current experimental knowledge of the real part of the 1D2 NN phase shift near the NN* threshold is given, and the values are found to be much smaller than the nearly “resonant” phase shifts predicted by the coupled channel model.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Physics)
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Frautschi, Steven C.
Thesis Committee:
  • Unknown, Unknown
Defense Date:14 December 1965
Funding AgencyGrant Number
Atomic Energy CommissionUNSPECIFIED
Record Number:CaltechTHESIS:10192015-090318183
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9225
Deposited On:19 Oct 2015 20:25
Last Modified:08 Mar 2024 00:25

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