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Applications of effective field theory to electron scattering

Citation

Diaconescu, Luca Radu (2005) Applications of effective field theory to electron scattering. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-03082005-201156

Abstract

In this work two calculations are presented. In the first, we compute the vector analyzing power (VAP) for the elastic scattering of transversely polarized electrons from protons at low energies, using an effective theory of electrons, protons, and photons. We study all contributions through second order in E/M, where E and M are the electron energy and nucleon mass, respectively. The leading order VAP arises from the imaginary part of the interference of one- and two-photon exchange amplitudes. Sub-leading contributions are generated by the nucleon magnetic moment and charge radius, as well as recoil corrections to the leading-order amplitude. Working to second order in E/M), we obtain a prediction for $A_n$ that is free of unknown parameters and that agrees with the recent measurement of the VAP in backward angle electron proton scattering.

In the second part of this thesis the longitudinal asymmetry due to Z exchange is calculated in quasi-elastic electron-deuteron scattering at momentum transfers |Q^2| of about 0.1 GeV^2 relevant for the SAMPLE experiment. The deuteron and $pn$ scattering-state wave functions are obtained from solutions of a Schrodinger equation with the Argonne v18 potential. Electromagnetic and weak neutral one- and two-nucleon currents are included in the calculation. The two-nucleon currents of pion range are shown to be identical to those derived in Effective Field Theory. The results indicate that two-body contributions to the asymmetry are small (about 0.2%) around the quasi-elastic peak, but become relatively more significant (about 3%) in the high-energy wing of the quasi-elastic peak.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:effective field theory; electron scattering
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • McKeown, Robert D. (advisor)
  • Ramsey-Musolf, Michael J. (advisor)
  • van Kolck, Ubirajara (advisor)
Thesis Committee:
  • McKeown, Robert D. (chair)
  • Wise, Mark B.
  • Ramsey-Musolf, Michael J.
  • van Kolck, Ubirajara
Defense Date:7 January 2005
Author Email:luca (AT) its.caltech.edu
Record Number:CaltechETD:etd-03082005-201156
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-03082005-201156
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:897
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:17 Mar 2005
Last Modified:26 Dec 2012 02:33

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