A Caltech Library Service

Polarization of Recoil Protons from the Photoproduction of Neutral Pions in Hydrogen at 585 and 660 Mev.


Maloy, John Owen (1961) Polarization of Recoil Protons from the Photoproduction of Neutral Pions in Hydrogen at 585 and 660 Mev. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/418S-MZ02.


NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The polarization of the recoil proton in the photoproduction process [...] has been measured at laboratory photon energies of 585 and 660 Mev, at pion center-of-mass angles of 86 and 77 degrees respectively. Nuclear emulsion was used as a scatterer and detector to analyze the polarization of magnetically selected recoil protons emitted from a liquid hydrogen target. The target was bombarded by bremsstrahlung and electrons from the Stanford Mark III Linear Accelerator. The emulsion was area-scanned for scattering events; no evidence of left-right scanning bias was found. The polarization was calculated from the observed scattering distributions by the method of maximum likelihood, using values of the analyzing power of emulsion obtained at Harwell. Large polarizations were found, 56 ± 14 per cent at 585 Mev and 58 ± 19 per cent at 660 Mev; the 660 Mev value becomes 51 ± 14 per cent if events found in scanning by different methods at Rome and at Padua are included. The polarization is in the direction k x p, where k and p are the momentum vectors of the incident photon and recoil proton, respectively. The results are in agreement with measurements made elsewhere. It is shown that the polarizations and angular distributions observed in this reaction are consistent with the choice of odd parity for the second pion resonance, but are not consistent with the choice of even parity.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Physics and Mathematics)
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Minor Option:Mathematics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Peterson, Vincent Zetterberg (advisor)
  • Walker, Robert Lee (advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1961
Record Number:CaltechETD:etd-05052005-154404
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1622
Deposited By: Imported from ETD-db
Deposited On:05 May 2005
Last Modified:21 Nov 2023 17:20

Thesis Files

PDF (Maloy_jo_1961.pdf) - Final Version
See Usage Policy.


Repository Staff Only: item control page