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A Study of the Reactions π^±p → π^±π^+π^-π^op and π^±p → π^±π^+π^+π^-n at P_(lab) = 14 GeV/c Using a Triggered Hybrid Bubble Chamber


Nagy, Frank Joseph (1980) A Study of the Reactions π^±p → π^±π^+π^-π^op and π^±p → π^±π^+π^+π^-n at P_(lab) = 14 GeV/c Using a Triggered Hybrid Bubble Chamber. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/q42m-vd27.


We have studied the reactions π±p → π±π+π-πop and π±π+π+π-n at a beam momentum of 14 GeV/c. A bubble chamber with a downstream wire spark chamber spectrometer was used to record the data. The bubble chamber camera was triggered by identifing inelastic events in an online computer using data from the downstream spectrometer. The film taken represents an exposure of about 80 events/microbarn for the π+ data and 70 events/microbarn for the π- data.

We find these reactions to be very rich in subprocesses involving baryon and meson resonances. The invariant mass spectra are presented and estimates of the cross sections for the production of known baryon and meson resonances are given.

The reactions π±p → π±ωop provided more evidence for the existence of an N* resonance with mass 1789±5 MeV and width 81±9 MeV which decays into ωop. Using previously published data along with our results, we find that the production cross section of this N* is independent of s. Studies of the angular distributions raise questions about the validity of the spin-parity analyses of this N* done so far.

We have studied the processes π±p → π±ηop in the relatively unexplored region of low |tππ| and small ηop mass. We found that the π+ηop cross section is about twice the π-ηop cross section in this region. The ηop mass spectrum for the π+ data shows an enhancement at about 1600 MeV while the π- data show no evidence of a peak in the ηop mass spectrum.

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):
  • Peck, Charles W.
Thesis Committee:
  • Unknown, Unknown
Defense Date:20 December 1979
Funding AgencyGrant Number
Department of EnergyUNSPECIFIED
Record Number:CaltechTHESIS:05192017-102645117
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:10186
Deposited By: Benjamin Perez
Deposited On:19 May 2017 20:58
Last Modified:09 Nov 2022 19:20

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