Il Nuovo Cimento A (1965-1970)

, Volume 44, Issue 2, pp 504–511 | Cite as

Positive-pion photoproduction at 180° near the second nucleon-pion resonance

  • C. Schaerf


In a previous experiment the cross-section for the photoproduction of pions in hydrogen near the second pion-nucleon resonance has been measured at 135° and 180° in the c.m.s. At 180° the measurements did show a very sharp peak at a gamma-ray energy of 700 MeV. The experiment has now been repeated only at 180°, with improved energy resolution. The new results, in agreement with the old ones, show the same sharp energy dependence at about the same value of the primary energy.


Absolute Calibration Gating Pulse Pion Photoproduction Nuclear Magnetic Resonance Probe Empty Target 
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In un precedente esperimento si è misurata la sezione d’urto per la fotoproduzione di pioni positivi in idrogeno a 135° e 180° nel centro di massa vicino alla seconda risonanza pione-nucleone. A 180° le misure hanno indicato un picco molto pronunciato ad un’energia del gamma di 700 MeV. L’esperimento è stato ora ripetuto solamente a 180° migliorando il potere risolutivo sull’energia del gamma. I nuovi risultati sono in accordo con i precedenti e mostrano la stessa dipendenza dall’energia a circa lo stesso valore dell’energia primaria.


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  1. (1).
    L. Hand andC. Schaerf:Phys. Rev. Lett.,6, 229 (1961).ADSCrossRefGoogle Scholar
  2. (2).
    In the previous experiment the gamma-ray energy resolution was under-estimated. Its real value was not 15 MeV as quoted but 20 MeV.Google Scholar
  3. (3).
    K. L. Brown:Rev. Sci. Instr.,27, 615 (1956).Google Scholar
  4. (4).
    H. Fisher andC. Schaerf:Rev. Sci. Instr.,35, 615 (1964).ADSCrossRefGoogle Scholar
  5. (5).
    Dr.E. A. Allton kindly provided an improved version of the program described byR. A. Alvarez jr.:Thick Radiator Bremsstrahlung, HEPL-228.Google Scholar
  6. (6).
    R. A. Alvarez, K. L. Brown, W. K. H. Panofsky andC. T. Rockhold:Rev. Sci. Instr.,31, 556 (1960).ADSCrossRefGoogle Scholar
  7. (7).
    M. Bazin andC. Schaerf:Absolute Calibration of the Triple Focusing Spectrometer, HEPL-250.Google Scholar
  8. (8).
    D. Drickey andL. N. Hand: private communication.Google Scholar
  9. (9).
    A bibliography on pion photoproduction can be found in:Ph. Salin:Nuovo Cimento,28, 1294 (1963);G. Höhler andW. Schmidt:Ann. of Phys.,28, 50 (1964).CrossRefGoogle Scholar
  10. (10).
    H. De Staebler, E. F. Erickson, A. C. Hearn andC. Schaerf:Phys. Rev.,140, B 336 (1965).ADSCrossRefGoogle Scholar
  11. (11).
    J. J. Sakuray:Phys. Rev. Lett.,7, 355 (1961).ADSCrossRefGoogle Scholar

Copyright information

© Società Italiana di Fisica 1966

Authors and Affiliations

  • C. Schaerf
    • 1
  1. 1.High-Energy Physics LaboratoryStanford UniversityStanford

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