[SEMINARI]: Dr. Bennhold: Nucleon Resonance Excitation with Photons

[Arcadi Santamaria]

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                              S E M I N A R I

             [Image]   Departament de Física Teòrica    [Image]
                          Universitat de València
                       Institut de Física Corpuscular
                       Universitat de València - CSIC

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                    Nucleon Resonance Excitation with Photons

                             Cornelius Bennhold

                       (George Washington University)

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                              Seminari del IFIC
                 Tuesday 12 of December of 2000 at 12:30 PM
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                                    Resum

Just like atomic and nuclear systems, the nucleon has an excitation spectrum
 which is a consequence of its nature as a composite system. This resonance
 spectrum is a reflection of the underlying strong interaction, namely QCD.
   In contrast to nuclear and atomic systems these nucleon resonances have
 large widths and can be difficult to separate experimentally. On the other
  hand, QCD is nonperturbative in this energy region making a prediction of
 the spectrum directly from QCD very difficult. Since nucleon resonances can
  be excited with photons and mesons, methods are presented to investigate
 such excited states through the photoproduction of pions, etas and kaons in
    a coupled-channels framework. The role of polarization observables is
 pointed out in the search for the so-called "missing resonances".Just like
 atomic and nuclear systems, the nucleon has an excitation spectrum which is
 a consequence of its nature as a composite system. This resonance spectrum
    is a reflection of the underlying strong interaction, namely QCD. In
 contrast to nuclear and atomic systems these nucleon resonances have large
 widths and can be difficult to separate experimentally. On the other hand,
   QCD is nonperturbative in this energy region making a prediction of the
 spectrum directly from QCD very difficult. Since nucleon resonances can be
 excited with photons and mesons, methods are presented to investigate such
  excited states through the photoproduction of pions, etas and kaons in a
 coupled-channels framework. The role of polarization observables is pointed
         out in the search for the so-called "missing resonances".

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