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Dear Colleagues,
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<div class="">I was asked to talk on “Probing the hadron spectrum with photon-proton collisions” at the INPC conference in September. I propose to submit the abstract below. Please may I have your comments and suggestions.</div>
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<div class="">Best,</div>
<div class="">Mark</div>
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<div class=""><b class="">Probing the hadron spectrum with photon-proton collisions<br class="">
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New, high-luminosity experiments have driven a resurgence of interest in hadron spectroscopy. The discovery of dozens of new heavy-quark hadrons that are not described by the naive quark model suggest additional degrees of freedom. Photoproduction is an attractive
process to study the hadron spectrum with production mechanisms and kinematics that are complimentary to other experiments. s-channel production of pentaquark candidates is complementary to production in B decay, without the complication of 3 body dynamics. The
GlueX experiment uses a linearly polarized photon beam of up to 12 GeV in energy on a proton target with hermetic detector system, and has accumulated more than 800 pb^-1 of luminosity. The primary goal is the systematic study of the spectrum of light quark
hybrid mesons, where the excited gluonic field contributes directly to their properties. The energy also allows the study of bound charmonium states near threshold and the search for Pc states with a possible 5-quark structure. The most recent results of
this experimental and related theoretical effort will be reviewed. The prospect for studies at a future Electron Ion Collider or energy upgraded CEBAF will also be mentioned.<br class="">
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