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<font color="#000099"><b><font color="#3333ff">Physics Seminar<br>
Friday, March 12, 2010<br>
11:00AM<br>
CEBAF Center AUD.<br>
Cookies & Coffee at 10:45AM</font></b><br>
</font><br>
<br>
<b><font color="#990000">"Hadron Spectroscopy from QCD"
<br>
<br>
Jo Dudek
<br>
Jefferson Lab & ODU</font></b>
<br>
<br>
Jefferson Lab Theory Center members, as part of the "Hadron Spectrum
Collaboration", have developed and applied advanced field-theoretical
techniques to enable the extraction of the excited state hadron
spectrum from Lattice QCD computations. I will present some highlights
of this large-scale program including a demonstration in a
model-independent framework that mesons with exotic quantum numbers
exist within QCD and are likely in a mass region accessible to the 12
GeV CEBAF. I will also discuss the extraction of an excited baryon
spectrum and the possibility of computing transition form-factors and
photocouplings of excited and exotic hadrons.
<br>
<br>
As well as the reliable extraction of state energies, we are beginning
to build a quark-gluon phenomenology from interpretation of the QCD
matrix elements measured in lattice calculations. Amongst other things,
this demonstrates that exotic quantum numbered states are indeed hybrid
mesons featuring an excited gluonic field and not, for example,
multiquark states. These methods can be used to shed light on the
internal structure of the entire spectrum of meson and baryon
excitations and to probe the limitations of simple models currently in
use to describe these states.
<br>
<br>
I will conclude by describing directions currently being explored to
explicitly observe resonant behaviour in QCD, allowing for extraction
of the hadronic decay widths of excited mesons and baryons.
<br>
<br>
<br>
Upcoming Physics Seminars
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<br>
March 22: Jaiwei Mei (Indiana University)
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<br>
March 24, 26, 29: Series by Leonard Gamberg (Penn State)
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<br>
April 16: Simona Malace (SCU)<br>
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