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<p>Theory Center Seminar<br>
Wednesday, January 17, 2018<br>
2:00 p.m. (coffee at 1:45 p.m.)<br>
CEBAF Center, Room L102 <br>
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Thomas Mehen<br>
Duke University<br>
<font color="#0f61c8"><br>
</font><b>Quarkonium Production in Jets</b><br>
<font color="#0f61c8"><br>
</font>This talk will describe new tests of quarkonium production
using quarkonia that are produced within jets. <br>
We study the distribution in the fraction z of a jet's longitudinal
momentum carried by the quarkonium. <br>
The zdistribution is sensitive to the underlying NRQCD production
mechanism. Analytic calculations the <br>
zdistributions in SCET that incorporate Next-to-Leading-Log
(NLL) resummation disagree with default PYTHIA<br>
predictions. We describe a modified simulation method which agrees
well with NLL analytic calculations. <br>
This method is then successfully applied to recent LHCb measurements
of J/ψ within jets. We discuss the<br>
implications of this measurement for extractions of NRQCD
long-distance matrix elements. Finally, we discuss<br>
other observables involving quarkonium within jets which may be
useful for discriminating between NRQCD <br>
production mechanisms.<br>
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