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Hello All,
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<div>This coming Monday, June 27th at <span style="background-color: rgb(255, 255, 0);">
9AM (EDT)</span>, Alec Hannaford-Gunn will give a (virtual) theory seminar on</div>
<div><a href="https://jlab-org.zoomgov.com/j/1611179843?pwd=M09CNTFpbFVZSW1IQlhIMGp3RUVHUT09" id="LPNoLPOWALinkPreview">https://jlab-org.zoomgov.com/j/1611179843?pwd=M09CNTFpbFVZSW1IQlhIMGp3RUVHUT09</a>
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<div>Please see below for the title and abstract of Alec's talk.</div>
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<div><u><b>Theory Seminar</b></u></div>
<div>Monday, June 27th at 9:00AM</div>
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<div><u><b>Alec Hannaford-Gunn</b></u> (University of Adelaide)</div>
<div>will discuss "A lattice QCD calculation of the off-forward Compton amplitude and generalised parton distributions"</div>
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<div><u><b>Abstract</b></u>:</div>
<div>Generalised parton distributions (GPDs) are observables that provide a unique window into hadron structure, including the spatial distribution of hadron constituents and their spin decomposition. Despite their importance, GPDs remain elusive: they are
difficult to determine experimentally, and lattice QCD calculations have provided only limited constraints on their behaviour.</div>
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<div>I will give an overview a novel method to determine GPD properties in lattice QCD currently being implemented by the CSSM/QCDSF collaboration. We have extended Feynman-Hellmann methods—previously used to calculate the forward Compton amplitude—to determine
the off-forward Compton amplitude for soft momentum transfer in the range $-t\in[0.3, 2.2]\;\text{GeV}^2$. As with the physical scattering amplitude, our lattice Compton amplitude is dominated by GPD contributions at high energies. Therefore, I will also present
our efforts to constrain GPD properties from this calculation, especially our determination of the GPD moments $A_{n,0}(t)$ and $B_{n,0}(t)$ for $n=2,4$.
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<div>Have a pleasant weekend!</div>
Caroline, Colin & Patrick<br>
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