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Dear all,
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<div class="">yes the next meeting is tomorrow Friday March 10 at 16:00 Europe time (10am US time). </div>
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<div class="">- Vincent</div>
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<div class="">Vincent Mathieu</div>
<div class="">Indiana University Research Fellow</div>
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<div class="">On Mar 9, 2017, at 9:33 AM, Mikhail Mikhasenko <<a href="mailto:mikhail.mikhasenko@gmail.com" class="">mikhail.mikhasenko@gmail.com</a>> wrote:</div>
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<div dir="ltr" class="">Dear all,
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<div class="">the next Gribov lecture is scheduled for tomorrow, Friday 16:00.</div>
<div class="">Please note unusual time!</div>
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<div class="">To prepare for the discussion on analytic structure I suggest to have a look at the homework problem</div>
<div class=""><span id="cid:ii_15ab3709da17b6a6"><Screenshot from 2017-03-09 14-19-09.png></span><br class="">
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<div class="">Please find attached Mathematica notebook and note where Karplus curve is plotted for some arbitrary masses of particles in the box.</div>
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<div class="">See you tomorrow and best wishes,</div>
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<div class=""> Misha Mikhasenko</div>
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<div class="gmail_quote">On 2 March 2017 at 17:43, Mathieu, Vincent <span dir="ltr" class="">
<<a href="mailto:mathieuv@indiana.edu" target="_blank" class="">mathieuv@indiana.edu</a>></span> wrote:<br class="">
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<div style="word-wrap:break-word" class="">Misha,
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<div class="">thank for this very clear lecture. </div>
<div class="">You derive the Karplus curve representing the singularity of the box diagram, in the equal mass case. </div>
<div class="">Here is a paper about the box diagram in pion photoproduction: <a href="http://inspirehep.net/record/120443?ln=en" target="_blank" class="">http://<wbr class="">inspirehep.net/record/120443?<wbr class="">ln=en</a></div>
<div class="">The author claims that the singularities are in the physical region, t < 1.1 GeV^2 for s > 1.6^2 GeV^2</div>
<div class="">(for one particular box, other boxes are outside the physical region as in your example)</div>
<div class="">See Fig 2 and the discussion above. </div>
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<div class="">That means that fixed t dispersion relation (as I used them for FESR) can be ill defined for t < 1.1 GeV^2</div>
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<div class="">There is no explicit calculation. I suppose the curve on Fig comes from a similar demonstration as you did. </div>
<div class="">If somebody does this exercise, I’d happy to have a confirmation of the result. </div>
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<div class="">*** The next Gribov Lecture is Friday March 10 at 9am (US time - 3pm in Europe) *** </div>
<div class="">Misha could you confirm this schedule ?</div>
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<div class="">Cheers,</div>
<div class="">Vincent</div>
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<div class="">------------------------------<wbr class="">----------------------</div>
<div class="">Vincent Mathieu</div>
<div class="">Indiana University Research Fellow</div>
<div class="">INFN-Genova Associate</div>
<div class="">UMons Associate</div>
<div class=""><a href="mailto:mathieuv@indiana.edu" target="_blank" class="">mathieuv@indiana.edu</a></div>
<div class="">Office Phone: <a href="tel:(812)%20855-2900" value="+18128552900" target="_blank" class="">
+1 812 855 2900</a></div>
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<div class="">Joint Physics Analysis Center:</div>
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<span id="cid:241DB0BD-919A-4C1D-A276-AFFC2A75BD8D@indiana.edu"><karplus.nb></span><span id="cid:104F5906-B750-46AA-9F03-4DC81657B283@indiana.edu"><Karplus_example.pdf></span>_______________________________________________<br class="">
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