<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hello Annalisa, Andrea, and Martina,<div class=""><br class=""></div><div class="">I have been looking through your interesting slides from last Friday’s meeting,especially the pages pertaining to Delta++ pi- and Delta0 pi+. It is very nice to finally have some data to look at for these reactions to compare the E observable!</div><div class=""><br class=""></div><div class="">I think the Delta++ is always the one that gets excited most readily, as seen in slides 15 and 16. The Delta++ stands out most strongly. As we go up in W, it appears that non-resonant pi+ p must become more important… but we know that has to happen. The upper end of the spectra are cut of by the available energy in the reaction , I think. To extract the Delta’s I would do fits like you did, but maybe try a Lorentzian line shape instead of Gaussian. </div><div class=""><br class=""></div><div class="">I have to admit that the Delta0 line shapes on page 16 look disturbing: they are just not “clean”. By the way, did you make these plots at each of the production angles shown on pages 18 and 19? They may look different depending on the production angle…. for better or for worse. </div><div class=""><br class=""></div><div class="">Page 21 shows my “prediction” based on the idea that a single quark carries the spin polarization information about a given nucleon. In the case of the proton that would be the down quark. But who is to say ahead of time to what extent that is true? Going beyond the simple quake model we know that the nucleon spin is a complicated mixture of quark spin, orbital angular momentum, and gluonic components. Page 21 was my idea how things would look in an idealized world where the spin is carried entirely by a valence quark. </div><div class=""><br class=""></div><div class="">Your preliminary result on page 22 shows that this simple idea is not correct. This may be a great result! It could be excellent evidence about the degree of spin polarization is carried by the up and the down quarks in the proton (or Delta). I am not aware of any other experiment that has been able to do this “apples to apples” measurement at these energies. It would be especially intriguing if the difference you see between the states are really there, that is, if the Deltas were not identical. We need to dream up ways to make the Delta selection more robust.</div><div class=""><br class=""></div><div class="">Cheers,</div><div class="">Reinhard</div><div class=""><br class=""></div><div class=""><br class=""><div apple-content-edited="true" class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">_____________________________________________________________<br class="">Reinhard Schumacher Department of Physics, 5000 Forbes Ave.<br class="">Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A.<br class="">phone: 412-268-5177 web: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__www-2Dmeg.phys.cmu.edu_-7Eschumach&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=S2ZLWreG80lNvNTOLF-ZWA&m=mkCQ6g5LCGANk2k4E7lBjuseKTPi4stjpRDxzQmrIWg&s=0dtfeuUtUlFoSiU2ZBKLMIcev5u0H6WogToGuqjWnr4&e=" class="">www-meg.phys.cmu.edu/~schumach</a><br class="">_____________________________________________________________<br class=""></div></div></div></div></div></div></div></div><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">
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