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Electron positron annihilation related to string theory

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no,location=no, scrollbars=yes,resizable=yes,status=no,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>"Urs Schreiber" &lt;Urs.Schreiber@uni-essen.de&gt; wrote in message\nnews:Pine.LNX.4.31.0405280610510.28118-100000@kaluza.harvard.edu...\n| On Fri, 28 May 2004, Robert C. Helling wrote:\n|\n| &gt; On Fri, 28 May 2004 02:01:34 -0400, FrediFizzx &lt;fredifizzx@hotmail.com&gt;\nwrote:\n| &gt; &gt; I was wondering how string theory deals with e+e- annihilation or the\n| &gt; &gt; annihilation of any pair. If the electron and positron are\nrepresented by\n| &gt; &gt; strings, do the strings just disappear forever when they annihilate?\n| &gt;\n| &gt; No. As in QED, they will send out at least to photons to satisfy\n| &gt; energy momentum conservation. Thus this process is at leading order a\n| &gt; pair of pants diagram (or better its open string analogue) with the\n| &gt; two incoming strings being in the electron mode and the two outgoing\n| &gt; string in the gauge boson mode.\n|\n| On the other hand, you certainly can have processes in which the string\n| sort of "disappears", namely for instance in pure loop diagrams, if that\'s\n| what Fredi is concerned about.\n\nWell, actually I was more concerned about what Robert mentioned. Which I\nknew and forgot. This tired old mind just has a hard time keeping track of\nall this stuff. ;-)\n\n| So in this sense I believe that it is fair to say that strings can\n| "appear and disappear".\n\nI sure do have trouble with this "appear and disappear". Seems like we need\nanother space for things (entities?) to appear from and disappear to.\n\nFrediFizzx\n\n[Moderator\'s note: Quoted text trimmed by moderator. -usc]\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">&nbsp;&nbsp;View this Usenet post in original ASCII form </a></div><P></jabberwocky>"Urs Schreiber" <Urs.Schreiber@uni-essen.de> wrote in message
news:Pine.LNX.4.31.0405280610510.281...harvard.edu...
| On Fri, 28 May 2004, Robert C. Helling wrote:
|
| > On Fri, 28 May 2004 02:01:34 $-0400,$ FrediFizzx <fredifizzx@hotmail.com>
wrote:
$| > > I$ was wondering how string theory deals with $e+e-$ annihilation or the
$| > >$ annihilation of any pair. If the electron and positron are
represented by
$| > >$ strings, do the strings just disappear forever when they annihilate?
| >
$| > No$. As in QED, they will send out at least to photons to satisfy
| > energy momentum conservation. Thus this process is at leading order a
| > pair of pants diagram (or better its open string analogue) with the
| > two incoming strings being in the electron mode and the two outgoing
| > string in the gauge boson mode.
|
| On the other hand, you certainly can have processes in which the string
| sort of "disappears", namely for instance in pure loop diagrams, if that's
| what Fredi is concerned about.

Well, actually I was more concerned about what Robert mentioned. Which I
knew and forgot. This tired old mind just has a hard time keeping track of
all this stuff. ;-)

| So in this sense I believe that it is fair to say that strings can
| "appear and disappear".

I sure do have trouble with this "appear and disappear". Seems like we need
another space for things (entities?) to appear from and disappear to.

FrediFizzx

[Moderator's note: Quoted text trimmed by moderator$. -usc]$