tag:blogger.com,1999:blog-22973357.post2831061302772476514..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: The J/Psi and the Charmonium SpectrumSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-22973357.post-39342980050472722962007-12-22T05:25:00.000-05:002007-12-22T05:25:00.000-05:00Hi Neil,to my knowledge, there is nothing like the...Hi Neil,<BR/><BR/><BR/>to my knowledge, there is nothing like the Lamb shift involved in the analysis of charmonia with Cornell-type potentials. The reason is, I think, that these potentials are just ansätze, they are definitely not thought to be fundamental in the sense that the Coulomb potential is the fundamental potential between electrical charges. Hence, thinking about QFT induced stefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-37395290374848507442007-12-22T05:14:00.000-05:002007-12-22T05:14:00.000-05:00Hi Chris,I think one should keep in mind that usin...Hi Chris,<BR/><BR/><BR/>I think one should keep in mind that using a potential interaction is a nonrelativistic concept, and that that the analogy between charmonium and the hydrogen atom via quantum states in the Cornell and Coulomb potentials works because the charm quark has a very big mass - it's a bit less than half the mass of the J/Ψ (about 1.3 GeV, compared to 3.096 GeV for the J/&Psistefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-76384178655294142562007-12-21T17:31:00.000-05:002007-12-21T17:31:00.000-05:00(reply to Neil)> I thought QFT was so complete and...(reply to Neil)<BR/><BR/>> I thought QFT was so complete and<BR/>> effective to nth decimal, so do you<BR/>> mean what people do instead of what<BR/>> the theory in principle can do?<BR/><BR/><BR/>What I meant is what people do.<BR/><BR/>In the case of charmonium, it's largely due to the fact that there are not many easy ways to do non-perturbative calculations in the QFT formalism. Doing Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8146331478966792822007-12-21T16:49:00.000-05:002007-12-21T16:49:00.000-05:00Is there an analogy to the Lamb shift in the Charm...Is there an analogy to the Lamb shift in the Charmonium spectrum, and what does it "tell us" if any? tx<BR/><BR/>Also, I am curious re:<BR/>"I've always been bothered by how quantum field theory doesn't really look at the bound state problem extensively (with the exception of maybe the lattice folks)."<BR/><BR/>I thought QFT was so complete and effective to nth decimal, so do you mean what peopleNeil Bateshttps://www.blogger.com/profile/04564859009749481136noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-64499429616609824182007-12-21T12:05:00.000-05:002007-12-21T12:05:00.000-05:00(reply to Chris Oakley)I've always been bothered b...(reply to Chris Oakley)<BR/><BR/>I've always been bothered by how quantum field theory doesn't really look at the bound state problem extensively (with the exception of maybe the lattice folks).<BR/><BR/>On the other hand, attempting to calculate QED results using conventional quantum mechanics (ie. without any field theory) is really messy, such as in the first edition of Heitler's book.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-28165004340728232512007-12-21T04:26:00.000-05:002007-12-21T04:26:00.000-05:00Since the study of the single-electron atom ultima...Since the study of the single-electron atom ultimately led to quantum mechanics, I am optimistic that the study of charmonium will ultimately lead to a proper theory of strong interactions.<BR/><BR/>The problem with the 2-body microscopic bound state is that it appears not to be an advantage to use more sophisticated treatments: naive solving for eigenstates of a classical potential actually doesAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-62449525728026743852007-12-20T11:58:00.000-05:002007-12-20T11:58:00.000-05:00One can do this not only towards spectroscopy of s...One can do this not only towards spectroscopy of smaller structures, but also larger, like e.g. <A HREF="http://en.wikipedia.org/wiki/Raman_spectroscopy" REL="nofollow">for molecules</A>. It's all about excitations... Best,<BR/><BR/>B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.com