tag:blogger.com,1999:blog-10614348.post7944663526492140287..comments2024-01-22T11:26:37.599-08:00Comments on TGD diary: D0 reports a new 3 sigma bump with mass around 325 GeVMatti Pitkänenhttp://www.blogger.com/profile/13512912323574611883noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-10614348.post-48463576793167857522011-04-28T07:01:31.187-07:002011-04-28T07:01:31.187-07:00Still a general comment about experimental mass de...Still a general comment about experimental mass determination. Masses of sufficiently stable particles like electron, muon, proton, neutron, ... can be determined from their behavior in electromagnetic fields.<br /><br />For short-lived particles the mass determination involves much more theory. Typically one identifies the decay products of a resonance and uses conservation laws for momentum and energy to deduce the mass of the resonance. Special relativistic formulas are in central role so that anyone claiming that Einstein was deadly wrong has to revise the entire particle physics from top to bottom-quite a job;-). The peak of the mass value distribution for the bump defines what is called the mass of the resonance. <br /><br />In the case of neutrinos one must use energy and momentum conservation to deduce the four-momentum of neutrino as missing energy and momentum. Neutrino masses are poorly known and TGD suggests that they appear in several p-adic mass scales. This would explain the claimed CPT breaking as apparent.<br /><br /><br />In the case of light quarks the situation is even more theory laden since they cannot be observed directly. Top quark as the heaviest quark is exceptionally simple. Large number of experimental data is used to deduce the optimal estimate for the light quark masses and lattice QCD is also involved. For light quarks the situation is made complex also by the fact that there are two notions of mass: current quark mass which is of order 10 MeV for u and d and constituent quark mass which is by order of magnitude higher. <br /><br />TGD suggests that constituent quarks correspond to valence quarks having higher mass scale than current quarks identifiable as sea quarks. Higher mass scale would be due to a shorter p-adic length. Sea quarks could be perhaps assigned with the color magnetic body of hadron having much larger size than hadron itself. It could be also that part of the time valence quarks are in various mass states corresponding to different octaves of the basic mass: just like the note from music instruments involves superposition of octaves (besides harmonics).<br /><br /><br />The simple analysis of bubble chamber pictures has transformed to an extremely complex data processing. Signal to noise ratio is extremely small and the amount of data processed incredibly large. The need to process effectively this data led to the discovery of web. <br /><br />Among other things, one needs a Monte Carlo simulation of standard model defining the hay stack. The signatures of new physics are needles but unfortunately it is difficult to distinguish them from hays. Standard model predicts the probability distribution for various degree sof needle-ness for hays. if the probability of the hey to look like needle is very small and one still sees the needle, one can conclude that a real needle was there. If the needle was there at 5 sigma level, Nobel committee can conclude that the experimenter has discovered a needle. If several groups have lost and found their needles, a bloody fight for priorities begins and needles find better use than to be lost in haystacks.Matti Pitkänenhttps://www.blogger.com/profile/13512912323574611883noreply@blogger.comtag:blogger.com,1999:blog-10614348.post-6108702093673783042011-04-28T06:10:24.988-07:002011-04-28T06:10:24.988-07:00The order of magnitude for electromagnetic mass di...The order of magnitude for electromagnetic mass differences can be understood and are about 4 MeV for pion. Same order of magnitude for kaon but opposite sign. I have the feeling that the precise understanding was not very good when I last time was interested about mass differences. <br /><br />Masses can be determined quite precisely experimentally (five digit accuracy for kaon) and the history of how mass measurements and related data processing have evolved would be fascinating to read. <br /><br />I remember the student days when students were analyzing manually the spiral tracks of charged particles in magnetic field appearing in bubble chamber pictures. Nowadays everything is computerized. <br /><br />I do not have overall view about the experimental methods in my spine to give a lecture about the topic without preparation;-).<br /><br /><br />The estimation of mass differences theoretically requires wave functions of quark and antiquark in meson. One can understand qualitatively why neutral pion is lighter than charged one due to Coulomb attraction between quark and antiquark. Also for kaon one can understand qualitatively why neutral kaon is heavier. <br /><br />Quantum mechanics is essential for gaining the understanding: in neutral pion one has quantum superposition of uubar pari and ddbar pair making no sense classically.Matti Pitkänenhttps://www.blogger.com/profile/13512912323574611883noreply@blogger.comtag:blogger.com,1999:blog-10614348.post-52930074432971983522011-04-28T01:03:58.265-07:002011-04-28T01:03:58.265-07:00The fact that technicolor figure again tells very ...The fact that technicolor figure again tells very well how desperate the situation is?<br /><br />Can you tell something about the mass differences between a charged and a neutral pion or kaon. How is it calculated or measured? I guess the charged one must be heavier?Ullahttps://www.blogger.com/profile/16634036177244152897noreply@blogger.com