Feynman and the quarkparton

Transcription

1 Feynman and the quarkparton models Finn Ravndal, Dept of Physics, University of Oslo graduate student at Caltech The quark model The parton model - jets QCD and leaving Caltech PhD and the Cornell Meeting Oberwölz, 3/9-2012

2 graduate student 1965: Summer student CERN SU(3) 1966: Engineering degree, NTH, Norway 1967: Hydrogen atom with SU(2) x SU(2) symmetry 1968: Caltech and Pasadena Cisneros Bogoliubov, Bjorken, YM

3 1968: Caltech and Pasadena: Colloquium, Bjorken, partons Veneziano, duality John Bahcall - Kellogg Lab. Feynman, HEP I: spectroscopy, quarks A, B & C Frautschi, Yang s theorem + Regge theory

4 the quark model Clem Heusch: phenomenology Caltech electron synchrotron, photoproduction Copley, Karl and Obryk PRL: P (1720) 11 Lauritsen - Downs Hi Finn, I m Dick Feynman! What s this quark model you are working on? Mark Kislinger

5 covariant quark model Feynman, HEP II: current commutators & dispersion relations Chris Hamer, eikonal Regge model, Serpukhov accelerator Feynman, rising x-sections in parton model Covariant quark model: 1) Covariant 2) Conserved vector currents and PCAC 3) Straight Regge trajectories

6 Baja California

7 Numerical Data and Functional Relationships in Science and Technology (Springer-Verlag, Berlin, 1967), Vol. ~~P. Pritchett and P. Zucker, Phys. Rev. D 1, 175 (1970). PH YSICAI REVIEW D VOLUME 3, NUMBER 11 1 JUNE 1971 Current Matrix Elements from a Relativistic Quark Model* R. P. Feynman, M, Kislinger, and F. Ravndal Lauritsen Laboratory of Physics, California Institute of Technology, Pasadena, California (Received 17 December 1970) A relativistic equation to represent the symmetric quark model of hadrons with harmonic interaction is used to define and calculate matrix elements of vector and axial-vector currents. Elements between states with large mass differences are too big compared to experiment, so a factor whose functional form involves one arbitrary constant is introduced to compensate this. The vector elements are compared with experiments on photoelectiic meson production, X&& decay, and m aery. Pseudoscalar-meson decay widths of hadrons are calculated supposing the amplitude is proportional (with one new scale constant) to the divergence of the axial-vector current matrix elements. Starting only from these two constants, the slope of the Regge trajectories, and the masses of the particles, 75 matrix elements are calculated, of which more than 4 agree with the experimental values within 40%. The problems of extending this calculational scheme to a viable physical theory are discussed. Feynman, Kislinger, Ravndal, CALT : INTRODUCTION The symmetric, nonrelativistic harmonic-oscillator quark model has been shown by a number of people" to offer considerable promise of helping to organize the wealth of data in the resonance region for high-energy phenomena. We intend here to bring some of these results together in a unified method of calculation in order to judge better the validity of this organizing power. i.e. quarks are effectively bosons! ficing theoretical adequacy for simplicity. We shall choose a relativistic theory which is naive and obviously wrong in its simplicity, but which is definite and in which we can calculate as many things as possible not expecting the results to agree exactly with experiment, but to see how closely our "shadow of the truth" equation gives a partial reflection of reality. In our attempt to maintain simplicity, we shall evidently have to violate known principles of a complete relativistic The = 1/2 rule from the symmetric quark model.

8 quarks to partons February 2: 1) San Fernando earthquake 2) Feynman parton seminar 3) Harald Fritzsch in Pasadena May: PhD and now post.doc. August: Electron - Photon Conference, Cornell Cambridge dual parton model Unruly flight back, Kaufman, parton lectures Fritzsch - Gell-Mann lightcone commutators Hey-Mandula paper

9 partons Arturo Cisneros, lecture notes: Photon-Hadron Interactions Quark fragmentation, jets, transverse momentum Quark charges: Brodsky - Farrar discussion Gronau-Zarmi collaboration Fritzsch - Gell-Mann back from CERN: Color and QHD Chicago Meeting

10 QCD Azimuthal dependence 1-particle inclusive Charmed quarks? No Electroweak unification? No new physics from requirement of renormalizability! Talk in Norway - and one extra year at Caltech! Asymptotic freedom MGM and the renormalization group Mandula-Curtright collaboration: Covariant parton model Irvine December Meeting - Salamions

11 end at Caltech 2-dim QED and Kaufman potential Research Fellow at Nordita Discussion with Frautschi - depression London meeting November Revolution Conclusion P, N,Λ u, d, s Arturo Cisneros