The 2004 Nobel Prize in Physics Sourendu Gupta (TIFR) St. Xavier’s College, 6/1/2005

Nobel 2004, Sourendu Gupta, Xavier's College, The people David J. Gross Kavli Institute of Theoretical Physics University of California at Santa Barbara USA (b. 1941)

Nobel 2004, Sourendu Gupta, Xavier's College, The people H. David Politzer California Institute of Technology USA (b. 1949)

Nobel 2004, Sourendu Gupta, Xavier's College, The people Frank Wilczek Massachusetts Institute of Technology USA (b. 1951)

Nobel 2004, Sourendu Gupta, Xavier's College, The prize “for the discovery of asymptotic freedom in strong interactions” $1,300,000

Nobel 2004, Sourendu Gupta, Xavier's College, The work Gross and Wilczek, “Ultraviolet behaviour of non- Abelian gauge theories”, Physical Review Letters, vol 30, p , 1973 Politzer: Reliable perturbative results for Strong Interactions?”, Physical Review Letters, vol 30, p , 1973

Nobel 2004, Sourendu Gupta, Xavier's College, Nobel Prizes for the Strong Interactions 2004 Gross, Politzer, Wilczek 1990 Friedman, Kendall, Taylor (DIS) 1982 Kenneth G. Wilson (RG/LGT) 1976 Richter, Ting (J/  ) 1969 Murray Gell-Mann (quark model) 1968 Luis Alvarez (hadrons)

Nobel 2004, Sourendu Gupta, Xavier's College, The two arms of physics Variables: what are the things that make up what we study …analysis Dynamics: how do the variables interact and move ….synthesis

Nobel 2004, Sourendu Gupta, Xavier's College, Elementary Particles: variables 1895: e 1935: e,p,n, , “Who ordered that ?” - Rabi 1950: e,p,n, ,, , , , , ,  … “Had I foreseen that, I would have gone into botany” - Fermi

Nobel 2004, Sourendu Gupta, Xavier's College, QED Variables are e, , ,  Dynamics is Maxwell’s dynamics with quantization: Dirac, Heisenberg, Bethe (1930s) Theory solved in the 40’s (Feynman, Schwinger, Tomonaga) Very successful in describing experiments

Nobel 2004, Sourendu Gupta, Xavier's College, Quantum Hadron Dynamics? Theory of meson baryon interactions was in a mess…. Yukawa theory (1932) 1960s: S-matrix, dual resonance, Regge, string theory…. Variables were wrong, the dynamics was premature

Nobel 2004, Sourendu Gupta, Xavier's College, The Eightfold Way (variables) The “periodic table” of hadrons Building block of hadrons are quarks Mesons contain a quark and an anti- quark, baryons have 3 quarks Masses of hadrons are predictions Gell-Mann, Zweig, Nishijima (1953)

Nobel 2004, Sourendu Gupta, Xavier's College, The Eightfold Way (variables)

Nobel 2004, Sourendu Gupta, Xavier's College, The Eightfold Way (variables)

Nobel 2004, Sourendu Gupta, Xavier's College, The Eightfold Way (variables)

Nobel 2004, Sourendu Gupta, Xavier's College, The Eightfold Way (variables)

Nobel 2004, Sourendu Gupta, Xavier's College, The era of massive confusion Quark search experiments failed. Idea of confinement: quarks live only inside hadrons Colour: Nambu, Fritzsch, Gell-Mann

Nobel 2004, Sourendu Gupta, Xavier's College, The crucial experiment Deep inelastic scattering- the ‘Rutherford experiment’ of particle physics First view of quarks Friedman, Kendall, Taylor (1969) Bjorken, Feynman

Nobel 2004, Sourendu Gupta, Xavier's College, Particles in the Standard Model (1990s)

Nobel 2004, Sourendu Gupta, Xavier's College, Quantum Chromo-Dynamics: the dynamics of quarks and gluons

Nobel 2004, Sourendu Gupta, Xavier's College, Screening in a plasma

Nobel 2004, Sourendu Gupta, Xavier's College, Effective charge A modification to Coulomb’s law is the same as a distance dependent charge: renormalization

Nobel 2004, Sourendu Gupta, Xavier's College, The bubbling vacuum Quantum fluctuations:  t < h/2  Particles can be produced from vacuum for a short time In a quantum field theory the vacuum bubbles over with particles Since it has mobile charges, the vacuum screens

Nobel 2004, Sourendu Gupta, Xavier's College, Charge renormalization: screening in QED

Nobel 2004, Sourendu Gupta, Xavier's College, Anti-screening in QCD Asymptotic freedom is anti-screening: the opposite of electrodynamics

Nobel 2004, Sourendu Gupta, Xavier's College, QCD is born (SLAC to LEP) Asymptotic freedom allowed computation of deep-inelastic cross sections, predicted lepton pair production, jets, etc …many physicists (1970s to 1990s)

Nobel 2004, Sourendu Gupta, Xavier's College, Open problems for you Does anti-screening in vacuum become screening in matter? Are there new phases of matter in xxtreme conditions, like a QCD plasma? Relativistic heavy-ion collisions and LGT… At long distances charge grows; does confinement follow? Are there glueballs? New 5q or 6q states? Why is a proton so heavy? Lattice gauge theory…

Nobel 2004, Sourendu Gupta, Xavier's College, Where it all connects High temperature matter: early in the history of the universe High density matter: in neutron stars and other supernova remnants

Nobel 2004, Sourendu Gupta, Xavier's College, The RHIC at Brookhaven

Nobel 2004, Sourendu Gupta, Xavier's College, The CRAY in TIFR

Nobel 2004, Sourendu Gupta, Xavier's College, Thank You

Nobel 2004, Sourendu Gupta, Xavier's College, How good is QCD?

Nobel 2004, Sourendu Gupta, Xavier's College, How good is QCD?