Prof. Marco Traini

A.A. 1998/99

PROGRAMME
 

The second semester of the course is devoted to the decription of the
subnuclear degrees of freedom and mesons and nucleons will be discussed as
aggregates of quarks.

Lectures will be also given by prof. Vicente Vento (Valencia University, Spain)
within the staff teaching mobility agreement of the SOCRATES project.

Nucleons and pions:

properties of the proton and neutron, charge,
spin, isospin. Conservation laws and symmetry properties. Isospin and SU(2).
The pion and triplets. Experimental tests of isospin invariance: the
pion-nucleon scattering. The hypercharge and the baryons, barionic resonances,
the Gell-Mann - Nishijima relation.

SU(3) symmetry and quarks:
SU(3) representations,
quarks and antiquarks, meson octects, U-spin, The Gell-Mann - Okubo
mass formula.

Quarks with spin:
SU(6), The Young tableaux, the wave function
of the neutron and the proton and their magnetic moments.
The color.

The quark model for the nucleon:
The harmonic oscillator model, the mass of the Delta resonance and the
hyperfine interaction, charge density and electric form factors. The Isgur -
Karl model and the two harmonic oscillator potential.

Interquark potential:
The spectrum of heavy mesons, linear confining potential and Coulomb-like
interaction (nonrelativistic reduction of the one-gluon-exchange interaction).
Numeric solution of the Schrödinger equation and the theoretical spectrum.

Potential models for baryons:
The hyperspherical formalism, the hyperspherical harmonics. Hypercentral
potentials, charge distribution and form factors for simple models. Numerical
solutions of the hypercentral equation and the nucleon spectrum. The role of
the Roper resonance and the three-body forces.
 
 

Reference texts:
 
 

 F.E. CLOSE, An introduction to Quarks and Partons,
Academic Press, London 1979.

 H. FRAUENFELDER e E.M. HENLEY, Subatomic Physics, seconda edizione,
Prentice Hall 1991.

 P. GONZALEZ, The two and three body problems in non-relativistic quantum
mechanics: some techniques, notes of the course given at the Trento
University during the academic year 1997/98.

 M. TRAINI, notes
 

Exam

oral exam on the contents of the lectures.