1. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics1 Seminar Subatomic Physics Chapter 3: New developments in hadronic particle production Nucleon resonances Baryon models Partial-wave analysis Coupled channels Bethe-Salpeter equation K-matrix approximation CLAS at Jlab TAPS+CrystalBarrel at ELSA

2. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics2 pion nucleon scattering Isospin coupling, invariant mass (4-mom. sum) and phase-shift analysis yield energy (mass), I, L, J resonance assignment: L 2I,2J (mass) and width (lifetime)  (1232) P 33  (1950) N(1680) N(1520)

3. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics3 nucleon g.s. and excitations partly explained in the quark model chromomagnetic (hyperfine) interaction radially excited spatial states Roper res. (1710) (1440)

4. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics4 nucleon resonances in quark potential model: qualitative understanding mass (MeV) confining potential gluonic excitations well poorly known

5. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics5 pion nucleon scattering  - p  X reaction channels: influence of channel opening unitary reaction model needs to include all important channels real part of S 11 partial wave ampl. influence of neglecting channels w/o  N final state  N width  2  N cross section (mb) 10 20

6. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics6 partial-wave analysis quantum scattering in 3 dimensions (halfplane  =0) scattering amplitude

7. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics7 baryon resonances elastic: unitary circle inelastic cross section reaches unitary limit

8. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics8 actual D 13 resonance analysis requires high quality cross sections, polarization observables coupled-channel K-matrix approach w/o D 13 (1900) state

9. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics9 calculations at tree-level neglect: hadronic final-state interaction  violation of unitarity requires: coupled-channels method including rescattering e.g.  N  K  using: hadronic form-factors violates: gauge invariance repaired by contact term K Y K K K Y Y Y N  N N*  Y K example: K photoproduction

10. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics10 ladder approximation solution to scattering problem: iterate interaction potential V Bethe-Salpeter equation: 4-dim. integral equation,  (all allowed intermediate 2-particle states) Bethe-Salpeter propagator K-matrix approximation: modify Re(G bs ) without violating unitarity

11. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics11 Summary: motivation: low-energy QCD in confinement regime not accessible by perturbation theory QCD lattice theory: numerical solutions effective quark models program to study hadronic and electromagnetic excitation of nucleon analysed by dynamical model description satisfying unitarity, analyticity, Lorentz- and gauge-invariance  masses, decay widths of resonance states

12. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics12 Literature: 1. Scattering Theory: Sakurai, Modern Quantum Mechanics, Addison-Wesley 1994 p.379-399 2. Compton scattering on the proton and light nuclei in the Delta resonance region (K Matrix approach) O. Scholten, Acta Physica Polonica 33 (2002) 847-871 3. Vector meson production with photons and nucleon resonance analysis in a coupled channel approach G. Penner, U. Mosel, nucl-th/0207069nucl-th/0207069 4. Pseudoscalar and vector meson production in NN collisions K. Nakayama, nucl-th/0108032nucl-th/0108032

13. HL-ch.3 Sept. 2002Student Seminar Subatomic Physics13 Seminar contributions semester week calendar week datetopicname 136 4 sept. 1.1 oscillations 33818 sept.1.2 solar neutrinos 43925 sept. 1.3 mass limits 540 2 oct. 1.4 -less double  decay 641 9 oct.2.1 quantum Monte Carlo 74216 oct.2.2 ab initio shell model 84323 oct. 2.3 supernova detection 94430 oct.3.1 scattering theory 1045 6 nov.study week Münster 114613 nov.3.2 Compt. scatt. & K-matrix 124720 nov.3.3 coupl. ch. reson. analysis 134827 nov.3.4 meson prod. in NN coll.