1. Photons in a permutation anti-symmetric state? and What would a quantum-statistic violation mean? Dmitry Budker http://socrates.berkeley.edu/~budker Inauguration Meeting Iceland, July 2007 Support: N$F

2. Identical particles: the ultimate equality Permutation symmetry postulate Spin-Statistics Theorem (SST)  Individualism: the ultimate diversity

3. Prof. Richard P. Feynman (1918-1988) Feynman’s Lectures on Physics, V. 3:

4. Okun’ on Pauli

5. How? Landau-Yang Theorem! Landau, L. D., Dokl. Akad. Nauk., USSR 60, 207-209 (1948) Doesn’t go because no symmetric state for two photons with J=1

6. Landau-Yang theorem and the degenerate two-photon transition selection rule L-Y: V(J=1)   L-Y: V(J=1)   Inverse L-Y: Nothing(J=0) +   V(J=1) Inverse L-Y: Nothing(J=0) +   V(J=1)  Destructive interference of two quantum paths S. N. Bose

7. DeMille 1 1999

8. Interaction region

9. Lasers

10. Results

12. Numbers

13. Damon English

14. Disturbing Questions No consistent relativistic theory accommodating a statistics violation How to compare with other experiments? (Z→γγ, …) Constrains from lasers, BBR, static limit ?  Need a generalized E&M theory