BIRTH OF MESON Early history 1930’s

1. INPC07, Yukawa Session, June 3, 2007Interplay between Yukawa and Tomonagain the Birth of Meson Toshimitsu Yamazaki, Nishina Memorial Foundation

2. BIRTH OF MESONEarly history 1930’s Interaction Interplay Y. Nishina (RIKEN) Father of Modern Science One of the discoverers of the muon in 1937 S. Tomonaga 1965 N. L. H. Yukawa 1949 N. L.

3. 1935 For instance, J (r) = A exp(- lr) / r Yukawa potential force range parameter l= mUc / h mass of mediating particle U

4. 1932 Discovery of the neutron (Chadwick)1932 Heisenberg theory of nuclear structure 1933 spring meeting of JPMS (Sendai) both: 26 years old • Yukawa (Kyoto --> Osaka): On the problem of nuclear electrons Nishina suggested a boson Bose electron? • Tomonaga (RIKEN): On the proton-neutron interaction using J (r) = A exp(- lr) / r nothing but Yukawa’s interaction !!!

5. Interplay between Yukawa and TomonagaLetter from Tomonaga to Yukawa ~1933Yukawa Archive at Yukawa Institute for Fundamental Physics, Kyoto

6. In fact, on the “back of the envelope” Yukawawrote down the electron Compton wavelength ~ 3 x 1010 cm-1 !!  e = 260!!, which would mean mU / me = 260 Electron Compton wavelength ?

7. Tomonaga used the form J(r) = Aexp(-r)/rto account for the deuteron binding energy and p (n,) d reaction; yielding 6.5 x 1012 /cm This letter must have affected Yukawa deeply, but, in the spring of 1933, neither of Yukawa and Tomonaga recognized the importance of the above formula and the implication of . Tomonaga published in 1936 Bethe-Peierls 1935 Tomonaga and Araki 1940 positive and negative meson capture to disentangle the problem of +/- pion/muon Fermi-Teller-Weisskopf 1947

8. Yukawa’s 1st paper in 1935 Yukawa’s acknowledgement to Tomonaga

9. a la K. Nishijima Yukawa’s strugglingin 1933how can a migrating real particle exist in nuclei?Bose electron ?force range ? p + e- = n ? Finally, in 1935, Yukawa arrived at virtual mediatingparticle

10. The Yukawa theory A virtual particle mediates strong interaction • mU/me ~ 200 • The mesons discovered • Fundamental concept in physics Heitler-London- Heisenberg scheme: completely abandoned ?

11. Structure of K-ppTheoretical predictionY. Akaishi, T.Y.Proc. Jpn. Acad. Ser. B 83 (2007) 144

12. Revival of the Heitler-London-Heisenberg scheme ! Cold Dense Nuclei - Kaon Condensation

13. Thank you very much