Antiprotons at CERN 1959 first extracted beam L

Antiprotons at CERN • 1959 – first extracted beam L. Montanet: “At the 1956 Symposium, Blokhintsev was suggesting that the nucleon can be described by a “pion cloud” and a “core” with a radius given by the inverse mass of the K-meson” Proc. LEAP-2000 conf.

The OZI rule • Processes with disconnected quark lines are suppressed • It is not possible to produce ss meson in the non-strange particle interactions. • The - meson production is only due to light quarks admixture Weighted average of all experimental data • N R( / )=(3. 30 0. 34)10 -3 • NN R( / )=(12. 78 0. 34)10 -3 • NN R( / )=(14. 55 1. 92)10 -3 R( / )=tg 2( - I)=4. 2 10 -3

• Crystal Barrel, 1995, LQ hydrogen target • p + p → + • R( ) = (294 97) • R( )OZI = 4. 2 10 -3 • L=0, S=0 1 S 0 Почему эта реакция запрещена из 3 S 1 spin singlet

• OBELIX, 1995, LQ, NTP, 5 mb • p + p → + • R( ) = (114 10) 10 -3 • R( )OZI = 4. 2 10 -3 • L=0, S=1 3 S 1 • spin triplet Почему?

-2 • Different situation for annihilation from S- and P -waves • R( ) = (120 12) 10 -3 3 S 1 • R( ) = < 7. 2 10 -3 1 P 1 • spin triplet – enhanced • spin singlet – suppressed

f 2’(1525) / f 2(1270) • Tensor mesons: L=1, S=1, J=2 f 2(1270) normal q q f 2’ (1525) s s • • R(f 2’ f 2) = (47 14) 10 -3 3 S 1 R(f 2’ f 2) = (149 20) 10 -3 1 P 1 spin triplet – suppressed spin singlet – enhanced

• OBELIX, 1995, NTP, 5 mb • p + p → + + + For all events: • R( ) = (5 -6) 10 -3 • R( )OZI = 4. 2 10 -3 For events with M =300 -500 Me. V • R( ) = (16 -30) 10 -3

n n • OBELIX, Crystal Barrel • p + d → + n B. Pontecorvo, 1956 One-meson annihilation • R( ) = (156 29) 10 -3 • R( )OZI = 4. 2 10 -3

p + p→ + • If it was normal quark reaction s p p s s s • ( )exp ~ 4 b • why it so large? • ( ( ) not measured)

• pp • JETSET (PS 202) Non-magnetic spectrometer, 11 400 events • is definitely different from KK or 4 K • Main contributions: – JP = 2+, L( )=2, S( )=2 – JP = 2+, L( )=0, S( )=2 – JP = 2+, L( )=2, S( )=0 (resonance-like, m=2231 2 Me. V, =70 10 Me. V) A. Palano, Workshop on Hadron Spectroscopy, Frascati, 1999, p. 363

– OZI violation in pp pp ( ) at threshold, 14 times DISTO – and angular distributions are different COSY TOF – Negative Dnn DISTO – OZI violation in pd 3 He ( ), 20 times SPES 4 Saturne

At LEAR experiments Strong violation of the OZI rule was found in • pp , • pp (3 S 1) • pd n Is it depends on – – spin orbital angular momentum transfer isospin?