ojaf05 kondrat

Strangeness production in exclusive and inclusive reactions and problem of pentaquark: 

Strangeness production in exclusive and inclusive reactions and problem of pentaquark V.Yu. Grishina INR RAS & ITEP, Moscow, Russia L.A. Kondratyuk ITEP, Moscow, Russia 5th – 9th December, 2005 ITEP, Moscow, Russia

Slide2: 

To investigate the production mechanism of L, S0, L (1520) within the Quark-Gluon Strings Model (QGSM) combined with Regge phenomenology (QGSM was proposed by A.B.Kaidalov in Z.Phys. C 12, 63, 1982) To obtain restrictions on the Q+ production cross section See also V.Yu.Grishina et al., Eur. Phys. J. A 25, 141, 2005

for gp  K+ L & gp  K0 Q+: 

for gp  K+ L & gp  K0 Q+

K* -Reggeon exchange amplitude for thereaction gp  K+ L : 

K* -Reggeon exchange amplitude for the reaction gp  K+ L

gp  K+ L differential cross section: 

gp  K+ L differential cross section K-exchange contribution (dashed line) grKK*=g0=5.8 (Kaidalov et al.) gpK*L=3.5 (found from fit)

gp  K+Y total cross sections: 

gp  K+Y total cross sections gpK*L= gpK*S =3.5 gpK*L(1520) =4.14

gp  K0 Q+ total cross section: 

gp  K0 Q+ total cross section Universality prediction: gpK*Q= gpK*L(1520) =4.14 If s= 200 nb at 2 GeV (SAPHIR 2004) gpK*Q= 0.4 gpK*L(1520) If s= 4 nb (upper limit from CLAS April 2005) gpK*Q= 0.06 gpK*L(1520)

p-p  K0 L: 

p-p  K0 L gpK*L = 4.5

p-p  K0 L & p-p  K– Q+ : 

p-p  K0 L & p-p  K– Q+ gSAPHIRpK*Q= 1.8 gCLASpK*Q= 0.25

pp  p K0Q+ & pp  Q+ X: 

pp  p K0Q+ & pp  Q+ X gQKN=1.4 GQKN=1MeV

pp  S+ Q+ , K & K* exchanges: 

pp  S+ Q+ , K & K* exchanges GQKN=20MeV, K-exchange Liu & Ko 2003 COSY-TOF 2004 gpK*Q from SAPHIR gpK*Q from CLAS If GQKN=1MeV

pp  p K+ L : 

pp  p K+ L pp pK+L p-exchange K-exchange A.Gasparyan, et al., Eur. Phys. J. A 18 (2003) 305

Slide13: 

The binary reactions gp  K+ L, gp  K+ S0, gp  K+ L(1520) and p-p  K0 L can be described very well within the QGSM assuming dominance of K*-Reggeon exchange and universality of Reggeon couplings Q+ does not follow the universality principle, and the upper limit on its production cross section in pp collisions is about 1 mb at 30-50 GeV. Recently the upper limit on the total gp  K0 Q+ cross section for a narrow resonance at 1540 MeV was found by CLAS collaboration to be 0.8 nb (M.Battaglieri et al., hep-exp/0510061)