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Near threshold KK pair meson production in pp and pd collisions

Vera Grishina (INR RAS, Moscow, Russia) Leonid Kondratyuk (ITEP, Moscow, Russia) 26-30 ноября , 2007 , ИТЭФ, Москва Научная сессия-конференция секции ЯФ ОФН РАН «Физика фундаментальных взаимодействий». Near threshold KK pair meson production in pp and pd collisions. CONTENTS.

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Near threshold KK pair meson production in pp and pd collisions

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  1. Vera Grishina (INR RAS, Moscow, Russia) Leonid Kondratyuk (ITEP, Moscow, Russia) 26-30ноября, 2007, ИТЭФ, Москва Научная сессия-конференция секции ЯФ ОФН РАН «Физика фундаментальных взаимодействий» Near threshold KK pair meson production in pp and pd collisions

  2. CONTENTS • The pp dK+K0 : a0+ (980) resonance and non-resonance contributions • Mechanisms of the pp  da0+ (980) and pp dK+K0 reactions within the Effective Lagrangian Approach. Reggeized Nucleon Exchange Model for the pp  da0+ (980) reaction. Angular and mass distributions of the pp dK+K0 reaction. Extraction of the contributions from the lowest KK partial waves using the experimental data. • K0d mass distribution and K0d final state interaction • f(1020) meson contribution to the pd 3He K+K- reaction and the upper limits on the contributions from the scalar a0 (980)-f0(980) mesons. • On a possibility of the a0 (980)-f0(980) mixing effects.

  3. Two Step Model within the Effective Lagrangian Approach Diagrams for the pp  dK+K0 reaction(KK via a0(980)-resonance, p-exchange Nucleon exchange contribution: U-channel diagram (dominant) a) Nucleon exchange contribution: S-channel diagram (small) b) t-channel meson exchanges: r2 -,b1 -, f1(1285)-,h- c)

  4. Two Step Model & Effective Lagrangian Approach Diagrams for the pp  dK+K0 reaction(non-resonant part) P-K*-p-exchange contribution: P = p0(dominant) P = h(small) a) K+-exchange contribution: (small) b)

  5. Mechanisms of the pp  da0+(980) reaction : stot calculation V.Yu. Grishina, L.A. Kondratyuk, et al., EPJ A 9, 277 (2000); EPJ A 21 (2004) 507 1. Nucleon exchange contribution: a) U-channel diagram (dominant) b) S-channel diagram (small) 2. t-channel meson exchanges: a)r2 -,b1 -(extrapolated from the high energy data on p-p  a00n, using Regge-pole model), b) f1(1285)-,h - (calculated using vertex parameters from the Bonn & Jülich Models)

  6. Total pp  dK+K0 cross section V.Kleber et al., PRL 91, 172304 (2003) /Q=46MeV/ a0 resonance contribution as well as different mechanisms of the non-resonant part are calculated within the TSM V.Yu.Grishina,L.A.Kondratyuk,M.Buescher, et al. EPJ A 21(2004) 507, nucl-th/0402093

  7. pp  da0+ : Two Step Model Quark Gluon String Model Nucleon exchange Diquark and quark exchanges QGSM has been applied to gd  p n at Eg>1GeV V.Yu.Grishina, L.A.Kondratyuk, et al., EPJ A 10, 355 (2001), EPJ A 19, 117 (2004) Reggeized Nucleon Exchange

  8. pp  da0+  dK+K0 cross section:calculated within theQGSM and TSM V.Yu. Grishina, L.A. Kondratyuk, et al., EPJ A 21(2004) 507, nucl-th /0402093

  9. pp dK+K0: angular distribution of the deuteron a0 contribution [(K+K0)s d]P TSM QGSM Non-resonant background [(K+K0)p d]S

  10. pp dK+K0 : angular distribution of the K+K0 pair Q=46 MeV S-wave K+K0: a0+ [(K+K0)s d]P P-wave K+K0: Non-resonant background: p - K*- p - exchange

  11. pp  dK+K0 : P-wave K+K0 production for the p –K*-pexchange G-parity conservation for the ppK+K0 transition amplitude: GKK=(-1)L+I IKK=1, Gpp=+1 L=1 near threshold

  12. pp dK+K0 : mass distribution of the K+K0 system Q=46 MeV s (a0+)=31.5 nb s (backgr.)=6.5 nb Parameters of the Flatté distribution: m0=999 MeV, gph=324 MeV, gKK2/gph2=1.03 are taken from A.Abele et al., Phys. Rev. D 57, 3860 (1998)

  13. pp dK+K0 : K0d mass distribution. Kd FSI(Multiple Scattering Approach) We used only sets of the KN scattering lengths to satisfy: Im a(Kd) < 1.3 fm found by A. Sibirtsev et al., Phys. Lett. B 601 (2004) 132 Q=46 MeV The K0d FSI effect is important only for the [(K0 d)s K+]P partial wave

  14. pp dK+K0:A.Dzyuba, et al. EPJ A 29(2006) 245

  15. pp dK+K0 Near threshold amplitude analysis

  16. pp dK+K0 Q=104,7 MeV 95±4% of the KK in s-wave, But Flatté amplitude for a0+(980) was not included into fit

  17. pp dK+K0 Q=47,4 MeV 89±4% of the KK in s-wave

  18. pd  3He K+Kˉ The data are from the experiment by MOMO at COSY-Jülich proton Accelerator, F. Bellemann at al, Phys. Rev. C 75, 015204(2007): stot=9,5 nb, f part is 16%

  19. pd  3He K+Kˉ : Q=40,6 MeV Result of the fit with a0(980) Included (the Flatté amplitude parameters are taken from literature) a0(980)< 20% f [%]

  20. pd  3He K+Kˉ : Q=40,6 MeV Result of the fit with f0(980) Included (the Flatté amplitude parameters are taken from literature) f0(980)< 10%

  21. The KK loop diagram for the f0(980)-a0(980) mixing amplitude K+(K0) f0(980) a0(980) +(-) The effect is based on 4 MeV difference of the charged and neutral kaon masses N.N. Achasov 1979 K–(K0) the overall sign

  22. The f0(980)-a0(980) mixing effectcalculated for different parameters for f0(980): f0 BES Collaboration (China) 2005 E791 Collaboration 2001 Opal Collaboration (CERN) 1998 % The a0(980) Flatte-like propagator modulus squared taken from analysis by Crystal Barrel Colaboration A.Abele et al., Phys. Rev. D 57, 3860 (1998)

  23. Conclusions There are theoretical arguments and experimental indications of the a0 (980) contribution to the pp  d K+K0 upper limits on a0 (980) and f0(980) in pd  3He K+Kˉ

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