Sorakrai Srisuphaphon Role of pentaquark components into  meson production  meson production proton-antiproton annihilation reactions proton-antiproton annihilation reactions

Outline Introduction Introduction The proton wave functions with pentaquark component The proton wave functions with pentaquark component The transition amplitude for  meson production in proton-antiproton annihilation reactions The transition amplitude for  meson production in proton-antiproton annihilation reactions Results and Conclusions Results and Conclusions

Introduction u u u u d d proton Baryons being bound states of three quarks. The proton might contain a substantial strange quark-antiquark component The proton might contain a substantial strange quark-antiquark component Deep Inelastic Scattering The non-zero strange spin of the proton The strangeness magnetic moment can be extrapolated from the strange magnetic form factor Several experimental measurements suggest a positive value for

u u u u d d The presence of a uudss piece in the proton wave function.

The proton wave functions with 5q component with pentaquark

The corresponding spatial state labeled by

spin flavor flavor-spin orbital color orbital-flavor-spin color singlet Construction of multiquark states in group theory.Construction of multiquark states in group theory. Y. Yan, S. Srisuphaphon Y. YanS. Srisuphaphon Prog.Part.Nucl.Phys. 67 (2012)

orbital-flavor-spin color orbital

flavor spin spatial

Transition amplitude The transition amplitude for  meson production in proton-antiproton annihilation reactions

Choosing the plane wave basis for the relative motion of the proton and antiproton ( )

spin-color-flavor weight are geometrical constants depending on the radial parameters

Including the initial state interaction for the atomic state of the system The protonium wave function in momentum space for fixed isospin I

The partial decay width for the transition of the state to the two-meson state statistical weight Branching ratio the partial decay width divided by the total width

Reducing the model dependence Choosing a simplified phenomenological approach that has been applied in studies of two-meson branching ratios in nucleon- antinucleon and radiative protonium annihilation. we use a kinematical phase-space factor of the phenomenological form The initial-state interaction coefficients are related to the probability for a protonium state to have isospin I and spin J

Transition Results The effective strength parameter has to be adjusted to data

Transition

Conclusions The model prediction only in the configuration of is agree well with the experimental data. Branching ratios

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