| The scalar mesons with masses around 1 GeV is one of the prominent topics in modern hadronic physics due to the continuing discussion on the nature of the lightest scalars,the dominant structure of the f0(980) meson has not reached a conclusion.In this thesis,we investigate theoretically the mechanism of f0(980)-meson production for the proton-proton reaction pp→f0PP→K+K-PP with the effective Lagrangian approach.The effective Lagrangian approach with one-pion exchange is used to investigate the scalar f0(980)-meson production in the reaction pp→f0PP→K+K-pp. Considering the contribution from other reaction channels may be important,we include the s-and u-channel exchanges with the intermediate nucleon in our theory model.We calculate the contributions to total cross section and K+K- invariant mass distributions from t- channel with the meson exchange as well as the s- and u-channel exchanges with the intermediate nucleon.The results are compared with the experiments data.Our calculation shows that the u-and t-channels give the dominant contributions;the t-channel is indeed small.The enhancement of K+K- mass spectrum at low energy region indicates that the observation of f0(980)-meson is possible in the reaction pp→K+K-pp near threshold.For the convenience of experimental detecting,the angle distribution is presented as well.The ANKE in COSY as well as the CSR in HIRFL allow for incoming proton beams with kinetic energies of up to 2.8 GeV.With these facilities,it is possible to detect f0(980)-meson in the reaction pp→K+K-pp near threshold.
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