Study of the pd ---> He-3 K+ K- and pd ---> He-3 phi reactions close to threshold

The COSY-MOMO collaboration Bellemann, F. ; Berg, A. ; Bisplinghoff, J. ; et al.
Phys.Rev. C75 (2007) 015204, 2007.
Inspire Record 724774 DOI 10.17182/hepdata.31632

Two--kaon production in proton--deuteron collisions has been studied at three energies close to threshold using a calibrated magnetic spectrograph to measure the final $^3$He and a vertex detector to measure the $K^+K^-$ pair. Differential and total cross sections are presented for the production of $\phi$--mesons, decaying through $\phi\to K^+K^-$, as well as for prompt $K^+K^-$ production. The prompt production seems to follow phase space in both its differential distributions and in its energy dependence. The amplitude for the $pd\to ^3${He}$ \phi$ reaction varies little for excess energies below 22 MeV and the value is consistent with that obtained from a threshold measurement. The angular distribution of the $K^+K^-$ decay pair shows that near threshold the $\phi$--mesons are dominantly produced with polarization $m=0$ along the initial proton direction. No conclusive evidence for $f_0(980)$ production is found in the data.

17 data tables

Total cross section for K+ K- production.

Total cross section for PHI production.

Differential cross section as a function of the excitation energy of the K+ K- pair.