Measurement of $$\phi $$ ϕ meson production in $$p + p$$ p+p interactions at 40, 80 and $$158 \, \hbox {GeV}/c$$ 158GeV/c with the NA61/SHINE spectrometer at the CERN SPS

Abstract

Abstract Results on $$\phi $$ ϕ meson production in inelastic $$p + p$$ p+p collisions at CERN SPS energies are presented. They are derived from data collected by the NA61/SHINE fixed target experiment, by means of invariant mass spectra fits in the $$\phi \rightarrow K^+ K^- $$ ϕ→K+K- decay channel. They include the first ever measured double differential spectra of $$\phi $$ ϕ mesons as a function of rapidity $$y$$ y and transverse momentum $$p_{\text {T}}$$ pT for proton beam momenta of $$80 \, \hbox {GeV}/c$$ 80GeV/c and $$158 \, \hbox {GeV}/c$$ 158GeV/c , as well as single differential spectra of $$y$$ y or $$p_{\text {T}}$$ pT for beam momentum of $$40 \, \hbox {GeV}/c$$ 40GeV/c . The corresponding total $$\phi $$ ϕ yields per inelastic $$p + p$$ p+p event are obtained. These results are compared with existing data on $$\phi $$ ϕ meson production in $$p + p$$ p+p collisions. The comparison shows consistency but superior accuracy of the present measurements. The emission of $$\phi $$ ϕ mesons in $$p + p$$ p+p reactions is confronted with that occurring in $$\mathrm{Pb} + \mathrm{Pb}$$ Pb+Pb collisions, and the experimental results are compared with model predictions. It appears that none of the considered models can properly describe all the experimental observations.