Modification of the strange meson properties in nuclear matter

To make progress in understanding the properties of the strange mesons with open (K−) and hidden (ϕ) strangeness in the nuclear medium, the measurements of the production of K+K− pairs with invariant masses corresponding to both the ϕ and non-ϕ regions in proton collisions with C, Cu, Ag, and Au targets at an incident beam energy of 2.83 GeV were recently performed by the ANKE Collaboration at COSY. The data from the ϕ region of invariant masses provide information on the momentum dependence of the ϕ nuclear transparency ratio and the in-medium ϕ meson width over the momentum range of 0.6-1.6 GeV/c. Analysis of the data from the non-ϕ region of K+K− invariant masses, where differential cross sections for pair production on the four targets were obtained as functions of the laboratory K− momentum, allows to draw the conclusion of the strength of the K−-nuclear potential

Modification of the strange meson properties in nuclear matter

To make progress in understanding the properties of the strange mesons with open (K−) and hidden (ϕ) strangeness in the nuclear medium, the measurements of the production of K+K− pairs with invariant masses corresponding to both the ϕ and non-ϕ regions in proton collisions with C, Cu, Ag, and Au targets at an incident beam energy of 2.83 GeV were recently performed by the ANKE Collaboration at COSY. The data from the ϕ region of invariant masses provide information on the momentum dependence of the ϕ nuclear transparency ratio and the in-medium ϕ meson width over the momentum range of 0.6-1.6 GeV/c. Analysis of the data from the non-ϕ region of K+K− invariant masses, where differential cross sections for pair production on the four targets were obtained as functions of the laboratory K− momentum, allows to draw the conclusion of the strength of the K−-nuclear potential

Modification of the strange meson properties in nuclear matter

To make progress in understanding the properties of the strange mesons with open (K−) and hidden (ϕ) strangeness in the nuclear medium, the measurements of the production of K+K− pairs with invariant masses corresponding to both the ϕ and non-ϕ regions in proton collisions with C, Cu, Ag, and Au targets at an incident beam energy of 2.83 GeV were recently performed by the ANKE Collaboration at COSY. The data from the ϕ region of invariant masses provide information on the momentum dependence of the ϕ nuclear transparency ratio and the in-medium ϕ meson width over the momentum range of 0.6-1.6 GeV/c. Analysis of the data from the non-ϕ region of K+K− invariant masses, where differential cross sections for pair production on the four targets were obtained as functions of the laboratory K− momentum, allows to draw the conclusion of the strength of the K−-nuclear potential

Momentum dependence of hadronic production of the φ-meson and its width in nuclear matter

Information on the properties of the ϕ meson in the nuclear environment has been derived from its production in proton collisions with C, Cu, Al, and Au nuclear targets. The experiment was carried out with 2.83 GeV protons at the Cooler Synchrotron COSY, with the ϕ being detected via its K  +  K  − decay using the ANKE magnetic spectrometer. The measured dependence of the production cross section on the nuclear mass number has been compared with calculations within three different nuclear models. These suggest a significant broadening of the width of the ϕ in medium relative to its vacuum value. The ANKE results obtained in the momentum range 0.6 < p ϕ  < 1.6 GeV/c are compared with data from photoproduction experiments at slightly higher momenta