Low Mass Dimuon Production in p-A Collisions at $\sqrt{s}=27.5$ GeV with NA60

The NA60 experiment has studied low-mass muon pair production in proton-nucleus collisions with a system of Be, Cu, In, W, Pb and U targets using a 400 GeV/$c$ proton beam at the CERN SPS. The mass spectrum is well described by the superposition of the two-body and Dalitz decays of the light neutral mesons $\eta$, $\rho$, $\omega$, ${\eta }^{\mathrm{\prime }}$ and $\varphi$. A new high-precision measurement of the electromagnetic transition form factors of the $\eta$ and $\omega$ mesons is presented, complemented with a measurement of the temperature parameter of the $\rho$ meson in cold nuclear matter. The $\text{pt}$ spectra for the $\omega$ and $\varphi$ mesons are extracted in the full $\text{pt}$ range accessible, up to $\text{pt}=2$ GeV/$c$. The nuclear dependence of the production cross sections for the $\eta$, $\omega$ and $\varphi$ mesons has been investigated in terms of the power law $\sigma_$\mathrm{p}\mathrm{A}$ \propto $\mathrm{A}$^\alpha$,andthe$\alpha$parameterwasstudiedasafunctionof$\pt$.