The Physics Case for the $\sqrt{s_{NN}}\approx 10$ GeV Energy Region

There are indications that the beam energy region $\sqrt{s_{NN}}\approx 10$ GeV for heavy-ion collisions is an interesting one. The final state has the highest net baryon density at this beam energy. A transition from a baryon dominated to a meson dominated final state takes place around this beam energy. Ratios of strange particles to mesons show clear and pronounced maxima around this beam energy. The theoretical interpretation can be clarified by covering fully this energy region. In particular the strangeness content needs to be determined, data covering the full phase space ($4\pi$) would be helpful to establish the properties of this energy region.