Erlangen 2026 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HK: Fachverband Physik der Hadronen und Kerne
HK 27: Poster Session
HK 27.25: Poster
Wednesday, March 18, 2026, 16:15–18:30, Redoutensaal
φ Production at subthreshold energies at HADES — •Felix Fritzemeier — Max-von-Laue-Straße 1, 60438 Frankfurt am Main
HADES explores the region of the phase diagram of strongly interacting matter with the
highest net-baryon densities accessible in heavy-ion collisions.
In this regime, sub-threshold strangeness production is a particularly sensitive probe of the energy sharing inside the fireball. The φ-meson is especially interesting at
deep subthreshold energies: the φ/K− ratio is observed to increase towards lower
√sNN, and a successful reconstruction of φ mesons in Au+Au at
√sNN = 2.24 GeV (well below the free production threshold of
√sNN = 2.90 GeV) would provide the lowest-energy φ data point
measured so far.
The analysis is highly challenging, but as a first step we achieve good agreement
between same-event and mixed-event invariant-mass distributions, demonstrating control
over the combinatorial background. This establishes a solid basis for further studies
with the next-generation calibrated data set and an improved signal-to-background ratio
through enhanced charged-kaon identification.
Keywords: HADES; heavy-ion collisions; high net-baryon density; $\phi$-Meson; sub threshold production