Jun 22 – 27, 2023
Auditorium Maximum
Europe/Warsaw timezone

Hypernuclear halos

Jun 26, 2023, 3:25 PM
Medium lecture hall (B) (Auditorium Maximum)

Medium lecture hall (B)

Auditorium Maximum


Simone Velardita (Technische Universität Darmstadt)


The phenomenon of neutron halos was discovered in light-mass nuclei at the limit of nuclear existence. Historically, $^{11}$Li was the first halo nucleus discovered from interaction cross section measurements by Tanihata et al. Understood as a universal feature of bound baryonic systems, halos are also predicted in hypernuclei, while no direct experimental evidence has been obtained so far. The lightest predicted hypernuclear halo is the hypertriton, $^3_\Lambda $H, where predictions for its matter radius vary between 4–10 fm, depending on the binding-energy.

The HYDRA (HYpernuclei Decay at R3B Apparatus) physics program within the R$^{3}$B collaboration will focus on studying the decay spectroscopy of hypernuclei produced from heavy-ion collisions at GSI/FAIR. The program aims at measuring with high resolution the in-flight pionic decay of light- and medium-mass hypernuclei. To achieve that, a pion tracker is conceived as a time projection chamber (TPC) inside the GLAD magnet of the R3B setup. The first experiment of HYDRA, foreseen in 2025, aims at the matter radius of $^3_\Lambda $H from the measurement of its interaction cross section (ICS). Due to the low production cross section of hypernuclei and their very short lifetime, a direct measurement of their ICS is difficult. To overcome that, a new experimental method has been developed, adapting the ICS measurement to hypernuclei which will allow to make a conclusion on the halo or non-halo character of $^3_\Lambda $H. The method and its sensitivity to the ICS, investigated with detailed realistic simulations of the experimental conditions will be presented.

Collaboration R3B

Primary author

Simone Velardita (Technische Universität Darmstadt)


Alexandre Obertelli (Technische Universität Darmstadt) Alexandru Enciu (Technische Universität Darmstadt) Liancheng Ji (Technische Universität Darmstadt) Meytal Duer (Technische Universität Darmstadt) Yelei Sun (Technische Universität Darmstadt)

Presentation materials