Kaonic Atom Measurements with the SIDDHARTA-2 Experiment at the DA$Φ$NE accelerator

D Sirghi; L Abbene; F Artibani; M Bazzi; G Borghi; D Bosnar; M Bragadireanu; A Buttacavoli; M Carminati; A Clozza; F Clozza; L De Paolis; R Del Grande; K Dulski; C Fiorini; I Friščić; C Guaraldo; M Iliescu; M Iwasaki; A Khreptak; S Manti; J Marton; P Moskal; H Ohnishi; K Piscicchia; F Principato; A Scordo; F Sgaramella; M Silarski; F Sirghi; M Skurzok; A Spallone; K Toho; J Zmeskal; C Curceanu

arXiv · 2610.35399

Kaonic Atom Measurements with the SIDDHARTA-2 Experiment at the DA$Φ$NE accelerator

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Abstract

Kaonic atoms provide a unique experimental tool to investigate low-energy strong interactions in systems containing strangeness and, through high-lying transitions, to test bound-state quantum electrodynamics. The SIDDHARTA-2 experiment at the DA$Φ$NE electron--positron collider performs high-precision X-ray spectroscopy of kaonic atoms using low-momentum charged kaons produced in $ϕ$-meson decays. Its primary goal is the study of kaonic deuterium through the measurement of X-ray transitions to the ground state, providing direct access to the low-energy $K^-d$ interaction. In parallel, SIDDHARTA-2 has carried out a broad experimental programme with gaseous targets, including kaonic helium-4 and kaonic neon, as well as measurements of high-$n$ transitions in intermediate-mass kaonic atoms formed in the materials of the experimental setup. In this paper, the main SIDDHARTA-2 measurements and their physics motivations are reviewed, together with the experimental strategy developed for kaonic deuterium and the future perspectives of the collaboration within the EXKALIBUR programme.

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D Sirghi, L Abbene, F Artibani, M Bazzi, G Borghi, D Bosnar, M Bragadireanu, A Buttacavoli, M Carminati, A Clozza, F Clozza, L De Paolis, R Del Grande, K Dulski, C Fiorini, I Friščić, C Guaraldo, M Iliescu, M Iwasaki, A Khreptak, S Manti, J Marton, P Moskal, H Ohnishi, K Piscicchia, F Principato, A Scordo, F Sgaramella, M Silarski, F Sirghi, M Skurzok, A Spallone, K Toho, J Zmeskal, C Curceanu. 2026-10-26. Kaonic Atom Measurements with the SIDDHARTA-2 Experiment at the DA$Φ$NE accelerator. https://arxiv.org/abs/2610.35399

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