EXKALIBUR: Towards a Kaonic Atoms Periodic Table to test Fundamental Interactions

TL;DR

EXKALIBUR aims to systematically perform high-precision X-ray spectroscopy of kaonic atoms across the periodic table to test fundamental interactions, improve kaon mass measurements, and constrain nuclear interaction models.

Contribution

It introduces a comprehensive detector strategy for kaonic atom spectroscopy and outlines plans to enhance fundamental physics tests and nuclear interaction understanding.

Findings

Reduction of charged-kaon mass uncertainty below 10 keV

Creation of a database of nuclear shifts and widths

High-precision tests of bound-state QED in strong fields

Abstract

Kaonic atoms, formed when a negatively charged kaon replaces an electron, provide a unique laboratory to test fundamental interactions at low energies. EXKALIBUR (EXtensive Kaonic Atoms research: from LIthium and Beryllium to URanium) is a program to perform systematic, high-precision X-ray spectroscopy of selected kaonic atoms across the periodic table at the DA$\Phi$NE accelerator at the National Laboratory of Frascati (INFN-LNF). Here, we outline its detector-driven strategy: Silicon Drift Detectors for 10-40 keV transitions in light targets (Li, Be, B, O), CdZnTe detectors for 40-300 keV lines in intermediate-$Z$ systems (Mg, Al, Si, S), and a High-Purity Germanium detector for high-$Z$ atoms (Se, Zr, Ta, Mo, W, Pb), complemented by VOXES, a high-resolution crystal spectrometer for sub-eV studies. EXKALIBUR plans to (i) reduce the charged-kaon mass uncertainty below 10 keV, (ii) produce a database of nuclear shifts and widths to constrain multi-nucleon K$^{-}$-nucleus interaction models, and (iii) provide precision data for testing bound-state QED in strong fields. We summarize the planned measurements and expected sensitivities within DA$\Phi$NE luminosities.