Low energy interaction studies of negative kaons in light nuclear targets by AMADEUS

K Piscicchia,C Guaraldo,D Pietreanu,F Ghio,L De Paolis,G Belloti,A M Bragadireanu,M Iliescu,M Bazzi,S Wycech,M Iwasaki,C Curceanu ,M Skurzok ,D Sirghi ,J Márton ,P Moskal ,M Silarski ,L Fabbietti ,A Scordo ,R Del Grande ,M Cargnelli ,C Fiorini ,Arslan Dawood Butt ,S Okada ,P Levi Sandri ,M Miliucci ,F Sirghi ,A Spallone ,O Vázquez Doce ,D Bosnar ,R S Hayano ,E Widmann ,J Zmeskal

doi:10.1051/epjconf/201818101005

Abstract

The AMADEUS collaboration is performing experimental investigations in the sector of the low energy strangeness hadron physics by taking advantage of the DAΦNE collider, which provides a unique source of monochromatic low-momentum kaons and exploiting the KLOE detector as an active target. The K− single and multi-nuclear absorption on H, 4He, 9Be and 12C, both at-rest and in-flight, are studied with the aim to determine the nature of the controversial Λ(1405), the non-resonant hyperon pion formation amplitude below the K̅N threshold, the yield and cross sections of K− multi-nucleon absorptions intimately connected to the antikaon multi-nucleon clusters properties and the K− scattering cross sections on light nuclear targets. These studies have a strong impact on the non-perturbative strangeness QCD with implications ranging from nuclear physics to the equation of state of neutron stars.

Highlights

The AMADEUS (Anti-kaonic Matter At DAΦNE: An Experiment with Unraveling Spectroscopy) [1] experiment is performing a systematic investigation of the hyperon resonances production, and hyperon pion non-resonant formation, in low energy K− hadronic interaction with light nuclear targets (e.g. H, 4He, 9Be and 12C)
Two data sets are under study: one was acquired by the KLOE [3] collaboration during the 2004/2005 data taking campaign, the second was collected by KLOE in collaboration with AMADEUS in the period November-December 2012
The KLOE detector is centered around the interaction region of DAΦNE and is characterised by an acceptance of 98%; it consists of a large cylindrical Drift Chamber (DC)

Summary

The KLOE detector at DAΦNE

DAΦNE (Double Anular Φ-factory for Nice Experiments) is a double ring e+e− collider, designed to work at the center of mass energy of the φ particle; the φ meson decay produces charged kaons with low momentum ( 127 MeV/c) which allows to either stop them, or to explore the products of their low-energy nuclear absorptions. The KLOE detector is centered around the interaction region of DAΦNE and is characterised by an acceptance of 98%; it consists of a large cylindrical Drift Chamber (DC). The chamber is characterized by excellent position and momentum resolutions. The volume ratio (lead/fibers/glue=42:48:10) is optimized for a high light yield and a high efficiency for photons in the range (20-300) MeV/c. Th√e position of the clusters along the fibers can be obtained with a resolution σ ∼ 1.4 cm/ E(GeV). The DC entrance wall composition is 750 μm of carbon fiber and 150 μm of aluminum foil. Dedicated GEANT Monte Carlo simulations of the KLOE apparatus show that out of the total number of kaons interacting in the DC entrance wall, about 81% are absorbed in the carbon fiber component and the remaining 19% in the aluminum foil. The KLOE DC is filled with a mixture of helium and isobutane (90% in volume 4He and 10% in volume C4H10)

Data samples

Particle Identification

Findings

Conclusions and perspectives