The kaonic deuterium measurement at J-PARC and DAΦNE will provide a piece of information still missing to the antikaon-nucleon interaction close to threshold, providing valuable information to answer ...one of the most fundamental problems in hadron physics today - to the yet unsolved puzzle of how the hadron mass is generated. For this a new X-ray detector system has been developed to measure the shift and width of the 2p → 1s transition of kaonic deuterium with a precision of 60 eV and 140 eV, respectively.
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,
4
He,
9
Be and
12
C, 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.
The antikaon-nucleon interaction close to threshold provides crucial information on the interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD. In this context, the ...importance of kaonic deuterium x-ray spectroscopy has been well recognized, but no experimental results have yet been obtained due to the difficulty of the measurement. To measure the shift and width of the kaonic deuterium 1s state with an accuracy of 30 eV and 75 eV, respectively, an apparatus is under construction at the Laboratori Nazionali di Frascati. A detailed Monte Carlo simulation has shown that an increase of the signal to background ratio by a factor of ten will be required compared to the successfully performed kaonic hydrogen measurement (SIDDHARTA). Three pillars are essential for the newly developed experimental apparatus: a large area x-ray detector system (consisting of Silicon Drift Detectors), a lightweight cryogenic target system and a veto system, consisting of an outer veto detector (Veto-1) for active shielding and an inner veto detector (Veto-2) for charged particle suppression. For both veto systems, an excellent time resolution is required to distinguish kaons stopping in gas from direct kaon stops in the entrance window or side wall of the target. First test measurements on the Veto-2 system were performed. An average time resolution of (54 ± 2) ps and detection efficiencies of ~ 99 % were achieved.
The kaonic (3)He and (4)He X-rays emitted in the Formula: see text transitions were measured in the SIDDHARTA experiment. The widths of the kaonic (3)He and (4)He 2p states were determined to be ...Formula: see text, and Formula: see text, respectively. Both results are consistent with the theoretical predictions. The width of kaonic (4)He is much smaller than the value of Formula: see text determined by the experiments performed in the 70's and 80's, while the width of kaonic (3)He was determined for the first time.
A magnetic trap for antihydrogen confinement Bertsche, W.; Boston, A.; Bowe, P.D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2006, Volume:
566, Issue:
2
Journal Article
Peer reviewed
The goal of the ALPHA collaboration at CERN is to test CPT conservation by comparing the 1S–2S transitions of hydrogen and antihydrogen. To reach the ultimate accuracy of 1 part in
10
18
, the ...(anti)atoms must be trapped. Using current technology, only magnetic minimum traps can confine (anti)hydrogen. In this paper, the design of the ALPHA antihydrogen trap and the results of measurements on a prototype system will be presented. The trap depth of the final system will be 1.16
T, corresponding to a temperature of 0.78
K for ground state antihydrogen.
High rate production of antihydrogen Amoretti, M; Amsler, C; Bazzano, G ...
Physics letters. B,
01/2004, Volume:
578, Issue:
1-2
Journal Article
Peer reviewed
Open access
We show that antihydrogen production is the dominant process when mixing antiprotons and positrons in the ATHENA apparatus, and that the initial production rate exceeds 300 Hz, decaying to 30 Hz ...within 10 s. A fraction of 65% of all observed annihilations is due to antihydrogen.
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