The AMADEUS experiment deals with the investigation of the low-energy kaon-nuclei hadronic interaction at the DAΦNE collider at LNF-INFN, fundamental to respond to longstanding open questions in the ...non-perturbative QCD in the strangeness sector. One of the most interesting aspects is to understand how hadron masses and interactions change in the nuclear environment. The antikaon-nucleon potential is investigated searching for signals from possible bound kaonic clusters, which would imply a strongly attractive antikaon-nucleon potential. AMADEUS step 0 consists in the analysis of 2004/2005 KLOE data, exploring K− absorptions in H, 4He, 9Be and 12C present in setup materials. The status of the various preliminary analyses is presented, together with future perspectives.
In the last decades huge theoretical effort was devoted to the development of consistent theoretical models, aiming to solve the so-called "measurement problem". Among these, the Dynamical Reduction ...Models possess the unique characteristic to be experimentally testable, thus enabling to set experimental upper bounds on the reduction rate parameter λ characterizing these models. By analysing the X-ray spectrum emitted by an isolated slab of Germanium, we set the most stringent limit on the λ parameter up to date.
The AMADEUS experiment has the aim to perform studies of the low energy hadronic interactions of negatively charged kaons with nucleons and nuclei, which are fundamental to solve longstanding open ...questions in the non-perturbative QCD in the strangeness sector. The DAphiNE collider provides a unique source of monochromatic low-momentum kaons, whose nuclear interaction with the materials of the KLOE detector (used as an active target) provide us excellent acceptance and resolution data for K super(-) capture on H, super(4)He, super(9)Be and super(12)C, both at-rest and in-flight. AMADEUS step 0 consisted in the analysis of the 2004-2005 KLOE data. A second step consisted in the implementation in the central region of the KLOE detector of a pure graphite target, providing a high statistic sample of K super(-) super(12)C nuclear captures at rest. For the future, new setups for various dedicated targets are under preparation. The aim of such investigations is to face the major open questions in hadron nuclear physics in the strangeness sector, such as the nature of the E(1405) state and the resonant versus non-resonant yield in nuclear K super(-) capture, the possible existence of kaonic nuclear clusters, strongly related to a quantitative understanding of single versus multi-nucleon K super(-) absorption.
The strong interaction of charged antikaons (K super(-)) with nucleons and nuclei in the low-energy regime is a fascinating topic. The antikaon plays a peculiar role in hadron physics due to the ...strong attraction antikaon-nucleon which is a key question for possible kaonic nuclear bound states. A rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions to low-lying states in light kaonic atoms like kaonic hydrogen and deuterium. After the successful completion of precision measurements on kaonic hydrogen and helium isotopes by SIDDHARTA at DAPhiNE/LNF, new X-ray studies with the focus on kaonic deuterium are in preparation (SIDDHARTA2). In the future with kaonic deuterium data the antikaon-nucleon isospin-dependent scattering lengths can be extracted for the first time. An overview of the experimental results of SIDDHARTA and an outlook to future perspectives in the SIDDHARTA2 experiments in this frontier research field will be given.
The AMADEUS experiment aims to provide unique quality data for
K
−
interaction with nucleons and light nuclei, both at-rest and in-flight (for
K
−
momenta of about 100 MeV). The goal is to solve ...longstanding open issues in the non-perturbative QCD in the strangeness sector, like the nature of the Λ(1405) state, the resonant versus non-resonant yield in nuclear
K
−
capture and the properties of kaonic nuclear clusters which are strongly related to the multi-nucleon absorption processes. We can take advantage of the DA ΦNE collider representing a unique source of monochromatic low-momentum kaons, whose nuclear interaction with the materials of the KLOE detector (used as an active target) furnish us excellent acceptance and resolution data for
K
−
capture on H,
4
He,
9
Be and
12
C, both at-rest and in-flight. AMADEUS step 0 consisted in the analysis of the 2004-2005 KLOE data. A second step consisted in the implementation in the central region of the KLOE detector of a pure graphite target, providing a high statistic sample of
K
−
12
C
nuclear captures at rest. For the future, new setups for various dedicated targets are under preparation.
We measured K-series kaonic hydrogen X-rays in the SIDDHARTA experiment performed at the DAPhiNE electron-positron collider of Laboratori Nazionali di Frascati. With a gaseous hydrogen target of ...density 15 rho sub(STP), preliminary values of the absolute yields, defined as the number of atomic X-rays emitted per kaon stopped inside the target, were determined to be (ProQuest: Formulae and/or non-USASCII text omitted) for K sub( alpha ) transition and (ProQuest: Formulae and/or non-USASCII text omitted) for Ktot, the summation of all the emitted K-series transitions.
Many experiments investigated the possible violation of the Pauli Exclusion Principle (PEP) since its discovery in 1925. The VIP(Violation of the Pauli Principle) experiment tested the PEP by ...measuring the probability for an external electron to be captured and undergo a 2p to 1s transition during its cascading process, with the 1s state already occupied by two electrons. This transition is forbidden by the PEP. The VIP experiment resulted in an upper limit for the probability of PEP violation of 4.7 × 10−29. Currently a setup for the follow up experiment VIP2 is under preparation. The goal of this experiment is to improve the upper limit for the violation of the PEP by two orders of magnitude, by using new X-ray detectors and by implementing an active shielding. We then present the idea of using an analogous experimental technique to search for X rays as a signature of the spontaneous collapse of the wave function, predicted by the continuous spontaneous localization theories, and discuss some very encouraging preliminary results.
The strong-interaction shifts and widths of kaonic hydrogen, deuterium, super(3)He, and super(4)He were measured in the SIDDHARTA experiment. The most precise values of the shift and width of the ...kaonic hydrogen 1s state were determined to be epsilon sub(1)s = -283 + or - 36(stat) + or - 6(syst) eV and Gamma sub(1)s = 541 + or - 89(stat) + or - 22(syst) eV. The upper limit of the kaonic deuterium K alpha yield was found to be < or = 0.39%. In addition, the shifts and widths of the kaonic super(3)He and super(4)He 2p states were determined to be epsilon sub(2)p( super(3)He) = -2 + or - 2(stat) + or - 4(syst) eV and T sub(2)p( super(3)He) = 6 + or - 6(stat) + or - 7(syst) eV; epsilon sub(2)p( super(4)He) = +5 + or - 3(stat) + or - 4(syst) eV and Gamma sub(2)p( super(4)He) = 14 + or - 8(stat) + or - 5(syst) eV. These values are important for the constraints of the low-energy KN interaction in theoretical approaches.
High-precision experiments have been done to test the Pauli exclusion principle (PEP) for electrons by searching for anomalous K-series X-rays from a Cu target supplied with electric current. With ...the highest sensitivity the VIP (VIolation of Pauli Exclusion Principle) experiment set an upper limit at the level of 10−29 for the probability that an external electron captured by a Cu atom can make the transition from the 2p state to a 1s state already occupied by two electrons. In a follow-up experiment at Gran Sasso, we aim to increase the sensitivity by two orders of magnitude. We show proofs that the proposed improvement factor is realistic based on the results from recent performance tests of the detectors we did at Laboratori Nazionali di Frascati (LNF).
SIDDHARTA collaboration performed the highest precision measurement of the shift and width of the kaonic hydrogen 1
s
state induced by the strong interaction at the DAΦNE collider of Laboratori ...Nazionali di Frascati. The result provides vital constraints on the theoretical description of the low-energy
interactions.
PDF
