Light kaonic atoms spectroscopy provides a unique approach to study the low-energy strong interaction in the strangeness sector. Precise measurements of X-ray emission from light kaonic atoms provide ...valuable information on kaon-nucleus interaction at threshold without the need for extrapolation as required in scattering experiments. The SIDDHARTA-2 experiment at the DAΦNE collider of INFN-LNF is now poised to perform the challenging measurements of the K
−
- d 2p → 1s transition to extract the isospin-dependent antikaonnucleon scattering lengths. To achieve this goal, the background reduction is a crucial factor. This paper provides an overview of the SIDDHARTA-2 Veto-1 system, which uses scintillators outside the vacuum chamber to detect charged particles produced by K− absorption by the nucleus. The arrival time of these particles is correlated with the position where the kaonic atom has been created inside the setup, allowing for the rejection of kaons stopped outside the target cell, which is a critical component for reducing the background and improve the accuracy of the measurement.
The E2 nuclear resonance effect in kaonic atoms occurs when the energy of atomic de-excitation closely matches the energy of nuclear excitation, leading to the attenuation of some X-ray lines in the ...resonant isotope target. This phenomenon provides crucial information on the strong interaction between kaons and nuclei. The only nuclear E2 resonance effect observed so far was in the K
−
−
98
42
Mo isotope, measured by G. L. Goldfrey, G-K. Lum, and C. E. Wiegand at Lawrence Berkeley Laboratory in 1975. However, the 25 hours of data taking were not sufficient to yield conclusive results. In four kaonic Molybdenum isotopes (
94
42
Mo,
96
42
Mo,
98
42
and Mo, and
100
42
Mo), the nuclear E2 resonance effect is expected to occur at the same transition with similar energy values. To investigate this, the KAMEO (Kaonic Atoms Measuring Nuclear Resonance Effects Observables) experiment plans to conduct research on kaonic Molybdenum isotopes at the DAΦNE e
+
e
−
collider during the SIDDHARTA-2 experiment. The experimental strategy involves exposing four solid strip targets, each enriched with one Molybdenum isotope, to negatively charged kaons and using a germanium detector to measure X-ray transitions. In addition, a non-resonant
92
42
Mo isotope solid strip target will be used as a reference for standard non-resonant transitions.
X-ray spectroscopy of kaonic atoms provides a versatile tool to study the strong interaction at low energies via a direct observation of its influence on the ground state of kaonic hydrogen atoms. ...The SIDDHARTA experiment provided precise results on the energy shift and width of the kaonic hydrogen 1s state induced by the strong interaction. To enable the extraction of the antikaon-nucleon scattering lengths a0 and a1, SIDDHARTA-2 aims to determine the energy shift and width in kaonic deuterium with precisions of 30 eV and 75 eV, respectively. This measurement is aggravated by the low kaonic deuterium X-ray yield and a high background environment and will only be possible by implementing a severe upgrade on the SIDDHARTA apparatus.
The VIP-2 (VIolation of the Pauli Exclusion Principle) experiment conducted at the Gran Sasso underground laboratory (LNGS) of INFN is searching for possible tiny violations of standard quantum ...mechanics in copper atoms with extremely high sensitivity. We investigate atomic transitions with precision X-ray spectroscopy in order to test the Pauli Exclusion Principle (PEP) and therefore the spin-statistics theorem. We present the experimental method for the search for "anomalous" (i.e. Pauli-forbidden) X-ray transitions in copper atoms, produced by "new" electrons, which could have a tiny probability to undergo a Pauli-forbidden transition to the 1s ground state already occupied by two electrons. We describe the VIP-2 experimental setup and its recent optimisations. Presently VIP-2 is taking data at LNGS. The goal of VIP-2 is to test PEP for electrons with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10−31 (and using a more elaborate analysis even 10−40). We present current experimental results.
The AMADEUS collaboration aims to provide precise experimental information on the K− strong interaction with nucleons in the low-energy regime. The step 0 of AMADEUS consists in the re-analysis of ...the data collected with the KLOE detector at the DAΦNE collider during the 2004/2005 data taking campaign. The absorptions of low-momentum K−s in the nuclei contained in the detector and the beam pipe setup (H, 4He, 9Be and 12C) are investigated. Information on the K− single and multi-nucleon interactions are extracted from the study of the Λπ− and p correlated production in the final state.
The low-energy, non-perturbative regime of QCD can be studied directly by X-ray spectroscopy of light kaonic atoms. The SIDDHARTA-2 experiment, located at the DAΦNE collider, aims to measure the 2
p
...→ 1
s
transition in kaonic deuterium for the first time to extract the antikaon-nucleon scattering lengths. This measurement is impeded, inter alia, by the low K
−
d X-ray yield. Hence, several updates have been implemented on the apparatus to increase the signal-to-background ratio, which are discussed in detail in this paper: a lightweight gas target cell, novel Silicon Drift Detectors for the X-ray detection with excellent performance, and a veto system for active background suppression. The experiment has undergone a first preparatory run during DAΦNE’s commissioning phase in 2021, concluding with a successful kaonic helium measurement.
The SIDDHARTA (
SIlicon
Drift
Detector for
Hadronic
Atom
Research by
Timing
Application) experiment J. Zmeskal, SIDDHARTA Technical Note IR-2 (2003); C. Curceanu (Petrascu), SID-DHARTA Technical Note ...IR-3 (2003) represents the scientific and technical development of DEAR (
DAΦNE
Exotic
Atom
Research) S. Bianco et al., Rivista del Nuovo Cimento 22 (11) (1999) 1, as part of the program dedicated to exotic atoms at DAΦNE G. Vignola, Proc. of the “5th European Particle Accelerator Conference”, Sitges, Eds. S. Myres et al., Institute of Physics Publishing, Bristol and Philadelphia (1996) 22. The objective consists in an eV precision measurement of the kaonic hydrogen
K
α
line shift and width induced by the strong interaction, and the first measurement of kaonic deuterium. These values will allow a precise determination of antikaon-nucleon scattering lengths and a better understanding of the chiral symmetry breaking scenario in the strangeness sector. DEAR performed the most precise measurement up to now on kaonic hydrogen, at the end of 2002. The SIDDHARTA collaboration is developing a new set of large area, triggerable X-ray Silicon Drift Detectors (SDD), which will improve by 2 orders of magnitude the background rejection, allowing to reach the proposed objectives. The results of DEAR, as well as the state of the art of the new setup are presented.
In the VIP2 VIolation of the Pauli Exlusion Principle (PEP) experiment at the Gran Sasso underground laboratory (LNGS) we are searching for possible violations of standard quantum mechanics ...predictions. With high precision we investigate the Pauli Exclusion Principle and the collapse of the wave function (collapse models). We will present our experimental method of searching for possible small violations of the Pauli Exclusion Principle for electrons, via the search for "anomalous" X-ray transitions in copper atoms, produced by "new" electrons (brought inside a copper bar by circulating current) which could have the probability to undergo Pauli-forbidden transition to the ground state (1 s level) already occupied by two electrons. We will describe the concept of the VIP2 experiment taking data at LNGS presently. The goal of VIP2 is to test the PEP for electrons with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10−31. We will show preliminary experimental results obtained at LNGS and discuss implications of a possible violation.
Mixed Mode Crack Propagation in Iliac Bone Baesu, E.; Iliescu, DM; Radoiu, BV ...
Analele ştiinţifice ale Universităţii "Ovidius" Constanţa. Seria Matematică,
11/2021, Letnik:
29, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Bone is a complex material that can be regarded as an anisotropic elastic composite material. The problem of crack propagation in human bone is analyzed by using a generalization of the maximum ...tensile stress criterion (MTS). The results concern the critical stress for crack propagation and the direction of the crack path in Iliac bone.
The VIP2 (VIolation of the Pauli Exclusion Principle) experiment at the Gran Sasso underground laboratory (LNGS) is searching for possible violations of standard quantum mechanics predictions in ...atoms at very high sensitivity. We investigate atomic transitions with precision X-ray spectroscopy in order to test the Pauli Exclusion Principle (PEP) and therefore the related spin-statistics theorem. We will present our experimental method for the search for "anomalous" (i.e. Pauli-forbidden) X-ray transitions in copper atoms, produced by "new" electrons, which could have tiny probability to undergo Pauli-forbidden transition to the ground state already occupied by two electrons. We will describe the VIP2 experimental setup, which is taking data at LNGS presently. The goal of VIP2 is to test the PEP for electrons with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10−31. We will present current experimental results and discuss implications of a possible violation.
PDF
