Kaonic atoms measurements with SIDDHARTA-2 Sgaramella, F.; Bazzi, M.; Bosnar, D. ...
Journal of physics. Conference series,
02/2023, Letnik:
2446, Številka:
1
Journal Article
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Abstract
The SIDDHARTA-2 collaboration is aiming to perform the challenging measurement of kaonic deuterium X-ray transitions to the ground state. This will allow to extract the isospin-dependent ...antikaon-nucleon scattering lengths, providing input to the theory of Quantum Chromodynamics (QCD) in the non-perturbative regime with strangeness. This work describes the SIDDHARTA-2 experimental apparatus and presents the results obtained during the commissioning phase realized with kaonic helium measurements. In particular, the first observation of the kaonic helium transitions to the 3s level (M-lines), reported in this work, represents a new source of information to study the kaonic helium cascade process and demonstrates the potential of the SIDDHARTA-2 apparatus, in the view of the ambitious kaonic deuterium measurement.
We aimed to compare cardiac volumes measured with echocardiography (echo) and cardiac magnetic resonance imaging (MRI) in a mixed cohort of healthy controls (controls) and patients with atrial ...fibrillation (AF).
In total, 123 subjects were included in our study; 99 full datasets were analyzed. All the participants underwent clinical evaluation, EKG, echo, and cardiac MRI acquisition. Participants with full clinical data were grouped into 63 AF patients and 36 controls for calculation of left atrial volume (LA Vol) and 51 AF patients and 30 controls for calculation of left ventricular end-diastolic volume (LV EDV), end-systolic volume (ESV), and LV ejection fraction (LV EF).
No significant differences in LA Vol were observed (
> 0.05) when measured by either echo or MRI. However, echo provided significantly lower values for left ventricular volume (
< 0.0001). The echo LA Vol of all the subjects correlated well with that measured by MRI (Spearmen correlation coefficient r = 0.83,
< 0.0001). When comparing the two methods, significant positive correlations of EDV (all subjects: r = 0.55; Controls: r = 0.71; and AF patients: r = 0.51) and ESV (all subjects: r = 0.62; Controls: r = 0.47; and AF patients: r = 0.66) were found, with a negative bias for values determined using echo. For a subgroup of participants with ventricular volumes smaller than 49.50 mL, this bias was missing, thus in this case echocardiography could be used as an alternative for MRI.
Good correlation and reduced bias were observed for LA Vol and EF determined by echo as compared to cardiac MRI in a mixed cohort of patients with AF and healthy volunteers. For the determination of volume values below 49.50 mL, an excellent correlation was observed between values obtained using echo and MRI, with comparatively reduced bias for the volumes determined by echo. Therefore, in certain cases, echocardiography could be used as a less expensive, less time-consuming, and contraindication free alternative to MRI for cardiac volume determination.
In order to notice the influence of slag in the form of powder used as an addition to the cement mass and the substitution of natural aggregates with artificial aggregates from crushed and sorted ...slag, first of all, mixtures of mortars were made for a reduced volume of material. In the mixes design of new road concrete, we have taken into account the results obtained on the most representative mortar mixes. We chose mixtures of mortar with 15% addition of slag powder in the cement mass and those in which the 0/4 mm natural aggregate was substituted in a ratio of 20%, 40%, and 60% with artificial aggregates of crushed and sorted slag from the by-products stockpiles resulting from the process of obtaining the cast iron in the furnaces. The intended objective is to obtain a BcR 5.0 road concrete class that can be used in all categories of traffic. From the results obtained on mortar and concrete mixtures, it can be seen that compressive strengths and flexural tensile strengths remain close both in mortars and in concretes. Also, the results show that the control mixture falls into the BcR5.0 road concrete class and the new mixtures are very close to it.
Worldwide, there is a clear imperativeness to reduce the consumption of non-renewable raw materials. The aim of the research is to obtain new ecological materials with applicability in the ...construction field, but also to efficiently manage these by-products by eliminating it completely and re-introducing it into the economic circuit. We envisaged the use of slag products as a material cementitious characteristics or as artificial aggregates, so that materials embedded in construction produce as little environmental impact as possible. After cooling, the blast furnace slag products was used in the new mortar mixes in two forms: in the form of a powder product milled from the granulated slag, and in the form of an aggregate made of non-granulated slag, sorted to the sized of 0/4 mm. Ground-granulated slag in the form of a powder below 63 μm was used as an addition to the cement mass, and the newly obtained artificial aggregate, sorted to 0/4 mm, was used in various percentages for replacing the natural aggregates in the control mix. The results show that the combined use of slag powder as an addition to the cement mass and artificial slag aggregates, regardless of the percentage of substitution of Natural aggregates in the mortar mortar mix, has led to the development of new mortar mixes with higher compaction than the control mortar. The higher filling rate due to the use of ground slag has influenced the increase of compressive strengths and freeze-thaw strengths from the repeated freeze-thaw action for new cement mortar mixes with blast furnace slag, as compared to the control mortar mix.
Abstract
The nuclear E2 resonance effect occurs when an atomic de-excitation energy is closely matched by a nuclear excitation energy. It produces an attenuation of some of the atomic X-ray lines in ...the resonant isotope target. Investigating the nuclear E2 resonance effect in kaonic atoms, important information about kaon-nucleus strong interaction can be provided. The only
K
−
−
42
98
Mo
nuclear resonance effect was measured by G. L. Goldfrey, G- K. Lum and C. E. Wiegand at Lawrence Berkeley Laboratory, in 1975. The nuclear E2 resonance effect was observed in 25 hours of data taking, not enough to provide a conclusive result. In four kaonic Molybdenum isotopes (
42
94
Mo
,
42
96
Mo
,
42
98
Mo
and
42
100
Mo
), the nuclear E2 resonance effect is expected at the same transition, with similar energy values. The KAMEO (Kaonic Atoms Measuring nuclear resonance Effects Observables) experiment plans to study the E2 nuclear resonance effect in kaonic Molybdenum isotopes at the DAΦNE e
+
e
−
collider, during the SIDDHARTA-2 experiment. The experimental strategy consists of exposing four solid strip targets, each enriched with one Molybdenum isotope, to negatively charged kaons, using a germanium detector for X-ray transition measurements. A further exposure of a non-resonant
42
92
Mo
isotope solid strip target will be used as reference for standard non-resonant transitions.
Hydroxyapatite (HA) thin films for applications in bone prosthesis fabrication were obtained by the radio-frequency magnetron sputtering technique. The depositions were performed from pure HA targets ...on Si and Ti–5Al–2.5Fe alloy substrates. In some experiments a buffer layer of TiN was introduced by pulsed laser deposition before HA coating. The films were deposited in low-pressure argon or Ar–O
2 mixtures at substrate temperatures ranging from 70 to 550 °C. We observed that the films grown at temperatures below 300 °C were prevalently amorphous and contain a small amount of crystalline material. The initial crystalline structure of the target is reconstructed after 1 h films annealing at 550 °C in ambient air. Both the films directly deposited at 550 °C and the ones obtained at room temperature and after that annealed at this temperature—mostly contain the HA phase and exhibit good mechanical characteristics. Weaker peaks of CaO secondary phase are visible in the X-ray diffraction patterns of the films directly grown at 550 °C. Traces of TiO
2 were detected at the interface with the metallic substrate in case of structures grown without the TiN interlayer. All films were smooth, with an average surface roughness of 50 nm. The films grown on TiN interlayer are harder, have higher elasticity modulus values and an increased mechanical resistance at the indenter penetration.
High precision light kaonic atoms X-ray spectroscopy is a unique tool for performing experiments equivalent to scattering at vanishing relative energies, to determine the antikaon–nucleus interaction ...at threshold without the need of extrapolation to zero energy. The SIDDHARTA-2 collaboration is going to perform the first measurement of kaonic deuterium transitions to the fundamental level, which is mandatory to extract the isospin dependent antikaon–nucleon scattering lengths. The SIDDHARTA-2 experiment is presently installed on the DA
Φ
NE collider of INFN-LNF. The preliminary results obtained during the machine commissioning phase in preparation for the kaonic deuterium data taking campaign, together with future perspectives for extreme precision kaonic atoms studies at DA
Φ
NE are presented.
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