We compute the Λ and Λ‾ global polarization in semi-central heavy-ion collisions modeling the source as consisting of a high-density core and a less dense corona. We show that when more Λs than Λ‾s ...are produced in the corona, and this is combined with a smaller number of Λs coming from the core, as compared to those coming from the corona, an amplification effect for the Λ‾ with respect to that of Λ polarization can occur. This amplification becomes more important for lower collision energies and quantitatively accounts for the Λ and Λ‾ polarizations measured by the STAR beam energy scan.
The study of cosmic rays with underground accelerator experiments started with the LEP detectors at CERN. ALEPH, DELPHI and L3 studied some properties of atmospheric muons such as their multiplicity ...and momentum. In recent years, an extension and improvement of such studies has been carried out by ALICE and CMS experiments. Along with the LHC high luminosity program some experimental setups have been proposed to increase the potential discovery of LHC. An example is the MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles detector (MATHUSLA) designed for searching of Ultra Stable Neutral Particles, predicted by extensions of the Standard Model such as supersymmetric models, which is planned to be a surface detector placed 100 meters above ATLAS or CMS experiments. Hence, MATHUSLA can be suitable as a cosmic ray detector. In this manuscript the main results regarding cosmic ray studies with LHC experimental underground apparatus are summarized. The potential of future MATHUSLA proposal is also discussed.
The ALICE collaboration is proposing a completely new detector, ALICE 3, for operation during the LHC Runs 5 and 6. One of the ALICE~3 subsystems is the Muon IDentifier detector (MID), which has to ...be optimised to be efficient for the reconstruction of \(J/\psi\) at rest (muons down to \(p_{\rm T}\approx1.5\) GeV/\(c\)) for \(|\eta|<1.3\). Given the modest particle flux expected in the MID of a few Hz/cm\(^2\), technologies like plastic scintillator bars (\(\approx1\) m length) equipped with wavelength-shifting fibers and silicon photomultiplier readout, and lightweight Multi-Wire Proportional Chambers (MWPCs) are under investigation. To this end, different plastic scintillator paddles and MWPCs were studied at the CERN T10 test beam facility. This paper reports on the performance of the scintillator prototypes tested at different beam momenta (from 0.5 GeV/\(c\) up to 6 GeV/\(c\)) and positions (horizontal, vertical, and angular scans). The MWPCs were tested at different momenta (from 0.5 GeV/\(c\) to 10 GeV/\(c\)) and beam intensities, their efficiency and position resolutions were verified beyond the particle rates expected with the MID in ALICE 3.
This contribution presents the recent research developments within the Cosmic Ray Extremely Distributed Observatory (CREDO) in the search for resolution of various scientific puzzles, ranging from ...fundamental physical questions to applications like the determination of earthquake precursors. The state-of-the art theoretical, numerical and computational aspects of these phenomena are addressed, as well as recent experimental developments for detection.
Digital analysis of mammographic images is a complementary tool to clinical evaluation, commonly used to identify tumors and/or microcalcifications in mammograms. Recent mammographic equipment, can ...automatically classify them using this methodology. The difficulty in finding and classifying such areas, arise from different factors such as: image acquisition methodology, excess of brightness, similar physiological and radiological properties of tissues, etc. In this work it is proposed that the numerical computations of fractal dimension and entropy are tools that could be used to automatically segment and distinguish malignant tumors and/or microcalcifications in digital mammograms. The study consisted in segment the image in two areas: background and confirmed malignant tumor and/or microcalcification, to which the fractal dimension and entropy values are calculated and it was found the correlation between them. The analysis was performed on a grayscale re-digitized images from images provided locally by hospital for microcalcifications and from public databases for malignant tumors. From these re-digitized images, it was able to give the exact coordinates as the diagnosis provides. For any image, the highest intensity value was located in the tumor and/or microcalcification area, resulting that the fractal dimension had a higher value than the rest of the image, while the entropy value was lower, due to the uniformity of intensities in these areas. To complete this study, it was performed a data analysis with the set of intensities in each area. This allowed to distinguish between the areas of interest according to the value of the intensities, having a value greater than 3 {\sigma}. Finally, it is shown a technique to visually highlight the malignant tumor and/or microcalcification.
In this contribution we study the possibility of the formation of cosmic ray ensembles (CRE) created by the interaction of ultra-high energy (UHE) photons with the magnetic field of the Sun. The lack ...of observation of those UHE and the difficulties for their identification given the current methodologies motivates this study. We performed simulations using the PRESHOWER program in order to simulate the expected extensive air showers which might be spatially correlated generated upon entering the Earth's atmosphere. We found characteristic features like very thing and extremely elongates cascades of secondary photons with their corresponding energies spanning the entire cosmic range spectrum. Shower footprints are as large as hundreds of kilometres. An application of this study is the scenario of gamma-ray emission from the vicinity of the Sun as a result of ultra-high energy photon cascading in the solar magnetic field in order to understand recent observations made by the HAWC and Fermi-LAT observatories.
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