6,551 research outputs found
Access to particle-particle emitting sources at intermediate energies
The study of nuclear matter under extreme conditions is a very active area in nuclear physics. This study may improve our understanding of the equation of states and liquid-gas phase transitions in nuclear matter as well as the
spectroscopic and dynamic characterization of exotic nuclear systems and reactions. A clear characterization of nuclear interacting systems requires probing the spacetime
properties of various particle-emitting sources and the knowledge of the reaction mechanism. Particle-particle correlations represent a very powerful technique to study emitting sources produced during a reaction. In this work two-proton correlation functions measured in Xe+Au at E = 50MeV/nucleon have been studied. By using angle-averaged two-proton correlation functions and imaging techniques we have estimated some of the basic proprieties, such as the size and the relative contributions provided by two-particle–emitting sources produced in semi-central collisions and characterized by different emission time-scales
Pulse shape discrimination of plastic scintillator EJ 299-33 with radioactive sources
The present study has been carried out in order to investigate about the possibility of using EJ 299-33 scintillator in a multi-detector array to detect neutrons along with light charged particles. In a reaction induced by stable and exotic heavy-ions beams, where copious production of neutrons and other light charged particles occurs, discrimination with low identification threshold of these particles are of great importance. In view of this, EJ 299-33 scintillator having dimension of 3 cm Ă— 3 cm Ă— 3 cm backed by a photomultiplier tube was tested and used under vacuum to detect neutrons, gamma-rays and alpha particles emitted by radioactive sources. Anode pulses from the photomultiplier tube were digitized through GET electronics, recorded and stored in a data acquisition system for the purpose of an off-line analysis. The measurements, under vacuum and low background conditions, show good pulse shape discrimination properties characterized by low identification threshold for neutrons, gamma-rays and alpha particles. The Figures of Merit for neutron-gamma and alpha particles-gamma discriminations have been evaluated together with the energy resolution for gamma-ray and alpha particles
The blue sky of GJ3470b: the atmosphere of a low-mass planet unveiled by ground-based photometry
GJ3470b is a rare example of a "hot Uranus" transiting exoplanet orbiting a
nearby M1.5 dwarf. It is of crucial interest for atmospheric studies because it
is one of the most inflated low-mass planets known, bridging the boundary
between "super-Earths" and Neptunian planets. We present two new ground-based
light curves of GJ3470b gathered by the LBC camera at the Large Binocular
Telescope. Simultaneous photometry in the ultraviolet (lambda_c = 357.5 nm) and
optical infrared (lambda_c = 963.5 nm) allowed us to detect a significant
change of the effective radius of GJ3470b as a function of wavelength. This can
be interpreted as a signature of scattering processes occurring in the
planetary atmosphere, which should be cloud-free and with a low mean molecular
weight. The unprecedented accuracy of our measurements demonstrates that the
photometric detection of Earth-sized planets around M dwarfs is achievable
using 8-10m size ground-based telescopes. We provide updated planetary
parameters, and a greatly improved orbital ephemeris for any forthcoming study
of this planet.Comment: 8 pages, 6 figures, 1 table; accepted for publication in A&
“Using digital media or sleeping … that is the question”. A meta-analysis on digital media use and unhealthy sleep in adolescence
This systematic review with meta-analysis aims to examine the relation between different aspects of digital media use and sleep health patterns. Eligible studies had to be longitudinal and with adolescents' sample. Multiple search strategies were applied until January 28, 2023 in order to identify relevant research published in peer-reviewed journal articles or available grey literature. A final set of 23 studies (N = 116,431; 53.2% female; Mage at baseline = 13.4 years) were included. The quality of the studies, assessed with an adapted version of the Newcastle-Ottawa Scale, was high with a consequent low risk of bias. Meta-analytic results showed that tradi-tional media use (r =-0.33 [-0.44;-0.22]), social media use (r =-0.12 [-0.22;-0.01]), prolonged use (r = -0.06 [-0.11;-0.01]), and dysfunctional use (r =-0.19 [-0.29;-0.09]) are negatively related to adolescents' sleep health at a later time point. Conversely, sleep patterns were not related to social media use (r =-.05 [-0.10; 0.00]) and utilization time (r =-0.13 [-0.30; 0.04]), but they were related to dysfunctional use of media (r = -0.22 [-0.33; -0.10]). Overall, this review highlights the presence of a vicious cycle between digital media use and sleep health in adolescence
A Gaussian approximation of the distributed computing process
The authors propose a refinement of the stochastic model describing the dynamics of the Desktop Grid (DG) project with many hosts and many workunits to be performed, originally proposed by Morozov et al. in 2017. The target performance measure is the mean duration of the runtime of the project. To this end, the authors derive an asymptotic expression for the amount of the accumulated work to be done by means of limit theorems for superposed on-off sources that lead to a Gaussian approximation. In more detail, depending on the distribution of active and idle periods, Brownian or fractional Brownian processes are obtained. The authors present the analytic results related to the hitting time of the considered processes (including the case in which the overall amount of work is only known in a probabilistic way), and highlight how the runtime tail distribution could be estimated by simulation. Taking advantage of the properties of Gaussian processes and the Conditional Monte-Carlo (CMC) approach, the authors present a theoretical framework for evaluating the runtime tail distribution
Constraining Modified Gravity with Euclid
Future proposed satellite missions as Euclid can offer the opportunity to
test general relativity on cosmic scales through mapping of the galaxy weak
lensing signal. In this paper we forecast the ability of these experiments to
constrain modified gravity scenarios as those predicted by scalar-tensor and
theories. We found that Euclid will improve constraints expected from
the PLANCK satellite on these modified gravity models by two orders of
magnitude. We discuss parameter degeneracies and the possible biases introduced
by modified gravity
Factor structure of post-operative quality of recovery questionnaire (QoR-15): An Italian adaptation and validation
Broad-band spectrophotometry of the hot Jupiter HAT-P-12b from the near-UV to the near-IR
The detection of trends or gradients in the transmission spectrum of
extrasolar planets is possible with observations at very low spectral
resolution. Transit measurements of sufficient accuracy using selected
broad-band filters allow for an initial characterization of the atmosphere of
the planet. We obtained time series photometry of 20 transit events and
analyzed them homogeneously, along with eight light curves obtained from the
literature. In total, the light curves span a range from 0.35 to 1.25 microns.
During two observing seasons over four months each, we monitored the host star
to constrain the potential influence of starspots on the derived transit
parameters. We rule out the presence of a Rayleigh slope extending over the
entire optical wavelength range, a flat spectrum is favored for HAT-P-12b with
respect to a cloud-free atmosphere model spectrum. A potential cause of such
gray absorption is the presence of a cloud layer at the probed latitudes.
Furthermore, in this work we refine the transit parameters, the ephemeris and
perform a TTV analysis in which we found no indication for an unseen companion.
The host star showed a mild non-periodic variability of up to 1%. However, no
stellar rotation period could be detected to high confidence.Comment: 13 pages, 6 figures, Accepted for publication in A&
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