Search results for "Gamma"
showing 10 items of 3093 documents
The transient gravitational-wave sky
2013
Interferometric detectors will very soon give us an unprecedented view of the gravitational-wave sky, and in particular of the explosive and transient Universe. Now is the time to challenge our theoretical understanding of short-duration gravitational-wave signatures from cataclysmic events, their connection to more traditional electromagnetic and particle astrophysics, and the data analysis techniques that will make the observations a reality. This paper summarizes the state of the art, future science opportunities, and current challenges in understanding gravitational-wave transients.
Multicomponent Exercise Training Combined with Nutritional Counselling Improves Physical Function, Biochemical and Anthropometric Profiles in Obese C…
2020
Aerobics or strength exercise plus diet interventions have been shown to counteract childhood obesity. However, little is known with regard to periodized multicomponent exercise interventions combined with nutritional counselling, which might be less demanding but more enjoyable and respectful of children and adolescents&rsquo
Probing the nature of particle–core couplings in 49Ca with γ spectroscopy and heavy-ion transfer reactions
2011
Neutron rich nuclei around 48Ca have been measured with the CLARA–PRISMA setup, making use of 48Ca on 64Ni binary reactions, at 5.9 MeV/A. Angular distributions of γ rays give evidence, in several transfer channels, for a large spin alignment (≈70%) perpendicular to the reaction plane, making it possible to firmly establish spin and parities of the excited states. In the case of 49Ca, states arising from different types of particle–core couplings are, for the first time, unambiguously identified on basis of angular distribution, polarization and lifetime measurements. Shell model and particle–vibration coupling calculations are used to pin down the nature of the states. Evidence is found fo…
Impact of rare diseases in oral health
2016
Background Rare diseases (RD) are those that present a lower prevalence than 5 cases per 10.000 population. The main objective of this review was to study the effect on oral health in rare diseases, while the secondary objective of the study is theme upgrade. Material and Methods Comparative observational case-control studies were analysed and a systematic review was conducted in PubMed. Each rare disease listed on the statistical data record of the Health Portal of the Ministry of Equality, Health and Social Policies Board of Andalusia was associated with “oral health”. The variables studied included dental, oral mucosa and occlusion alterations, oral pathologies (caries, periodontal disea…
"Table 3" of "Search for pairs of highly collimated photon-jets in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector"
2018
The observed upper limits on the production cross-section times the product of branching ratios for the benchmark signal scenario involving a scalar particle $X$ with narrow width decaying via $X\rightarrow aa\rightarrow 4\gamma$, $\sigma_X\times B(X\rightarrow aa)\times B(a\rightarrow\gamma\gamma)^2$. The limits for $m_{a}$ = 5 GeV and 10 GeV do not cover as large a range as the other mass points, since the region of interest is limited to $ m_{a} < 0.01 \times m_{X}$.
"Table 4" of "Search for pairs of highly collimated photon-jets in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector"
2018
The expected upper limits on the production cross-section times the product of branching ratios for the benchmark signal scenario involving a scalar particle $X$ with narrow width decaying via $X\rightarrow aa\rightarrow 4\gamma$, $\sigma_X\times B(X\rightarrow aa)\times B(a\rightarrow\gamma\gamma)^2$. The limits for $m_{a}$ = 5 GeV and 10 GeV do not cover as large a range as the other mass points, since the region of interest is limited to $ m_{a} < 0.01 \times m_{X}$. Additionally, the expected limits are not provided for a small number of points, indicated with a hyphen, because of a technical failure with the computation.
Room Temperature Instability of E′γ Centers Induced by γ Irradiation in Amorphous SiO2
2008
We study by optical absorption measurements the stability of E'(gamma) centers induced in amorphous silica at room temperature by gamma irradiation up to 79 kGy. A significant portion of the defects spontaneously decay after the end of irradiation, thus allowing the partial recovery of the transparency loss initially induced by irradiation. The decay kinetics observed after gamma irradiation with a 0.6 kGy dose closely resembles that measured after exposure to 2000 pulses of pulsed ultraviolet (4.7 eV) laser light of 40 mJ/cm(2) energy density per pulse. In this regime, annealing is ascribed to the reaction of the induced E'(gamma) centers with diffusing H(2) of radiolytic origin. At higher…
Timing techniques applied to distributed modular high-energy astronomy: the H.E.R.M.E.S. project
2021
The HERMES-TP/SP (High Energy Rapid Modular Ensemble of Satellites -- Technologic and Scientific Pathfinder) is an in-orbit demonstration of the so-called distributed astronomy concept. Conceived as a mini-constellation of six 3U nano-satellites hosting a new miniaturized detector, HERMES-TP/SP aims at the detection and accurate localisation of bright high-energy transients such as Gamma-Ray Bursts. The large energy band, the excellent temporal resolution and the wide field of view that characterize the detectors of the constellation represent the key features for the next generation high-energy all-sky monitor with good localisation capabilities that will play a pivotal role in the future …
Quantum gravity with THESEUS
2021
AbstractIn this paper we explore the possibility to search for a dispersion law for light propagation in vacuo with a sample of Gamma-Ray Bursts detected by the THESEUS satellite. Within Quantum Gravity theories, different models for space-time quantization predict relative discrepancies of the speed of photons w.r.t. the speed of light that (in a series expansion) depend on a given power of the ratio of the photon energy to the Planck energy. This ratio is as small as 10− 23 for photons in the soft γ −ray band (100 keV). The dominant effect is determined by the first significant term of this expansion. If the first order in this expansion is relevant, these theories imply a Lorentz Invaria…
The HERMES-Technologic and Scientific Pathfinder
2020
HERMES-TP/SP (High Energy Rapid Modular Ensemble of Satellites Technologic and Scientific Pathfinder) is a constellation of six 3U nano-satellites hosting simple but innovative X-ray detectors, characterized by a large energy band and excellent temporal resolution, and thus optimized for the monitoring of Cosmic High Energy transients such as Gamma Ray Bursts and the electromagnetic counterparts of Gravitational Wave Events, and for the determination of their positions. The projects are funded by the Italian Ministry of University and Research and by the Italian Space Agency, and by the European Union Horizon 2020 Research and Innovation Program under Grant Agreement No. 821896. HERMES-TP/S…