199,152 research outputs found
Monochromatic single photon events at the muon collider
No full textThe cross section for lepton pair annihilation into a photon and a dark photon or an axionlike particle is constant for large center-of-mass energies because some of the portal operators coupling the Standard Model and dark sector are proportional to the energy. Feebly coupled though they are, these portal operators will be enhanced by the large center-of-mass energy made available by a muon collider and thus provide the ideal example of possible physics beyond the Standard Model to be studied with such a machine. We discuss the characteristic signature of the presence of these operators: monochromatic single photon events for the two benchmarks of having center-of-mass energies of 3 and 10 TeV and integrated luminosity of, respectively, 1 and 10 ab-1. We find that an effective scale of the portal operator as large as Λ=112 TeV for an axionlike particle and Λ=141 TeV for a dark photon can be separated from the background with a confidence level of 95% in the first benchmark; these interaction scales can be raised to Λ=375 and 459 TeV in the case of the second benchmark. The signal for the pseudoscalar particle can be distinguished from that of the spin-1 with about 500 events. The response of the detector to high-energy photons is examined.The cross section for lepton pair annihilation into a photon and a dark photon or an axion-like particle is constant for large center-of-mass energies because some of the portal operators coupling Standard Model and dark sector are proportional to the energy. Feebly coupled though they are, these portal operators will be enhanced by the large center-of-mass energy made available by a muon collider and thus provide the ideal example of possible physics beyond the Standard Model to be studied with such a machine. We discuss the characteristic signature of the presence of these operators: mono-chromatic single photon events for the two benchmarks of having center-of-mass energies of 3 and 10 TeV and integrated luminosity of, respectively, 1 and 10 ab. We find that an effective scale of the portal operator as large as TeV for an axion-like particle and TeV for a dark photon can be separated from the background with a confidence level of 95% in the first benchmark; these interaction scales can be raised to TeV and TeV in the case of the second benchmark. The signal for the pseudo scalar particle can be distinguished from that of the spin-1 with about 500 events. The response of the detector to high-energy photons is examined
Aero-acoustics in a tangential blower: validation of the CFD flow distribution using advanced PIV Techniques
No full text
Characterization of the velocity and heat transfer fields in an internal cooling channel with high blockage ratio
No full textThe present experimental study is dealing with a detailed aero/thermal investigation of the turbulent flow inside a rib-roughened turbine blade cooling channel by means of Particle Image Velocimetry (PIV) and Liquid Crystal Thermometry (LCT). The main objectives of the paper are to provide detailed information about the behaviour of such a complicated flow, useful for its understanding, and to create a wide and reliable data base for numerical code validation. The measurements are carried out at engine representative Reynolds number within a scaled up model of a stationary straight cooling channel, with turbulent promoters (or ribs) installed on one wall. The ribs have an angle of attack of 90 deg with respect to the “mean” flow direction; their blockage ratio is equal to 30%. Detailed wall heat transfer distributions are presented. The main time-averaged flow features are identified and quantified; a number of rms characteristics are put in evidence and compared to the heat transfer distributions
Aero-acoustic in a tangential blower: validation of the CFD flow distribution using advanced PIV techniques
No full textNoise reduction is of increasing importance in the community.
Consequently, the development of aero-acoustics is gaining special focus
within industry. Computational Aero-Acoustics (CAA), the coupling of
Computational Fluid Dynamics (CFD) and Computational Acoustics (CA), is
being used in the design and assessment of a range of products from
HVAC ducts to domestic appliances.
The process for carrying out an Aero-Acoustic simulation begins with
the solution of the transient flow dynamics in order to compute accurately
the pressure fluctuations at a number of points in the computational
domain. These fluctuations are passed to the acoustic code to propagate
the acoustic waves through the system and determine its acoustic
signature. To minimize errors in the acoustic propagation analysis it is thus
essential that accurate predictions of the noise sources be obtained.
This paper concentrates on the CFD part of the aero-acoustic
simulation. The case considered has been taken from the European
project DESTINY:3 and comprises a tangential blower located inside a
complex duct system. Air is drawn into the fan through two inlets and exits
through a single duct. The computational methodology and flow field
predictions are presented and compared to experimental PIV data. The
numerical predictions were found to be in good agreement with the
experimental data, reproducing the asymmetries in the flow field
La strategia del ragno, ovvero la rivincita di Aracne. Fortuna tardo-antica (Sidonio Apollinare, Claudiano) di un mito ovidiano
No full textTGFβ1 regulation and collagen-release-independent connective tissue re-modelling by the ruthenium complex NAMI-A in solid tumours
No full textL'etimologia di aletheia e la concezione platonica della verità
No full textDiscussione dell'etimologia heideggeriana di aletheia in relazione a testi greci antichi e della concezione ontologica della verità in Platon
A statistical prescription to estimate properly normalized distributions of different particle species
No full textWe describe a statistical method to estimate the composition of a sample of particle tracks in terms of the species of these particles. We consider the case when the particle identification information strongly depends on some kinematical variables, whose distributions are poorly known and different for each particle species. We show that the proposed procedure provides a properly normalized estimate of the unknown distributions with minimal assumption on their functional form. Moreover, we show that the method can be generalized to any kinematical distribution of the particles. Published by Elsevier B.V
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