Search results for "methodologies"
showing 10 items of 2106 documents
The ATLAS TileCal read-out drivers signal reconstruction
2009
TileCal is the hadronic calorimeter of the ATLAS experiment at the LHC collider at CERN. The Read-Out Drivers (ROD) are the core of the off-detector electronics. The main components of the RODs are the Digital Signal Processor (DSP) placed on the Processing Unit (PU) dautherboards. This paper describes the DSP code and its performance with calibration and real data. The code is divided into two different parts: the first part contains the core functionalities and the second one the reconstruction algorithms. The core acts as an operating system and it controls the configuration, the data reception, transmission, online monitoring and the synchronization between front-end data and the Trigge…
Analysis of the irradiance along different paths in the image space using the Wigner distribution function
1997
Abstract The intensity distribution along different paths in the image space of an optical system is described in a two-dimensional phase-space domain in terms of the Wigner distribution function. This approach is useful for an efficient analysis of the performance of optical imaging systems suffering from spherical aberration. The good performance of the method is shown in some numerical simulations.
All-optical super resolved and extended depth of focus imaging with random pinhole array aperture
2008
In this paper, we present a novel approach which allows combining super resolved imaging with extended depth of focus while the result is obtained by all-optical means and no digital processing is required. The presented approach for the super resolved imaging includes attaching a random pinhole array plate to the aperture plane of the imaging system. The energetic efficiency of the system is high and it is much larger than an imaging through a single pinhole which also has extended depth of focus. The super resolving result is obtained by mechanic scanning of the aperture plane with the random plate.
Shock capturing methods in 1D numerical relativity
2008
A numerical code is presented which uses modern shock capturing methods to evolve spherically symmetric perfect fluid space-times. Harmonic slicing is used to ensure singularity avoidance, which is crucial in strong field situations. Some tests are presented, including an application to the stellar collapse problem.
The $\varepsilon$-form of the differential equations for Feynman integrals in the elliptic case
2018
Feynman integrals are easily solved if their system of differential equations is in $\varepsilon$-form. In this letter we show by the explicit example of the kite integral family that an $\varepsilon$-form can even be achieved, if the Feynman integrals do not evaluate to multiple polylogarithms. The $\varepsilon$-form is obtained by a (non-algebraic) change of basis for the master integrals.
Functional and local renormalization groups
2015
We discuss the relation between functional renormalization group (FRG) and local renormalization group (LRG), focussing on the two dimensional case as an example. We show that away from criticality the Wess-Zumino action is described by a derivative expansion with coefficients naturally related to RG quantities. We then demonstrate that the Weyl consistency conditions derived in the LRG approach are equivalent to the RG equation for the $c$-function available in the FRG scheme. This allows us to give an explicit FRG representation of the Zamolodchikov-Osborn metric, which in principle can be used for computations.
RG flows of Quantum Einstein Gravity in the linear-geometric approximation
2014
We construct a novel Wetterich-type functional renormalization group equation for gravity which encodes the gravitational degrees of freedom in terms of gauge-invariant fluctuation fields. Applying a linear-geometric approximation the structure of the new flow equation is considerably simpler than the standard Quantum Einstein Gravity construction since only transverse-traceless and trace part of the metric fluctuations propagate in loops. The geometric flow reproduces the phase-diagram of the Einstein-Hilbert truncation including the non-Gaussian fixed point essential for Asymptotic Safety. Extending the analysis to the polynomial $f(R)$-approximation establishes that this fixed point come…
Search for new physics using QUAERO: A general interface to D0 Event data
2001
We describe Quaero, a method that i) enables the automatic optimization of searches for physics beyond the standard model, and ii) provides a mechanism for making high energy collider data generally available. We apply Quaero to searches for standard model WW, ZZ, and ttbar production, and to searches for these objects produced through a new heavy resonance. Through this interface, we make three data sets collected by the D0 experiment at sqrt(s)=1.8 TeV publicly available.
Single-shot color digital holography based on the fractional Talbot effect
2011
We present a method for recording on-axis color digital holograms in a single shot. Our system performs parallel phase-shifting interferometry by using the fractional Talbot effect for every chromatic channel simultaneously. A two-dimensional binary amplitude grating is used to generate Talbot periodic phase distributions in the reference beam. The interference patterns corresponding to the three chromatic channels are captured at once at different axial distances. In this scheme, one-shot recording and digital reconstruction allow for real-time measurement. Computer simulations and experimental results confirm the validity of our method.
The DEPFET pixel detector for the Belle II experiment at Super KEKB
2014
A pixel detector built with the DEPFET technology will be used for the two innermost layers of the Belle II experiment at the e + e SuperKEKB collider at KEK. The physics goals of the experiment impose challenging requirements to the design of the pixel detector in terms of performance, material budget and power consumption. The DEPFET technology has proven to be a suitable solution for the Belle II requirements and has been chosen as the baseline for the detector. This paper reviews the DEPFET pixel detector for Belle II and the various system aspects that have driven its final design.