110445306
The distributed production system of the SuperB project: description and results
The SuperB experiment needs large samples of MonteCarlo simulated events in order to finalize the detector design and to estimate the data analysis performances. The requirements are beyond the capabilities of a single computing farm, so a distributed production model capable of exploiting the existing HEP worldwide distributed computing infrastructure is needed. In this paper we describe the set of tools that have been developed to manage the production of the required simulated events. The production of events follows three main phases: distribution of input data files to the remote site Storage Elements (SE); job submission, via SuperB GANGA interface, to all available remote sites; output files transfer to CNAF repository. The job workflow includes procedures for consistency checking, monitoring, data handling and bookkeeping. A replication mechanism allows storing the job output on the local site SE. Results from 2010 official productions are reported.
14338309
The BaBar Mini
BaBar has recently deployed a new event data format referred to as the Mini. The mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per event. The Mini currently uses Objectivity persistence, and it is being ported to use Root persistence. The Mini contains enough information to support detailed detector studies, while remaining small and fast enough to be used directly in physics analysis. Mini output is customizable, allowing users to both truncate unnecessary content or add content, depending on their needs. The Mini has now replaced three older formats as the primary output of BaBar event reconstruction. A reduced form of the Mini will soon replace the physics analysis format as well, giving BaBar a single, flexible event data format covering all its needs.
115714674
BaBar results on sin(2beta) and B0 oscillations
61135312
Portable software for distributed readout controllers and event builders in FASTBUS and VME
We report on software developed as part of the PAN-DA system to support the functions of front end readout controllers and event builders in multiprocessor, multilevel, distributed data acquisition systems. For the next generation data acquisition system we have undertaken to design and implement software tools that are easily transportable to new modules. The first implementation of this software is for Motorola 68K series processor boards in FASTBUS and VME and will be used in the Fermilab accelerator run at the beginning of 1990. We use a Real Time Kernel Operating System. The software provides general connectivity tools for control, diagnosis and monitoring. 17 refs., 7 figs.
17140866
Extracting longitudinal shower development information from crystal calorimetry plus tracking
arXiv:0711.1593v2 [physics.ins-det] 11 Apr 2008 Extracting longitudinal shower development information from crystal calorimetry plus tracking D.N. Brown a , J. Ilic b , G.B. Mohanty b a Lawrence b Department Berkeley National Laboratory, Berkeley, California 94720, USA of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom Abstract We present an approach to derive longitudinal shower development information from the longitudinally unsegmented B A B AR electromagnetic calorimeter by using tracking information. Our algorithm takes advantage of the good three- dimensional tracking resolution of B A B AR , which provides an independent geometric constraint on the shower as measured in the B A B AR crystal calorimeter. We show that adding the derived longitudinal shower development information to standard particle identiﬁcation algorithms signiﬁcantly improves the low-momentum separation of pions from electrons and muons. We also verify that the energy dependence of the electromagnetic shower development we measure is consistent with the prediction of a standard electromagnetic shower model. Key words: Particle Identiﬁcation, Longitudinal Shower Depth, Electromagnetic Calorimetry, Tracking PACS: 29.40.Gx, 29.40.Vj, 07.05.Kf 1. Introduction In present-day nuclear and particle physics ex- periments, inorganic scintillating crystals, such as NaI(Tl) and CsI(Tl), are often used to construct electromagnetic calorimeters when a precise mea- surement of the energy is required [1]. Crystal calorimeters can be ﬁnely segmented in the dimen- sion transverse to the shower development without sacriﬁcing energy resolution, thus providing a good measurement of the lateral shower development. However, engineering and energy resolution consid- erations prevent ﬁnely segmenting crystal calorime- ters along the direction of shower development. Both lateral and longitudinal shower development information are useful in charged particle identi- Email addresses: Dave Brown@lbl.gov (D.N. Brown), J.Ilic@warwick.ac.uk (J. Ilic), G.B.Mohanty@warwick.ac.uk (G.B. Mohanty). Preprint submitted to Elsevier Science ﬁcation (PID) algorithms, particularly in electron identiﬁcation. Because crystal calorimeters cannot provide direct longitudinal shower development in- formation, they lose an important input to particle identiﬁcation. In this paper, we present a technique in which longitudinal shower development information is indirectly extracted from a longitudinally unseg- mented crystal calorimeter in conjunction with a precise tracking system. This technique was devel- oped for use with the B A B AR [2] detector, but it can be applied at any detector which combines crystal calorimetry and precision tracking. It exploits the fact that B A B AR has a tracking system capable of precisely determining the three-dimensional trajec- tory of charged particles, and the fact that these trajectories are not in general collinear with the crystal axes. A similar algorithm has previously been used for sampling calorimeters with ﬁne lateral segmentation [3]. 11 April 2008
121719814
An electromagnetic calorimeter for the small angle regions of the collider detector at Fermilab
Two large electromagnetic calorimeters have been built for the Collider Detector at Fermilab (CDF). These have been designed for use in the small angle regions in both the proton and the antiproton beam directions. Each calorimeter consists of 30 sampling layers of proportional tube chambers with cathode pad readout separated by lead sheets for a total thickness of 25.5 radiation lengths. Each proportional tube chamber is constructed using a novel technique in which the insulating side of the cathode pad board is bonded to the proportional tube walls using resistive epoxy. The measured energy response of the calorimeter is linear up to 160 GeV, and the measured energy resolution, σEE, is approximately 25%√E + 0.5%. The position resolution for single electrons varies between 1 and 4 mm depending on location in the calorimeter. The calorimeter offers good eπ discrimination, where typically the pion misidentification probability ƒπ → e < 0.5% for an electron identification efficiency ϵ90%.
119488847
Scintillating fiber hodoscope for a bremsstrahlung luminosity monitor at an electron–positron collider
The performance of a scintillating fiber (2 mm diameter) position sensitive detector (4.8×4.8 cm2 active area) for the single bremsstrahlung luminosity monitor at the VEPP‐2M electron‐positron collider in Novosibirsk, Russia is described. Custom electronics is triggered by coincident hits in the Y and Y planes of 24 fibers each, and reduces 64 photomultiplier signals to a 10‐bit (X,Y) address. Hits are accumulated (10 kHz) in memory and display (few Hz) the VEPP‐2M collision vertex. Fitting the strongly peaked distribution (∼3–4 mm at 1.6 m from the collision vertex of VEPP‐2M) to the expected QED angular distribution yields a background in agreement with an independent determination of the VEPP‐2M luminosity.
123343445
Status of the g-2 experiment at BNL
The muon g-2 experiment at Brookhaven has successfully completed two exploratory runs using pion injection and direct muon injection for checkout and initial data taking. The main components of the experiment, which include the pion beam line, the superconducting storage ring and inflector magnets, the muon kicker and the lead-scintillating fiber calorimeters have been satisfactorily commissioned. First results on the anomalous magnetic moment of the positive muon from pion injection are in good agreement with previous experimental results for a(mu+) and a(mu-) from CERN and of comparable accuracy (13 ppm). Analysis of the 1998 muon injection run is in progress and expected to improve the precision to about 4 ppm. A first production run is scheduled for January 1999 with the goal of reaching the 1 ppm error level.
16002528
Testing the LIGO inspiral analysis with hardware injections
Injection of simulated binary inspiral signals into detector hardware provides an excellent test of the inspiral detection pipeline. By recovering the physical parameters of an injected signal, we test our understanding of both instrumental calibration and the data analysis pipeline. We describe an inspiral search code and results from hardware injection tests and demonstrate that injected signals can be recovered by the data analysis pipeline. The parameters of the recovered signals match those of the injected signals.
8628997
Searching for gravitational waves from binary inspirals with LIGO
We describe the current status of the search for gravitational waves from inspiralling compact binary systems in LIGO data. We review the result from the first scientific run of LIGO (S1). We present the goals of the search of data taken in the second scientific run (S2) and describe the differences between the methods used in S1 and S2.
119440102
Conformal invariance and the conformal-traceless decomposition of the gravitational field
Einstein’s theory of general relativity is written in terms of the variables obtained from a conformaltraceless decomposition of the spatial metric and extrinsic curvature. The determinant of the conformal metric is not restricted, so the action functional and equations of motion are invariant under conformal transformations. With this approach the conformal-traceless variables remain free of density weights. The conformal invariance of the equations of motion can be broken by imposing an evolution equation for the determinant of the conformal metric g. Two conditions are considered, one in which g is constant in time and one in which g is constant along the unit normal to the spacelike hypersurfaces. This approach is used to write the Baumgarte-Shapiro-Shibata-Nakamura system of evolution equations in conformally invariant form. The presentation includes a discussion of the conformal thin sandwich construction of gravitational initial data, and the conformal flatness condition as an approximation to the evolution equations.