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.
37689024
Lowest order hadronic contribution to the muon g-2 value with systematic error correlations.
We have performed a new evaluation of the hadronic contribution to {ital a}{sub {mu}}=({ital g}{minus}2)/2 of the muon with explicit correlations of systematic errors among the experimental data on {sigma}({ital e}{sup +}{ital e}{sup {minus}}{r_arrow}hadrons). Our result for the lowest order hadronic vacuum polarization contribution is {ital a}{sub {mu}}{sup had}=702.6(7.8)(14.0){times}10{sup {minus}10} where the first error is statistical and the second is systematic. The total systematic error contributions from below and above {radical}{ital s}=1.4 GeV are (13.1){times}10{sup {minus}10} and (5.1){times}10{sup {minus}10}, respectively, and are hence dominated by the low energy region. Therefore, new measurements on {sigma}({ital e}{sup +}{ital e}{sup {minus}}{r_arrow}hadrons) below 1.4 GeV can significantly reduce the total error on {ital a}{sub {mu}}{sup had}. In particular, the effect on the total errors of new hypothetical data with 3{percent} statistical and 0.5{endash}1.0{percent} systematic errors is presented. {copyright} {ital 1996 The American Physical Society.}
119648296
FastSim: A Fast Simulation for the SuperB Detector
We have developed a parameterized (fast) simulation for detector optimization and physics reach studies of the proposed SuperB Flavor Factory in Italy. Detector components are modeled as thin sections of planes, cylinders, disks or cones. Particle-material interactions are modeled using simplified cross-sections and formulas. Active detectors are modeled using parameterized response functions. Geometry and response parameters are configured using xml files with a custom-designed schema. Reconstruction algorithms adapted from BaBar are used to build tracks and clusters. Multiple sources of background signals can be merged with primary signals. Pattern recognition errors are modeled statistically by randomly misassigning nearby tracking hits. Standard BaBar analysis tuples are used as an event output. Hadronic B meson pair events can be simulated at roughly 10Hz.
38971102
CDB - Distributed Conditions Database of BaBar Experiment
This document presents CDB – Distributed Conditions Database of the BaBar Experiment [1]. CDB is the second major iteration of the database deployed in BaBar for production use as of October 2002. It replaced the original version of the database [2] used through the first three years of the data taking. The new design and its implementation are aiming at performance and scalability limitations of the original database, as well as at emerging challenges of a distributed data production and analysis system [3] of the Experiment.
61201473
GLOBAL VDET PATTERN RECOGNITION FOR ALEPH
With the current reliance on high-precision vertex detectors to provide very accurate information about the primary and secondary vertices in an event, the accuracy and ee-ciency of the assignment of vertex detector hits to tracks has become crucial. This paper discusses new software written for ALEPH which attempts to make this assignment in a global manner using integer programming techniques.
120407877
HEND: A DATABASE FOR HIGH-ENERGY NUCLEAR DATA
We propose to develop a high-energy heavy-ion experimental database and make it accessible to the scientific community through an on-line interface. The database will be searchable and cross-indexed with relevant publications, including published detector descriptions. It should eventually contain all published data from older heavy-ion programs such as the Bevalac, AGS, SPS and FNAL fixed-target programs, as well as published data from current programs at RHIC and new facilities at GSI (FAIR), KEK/Tsukuba and the LHC collider. This data includes all proton-proton, proton-nucleus to nucleus-nucleus collisions as well as other relevant systems and all measured observables. Such a database would have tremendous scientific payoff as it makes systematic studies easier and allows simpler benchmarking of theoretical models to a broad range of experiments. To enhance the utility of the database, we propose periodic data evaluations and topical reviews. These reviews would provide an alternative and impartial mechanism to resolve discrepancies between published data from rival experiments and between theory and experiment. Since this database will be a community resource, it requires the high-energy nuclear physics community's financial and manpower support.
124330538
Giant resonances observed in the scattering of 96- and 115-MeV alpha particles
Beams of 96- and 115-MeV $alpha$ particles were used to study the giant resonance region in 27 nuclei ranging from $sup 14$N to $sup 208$Pb. A prominent broad (GAMMA=3--7 MeV) peak is present in the spectra at an excitation energy of approx.63/A$sup 1$/$sup 3$ MeV for all nuclei studied with A> or =36. No such prominent peak is apparent for A<32. The angular distributions of the peak are characterized by an oscillatory behavior which is quite different from the monotonic behavior of the background. Distorted wave calculations with L=2 reproduce the experimental angular distributions quite well for most of the nuclei. Energy-weighted sum rule fractions range from 30--50% for the lighter targets to near 100% for the heavier targets. Distorted wave calculations with a breathing mode (L=0) form factor fail to reproduce the observed resonance strength by about a factor of 3 for all targets. The width of the peak is smallest for the closed shell nuclei $sup 40$Ca, $sup 90$Zr, $sup 144$Sm, and $sup 208$Pb. A small but significant broadening is observed in the rare-earth region of deformed nuclei. The giant dipole resonance is not appreciably excited for any of the targets. (AIP)