125896802
Search for high-mass resonances and other exotica at the LHC
119211346
Hadron showers in a digital hadron calorimeter
A small prototype of a finely granulated digital hadron calorimeter with Resistive Plate Chambers as active elements was exposed to positive pions of 1–16 GeV energy from the Fermilab test beam. The event selection separates events with mostly non-interacting particles and events with hadronic showers which initiated in the front part of the calorimeter. The data are compared to a Monte Carlo simulation of the set-up. The paper concludes with predictions for the performance of an extended digital hadron calorimeter.
120352655
The ASTERIX spectrometer at LEAR
The ASTERIX spectrometer has been used to study the formation and the ground state of the pp atom and exclusive final states of pp annihilation at rest in a H2 gas target at NTP, using antiprotons from the Low Energy Antiproton Ring (LEAR) at CERN. The article describes the mechanical construction of the apparatus, the trigger logic, the chamber readout, and the data acquisition system. The detector calibration and the offline processing of the 55 million reconstructed events are illustrated. An overview is given about the new physics results obtained by the experiment.
173983707
Detecting High Mass H 0 A 0 Pairs at a 1 TeV Linear Collider
This note describes results from a study ofH0A0 associated production at a linear e+e− collider with √ s = 1.0 TeV. For the values of tanβ as well as the H0 and A0 masses considered here, the dominant decay mode is bb pairs. This fully hadronic final state has limited backgrounds at an e+e− collider, but at the LHC or VLHC it suffers extremely high backgrounds from standard QCD jet production. At an e+e− collider, the dominant background is tt production with fully hadronic t–quark decay in which the c–quarks fromW± decay are misidentified as b’s. Other backgrounds such as four–fermion production are negligible because of the signal is dominated by a four b final state. The results of this study are quite encouraging. Good signal–to–background was observed using event rates alone, and reconstructed Higgs mass distributions showed high–efficiency, low background regions. This note has four sections. The first is a description of the Monte Carlo generation and simulation. The second describes the analysis, including mass reconstruction and jet–flavor identification. The third presents the results, and the fourth discusses additional work to be done.
54177341
Measurement of the rate capability of Resistive Plate Chambers
This paper reports on detailed measurements of the performance of Resistive Plate Chambers in a proton beam with variable intensity. Short term effects, such as dead time, are studied using consecutive events. On larger time scales, for various beam intensities the chamber's efficiency is studied as a function of time within a spill of particles. The correlation between the efficiency of chambers placed in the same beam provides an indication of the lateral size of the observed effects. The measurements are compared to the predictions of a simple model based on the assumption that the resistive plates behave as pure resistors.
14888027
A precision synchrotron radiation detector using phosphorescent screens
A precision detector to measure synchrotron radiation beam positions is described. It has been designed and installed as part of the beam energy spectrometers at the Stanford Linear Collider (SLC). The distance between pairs of synchrotron radiation beams is measured absolutely to better than 28 mu m on a pulse-to-pulse basis. This contributes less than 5 MeV to the error in measuring SLC beam energies (approximately 50 GeV). A system of high-resolution video cameras viewing precisely aligned fiducial wire arrays overlaying phosphorescent screens has achieved this accuracy. >
116408887
The BTeV trigger and data acquisition system
The BTeV trigger inspects every beam crossing of the Fermilab Tevatron, running at a luminosity of 2 x 10{sup 32}/cm{sup 2}-s, and selects events that have ''detached vertices'' from B decays occurring downstream of the main interaction. The system uses a massively parallel system of FPGAs and microprocessors to produce a trigger decision on average every 396 ns. The trigger calculations are facilitated by the 23 Million channel pixel detector that provides the input to the trigger. Front end electronics sparsifies the remainder of event data and sends it to large, Tbyte, memory buffers that store it until the trigger decision can be made. This complex system presents special challenges in fault monitoring and power and cooling.
121921154
$B$ physics at hadron colliders
This paper discusses the physics opportunity and challenges for doing high precision B physics experiments at hadron colliders. It describes how these challenges have been addressed by the two currently operating experiments, CDF and D0, and how they are addressed by three experiments, ATLAS, CMS, and LHCb, at the LHC.
112436340
CHEP95 CONFERENCE SUMMARY
121991089
Status of BTeV: A dedicated b physics experiment at the Fermilab Tevatron Collider
BTeV is a program whose long term goal is to carry out precision studies of CP violation, mixing, and raare decays of bottom and charmed quarks in the forward direction at the Fermilab Tevatron Collider. It is planned for the new interaction region, C0, currently being constructed. We describe the technique, physics reach, and status of BTeV.
122648151
Data acquisition and analysis in extremely high data rate experiments
The goal of elementary particle physics is to unravel the properties of matter at the deepest level—that is, to answer questions such as. What are the basic constituents of matter and how do they interact with each other? The search for the answers to such questions has led us to probe the structure of matter at ever‐smaller length scales—from atomic to nuclear and now subnuclear scales. Investigating very small distance scales (below 10−13 cm) has required very high‐energy particles and, consequently, the development of gigantic particle accelerators for producing such particles. (See the box on page 55.) Although these high energy accelerators are marvels of technical and scientific ingenuity, the massive amount of data they produce could not be collected, analyzed and reduced to physics results without another marvel of modern technology: the digital computer!