118032706
Excited charmed mesons
The experimental status of excited charmed mesons is reviewed and is compared to theoretical expectations. Six states have been observed and their properties are consistent with those predicted for excited charmed states with orbital angular momentum equal to one.
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!
123546567
B physics, BTeV, and all that
The status of ''flavor physics'' in our pursuit of knowledge in elementary particle physics is discussed. Then, the BTeV experiment, planned for the Fermilab Tevatron collider, is described briefly and its physics reach is discussed. Comparisons are made to the current B physics experiments at e{sup +}e{sup -} facilities and to the LHCb experiment, planned for the Large Hadron Collider at CERN.
119875628
Conference summary: 6th International conference on hyperons, charm, and beauty hadrons (BEACH04)
The 6th International Conference on Hyperons, Charm, and Beauty Hadrons (BEACH04) treated us to a wonderful array of new results. Here the author attempts to summarize the talks and discuss the conference highlights.
124383108
B Physics at the Tevatron: Now, Soon, and Later
We discuss recent B physics results obtained at the Fermilab Tevatron by CDF, prospects for observing CP violation in the next run, and a proposal for a Dedicated B Collider Experiment, BTeV, at the Tevatron after the next collider run.
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.
124045765
Standard Model Physics at TeV2000
tev_2000 describes the collider physics program at the Fermilab Teva- tron for the next decade.
118570823
Status of Design, Development and Test of the Dipole Magnets for the High Energy Booster
Westinghouse Magnet Systems Division has a contract to design, develop, build and test the superconducting dipole magnets for the High Energy Booster. This paper covers the key requirements of the magnet and the design features to meet these requirements. Although similar to the Collider dipole magnets, there are some key differences in the functional requirements and design constraints which lead to design differences. Most significant is the requirement to prevent quench during bipolar operation at a ramp rate of 62 A/s compared to unipolar operation at 4 A/s for the Collider. Testing of 50 mm magnets made for the SSCL string test show that the design is sensitive to interstrand eddy currents and resultant heating at the higher ramp rate. The cryostat diameter is not constrained by the fixed distance between top and bottom rings as in the Collider. We are taking advantage of the additional space allowed. Emphasis in this paper is placed on the design differences and the reasons for them in both the cold mass and the cryostat. Our cold testing requirements and plans for test facilities to carry out the tests are summarized.
113428998
Progress in Understanding RAMP Rate Sensitivity in High Energy Booster Dipole Magnets
Quench current on some string test magnets decreased significantly with increased ramp rate. As subcontractor for the design and development of the HDMs, Westinghouse is responsible for ensuring that HDMs reach full field during the bipolar operating cycle which ramps at 62 A/s, compared with only 4 A/s for CDMs. Our objective is to specify and control design and processes to consistently produce magnets that meet ramp rate requirements. Understanding observed ramp sensitivity is necessary, along with aggressive testing of candidate design and process improvements.
118611463
Measurement of Positron Showers with a Digital Hadron Calorimeter
A small prototype of a finely granulated digital hadron calorimeter with Resistive Plate Chambers as active elements was exposed to positrons of 1?16 GeV energy from the Fermilab test beam. The response function, energy resolution, as well as measurements of the shape of electromagnetic showers are presented. The data are compared to a Monte Carlo simulation of the set-up.
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.