0000000000423497
AUTHOR
M. Convery
Search for Production of Invisible Final States in Single-Photon Decays of Υ(1S)
We search for single-photon decays of the Upsilon(1S) resonance, Upsilon->gamma+invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A0, or a pair of dark matter particles, chi chi-bar. Both A0 and chi are assumed to have zero spin. We tag Upsilon(1S) decays with a dipion transition Upsilon(2S)->pi+pi-Upsilon(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m_A0<=9.2 GeV and m_chi<=4.5 GeV in the sample of 98e6 Upsilon(2S) decays collected with the BaBar detector and set stringent limits on new physics models that contain light dark ma…
THE FASTBUS READ-OUT SYSTEM FOR THE ALEPH TIME PROJECTION CHAMBER
The readout system for the Aleph central tracking detector, a large time projection chamber (TPC), consists of more than 100 FASTBUS crates with approximately 1000 FASTBUS modules. The detector and its associated electronics are briefly presented, followed by a more detailed description of the readout and control system. The discussion covers the sector readout, electronics calibration, front-end data acquisition, data pipelining, and service request handling. Experiences with the system are discussed. >
ALEPH: a Detector for Electron-Positron Annihilations at LEP
Process-centred Software Engineering Environments (PSEE) are the most recent generation of environments supporting software development activities. Most of PSEE are based on mechanisms promoting enforcement and automation of process activities. In this kind of mechanisms the process models are prescribed in a detailed and complete way. But the experience shows that supporting processes is more concerned with the flexibility of guidance offered during the process performance than with enforcement of a collection of predefined process models. In this paper, we present a solution to support strategic processes in a PSEE by providing a flexible guidance during process enactment.