First results of the ISIS1 beam test

The in situ storage image sensor (ISIS) is a monolithic active pixel sensor with memory cells in each pixel. The memory cells are implemented as a CCD register. This and other features of the sensor make the ISIS an excellent device for detectors that will be used at the International linear collider (ILC), an electron-positron accelerator with a proposed centre-of-mass energy of around 500 GeV. The sensor can be made very thin while retaining a high signal-to-noise ratio. The memory cells can be read out between bunch trains at a relatively low clock speed, hence limiting power consumption. The actual signal charge is stored in potential wells and not on capacitors, minimizing the sensitivity to electromagnetic interference. This paper presents the results of the first beam test of the first ISIS prototype. The measurements made include the signal-to-noise ratio, position resolution and efficiency. © 2008 Elsevier B.V. All rights reserved

Results from the ISIS1 detector

The In Situ Storage Image Sensor (ISIS) is a monolithic active pixel sensor with memory cells in each pixel. The memory cells are implemented as a CCD register. A test device with parameters suitable for tracking charged particles has been constructed and characterized. The characteristics of a proof-of-principle ISIS device are described and results from using the sensor as a tracking device for high energy electrons are presented. © 2009 Elsevier B.V. All rights reserved

Search for time-dependent Bs0-Bs 0 oscillations using a vertex charge dipole technique

We report a search for Bs0-Bs0 oscillations using a sample of 400 000 hadronic Z0 decays collected by the SLD experiment. The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor. The excellent resolution provided by the pixel CCD vertex detector is exploited to cleanly reconstruct both B and cascade D decay vertices, and tag the B decay flavor from the charge difference between them. We exclude the following values of the B s0-B̄s0 oscillation frequency: Δms<4.9 ps-1 and 7.9<Δm s<10.3 ps-1 at the 95% confidence level. © 2003 The American Physical Society

Improved direct measurement of A(b) and A(c) at the Z(0) pole using a lepton tag

Contains fulltext : 128922.pdf (publisher's version ) (Open Access

Measurement of the b-quark fragmentation function in Z0 decays

We present a measurement of the b-quark inclusive fragmentation function in Z0 decays using a novel kinematic B-hadron energy reconstruction technique. The measurement was performed using 350 000 hadronic Z0 events recorded in the SLD experiment at SLAC between 1997 and 1998. The small and stable SLC beam spot and the charge-coupled-device-based vertex detector were used to reconstruct B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measured the B energy with good efficiency and resolution over the full kinematic range. We compared the scaled B-hadron energy distribution with models of b-quark fragmentation and with several ad hoc functional forms. A number of models and functions are excluded by the data. The average scaled energy of weakly decaying B hadrons was measured to be (xb) = 0.709±0.003(stat)±0.003(syst)±0.002(model)

Precise measurement of the b-quark fragmentation function in Z(0) boson decays

We have developed a new technique for inclusive reconstruction of the energy of B hadrons. The excellent efficiency and resolution of this technique allow us to make the most precise determination of the b-quark fragmentation function, using e+e-→Z0 decays recorded in the SLAC Large Detector experiment. We compared our measurement with the predictions of a number of fragmentation models. We excluded several of these models and measured the average scaled energy of weakly decaying B hadrons to be (xB) = 0.714 ± 0.005(stat) ± 0.007(syst) ± 0.002 (model dependence). © 2000 The American Physical Society