The BB detector: Upgrades, operation and performance Martinelli, M.; Zhu, Y.S.; Gill, M.S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2013, Letnik:
729, Številka:
C
Journal Article
This paper describes the design, construction, and initial operation of SLD's upgraded vertex detector which comprises 96 two-dimensional charge-coupled devices (CCDs) with a total of 307 Mpixel. ...Each pixel functions as an independent particle detecting element, providing space point measurements of charged particle tracks with a typical precision of 4 μm in each co-ordinate. The CCDs are arranged in three concentric cylinders just outside the beam-pipe which surrounds the e
+e
− collision point of the SLAC Linear Collider (SLC). The detector is a powerful tool for distinguishing displaced vertex tracks, produced by decay in flight of heavy flavour hadrons or tau leptons, from tracks produced at the primary event vertex. The requirements for this detector include a very low mass structure (to minimize multiple scattering) both for mechanical support and to provide signal paths for the CCDs; operation at low temperature with a high degree of mechanical stability; and high speed CCD readout, signal processing, and data sparsification. The lessons learned in achieving these goals should be useful for the construction of large arrays of CCDs or active pixel devices in the future in a number of areas of science and technology.
We present the first direct measurement of A(s), the parity-violating coupling of the Z0 boson to the strange quark, using approximately 550 000 e(+)e(-)-->Z0-->hadrons events recorded by the SLC ...Large Detector with a polarized e(-) beam. We tagged Z0-->s events by the absence of B or D hadrons and the presence in each hemisphere of a high momentum K+/- or K(0)(s). Fitting the polar angle distributions of the strangeness-signed thrust axis gave A(s) = 0.895+/-0.066(stat)+/-0.062(syst). The analyzing power and uu+d background were constrained using the data, greatly reducing any model dependence.
Initial impact parameter resolution of the new SLD vertex detector Sinev, N.B; Brau, J.E; Abe, K ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1998, Letnik:
409, Številka:
1-3
Journal Article
Recenzirano
Odprti dostop
During 1996 the SLD collaboration completed the construction of, and began the operation of, a new vertex detector (VXD3). This detector, based on 96 CCD’s each of 13cm2 area, is an upgrade of the ...original vertex detector of SLD (VXD2), and is made possible by advances in the technology of CCD detectors. New front-end electronics and a new data acquisition system were developed for this upgrade. Its improved characteristics will enhance many SLD measurements, and open the possibility to observe Bs0-mixing. More than 50000 Z events obtained with the new vertex detector have been analyzed. Results on the new detector performance (including resolution evaluation) from this first data are presented.
The parity violation parameters A(b) and A(c) of the Zb(b) and Zc(c) couplings have been measured directly, using the polar angle dependence of the polarized cross sections at the Z(0) pole. Bottom ...and charmed hadrons were tagged via their semileptonic decays. Both the electron and muon analyses take advantage of new multivariate techniques to increase the analyzing power. Based on the 1993-1998 SLD sample of 550,000 Z(0) decays produced with highly polarized electron beams, we measure A(b) = 0.919+/-0.030(stat)+/-0.024(syst), and A(c) = 0.583+/-0.055(stat)+/-0.055(syst).
We have made the first measurement of the double-inclusive B/B energy distribution in e+e− annihilations, using a sample of 400000 hadronic Z0-decay events recorded in the SLD experiment at SLAC ...between 1996 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector were used to reconstruct B/B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used to calculate the B energies in this novel technique. We measured the B/B energies with good efficiency and resolution over the full kinematic range. We measured moments of the scaled energies of the B and B hadrons vs. the opening angle between them. By comparing these results with perturbative QCD predictions we tested the ansatz of factorisation in heavy-quark production. A recent next-to-leading order calculation reproduces the data.
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