Optical alignment system for the PHENIX muon tracking chambers Murata, J; Al-Jamel, A; Armendariz, R.L ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2003, Letnik:
500, Številka:
1
Journal Article
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A micron-precision optical alignment system (OASys) for the PHENIX muon tracking chambers is developed. To ensure the required mass resolution of vector meson detection, the relative alignment ...between three tracking station chambers must be monitored with a precision of
25
μm
. The OASys is a straightness monitoring system comprised of a light source, lens and CCD camera, used for determining the initial placement as well as for monitoring the time dependent movement of the chambers on a micron scale.
The invariant differential cross section for inclusive electron production in \(p + p\) collisions at \(\sqrt{s} = 200\)~GeV has been measured by the PHENIX experiment at the Relativistic Heavy Ion ...Collider over the transverse momentum range \(0.4 \le p_T \le 5.0\)~GeV/\(c\) in the central rapidity region (\(|\eta| \le 0.35\)). The contribution to the inclusive electron spectrum from semileptonic decays of hadrons carrying heavy flavor, {\it i.e.} charm quarks or, at high \(p_T\), bottom quarks, is determined via three independent methods. The resulting electron spectrum from heavy flavor decays is compared to recent leading and next-to-leading order perturbative QCD calculations. The total cross section of charm quark-antiquark pair production is determined to be \(\sigma_{c\bar{c}} = 0.92 \pm 0.15 {\rm (stat.)} \pm 0.54 {\rm (sys.)}\)~mb.
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