The TOFp/pVPD time-of-flight system for STAR

Abstract

A time-of-flight system was constructed for the STAR Experiment for the direct identification of hadrons produced in 197 Au+ 197 Au collisions at RHIC. The system consists of two separate detector subsystems, one called the pVPD (the "start" detector) and the other called the TOFp tray (the "stop" detector). Each detector is based on conventional scintillator/phototube technology and includes custom highperformance front-end electronics and a common CAMAC-based digitization and read-out. The design of the system and its performance during the 2001 RHIC run will be described. The start resolution attained by the pVPD was 24 ps, implying a pVPD single-detector resolution of 58 ps. The total time resolution of the system averaged over all detector channels was 87 ps, allowing direct π/K/p discrimination for momenta up to ∼1.8 GeV/c, and direct (π+K)/p discrimination up to ∼3 GeV/c.

Observation ofD0Meson Nuclear Modifications inAu+AuCollisions atAdamczyk1, Adkins2, Agakishiev3 et al. 2014Phys. Rev. Lett.19466901View full textAdd to dashboardCite

“…A total of ∼8.2 × 10 8 minimum-bias-triggered (MB) events and ∼2.4 × 10 8 0%-10% most-central events are used. The MB trigger condition is defined as a coincidence signal between the east and west vertex position detectors (VPD) [17] located at 4.4 < jηj < 4.9. In this analysis, 0%-80% of the total hadronic cross section is selected, and the ∼12% VPD triggering inefficiency, mostly in the peripheral collisions, is corrected using a Monte Carlo (MC) Glauber simulation [18].…”

J/ψproduction at low transverse momentum inp+pandd+ Au collisions at

“…The MB trigger was generated from the Vertex Position Detectors (VPDs) [22] to select collisions with a vertex position |V Z | < 30 cm by requiring coincidence signals within a bunch crossing in its East (gold facing in case of d+Au collisions) and West detectors, both located 5.7 m from the center of the TPC. The collision V Z used in the trigger was evaluated from the time difference between VPD signals.…”

Event-by-event hadron ratio fluctuations from Au+Au collisions at RHIC-STAR

“…Tracks within 2σ deviation of the expected particle's Bethe-Bloch curve were identified as pions, kaons and protons. The recently completed Time of Flight (TOF) detector [8] was also used in this analysis, which greatly enhanced the ability to identify particles. By utilizing the TPC and TOF, pions and kaons were selected with transverse momentum T > 0 2 GeV/ and momentum < 1 6 GeV/ , and protons with T > 0 4 GeV/ and < 3 0 GeV/ .…”