The above diagram shows some of the subdetectors of STAR. The time projection chamber (TPC) is shown in red, the barrel time of flight (BTOF) is shown in yellow, and the vertex position detector (VPD) is shown along the beampipe.
When comparing our optimized start-less TOF to default start-less TOF for p+Au in the figure below, we see that the integrated yield is increased by ~2%, the RMS decreases by ~19%, and the single-hit time resolution is σBTOF ~ 75 ps compared to the default resolution of ~87 ps. Similar results are observed in p+p. Also, the dE/dx correction shifts the centroid of the plot in the figure below closer to zero, meaning the measured flight time matches what is expected for a pion of that momentum. All the improvements I made have been added to the STAR software library, and have been utilized by other researchers in the collaboration.
Measured flight times of pions selected via dE/dx with 0.8 < p < 1.0 GeV/c, measured in units of the intrinsic time resolution. The red curve shows the results using the default start-less TOF algorithm, while the blue curve shows the results obtained when analyzing exactly the same p+Au events with our optimized algorithm.