The STAR Heavy Flavor Tracker and Upgrade Plan

The Heavy Flavor Tracker (HFT) of the STAR experiment at RHIC is the first application of the state-of-the-art thin Monolithic Active Pixel Sensors (MAPS) technology in a collider environment. The HFT is composed of two silicon PiXeL detector (PXL) layers, an Intermediate Silicon Tracker (IST) and a Silicon Strip Detector (SSD). It greatly improves the impact parameter resolution of STAR tracking and enables reconstruction of secondary decay vertices of open heavy hadrons in heavy ion collisions, providing unique probes for studying the Quark-Gluon Plasma. In these proceedings we discuss the HFT hardware design, and current detector status and performance. The HFT was successfully commissioned during the 2014 RHIC run, taking data in Au+Au collisions at 200 GeV. The HFT performance during this run matches the expected performance, most significantly for track pointing resolution. Preliminary results have been obtained from 2014 Au+Au data analyses, demonstrating the capabilities of open charm hadron reconstruction with the HFT. Modifications to HFT subsystems have been made to improve its performance in the 2015 run in p+p, p+Au and p+Al collisions at sNN=200 GeV . In order to further improve such capabilities to measure bottom quark hadrons at RHIC energies, a faster heavy flavor tracker (HFT+) is needed to collect data at higher luminosity with good efficiency. The proposed HFT+ will be equipped with new generation of MAPS sensors with a much shorter integration time ( ≤40μs ) and possibly extend the current PXL detector acceptance with minimal modification to the original mechanical and air cooling infrastructure. Requirements for the upgraded HFT+ detector and expected performance are also presented in these proceedings.