Open Charm Measurement in p+p $\sqrt{s}$ = 200 GeV Collisions at STAR

TL;DR

This paper reports the first reconstruction of open charm meson D^0 in p+p collisions at 200 GeV at RHIC, providing baseline data for understanding charm production and QCD medium effects.

Contribution

It presents the first measurement of D^0 mesons via their decay to K and π in p+p collisions at RHIC, utilizing new detector data to improve identification.

Findings

Successful reconstruction of D^0 mesons in p+p collisions

Enhanced particle identification with new Time-Of-Flight detector

Provides baseline charm production data for heavy ion studies

Abstract

The charm production is sensitive to early dynamics of the created system in RHIC heavy ion collisions. Dominant process of charm quarks production at RHIC is believed to be initial gluon fusion which can be calculated in the perturbative QCD. Understanding both the charm production total cross section and the fragmentation in p+p collisions is a baseline to further exploring the QCD medium via open charm and charmonium in heavy ion collisions. In this paper we present the first reconstruction of open charm meson $D^{0}$ via the weak decay to K and $\pi$ mesons in the p+p collisions at $\sqrt{s}$ = 200 GeV. The analysis is based on the large p+p minimum bias sample collected in RHIC year 2009 by the STAR detector. The $D^0$ decay daughter identification was improved by using the data of the newly installed Time-Of-Flight detector with 72% of its designed coverage.