Charmed meson measurement using a Silicon tracker in Au+Au collisions at √sNN = 200 GeV 
in STAR experiment at RHIC

Collisions of heavy ions, which are travelling close to the speed of light creates extreme 
temperatures and densities, and they might produce a new form of nuclear matter, which 
might have existed moments after the Big Bang. Understanding how nuclear matter behaves 
under these conditions might help us to know how matter behaved at the beginning of the 
Universe as well as to study exotic objects in the cosmos. The data for this analysis 
comes from the STAR experiment at Relativistic Heavy Ion Collider (RHIC) located at 
Brookhaven National Laboratory (BNL), Upton, NY.  Heavy ion collisions at RHIC, creates 
extreme temperatures and densities that the protons and neutrons inside the nuclei melt 
to form a soup of quarks, antiquarks and gluons called Quark-Gluon Plasma (QGP). Striking 
observations from RHIC, such as partonic collectivity and jet quenching have led us to the
 conclusion that strongly interacting, deconfined partonic matter (QGP) is created in Au+Au
 collisions at √sNN =200 GeV. The properties of this new matter, however are still not well
 understood, especially the production and properties of heavy quarks like charm and beauty. 
The energy loss of charm quarks shows an anomalous behavior in previous studies, which uses 
an indirect method based on decay electrons. So in this dissertation, we try a direct 
topological reconstruction of neutral charm mesons through the decay channel D0(D0bar) → K∓ π±. 
The method uses constrained fit for secondary vertex reconstruction. The new feature of this 
dataset is that the data collected included the Silicon Drift and Silicon Strip detectors; 
their pointing capabilities are crucial for this analysis. Results obtained on neutral 
D-meson measurements are presented.