Speaker
Xianbao Yuan
(University and INFN, Padova, Italy - Institute of Particle Physics, Central China Normal University)
Description
ALICE is a general-purpose heavy-ion experiment designed to study
the physics of strongly interacting matter and the quark gluon-plasma in nucleus-nucleus collisions at the LHC.
The measurement of open charm and open beauty production allows
one to investigate the mechanisms of heavy-quark production,
propagation and, at low momenta, hadronisation in the hot and dense
medium formed in high-energy nucleus-nucleus collisions.
The track impact parameter, defined as the distance of closest
approach of a track to the primary(collision or initial) vertex, is the variable allowing to evaluate the displacement of the track. It is a critical variable for the selection of physics signals which are tagged by the secondary vertex with a small displacement from the primary vertex.
This is, in particular, the case for the detection of particles with open charm and open beauty, namely D0 (cτ ∼ 123μm) , D+ (cτ ∼ 315μm) and B mesons(cτ ∼ 500μm). The main requirement applied for the selection of such particles is the presence of one or more daughter tracks (decay products) which are displaced from the primary vertex (e.g. for D0 → K− π+ two displaced tracks are required.
This poster presents the ALICE track impact parameter resolution
for the pp and Pb-Pb collisions, as well as the performance on the
exclusive reconstruction of the decay D0 → K− π+.
Author
Xianbao Yuan
(University and INFN, Padova, Italy - Institute of Particle Physics, Central China Normal University)
