TY - JOUR
T1 - Particle identification in ALICE
T2 - a Bayesian approach
AU - Adam, J.
AU - Adamova, D.
AU - Aggarwal, MM.
AU - Rinella, G.A.
AU - Agnello, Maria
AU - Agrawal, N.
AU - Ahammed, Z.
AU - Ahmad, Shamim
AU - U. Ahn, S.
AU - Aiola, S.
AU - Bearden, Ian
AU - Bøggild, Hans
AU - Christensen, Christian Holm
AU - Gulbrandsen, Kristjan Herlache
AU - Gaardhøje, Jens Jørgen
AU - Nielsen, Børge Svane
AU - Hansen, Alexander Colliander
AU - Bilandzic, Ante
AU - Chojnacki, Marek
AU - Zaccolo, Valentina
PY - 2016/5/1
Y1 - 2016/5/1
N2 - We present a Bayesian approach to particle identification (PID) within the ALICE experiment. The aim is to more effectively combine the particle identification capabilities of its various detectors. After a brief explanation of the adopted methodology and formalism, the performance of the Bayesian PID approach for charged pions, kaons and protons in the central barrel of ALICE is studied. PID is performed via measurements of specific energy loss (dE/dx) and time of flight. PID efficiencies and misidentification probabilities are extracted and compared with Monte Carlo simulations using high-purity samples of identified particles in the decay channels K0 S→ π-π+}, ɸ → K-K+, and Λ → p π- in p-Pb collisions at √sNN=5.02 TeV. In order to thoroughly assess the validity of the Bayesian approach, this methodology was used to obtain corrected pT spectra of pions, kaons, protons, and D0 mesons in pp collisions at √s=7 TeV. In all cases, the results using Bayesian PID were found to be consistent with previous measurements performed by ALICE using a standard PID approach. For the measurement of D0 → K-π+, it was found that a Bayesian PID approach gave a higher signal-to-background ratio and a similar or larger statistical significance when compared with standard PID selections, despite a reduced identification efficiency. Finally, we present an exploratory study of the measurement of Λc + → p K-π+ in pp collisions at √s=7 TeV, using the Bayesian approach for the identification of its decay products.
AB - We present a Bayesian approach to particle identification (PID) within the ALICE experiment. The aim is to more effectively combine the particle identification capabilities of its various detectors. After a brief explanation of the adopted methodology and formalism, the performance of the Bayesian PID approach for charged pions, kaons and protons in the central barrel of ALICE is studied. PID is performed via measurements of specific energy loss (dE/dx) and time of flight. PID efficiencies and misidentification probabilities are extracted and compared with Monte Carlo simulations using high-purity samples of identified particles in the decay channels K0 S→ π-π+}, ɸ → K-K+, and Λ → p π- in p-Pb collisions at √sNN=5.02 TeV. In order to thoroughly assess the validity of the Bayesian approach, this methodology was used to obtain corrected pT spectra of pions, kaons, protons, and D0 mesons in pp collisions at √s=7 TeV. In all cases, the results using Bayesian PID were found to be consistent with previous measurements performed by ALICE using a standard PID approach. For the measurement of D0 → K-π+, it was found that a Bayesian PID approach gave a higher signal-to-background ratio and a similar or larger statistical significance when compared with standard PID selections, despite a reduced identification efficiency. Finally, we present an exploratory study of the measurement of Λc + → p K-π+ in pp collisions at √s=7 TeV, using the Bayesian approach for the identification of its decay products.
U2 - 10.1140/epjp/i2016-16168-5
DO - 10.1140/epjp/i2016-16168-5
M3 - Journal article
SN - 2190-5444
VL - 131
JO - The European Physical Journal Plus
JF - The European Physical Journal Plus
IS - 5
M1 - 168
ER -