Particle identification in ALICE: a Bayesian approach
J. Adam
,
Laurent Aphecetche
(1)
,
B. Audurier
(1)
,
A. Baldisseri
(2)
,
Guillaume Batigne
(1)
,
I. Belikov
(3)
,
H. Borel
(2)
,
J. Castillo Castellanos
(2)
,
J.L. Charvet
(2)
,
C. Cheshkov
(4)
,
B. Cheynis
(4)
,
L. Ducroux
(4)
,
B. Erazmus
(1)
,
Magali Estienne
(1)
,
V.J.G. Feuillard
(2)
,
Marie Germain
(1)
,
J.C. Hamon
(3)
,
B. Hippolyte
(3)
,
C. Kuhn
(3)
,
A. Lardeux
(1)
,
J. Martin Blanco
(1)
,
Gines Martinez Garcia
(1)
,
L. Molnar
(1)
,
A. Morreale
(1)
,
H. Pereira Da Costa
(2)
,
Philippe Pillot
(1)
,
A. Rakotozafindrabe
(2)
,
F. Rami
(3)
,
L. Ronflette
(1)
,
C. Roy
(3)
,
Y. Schutz
(1)
,
Alexandre Shabetai
(1)
,
Diego Stocco
(1)
,
B. Teyssier
(4)
,
R. Tieulent
(4)
,
A. Uras
(4)
,
R. Vernet
(5)
,
M. Wang
(1)
,
J. Zhu
(1)
,
G. Conesa Balbastre
(6)
,
J. Faivre
(6)
,
C. Furget
(6)
,
R. Guernane
(6)
,
C. Silvestre
(6)
,
A. Vauthier
(6)
,
Z. Conesa Del Valle
(7)
,
I. Das
(7)
,
B. Espagnon
(7)
,
C. Hadjidakis
(7)
,
I. Lakomov
(7)
,
C. Suire
(7)
,
J. D. Tapia Takaki
(7)
,
M. Tarhini
(7)
,
L. Valencia Palomo
(7)
1
SUBATECH -
Laboratoire SUBATECH Nantes
2 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
3 IPHC - Institut Pluridisciplinaire Hubert Curien
4 IPNL - Institut de Physique Nucléaire de Lyon
5 CC-IN2P3 - Centre de Calcul de l'IN2P3
6 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
7 IPNO - Institut de Physique Nucléaire d'Orsay
2 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
3 IPHC - Institut Pluridisciplinaire Hubert Curien
4 IPNL - Institut de Physique Nucléaire de Lyon
5 CC-IN2P3 - Centre de Calcul de l'IN2P3
6 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
7 IPNO - Institut de Physique Nucléaire d'Orsay
J. Adam
- Fonction : Auteur
- PersonId : 9493
- IdHAL : jean-luc-adam
- ORCID : 0000-0002-1242-6776
- IdRef : 050643592
Laurent Aphecetche
- Fonction : Auteur
- PersonId : 2010
- IdHAL : laurent-aphecetche
- ORCID : 0000-0001-7662-3878
- IdRef : 113847653
Guillaume Batigne
- Fonction : Auteur
- PersonId : 175820
- IdHAL : guillaume-batigne
- ORCID : 0000-0001-8638-6300
- IdRef : 077207874
B. Cheynis
- Fonction : Auteur
- PersonId : 750577
- IdHAL : brigitte-cheynis
- IdRef : 032215606
Magali Estienne
- Fonction : Auteur
- PersonId : 179790
- IdHAL : magali-estienne
- ORCID : 0000-0003-0687-5580
Marie Germain
- Fonction : Auteur
- PersonId : 170960
- IdHAL : marie-germain
- ORCID : 0000-0001-7382-1609
- IdRef : 176579958
Gines Martinez Garcia
- Fonction : Auteur
- PersonId : 169952
- IdHAL : gines-martinez
- ORCID : 0000-0002-8657-6742
- IdRef : 068952961
Philippe Pillot
- Fonction : Auteur
- PersonId : 175815
- IdHAL : ppillot
- ORCID : 0000-0002-9067-0803
C. Roy
- Fonction : Auteur
- PersonId : 742351
- IdHAL : christelle-roy
- ORCID : 0000-0001-5920-6271
Alexandre Shabetai
- Fonction : Auteur
- PersonId : 181202
- IdHAL : alexandre-shabetai
- ORCID : 0000-0003-3069-726X
Diego Stocco
- Fonction : Auteur
- PersonId : 170966
- IdHAL : diego-stocco
- ORCID : 0000-0002-5377-5163
- IdRef : 204479150
G. Conesa Balbastre
- Fonction : Auteur
- PersonId : 737477
- IdHAL : conesa-balbastre-gustavo
- ORCID : 0000-0001-5283-3520
Résumé
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 ($\mathrm{d}E/\mathrm{d}x$) 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 ${\rm K}^0_S \rightarrow \pi^-\pi^+$, $\phi \rightarrow {\rm K}^-{\rm K}^+$, and $\Lambda \rightarrow {\rm p}\pi^-$ in p-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV. In order to thoroughly assess the validity of the Bayesian approach, this methodology was used to obtain corrected $p_{\rm T}$ spectra of pions, kaons, protons, and D$^0$ mesons in pp collisions at $\sqrt{s}=7$ 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 D$^0 \rightarrow {\rm K}^-\pi^+$, 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 $\Lambda_{\rm c}^{+}\rightarrow {\rm p} {\rm K}^-\pi^+$ in pp collisions at $\sqrt{s}=7$ TeV, using the Bayesian approach for the identification of its decay products.