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1// $Id$
2
3/*!
4
5\page README_evaluation MUON Evaluation
6
7
8\section evaluation_s1 How to process invariant mass spectra for J/psi or Upsilon
9
10The macro MUONmassPlot_ESD.C reads back the MUON ESD informations and compute
11the invariant mass spectra and corresponding uncorelated background.
12Moreover gives the number of event in the resonance peak and the number of triggers.
13<pre>
14Usage:
15root [0] .L $ALICE_ROOT/MUON/MUONmassPlot_ESD.C+
16root [1] MUONmassPlot_ESD(ExtrapToVertex,
17 geoFilenam, filename
18 FirstEvent, LastEvent,
19 esdFileName,
20 ResType, Chi2Cut,
21 PtCutMin, PtCutMax,
22 massMin, massMax)
23
24with:
25ExtrapToVertex (default -1)
26 <0: no extrapolation;
27 =0: extrapolation to (0,0,0);
28 >0: extrapolation to ESDVertex if available, else to (0,0,0)
29geoFilename (default "geometry.root") geometry file name needed to extrap to vertex
30filename (default "galice.root") galice root file name
31FirstEvent (default 0)
32LastEvent (default 10000)
33esdFileName (default "AliESDs.root") esd root file name
34ResType (default 553): 553 for Upsilon, anything else for J/Psi
35Chi2Cut (default 100): keep only tracks with chi2 per d.o.f. < Chi2Cut
36PtCutMin (default 1): keep only tracks with transverse momentum > PtCutMin
37PtCutMax (default 10000): keep only tracks with transverse momentum < PtCutMax
38massMin (default 9.17 for Upsilon) keep only invariant masses with
39massMax (default 9.77 for Upsilon) massMin < mass < massMax
40</pre>
41
42\section evaluation_s2 How to run MUONRecoCheck macro
43
44To check the muon reconstruction by comparing the reconstructed tracks
45with the reference tracks made of "AliTrackReference" for the hits in chamber (0..9)
46and kinematic informations (TreeK) for the vertex.
47This macro can be used to check the track reconstruction e.g. efficiency,
48momentum resolution ... but also to make physics analysis whenever
49track identification is needed.
50
51To compile MUONRecoCheck.C
52<pre>
53.includepath $ALICE_ROOT/STEER
54.includepath $ALICE_ROOT/MUON
55.L $ALICE_ROOT/MUON/MUONRecoCheck.C+
56</pre>
57
58To run MUONRecoCheck
59<pre>
60MUONRecoCheck(nEvent,"geometry.root", "galice.root"); // nEvent = nb of events
61</pre>
62
63
64\section evaluation_s3 Macros for MC studies
65
66For MC studies the classes AliMUONTrackLight and AliMUONPairLight can be
67used in order to fill not only the single muon / dimuon's kinematics (charge,
68pT, rapidity, etc) at the generation AND reconstruction level, but also for
69"decoding" the Pythia output and for the storing of the single muon's history.
70This allows to tag if two muons of a given event come from a certain, well-defined
71process, such as J/psi, Upsilons, correlated open charm or open beauty or the
72low masses or if they are of uncorrelated origin. For open beauty/charm it also
73tags the creation process (pair creation, flavour excitation or gluon splitting).
74The classes also allow to tag feed-down or neutral B meson oscillation and
75has a method that checks whether the reconstructed track is a muon or not.
76
77The macros ReadRecoCocktail.C, DecodeRecoCocktail.C and MergeMuonLight.C
78are examples how to use these two classes. DecodeRecoCocktail.C opens the
79generated files, loops over the events and fills an AliMUONTrackLight object
80for every reconstructed track for which the reference to its generated particle
81could be established, using the AliMUONRecoCheck class.
82It then takes the AliMUONTrackLight objects and forms - event by event -
83AliMUONPairLight objects, on a combinatorial basis. For a given event these
84objects are stored in respective TClonesArrays which are then stored in a tree.
85By default, the produced output file is called "MuonLight.root".
86This root file can then be taken by the macro "ReadRecoCocktail.C" that shows,
87on the example of the reconstructed mass and pT of the AliMUONPairLight object,
88how to access the available information. For large statistics, in which many
89individual MuonLight.root files are produced, MergeMuonLight.C can be used
90to merge the files and produce one common output root file.
91
92To read a generation/reconstrution from PDC06 preproduction, and write a file
93with a tree of AliMUONTrackLight / AliMUONPairLight :
94go to the directory containing the generation/reconstruction. From there run
95aliroot
96
97<pre>
98.L DecodeRecoCocktail.C+
99DecodeRecoCocktail();
100.q
101</pre>
102
103To read the file previously generated:
104<pre>
105aliroot
106.L ReadRecoCocktail.C+
107ReadRecoCocktail();
108.q
109</pre>
110
111This chapter is defined in the READMEevaluation.txt file.
112
113*/