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f49fc45d | 1 | // |
2 | // See implementation or Doxygen comments for more information | |
3 | // | |
4 | #ifndef ALIAODFORWARDMULT_H | |
5 | #define ALIAODFORWARDMULT_H | |
7e4038b5 | 6 | #include <TObject.h> |
7 | #include <TH2D.h> | |
8 | class TBrowser; | |
9 | /** | |
10 | * Class that contains the forward multiplicity data per event | |
11 | * | |
12 | * This class contains a histogram of | |
13 | * @f[ | |
14 | * \frac{d^2N_{ch}}{d\eta d\phi}\quad, | |
15 | * @f] | |
16 | * as well as a trigger mask for each analysed event. | |
17 | * | |
18 | * The eta acceptance of the event is stored in the underflow bins of | |
19 | * the histogram. So to build the final histogram, one needs to | |
20 | * correct for this acceptance (properly weighted by the events), and | |
21 | * the vertex efficiency. This simply boils down to defining a 2D | |
22 | * histogram and summing the event histograms in that histogram. One | |
23 | * should of course also do proper book-keeping of the accepted event. | |
24 | * | |
25 | * @code | |
fa4236ed | 26 | * TTree* GetAODTree() |
27 | * { | |
28 | * TFile* file = TFile::Open("AliAODs.root","READ"); | |
29 | * TTree* tree = static_cast<TTree*>(file->Get("aodTree")); | |
30 | * return tree; | |
31 | * } | |
32 | * | |
33 | * void Analyse() | |
34 | * { | |
35 | * TH2D* sum = 0; // Summed hist | |
36 | * TTree* tree = GetAODTree(); // AOD tree | |
37 | * AliAODForwardMult* mult = 0; // AOD object | |
38 | * Int_t nTriggered = 0; // # of triggered ev. | |
39 | * Int_t nWithVertex= 0; // # of ev. w/vertex | |
40 | * Int_t nAccepted = 0; // # of ev. used | |
41 | * Int_t nAvailable = tree->GetEntries(); // How many entries | |
42 | * Float_t vzLow = -10; // Lower ip cut | |
43 | * Float_t vzHigh = 10; // Upper ip cut | |
44 | * Int_t mask = AliAODForwardMult::kInel;// Trigger mask | |
45 | * tree->SetBranchAddress("forward", &forward); // Set the address | |
7e4038b5 | 46 | * |
47 | * for (int i = 0; i < nAvailable; i++) { | |
48 | * // Create sum histogram on first event - to match binning to input | |
49 | * if (!sum) sum = static_cast<TH2D*>(mult->Clone("d2ndetadphi")); | |
50 | * | |
51 | * tree->GetEntry(i); | |
52 | * | |
53 | * // Other trigger/event requirements could be defined | |
54 | * if (!mult->IsTriggerBits(mask)) continue; | |
55 | * nTriggered++; | |
fa4236ed | 56 | * |
57 | * // Check if we have vertex | |
58 | * if (!mult->HasIpZ()) continue; | |
59 | * nWithVertex++; | |
7e4038b5 | 60 | * |
61 | * // Select vertex range (in centimeters) | |
62 | * if (!mult->InRange(vzLow, vzHigh) continue; | |
63 | * nAccepted++; | |
64 | * | |
65 | * // Add contribution from this event | |
66 | * sum->Add(&(mult->GetHistogram())); | |
67 | * } | |
68 | * | |
69 | * // Get acceptance normalisation from underflow bins | |
70 | * TH1D* norm = sum->Projection("norm", 0, 1, ""); | |
71 | * // Project onto eta axis - _ignoring_underflow_bins_! | |
72 | * TH1D* dndeta = sum->Projection("dndeta", 1, -1, "e"); | |
73 | * // Normalize to the acceptance | |
74 | * dndeta->Divide(norm); | |
75 | * // Scale by the vertex efficiency | |
fa4236ed | 76 | * dndeta->Scale(Double_t(nWithVertex)/nTriggered, "width"); |
7e4038b5 | 77 | * // And draw the result |
78 | * dndeta->Draw(); | |
fa4236ed | 79 | * } |
7e4038b5 | 80 | * @endcode |
81 | * | |
82 | * The above code will draw the final @f$ dN_{ch}/d\eta@f$ for the | |
83 | * selected event class and vertex range | |
84 | * | |
85 | * The histogram can be used as input for other kinds of analysis too, | |
86 | * like flow, event-plane, centrality, and so on. | |
87 | * | |
7c1a1f1d | 88 | * @ingroup pwg2_forward |
7e4038b5 | 89 | */ |
90 | class AliAODForwardMult : public TObject | |
91 | { | |
92 | public: | |
93 | /** | |
94 | * Bits of the trigger pattern | |
95 | */ | |
96 | enum { | |
97 | /** In-elastic collision */ | |
98 | kInel = 0x001, | |
99 | /** In-elastic collision with at least one SPD tracklet */ | |
100 | kInelGt0 = 0x002, | |
101 | /** Non-single diffractive collision */ | |
102 | kNSD = 0x004, | |
103 | /** Empty bunch crossing */ | |
104 | kEmpty = 0x008, | |
105 | /** A-side trigger */ | |
106 | kA = 0x010, | |
107 | /** B(arrel) trigger */ | |
108 | kB = 0x020, | |
109 | /** C-side trigger */ | |
110 | kC = 0x080, | |
111 | /** Empty trigger */ | |
112 | kE = 0x100 | |
113 | }; | |
114 | /** | |
115 | * Default constructor | |
116 | * | |
117 | * Used by ROOT I/O sub-system - do not use | |
118 | */ | |
119 | AliAODForwardMult(); | |
120 | /** | |
121 | * Constructor | |
122 | * | |
f49fc45d | 123 | * @param isMC Whether this was from MC or not |
7e4038b5 | 124 | */ |
f49fc45d | 125 | AliAODForwardMult(Bool_t isMC); |
7e4038b5 | 126 | /** |
127 | * Destructor | |
128 | */ | |
f49fc45d | 129 | virtual ~AliAODForwardMult() {} // Destructor |
7e4038b5 | 130 | /** |
131 | * Initialize | |
132 | * | |
133 | * @param etaAxis Pseudo-rapidity axis | |
134 | */ | |
135 | void Init(const TAxis& etaAxis); | |
136 | /** | |
137 | * Get the @f$ d^2N_{ch}/d\eta d\phi@f$ histogram, | |
138 | * | |
139 | * @return @f$ d^2N_{ch}/d\eta d\phi@f$ histogram, | |
140 | */ | |
f49fc45d | 141 | const TH2D& GetHistogram() const { return fHist; } // Get histogram |
7e4038b5 | 142 | /** |
143 | * Get the @f$ d^2N_{ch}/d\eta d\phi@f$ histogram, | |
144 | * | |
145 | * @return @f$ d^2N_{ch}/d\eta d\phi@f$ histogram, | |
146 | */ | |
f49fc45d | 147 | TH2D& GetHistogram() { return fHist; } // Get histogram |
7e4038b5 | 148 | /** |
149 | * Get the trigger mask | |
150 | * | |
151 | * @return Trigger mask | |
152 | */ | |
f49fc45d | 153 | UInt_t GetTriggerMask() const { return fTriggers; } // Get triggers |
7e4038b5 | 154 | /** |
155 | * Set the trigger mask | |
156 | * | |
157 | * @param trg Trigger mask | |
158 | */ | |
f49fc45d | 159 | void SetTriggerMask(UInt_t trg) { fTriggers = trg; } // Set triggers |
7e4038b5 | 160 | /** |
161 | * Set bit(s) in trigger mask | |
162 | * | |
163 | * @param bits bit(s) to set | |
164 | */ | |
f49fc45d | 165 | void SetTriggerBits(UInt_t bits) { fTriggers |= bits; } // Set trigger bits |
7e4038b5 | 166 | /** |
167 | * Check if bit(s) are set in the trigger mask | |
168 | * | |
169 | * @param bits Bits to test for | |
170 | * | |
171 | * @return | |
172 | */ | |
173 | Bool_t IsTriggerBits(UInt_t bits) const; | |
174 | /** | |
175 | * Whether we have any trigger bits | |
176 | */ | |
f49fc45d | 177 | Bool_t HasTrigger() const { return fTriggers != 0; } // Check for triggers |
7e4038b5 | 178 | /** |
179 | * Clear all data | |
180 | * | |
181 | * @param option Passed on to TH2::Reset verbatim | |
182 | */ | |
183 | void Clear(Option_t* option=""); | |
184 | /** | |
185 | * browse this object | |
186 | * | |
187 | * @param b Browser | |
188 | */ | |
189 | void Browse(TBrowser* b); | |
190 | /** | |
191 | * This is a folder | |
192 | * | |
193 | * @return Always true | |
194 | */ | |
f49fc45d | 195 | Bool_t IsFolder() const { return kTRUE; } // Always true |
7e4038b5 | 196 | /** |
197 | * Print content | |
198 | * | |
199 | * @param option Passed verbatim to TH2::Print | |
200 | */ | |
201 | void Print(Option_t* option="") const; | |
202 | /** | |
203 | * Set the z coordinate of the interaction point | |
204 | * | |
205 | * @param ipZ Interaction point z coordinate | |
206 | */ | |
f49fc45d | 207 | void SetIpZ(Float_t ipZ) { fIpZ = ipZ; } // Set Ip's Z coordinate |
b2e7f2d6 | 208 | /** |
209 | * Set the center of mass energy per nucleon-pair. This is stored | |
210 | * in the (0,0) of the histogram | |
211 | * | |
212 | * @param sNN Center of mass energy per nucleon pair (GeV) | |
213 | */ | |
214 | void SetSNN(UShort_t sNN); | |
215 | /** | |
216 | * Get the collision system number | |
217 | * - 0: Unknown | |
218 | * - 1: pp | |
219 | * - 2: PbPb | |
220 | * | |
221 | * @param sys Collision system number | |
222 | */ | |
223 | void SetSystem(UShort_t sys); | |
7e4038b5 | 224 | /** |
225 | * Set the z coordinate of the interaction point | |
226 | * | |
227 | * @return Interaction point z coordinate | |
228 | */ | |
f49fc45d | 229 | Float_t GetIpZ() const { return fIpZ; } // Get Ip's Z coordinate |
7e4038b5 | 230 | /** |
231 | * Check if we have a valid z coordinate of the interaction point | |
232 | * | |
233 | * @return True if we have a valid interaction point z coordinate | |
234 | */ | |
235 | Bool_t HasIpZ() const; | |
b2e7f2d6 | 236 | /** |
237 | * Get the center of mass energy per nucleon pair (GeV) | |
238 | * | |
239 | * @return Center of mass energy per nucleon pair (GeV) | |
240 | */ | |
241 | UShort_t GetSNN() const; | |
242 | /** | |
243 | * Get the collision system number | |
244 | * - 0: Unknown | |
245 | * - 1: pp | |
246 | * - 2: PbPb | |
247 | * | |
248 | * @return Collision system number | |
249 | */ | |
250 | UShort_t GetSystem() const; | |
7e4038b5 | 251 | /** |
252 | * Check if the z coordinate of the interaction point is within the | |
253 | * given limits. Note that the convention used corresponds to the | |
254 | * convention used in ROOTs TAxis. | |
255 | * | |
256 | * @param low Lower cut (inclusive) | |
257 | * @param high Upper cut (exclusive) | |
258 | * | |
259 | * @return true if @f$ low \ge ipz < high@f$ | |
260 | */ | |
261 | Bool_t InRange(Float_t low, Float_t high) const; | |
262 | /** | |
263 | * Get the name of the object | |
264 | * | |
265 | * @return Name of object | |
266 | */ | |
f49fc45d | 267 | const Char_t* GetName() const { return (fIsMC ? "ForwardMC" : "Forward"); } |
7e4038b5 | 268 | /** |
269 | * Get a string correspondig to the trigger mask | |
270 | * | |
271 | * @param mask Trigger mask | |
272 | * | |
273 | * @return Static string (copy before use) | |
274 | */ | |
275 | static const Char_t* GetTriggerString(UInt_t mask); | |
276 | protected: | |
f49fc45d | 277 | Bool_t fIsMC; // Whether this is from MC |
7e4038b5 | 278 | TH2D fHist; // Histogram of d^2N_{ch}/(deta dphi) for this event |
279 | UInt_t fTriggers; // Trigger bit mask | |
280 | Float_t fIpZ; // Z coordinate of the interaction point | |
281 | ||
282 | static const Float_t fgkInvalidIpZ; // Invalid IpZ value | |
283 | ClassDef(AliAODForwardMult,1); // AOD forward multiplicity | |
284 | }; | |
285 | ||
286 | //____________________________________________________________________ | |
287 | inline Bool_t | |
288 | AliAODForwardMult::InRange(Float_t low, Float_t high) const | |
289 | { | |
290 | return HasIpZ() && fIpZ >= low && fIpZ < high; | |
291 | } | |
292 | ||
293 | //____________________________________________________________________ | |
294 | inline Bool_t | |
295 | AliAODForwardMult::IsTriggerBits(UInt_t bits) const | |
296 | { | |
297 | return HasTrigger() && ((fTriggers & bits) != 0); | |
298 | } | |
7e4038b5 | 299 | |
300 | #endif | |
301 | // Local Variables: | |
302 | // mode: C++ | |
303 | // End: | |
304 |