Detailed Description

Estimate of reaction plane orientation using transverse momentum method of Danielewicz & Odyniec.

This global variable calculates a vector which estimates the direction of the impact parameter (and hence the orientation of the reaction plane) for each event.

If projectile (target) fragments are deflected away from the target (projectile), the vector obtained by summing all the transverse momenta of the particles produced in the projectile (target) rapidity region is parallel (antiparallel) to the impact parameter, $\vec{b}$. More generally, one constructs a vector $\vec{Q}$

\[ \vec{Q} = \sum_{k=1}^{N}w_k\vec{p}^t_k \]

from the transverse momenta $\vec{p}^t_k$ of all particles of the event with weights $w_k$ which are positive at projectile rapidities, negative at target rapidities.

The default weighting used is

\[ w_{k}=+1 \quad y_k/y_{P}>0.3\\ w_{k}=-1 \quad y_k/y_{P}<-0.3\\ w_{k}=0 \quad |y_k/y_{P}|<0.3 \]

where $y_k$ and $y_P$ are respectively the centre of mass rapidity of the particle and the projectile.

Before use, the projectile c.m. rapidity for the data must be set using SetNormalization(). Note that this quantity can be retrieved from reaction kinematics described by KV2Body (such as returned by KVDBSystem::GetKinematics() or KVDataAnalyser::GetKinematics()) like so:

KV2Body* kinema; // pointer to kinematics

kinema->GetNucleus(1)->GetFrame("cm")->Rapidity();

KV2Body

Relativistic binary kinematics calculator.

Definition: KV2Body.h:166

KV2Body::GetNucleus

KVNucleus * GetNucleus(Int_t i) const

Definition: KV2Body.cpp:456

KVParticle::GetFrame

KVParticle const * GetFrame(const Char_t *frame, Bool_t warn_and_return_null_if_unknown=kTRUE) const

Definition: KVParticle.cpp:865

After calculation, the $\vec{Q}$ vector can be retrieved using either GetQ() or GetSumObject() (method of KVVGVectorSum base class). This vector is the total transverse momentum transfer for the event, supposed to be parallel to the impact parameter of the event, $\vec{b}$.

When used in a list of variables with automatic TTree branch creation (see KVGVList::CreateBranches()), the following branches will be added to the tree by default:

/ Name | Index | Meaning / ---—|------—|---------------------------------------— / Q | 0 | Magnitude of $\vec{Q}$ / Phi | 1 | Azimuthal angle of $\vec{Q}$ / X | 2 | $x$-component of $\vec{Q}$ / Y | 3 | $y$-component of $\vec{Q}$

Author: John Frankland

Date: Fri Jun 25 12:08:14 2021

Definition at line 59 of file KVReactionPlaneEstimator.h.

#include <KVReactionPlaneEstimator.h>

Inheritance diagram for KVReactionPlaneEstimator:

[legend]

Public Member Functions
	KVReactionPlaneEstimator ()

	KVReactionPlaneEstimator (const Char_t *name)

virtual	~KVReactionPlaneEstimator ()

TVector3	GetQ () const

TVector3	GetQForParticle (const KVNucleus *n)

void	Init ()

void	SetNormalization (Double_t r)

Public Member Functions inherited from KVVGVectorSum
	KVVGVectorSum ()

	KVVGVectorSum (const Char_t *name)

virtual	~KVVGVectorSum ()

void	Calculate ()

void	Init ()

Public Member Functions inherited from KVVGObjectSum< TVector3 >
	KVVGObjectSum ()

	KVVGObjectSum (const Char_t *nom)

virtual	~KVVGObjectSum ()

void	Copy (TObject &obj) const

Int_t	GetMult () const

const TVector3 &	GetSumObject () const

void	Reset ()

Public Member Functions inherited from KVVarGlob
	KVVarGlob ()

	KVVarGlob (const Char_t *nom)

virtual	~KVVarGlob (void)

void	AddSelection (const KVParticleCondition &sel)

Double_t	AsDouble () const

void	DefineNewFrame (KVEvent *e) const

void	Fill (const KVNucleus *c)

void	Fill2 (const KVNucleus n1, const KVNucleus n2)

virtual void	FillN (const KVEvent *)

const TString &	GetFrame () const

Int_t	GetNameIndex (const Char_t *name) const

Double_t	GetNormalization () const

Int_t	GetNumberOfBranches () const

virtual Int_t	GetNumberOfValues () const

TString	GetOptionString (const Char_t *opt) const

Double_t	GetParameter (const Char_t *par) const

Double_t	GetValue (const Char_t *name) const

Double_t	GetValue (Int_t i) const

Double_t	GetValue (void) const

virtual TString	GetValueName (Int_t i) const

const KVNameValueList &	GetValueNameList () const

virtual Char_t	GetValueType (Int_t) const

virtual std::vector< Double_t >	GetValueVector (void) const

Bool_t	HasValue (const Char_t *name) const

bool	IsDefiningNewFrame () const

virtual Bool_t	IsGlobalVariable () const

Bool_t	IsNBody () const

Bool_t	IsOneBody () const

Bool_t	IsOptionGiven (const Char_t *opt)

Bool_t	IsParameterSet (const Char_t *par)

bool	IsSelectingEvents () const

Bool_t	IsTwoBody () const

void	ListInit ()

	operator double () const

Double_t	operator() (const Char_t *name) const

Double_t	operator() (Int_t i) const

Double_t	operator() (void) const

void	Print (Option_t *="") const

void	SetDefineGroup (const KVString &groupname="")

void	SetEventSelection (const EventSelector &f)

void	SetFrame (const Char_t *ref)

void	SetMaxNumBranches (Int_t n)

void	SetNewFrameDefinition (const FrameSetter &f)

void	SetOption (const Char_t option, const Char_t value)

void	SetParameter (const Char_t *par, Double_t value)

void	SetSelection (const KVParticleCondition &sel)

bool	TestEventSelection () const

void	UnsetOption (const Char_t *opt)

void	UnsetParameter (const Char_t *par)

Public Member Functions inherited from KVBase
	KVBase ()
	Default constructor. More...

	KVBase (const Char_t name, const Char_t title="")
	Ctor for object with given name and type. More...

	KVBase (const KVBase &)
	copy ctor More...

virtual	~ KVBase ()

virtual void	Clear (Option_t *opt="")
	Clear object properties : name, type/title, number, label. More...

const Char_t *	GetLabel () const

UInt_t	GetNumber () const

UInt_t	GetNumberOfObjects () const

virtual TObject *	GetObject () const

virtual const Char_t *	GetType () const

Bool_t	HasLabel () const

virtual Bool_t	IsCalled (const Char_t *name) const

Bool_t	IsLabelled (const Char_t *l) const

virtual Bool_t	IsType (const Char_t *typ) const

virtual void	List ()

KVBase &	operator= (const KVBase &)
	copy assignment operator More...

Double_t	ProtectedGetX (const TF1 *func, Double_t val, int &status, Double_t xmin=0.0, Double_t xmax=0.0) const

void	SetLabel (const Char_t *lab)

virtual void	SetNumber (UInt_t num)

virtual void	SetType (const Char_t *str)

Static Public Member Functions
static TF1 *	GetDeltaPhiRFitFunction ()

Static Public Member Functions inherited from KVVarGlob
static void	MakeClass (const Char_t classname, const Char_t classdesc, int type=kOneBody)

Static Public Member Functions inherited from KVBase
static Bool_t	AreEqual (Double_t x, Double_t y, Long64_t maxdif=1)
	Comparison between two 64-bit floating-point values. More...

static void	BackupFileWithDate (const Char_t *path)

static void	CombineFiles (const Char_t file1, const Char_t file2, const Char_t *newfilename, Bool_t keep=kTRUE)

static void	Deprecated (const char method, const char advice)

static Bool_t	FindClassSourceFiles (const Char_t class_name, KVString &imp_file, KVString &dec_file, const Char_t dir_name=".")

static Bool_t	FindExecutable (TString &exec, const Char_t *path="$(PATH)")

static const Char_t *	FindFile (const Char_t *search, TString &wfil)

static const Char_t *	GetBINDIRFilePath (const Char_t *namefile="")

static const Char_t *	GetDATABASEFilePath ()

static const Char_t *	GetDATADIRFilePath (const Char_t *namefile="")

static Bool_t	GetDataSetEnv (const Char_t dataset, const Char_t type, Bool_t defval)

static const Char_t *	GetDataSetEnv (const Char_t dataset, const Char_t type, const Char_t *defval)

static Double_t	GetDataSetEnv (const Char_t dataset, const Char_t type, Double_t defval)

static const Char_t *	GetETCDIRFilePath (const Char_t *namefile="")

static const Char_t *	GetExampleFilePath (const Char_t library, const Char_t namefile)
	Return full path to example file for given library (="KVMultiDet", "BackTrack", etc.) More...

static const Char_t *	GetINCDIRFilePath (const Char_t *namefile="")

static const Char_t *	GetKVBuildDate ()
	Returns KaliVeda build date. More...

static const Char_t *	GetKVBuildDir ()
	Returns top-level directory used for build. More...

static const Char_t *	GetKVBuildTime ()
	Returns KaliVeda build time. More...

static const Char_t *	GetKVBuildType ()
	Returns KaliVeda build type (cmake build: Release, Debug, RelWithDebInfo, ...) More...

static const Char_t *	GetKVBuildUser ()
	Returns username of person who performed build. More...

static const Char_t *	GetKVSourceDir ()
	Returns top-level directory of source tree used for build. More...

static const Char_t *	GetKVVersion ()
	Returns KaliVeda version string. More...

static const Char_t *	GetLIBDIRFilePath (const Char_t *namefile="")

static const Char_t *	GetListOfPlugins (const Char_t *base)

static const Char_t *	GetListOfPluginURIs (const Char_t *base)

static const Char_t *	GetPluginURI (const Char_t base, const Char_t plugin)

static void	GetTempFileName (TString &base)

static const Char_t *	GetTEMPLATEDIRFilePath (const Char_t *namefile="")

static const Char_t *	GetWORKDIRFilePath (const Char_t *namefile="")

static const Char_t *	gitBranch ()
	Returns git branch of sources. More...

static const Char_t *	gitCommit ()
	Returns last git commit of sources. More...

static void	InitEnvironment ()

static bool	is_gnuinstall ()

static Bool_t	IsThisAPlugin (const TString &uri, TString &base)

static TPluginHandler *	LoadPlugin (const Char_t base, const Char_t uri="0")

static Bool_t	OpenContextMenu (const char method, TObject obj, const char *alt_method_name="")

static void	OpenTempFile (TString &base, std::ofstream &fp)

static void	PrintSplashScreen ()
	Prints welcome message and infos on version etc. More...

static Bool_t	SearchAndOpenKVFile (const Char_t name, KVSQLite::database &dbfile, const Char_t kvsubdir="")

static Bool_t	SearchAndOpenKVFile (const Char_t name, std::ifstream &file, const Char_t kvsubdir="", KVLockfile *locks=0)

static Bool_t	SearchAndOpenKVFile (const Char_t name, std::ofstream &file, const Char_t kvsubdir="", KVLockfile *locks=0)

static Bool_t	SearchKVFile (const Char_t name, TString &fullpath, const Char_t kvsubdir="")

static const Char_t *	WorkingDirectory ()

Private Member Functions
void	fill (const KVNucleus *n)

Double_t	getvalue_int (Int_t) const

void	init ()

Private Attributes
double	fProjCMRapidity {0}

std::function< double(const KVNucleus *)>	weight_function

Additional Inherited Members
Public Types inherited from KVVarGlob
enum	{ kOneBody , kTwoBody , kNBody }

Public Types inherited from KVBase
enum	EKaliVedaBits { kIsKaliVedaObject = BIT(23) }

Constructor & Destructor Documentation

◆ KVReactionPlaneEstimator() [1/2]

KVReactionPlaneEstimator::KVReactionPlaneEstimator ( )

inline

Definition at line 79 of file KVReactionPlaneEstimator.h.

◆ KVReactionPlaneEstimator() [2/2]

KVReactionPlaneEstimator::KVReactionPlaneEstimator ( const Char_t * name )

inline

Definition at line 83 of file KVReactionPlaneEstimator.h.

◆ ~KVReactionPlaneEstimator()

virtual KVReactionPlaneEstimator::~KVReactionPlaneEstimator ( )

inlinevirtual

Definition at line 88 of file KVReactionPlaneEstimator.h.

Member Function Documentation

◆ fill()

void KVReactionPlaneEstimator::fill ( const KVNucleus * n )

inlineprivatevirtual

Reimplemented from KVVarGlob.

Definition at line 74 of file KVReactionPlaneEstimator.h.

◆ GetDeltaPhiRFitFunction()

TF1 * KVReactionPlaneEstimator::GetDeltaPhiRFitFunction ( )

static

Creates and returns a TF1 corresponding to Eqn.(12) of Ollitrault, "Reconstructing azimuthal distributions in nucleus-nucleus collisions", nucl-ex/9711003.

Use to fit distribution of $\Delta\phi_R$, the difference in azimuthal angle between the reaction planes determined for two random subevents containing half of all particles in the event, in order to determine the $\chi$ parameter which can be used to correct azimuthal distributions for the uncertainty in the determination of the reaction plane.

Parameters:

Index	Meaning
0	$\chi$
1	Normalisation

Definition at line 163 of file KVReactionPlaneEstimator.cpp.

◆ GetQ()

TVector3 KVReactionPlaneEstimator::GetQ ( ) const

inline

Returns: the total transverse momentum transfer, $\vec{Q}$

Definition at line 95 of file KVReactionPlaneEstimator.h.

◆ GetQForParticle()

TVector3 KVReactionPlaneEstimator::GetQForParticle ( const KVNucleus * n )

Returns: $\vec{Q}$ to use with particle

To avoid autocorrelation, the particle is not used in the determination of $\vec{Q}$, i.e. this is the "one plane per particle" approach.

Definition at line 87 of file KVReactionPlaneEstimator.cpp.

◆ getvalue_int()

Double_t KVReactionPlaneEstimator::getvalue_int ( Int_t i ) const

privatevirtual

Returns: the following values according to the given index:

Name	Index	Meaning
Q	0	Magnitude of $\vec{Q}$
Phi	1	Azimuthal angle of $\vec{Q}$
X	2	$x$-component of $\vec{Q}$
Y	3	$y$-component of $\vec{Q}$

Implements KVVarGlob.

Definition at line 53 of file KVReactionPlaneEstimator.cpp.

◆ init()

void KVReactionPlaneEstimator::init ( void )

private

Default initialization.

Default frame for all calculations is "CM".

Define the following values which can be retrieved with GetValue():

Name	Index	Meaning
Q	0	Magnitude of $\vec{Q}$
Phi	1	Azimuthal angle of $\vec{Q}$
X	2	$x$-component of $\vec{Q}$
Y	3	$y$-component of $\vec{Q}$

Definition at line 18 of file KVReactionPlaneEstimator.cpp.

◆ Init()

void KVReactionPlaneEstimator::Init ( void )

inlinevirtual

Make sure that projectile CM rapidity has been set before use

Implements KVVarGlob.

Definition at line 103 of file KVReactionPlaneEstimator.h.

◆ SetNormalization()

void KVReactionPlaneEstimator::SetNormalization ( Double_t r )

inlinevirtual

Use to set value of projectile CM rapidity for normalization of particle rapidities

Reimplemented from KVVarGlob.

Definition at line 90 of file KVReactionPlaneEstimator.h.

Member Data Documentation

◆ fProjCMRapidity

double KVReactionPlaneEstimator::fProjCMRapidity {0}

private

Definition at line 60 of file KVReactionPlaneEstimator.h.

◆ weight_function

std::function<double(const KVNucleus*)> KVReactionPlaneEstimator::weight_function

private

Initial value:

= [&](const KVNucleus* n)
   {
   
      auto rapidity = n->Rapidity() / fProjCMRapidity;
      if (rapidity > 0.3) return 1.0;
      else if (rapidity < -0.3) return -1.0;
      return 0.0;
   }

Definition at line 64 of file KVReactionPlaneEstimator.h.

Name	Index	Meaning
Q	0	Magnitude of \(\vec{Q}\)
Phi	1	Azimuthal angle of \(\vec{Q}\)
X	2	\(x\)-component of \(\vec{Q}\)
Y	3	\(y\)-component of \(\vec{Q}\)

Detailed Description

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ KVReactionPlaneEstimator() [1/2]

◆ KVReactionPlaneEstimator() [2/2]

◆ ~KVReactionPlaneEstimator()

Member Function Documentation

◆ fill()

◆ GetDeltaPhiRFitFunction()

◆ GetQ()

◆ GetQForParticle()

◆ getvalue_int()

◆ init()

◆ Init()

◆ SetNormalization()

Member Data Documentation

◆ fProjCMRapidity

◆ weight_function