StEEmcPointUtils Class Reference

Inheritance diagram for StEEmcPointUtils:

Public Member Functions
Bool_t	opening_angle_cut (StEEmcPoint &p1, StEEmcPoint &p2, Float_t energy, Float_t mass=0.135, Float_t frac=0.3)
StEEmcPointVec_t	find_best_points (StEEmcPointVec_t points, Float_t em_energy, Bool_t &stat, Float_t &chi2, Int_t npoint=1)
Bool_t	no_parallel_smd_clusters (StEEmcPointVec_t points, Int_t npoint)

Detailed Description

Definition at line 9 of file StEEmcPointUtils.h.

Member Function Documentation

StEEmcPointVec_t StEEmcPointUtils::find_best_points	(	StEEmcPointVec_t	points,
		Float_t	em_energy,
		Bool_t &	stat,
		Float_t &	chi2,
		Int_t	npoint = 1
	)

Given a vector of points matching some energy in the endcap, return the best set of points using the following criteria:

1) assume an SMD sampling fraction of 0.6% 2) predict energy deposit in SMD 3) compute a "chi^2" = ( epredict - epoint )^2 + 4.0 ( esmdu - esmdv )^2

The set of npoints which minimizes this "chi^2" will be returned

NOTE– points which lie along the same strips will not be considered. it will be possible that no set of points will find an optimal minimum. If so, stat returns false.

Parameters

points	Input vector of points
em_energy	Electormagnetic energy we're fitting to
stat	false if it fails to find a good set of points
chi2	the "chi2" of the minimization
npoints	the number of points we're looking for.

Check sanity. Number of requested points must be no bigger than our vector.

Loop over all permutations. Calculate chi2 for the firsn npoint points.

require all smd clusters in permutation to be on different smd strips

Definition at line 18 of file StEEmcPointUtils.cxx.

References no_parallel_smd_clusters().

Bool_t StEEmcPointUtils::no_parallel_smd_clusters	(	StEEmcPointVec_t	points,
		Int_t	npoint
	)

Test if the first npoint points in the vector have SMD strips which are along the same strips (means are equal)

no clusters found along parallel strips

Definition at line 61 of file StEEmcPointUtils.cxx.

Referenced by find_best_points().

Bool_t StEEmcPointUtils::opening_angle_cut	(	StEEmcPoint &	p1,
		StEEmcPoint &	p2,
		Float_t	energy,
		Float_t	mass = 0.135,
		Float_t	frac = 0.3
	)

Returns true if the two points are outside a given fraction of the minimum opening angle for a meson with a given mass. Default is set for 30% of the pi0 minimum opening angle at a given energy.

Parameters

p1	point 1
p2	point 2
energy	energy of candidate
mass	mass of meson
frac	fraction of opening angle to test (default=0.3).

Definition at line 10 of file StEEmcPointUtils.cxx.

References StEEmcPoint::position().

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The documentation for this class was generated from the following files:

• StEEmcPool/StMaxStripPi0/StEEmcPointUtils.h
• StEEmcPool/StMaxStripPi0/StEEmcPointUtils.cxx