class AliPWG0Helper: public TObject

 Checks if a vertex meets the needed quality criteria

 Get the vertex from the ESD and returns it if the vertex is valid

 Second argument decides which vertex is used (this selects
 also the quality criteria that are applied)

 this function checks if a particle from the event generator (i.e. among the nPrim particles in the stack)
 shall be counted as a primary particle

 This function or a equivalent should be available in some common place of AliRoot

 WARNING: Call this function only for particles that are among the particles from the event generator!
 --> stack->Particle(id) with id < stack->GetNprimary()

 create projections of 3d hists to all 2d combinations
 the histograms are not returned, just use them from memory or use this to create them in a file

 create projections of the 3d hists divides them
 axis decides to which plane, if axis is 0 to all planes
 the histograms are not returned, just use them from memory or use this to create them in a file

 returns the title of the axis given in axis (x, y, z)

 Finds the first mother among the primary particles of the particle identified by <label>,
 i.e. the primary that "caused" this particle

 Finds the first mother among the primary particles of the particle identified by <label>,
 i.e. the primary that "caused" this particle

 returns its label

 normalizes a 1-d histogram to its bin width

 normalizes a 2-d histogram to its bin width (x width * y width)

 Prints the given configuration

 calculates rapidity keeping the sign in case E == pz

 return if process is single diffractive on hadron level

 xiMax and xiMin cut on M^2/s

 Based on code from Martin Poghoysan