\defgroup Physics Physics Vectors
\ingroup Math
\brief The Physics Vectors classes.

Several documents describing these classes are listed below:

  - The main histogram class is documented in class TGeoManager.
  - [The Chapter about the Physics Vectors classes in the Users Guide](ftp://root.cern.ch/root/doc/17PhysicsVectors.pdf)

#### The Physics Vector package consists of five classes:
  - TVector2
  - TVector3
  - TRotation
  - TLorentzVector
  - TLorentzRotation

It is a combination of CLHEPs Vector package written by
Leif Lonnblad, Andreas Nilsson and Evgueni Tcherniaev
and a ROOT package written by Pasha Murat.
for CLHEP see:  http://www.cern.ch/clhep/