#ifndef CLASSIC_Physics_HH
#define CLASSIC_Physics_HH

// ------------------------------------------------------------------------
// $RCSfile: Physics.h,v $
// ------------------------------------------------------------------------
// $Revision: 1.1.1.1 $
// ------------------------------------------------------------------------
// Copyright: see Copyright.readme
// ------------------------------------------------------------------------
//
// Namespace: Physics
//
// ------------------------------------------------------------------------
// Class category: Physics
// ------------------------------------------------------------------------
//
// $Date: 2000/03/27 09:32:37 $
// $Author: fci $
//
// ------------------------------------------------------------------------


// Class Physics
// ------------------------------------------------------------------------
/// A namespace defining various mathematical and physical constants.

namespace Physics {

    /// The value of \f[ \pi \f]
    extern const double pi;

    /// The value of \f[2 \pi \f]
    extern const double two_pi;

    /// The value of \f[ \frac{1}{2} \pi \f]
    extern const double u_two_pi;

    /// The value of \f[ e \f]
    extern const double e;

    /// The logarithm of $e$ to the base 10
    extern const double log10e;

    /// The velocity of light in m/s
    extern const double c;

    /// The permeability of vacuum in Vs/Am
    extern const double mu_0;

    /// The permittivity of vacuum in As/Vm
    extern const double epsilon_0;

    /// The reduced Planck constant in GeVs
    extern const double h_bar;

    /// The Avogadro's number
    extern const double Avo;

    /// Boltzman's constant in eV/K.
    extern const double kB;

    /// The elementary charge in As
    extern const double q_e;

    /// The fine structure constant, no dimension
    extern const double alpha;

    /// The electron rest mass in GeV
    extern const double m_e;

    /// The classical electron radius in m
    extern const double r_e;

    /// The reduced Compton wave length for electrons in m
    extern const double lamda_e;

    /// The magnetic momentum anomaly for electrons, no dimension
    extern const double a_e;

    /// The proton rest mass in GeV
    extern const double m_p;

    /// The carbon rest mass in GeV
    extern const double m_c;

    /// The uranium rest mass in GeV
    extern const double m_u;

    /// The muon rest mass in GeV
    extern const double m_mu;

    /// The h- rest mass in GeV
    extern const double m_hm;

    /// The xenon rest mass in GeV
    extern const double m_xe;

    /// The deuteron rest mass in GeV
    extern const double m_d;

    /// The classical proton radius in m
    extern const double r_p;

    /// The reduced Compton wave length for protons in m
    extern const double lamda_p;

    /// The magnetic momentum anomaly for protons, no dimension
    extern const double a_p;

    /// The charge of proton
    extern const double z_p;

    extern const double EMASS;

    extern const double PMASS;

    extern const double PCHARGE;

    // alfven current
    extern const double Ia;
    // e/mc
    extern const double e0mc;
    // e/m
    extern const double e0m;

};

#endif // CLASSIC_Physics_HH