GT Chen's Blog

一些常數可以到Particle Data Group裡面下載
Reviews, Tables, and Plots裡的Constants, Units, Atomic and Nuclear Properties
http://pdg.lbl.gov/2007/reviews/contents_sports.html#constantsetc

以下列出一些常用的 並用C的形式寫下 (通常末兩位有誤差)
//--------------CGS unit--------------//
#define C 2.99792458e+10          //speed of light  (cm/sec)
#define H 6.6260693e-27             //Planck const.   (erg sec)
#define bar 1.05457168e-27       //reduced Planck const.  =H/PI (erg sec)
#define K 1.3806505e-16             //Boltzmann const.(erg/K)
#define KT 8.617343e-5               //1 K to eV
#define mp 1.67262171e-24       //proton mass (g)
#define me 9.1093826e-28         //electron mass (g)
#define sigma 5.670400e-5        //Stefan-Boltzmann const.(erg/sec cm^2 K^4)
#define e 4.80320441e-10          //1 charge unit (esu)
#define ee 1.60217653e-12        //1ev to erg     
#define Alpha (1.0/(137.03599911))   //fine-structure constant
#define E 2.718281828459045235              
#define PI 3.141592653589793238

#define Hbar 6.58211915e-16     //reduced Planck const.  =H/PI  (eV sec)
#define M 510998.918                   //electron mass in eV =(me*C*C)/ee   (eV)
#define MP 938272029                 //proton mass in eV =(mp*C*C)/ee   (eV)     
#define Re 2.817940325e-13      //classical electron radius  =((e*e)/(me*C*C)) (cm)
#define RY 13.6056923                //Rydberg enegy (eV)
#define A0 0.5291772108e-8      //Bohr radius (cm)
#define sigma0 0.665245873e-24  //Thomson cross section sigma0 =((8*PI*R0*R0)/3) (cm^2)

//------------Natural Unit------------//  
//Hbar=C=K=1  all parameters are described in eV 
#define Alpha (1.0/(137.03599911))    //fine-structure constant
#define E 2.718281828459045235              
#define PI 3.141592653589793238
#define me 510998.918                 //electron mass (eV)
#define mp 938272029                  //proton mass (eV)
#define charge (sqrt(Alpha/4.0*PI))   //1 charge unit =0.303
 
Note: If magnetic field appears, we might change some numbers in this unit system
           and make them consistent.

#define charge (sqrt(Alpha))        //1 charge unit in this system 
#define BT 6.923e-2                      //1 Gauss to eV^2    energy density=((B*BT)^2)/(8*PI)
#define WC ((charge*B)/me)       //cyclotron freq. of electron (eV)  =11.58 keV*B_12
#define WCI ((charge*B)/mp)      //cyclotron freq. of proton   (eV)
#define R0 ((charge*charge)/me)         //classical electron radius (eV^-1)  =1.428e-8 (1/eV)
#define sigma0 ((8.0*PI*R0*R0)/3.0)   //Thomson cross section (eV^-2)   =1.71e-15 (eV^-2)
#define BCR (me*me/charge)               //critial magnetic field(eV^2) = 3.0557e+12  (eV^2) ==4.413e+13G

一些常用單位轉換與常數：
  *PI=3.141592653589793238         *e=2.718281828459045235    
  *1 G=1e-4 T                                        *1 eV=1.60217653(14)e-19 J
  *1 A=0.1nm                                         *1 dyne=1e-5 N
  *1 erg=1e-7 J                                      *1 barn=1e-28 m^2=1e-24 cm^2
  *1 C=2.99792458e+9 esu               *1 eV=1.78266181(15)e-33 g

  *1 K=((1.3806505e-16*1)/1.6e-12)=8.617343e-5 eV
  *1 G=sqrt(1erg/cm^3)=6.923e-2 eV^2  (in my unit system)
  //*1 G=sqrt((1erg/cm^3)/4*PI)=1.953e-2 eV^2 (from book 1)//
  *1 kg=(1*(3e+8)^2/1.6e-19)=5.61e+35 eV             *1 g=5.61e+32 eV          
  *1 sec=(1/Hbar)=1.52e+15 eV^-1                            
  *1 m=(3e+8)*(1/1sec)= 5.07e+6 eV^-1                   *1 cm=5.06e+4 eV^-1
  *1 GeV=0.389 mb
    可以參考1.Stars as laboratories for fundamental physics:~, Georg G. Raffelt, Appendix A, p.580-582
                    2.Quarks and Leptons:~, F. Halzen, Alan D. Martin, p.12-13
                    3.Introduction to Quantum Field Theory, M. E. Peskin, D. V. Schroeder, Appendix A.6, p.809-810