TCAEP.co.uk :: Science-Constants-Fine Structure Constant TCAEP.co.uk :: Welcome to TCEAP.co.uk
TCAEP.CO.UK
 

Science

Constants
  Name Fine Structure Constant
 
  Symbol α
 
  Value 7.297 352 533 ± 0.000 000 027 × 10 −3
 
  Category General Physical Constants
 
  Comments   Each vertex within a Feynman diagram contributes a factor of   α = e 2 4 π ε 0 ℏ c ∼ 1 137 to the matrix element. Thus, although there are an infinite number of allowable Feynman diagrams for every allowed process, those diagrams with more vertices contribute less.

Relativistic corrections to the expression for the energy of the electrons in the atom are α2 as big as the non-relativistic value of the energy. Hence the size of α determines the scale of the fine structure of the spectrum of the atom.

The most accurate determination of the fine structure constant comes from measurements of the electron magnetic moment anomaly.
 
  References The CRC Handbook of Chemistry and Physics, 81st edition, 2000-2001

Introduction to Elementary Particles, D Griffiths, John Wiley & Sons, 1987
  Developed By
Domex e-Data Pvt., Ltd.,