Anomalous magnetic moment of electron

introduction

• amplitude = sum of integrals = \(\sum_{n\text{ loops}}\) sum of integrals
• anomalous electron magnetic dipole moment 1.00115965219
• theoretical computation matches 11 digits with experiments
• as n grows, number of Feynman diagrams grows exponentially
• integrals are becoming difficult

 

 

classical magnetic moment

• copied from spin system
• A classical electron moving around a nucleus in a circular orbit
  
  • orbital angular momentum, L=m_evr
  • magnetic dipole moment, \mu= -evr/2
  • where e, m_e, v, and r are the electron´s charge, mass, velocity, and radius, respectively.
• A classical electron of homogeneous mass and charge density rotating about a symmetry axis
  
  • angular momentum, L=(3/5)m_eR^2\Omega
  • magnetic dipole moment, \mu= -(3/10)eR^2\Omega, where R and \Omega are the electron´s classical radius and rotating frequency
• gyromagnetic ratio \(\gamma = \mu/L=-e/2m_e\)
  [/pages/7141159/attachments/4562863 I15-62-g20.jpg]
  
• pictures from Gyromagnetic Ratio and Anomalous Magnetic Moment

 

 

anamalous electron magnetic dipole moment

• In Dirac’s theory a point like spin 1/2 object of electric charge q and mass m has a magnetic moment\[\mathbf{\mu}=q\mathbf{S}/m\]
• classical vs quantum
  [/pages/3589069/attachments/4562673 2004329152457_150.gif]
  

 

• The g factor sets the strength of an electron’s interaction with a magnetic field.
• In classical physics (left) magnetic lines of force (perpendicular to the page) induce a curvature in the electron’s path.
• In quantum electrodynamics (right) the electron interacts with the field by emitting or absorbing a photon.
• The event is represented in a Feynman diagram, where space extends along the horizontal axis and time moves up the vertical axis.
• \(g=2(1+c_1\frac{\alpha}{2\pi}+c_2(\frac{\alpha}{2\pi})^2+c_3(\frac{\alpha}{2\pi})^3+\cdots)\)
• http://www.wolframalpha.com/input/?i=fine+structure+constant
• http://www.wolframalpha.com/input/?i=1/fine+structure+constant

 

• http://docs.google.com/viewer?a=v&q=cache:5hOX9DCrL7sJ:www.physics.ohio-state.edu/~kass/P780_L3_sp03.ppt+anamalous+magnetic+moment+electron+feynman+diagram&hl=ko&gl=us&pid=bl&srcid=ADGEEShmuOjISGxcCejbd6l7kWuRiTY7AtBHwKpZ_Zec4dSTPlJ8kqZSA80srABAl8PEFKnJJVfrawIHlkI0Z9S5wA1ArJMpmMERZp3I3ppK4BN5drRWx4mJi8VTW_wf8xjrs3v1VOqX&sig=AHIEtbTIAIEubf5ZHYPXPv4aE6ImvmxEVw
• [1]http://universe-review.ca/R15-12-QFT.htm
  

 

 

 

 

 

 

two-loop diagrams

• 7 two-loop diagrams
  [/pages/3589069/attachments/4562669 2004329153354_150.gif]
  [/pages/7141159/attachments/4562733 I15-62-g2c.jpg]
  

 

 

three-loop diagrams

• 72 three-loop diagrams
• [/pages/3589069/attachments/4562671 200432915395_150.gif]

• Toichiro Kinoshita

 

four-loop diagrams

•  891 diagrams

• Numerical calculation of electron g-2 at 4 loops in QED S. Laporta
  

 

 

five-loop Feynman diagrams

• There are 12,672
• http://www.strings.ph.qmul.ac.uk/~bigdraw/feynman/slide3.html[2]

 

 

 

anaomalous muon magnetic dipole moment

• anaomalous muon magnetic dipole moment is still unknown
  
• http://eskesthai.blogspot.com/2010/12/muon.html
  

 

 

memo

• Calculation of the Anomalous Magnetic Moment of the Electron from the Evans-Unified Field Theory
  

 

 

history

• http://www.google.com/search?hl=en&tbs=tl:1&q=

 

 

 

 

encyclopedia

• number of Feynman diagrams http://oeis.org/A005413
• http://en.wikipedia.org/wiki/Anomalous_magnetic_dipole_moment
• http://en.wikipedia.org/wiki/
• http://www.scholarpedia.org/
• http://www.proofwiki.org/wiki/
• Princeton companion to mathematics(Companion_to_Mathematics.pdf)

 

 

books

 

• 2011년 books and articles
• http://library.nu/search?q=
• http://library.nu/search?q=

 

 

expositions

• Brian Hayes, “g-OLOGY,” American Scientist 92, no. 3 (2004): 212. http://www.americanscientist.org/issues/num2/g-ology/1

 

 

articles

 

• http://www.ams.org/mathscinet
• http://www.zentralblatt-math.org/zmath/en/
• http://arxiv.org/
• http://www.pdf-search.org/
• http://pythagoras0.springnote.com/
• http://math.berkeley.edu/~reb/papers/index.html
• http://dx.doi.org/

 

 

question and answers(Math Overflow)

• http://mathoverflow.net/search?q=
• http://mathoverflow.net/search?q=

 

 

blogs

• 구글 블로그 검색
  
  • http://blogsearch.google.com/blogsearch?q=
    
  • http://blogsearch.google.com/blogsearch?q=
• http://ncatlab.org/nlab/show/HomePage

 

 

experts on the field

• http://arxiv.org/

 

 

links

• Detexify2 - LaTeX symbol classifier
• 수식표현 안내
• The On-Line Encyclopedia of Integer Sequences
• http://functions.wolfram.com/