Recent content by ansgar

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    Graduate Phenomenological Nuclear Theory

    the drop model can't explain excited states etc, it is a classical model
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    Graduate Phenomenological Nuclear Theory

    what about the shell model for instance?
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    Undergrad Why is light affected by gravity?

    gravity affects energy, not mass
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    Graduate A massive force carrying particle? The weak nuclear force, the W boson has mass?

    why not, it is virtual and does not satisfy E^2 = P^2 + M^2
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    Graduate Do Fermionic Creation and Annihilation Operators Commute?

    yes they satisfy that, but that is called ANTIcommute
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    Graduate Problem with anticommutation of spinors

    In e.g. Burgess and Moore - standard model a primer it is stated that for two spinors (majorana) \bar{\psi_1}\psi_2 = (\bar{\psi_1}\psi_2)^T = - \psi_2^T \bar{\psi_1}^T since the spinors are anticommuting objects, thus ordering reversion gives -1 but they also state that...
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    Graduate Why is the QCD vacuum important in non-abelian gauge theories?

    see my presentation about this topic: http://www.isv.uu.se/~wouda/axion-beamer-GW.pdf
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    How Can I Bridge the Gap Between Landau and Griffiths in Electrodynamics?

    Have you studied at Uppsala?
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    Graduate Genereral:Questions about Srednicki's QFT

    1 means singlet, 2 means doublet.. it is "just" adding of two spin 1/2 particles, same algebra.
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    Graduate What is the CP operator on pion combinations?

    write the state for the pi0 in terms quarks
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    Graduate Genereral:Questions about Srednicki's QFT

    you might want to go back to basic QM... it is a number since phi(0) is a number here is a good review of those particular chapters from srednicki www.physics.indiana.edu/~dermisek/QFT_09/qft-II-1-4p.pdf
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    Graduate Genereral:Questions about Srednicki's QFT

    no the specral density is only a function of s use eq. 13.9 we get |< k,n | phi(0) | 0 >|^2 which is just a (complex) number.
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    Graduate Why Does the Electron Jump Between Stationary States?

    if you want the explanation just pick up a QFT book and get your hands dirty. the vacuum is not the vacuum of fields though, only vacuum of particle field excitations
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    Graduate Genereral:Questions about Srednicki's QFT

    what happens if you actually is doing the math for the RHS of that equation? what does it become? Use \phi(x)=\int d^3 \tilde k [a(k,t)e^{ikx}+a^\dagger(k,t)e^{-ikx}] which according to xepma is true where now the a is the annihilation operator for the true vacuum |\Omega...
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    Graduate Compton Cross Section: Derivation & Relation

    eq. 6 http://www.physics.usyd.edu.au/~kuncic/lectures/HEA_L10.pdf