Recent content by charlesmartin14

No I was thinking more to use a relation like $$\delta[g(x)]=\dfrac{\delta(x-x_{0})}{|g'(x)|_{x=x_{0}}}$$ or maybe the simpler relation $$\delta[(x^{2}-a^{2})]=\dfrac{1}{2|a|}[\delta(x+a)+\delta(x-a)]$$ so that we can reduce...

∫dJδ(J2-N)≈exp(N/2(1+ln2π)) The area of an N-sphere goes like 2πN/2 so I know this is close but I am haven't remembered the trick yet how to get the exact result

Problem Statement: I am trying to understand how to compute the surface an N-sphere , for large N, to leading order (and exactly) Given a vector J with norm N, with N large, how does one compute the volume integral ? That is, what representation of the delta function. And what is the exact...

Mossbauer spectroscopy is an example of a nuclear (de)excitation coupling to a lattice phonons Are there any other examples of this phenomena ?

Whatever the experimentalists tell me their best estimate it. The nuclear radius can be estimated using a simple formula R\sim A^{\frac{1}{3}} where A is the Atomic mass number. I am asking how the Fermi VA theory is typically used in very detailed calculations.

The Lagrangian contains a 'contact potential' , which Fermi assumed is a contact coupling of two vector currents. (prior to when parity breaking was discovered. This is now part of the Standard Model, in some cryptic form. IMHO, you can not see it obviously in the Lagrangian until you specify...

Where is the electron-nucleon interaction? On the surface of the nucleus, or at the origin (R-0) ?

Do Fermi and Gamow-Teller transitions only refer to changes in isospin , as in beta decay and orbital electron capture

Im try to understand this paper http://citeseerx.ist.psu.edu/vie... and see if I correctly understand which processes are charge-current processes, and which are charge neutral, as listed in Figure 1. Thanks

Thanks ! That makes perfect sense. this is a great forum

I am trying to derive the 2+2 body relativisitic cross section, as given in https://web2.ph.utexas.edu/~schwitte/PHY362L/QMnote.pdf a+b -> c+d I want the form of the cross section dσ/dΩ ~ 1/((v_i)(v_f)) I am stuck on step (13)-(14) and I don't understand why d√s/dp_f=v_f Here, s is the...

Homework Statement I am trying to derive the 2 body cross section, as given in https://web2.ph.utexas.edu/~schwitte/PHY362L/QMnote.pdf dσ/dΩ Homework Equations I am stuck on d√s/dp=v where √s=(Ea+Eb)=E The Attempt at a Solution p=Ev (relativisitic energy-momentum relationship) √s=E...

I have a PhD in Theoretical chemistry and did my postdoctoral work in the Theoretical Bio/Physics group. I am finally getting around to learning some relativisitic theory.