Confused by the branching ratio of uds ---> proton + e- + neutrino compared to uds ---> proton + pion (or neutron + pion).
In both cases an W boson is being produced as the strange quark changes flavour, and it is either decaying to leptons or first generation quarks - why is the leptonic...
Homework Statement
A Lorenz system is given by
x' = sy - sx
y' = 3sx - y - xz
z' = xy - bz
In the vicinity of point x = y = 2s, z=4s , for s>>b, show motion is aligned with the y,z plane (sub these values in and x' is 0). By considering the evolution of vectors [2,0,1+sqrt(5)] , [0,1,0]...
Homework Statement
Nearly free electron model in a 2D lattice. Consider a divalent 2D metal with a square lattice and one atom per primitive lattice cell. The periodic potential has two Fourier components V10 and V11, corresponding to G = (1,0) and (1,1). Both are negative and mod(V10) >...
Homework Statement
Silicon crystalises in a cubic structure whose lattice is face-centred, with a basis [000],[1/4,1/4,1/4].
How many optic/acoustic modes are to be found in the phonon dispersion diagram for silicon. How many distinct branches would you expect along the [100] direction...
Sorry made a silly mistake. So the BR should be 60% for hadrons and 20% for the electron
Sorry made a silly mistake. BR should now be 60% for hadrons (3 * cos^2(x) + sin^2(x)) / (3 * (cos^2(x) + sin^2(x)) + 1 + 1 ) , and 20% for each lepton. Many thanks.
I'm afraid I just can't see it. I'v
Many thanks for your reply. I can see I shouldn't have include the charm containing mesons as they are slightly to heavy. This brings the branching ratios to 50% hadrons and 25% for each lepton. Have I missed something else or is the remaining discrepancy...
Homework Statement
Branching ratios of tau lepton decay:
hadrons 66%
muon 17%
electron 17%
Use your knowledge of the decay of W bosons to justify these rates.
Homework EquationsThe Attempt at a Solution
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The W+ boson can decay to any combination of quarks with +1 charge, but the CKM...
Homework Statement
Show Kepler's Third Law holds for circular Schwarzschild orbits.
Homework Equations
The Attempt at a Solution
Setting r' = 0 , \theta' = 0 and \theta = \pi / 2 , where the derivatives are with respect to the variable \lambda and setting c = 1 the Lagrangian is...
Homework Statement
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In Minkowski spacetime we are considering a (series of) frame(s), S', attached to a rocket with constant proper acceleration. The rocket's speed in S is v.
We find with boundary conditions x = 0 at t = t' = 0 the relationships between S and S' (for x' = 0, i.e. at the...
Homework Statement
Rocket is accelerating constantly. Let S' be instantaneous rest frame of rocket and S be frame in which rocket is observed moving at velocity v.
Homework Equations
Given: $$ dv = dv' (1 - v^2) $$
Must prove:
$$ \frac{dv}{dt} = \frac{dv'}{dt'} (1 -...
Homework Statement
What effect would placing an LC circuit in a steady magnetic field have have on its resonant frequency? The inductor contains a paramagnet. This is asked about at very low temperature.
Homework EquationsThe Attempt at a Solution
Apart from initial changes due to Lenz's Law...
Thanks for your response Chet.
∇T ≈ ΔT / s , where s is the gap between cylinders if we assume that ∇T is constant. However s is not given.
The expression for κ assumes the mean free path is much less than the size of the container, so the molecules collide with each other much more frequently...
Homework Statement
A vacuum flask of radius r and length l consists of two concentric cylinders separated by a narrow gap containing a gas at pressure 10^-2 Nm^-2. The liquid in the flask is at 60 degrees Celcius and the air outside is at 20 degrees celcius. Estimate the rate of heat loss by...