I was wondering whether the decay of the Pi-0 meson in QED to an electron positron pair can occur as follows:
Pi-0 -> virtual photon -> e+e-
or does it have to go via
Pi-0 -> two virtual photons -> e+e- (the Feynman diagram has a 'square' of virtual electrons/photons)?
I'm struggling with the relation between particle exchange and parity with the case of para- and ortho-hydrogen.
The overall wavefunction must be antisymmetric with respect to particle exchange and so for para-hydrogen (an antisymmetric spin state) the spatial part of the wavefunction must be...
Firstly, apologies for the notation.
The 4-momentum of a massive particle (rest mass m) is defined by
where u is the 4-velocity. Thus in a frame S in which a particle has 3-velocity u the components of p are
How can we then identify the zeroth component of...
A stone is dropped from a stationary helicopter 500m above the ground, at the equator. How far from the point vertically below the helicopter does it land?
Conversation of AM
The Attempt at a Solution
Let the height above the ground it is...
So, the rocket equation is
F_ext = m(dv/dt) + u(dm/dt)
where m is the mass of the rocket, v the velocity, u the effective exhaust gases speed, and F_ext the external forces on the system.
If we take a constant mass ejection rate p, and take the external force to be the gravitational...
I'm getting confused with different types of acceleration when dealing with rotating systems. There is centripetal acceleration, tangential acceleration, and angular acceleration as far as i know. How do you derive that linear momentum equals angular momentum multiplied by the radius?