New answers tagged

0

Following Garyp's comment; "r , being the radial coordinate, has no knowledge of direction. Another way to see this is to note that the dipole matrix element has to be a vector. Calculating the rr matrix element gives you just one number. Perhaps more to the point: you want to find the matrix element of r⃗ r→, not rr. – garyp" The dipole element should be; ...


0

You got it almost right. The symmetry of the wavefunction describing a system made of 2 identical boson must be even by the interchange of the 2 bosons because of the Pauli principle. Interchanging the 2 bosons position introduces a factor $(-1)^l$ with $l$ the angular momentum quantum number. Thus among the 2 values allowed by the conservation of angular ...


1

The forces entering the standard model all are symmetric, with zero mass exchange particles at high energies before symmetry breaking. It is one of the beauties of the standard model. Any proposed model for further complexity , preons etc has to predict phenomena which are outside the standard model and at the same time, incorporate the phenomena which ...


0

It's explained here in a lecture from the Clay Mathematics institute: https://www.youtube.com/watch?v=pCQ9GIqpGBI Because Area grows like $r^2$. So the classical "field lines" in a $1/r$ potential aka $1/r^2$ force get less dense, but integration over the surface at all distances still yields a constant. A short range potential gets damped with distance. ...


1

is driven by the electromagnetic force (there is a γ in the Feynman's diagram). you are putting the cart in front of the horse. Interactions are defined by their strength. Stronger, i.e. most probable is the strong interaction and the crossections, i.e. probability distributions , are much larger than the electromagnetic interaction, which is larger than ...


1

Who forbids me to think that the particles are not equipped with a primitive form of identity that arises intelligently to your measurements and you can not behave as a quality? "arises intelligently" is not in the physics domain. It is metaphysics, this assigning intelligence to particles, and there exist such metaphysical "theories" but their ...


0

The use of the term mediator in this question appears to refer to gauge bosons. These couple to fermions or other particles that have their coupling charge. In the case of QCD gluons, the gauge particle of force, has color charge and couples to itself. This Higgs boson or field is not of this nature. The elementary idea is that the Higgs field consists of ...



Top 50 recent answers are included