Why don't elementary particles with spin $\frac{3}{2}$ exist?
32932
What are the mathematical problems in introducing Spin 3/2 fermions?
94430
Examples of number theory showing up in physics
73858
Electron spin g-factor
120820
Why, in spin sums, we sum over final spin states and average over initial states?
77742
Queries about rotational groups $\mathrm{SO}(3)$ and $\mathrm{SU}(2)$ in QM
70774
Why can't the Schrödinger equation be solved exactly for multi-electron atoms? Does some solution exist even in principle?
64212
Dirac, Weyl and Majorana Spinors
45283
Why don't virtual particles violate conservation of mass/energy?
90917
Why do we have an elementary charge but no elementary mass?
8241
Why doesn't the deuterium nucleus have spin $0$?
35409
Massless charged particles
43659
Why is $\pi$ so close to $3$?
105323
Why can't gravitons be created in traditional particle accelerators?
123657
Why do physicists think that the electron is an elementary particle?
89420
Can quarks be considered real and elementary?
88637
Why can a particle decay into two photons but not one?
44953
Gauge symmetries and elementary particles