Majorana particles and U(1) charges

[krishna mohan]

Hi...

Recently read that neutrinos can be Majorana particles only because they are singlets under the unbroken U(1) electromagnetic..

I can understand that...Majorana means that the particle is its own antiparticle..this can't happen if it is charged, as the antiparticle should have the opposite charge as the particle...

Does this mean that a Majorana particle cannot have any charge? Or is it fine for it to have charges under symmetries which are broken in our world?


Krishna

 

[tom.stoer]

Neutrinos carry weak isospin

 

[Parlyne]

Hi...

Recently read that neutrinos can be Majorana particles only because they are singlets under the unbroken U(1) electromagnetic..

I can understand that...Majorana means that the particle is its own antiparticle..this can't happen if it is charged, as the antiparticle should have the opposite charge as the particle...

Does this mean that a Majorana particle cannot have any charge? Or is it fine for it to have charges under symmetries which are broken in our world?


Krishna

A Majorana mass term explicitly violates the conservation of any additive charge. Therefore, the only charges that can be carried by a Majorana particle are those belonging to symmetry groups that are broken by the same physics that generates the Majorana mass.

 

[BDOA]

A Majorana mass term explicitly violates the conservation of any additive charge. Therefore, the only charges that can be carried by a Majorana particle are those belonging to symmetry groups that are broken by the same physics that generates the Majorana mass.

This is wrong, A Majorana mass term stops conservation of any charge that reverses under electromagnetic charge conjugation, but is just fine if stays the same under C, but reverses under P, I've been looking at such an axial force for 5+ years, and still believe it is possible.

 

[Parlyne]

This is wrong, A Majorana mass term stops conservation of any charge that reverses under electromagnetic charge conjugation, but is just fine if stays the same under C, but reverses under P, I've been looking at such an axial force for 5+ years, and still believe it is possible.

Several things. First, this thread is almost a year and a half old. Did you really just drag it up out of the ether to tell me I'm wrong?

Second, the charge conjugation that shows up in the definition of a Majorana field is pretty much defined to include all charges (conserved or not), not just EM.

Third, while I already knew that Majorana fields can couple to axial currents, I'm not really clear on the physical implications of what you're suggesting. Are you saying that you have an axial interaction that has the opposite sign behavior under parity than would be expected just from the action of the parity operator on an axial current?