The transformation of two "colliding" photons into a pair of particle / anti-particle was experimentally observed already. But the observed particles are always electrically charged.
1. If such a transformation takes place in vacuum, and the pair annihilates after a short time, then no interaction with other real particles occurs (apart from virtual particles in vacuum). If under these circumstances a pair of magnetically charged particles were generated, could the mass of each particle roughly equal the mass of an "otherwise similar" electrically charged particle? I.e., if we permit the existence of magnetic monopoles at all for the moment, could we assume magnetic counterparts to electron and positron, for example, without immediately generating paradoxes? (The theoretical lower limit for the mass of magnetic monopoles in condensed matter is usually calculated as being much larger than the mass of an electron.)
2. If magnetic monopoles were generated by photon/photon collisions, do you think they could be / would be detected under the standard experimental conditions? (For example, the usual spiral shaped paths would occur only in a strong electric field instead of the usual magnetic field. And besides that, the use of a cloud chamber is incompatible with the above assumption "no interaction with other real particles".)
3. If the anwer to question 2 is "no", do you know of attempts to observe magnetic monopoles generated by two photons? (If I'm not mistaken previous attempts to prove the existence of magnetic monopoles were directed toward single, relatively long-lasting monopoles, not necessarily generated inside the experimental setup.)
Many thanks in advance for answers and links to publications related to this topic!