
Fleeting alchemy: lead briefly becomes gold in the LHC
At the LHC's ALICE experiment, ultraperipheral lead-208 collisions produce gold-205 briefly via photon exchange, with a cross section near 6.8 barns and a lifetime of about 1e-23 seconds. This clean, photon-driven process lets physicists probe nuclear structure and QED at high energy and informs future collider design.






