Published: 2015
Total Pages:
Get eBook
The standard model (SM) of particle physics is spectacularly successful, yet the measured value of the muon anomalous magnetic moment (g-2)? deviates from SM calculations by 3.6?. Several theoretical models attribute this to the existence of a ?dark photon,? an additional U(1) gauge boson, which is weakly coupled to ordinary photons. For this study, the PHENIX experiment at the Relativistic Heavy Ion Collider has searched for a dark photon, U, in ?0,?????????e+e- decays and obtained upper limits of ?(2×10-6) on U-? mixing at 90% C.L. for the mass range 30msubU/sub90 MeV/csup2/sup. Lastly, combined with other experimental limits, the remaining region in the U-? mixing parameter space that can explain the (g-2)sub?/sub deviation from its SM value is nearly completely excluded at the 90% confidence level, with only a small region of 29msubU