Jul 20 – 27, 2011
Alpes Congrès - Alpexpo
Europe/Paris timezone

Neutron EDM in Four Generation Standard Model

Jul 21, 2011, 9:00 AM
Oisans (Alpes Congrès - Alpexpo)


Alpes Congrès - Alpexpo

Parallel session talk Flavour Physics and Fundamental Symmetries Flavour Physics and Fundamental Symmetries


Dr Fanrong Xu (National Taiwan University)


New experiments under construction aim to push neutron electric dipole moment down by one to two orders of magnitude, to an eventual sensitivity of 10^{−28} e cm. The Standard Model would still be out of reach. However, there is renewed interest in the direct search for a possible fourth generation of quarks, which may carry sufficient CP violation for the baryon asymmetry of the Universe. We estimate the neutron EDM in the presence of a fourth generation, and find it would be dominated by the strange quark chromoelectric dipole moment, assuming it does not get wiped out by a Peccei-Quinn symmetry. The three electroweak loop contribution is comparable in strength to the two-loop electroweak/one-loop gluonic contribution. With m_{b′}, m_{t′} at 500 GeV or so, and with a Jarlskog CPV factor that is consistent with hints of New Physics in b → s transitions, the neutron EDM is still far below 10^{−28} e cm.

Primary authors

Dr Fanrong Xu (National Taiwan University) Prof. Junji Hisano (Nagoya University and University of Tokyo) Prof. Wei-Shu Hou (National Taiwan University)

Presentation materials