## Abstract

It has been known that Little Higgs models with T-parity, which can give a dark matter candidate, suffer from the anomalies of given models through the Wess-Zumino-Witten term, which in turn can violate the T-parity. Here we thus introduce a new kind of discrete symmetry called Z-parity, which is a residual gauge symmetry of an additional U (1) symmetry of the extended gauge group of the Little Higgs models. Because Z-parity comes from the gauge symmetry, this discrete symmetry not only remains unbroken under the anomalies but also can give the lightest Z-parity particle, which is stable and becomes a viable dark matter candidate. We also show that there is an allowed parameter space in the global symmetry breaking scale f versus the mass of the dark matter, which satisfies the current relic density of the cold dark matter.

Original language | English |
---|---|

Pages (from-to) | 323-328 |

Number of pages | 6 |

Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |

Volume | 688 |

Issue number | 4-5 |

DOIs | |

Publication status | Published - 2010 May 10 |

### Bibliographical note

Funding Information:C.S.K. was supported in part by Basic Science Research Program through the NRF of Korea funded by MOEST ( 2009-0088395 ) and in part by KOSEF through the Joint Research Program ( F01-2009-000-10031-0 ). J.B.P. thanks S.K. Kang for valuable discussions and encouragement about this Letter and H.S. Lee for his kind and critical opinions.

## All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics