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arXiv · 1012.0338

Saving fourth generation and baryon number by living long

Hitoshi Murayama·Vikram Rentala·Jing Shu·Tsutomu T. Yanagida
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Abstract

Recent studies of precision electroweak observables have led to the conclusion that a fourth generation is highly constrained. However, we point out that a long-lived fourth generation can reopen a large portion of the parameter space. In addition, it preserves baryon and lepton asymmetries against sphaleron erasure even if $B-L=0$. It opens up the possibility of exact $B-L$ symmetry and hence Dirac neutrinos. The fourth generation can be observed at the LHC with unique signatures of long-lived particles in the near future.

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Hitoshi Murayama, Vikram Rentala, Jing Shu, Tsutomu T. Yanagida. 2010-12-01. Saving fourth generation and baryon number by living long. https://doi.org/10.1016/j.physletb.2011.09.094

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