English

The "4th generation", B-CP anomalies & the LHC

High Energy Physics - Phenomenology 2009-07-14 v1

Abstract

Attention is drawn to the several 2-3 σ\sigma "anomalies" in B, BsB_s mixings and decays involving CP-observables. Perhaps the most interesting theoretical scenario that could cause such effects is based on warped extra-dimensional models and indeed some of the effects were predicted there. However, a rather simple explanation is that based on a fourth family of quarks with masses in the range of(400 - 600) GeV. The built-in hierarchy of the 4×\times4 mixing matrix is such that the tt' readily provides a needed {\it perturbation} (15\approx 15%) to sin2β\sin 2 \beta as measured in BψKsB \to \psi K_s and simultaneously is the dominant source of CP asymmetry in BsψϕB_s \to \psi \phi. The latter mode is theoretically very clean (unlike the others) and therefore it would be extremely desirable that Fermilab gives a very high priority to clarify this anomaly at the earliest. 4th family explanation allows, with relative ease, to accomodate the stringent flavor changing constraints which usually can be quite challenging for new physics scenarios.Implications for the LHC are briefly discussed; tt' and bb' lead to high ptp_t multilepton events, in particular bb' decays produce rather distinctive same sign leptons with asymmetric energies.

Keywords

Cite

@article{arxiv.0907.2057,
  title  = {The "4th generation", B-CP anomalies & the LHC},
  author = {Amarjit Soni},
  journal= {arXiv preprint arXiv:0907.2057},
  year   = {2009}
}

Comments

14 pages, 6 figures, invited talk at the EW session of Moriond 2009