ΔF = 2 observables and fine-tuning in a warped extra dimension with custodial protection

By M. Blanke, Andrzej Buras, Bjoern Duling, Stefania Gori, A. Weiler. 2008

263 citations recorded by the source corpus.

We present a complete study of ΔS = 2 and ΔB = 2 processes in a warped extra dimensional model with a custodial protection of ZbLL, including eK, ΔMK, ΔMs, ΔMd, ASLq, ΔΓq, ACP(Bd→ψKS) and ACP(Bs→ψ). These processes are affected by tree level contributions from Kaluza-Klein gluons, the heavy KK photon, new heavy electroweak gauge bosons ZH and Z', and in principle by tree level Z contributions. We confirm recent findings that the fully anarchic approach where all the hierarchies in quark masses and weak mixing angles are geometrically explained seems implausible and we confirm that the KK mass scale MKK generically has to be at least ~ 20 TeV to satisfy the eK constraint. We point out, however, that there exist regions in parameter space with only modest fine-tuning in the 5D Yukawa couplings which satisfy all existing ΔF = 2 and electroweak precision constraints for scales MKK 3 TeV in reach of the LHC. Simultaneously we find that ACP(Bs → ψ) and AsSL can be much larger than in the SM as indicated by recent results from CDF and DO data. We point out that for Bd,s physics ΔF = 2 observables the complex (ZH,Z') can compete with KK gluons, while the tree level Z and KK photon contributions are very small. In particular we point out that the ZdiLjL couplings are protected by the custodial symmetry. As a by-product we show the relation of the RS flavour model to the Froggatt-Nielsen mechanism and we provide analytic formulae for the effective flavour mixing matrices in terms of the fundamental 5D parameters.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/1d243d42a3c05576edc255852ad3fd9920f5a5ce

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Citations in the corpus

Higgs Physics at the HL-LHC and HE-LHC (2019, methodology): “Integrating out the Kaluza-Klein (KK) modes of mass mKK , and working in the limit of a brane-localised Higgs, keeping only terms of leading order in v(2)/m(2)KK , the SM quark mass matrices are given by [677] (see also [678, 679, 680, 681, 682, 683, 684, 685, 686], and Ref.”
Flavor violating Higgs decays (2012, background): “The study of FV couplings of the Higgs boson has a long history [6–26].”
Rare K and B Decays in a warped extra dimension with custodial protection (2008, methodology): “10) can be obtained [1, 22].”
Anatomy and phenomenology of FCNC and CPV effects in SUSY theories (2009, methodology): “6 with respect to the expected spectrum at the LHC.”
Electroweak and Flavour Structure of a Warped Extra Dimension with Custodial Protection (2009, methodology): “In order to simplify the phenomenological discussion in [27, 44] we chose to work with the (+− − − −) sign convention for the metric, i.”