The impact of universal extra dimensions on the unitarity triangle and rare K and B decays
By Andrzej Buras, Michael Spranger, A. Weiler. 2002
186 citations recorded by the source corpus.
Abstract We calculate the contributions of the Kaluza–Klein (KK) modes to the KL–KS mass difference ΔMK, the parameter eK, the B0d,s– B 0 d,s mixing mass differences ΔMd,s and rare decays K + →π + ν ν , K L →π 0 ν ν , KL→μ+μ−, B→X s,d ν ν and B s,d →μ μ in the Appelquist, Cheng and Dobrescu (ACD) model with one universal extra dimension. For the compactification scale 1/R=200 GeV the KK effects in these processes are governed by a 17% enhancement of the ΔF=2 box diagram function S(xt,1/R) and by a 37% enhancement of the Z0 penguin diagram function C(xt/1/R) relative to their Standard Model (SM) values. This implies the suppressions of |Vtd| by 8%, of η by 11% and of the angle γ in the unitarity triangle by 10°. ΔMs is increased by 17%. ΔMK is essentially uneffected. All branching ratios considered in this paper are increased with a hierarchical structure of enhancements: K + →π + ν ν (16%) , K L →π 0 ν ν (17%) , B→X d ν ν (22%) , (K L →μ μ ) SD (38%) , B→X s ν ν (44%) , B d →μ μ (46%) and B s →μ μ (72%) . For 1/R=250 (300) GeV all these effects are decreased roughly by a factor of 1.5 (2.0). We emphasize that the GIM mechanism assures the convergence of the sum over the KK modes in the case of Z0 penguin diagrams and we give the relevant Feynman rules for the five-dimensional ACD model. We also emphasize that a consistent calculation of branching ratios has to take into account the modifications in the values of the CKM parameters. As a byproduct we confirm the dominant O (g 2 G F m t 4 R 2 ) correction from the KK modes to the Z 0 b b vertex calculated recently in the large mt limit.
Subfields: Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/4d3930371670f18a2206764bfcc123fe57575a63
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In Nuclear and High Energy Physics
Citations in the corpus
- Discrimination of supersymmetry and universal extra dimensions at hadron colliders (2005, background): “KK parity conservation also implies that the contributions to various low-energy observables [27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37] only arise at loop level and are small.”
- Flavor Physics in the Quark Sector (2009, methodology): “This happens for example in the MSSM from chargino-squark loops at moderate tanβ [833–837] or charged-Higgsquark loops at large tanβ [828], with R-parity violation [838–840], in little Higgs models without [170] and with [171–173, 841] T-parity, and in the presence of extra-dimensions [181, 663, 842”