58 research outputs found
eos/eos: EOS Version 0.3
No full textI have just released version 0.3, which you can find here.
Changes since version 0.2.6 include:
fixing a bug in the calculation of Λb→Λμ+μ-;
fixing a bug when plotting univeriate Gaussian constraints;
changing the notation for meson name (M^*_q to M_q^* throughout the code);
adding several constraints on Bs→P and Bs→V form factors;
unifying the code for B→Dℓν and B→πℓν decays;
improving parts of the documentation;
providing means to keep track of EOS references across observables.
Contributors of these changes are:
Christoph Bobeth
Thomas Blake
Nico Gubernari
Danny van Dy
New Physics constraints from rare b → s + (γ, ℓ+ℓ−) decays
No full textThe experimental measurements of flavor-changing neutral-current B-meson decays governed by b → s + (γ, ℓ+ℓ−) transitions have entered a new level of precision. Recent results by Belle, CDF, Babar, and LHCb on B → K(*)ℓ+ℓ− and Bs → μ+μ− decays are used in model-(in)dependent analyses to test the Standard Model predictions and to derive stronger constraints on nonstandard contributions. While in agreement with the Standard Model, they still leave sizable room for new physics
QCD Korrekturen zu B->X_s l^+ l^- im Standard Modell und MSSM
No full textQCD corrections are calculated to the inclusive decay B ->Xs l+ l- at next-to-next-to leading order (NNLL) in perturbation theory within the standard model and the minimal supersymmetric extension of the standard model (MSSM). The consideration of such corrections reduces the occuring unphysical renormalization scale dependencies in the theoretical predictions of the dilepton invariant mass spectrum and the branching ratio from typically 20% to 10%. Furthermore the nonperturbative corrections of a systematic expansion in (LambdaQCD/mb)n up to the order n=3 are taken into account and the arising uncertainties are discussed due to poorly known non-perturbative parameters.In der vorliegenden Arbeit werden QCD-Effekte zu dem inklusiven Zerfall B ->Xs l+ l- in nächst-nächstführender Ordnung (NNLL) in Störungstheorie sowohl innerhalb des Standardmodelles als auch in der minimalen supersymmetrischen Erweiterung des Standardmodelles (MSSM) berechnet. Die Berücksichtigung solcher Korrekturen verringert die dabei auftretenden unphysikalischen Renormierungsskalenabhängigkeiten der differentiellen Zerfallsbreite und des Verzweigungsverhältnisses und führt zu einer Verringerung der Unsicherheiten in theoretischen Vorhersagen von typischerweise 20% auf 10%. Desweiteren werden die Korrekturen einer systematischen Entwicklung in (LambdaQCD/mb)n bis zur Ornung n=3 und die damit verbundenen theoretischen Unsicherheiten durch ungenau bekannte nichtstörungstheoretische Parameter zu obengenannten Observablen diskutiert
Anomalous triple gauge couplings from -meson and kaon observables
No full textWe consider the three CP-conserving dimension-6 operators that encode the leading new-physics effects in the triple gauge couplings. The contributions to the standard-model electromagnetic dipole and semi-leptonic vector and axial-vector interactions that arise from the insertions of these operators are calculated. We show that radiative and rare -meson decays provide, under certain assumptions, constraints on two out of the three anomalous couplings that are competitive with the restrictions obtained from LEP II, Tevatron and LHC data. The constraints arising from the electroweak pseudo observables, and are also studied.We consider the three CP-conserving dimension-6 operators that encode the leading new-physics effects in the triple gauge couplings. The contributions to the standardmodel electromagnetic dipole and semi-leptonic vector and axial-vector interactions that arise from the insertions of these operators are calculated. We show that radiative and rare B-meson decays provide, under certain assumptions, constraints on two out of the three anomalous couplings that are competitive with the restrictions obtained from LEP II, Tevatron and LHC data. The constraints arising from the electroweak pseudo observables, and ϵ /ϵ are also studied.We consider the three CP-conserving dimension-6 operators that encode the leading new-physics effects in the triple gauge couplings. The contributions to the standard-model electromagnetic dipole and semi-leptonic vector and axial-vector interactions that arise from the insertions of these operators are calculated. We show that radiative and rare -meson decays provide, under certain assumptions, constraints on two out of the three anomalous couplings that are competitive with the restrictions obtained from LEP II, Tevatron and LHC data. The constraints arising from the electroweak pseudo observables, and are also studied
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