Flavour Changing Neutral Current Effects from Flavour Dependent Supergravity Couplings

نویسندگان

  • Ph Brax
  • C A Savoy
چکیده

We investigate the impact on low energy flavour mixing phenomena of the renormalisation group running of parameters in supersymmetric theories. We have explicitly chosen flavour dependent supergravity couplings. The renormalisation group equations are displayed in general matrix form. We work in a scale dependent basis such that the hierarchy in the quark masses can be more easily utilised. Simple analytic solutions are provided in matrix form (for general boundary conditions) when only the third generation Yukawa couplings are retained in the renormalisation group equations. We solve the evolution equations of the KM matrix and the supersymmetry breaking soft terms in the squark sector. We suggest a general parametrisation of the soft analytic terms, more suitable for non-universal supergravity couplings. We point out that for flavour dependent soft terms, there are new contributions to the neutron electric dipole moment. Finally, we consider a model with maximal flavour mixing in order to estimate the effects due to the renormalisation scale dependence.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Flavour constraints on multi-Higgs-doublet models: Yukawa alignment

In multi-Higgs-doublet models, the alignment in flavour space of all Yukawa matrices coupling to a given right-handed fermion guarantees the absence of tree-level flavour-changing neutral couplings, while introducing new sources of CP violation. With N Higgs doublets (and no right-handed neutrinos) the Yukawa Lagrangian is characterized by the fermion masses, the CKM quark mixing matrix and 3(N...

متن کامل

Multilepton production via top flavour-changing neutral couplings at the CERN LHC

Zt and γt production with Z → ll and t → Wb → lνb provides the best determination of top flavour-changing neutral couplings at the LHC. The bounds on tc couplings eventually derived from these processes are similar to those expected from top decays, while the limits on tu couplings are better by a factor of two. The other significant Z and W decay modes are also investigated. PACS: 12.15.Mm, 12...

متن کامل

Four-Loop Anomalous Dimensions for Radiative Flavour-Changing Decays

We evaluate the complete four-loop anomalous dimension matrix that is necessary for determining the effective flavour-changing neutral current couplings q̄qγ and q̄qg at the nextto-next-to-leading order in QCD. The resulting O(α s(μb)) correction to the B̄ → Xsγ branching ratio amounts to around −2.9% for μb = 5GeV, and −4.4% for μb = 2.5GeV.

متن کامل

Supersymmetric effects in rare semileptonic decays of B and K mesons

Rare flavour-changing neutral-current transitions of the type s → d ll(νν̄) and b → s ll(νν̄) are analysed in supersymmetric extensions of the Standard Model with generic flavour couplings. It is shown that these processes are particularly sensitive to the left–right mixing of the squarks and that, in the presence of non-universal A terms, they could lead to unambiguous signatures of new physics ...

متن کامل

ar X iv : 0 90 8 . 15 54 v 2 [ he p - ph ] 1 3 N ov 2 00 9 Yukawa Alignment in the Two - Higgs - Doublet Model

In multi-Higgs-doublet models the alignment in flavour space of the relevant Yukawa matrices guarantees the absence of tree-level flavour-changing couplings of the neutral scalar fields. We analyze the consequences of this condition within the two-Higgs-doublet model and show that it leads to a generic Yukawa structure which contains as particular cases all known specific implementations of the...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1995