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r3 - 04 Mar 2012 - 16:18 - DenisDerkach |
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r2 - 04 Dec 2011 - 21:56 - DenisDerkach |
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Fit results: Winter 2011 (post-LP11) |
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Fit results: Winter 2011 (post-LP11) |
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The fit results for all the nine CKM elements are  |
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The fit results for all the nine CKM elements are  |
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In principle, the presence of New Physics might affect the result of the UT analysis, changing the functional dependencies of the experimental quantities upon ? and ?. On the contrary, two constraints now available, are almost unchanged by the presence of NP: |Vub/Vcb| from semileptonic B decays and the UT angle ? from B ? D(*)K decays. As usual from this fit one can gets predictions for each observable related to the Unitarity Triangle. This set of values is the minimal requirement that each model describing New Physics has to satisfy in order to be taken as a realistic description of physics beyond the Standard Model. The fit results for all the nine CKM elements are  |
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The fit presented here is meant to constrain the NP contributions to |? F|=2 transitions by using the available experimental information on loop-mediated processes In general, NP models introduce a large number of new parameters: flavour changing couplings, short distance coefficients and matrix elements of new local operators. The specific list and the actual values of these parameters can only be determined within a given model. Nevertheless mixing processes are described by a single amplitude and can be parameterized, without loss of generality, in terms of two parameters, which quantify the difference of the complex amplitude with respect to the SM one. Thus, for instance, in the case of mixing we define where includes only the SM box diagrams, while also includes the NP contributions. In the absence of NP effects, and by definition. In a similar way, one can write Concerning , to be conservative, we add to the short-distance contribution a possible long-distance one that varies with a uniform distribution between zero and the experimental value of . The experimental quantities determined from the mixings are related to their SM counterparts and the NP parameters by the following relations: in a self-explanatory notation. All the measured observables can be written as a function of these NP parameters and the SM ones ? and ?, and additional parameters such as masses, form factors, and decay constants. Click on the parameter name to jump to the corresponding plot The fit results for all the nine CKM elements are  |
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It is possible to generalize the full UTfit beyond the Standard Model to all those NP models characterized by Minimal Flavour Violation, i.e. having quark mixing ruled only by the Standard Model CKM couplings ( http://arxiv.org/abs/hep-ph/0007085). In fact, in this case no additional weak phases are generated and several observables entering into the Standard Model fit (the tree-level processes and the measurement of angles through the use of time dependent CP asymmetries) are not affected by the presence of New Physics. The only sizable effect we are sensitive to is a shift of the Inami-Lim function of the top contribution in meson mixing. This means that in general ?K and ?md cannot be used in a common SM and MFV framework. Also the ratio ?md/?ms cannot be used in general, as ?ms can get additional NP contributions at large tan?. So, simply removing the information related to ?K, ?md and ?ms from the full UTfit, one can obtain a more precise determination of the Universal Unitarity Triangle, which is a common starting point for the Standard Model and any MFV model. The fit results for all the nine CKM elements are  |
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The fit presented here is meant to constrain the NP contributions to |? F|=2 transitions by using the available experimental information on loop-mediated processes In general, NP models introduce a large number of new parameters: flavour changing couplings, short distance coefficients and matrix elements of new local operators. The specific list and the actual values of these parameters can only be determined within a given model. Nevertheless mixing processes are described by a single amplitude and can be parameterized, without loss of generality, in terms of two parameters, which quantify the difference of the complex amplitude with respect to the SM one. Thus, for instance, in the case of  mixing we define  where  includes only the SM box diagrams, while  also includes the NP contributions. In the absence of NP effects,  and  by definition. In a similar way, one can write ![C_{\epsilon_K} = \frac{\mathrm{Im}[\langle
K^0|H_{\mathrm{eff}}^{\mathrm{full}}|\bar{K}^0\rangle]}
{\mathrm{Im}[\langle
K^0|H_{\mathrm{eff}}^{\mathrm{SM}}|\bar{K}^0\rangle]}\,,\qquad
C_{\Delta m_K} = \frac{\mathrm{Re}[\langle
K^0|H_{\mathrm{eff}}^{\mathrm{full}}|\bar{K}^0\rangle]}
{\mathrm{Re}[\langle
K^0|H_{\mathrm{eff}}^{\mathrm{SM}}|\bar{K}^0\rangle]}\,.
\label{eq:ceps}](/foswiki/pub/UTfit/ResultsWinter2011PostLP/_MathModePlugin_67ab6a9a7b559aa5224ab6e8d6c0ecab.png) Concerning  , to be conservative, we add to the short-distance contribution a possible long-distance one that varies with a uniform distribution between zero and the experimental value of  . The experimental quantities determined from the  mixings are related to their SM counterparts and the NP parameters by the following relations:  in a self-explanatory notation. All the measured observables can be written as a function of these NP parameters and the SM ones ? and ?, and additional parameters such as masses, form factors, and decay constants. Click on the parameter name to jump to the corresponding plot The fit results for all the nine CKM elements are  |
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r3 - 04 Mar 2012 - 16:18 - DenisDerkach |
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r2 - 04 Dec 2011 - 21:56 - DenisDerkach |
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