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A Mathematica based Version of the CKMfitter Package

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50 Chapter 6. New Physics Beyond <strong>the</strong> Standard Model<br />

<strong>the</strong>ory predictions <strong>of</strong> <strong>the</strong> relevant observables are changed as follows [67]:<br />

γ ⇒ γ (tree level dominated)<br />

|Vud|, |Vus| ⇒ |Vud|, |Vus| (tree level dominated)<br />

|Vub|, |Vcb| ⇒ |Vub|, |Vcb| (tree level dominated)<br />

∆md ⇒ ∆m NP<br />

d<br />

sin 2β ⇒ sin(2β + 2ϑd)<br />

= ∆mSM d · r 2 d<br />

cos 2β ⇒ cos(2β + 2ϑd) (6.2)<br />

α (= π − β − γ) ⇒ α NP (= π − β − γ − ϑd)<br />

� �SM Γ12 sin 2ϑd<br />

ASL ⇒ A NP<br />

SL = −Re<br />

M12<br />

r 2 d<br />

� �SM Γ12 cos 2ϑd<br />

+ Im<br />

M12 r2 d<br />

The tree-level dominated constraints from |Vud|, |Vus|, |Vub|, |Vcb| and γ remain unchanged.<br />

The o<strong>the</strong>r observables in Eqn. 6.2 have more important loop contributions<br />

which are sensitive to possible New Physics effects. The only constraint on both NP<br />

parameters r 2 d and 2ϑd comes from <strong>the</strong> semileptonic CP asymmetry ASL, where <strong>the</strong><br />

SM prediction <strong>of</strong> Γ12/M12 is used here at LO in QCD.<br />

The observables in Eqn. 6.2 provide significant constraints in <strong>the</strong> (¯ρ,¯η) plane as well<br />

as in <strong>the</strong> (r 2 d ,2ϑd) plane. The results <strong>of</strong> a global New Physics fit are shown in <strong>the</strong><br />

Figures 6.1 to 6.5, where <strong>the</strong> used input values are summarized in Table 5.1 & 5.2.<br />

η<br />

1.5<br />

1<br />

0.5<br />

0<br />

-0.5<br />

-1<br />

γ<br />

α<br />

-1.5<br />

-1 -0.5 0 0.5 1 1.5 2<br />

ρ<br />

β<br />

CKM<br />

1-CL<br />

f i t t e r<br />

ICHEP 2006<br />

1<br />

0.9<br />

0.8<br />

0.7<br />

0.6<br />

0.5<br />

0.4<br />

0.3<br />

0.2<br />

0.1<br />

0<br />

(rad)<br />

d<br />

2 ϑ<br />

3<br />

2<br />

1<br />

0<br />

-1<br />

-2<br />

CKM<br />

1-CL<br />

f i t t e r<br />

ICHEP 2006<br />

-3<br />

0 1 2 3<br />

r 2<br />

d<br />

4 5 6<br />

Figure 6.1: Constraints within <strong>the</strong> framework <strong>of</strong> New Physics contributions to <strong>the</strong> B 0 - ¯ B 0<br />

mixing amplitude on <strong>the</strong> (¯ρ,¯η) plane (left) and on <strong>the</strong> (r 2 d ,2ϑd) plane (right), obtained from<br />

a global CKM fit including |Vud|, |Vus|, |Vub|, |Vcb|, ∆md and sin 2β.<br />

Figure 6.1 shows <strong>the</strong> confidence level obtained from a global CKM fit in <strong>the</strong> (¯ρ,¯η)<br />

and (r 2 d ,2ϑd) planes, assuming New Physics contributions to B 0 - ¯ B 0 oscillations.<br />

1<br />

0.9<br />

0.8<br />

0.7<br />

0.6<br />

0.5<br />

0.4<br />

0.3<br />

0.2<br />

0.1<br />

0<br />

.

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