On the Flavor Problem in Strongly Coupled Theories - THEP Mainz
On the Flavor Problem in Strongly Coupled Theories - THEP Mainz
On the Flavor Problem in Strongly Coupled Theories - THEP Mainz
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2.5. Hierarchies <strong>in</strong> Quark Masses and Mix<strong>in</strong>gs and <strong>the</strong> RS GIM Mechanism 87<br />
with <strong>the</strong> overlap <strong>in</strong>tegrals<br />
(δq)ij = 2π<br />
� 1<br />
Lɛ ɛ<br />
(δQ)ij = 2π<br />
Lɛ<br />
� 1<br />
ɛ<br />
(∆g q<br />
h )ij = 2π<br />
� 1<br />
Lɛ ɛ<br />
dt a<br />
Q †<br />
i<br />
SQ<br />
q †<br />
dt ai Sq<br />
i (t)SQ j (t) aQ<br />
j<br />
i (t)Sq j<br />
(t) aq<br />
j<br />
q †<br />
dt δ(t − 1) ai Sq<br />
i (t)Y † q S Q<br />
j (t) aQ<br />
j . (2.179)<br />
The last <strong>in</strong>tegral corresponds to <strong>the</strong> second Yukawa coupl<strong>in</strong>g <strong>in</strong> (2.177) and must be<br />
evaluated with a properly regularized delta function, see [118, p.135f.]. It will represent<br />
<strong>the</strong> lead<strong>in</strong>g term <strong>in</strong> Higgs mediated flavor violat<strong>in</strong>g processes, because it is not chirally<br />
suppressed. However, for all processes considered it can still be neglected, because <strong>in</strong><br />
<strong>the</strong> case of ∆F = 1 currents <strong>the</strong> flavor-conserv<strong>in</strong>g vertex is chirally suppressed and for<br />
∆F = 2 currents it is smaller <strong>the</strong>n <strong>the</strong> tensor structure (2.176) by a factor v 2 /M 2 KK .<br />
It is however important <strong>in</strong> Higgs physics [127].<br />
In <strong>the</strong> ZMA, <strong>the</strong> above matrices simplify considerably,<br />
∆Q → U q†<br />
L diag<br />
�<br />
F 2 (cQi )<br />
�<br />
U<br />
3 + 2cQi<br />
q<br />
L ,<br />
∆q → U q†<br />
R diag<br />
�<br />
F 2 (cqi )<br />
�<br />
U<br />
3 + 2cqi<br />
q<br />
R ,<br />
∆ ′ Q → U q†<br />
L diag<br />
�<br />
5 + 2cQi<br />
and<br />
where<br />
� �<br />
�∆Q<br />
mn⊗ � ∆q<br />
� ′<br />
�<br />
∆ ′ q → U q†<br />
R diag<br />
m ′ n ′ → �<br />
i,j<br />
� q† �<br />
UL mi<br />
( � ∆Qq)ij = F 2 (cQi )<br />
3 + 2cQi<br />
2(3 + 2cQi )2 F 2 (cQi )<br />
�<br />
5 + 2cqi<br />
2(3 + 2cqi )2 F 2 (cqi )<br />
�<br />
� q�<br />
UL <strong>in</strong> ( � ∆Qq)ij<br />
�<br />
U q<br />
L ,<br />
U q<br />
R , (2.180)<br />
� q† �<br />
UR m ′ j<br />
� q �<br />
UR jn ′ , (2.181)<br />
3 + cQi + cqj F<br />
2(2 + cQi + cqj )<br />
2 (cqj )<br />
, (2.182)<br />
3 + 2cqj<br />
and analogue for <strong>the</strong> rema<strong>in</strong><strong>in</strong>g comb<strong>in</strong>ations of <strong>in</strong>dices Q and q. Because of <strong>the</strong><br />
v/MKK suppression <strong>in</strong> (2.150), <strong>the</strong> ε structures vanish <strong>in</strong> <strong>the</strong> ZMA. Us<strong>in</strong>g <strong>the</strong> fact that<br />
all ci parameters except cu3 are very close to −1/2, it is a reasonable approximation<br />
to replace (3 + cQi + cqj )/(2 + cQi + cqj ) by 2, <strong>in</strong> which case we obta<strong>in</strong> <strong>the</strong> approximate<br />
result<br />
�∆A ⊗ � ∆B → ∆A ∆B , (2.183)