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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2.6. Four Fermion Interactions 89<br />
<strong>in</strong>duced <strong>in</strong>teractions aris<strong>in</strong>g from <strong>the</strong> exchange of a Z-boson read<br />
H (Z) 4πα<br />
eff =<br />
s2 wc2 w m2 �<br />
1 +<br />
Z<br />
m2 Z<br />
2M 2 �<br />
1 −<br />
KK<br />
1<br />
�<br />
m4 Z + O<br />
2L M 4 ���<br />
(2.186)<br />
KK<br />
× �<br />
S(¯qi, qj; ¯q ′ k , q′ l ) � ¯qLγ µ T q<br />
3 (1 − δQ)qL + ¯qRγ µ T q<br />
3 δqqR − s 2 w Qq ¯qγ µ q �<br />
q,q ′<br />
+ 4παL<br />
�<br />
�<br />
×<br />
+<br />
s 2 wc 2 w M 2 KK<br />
�<br />
q,q ′<br />
�<br />
× ¯q ′ LγµT q′<br />
3 (1 − δQ ′)q′ L + ¯q ′ RγµT q′<br />
3 δq ′q′ R − s 2 w Qq ′ ¯q′ γµq ′�<br />
S(¯qi, qj; ¯q ′ k , q′ l )<br />
�<br />
− ¯qLγµT q<br />
3 (1 − δQ)qL + ¯qRγµT q<br />
3 δqqR − s 2 �<br />
w Qq ¯qγµq<br />
¯q ′ Lγ µ T q′<br />
3 (∆Q ′ − εQ ′)q′ L + ¯q ′ Rγ µ T q′<br />
3 εq ′q′ R − s 2 w Qq ′<br />
�<br />
¯qLγ µ T q<br />
3 ( � ∆Q − �εQ)qL + ¯qRγ µ T q<br />
3 �εqqR − s 2 w Qq<br />
� ′<br />
¯q Lγ µ ∆Q ′q′ L + ¯q ′ Rγ µ ∆q ′q′ �<br />
R<br />
�<br />
�<br />
¯qLγ µ � ∆QqL + ¯qRγ µ � ∆qqR<br />
�<br />
⊗ ¯q ′ LγµT q′<br />
3 ( � ∆Q ′ − �εQ ′)q′ L + ¯q ′ RγµT q′<br />
3 �εq ′q′ R − s 2 w Qq ′<br />
�<br />
¯q ′ Lγµ � ∆Q ′q′ L + ¯q ′ Rγµ � ∆q ′q′ � �<br />
R<br />
�<br />
.<br />
Here, <strong>the</strong> δ and ε matrices appear due to <strong>the</strong> non-vectorial coupl<strong>in</strong>g of <strong>the</strong> Z. Also,<br />
by writ<strong>in</strong>g mZ, we implicitly assume <strong>the</strong> RS corrections (2.111) to be absorbed. Here<br />
and <strong>in</strong> <strong>the</strong> follow<strong>in</strong>g, mW,Z ≡ mRS . To a good approximation one can neglect <strong>the</strong>se<br />
W,Z<br />
terms and ends up with a considerably simpler expression, which holds up to order<br />
v4 /M 4 KK corrections,<br />
H (Z)<br />
eqq = 4πα<br />
s2 wc2 w m2 �<br />
1 +<br />
Z<br />
m2 Z<br />
<strong>in</strong> which<br />
− 8πα<br />
s 2 wc 2 w m 2 Z<br />
− 4παL<br />
s 2 wc 2 w M 2 KK<br />
�<br />
q<br />
2M 2 KK<br />
�<br />
q<br />
+ 4παL<br />
s2 wc2 w M 2 �<br />
KK q,q ′<br />
S(¯q, q; ¯q ′ , q ′ )<br />
J µ<br />
Z<br />
�<br />
1 − 1<br />
�<br />
m4 Z + O<br />
2L M 4 ���<br />
S(¯q, q; ¯q<br />
KK<br />
′ , q ′ )J µ<br />
Z JZµ<br />
S(¯qi, qj; ¯q ′ k , q′ l ) [¯qLγ µ T q<br />
3 δQqL − ¯qRγ µ T q<br />
3 δqqR] JZµ<br />
≡ �<br />
q<br />
� �<br />
(2.187)<br />
S(¯q, q; ¯q ′ , q ′ � �T q<br />
) 3 − s2 �<br />
w Qq ¯qLγ µ ∆QqL − s 2 w Qq ¯qRγ µ �<br />
∆qqR JZµ<br />
� � �T q<br />
3 − s2 w Qq<br />
� ¯qLγ µ � ∆QqL − s 2 w Qq ¯qRγ µ � ∆qqR<br />
� �<br />
⊗ T q′<br />
3 − s2w Qq ′<br />
�<br />
¯q ′ Lγµ � ∆Q ′q′ L − s 2 w Qq ′ ¯q′ Rγµ � ∆q ′q′ �<br />
R<br />
�<br />
,<br />
�� q<br />
T3 − s2 �<br />
w Qq ¯qLγ µ qL − s 2 w Qq ¯qRγ µ �<br />
qR . (2.188)<br />
�