CP VIOLATION in b → s l + l - Transition. Direct CP-Violation . CP non-conservation shows up as a rate difference between two processes that are the CP conjugates of one-another. How can such a rate difference appear?.
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CP VIOLATION in b → s l+ l- Transition
CP non-conservation shows up as a rate difference between two processes that are the CP conjugates of one-another.
How can such a rate difference appear?
This shows that the effect will vanish if the two coupling constants can be made
relatively real. And also if strong phase be zero.
4 parameters :
Euler angles: ½ n(n-1)=3
Complex Phase: ½ (n-1)(n-2)=1
Unitarity and Properties of CKM
physics beyond the Standard Model will have, in general, possible additional CP-violating parameters. Any further fields, such as any additional Higgs fields, can introduce further CP-violating couplings. Such effects may then enter into B decay physics.
1 . As a test of SM and beyond SM
2. As a tool to Det. CKM elements
such as Vtq(q=d,s,b), Vub
3. CP- Violation
b → s l+ l-
Vub Vus* + Vtb Vts* + Vcb Vcs* = 0
Using unitary condition of CKM matrix and
neglecting |VubV*us| in comparison to
|VtbV*ts| and |VcbV*cs| Indicate that such decay involves only
CP –Violation in this channel is suppressedby SM.
We extend the matrix element of the
b → s l+ l- where C9get a new weak phase.
Minimal Extension of the SM:
ΛnewCan be parameterized as :
Using the expression of the matrix element and neglecting the s-quark mass(ms), we obtain the expression for the differential decay rate as:
∆ is expression in terms of masses , Wilson coefficients.
The differential decay width for the CP conjugated process can be obtain by making the replacements:
CP-asymmetry is evaluated to be
Since for any allowed region of s, << , So, we can ignore the term proportional to in the dominator of equation:
help us to get an idea about magnitude of new. We assume that:
In order to eliminate the sdependence, instead of CP asymmetry in the differential decay width, we study CP asymmetry in the total decay width by doing numerical integration over
sin ACP(s) equation:
The figure depicts that ACP is sensitive to the new weak phase and can reach about 4.5% which is quite measurable at future colliders such as LHCb, BTeV, ATLAS CMS or ILC .
In conclusion, this study has presented the CP asymmetry in the b → s l+ l- transition in
the minimal extension of the standard model where C9effreceived extra weak phase new due
to the new physics effects. We imposed 10% of uncertainty to the SM branching ratio of the
b → s l+ l- transition and obtained the bound on a new parameter new . Our predictive model
showed that the CP-violation asymmetry could reach to the order of 4.5% which was not only
entirely measurable in experiments, but also indicated the new physics effects, since in the
SM, this CP asymmetry is near zero.