1. CKM Status
In this lecture, we study the results summarized in this plot.
November 17, 2018
Sridhara Dasu, CKM Status

2. Quark Mixing : Unitarity
In Standard Model CP violation is due to single non-zero complex phase of this matrix
Agreement amongst various measurements of angles and sides is crucial test of the Standard Model
All but DMs (CDF/D0) are accessible to BaBar b a g
B  y K
Clean experiment/theory
|Vtd / Vts|
Bd,s mixing: DMd / DMs
|Vub / Vcb|
b  u l n / b  c l n
November 17, 2018
Sridhara Dasu, CKM Status

3. The Standard Model CKM Matrix
Complex matrix described by 3 real parameters + 1 complex phase
Wolfenstein parameterization:
Exploit hierarchy in magnitudes by using Cabibbo angle, l=sinqc
A, r, h are O(1)
CP Violation:
November 17, 2018
Sridhara Dasu, CKM Status

4. Sridhara Dasu, CKM Status
Unitarity Triangle
Choice of parameters: a Rt Ru g b
November 17, 2018
Sridhara Dasu, CKM Status

5. Weak B Decays - Access to CKM Parameters
s,d
W - t b g
Rare Effective FCNC
November 17, 2018
Sridhara Dasu, CKM Status

6. Sridhara Dasu, CKM Status
B Mixing
Neutral B mesons can turn into their anti-particle
November 17, 2018
Sridhara Dasu, CKM Status

7. B Mass & Lifetime Difference
Second order weak diagram gives non-zero matrix element
In basis have a non-diagonal Hamiltonian
Recall Eigenstates are:
Unlike the case of neutral K mesons, for B mesons M is significant but  is negligible.
November 17, 2018
Sridhara Dasu, CKM Status

8. Sridhara Dasu, CKM Status
B Mixing
Neutral B mesons can turn into their anti-particle
In SM described by “box diagrams” measure |Vts(d)|
 ms(d) = [GF2mt2 F(mt2/mW2)/62] mBs(d)f2Bs(d)BBs(d)|Vts(d)V*tb|2
Oscill. Freq.
~ 1
From lattice
O(30%) error
November 17, 2018
Sridhara Dasu, CKM Status

9. Sridhara Dasu, CKM Status
Bd & Bs Mixing
Measurement of yields measurement of UT side
with O(5%) theory error
November 17, 2018
Sridhara Dasu, CKM Status

10. Sridhara Dasu, CKM Status
The Golden Channel
November 17, 2018
Sridhara Dasu, CKM Status

11. Time Dependent Measurements
November 17, 2018
Sridhara Dasu, CKM Status

12. Sridhara Dasu, CKM Status
The SLAC B-Factory
Design Luminosity: 3 x 1033 cm-2 s-1 (Reached in 2001)
Peak Luminosity: 9 x 1033 cm-2 s-1 (Reached in 2004)
November 17, 2018
Sridhara Dasu, CKM Status

13. Sridhara Dasu, CKM Status
e+ e–  b b
Signal:
Continuum background:
cont : B ~ 4.3 : 1
November 17, 2018
Sridhara Dasu, CKM Status

14. Sridhara Dasu, CKM Status
BaBar
g, p0 and e± ID
p/K/p ID
Charged Particle Tracking, Vertex Reconstruction (Dt), Low momentum particle ID dE/dx
m and KL ID
RPC problems overcome
Forward RPCs replaced (2002)
Barrel RPCs  LSTs (2004/6)
November 17, 2018
Sridhara Dasu, CKM Status

15. Four Main Themes in B Physics
CP Violation in B decays
Due to interference of mixing and decay amplitudes (indirect)
Due to decay amplitude interference (direct)
Searches for and studies of rare decays
Sensitive to physics beyond the Standard Model
B decay rate to rare final states
CP violation of rare decays - can be very sensitive
Precision determination of CKM matrix elements
Need to significantly improve in order to determine whether observed CP violation is consistent with SM predictions
Improving our understanding of B decays
Feeds back into precision SM tests and measurements
November 17, 2018
Sridhara Dasu, CKM Status

16. Sridhara Dasu, CKM Status
Sin2b Measurement
BABAR
BABAR
Update for ICHEP04
BABAR PUB-04/038
November 17, 2018
Sridhara Dasu, CKM Status

17. Sridhara Dasu, CKM Status
sin2 Comparison
CP violation in B system is almost consistent with Standard Model expectations
Comparison of Tree and Gluonic penguin dominated decays provide new physics sensitivity
Curiously gluonic penguin results are systematically low
More data is needed to resolve experimental discrepancies
Do electroweak penguin modes have anything to say?
November 17, 2018
Sridhara Dasu, CKM Status

18. Electromagnetic Penguin
B-meson mass
B-quark mass
b-quark Fermi momentum
s,d
Vts,Vtd
u,d
W - t b g
Penguins used for measuring Vtd
November 17, 2018
Sridhara Dasu, CKM Status

19. Sridhara Dasu, CKM Status
Photon Spectrum
Sum of exclusive method
Lepton tagged inclusive
preliminary
K*
K*
(4s) frame
B rest frame
November 17, 2018
Sridhara Dasu, CKM Status

20. Sridhara Dasu, CKM Status
Moments of  Spectrum
B-meson mass
B-quark mass
b-quark Fermi momentum
First, Second moments of Eg
hep-ex/
First and second moments of the photon spectrum are used in heavy quark effective theory models.
November 17, 2018
Sridhara Dasu, CKM Status

21. Sridhara Dasu, CKM Status
Shape Function
HQ parametersdetermine shape function for Vub extraction
Fit to the Eg spectrum in bsg – Belle+Babar
Fit to the Eg moments of Eg spectrum - Babar
Had and lept. moments in bcln – Babar+others
Fit to all moments
Fit to bcln moments
Fit to b—sg moments
Belle b—sg spectrum fit
|Vcb| : moments analyses have 1.5–2% precision!
CKM-05
November 17, 2018
Sridhara Dasu, CKM Status

22. |Vub |
The extraction of |Vub|from the measured partial BFs is not trivial
Inclusive decays depend on measured shape function and OPE
Average of Inclusive Determinations of |Vub|
free quark decay
nonperturbative
corrections
Method
Vub(10-3)
Inclusive, bcln & bsg moments
Inclusive, Belle only bsg spectrum
Indirectly, from CKM fit
More work needed to resolve discrepancies
November 17, 2018
Sridhara Dasu, CKM Status

23. Standard Model Unitarity
Tree Level sin2b
Consistent with SM
Progress requires
Measurements of a, g
Penguin pollution
Further checks of sin2b
Measure in penguins
Measurement of sides
Vub, Vtd
Rare processes
Hadronic uncertainty
HeavyLight form factor calculation
Radiative penguins are beginning to play an important role in constraining SM unitarity
November 17, 2018
Sridhara Dasu, CKM Status

24. Sridhara Dasu, CKM Status
Two Lifetimes
CP-odd fraction ( ) ~ 22%
+ Recent D0:
November 17, 2018
Sridhara Dasu, CKM Status