Charmless Hadronic BPP decays in the context of SU3 symmetry

1
Charmless Hadronic B?PP decays in the context of
SU(3) symmetry

• Denis Suprun
• Brookhaven National Lab

2
Motivation

• B factories have produced a lot of excitement,
  particularly in measuring indirect
  (mixing-induced) CPV in the B system
• sin2ß0.6850.032
• from B?yKS based upon BaBars and Belles data
  (LP05)
• era of precision measurement
• We also want to observe direct CPV in B system
  and to check whether it is consistent with SM
  expectation
• BaBar and Belle announced first observation of
  direct CPV
• ACP(p-K) -0.114 ? 0.018
• Most branching ratios of charmless B ? PP and PV
  are currently measured with errors about 10,
• i.e. 5 errors in amplitude

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Charmless B decays

• Relatively rare decays with branching ratios of
  the order 10-5
• Wealth of new increasingly precise measurements
• Many of them involve interference of a tree and a
  penguin amplitude with a weak phase ? between
  them
• Nonzero (mod p) strong phases are required for CP
  Violation
• Are well suited to
• constrain ?
• determine the magnitude of penguin contributions
• get information on strong phases

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CKM Matrix and Unitarity Triangle
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CKM Matrix and B Physics

• Many B decays involve the two CKM elements of
  interest to us and may reveal CP violating
  effects
• The ultimate goal of studies in B physics is not
  only to achieve precision measurements of the
  above parameters, but to discover New Physics
• One way to detect New Physics is to perform
  consistency checks for the sizes and phases of
  the CKM elements

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CKM Fitter and UT Fit results
CKM Fitter, indirect ?(597-13)o
UT Fit, indirect ?(57.97.3)o
Direct measurements ?(6315-12)o
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B ?PP decays
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Dominant types of amplitudes
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Assumptions

• Neglect E, A, PA
• SU(3) flavor symmetry
• The only deviation from SU(3) is through decay
  constants in tree diagrams
• SU(3) is implied when we assume
• the same phases for T and T?
• that QCD and EW penguins P? and P and
  color-suppressed amplitudes C? and C are related
  to each other as the ratio of the involved CKM
  parameters
• that a penguin in which a gluon couples to
  has the same amplitude as those that couple to
  and

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Approach

• Take all available information on charmless B
  decays to a PP final state and fit it with a
  simple model of interference between appropriate
  tree and penguin diagrams
• Extract magnitudes and relative phases of tree
  and penguin amplitudes
• Predict branching ratios and CP asymmetries for
  observed and as-yet-unseen modes
• Considerable sensitivity to ?.

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Data, Parameters and Results of pp, KK, Kp Fit

• 19 branching ratios and CP asymmetries in
• strangeness-preserving pp, KK decays (?S0)
• strangeness-changing Kp decays (?S1)
• direct and mixing-induced asymmetries in pp- and
  p0KS decays
• 8 fit parameters
• weak phase ?
• amplitudes T, C, P?, Ptu
• strong phases dT , dC , dPtu
• RESULTS
• Fit ?215.5/11 ?(43122)o
• Reasonable C/T0.450.130.01
• Large dC-66o , indication of final state
  interactions

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Data and Parameters and Results of the Full PP
Fit

• 30 data points
• branching ratios and CP asymmetries in
• strangeness-preserving pp, KK, p?, p?? decays
  (?S0)
• strangeness-changing Kp, K?, K?? decays (?S1)
• direct and mixing-induced asymmetries in pp-,
  p0KS and ??KS decays
• 12 fit parameters
• weak phase ?
• amplitudes T, C, P?, Ptu, S?, Stu
• strong phases dT , dC , dPtu , dS , dStu
• RESULTS
• Fit ?226.2/18 ?(6092)o

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Comments on SU(3) and other assumptions

• In the last year new and more precise PP
  measurements shifted closer to our predictions.
• Used to say
• Despite smaller errors the quality of the fit
  improved from 32 to 41 to 51. Fit parameters
  remained stable.
• We can not yet see significant SU(3) breaking
  effects or the presence of the E, A, or PA
  amplitudes in the current PP data.
• Now
• No longer true. SU(3) fit quality after LP05 is
  16.
• Perhaps, our assumptions of SU(3) or negligible
  E,A,PA are close to being inadequate for the
  current precision of the experimental data.

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Summary of SU(3) fits

• Flavor symmetry is employed to analyze B decays
  into PP final states symmetry breaking effect is
  partially taken into account through the ratio of
  tree amplitudes.
• Flavor SU(3) generally fits data well, with some
  exceptions. Predictions are made based upon
  current measurements.
• Our preferred ?(6092)o fit in PP modes favors
  a weak phase g within the range 51o-69o at 1s
  level. It is also compatible with the indirect
  constraints on g 46olt?lt66o
• Indications of substantial A, E, PA amplitudes
  or SU(3) breaking effects