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Bologna

Vincenzo Vagnoni. on behalf of the Collaboration http://www.utfit.org. Bologna. M. Bona, M. Ciuchini, E. Franco, V. Lubicz, G. Martinelli, F. Parodi, M. Pierini, P. Roudeau, C. Schiavi, L. Silvestrini, V. Sordini, A. Stocchi, V. V. CP Violation, Rare decays, CKM. The Unitarity Triangle.

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Bologna

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  1. Vincenzo Vagnoni on behalf of the Collaborationhttp://www.utfit.org Bologna M. Bona, M. Ciuchini, E. Franco, V. Lubicz,G. Martinelli, F. Parodi, M. Pierini, P. Roudeau,C. Schiavi, L. Silvestrini, V. Sordini, A. Stocchi, V. V. CP Violation, Rare decays, CKM

  2. The Unitarity Triangle d s b u l A l3(r-ih) 1-l2/2 c -l 1-l2/2 Al2 t A l3(1-r-ih) -Al2 1 The unitarity relations of the CKM matrixin the SM can be pictured as trianglesin the complex plane Amongst several triangles, the so-called Unitarity Triangle has sides ofcomparable sizes O(3) and is defined by Wolfenstein parametrization of the CKM 4 parameters:l,A, r, h Several measurements (over-)constrain indifferent ways the CKM parameters in the SMand need to be consistently combined in one fit Consistency of the fit allows to testthe SM description of CPV see V. Vagnoni in the BST session for extended UT fits including New Physics quantities

  3. The UTfit method and the inputs Experimental Inputs CKM param. of the measurements TheoreticalInputs Standard Model + OPE, HQET, Lattice QCD from quarks to hadrons  see M. Bona in the Lattice session for the impact and importance of Lattice QCD in UT fits ... ... ... For details see:UTfit Collaborationhep-ph/0501199hep-ph/0509219hep-ph/0605213hep-ph/0606167http://www.utfit.org Mr. Bayes Joint probability density function for , 

  4. Standard constraints for the SM analysis in the r-h plane levels @ 68% (95%) CL Pre-beauty factory era(-like) constraints eK Dmd Vub/Vcb Dmd/Dms Beauty factory era constraints   sin(2b) cos(2b)

  5.  from , ,  SU(2) analysis (neglecting EWP) for  and  All combined Gronau, LondonPhys. Rev. Lett. 65, 3381–3384 (1990) unknowns observables Dalitz analysis for  Snyder, QuinnPhys.Rev.D48,2139-2144 (1993)

  6. K- s l W b c Vcb B- u c u u u Vub = |Vub | e-ig u D 0 b B- W s K- u Tree level determination of  from B±D(*)0K(*)± Interference if same D0 and D0 final states Favoured GLW (Gronau,London,Wyler) Uses CP eigenstates of D0 decays D0 ADS (Atwood, Dunietz, Soni) Colour suppressed Dalitz Method – GGSZanalyze D0 three-body decayson the Dalitz plane strong amplitude (the same for Vub and Vcb mediated transitions Break-through ofB-factories, but statistically limited and extremely challenging! strong phase difference between Vub and Vcb mediated transitions rB is a crucial parameter - the sensitivity on depends on it

  7. Tree level determination of  from B±D(*)0K(*)±(II) rDK*=0.19±0.09 rDK=0.074±0.033 rD*K=0.059±0.043 Combination of GLW+ADS+Dalitz methods  = (78 ± 30)o U (-102±30)o Error increased significantly with respect to previous estimates! rB(D*K) smaller, effect of D*K less relevant but dominant effect comes from the Dalitz model we now use the full covariance matrix provided by Belle to account for the error on the Dalitz model since BaBar does not provide it yetBeing this measurement basically NP-free, it is crucial to improve it if one wants to disentangle tiny NP effects

  8. cos2 from BJ/K*0 and BD00 • BJ/K*0 • an angular analysis allows to extract both sin2 and cos2 • BD00 •  accessible by means of a Dalitz analysis of 3-body D0 decays analogously to the GGSZ method • Statistically limited, but useful to remove the ambiguityfrom sin2, suppressing one of the two allowed bands • Non-SM solution excluded at 95% CL

  9. This year’s main novelty: ms measurement at CDF hep-ex/0606027 ms = 17.33 +0.33 (stat.) ± 0.07 (syst.) ps-1 -0.18 16.96 ps-1 < ms < 17.91 ps-1 (95% C.L.) Prediction for ms inSM UT fits without using the measurement as input ms = 19.0 ± 2.4 ps-1 [14.7, 24.2] ps-1 at 95% Experimental measurement much more precise than indirect determination extremely powerful constraint in SM analysis - improvements in Lattice QCD involved parameters would be important to fully exploit md & ms measurements nowadays known at about 1%... Dmd/Dms Dmd 13% error 5% error

  10. Pre-ICHEP06 situation: tension in the fit due to excessive Vub inclusive NP free measurement of Vub vs NP sensitive indirect determination Vub= (3.80 ± 0.27 ± 0.47) 10-3 exclusive from HFAG value of experimental BR + quenched LQCD O.K. 3 Vub= (4.38 ± 0.19 ± 0.27) 10-3 from inclusive determination (HFAG average) x 2.5 Combining Inclusive & exclusive Vub= (4.20 ± 0.20) 10-3 Vub= (3.48 ± 0.20) 10-3 Prediction of UTfit without using Vub as input

  11. Effect of the tension on indirect predictions: sin2 Tension made evident by comparing the measurement of sin2 with its indirect determination from the fit sin2 =0.791±0.034 from indirect determination sin2 compatibility plots with Vub without Vub 2 O.K. OLD input sin2=0.687±0.032 From direct measurement

  12. Tension sligthly reduced with Summer 06 updates on Vub (but still there) Vub=(4.09±0.25)10-3 (incl. + excl. average) Error increased central value decreased updated with current HFAG averages sin2 weight in the fit is increased due to its reduced error and to the increase of the Vub error with Vub without Vub updated sin2=0.675±0.026 From direct measurement (central value and error decreased) 1.5

  13. Fit results with angles vs sides+K Precision on  comparable due to the precise sin2 measurement, while ms induces a smaller error on  Crucial to improve measurements of the angles, in particular  (tree level NP-free determination)  = 0.170 ± 0.052 [0.103, 0.247] @ 95%  = 0.178 ± 0.037 [0.103, 0.247] @ 95% Still imperfect agreement in  due to sin2 and Vub discrepancy  = 0.321 ± 0.023 [0.271, 0.367] @ 95%  = 0.375 ± 0.027 [0.323, 0.427] @ 95%

  14. Fit results with allcontraints inStandard Model analysis  = 0.166 ± 0.029 [0.107, 0.222] @ 95% Prob.  = 0.340 ± 0.017 [0.307, 0.372] @ 95% Prob.

  15. Conclusions • No clean evidence of deviations from the Standard Model description is emerging so far • Slight discrepancies due to an excess in Vub inclusive, but insufficient to claim for significant hints that something is wrong in the SM • However, if SM picture is correct, Vub should go down to ~3.5·10-3 sooner or later... sin2 docet! • Two of the existing sectors (at least) must be improved in order to test in deep the SM CKM picture • In order to fully exploit the great experimental precision of the mdand ms measurements, improvements in the Lattice QCD computation of and the SU(3) breaking parameter  are needed • see M. Bona at the Lattice session • NP-free quantities must improve in particular, in order to disentangle NP effects: • Vub/Vcb •  from tree level decays • See V. Vagnoni in the BST session • We are most probably beyond the era of alternatives to the SM description of CP violation, and should instead look for corrections • Need very precise measurements in the Bd and Bs sectors to spot out tiny effects (LHCb, SuperB?) • The bottle of champagne can still wait in the fridge another little bit...

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