Vincenzo Vagnoni on behalf of the Collaboration http
Vincenzo Vagnoni on behalf of the Collaboration http: //www. utfit. org 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. Bologna CP Violation, Rare decays, CKM ICHEP 06, Moscow, 27 th July 2006
The Unitarity Triangle The unitarity relations of the CKM matrix in the SM can be pictured as triangles in the complex plane Amongst several triangles, the so-called Unitarity Triangle has sides of comparable sizes O( 3) and is defined by Wolfenstein parametrization of the CKM 4 parameters: , A, , d s b u 1 - 2/2 A 3( -i ) c - 1 - 2/2 A 2 -A 2 1 t A 3(1 - -i ) Several measurements (over-)constrain in different ways the CKM parameters in the SM and need to be consistently combined in one fit Consistency of the fit allows to test the SM description of CPV see V. Vagnoni in the BST session for extended UT fits including New Physics quantities Vincenzo Vagnoni ICHEP 06, Moscow, 27 th July 2006
The UTfit method and the inputs Experimental CKM param. of the Theoretical Inputs measurements Inputs 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 . . Mr. Bayes For details see: UTfit Collaboration hep-ph/0501199 hep-ph/0509219 hep-ph/0605213 hep-ph/0606167 http: //www. utfit. org Joint probability density function for , ICHEP 06, Moscow, 27 th July 2006
Standard constraints for the SM analysis in the - plane levels @ 68% (95%) CL Vub/Vcb Pre-beauty factory era(-like) constraints K md/ ms Beauty factory era constraints sin(2 ) Vincenzo Vagnoni cos(2 ) ICHEP 06, Moscow, 27 th July 2006 4
from , , SU(2) analysis (neglecting EWP) for and Gronau, London Phys. Rev. Lett. 65, 3381– 3384 (1990) All combined unknowns observables Dalitz analysis for Snyder, Quinn Phys. Rev. D 48, 2139 -2144 (1993) Vincenzo Vagnoni ICHEP 06, Moscow, 27 th July 2006 5
Tree level determination of from B± D(*)0 K(*)± u W B - Interference if same D 0 and D 0 final states Favoured GLW (Gronau, London, Wyler) s b - K c Vcb D Uses CP eigenstates of D 0 decays 0 u u ADS (Atwood, Dunietz, Soni) Colour suppressed Vub = |Vub | e-i u b B - W c s u u D K 0 Dalitz Method – GGSZ analyze D 0 three-body decays on the Dalitz plane - strong amplitude (the same for Vub and Vcb mediated transitions strong phase difference between Vub and Vcb mediated transitions r. B is a crucial parameter - the sensitivity on depends on it Vincenzo Vagnoni ICHEP 06, Moscow, 27 th July 2006 Break-through of B-factories, but statistically limited and extremely challenging! 6
Tree level determination of from B± D(*)0 K(*)± (II) r. DK=0. 074± 0. 033 r. D*K=0. 059± 0. 043 r. DK*=0. 19± 0. 09 Combination of o o GLW+ADS+Dalitz methods = (78 ± 30) U (-102± 30) Error increased significantly with respect to previous estimates! r. B(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 Ba. Bar does not provide it yet Being this measurement basically NP-free, it is crucial to improve it if one wants to disentangle tiny NP effects Vincenzo Vagnoni ICHEP 06, Moscow, 27 th July 2006 7
cos 2 from B J/ K*0 and B D 0 0 u B J/ K*0 n u B D 0 0 n u an angular analysis allows to extract both sin 2 and cos 2 accessible by means of a Dalitz analysis of 3 -body D 0 decays analogously to the GGSZ method Statistically limited, but useful to remove the ambiguity from sin 2 , suppressing one of the two allowed bands n Non-SM solution excluded at 95% CL Vincenzo Vagnoni ICHEP 06, Moscow, 27 th July 2006 8
This year’s main novelty: ms measurement at CDF hep-ex/0606027 -1 ms = 17. 33 +0. 33 (stat. ) ± 0. 07 (syst. ) ps -0. 18 16. 96 ps-1 < ms < 17. 91 ps-1 (95% C. L. ) Prediction for ms in SM 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%. . . 13% error md/ ms md 5% error Vincenzo Vagnoni ICHEP 06, Moscow, 27 th July 2006 9
Pre-ICHEP 06 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 Vub= (3. 48 ± 0. 20) 10 -3 Prediction of UTfit without using Vub as input Vincenzo Vagnoni Combining Inclusive & exclusive Vub= (4. 20 ± 0. 20) 10 -3 ICHEP 06, Moscow, 27 th July 2006
Effect of the tension on indirect predictions: sin 2 Tension made evident by comparing the measurement of sin 2 with its indirect determination from the fit sin 2 =0. 791± 0. 034 from indirect determination sin 2 compatibility plots with Vub D L O put sin 2 =0. 687± 0. 032 in From direct measurement Vincenzo Vagnoni 2 ICHEP 06, Moscow, 27 th July 2006 without Vub O. K.
Tension sligthly reduced with Summer 06 updates on Vub (but still there) sin 2 weight in the fit is increased due to its reduced error and to the increase of the Vub error th i w AG d te HF Vub=(4. 09± 0. 25)10 -3 a s d nt e p g u re ra (incl. + excl. average) r ve u Error increased c a central value decreased with Vub ed t a d p u sin 2 =0. 675± 0. 026 From direct measurement (central value and error decreased) Vincenzo Vagnoni without Vub 1. 5 ICHEP 06, Moscow, 27 th July 2006 12
Fit results with angles vs sides+ K Precision on comparable due to the precise sin 2 measurement, while ms induces a smaller error on Crucial to improve measurements of the angles, in particular (tree level NP-free determination) Still imperfect agreement in due to sin 2 and Vub discrepancy Vincenzo Vagnoni = 0. 170 ± 0. 052 [0. 103, 0. 247] @ 95% = 0. 178 ± 0. 037 [0. 103, 0. 247] @ 95% = 0. 321 ± 0. 023 [0. 271, 0. 367] @ 95% = 0. 375 ± 0. 027 [0. 323, 0. 427] @ 95% ICHEP 06, Moscow, 27 th July 2006 13
= 0. 166 ± 0. 029 Fit results with all [0. 107, 0. 222] @ 95% Prob. contraints in Standard Model analysis = 0. 340 ± 0. 017 [0. 307, 0. 372] @ 95% Prob. Vincenzo Vagnoni ICHEP 06, Moscow, 27 th July 2006
Conclusions u No clean evidence of deviations from the Standard Model description is emerging so far n n u 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. . . sin 2 docet! Two of the existing sectors (at least) must be improved in order to test in deep the SM CKM picture n In order to fully exploit the great experimental precision of the md and ms measurements, improvements in the Lattice QCD computation of and the SU(3) breaking parameter are needed l see M. Bona at the Lattice session n NP-free quantities must improve in particular, in order to disentangle NP effects: l Vub/Vcb l from tree level decays l See V. Vagnoni in the BST session u We are most probably beyond the era of alternatives to the SM description of CP violation, and should instead look for corrections n u Need very precise measurements in the Bd and Bs sectors to spot out tiny effects (LHCb, Super. B? ) The bottle of champagne can still wait in the fridge another little bit. . . Vincenzo Vagnoni ICHEP 06, Moscow, 27 th July 2006 15
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