(BABAR Collaboration) LAL – Orsay (Marie Curie EIF) A. Oyanguren (BABAR Collaboration) LAL – Orsay (Marie Curie EIF) 3/11/05 - Physikalisches Institut, Universität Bonn

Outline  The CKM matrix  Semileptonic decays of b quarks  Exclusive |Vcb|  Inclusive |Vcb|  Moment analysis  D** states  Semileptonic decays of c quarks  Calibrating Lattice-QCD  Summary 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 2

Vud Vus Vub Vcd Vcs Vcb Vtd Vts Vtb The CKM matrix Weak interactions of quarks in the SM:  The CKM matrix: Vud Vus Vub Vcd Vcs Vcb Vtd Vts Vtb VCKM = mq + Vqq’  10 fundamental parameters of the Standard Model 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 3

The goal: Understand the SM picture The CKM matrix In the SM: VCKM unitary  4 free parameters Vud Vus Vub Vcd Vcs Vcb Vtd Vts Vtb VCKM =  Wolfenstein Parameterization l = |Vus| = 0.2227  0.0017 1-l2/2+O(l4) l A l3(r-ih) VCKM ~ -l+O(l5) 1-l2/2+O(l4) Al2 Al3(1-r-ih)+O(l5) -Al2+O(l4) 1+O(l4) The goal: Understand the SM picture to be able to find New Physics signatures 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 4

The Unitarity Triangle (UT) * VudVub* + VcdVcb* + VtdVtb* =0 Vud Vus Vub Vcd Vcs Vcb Vtd Vts Vtb Vud Vcd Vtd Vus Vcs Vts Vub Vcb Vtb = The unitary clock (r,)  a g b (0,0) (1,0) The idea: Overconstrain the UT Vcb and Vub have a key role  determined from tree level processes Other approaches: http://www.slac.stanford.edu/xorg/ckmfitter 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 5

The problem The problem: quarks are confined inside hadrons... Instead of : Vcb We deal with : Vcb 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 6

l sl = |Vxx’|2 f (theory) Vxx’ The theoretical tools nl q2 x X’ Exclusive processes: Inclusive processes: 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 7

The theoretical tools Exclusive processes: Vcd Parameterized by form factors Heavy Quark Effective Theory For heavy quarks  expansions in 1/mQ  flavour and spin symmetries  relations between form factors Lattice-QCD QCD computations  form factor calculations Difficult to put quarks of different mass in the lattice  Need calibration 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 8

Operator Product Expansion The theoretical tools Inclusive processes: for heavy quarks  Operator Product Expansion = x Vcb f( parameters related with b quark properties inside the hadron )  kinetic energy, spin... Measurement of moments: Some inclusive observables  O  depend on the same parameters (For instance: HbHc : the lepton energy, the mass distribution of HC ) Same parameters for bc and bu transitions 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 9

Measuring Vcb 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 10

The experiments (4S) BB Z  bb BABAR PB~ 30GeV BELLE PB~ 1GeV DELPHI CLEO (III) CLEO OPAL ALEPH Z  bb PB~ 0.3GeV 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 11

Exclusive measurement of |Vcb| Known function Form factor of the B D* transition FD*(1)=1  Normalized by HQET (mQ  ) at q2max   FD*(1)= 0.91  0.04  (1/ mQ )n and QCD corrections   The shape parameterized with a form factor slope  2 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 12

Exclusive measurement of |Vcb| m= m(D0) -m(D0) ~ m(soft) D*+ - l- candidates Eur. Phys. J. C33 (2004) 213 B  D* l -  D0 soft m= m(D0) -m(D0) ~ m(soft) D0  K-+ D0  K- + - + D0  K-+(0) 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 13

Exclusive measurement of |Vcb| World average |Vcb|=0.0413  0.0010  0.0020 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 14

Inclusive measurement of |Vcb| sl incl = B (BXcln)/B = |Vcb|2 f ( ) B = 1.568  0.009 ps d|Vcb| |Vcb| < 1% B (BXcln) = (10.70 0.14)% Need the same accuracy in f ( )  Ex: Studying the Xc hadronic mass distribution Getting these parameters from other observables: What is Xc? 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 15

? The hadronic system Xc HQET: D* 52% D 21% D**  27% Ground states Broad states Narrow states 21% 52%  27% ? D D* D** 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 16

D** mass distribution Exclusive reconstruction of Right sign Wrong sign ALEPH [ZP C73 (97) 601] D(*)pp contributions Right sign Found < 0.22% Wrong sign 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 17

D** mass distribution DELPHI fit superimposed to CDF data considering B(D1,D*1 Dpp =(2015)% [PRD 71 (05) 051103] CERN-EP-PH-2005-015 Narrow states B D1= (0.56 0.10)% (constrained) B D*2= (0.30 0.08)% Broad states B D*1= (1.24  0.25  0.27)% mD*1= 2445  34  10 MeV D*1= 234  74  25 MeV B D*0= (0.42  0.33 0.22)% D*0= 260  130  130 MeV BNR= (0.23  0.35  0.44)% sNR= (5.0  7.0) (GeV/c2)-1 (CDF normalized to the # DELPHI entries) 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 18

|Vcb| from Moments + G rLS Moments of the hadronic mass distribution Moments of the lepton energy spectrum 2 G 3 rLS Fixing ( ~ MB*-MB ) , and using constraints on mb and mc 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 19

|Vcb| from Moments OPE parameters from DELPHI Phys.Lett. B556 (2003) 41 LEP B(BXcln) OPE parameters from DELPHI Theo. uncertainty 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 20

|Vcb| from Moments The big success of OPE (hep-ph/0507253) 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 21

B (B narrow (jq=3/2) ln) >> B (B broad (jq=1/2) ln) Something puzzeling Theoretical predictions (OPE values, sum rules, lattice QCD) B (B narrow (jq=3/2) ln) >> B (B broad (jq=1/2) ln) B (B0Xcln) - B (B0Dln) - B (B0D*ln) = (2.9  0.3)% B (B0 D**ln) = (2.7  0.7  0.2)% With narrow states only accounting for (0.86  0.13) % B (B narrow ln) < B (B broad ln) Measured broad component not (only) jq=1/2? ( 0’, L>1 states?) Large 1/mc contributions in the theoretical predictions? 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 22

Decays of c quarks 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 23

Computations need to be confronted with experimental results Lattice-QCD d QCD computations in a space-time lattice parameters: s and quark masses a matrix elements: decay constants, form factors... Current Lattice-computers ~ teraflop = 1012 operations/sec. Difficult to put together quarks of very different mass  approximations Difficult to include dynamical quark-pairs  unquenched Impressive accurate results Ex: new result of fB = 216  22 MeV (HPQCD) affecting md  |Vtd| accuracy from 16% to 11% Computations need to be confronted with experimental results 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 24

Semileptonic decays of c quarks In the charm sector: Vud Vus Vub Vcd Vcs Vcb Vtd Vts Vtb Vcd, Vcs  Constrained from measurements of the two first rows Using exclusive semileptonic decays of charm hadrons to measure form factors and validate Lattice QCD results Vcd Parameterized by form factors 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 25

Semileptonic decays of c quarks D  K l n and D  p l n decays Phys. Lett. B317 (1993) 647  High accuracy needed to measure the q2- dependence 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 26

Semileptonic decays of c quarks Lattice QCD form factors (D  K, D  p) Fermilab + MILC, hep-ph/0408306  BES, Phys. Lett. B597 (04) 39 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 27

Semileptonic decays of c quarks Charm Semileptonic Decays: Calibrate Lattice QCD results Improve results on B decays fp , fB , fB* , g B*Bp |Vub| measurement: 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 28

(4S) @ B factories Y(3770) Experimental setups @ charm factories BELLE CLEO-c BES-III BABAR DD BB 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 29

(4S)  cc Y(3770)  DD Experimental setups Some advantages and disavantages (4S)  cc Y(3770)  DD Large cc (~1.3 nb) Very large DD (~6 nb) Very large statistics Low multiplicity Vertex separation Small background Fragmentation (c D* = 26%) Well known En Background Still few data 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 30

Experimental techniques At the Y(3770) Unique kinematics: pp (GeV) CLEO-c DE=Ebeam-ED No PID DU=Emiss-pmiss s.l. channel D  p e n CLEO-c hep-ex/0408077 D  K e n D  p e n Preliminary DU=Emiss-pmiss (GeV) Tagged D CLEO-c Events/5 Mev 10183  112 Events/1 Mev 60 pb-1 Expected resolution on q2 ~ 0.03 GeV2 MD (GeV) DU=Emiss-pmiss (GeV) 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 31

Experimental techniques At the (4S) bb/cc separation  event shape variables BB Continuum events: e+e- cc cc En estimation  from all particles in the event D*+  D0 + s ~ 0.35 GeV q2 = (pl + pn)2 = ( pD – pK )2 50904 evts Events/1.6 Mev data Resolution on q2 found ~ 0.05-0.25 GeV2 Events/2.7 Mev 19.5 fb-1 D  K e n Background contribution  Dm (GeV) Dm (GeV) 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 32

Experimental techniques Comparisons: 2006 6.7 fb-1 60 pb-1 3 fb-1 ? 20 fb-1 300 fb-1 10K 6K 1800 90K 30K 450K 0.9K 0.3K 175 9K 3K 45K * D  K form factor by FOCUS with 6K events *Challenge: background suppression BaBar 5 times more stat. only with 20 fb-1 (Run1) 0.4 0.22 0.03 0.05-0.25 And good q2 resolution Phys.Lett. B607 (2005) 233-242 3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 33

 Summary |Vcb| and |Vub| are key elements of the CKM matrix |Vcb| accuracy is at the 1.2% level (world average) by using inclusive decays and OPE Charm Semileptonic Decays provide a way to calibrate Lattice-QCD computations Improve |Vub|  3/11/05 - Physikalisches Institut, Universität Bonn A. Oyanguren 34