1 S. Stone Syracuse Univ. May 2003 Heavy Quark Physics Far too much interesting Material to include in 40 min. Apologies in advance.

2 Physics Goals  Discover, or help interpret, New Physics found elsewhere using b & c decays - There is New Physics out there: Standard Model is violated by the Baryon Asymmetry of Universe & by Dark Matter  Measure Standard Model parameters, the “fundamental constants” revealed to us by studying Weak interactions  Understand QCD; necessary to interpret CKM measurements

3 The Basics: Quark Mixing & the CKM Matrix  A,,  and  are in the Standard Model fundamental constants of nature like G, or  EM   multiplies i and is responsible for CP violation  We know =0.22 (V us ), A~0.8; constraints on  &  d s b u c t mass massmass

4 The 6 CKM Triangles  From Unitarity  “ds” - indicates rows or columns used  There are 4 independent phases:   (  can be substituted for  or  )     

5 All of The CKM Phases  The CKM matrix can be expressed in terms of 4 phases, rather than, for example, A, ,    not independent   &  probably large,  small ~1 o,  smaller

6 Required Measurements  |V ub /V cb | 2 = (  2 +  2 )/ 2 use semileptonic B decays   m d and  m s are measured directly in B d and B s mixing. There is a limit on the ratio which is a function of V td /V ts and depends on (1-  ) 2 +  2   K is a measure of CP violation in K L decays, a function of ,  and A  Asymmetries in decay rates into CP eigenstates f (or other states) measure the angles  & , sometimes with little or no theoretical model errors BoBo BoBo

7 | V ub | a case study  Use semileptonic decays  c >> u, so difficult exp  Also difficult theoretically  Three approaches  Endpoint leptons: Clear signal seen first this way; new theory enables predictions  Make mass cuts on the hadronic system; plot the lepton spectrum. Problems are the systematic errors on the experiment and the theory.  Exclusive B    or   decays. Data are still poor as is theory. Eventually Lattice Gauge calculations should be able to remove this problem

8 V ub from lepton endpoint  V ub both overall rate & fraction of leptons in signal region depends on model. Use CLEO b  s  spectrum to predict shape  CLEO: V ub =(4.08±0.34 ±0.44±0.16 ±0.24)x10 -3  BABAR: V ub =(4.43±0.29 ±0.25±0.50 ±0.35)x10 -3 theory errs : V ub formula, using s   Luke: additional error >0.6x10 -3 due to: CLEO  Y(4S) data  b  c   continuum Shape from b  s   b  u subleading twist, annihilation CLEO

9 V ub Using Inclusive Leptons  ALEPH & DELPHI, OPAL select samples of charm-poor semileptonic decays with a large number of selection criteria  Mass < M D  b  u  Can they understand b  c feedthrough < 1% ?  |V ub |=(4.09  0.37  0.44  0.34)x10 -3 DELPHI

10 Problem According to Luke PROBLEM:  QCD m B and m D 2 aren’t so different! ïkinematic cut and singularity are perilously close … SOLUTION: Also require q 2 >~7 GeV 2

11 V ub using reconstructed tags - BABAR  Use fully reconstructed B tags  |V ub |=(4.52  0.31 (stat)  0.27 (sys)  0.40 (thy)  0.09 (pert)  0.27 (1/m b 3 ) ) x10 -3 Preliminary

12 V ub from Belle  Two techniques (Both Preliminary) |V ub | = 5.00  0.60  0.23  0.05  0.39  0.36  stat.syst. |V ub | = 3.96  0.17  0.44  0.34  0.26  0.29  bcbcbubu stat.syst. bcbcbubu “D ( * ) ln tag” “ reconstruction and Annealing uses Mx 7” theor.

13 V ub from exclusives: B   B   Use detector hermeticity to reconstruct  CLEO finds rough q 2 distribution  BABAR finds (GeV) CLEO

14 |V ub | Summary  All measurements nicely clustered. RMS ~0.3x10 -3  However, there are theoretical errors that might all have not been included (see Luke)  Also previous values may have influenced new values  Safe to say |V ub |=(4.0±1.0)x10 -3  Future:  More and better tagged data from B-factories  Lattice calculations (unquenched) for exclusives in high q 2 region

15 B d Mixing in the Standard Model  Relation between B mixing & CKM elements:  F is a known function,  QCD ~0.8  B B and f B are currently determined only theoretically  in principle, f B can be measured, but its very difficult, need to measure B o   Current best hope is Lattice QCD

16 B s Mixing in the Standard Model  When B s mixing is measured then we will learn the ratio of V td /V ts which gives the same essential information as B d mixing alone:  |V td | 2 =A 2 4 [(1-  ) 2 +  2 ]  1/f B B B 2  |V td | 2 / |V ts | 2 =[(1-  ) 2 +  2 ]  f Bs B Bs 2 /f B B B 2  Circle in (  ) plane centered at (1,0)  Lattice best value for Partially unquenched

17 Upper limits on  m s  P(B S  B S )=0.5 X  S e -  S t [1+cos(  m S t)]  To add exp. it is useful to analyze the data as a function of a test frequency   g(t)=0.5  S e -  S t [1+  cos(  t)] 4  discovery limit  LEP + SLD

18 Status of sin(2  ) B 0  f CP sin2b =   BABAR sin2b =0.719   Belle sin2b = 0.73  0.06 Average sin2b =   BABAR sin2b =0.719   Belle sin2b = 0.73  0.06 Average 78 fb -1 f CP =J/  K s,  K s, etc.. No theoretical uncertainties at this level of error

19 Current Status  Constraints on  &  from Nir using Hocker et al.  Theory parameters exist except in Asymmetry measurements, because we measure hadrons but are trying to extract quark couplings. They are allowed to have equal probability within a restricted but arbitrary range  Therefore large model dependence for V ub /V cb,  K and  m d, smaller but significant for  m s and virtually none for sin(2  ). The level of theoretical uncertainties is arguable      sin(2  ) sin(2  ) may be consistent with other measurements

20 for s get K - Bo+-Bo+-  In principle, the CP asymmetry in B o     measures the phase . However there is a large Penguin term (a “pollution”) (CLEO+ BABAR+BELLE): B (B o  +  - ) = (4.8 ±0.5)x10 -6 B (B o  K ±   ) =(18.6±1.0)x10 -6  A CP (  t)=S  sin(  m d  t)-C  cos(  m d  t), where S    C     To measure , use B o   see Snyder & Quinn PRD 48, 2139 (1993) )

21 Results Inconsistent Results! S  C  S  2 +C  2 Belle -1.23± ± ±2.2 BABAR 0.02± ± ±  t (ps) BABAR Each exp ~80 fb -1

22 Progress on   Best way to measure  is  2 nd best is  Another suggestion is D o  K* ± K  (Grossman, Ligeti & Soffer hep-ph/ )

23 Currently available data  Belle signals (also B + ) Where  is a strong phase &  These data do not constrain   BABAR has similar results signal

24 New Physics Tests  We can use CP violating or CP related variables to perform tests for New Physics, or to figure out what is the source of the new physics.  There are also important methods using Rare Decays, described later  These tests can be either generic, where we test for inconsistencies in SM predictions independent of specific non-standard model, or model specific

25 Generic test: Separate Checks  Use different sets of measurement s to define apex of triangle (from Peskin)  Also have  K (CP in K L system) Magnitudes B d mixing phase B s mixing phase Can also measure  via B -  D o K -

26 Generic Test: Critical Check using   Silva & Wolfenstein (hep-ph/ ), (Aleksan, Kayser & London), propose a test of the SM, that can reveal new physics; it relies on measuring the angle .  Can use CP eigenstates to measure  B s  J/       Can also use J/  but a complicated angular analysis is required  The critical check is:  Very sensitive since  ±  Since  ~ 1 o, need lots of data

27 Rare b Decays  New fermion like objects in addition to t, c or u, or new Gauge-like objects  Inclusive Rare Decays such as inclusive b  s , b  d , b  s +   Exclusive Rare Decays such as B  B  K* +  : Dalitz plot & polarization  + -  A good place to find new physics Ali et. al, hep-ph/ SUSY examples

28 Inclusive b  s   CLEO B (b  s  )= (2.85 ± 0.35 ± 0.23)x10 -4  +ALEPH, Belle & Babar Average (3.28 ± 0.38)x10 -4 Theory (3.57 ± 0.30)x10 -4 CLEO

29 Implications of B (b  s  ) measurement  Measurement is consistent with SM  Limits on many non-Standard Models: minimal supergravity, supersymmetry, etc…  Define ala’ Ali et al. R i =(c i SM +c i NP )/c i SM ; i=7, 8  Black points indicate various New Physics models (MSSM with MFV) SM

30 B  K (*) + -  Belle Discovery of K + -  They see K  +  -   BABAR confirms in Ke + e -  Only u.l. on K* + -

31 B  X s + -  Belle finds B (b  s + - ) = (6.1 ± 1.4 )x10 -6  Must avoid J/ ,  ´  Important for NP  H eff = f(O 7, O 9, O 10 )

32 Tests in Specific Models: First Supersymmetry  Supersymmetry: In general 80 constants & 43 phases  MSSM: 2 phases (Nir, hep-ph/ )  NP in B o mixing:  D, B o decay:  A, D o mixing:  K  ProcessQuantity SMNew Physics B o  J/  K s CP asym sin(2  )sin2(  D ) BoKsBoKs CP asym sin(2  )sin2(  D  A ) DoK-+DoK-+ CP asym 0 ~sin(  K  ) NP Difference  NP

33 CP Asymmetry in B o  K s  Non-SM contributions would interfere with suppressed SM loop diagram  New Physics could show if there is a difference between sin(2  ) measured here and in J/  Ks  Measurements: BABAR: -0.18±0.51±0.07 Belle: -0.73±0.64±0.22 Average: -0.38±0.41  2.7  away from bears watching, as well other modes

34 relies on finite strong phase shift MSSM Predictions from Hinchcliff & Kersting (hep-ph/ )  Contributions to B s mixing CP asymmetry  0.1sin   cos   sin(  m s t), ~10 x SM B s  J  B-K-B-K-  Contributions to direct the CP violating decay Asym=(M W /m squark ) 2 sin(   ), ~0 in SM BABAR u.l Asy=(3.9±8.6±1.1)%

35 Extra Dimensions – only one  Extra spatial dimension is compactified at scale 1/R = 250 GeV on up  Contributions from Kaluza-Klein modes- Buras, Sprnger & Weiler (hep-ph/ ) using model of Appelquist, Cheng and Dobrescu (ACD)  No effect on |V ub /V cb |,  M d /  M s, sin(2  )

36 One Extra Dimension  Precision measurements needed for large 1/R –8% – %

37 SO(10) ala’ Chang, Masiero & Murayama hep-ph/  Large mixing between  and  (from atmospheric oscillations) can lead to large mixing between b R and s R.  This does not violate any known measurements  Leads to large CPV in B s mixing, deviations from sin(2  ) in B o  K s and changes in the phase  ~ ~

38 Possible Size of New Physics Effects  From Hiller hep-ph/

39 Revelations about QCD  BABAR discovery of new narrow D s +  o state and CLEO discovery of narrow D s * +  o state  Double Charm Baryons  The  C (2S) and implications for Potential Models (no time)  The Upsilon D States (no time)

40 The D s  o state  “ Narrow” state, mass ±0.4±3.0 MeV width consistent with mass resolution ~9 MeV found by BABAR  Lighter than most potential models  What can this be?  DK molecule Barnes, Close & Lipkin hep-ph/  “Ordinary” excited cs states: D**, narrow because isospin is violated in the decay. Use HQET + chiral symmetry to explain. Bardeen, Eichten & Hill hep-ph/  Etc… D s * New BABAR +

41 D s ** States  D s ** predicted J p : 0 +, 1 +, 1 + & 2 +. One 1 + & 2 + seen. Others predicted to be above DK threshold and have large ~200 MeV widths, but this state is way below DK threshold  The D s  o decay from an initial cs state violates isospin, this suppresses the decay width & makes it narrow. So the low mass ensures the narrow width  Decays into D s , D s *  and D s  +  - are not seen. If the 2317 were 1 + then it could decay strongly into D s  +  - but it cannot if it’s

42 CLEO Sees Two Mass Peaks  These two states can reflect into one another  D s  o  D s *  o not to bad, ~9%, because you need to pick up a random  D s * signal region D s * sideband region Ds*oDs*o DsoDso  m=349.3±1.1 MeV  =8.1±1.3 MeV  m= 349.8±1.3 MeV  = 6.1±1.0 MeV

43 Feed Down: D s (2460) Signal, Reconstructed as D s (2317) All events in the D s *  0 mass spectrum are used to show the D s (2460) signal “feed down” to the D s (2317) spectrum. Feed down rate is 84%

44 Unfolding the rates  We are dealing with two narrow resonances which can reflect (or feed) into one another  From the data and the MC rates can be unfolded

45 Upper Limits on other D s (2317) modes Mode Yield Efficiency(%) 90% cl Theory  Corrected for feed across  Theory: Bardeen, Eichten and Hill DsoDso 150±4913.1± DsDs -22±1318.4±0.9< Ds*Ds* -2.0± ±0.4< Ds+-Ds+- 1.6± ±0.7<

46 Belle Confirms Both States M(D s + π 0 ) M(D s *+ π 0 ) M=(2317.2±0.5) MeV  =(8.1 ±0.5) MeV M=(2459±1.9) MeV  =(7.0 ±1.7) MeV Also see “feed up”

47 Conclusions on D s **’s  CLEO confirms the BABAR discovered narrow cs state near 2317 MeV, measures mD s (2320)-mD s =350.4±1.2±1.0 MeV  CLEO has observed a new narrow state near 2463 mD s (2463)-mD s *=351.6±1.7±1.0 MeV  Belle confirms both states  The mass splittings are consistent with being equal (1.2±2.1 MeV) as predicted by BEH if these are the 0 + & 1 + states  The BEH model couples HQET with Chiral Symmetry and makes predictions about masses, widths and decay modes.  These results provide powerful evidence for this model  Seen modes and u.l. are consistent with these assignment; except 1 +  D s  +  - is above threshold for decay, predicted to be 19% but is limited to 90% c. l.

48 Selex: Two Isodoublets of Doubly Charmed Baryons  cc ++ (J=1/2 + )?  cc ++ (J=1/2 - )?  cc + (J=1/2 + )?  cc + (J=1/2 - )? Consider as (cc)q - BEH

49 The Future  Now & near term  Continuation of excellent new results from Belle & BABAR  B s physics, especially mixing from CDF & D0  CLEO-c will start taking data in October on   LHC era  Some b physics from ATLAS & CMS  Dedicated hadronic b experiments: LHCb & BTeV (at the Tevatron) – enhanced sensitivity to new physics

50 Summary of Required Model Independent Measurements for CKM tests

51 CDF measures B s  D s  - needed for B s mixing   For f s /f d = 0.27±0.03, B(B s )/B(B d )=1.6±0.3 + o

52 BTeV & LHCb  Dedicated Hadron Collider B experiments  Tevatron LHC LHCb Could find narrow B s ** states P b WO 4

53 BTeV & LHCb  Physics highlights  Sensitivity to B s mixing up to x s ~80  Large rare decay rates B o  K* o  +  - ~2500 events in 10 7 s  Measurement of  to ~7 o using B s  D s K -  Measurement of  to ~4 o using B o  (BTeV)  Measurement of  to ~1 o using B o  J/  (BTeV)

54 Conclusions  There have been lots of surprises in Heavy Quark Physics, including:  Long b Lifetime  B o – B o mixing  Narrow D s ** states  We now expect to find the effects of New Physics in b & c decays!