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S. Stone Syracuse Univ. May 2003

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

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S. Stone Syracuse Univ. May 2003

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  1. S. StoneSyracuse 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 d s b mass u c m a s s t • A, l, r and h are in the Standard Model fundamental constants of nature like G, or aEM • h multiplies i and is responsible for CP violation • We know l=0.22 (Vus), A~0.8; constraints on r & h

  4. The 6 CKM Triangles • From Unitarity • “ds” - indicates rows or columns used • There are 4 independent phases: b, g, c, c (a can be substituted for g or b) c c g b a

  5. All of The CKM Phases • The CKM matrix can be expressed in terms of 4 phases, rather than, for example l, A, r,h: • a= p-(b+g), not independent • a, b & g probably large, c small ~1o, c smaller

  6. Required Measurements • |Vub/Vcb|2 = (r2+ h2)/l2 use semileptonic B decays • Dmd and Dms are measured directly in Bd and Bs mixing. There is a limit on the ratio which is a function of Vtd/Vts and depends on (1-r)2+h2 • eK is a measure of CP violation in KL decays, a function of h, r and A • Asymmetries in decay rates into CP eigenstates f (or other states) measure the angles a, b, g & c, sometimes with little or no theoretical model errors Bo Bo

  7. |Vub | 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 pln orrln decays. Data are still poor as is theory. Eventually Lattice Gauge calculations should be able to remove this problem

  8. Vub from lepton endpoint CLEO • Vub both overall rate & fraction of leptons in signal region depends on model. Use CLEO b sgspectrum to predict shape • CLEO: Vub=(4.08±0.34 ±0.44±0.16 ±0.24)x10-3 • BABAR: Vub=(4.43±0.29 ±0.25±0.50 ±0.35)x10-3theory errs : Vub formula, using sg • Luke: additional error >0.6x10-3 due to:  Y(4S) data bcln + continuum CLEO  buln Shape from b sg subleading twist, annihilation

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

  10. Problem According to Luke • PROBLEM: • LQCDmB and • mD2 aren’t so different! • kinematic cut and singularity are perilously close … SOLUTION: Also require q2>~7 GeV2

  11. Vub using reconstructed tags - BABAR • Use fully reconstructed B tags • |Vub|=(4.520.31(stat)0.27(sys) 0.40(thy)0.09(pert) 0.27(1/mb3)) x10-3 Preliminary

  12. Vub from Belle • Two techniques (Both Preliminary) “D(*)ln tag” |Vub| = 5.00  0.60  0.23  0.05  0.39  0.36  10-3 bc bu stat. syst. theor. “n reconstruction and Annealing uses Mx < 1.5, q2 > 7” |Vub| = 3.96  0.17  0.44  0.34  0.26  0.29  10-3 bc bu stat. syst. theor.

  13. (GeV) Vub from exclusives:Bpln & Brln CLEO • Use detector hermeticity to reconstruct n • CLEO finds rough q2 distribution • BABAR finds

  14. |Vub | 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 |Vub|=(4.0±1.0)x10-3 • Future: • More and better tagged data from B-factories • Lattice calculations (unquenched) for exclusives in high q2 region

  15. Bd Mixing in the Standard Model • Relation between B mixing & CKM elements: • F is a known function, hQCD~0.8 • BB and fB are currently determined only theoretically • in principle, fB can be measured, but its very difficult, need to measure Boln • Current best hope is Lattice QCD

  16. Bs Mixing in the Standard Model • When Bs mixing is measured then we will learn the ratio of Vtd/Vts which gives the same essential information as Bd mixing alone: • |Vtd|2=A2l4[(1-r)2+h2]  1/fBBB2 • |Vtd|2/ |Vts|2=[(1-r)2+h2]  fBsBBs2/fBBB2 • Circle in (r,h) plane centered at (1,0) • Lattice best value for Partially unquenched

  17. Upper limits on Dms • P(BSBS)=0.5X GSe-GSt[1+cos(DmSt)] • To add exp. it is useful to analyze the data as a function of a test frequency w • g(t)=0.5 GS e-GSt[1+Acos(wt)] LEP + SLD 4s discovery limit A

  18. Status of sin(2b) No theoretical uncertainties at this level of error sin2b = 0.7410.0670.034 BABAR sin2b = 0.7190.0740.035 Belle sin2b = 0.73  0.06 Average B0 fCP B0 fCP 78 fb-1 fCP=J/yKs, yKs, etc..

  19. Current Status sin(2b) may be consistent with other measurements • Constraints on r & h 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 Vub/Vcb, eK and Dmd, smaller but significant for Dms and virtually none for sin(2b). The level of theoretical uncertainties is arguable a sin(2b) g h b r

  20. for s get K- Bop+p- • In principle, the CP asymmetry in Bop+p- measures the phase a. However there is a large Penguin term (a “pollution”) (CLEO+ BABAR+BELLE): B(Bop+p-) = (4.8 ±0.5)x10-6 B(BoK±p) =(18.6±1.0)x10-6 • ACP(Dt)=Sppsin(DmdDt)-Cppcos(DmdDt), where Spp2+Cpp2<1 • To measure a, use Borp (see Snyder & Quinn PRD 48, 2139 (1993))

  21. Results Inconsistent Results! Spp Cpp Spp2+Cpp2 Belle -1.23±0.42 0.77±0.28 2.1±2.2 BABAR 0.02±0.34 -0.30±0.34 0.1±0.3 BABAR Each exp ~80 fb-1 -5 0 5 Dt (ps) Must be < 1

  22. Progress on g • Best way to measure g is • 2nd best is • Another suggestion is DoK*±K (Grossman, Ligeti & Soffer hep-ph/0210433)

  23. Currently available data signal • Belle signals (also B+) Whered is a strong phase & • These data do not constrain g • BABAR has similar results

  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 measurements to define apex of triangle (from Peskin) • Also have eK (CP in KL system) Bd mixing phase Magnitudes Bs mixing phase Can also measure g via B-DoK-

  26. Generic Test: Critical Check using c • Silva & Wolfenstein (hep-ph/9610208), (Aleksan, Kayser & London), propose a test of the SM, that can reveal new physics; it relies on measuring the angle c. • Can use CP eigenstates to measure c BsJ/yh() ,hgg,hrg • Can also use J/yf, but a complicated angular analysis is required • The critical check is: • Very sensitive since l =0.2205±0.0018 • Sincec~ 1o, need lots of data

  27. New fermion like objects in addition to t, c or u, or new Gauge-like objects Inclusive Rare Decays such as inclusive bsg, bdg, bsl+l- Exclusive Rare Decays such as Brg, BK*l+l-: Dalitz plot & polarization Ali et. al, hep-ph/9910221 Rare b Decays • A good place to find new physics g, l+l- SUSY examples

  28. Inclusive bsg • CLEO B(bsg)= (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sg ) measurement • Measurement is consistent with SM • Limits on many non-Standard Models: minimal supergravity, supersymmetry, etc… • Define ala’ Ali et al. Ri=(ciSM+ciNP)/ciSM ; i=7, 8 • Black points indicate various New Physics models (MSSM with MFV) SM

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

  31. BXsl+l- • Heff = f(O7, O9, O10) • Belle finds B(bsl+l- )= (6.1±1.4)x10-6 • Must avoid J/Y, Y´ • Important for NP +1.4 -1.1

  32. Difference  NP NP Tests in Specific Models:First Supersymmetry • Supersymmetry: In general 80 constants & 43 phases • MSSM: 2 phases (Nir, hep-ph/9911321) • NP in Bo mixing: qD ,Bodecay: qA,Do mixing: fKp

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

  34. Contributions to direct the CP violating decay relies on finite strong phase shift B-fK- Asym=(MW/msquark)2sin(fm), ~0 in SM BABAR u.l Asy=(3.9±8.6±1.1)% MSSM Predictions from Hinchcliff & Kersting (hep-ph/0003090) BsJ/yh • Contributions to Bs mixing CP asymmetry  0.1sinfmcosfAsin(Dmst), ~10 x SM

  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/0212143) using model of Appelquist, Cheng and Dobrescu (ACD) • No effect on |Vub/Vcb|, DMd/DMs, sin(2b)

  36. One Extra Dimension • Precision measurements needed for large 1/R +72% –100 –8%

  37. SO(10)ala’ Chang, Masiero & Murayama hep-ph/0205111 • Large mixing between nt and nm (from atmospheric n oscillations) can lead to large mixing between bR and sR. • This does not violate any known measurements • Leads to large CPV in Bs mixing, deviations from sin(2b) in Bof Ks and changes in the phase g ~ ~

  38. Possible Size of New Physics Effects • From Hiller hep-ph/0207121

  39. Revelations about QCD • BABAR discovery of new narrow Ds+po state and CLEO discovery of narrow Ds*+po state • Double Charm Baryons • The hC(2S) and implications for Potential Models (no time) • The Upsilon D States (no time)

  40. * s D The Dspo state + BABAR • “Narrow” state, mass 2316.8±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/0305025 • “Ordinary” excited cs states: D**, narrow because isospin is violated in the decay. Use HQET + chiral symmetry to explain. Bardeen, Eichten & Hill hep-ph/0305049 • Etc… New

  41. Ds** States + • Ds** predicted Jp: 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 Dspo 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 Dsg, Ds*g and Ds p+p- are not seen. If the 2317 were 1+ then it could decay strongly into Ds p+p- but it cannot if it’s 0+ + + + + +

  42. CLEO Sees Two Mass Peaks Ds*po Dspo Dm=349.3±1.1 MeV s=8.1±1.3 MeV Dm= 349.8±1.3 MeV s= 6.1±1.0 MeV Ds* signal region • These two states can reflect into one another • DspoDs*po not to bad, ~9%, because you need to pick up a random g Ds* sideband region

  43. Feed Down: Ds(2460) Signal, Reconstructed as Ds(2317) All events in the Ds*p0 mass spectrum are used to show the Ds(2460) signal “feed down” to the Ds(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 Ds(2317) modes Mode Yield Efficiency(%) 90% cl Theory • Corrected for feed across • Theory: Bardeen, Eichten and Hill

  46. Belle Confirms Both States M=(2459±1.9) MeV s=(7.0 ±1.7) MeV M=(2317.2±0.5) MeV s=(8.1 ±0.5) MeV Also see “feed up” M(Ds*+π0 ) M(Ds+π0 )

  47. Conclusions on Ds**’s • CLEO confirms the BABAR discovered narrow cs state near 2317 MeV, measures mDs(2320)-mDs =350.4±1.2±1.0 MeV • CLEO has observed a new narrow state near 2463 mDs(2463)-mDs*=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+ Dsp+p- is above threshold for decay, predicted to be 19% but is limited to <8.1% @ 90% c. l.

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

  49. The Future • Now & near term • Continuation of excellent new results from Belle & BABAR • Bs physics, especially mixing from CDF & D0 • CLEO-c will start taking data in October on y • 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

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