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Flavour Physics at t -c Factories

Flavour Physics at t -c Factories. Stefano Bianco Laboratori Nazionali di Frascati dell’INFN Frascati, January 19 th , 2006. CONTENTS. Past , Present and Foreseeable Future for TauC factories Flavour (Charm) Physics(see Antonio’s talk for onium)

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Flavour Physics at t -c Factories

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  1. Flavour Physics at t-c Factories Stefano Bianco Laboratori Nazionali di Frascati dell’INFN Frascati, January 19th, 2006 SB - Flavour physics at tau-charm Factories

  2. CONTENTS • Past , Present and Foreseeable Future for TauC factories • Flavour (Charm) Physics(see Antonio’s talk for onium) • A List Of Open Questions and A Few Answers SB - Flavour physics at tau-charm Factories

  3. Past , Present and Foreseeable Future for TauC factories SB - Flavour physics at tau-charm Factories

  4. Charm discoveryK.Niu, E. Mikumo, Y. MaedaProg. Theor. Phys. 46 (1971) 1644D+ K+p0 First observation of D mesons at acceleratorsI.Peruzzi et al., Phys. Rev. Lett.37(1976) 569. SB - Flavour physics at tau-charm Factories

  5. MARK IIII ARGUS NA14 E691 BES CLEO2CLEO-C NA1 PANDA Charm quark detectors over the years CDF,D0 COMPASS BABAR,BELLE NOW R704E760E835 BNL SPEAR ADONE SB - Flavour physics at tau-charm Factories

  6. e+e-y(3770)DDWHY ? • Large s, low multiplicity • Pure initial state: no fragmentation • Double tag measurements: no background • Clean neutrino reconstruction • Coherent initial state • √s =3.770GeV (y’’) coherent production of D meson pair CLEO-c SB - Flavour physics at tau-charm Factories

  7. Tau-charm Factories proposed in the past • 1987 proposed at CERN • 1989 proposed at SLAC • 1990 proposed in Spain • 1992 proposed in ITEP • 1994 proposed at Argonne • 1996 micro-workshop at Frascati (G.Capon Convener) • … • 2005 a study in Frascati SB - Flavour physics at tau-charm Factories

  8. THE CHARMING COMPETITION • CLEO-c tau-charm factory, running. goal=3fb-1 DD • started Sep 2003, as of April 2005 265 pb-1 integrated at y’’. Luminosity below project goal=3 1032cm-2s-1. End in 2008. • Beijing tau-charm factory BEPC-II, design 1033cm-2s-1, commissioning in 2006 • BABAR (end in 2008) • BELLESBELLE ??? • Frascati tau-charm Study (2005): • 2x108 reconstructed DD events • L=1034cm-2s-1 • 100fb-1/y • start in 2011 • 30x CLEO-c • 2x BEPC-II after 1 y • ~10x BABAR/SBELLE with much better systematics SB - Flavour physics at tau-charm Factories

  9. 93% of 4p sp/p = 0.35% @1GeV dE/dx: 5.7% p @minI 83% of 4p 87% Kaon ID with 0.2% p fake @0.9GeV 1.5 T now,... 1.0T later 93% of 4p sE/E = 2% @1GeV = 4% @100MeV Trigger: Tracks & Showers Pipelined Latency = 2.5ms Data Acquisition: Event size = 25kB Thruput < 6MB/s 85% of 4p For p>1 GeV Detector(CLEOIII –like)VERYCHALLENGINGAND AMBITIOUS • tracker • RICH • ECAL • solenoid • ermetic 4p geometry • potent DAQ • open trigger SB - Flavour physics at tau-charm Factories

  10. 2. Flavour Physicsat a tau-C Factory(see Antonio’s talk for onium) SB - Flavour physics at tau-charm Factories

  11. c-QCD LO ENERGY HI ENERGY High-impact Physics & Engineering Database Higgs ? SM Why (only) 3 families ? Quark c is the lightest heavy quark Quark c is the only HQ up-type probe But how small? CPV asimm 10-3 D0D0bar mixing 10-3—10-10 Rare decays 10-9 – 10-19 Quantitative predictions via 1/mQ expansions are possible In the charm sector, SM contributions to CPV, mixing and rare decays are small (GIM) FSI corrections are important FSI corrections are important CPV, mixing and rare decays in Charm sector are a probe for New Physics Studying the c-quark provides sensitivity and discovery potential for New Physics. After the discovery (?) of Higgs @ LHC, New Physics manifestations in c-quark (and in b-quark) important to distinguish among models. SB - Flavour physics at tau-charm Factories

  12. e+e-y(3770)DD“NEW PHYSICS” PROGRAMME • √s =3.770GeV (y’’) coherent production of D meson pairs • L~1034cm-2s-1, 100 fb-1/y • 2x108 DD pairs detected (30% eff*acc, extrap. from CLEO-c) , in uniquely clean environment, per year. • Search for New Physics: • Direct CP Violation in SCSD asymmetries, and directly in integrated rates. Sensitivity 10-4, SM PREDICTION 10-3. • Search for direct CPV in CFD and/or DCSD, where SM PREDICTS NO CPV • Mixing exploiting coherence, unique feature of threshold production. Cannot study mixing in time evolution of rates, but only in integrated rates. In most channels, DCSD concurrent process does not exist thanks to Bose-Einstein statistics (coherent C=-1 quantum state). By comparing semilept and hadronic, measure strong phaseshift d. • Rare decays: FCNC D+ h l+l-, D0l+l-, SM PREDICTION 10-9Sensitivity 10-7 - 10-8 • Bibliography: • SB, Fabbri, Benson, Bigi Riv.Nuovo Cim. 26,7-8, 2003 hep-ex/0309021. • I.Bigi and A.Sanda CP Violation, Cambridge, 2000. • CLEO-c proposal (2001). • Burdman Shipsey Annu. Rev. Nucl. Part. Sci. 2003. 53:431–99 • Frascati Futuro report (Antonelli, SB, Bloise, Bossi, Miscetti et al.) SB - Flavour physics at tau-charm Factories

  13. Also, tau physicse+e-y’’t+t- • √s =3.770GeV (y’’) production of tau lepton pairs, s~3nb. • L~1034cm-2s-1, 100 fb-1/y • LNV decay tmg sensitive to SUSY, (109 events) / (three years). BABAR best limit 7x10-8 (90%cl) dominated by systematics, background ttg. Running at threshold reduces systematics. • Robust Standard Model physics programme: • precise measurement of mass • weak couplings (purely leptonic and semileptonic decays) • test of CVC rule, and implications on anom. magn. moment of muon. • etc (see Gino Isidori’s talk April 2005 Frascati, and Futuro report Sect.5.5) SB - Flavour physics at tau-charm Factories

  14. CPV ASYMMETRIES SB - Flavour physics at tau-charm Factories

  15. CP VIOLATING INTEGRATED ASYMMETRIES Atot= g1M1eid1 + g2M2eid2 CP conjugate Atot= g1M1eid1 + g2M2eid2 * * 2Im(g2 g1*) sin(d1-d2)M1M2 |Atot|2-|Atot|2 aCP= = |Atot|2+|Atot|2 |g1|2M12+|g2|2M22+2Re(g2 g1*)cos(d1-d2)M1M2 For a two-amplitude decay di= strong phase CP asymmetry: strong phase-shift 2 different weak amplitudes are needed for CPV asymmetry  Single Cabibbo-suppressed decays In DSCD and CFD only one weak amplitude  NO CPV WITHIN SM SB - Flavour physics at tau-charm Factories

  16. In plain words… • SM predicts CPV at the 10-3 level in SCSD  observation would be a *** result • SM predicts ZERO CPV in CFD and DCSD  observation of CPV in those decays is a ***** discovery of New Physics SB - Flavour physics at tau-charm Factories

  17. Search for CP violation via Dalitz plot analysis of Singly-Cabibbo-suppressed Decays • Use full decay info, not only BR  must determine amplitude coefficients and phases • Final state results from the interference of all intermediate states • Differences between amplitude and/or phases patterns in a Dalitz analysis betw conjugate states (i.e., D+ vs D-), would be evidence of CP violation • (ref. I.Bigi,A.Sanda “CP Violation”) SB - Flavour physics at tau-charm Factories

  18. Ds ,D+ KK Ds+ K+ K- p+ D+ K+ K- p+ SB - Flavour physics at tau-charm Factories

  19. D±KK Decay Fraction and phases K*(892) = 20.7  1.0 % (0 fixed) f(1020) = 27.8  0.7 % (243.1 5.2)° K*(1410) = 10.7  1.9 % (-47.4  4.9)° K*(1430) = 66.5  6.0 % (61.8  3.8)° f0(1370) = 7.0  1.1 % (60.0  5.3) ° a0(980) = 27.0  4.8 % (145.6  4.3)° f2(1270) = 0.8  0.2 % (11.6  7.0) ° f(1680) = 1.6  0.4 % (-74.3  7.5) ° K+ K- projection K-p + projection Preliminary Yield D± = 7106 92 S/N D± = 8.62 SB - Flavour physics at tau-charm Factories

  20. D+/D- split sample analysis Preliminary! Coefficients: D±,D+,D- No evidence of CPV Phases:D±,D+,D- SB - Flavour physics at tau-charm Factories

  21. D0D0 MIXING SB - Flavour physics at tau-charm Factories

  22. Formalism of P0-P0 mixing The time evolution of flavour eigenstates is given by the Schrödinger equation mixing can be described by the ratior Processes which allow mixing appear in H12andH21. If are not mass eigenstates. Mass eigenstates are (assuming CP conservation) , |x|>0 mixing is caused by genuine transitions(Df=2) x splits masses |y|>0 mixing is caused by the short-lived component disappearing rapidly, leaving behind the long-lived component, made of and ysplitslifetimes and mixing amplitude is Mass and width differences are parametrized by SB - Flavour physics at tau-charm Factories

  23. K0, D0, B0 _ Where’s The Difference ? SHORT DISTANCE LONG DISTANCE KK,pp p0,h SB - Flavour physics at tau-charm Factories

  24. _ “D0D0mixing is a window on New Physics” Theoretical “guidance” From compilation of H.N.Nelson hep-ex/9908021 Triangles are SMxSquares are SMy Circles are NSMx SB - Flavour physics at tau-charm Factories

  25. _ TECHNIQUES FOR STUDYING D0D0 MIXING (I) Measure r MeasureyCP, the y parameter for CP eigenstates 2 HADRONIC DECAYS SEMILEPTONIC DECAYS (1 +2)/2 SB - Flavour physics at tau-charm Factories

  26. _ TECHNIQUES FOR STUDYING D0D0 MIXING (II) via HADRONIC DECAYS Measurer Cabibbo-Favoured Decay mixing Strong phased between CFD and DCSD mixesxandy D* tags D0 flavour Double Cabibbo-Suppressed Decay SB - Flavour physics at tau-charm Factories

  27. _ TECHNIQUES FOR STUDYING D0D0 MIXING (III) via SEMILEPTONIC DECAYS Measurer Cabibbo-Favoured Decay mixing D* tags D0 flavour SB - Flavour physics at tau-charm Factories

  28. _ TECHNIQUES FOR STUDYING D0D0 MIXING (Concl.) • Direct measurement of yCP requires good lifetime resolution • Measuring rws in hadronic decays requires • to disuntangle rDCS from r; • and the knowledge of d • Measuring rws in semileptonic decays provides the r parameter, but it is experimentally more difficult • MEASURING rws at tau-C PROVIDES THE r PARAMETER, SINCE QUANTUM CORRELATIONS FORBID DECAY TO IDENTICAL FINAL STATES (NO DCSD POLLUTION). SB - Flavour physics at tau-charm Factories

  29. STATUS OFD0D0MIXINGAS OF SPRING 2004 d SB - Flavour physics at tau-charm Factories

  30. e+e-y(3770)DDSTANDARD MODEL FLAVOUR PHYSICS • √s =3.770GeV (y’’) coherent production of D meson pairs, L~1034cm-2s-1, 100 fb-1/y • 2x108 DD pairs detected (30% eff*acc, extrap. from CLEO-c) , in uniquely clean environment, per year. • Standard Model physics programme: Absolute branching ratios; Vcd, Vcs from semileptonic decays; SL Form Factors; Charm decay constants fD from Dmn; light quarks in Dalitz plots; etc. Ref: SB, Fabbri, Benson, Bigi Riv.Nuovo Cim. 26,7-8, 2003 hep-ex/0309021. I.Bigi and A.Sanda CP Violation, Cambridge, 2000. SB - Flavour physics at tau-charm Factories

  31. e+e-J/ygX • Charmonium spectroscopy • QCD • Hybrids, glueballs SB - Flavour physics at tau-charm Factories

  32. QUESTIONS, AND MY VERY FEW ANSWERS • Physics • Is the tcF a significant help to disentangle among non-SM models after the discovery of SUSY ? • Are the SM measurements significant in the field of b and c physics ? • Is the SM programme of a tcF strong enough to allow success even is SUSY is not discovered at LHC ? • Detector • must be all-purpose detector ! • Can we start design ? • Impact on Frascati infrastructure ? VERY BIG, INTERNATIONAL ENTERPRISE • Cost ? • Machine • Impact on Frascati infrastructure ? VERY BIG, INTERNATIONAL ENTERPRISE • symmetric/asymmetric ? • Fits DAFNE building ? NO • Cost 100MEuro ? MORE • Competition • Is a 2011 Frascati tcF going to be competitive and timely wrt CLEO-c and BES ? • Is a tcF really necessary after BABAR and, expecially, BELLE/SBELLE ? • Sociology • Is the Frascati community interested in working hard on a onsite world-class project ? YES ! • Is the whole INFN community interested ? • Is the world community interested ? • This is a Big Science project, Isn’t Big Science HEP over ? SB - Flavour physics at tau-charm Factories

  33. http://www.lnf.infn.it/conference/dif06/ SB - Flavour physics at tau-charm Factories

  34. CONCLUSIONS • Flavour physics is necessary in the LHC era if “Beyond the SM • Physics” is discovered • The Physics programme at a tau-C factory is very large • and robust: • BSM: CPV, Mixing, Rare decays, tau rare decays • SM: absolute branching ratios, meson decay constants, • CKM elements from semileptonic decays, charmonium • spectroscopy • with some items unique or superior wrt B-factories • (underlined above). Is this uniqueness sufficient to justify it ? • Machine and detector are likely to be costly and challenging, • expertise does exist in Frascati but has to be an international • enterprise. • Timing is the critical issue against competition SB - Flavour physics at tau-charm Factories

  35. QUESTIONS SLIDES SB - Flavour physics at tau-charm Factories

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