Super c/ t factory Budker INP, Novosibirsk Bondar A.

1. Super c/t factory Budker INP, Novosibirsk Bondar A. ECFA, 12 March, 2011, Vienna

2. Physics at -charm factory • Precision charm physics • Precision charm precision CKM (strong phases, fD, fDs ,form-factors…) • Unique source of coherent D0/D0bar states (D0 mixing, CPV in mixing, strong phases for f3 measurements at SuperB and LHC) • Precision -physics with polarized beams • Lepton universality, Lorentz structure of -decay… • CP and T-violation in t and c decays • LFV decays (t->mg) • Second class currents (with kinematical constraints at threshold) • High statistic spectroscopy and search for exotics • Charm and charmonium spectroscopy • Spectroscopy of the highly exited Charmonium states (complimentary to Botomonium) • Light hadron spectroscopy in charmonium decays

3. Advantages of near threshold production • Particle multiplicity at 3.77 GeV is about two times lower than at 10.6 GeV • Close to threshold the additional kinematical constraints can suppress combinatorial background ( useful for second class currents studies) • Two body production e+e-DD. This allows to use double tag method: • fully reconstruct one D • then either fully reconstruct the other D (absolute branching ratios) • or look for events with one missing particle (leptonic, semileptonic decays) • Coherent production of D pairs allows to use quantum correlations for D-meson mixing and CP violation studies

4. Polarization If even one beam polarized,  almost 100% longitudinally polarized near the threshold • CP-violation  new physics, charged Higgs • Two amplitudes with different weak and strong phases • Observables • Rate asymmetry: (+f+)-(-f)~sin sin • Triple product asymmetry (T-odd) (p1p2) T+-T-~cos sin • For complete description of matrix element , polarization and direction of  should be known • Polarization may increase sensitivity by several times Michel parameters CP-violation in -decays and/or LC

5. LFV decays Super-B, 75 ab-1 71010 -pairs •  decay • Current limit: ~ 310-8 by Belle with 7108  • At Y(4S): • ISR background e+e-+- • Upper Limit  1/L • tau-charm factory with 1010  will have better sensitivity

6. ISR Spectrum At near threshold • Egfor eettgbackground cannot be as high as Egfor tmg. • Background from eemmgwill become more important.  good MUID is essential. Eg (CMS) from tmg and ISR(ttg) U(4s) maximum s H.Hayahii 2008

7. Backgrounds • Combinatorial background from t+t- events • QED processes • Continuum background • Charm • Anything else? t(mnn)t(pp0n) 2E=3.77GeV t(mg)t(pn) Level of the sensitivity c/t factory to Br(t->mg)<10-9

8. Quantum correlated DDbar states • Quantum correlated DD state decay is a instrument for strong phase measurement in the hadronic D-meson decays • D mixing contribution to the KSπ+π– Dalitzplot distributions for even and odd DD states is different. It can be used for CPV and Mixing parameters measurement in the time integrated mode !

9. D mixing in time integrated mode at c/t Factory e/m+ K- e- e+ p- p+ g/p0 n Pure DD final state (ED(*) = Ebeam) Equal to Y(3770) cross-section of DD Low particle multiplicity ~6 charged part’s/event Good coverage to reconstruct nin semileptonic decays Pure JPC = 1- - initial state - Flavor tags (K-+ ,K-+ 0,K-+ -+), Semileptonic (Xe) KS e+e- -> KSπ+π–+ K+p –(CLEO-c)

10. MC Sensitivity (KSπ+π–+ K+l –n ) 1ab-1 s(xD)=1.3 10-3 s(fCP)=2.3 o If sensitivity of other states is comparable, the total statistical uncertainty should be 2-3 times better. s(yD)=0.9 10-3 s(|q/p|)=3.6 10-2

11. SuperB sensitivity

12. CLEOc Observation of e+e- -> hcp+p- Ryan Mitchell @ CHARM2010 Signal of Y(4260)→hc+- ?  Rate of Yb→hb+- is high?  Search for hb in (5S) data

13. CLEOc observation motivated Belle for hb search at Y(5S) Preliminary 2S1S 3S1S 121.4 fb-1

14. Technical specifications for Super c/t factory • Beam energy from 1.0 to 2.5 GeV • Peak luminosity is 1035 cm-2s-1at 2 GeV • Electrons are polarized longitudinally at IP • On-line energy monitoring (~5÷1010-5) Main features of the Super c/t factory design • Two rings with Crab Waist collision scheme and single interaction point • Sub-mm beta-y at IP • Preserving of damping parameters (by 4 SC wigglers) through the whole energy range to optimize the luminosity • 5 Siberian snakes to obtain the longitudinally polarized electrons for the whole energy range • Highly effective positron source (50 Hz top-up injection) • Polarized electron source • 2.5GeV full energy linac

15. Main ring schematically

16. Polarization degree vs energy

17. Luminosity betatron tune scan CW advantage: BB coupling resonances are suppressed Dn~0.2 is feasible Wide red area corresponds to 1035 cm-2s-1 Vertical tune Horizontal tune

18. Super factories accelerator challenges SB-INFN Similar (Nanobeam/CW) approaches yield similar problems in accelerator design All problems typical for Crab Waist/Nanobeam machines could be solved in collaborative manner by accelerator physicists

19. Photon Detectors SiPM Aerogel Tiles Detector ECL PID PID CDC m momentum range in t->mg TPC • Ultimate Hermeticity • PID e/m/p/K separation up to 2GeV/c • Momentum resolution • Low pT track efficiency • ECL energy resolution • Low energy (~20MeV) photons efficiency

20. Artistic view of future machine • Accelerator Complex 200 MEuro • Detector 80 MEuro • Buildings Construction and Site Utilities 50 MEuro

21. Project status and plans • CDR –in progress (to be ready in November 2011) • Collaboration is growing (now 10 Institutes from • Russia and 9 Institutes from other countries) • Design of the buildings –in progress (funded) • Injection complex - beginning of commissioning • Funding decision – end of 2012 ? • Construction 2012-2017?