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Charm physics at Super B factories

Charm physics at Super B factories. P. Pakhlov (ITEP, Moscow). On the need for a Super-tau-charm-factory. Budker INP, Novosibirsk, September 27, 2008. Flavour Physics at B-factories.

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Charm physics at Super B factories

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  1. Charm physics at Super B factories P. Pakhlov (ITEP, Moscow) On the need for a Super-tau-charm-factory Budker INP, Novosibirsk, September 27, 2008

  2. Flavour Physics at B-factories Great results by PEPII and KEKB BFactories. In 2001 Babar and Belle have discovered CP violation in B sector sin2β0; • Now β is measured with 1° accuracy. • α and γare measured with 10° accuracy. • Many other CP violating channels including b→sqq • Direct CP violation in B decays • Rare B decays (B→τυ; B →K(*)ll) • Observation of DD mixing • New particles: • Excited charm mesons and baryons; • Charmonium like states

  3. Charm physics goal I Not automatically reached by increasing the statistics Precision test of the SM (over constrain CKM together with B-physics) Fundamental parameters: mc; |Vcs|; |Vcd| Cancellation of QCD uncertainties: fB ; B→ form factors Inputs for CPV fits in B-decays: absolute Br’s; resonant structures in D decays; phases of Dalitz plot We dream to have this in 5-10 years 50 ab-1

  4. Charm physics goal II D0D0 mixing Unfortunately, the only clear signature of NP in D-mixing (x >> y) is hardly realized in nature: Experiment: x ~ y ~ 1% Search for New Physics CP violation • Large room for hunting of NP (could be ~1%); • Direct CPV in CF & DCS decay: requires New Physics • Direct CPV in SCS decay expect O(4) ~ 10 −3 from CKM matrix • Indirect CPV Rare decays At least for some modes UL constrain the NP parameters

  5. Charm physics goal III Understanding of QCD Charm hadrons production Potential models Exotic states • large cross sections • e+e–J/ D(*+) X • e+e–J/ ηc >10 new charmonium-like states – are they conventional cc-bound states? M(p+y(2S))

  6. e+e– machines at Y(4S) 36 35 34 33 32 2020 2010 1995 2015 1985 2005 2000 1990 cc cross section 1.3 nb (+ charm production from B decays Br(B→Hc)=110%) cc → D0 / D+ / Ds+ / Λc+ / J/ψ = 1.2 / 0.45 / 0.22/ 0.12 / 0.001 Log(L) SuperB SuperKEKB KEKB+Belle PEP+BaBar CESR+CLEO DORIS+ARGUS B-factory B-superfactory B-manufactory year

  7. Charm decay constants & FF with LQCD • No free parameters: αs, mu, md, ms, mc are fixed from other inputs. • mDs, mD, f, fK give consistency check.

  8. fD from experiment D(s) ,K  γ  424pb-1 fDs fD B-factories: tag D* → D(,γ) → lυ by recoiling D and fragmentation; c-factories: reconstruct one Ds(*) at the maximum of e+e−→ Ds*Ds x-section. Add lepton and compute missing mass 548 fb-1

  9. Semileptonic decays D ,K +slow  D0 D0→Kl +ν  e D0→l +ν • Vcs (Vcd) from DK()l • Form-factors to constrain Vub (Dl vs Bl assuming HQET) B-factories: tag D*+ → slowD→ lυ by recoiling D and fragmentation; • Good q2 resolution • Dl/DKl separation using kinematics D0→Kl D0→l mn² GeV²

  10. Rare decays: leptonic D0→ reference μ c D0→ 4 evts q u μ • SM expectation 4×10-13; • SUSY: 10-6 • BaBar (122 fb-1) 1.3×10-6 (2004) • CDF (360 pb-1) 5.3×10-7 (this year) Super B factories can do this better than c-factories, but hadronic machines can do this as well

  11. Rare decays: D →Mll • Loop contribution GIM suppressed; • SM largest contribution is due to V→ll decays ~ 10-6 • Present experimental sensitivity: ULs 10-4−10-6 • Distinguish NP from SM with dilepton mass spectrum or/and FB asymmetries Forbidden: Lepton flavour (number) violation D0 → e  (< 8.1 × 10-7 BaBar); D+ → K+ e  (< 3.7 × 10-6 BaBar) D+→ − e+ e+(< 3.6 × 10-6 CLEO-c)

  12. Rare decay: radiative K* helicity distribution is different from main bg Belle (2004) 87 fb-1 Short distance FCNC decay is tiny Long distance effect dominates: A(Vector Meson Dominance) ~ A(pole diagram) + interference Br ~ 10-4− 10-6 BaBar (2008) 387 fb-1 Br(D0→)=(2.60.70.2)10-5 Br(D0→K*γ)=(3.22±0.20±0.27)10-4 Br(D0→γ)=(2.73±0.30±0.36)10-5

  13. Charm decay summary • We do not discuss DD mixing and CP violation here (Bostjan’s talk) • Pure and semileptonic decays for fD and FF: Super B factory (L=1036 ) can do this, but Super charm-factory (L=1035 ) can do this much better. • Rare decays: Super B factory (L=1036 ) can set the best UL for almost all the channels because of the largest D statistics. LHC can probably compete in D0→μμ. • Interesting channels, that are problematic for B factories: • D0→KL for δK • CP tagged Dalitz analysis D0→KS 

  14. New charmonia y(2S) → p0hc→ p0ghc • B(KSK)K Belle, 2002 M=(3524.4±0.6±0.4) MeV/c2 M=(265410) MeV/c2 <55MeV CLEO, 2005 e+e- J/c(2S) c(2S) M=(263012) MeV/c2 Belle, 2002 Charmonium table below DD threshold is complete!

  15. Phys.Rev.Lett. 91 262001 (2003) X(3872) – the first in “X” series, X(3872) N/10MeV M(p+p–ℓℓ)- M(ℓℓ) GeV 3.5σevidence NEW B0→XK0s B±→XK± X(3872)→(2S)γ introduces a new particle naming scheme: X, Y, Z ... Belle, 2003 Everything is surprising: • Observed in the decay B+(J/)K+ • MX=(3872.00.60.5) MeV/c2in close vicinity of D0 D*0 threshold: • well above DD threshold but narrow: • unnatural spin-parity? In this case X→χcγ should be strong, not seen in the data. • decay dynamics:M+- tends to peak around limit (J/ 0 is isospin violating decay) MX – MDD* = (–0.4  0.7) MeV/c2 (PDG’07) • X decays to J/y g, but very rarely (Belle 2004, BaBar 2006). This observation fixes CX=+1, and confirms that in the X→J/ypp decay (pp)=r. • X decays to y(2S) g, slightly more often (BaBar this year) • X decays to J/y w with Br ~ Br (X→J/ypp), confirms isospin violation. • Fit to M(pp) favours L=0  PX= +1. <2.3MeV at 90% C.L. Br(X→J/γ) / Br(X→J/ π+π–) = 0.19 ± 0.07 Br(X→(2S)γ) / Br(X→J/π+π–) = 1.1 ± 0.4 M(p+p–)

  16. Fixing quantum numbers & more decay channels B KD0D*0 D*→Dγ Preliminary D*→D0π0 605 fb-1 Flatte vs BW similar result: 8.8σ Belle, 2004 CDF, 2006 Angular analysis • JPC=1++ corresponds to c1΄(23P1): • c1΄→ J/ should be much stronger than c1΄→ J/ (measured ratio ~0.2, expected ~30) • ~100MeV/c2 lighter than expected. JPC=2–+ corresponds to c2(11D2): • is expected to decay into hadrons rather than into isospin violating mode. • If X(3872) is virtual state, Flattè-like coupled channel effect • X→J/ψpp– the DD* threshold cusp with a sharp maximum at MD0 + MD*0 • X→D0D0p0 – peak shifted by few MeV off MD0 + MD*0 Hanhart,Kalashnikova, Kudryavtsev,Nefediev

  17. Options for X(3872) c D*0 r,w,... u ¯ D0 u ¯ c ¯ • - Voloshin-Okun JETP Lett. 23, 333 (1976): discuss existence of molecular-like states when mc→ • De Rujula-Georgy-Glashow PRL, 38, 317 (1977) apply to y(4040) • the idea was abandoned for many years • X(3872) enigmatic properties flashed back to the early ideas: Close-Page; Voloshin; Swanson; Tornqvist supposed that X(3872) is a • D0D*0 molecular state: • MX ~ MD0 + MD*0 is not occasional • JPC=1++ has been predicted (D0D*0 in S-wave) • Isospin violation has been expected: • MD– + MD*+ is by  ~ 8 MeV higher;  >> binding energy • Small X(3872) → J/y g has been expected • Absolute winner by popularity: > 50% of theoretical papers consider molecular model • Other options: • Tetraquark (cq)(cq): predicts three states (cu)(cu), (cd)(cu), (cd)(cd) with a few MeV mass splitting between them. • Hybrid (ccg) state. • Threshold cusp (not in contradiction to the molecular model) MX ~ MD0 + MD*0 is occasional?

  18. More states arXiv:0711.2047 M = 3942 ±6 MeV tot =37 ±12 MeV +7 -6 +26 - 15 PRL96,082003(2006) c2′=23P2→DD +25 −20 M= 4156 15 MeV tot = 139 21 MeV 5.3σ +111 −61 B →Y(3940)K Some are identified (c2′), but M contradicts to potential models For most of other the QN are unknown but in any case there is a contradiction to the predicted masses Confirms Belle PRL100, 20200 (2008) B0→Y(3940)K0S 6.0 X(3940) → DD* 5.5 X(4160) → D*D*

  19. eeJ/ & ee’ via ISR g e– e+ e– s=(Ecm-Eg)2-pg2 (2S) 1–– final state Belle: confirms BaBar +low mass enhancement Belle: confirms BaBar +higher mass peak • Peak positions in J/ & (2S)significantly different. • There is no place in the 1– – charmonium spectrum even for one state...

  20. σ(e+e–→open charm) via ISR Belle: Sum of all measured exclusive contributions (3770) (4160) Y(4008) Y(4350) (4415) Y(4260) Y(4660) (4040) NEW Durham Data Base if Ruds=2.285±0.03 helpful for understanding of Y? PRD77,011103(2008) DD ? • Y(4260) mass corresponds to dip in D*D* cross sect. • Y(4350) ... • Y(4660) mass is close to Λc+Λc–peak • Enhancement near 3.9 GeV in ee→DD coupled channel effect? DD* (4160) Y(4350) PRL98, 092001 (2007) Y(4008) D*D* Y(4260) (4415) (4040) PRL100,062001(2008) Y(4660) DDπ arXiv:0807.4458 Λc+Λc– ICHEP2008

  21. B → KZ,Z(4430)+→ p+y(2S) K=K–,K0s ;(2S)→ℓ+ℓ–, p+p-J/y Z(4430)+ first charged charmonium like state ??? Preliminary M2((2S)), (GeV2 ) 4430 K*(892)+K*(1430) K*(1430) K*(890) K*(892)+K*(1430) veto M2(K), (GeV2 ) M((2S)), (GeV ) 548 fb-1 PRL 100, 142001 (2008) K*(892)+K*(1430) veto • M = (4433±42) MeV • = (45+18-13+30-13) MeV 6.5  Br(B→ZK)×Br(Z→y(2S)p) = (4.1±1.0±1.3) 10-5 Br(B0→ZK+)×Br(Z→ψ(2S)π)<2.6x10-5at 95% CL M(p+y(2S))

  22. More Z+s(→χc1π+) arXiv:0806.4098 ??? M2(χc1π), (GeV2 ) K*(1680) K*(1780) K*(1430) K*(890) M2(K), (GeV2 ) • B0→χc1π+K–;χc1 →J/ψγ • Dalitz analysis: fit B0→χc1π+K– amplitude by coherent sum of RBW contributions • all known Kπ resonances (including κ) • K*’s + one (c1) resonance • K*’s + two (c1) resonances M1=(4051±14+20–41) MeV/c2 Γ1=(82+21–17+47–22) MeV M2=(4248+44–29+180–35) MeV/c2 Γ1=(177+54–39+316–61) MeV • Hypothesis of two Z’sresonances is favored over one Z resonance at 5.7  • Spin of Z1,2 isnot determined: J=0 and J=1 result in comparable fit qualities two Z’s without Z’s Cannot be conventional charmonium or hybrid Z1 Z2

  23. Placed here by JPC Y(4660) (4415) Z+(4440) Y(4350) X(4160) (4160) Z+(4250) Y(4260) χc2’ Z+(4050) Y(3940) (4040) X(3940) X(3872) (3770) ’ h’c χc2 χc1 hc χc0 J/ hc M(MeV) DD JPC

  24. Charmonium summary (2S) Molecule? Hybrid? Tetraquark? • Charmonium below DD threshold have all been seen • All new (neutral)charmonium(like) states above DD threshold are at “wrong” masses. Some of them have “wrong” decays modes. Some are “wrongly” produced… • Are all peaks necessarily a state? • Do we need exotic explanation to solve all these problems? • Can we solve all the problems at once? BaBar has been stopped, Belle will be stopped soon… Most of questions have to wait for Super B factories

  25. Double charmonium production • Look at the recoil mass against reconstructed J/ using two body kinematics (with a known initial energy) Mrecoil = (Ecms- E J/ )2 - P J/2 ) • See all the (narrow) states produced together with J/y. • The data shows unexpectedly charmonia states: hc, cc0, hc(2S) • Note: all recoil states are 0±+. • The cross sections are ~10 times larger than expected Belle(2002) BaBar (2005) experiment ~10*theory

  26. New states observation potential 36 35 34 33 32 2020 2010 1995 2015 1985 2005 2000 1990 90% PDG’s charm tables is filled by B-machines Λc(2593) Λc(2625) Λc(2880) Λc(2760) Ξc(3070) Σc(3070) Λc(2940) Ωc Ξc‘ Ωc’ ? ? ? ? ? Log(L) Ds2*(2517) Ds1(2530) Ds1(2420) Ds?(2700) D2*(2460) D0*(2400) Ds0(2317) D1(2420) D1(2430) SuperB SuperKEKB KEKB+Belle PEP+BaBar CESR+CLEO B-superfactory DORIS+ARGUS B-factory B-manufactory year

  27. Summary • Besides the main goal of hunting/constrain New Physics in B sector (precise CPV rare decays), Super B factories have a great potential to obtain interesting results in charm physics: charm decays, DD-mixing, charm(onium) spectroscopy, production. • The charm physics programs at Super B and Super charm-tau factories are complimentary. T H A N K Y O U

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