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ITEP Winter School 2012, Feb 18 2012. Quarkonium, experiment. Roman Mizuk ITEP, Moscow. BELLE Collaboration. Contents. B-factories observed CP violation in B decays. Confirmed Kobayashi-Maskawa mechanism Nobel prize 200 8. Other highlights: many rare B decays D 0 mixing.
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ITEP Winter School 2012, Feb 18 2012 Quarkonium, experiment Roman Mizuk ITEP, Moscow BELLE Collaboration
Contents B-factories observed CP violation in B decays Confirmed Kobayashi-Maskawa mechanism Nobel prize 2008 Other highlights: many rare B decays D0 mixing Unexpected bonus : new exotic quarkonium(-like) states this lecture – experiment Mikhail Voloshyn – theory
X(3872) CP B→Xsγ 630 Belle citation count 548 365 Phys.Rev.Lett.91262001, (2003) 9th anniversary!
Outline Conventional quarkonium X(3872) 1– – family Charged states with bb pairs _
Heavy quarkonium Approximately non-relativistic Approximately non-relativistic _ _ _ _ _ “hydrogen atom” of QCD Rich array of bound states
Charmonium Levels M, GeV P = (–1)L+1 C = (–1)L+S S = s1 + s2 = {0, 1} J = S + L n – radial quantum number 4.50 (4415) 4.25 (4160) JPC (4040) c2(2P) 4.00 L=0 S=0 0– + c(1S), c(2S) (3770) J/ , (2S) , (4040) , (4415) 2M(D) 3.75 L=0 S=1 1– – c(2S) (2S) c2 hc c1 3.50 L=1 S=0 1+ – hc(1P) c0 0+ + 1+ + 2+ + c0(1P) c1(1P) c2(1P), c2(2P) 3.25 L=1 S=1 J/ c 3.00 L=2 S=1 1– – (3770), (4160) 2.75 (3770) = 13D1 + 0.2 23S1 n2S+1LJ 0– + 1– – 1+ – (0,1,2)++ JPC
Bottomonium levels • notation : • • subscript “c” ”b”
Observation of J/ BNL AGS extracted 28 GeV p-beam SLAC SPEAR e+e- annihilation Mark I first 4 detector Be target Richter et al. , nb , nb p + Be → e+e- + X Ting et al. , nb Width of t E c.m.s. JPC=1– – M( e+e- )
Observation of J/ Nov 1974 – revolution J/ is heavy and very narrow smth new Observation of 4th quark Quarks were widely recognized as particles Beginning of modern physics
c g g c e,m,q c g e,m,q ¯ ‾ ‾ ‾ c c c Why J/ is so narrow? C-parity 2/3 1/3 DD* D*D* ~as 3 DD at threshold For J/ strong decays are suppressed so much that EM decays are competitive.
Observation of family JPC of photon produced in e+e- collisions 1– – R = (e+e- hadrons) / 0(e+e- +-) 0= 42 / 3s
Observation of cJ and c (2S) cJ cJ J/ (2S) c E1 E1 M1 0– + 1– – (0,1,2)+ +
cJ c – DASP, DESY (1976)– Crystall Ball, SLAC (1980) Observation of Crystal Ball: sphere with 900 NaI crystals
Charmonium before B-factories 1980 – 2002 : no new charmonium states
Bottomonium before B-factories Lederman 1– – (0,1,2)+ + (1S), (2S) – 1977 FNAL pA collisions e+e- colliders: DORIS, DORIS-II (DESY) CESR (Cornell) VEPP-4 (Novosibirsk) 1985 – 2008 : no new bottomonium states
B-factories Data taking : 2000 – 2010 e+e– → (4S) Ecms ~ 10.6 GeV @ KEK @ SLAC
Charmonium production at B factories in B decays γγfusion c(2S) c2(2P) Any quantum numbers can be produced, to be determined from angular analysis. JPC = 0±+, 2±+ double charmonium production initial state radiation OnlyJPC = 0±+ observed so far. JPC = 1– –
Observation of hc(1P) CLEOc 2005 (c-Factory) (2S) hc(1P) 0 0 1– – 1+ –
QCD potential c J/ c2 (2S) Schrödinger equation one-gluon exchange, asymptotic freedom confiningpotential, “chromoelectric tube” There are other parameterizations, shapes are similar for 0.1 < R < 1 fm.
State Experim Predictions of Potential Models
Predictions of Potential Models M, GeV Potential models reproduce also annihilation widths J/y, y(2S)→ℓ+ℓ- hc, ccJ→ ggand radiative transitions btw. charmonia. JPC
pp collisions PRL91,262001 (2003) X(3872) was observed by Belle in B+ → K+ X(3872) (2S) → J/ψπ+π- X(3872) Confirmed by CDF, D0 and BaBar (+LHCb) Recent signals of X(3872) → J/ψπ+π- direct productiononly 16% from B PRL103,152001(2009) PRL93,162002(2004) arXiv:0809.1224 PRD 77,111101 (2008)
_ expect for cc ~20 Puzzles of X(3872) _ 2003 revolution Mass above DD threshold, but very narrow M = 3871.63 0.19 MeV , Γ < 1.2 MeV (90% C.L.) M = 3871.63 0.19 MeV , Γ < 1.2 MeV (90% C.L.) X(3872) → J/ψπ+π- +- pair is produced via 0 M(+-) X(3872) is observed in isospin-violating mode Bf(XJ/ ) / Bf(XJ/ ) = 0.8 0.3 confirm even C-parity Bf(XJ/ ) / Bf(XJ/ ) = 0.21 0.06 Mass close to D*0D0 threshold: m = – 0.09 0.34 MeV Very unlikely that X(3872) is charmonium
Exotic interpretations tetraquark molecule two loosely boundD mesons compact diquark-diantiquark state Maiani, Polosa, Riquer, Piccini; Ebert, Faustov, Galkin; … Tetraquark Predictions: Charged partners of X(3872). Two neutral states ∆M = 8 3 MeV,one populate B+ decay, the other B0. Experiment: BaBar, Belle :J/+0 channel no charged partner CDF :signal shape in J/+- channel no 2nd neutral resonances Belle :production in B+ and B0 decays Tetraquarks are not supportedby any experimental evidence.
Virtual state D0D00 J/+- Molecule Swanson, Close, Page; Voloshin; Kalashnikova, Nefediev; Braaten; Simonov, Danilkin ... Mass close to D*0D0 threshold: m = – 0.09 0.34 MeV _ JP = 1+ Weakly bound S-wave D*0D0 system a few fm Large isospin violation 8 MeV difference btw D*+D- and D*0D0 thresholds. _ Large production ratein ppand in B decaysadmixture ofc1(2P). _ Predicts different line shapes for J/+- and D*0D0 modes: Bound state J/+- D0D00 D*0D0
PRD77,011102(2008) B+& B0D0D*0K 4.9σ 347fb-1 arXiv:0810.0358 B KD0D*0 D*→Dγ D*→D0π0 605 fb-1 Flatte vs BW similar result: 8.8σ X(3872) → D*0D0 ~2 Bf(XDD*) / Bf(XJ/) = 9.5 3.1 Shifted mass and higherwidth are in accord with molecular model
Molecule (2) Bound or virtual? c1(2P) admixture? Simultaneous analysis of J/ and DD* data Braaten, Stapleton Zhang, Meng, Zheng arXiv: 0907.3167 0901.1553 Kalashnikova, Nefediev arXiv:0907.4901 ~2 experimental difference reverses conclusion Present statistics are insufficient to constrain theory
Angular analysis CDF, BELLE all JPC except 1++ and 2-+ are excluded cosqX MC JPC= 2-+ MC JPC=1++ cosqX cosc cosc cosql cosql cosqr cosqr
Nature of binding force One pion exchange ? Coupled channel resonance ? D D c1 c1 c1 D* D*
“Loose ends” _ Improve line-shape measurement for D*0D0 Super B-factories Angular analysis to discriminate JPC=1++ and 2 – + LHCb More decay channels : 00, +-c BELLE ?, LHCb, Super B-factories
c e+ e+ e+ γ • Use ISR to measure • open&hidden charm exclusive final states s =(Ecm– Eγ)2 – p2 e– e– e– c ISR at B factories • Quantum numbers of final states are fixed JPC = 1– – • Continuous ISR spectrum: • access to the whole √s interval • αemsuppression compensated by huge luminosity • comparable sensitivity to energy scan (CLEO-c, BES)
e+e– → ISR J/ () +- : Y(4008,4260,4360,4660) PRL99, 142002 670/fb PRL99, 182004 550/fb PRL98, 212001 298/fb arXiv: 0808.1543 454/fb – Above DD threshold, decayto open charm?
(e+e–→hadrons) R(s) = – Ruds (e+e–→μ+μ–) (4415) (4415) (4040) (4040) (3770) (3770) ψ(4160) ψ y ψ y (4160) ψ y 4325) 4360) 4008) 4008) y Y( Y( Y( Y( 4260) 4260) No evidence for Y’s → hadrons (4660) (4660) Y( Y( Y Y Durham Data Base ee is small. Since eeB(Y) is finite (is measured) B(Y) is big X.H. Mo et al, PL B640, 182 (2006) (Y(4260) → J/+-) > 0.508 MeV @ 90% CL Much larger than measured charmonium widths: (→ J/+-) = 0.044 ± 0.008 MeV (→ J/+-) = 0.104 ± 0.004 MeV
Interpretation – hybrid → D** D 1 – c π c π PRD80, 091101R (2010) DD* hybrid ψ(4415) Y(4260) state with excited qluonicdegree of freedom – → (D*π) D hadrocharmonium predictions? charmonium embeddedinto light hadron
DD DD* D*D* DDπ DD*π D(*)+s D(*)–s Λ+c Λ–c Inclusive cross-sectionis saturated byexclusive contributions
Charged resonances with bb _ (1S)+- (2S)+- (3S)+- hb(1P)+- hb(2P)+- Zb(10610)+- Zb(10650)+- (5S) arXiv:1103.3419 arXiv:1110.2251
Integrated Luminosity at B-factories (fb-1) asymmetric e+e- collisions > 1 ab-1 On resonance: (5S): 121 fb-1 (4S): 711 fb-1 (3S): 3 fb-1 (2S): 24 fb-1 (1S): 6 fb-1 Off reson./scan : ~100 fb-1 530 fb-1 On resonance: (4S): 433 fb-1 (3S): 30 fb-1 (2S): 14 fb-1 Off reson./scan : ~54 fb-1
e+e- hadronic cross-section BaBar PRL 102, 012001 (2009) (1S) (5S) (6S) (4S) (2S) (3S) (4S) Belle took data at E=108671MэВ 2M(B) 2M(Bs) _ e+ e- ->(4S) -> BB,whereBisB+orB0 _ _ _ _ _ e+ e- -> bb ((5S)) ->B(*)B(*), B(*)B(*)p, BBpp, Bs(*)Bs(*), (1S)pp, X … study
Puzzles of (5S) decays Anomalous production of (nS)+- PRD82,091106R(2010) (MeV) PRL100,112001(2008) line shape of Yb 102 (5S) Similar effect in charmonium? Y(4260) with anomalous (J/+-) assume Yb close to (5S) to distinguish energy scan shapes of Rb and () different (2) 41
Observation of hb(1P) & hb(2P)
Trigger CLEO observed e+e- → hc+– @ ECM=4170MeV (hc+–) (J/+–) PRL107, 041803 (2011) Y(4260) Hint of rise in (hc+-) @ Y(4260) ? 4260 Y(4260)Yb search for hb(nP)+- @ (5S) 43
Introduction to hb(nP) MM(+-) _ (bb) : S=0 L=1 JPC=1+- Expected mass (Mb0 + 3 Mb1 + 5 Mb2) / 9 MHF test of hyperfine interaction For hcMHF= 0.00 0.15 MeV, expect smaller deviation for hb(nP) Previous search arXiv:1102.4565 PRD 84, 091101 BaBar 3.0 (3S) → 0 hb(1P) 44
Introduction to hb(nP) MM(+-) _ (bb) : S=0 L=1 JPC=1+- Expected mass (Mb0 + 3 Mb1 + 5 Mb2) / 9 MHF test of hyperfine interaction For hcMHF= 0.00 0.15 MeV, expect smaller deviation for hb(nP) Previous search arXiv:1102.4565 PRD 84, 091101 BaBar 3.0 (3S) → 0 hb(1P) 45
(5S) hb +- reconstruction reconstructed * * M(hb) = Mmiss(+-) (Ec.m. – E+-)2 – p+- 2 hb → ggg, b (→ gg) no good exclusive final states “Missing mass” (1S) hb(1P) (2S) hb(2P) (3S) 46
Results 121.4 fb-1 Significance w/ systematics hb(1P) 5.5 hb(2P) 11.2 47
Hyperfine splitting Deviations from CoG (Center of Gravity) of bJmasses hb(1P)(1.7 1.5) MeV/c2 hb(2P)(0.5 +1.6 ) MeV/c2 consistent with zero, as expected -1.2 Ratio of production rates spin-flip for hb(1P) = for hb(2P) no spin-flip Process with spin-flip of heavy quark is not suppressed • Mechanism of (5S) hb(nP) +- decay violates • Heavy Quark Spin Symmetry 48
Resonant structure of (5S)hb(nP) +-
Resonant structure of (5S) hb(1P)+- phase-space MC M(hb–), GeV/c2 M(hb+), GeV/c2 50