Stephen Lars Olsen Seoul National University February 10, 2014 A New Spectroscopy of Hadrons High-1 Gangwando

Through a theorist‘s mind Visions of hadrons What is seen by an experimenter

multiquark states from diquarks & diantiquarks magenta anti-triplet  _ 3  _ 3 _ 3 yellow anti-triplet cyan anti-triplet d dd d d u u u u u u s s s s ss u s d d u s d H-dibaryon (anti-green)(anti-blue) (anti-red) red-blue diquark green-red diquarkblue-green diquark u u d d s Pentaquark _ u c c d tetraquark meson _ _ magenta-cyan-yellow color singlet 6-q state magenta-cyan-yellow color singlet 5-q state green-magenta color singlet 4-q state (anti-green) “exotic” hadrons that particle theorists love

multiquark states from “molecules” H-dibaryon u u d d s Pentaquark _ c u c d  _ _ D D*  u s d u s d  tetraquark meson   N K baryonium u u d u u d  p p _ _ _ _ _ “exotic” hadrons that nuclear theorists love

Non-qq mesons or non-qqq baryons predicted by `QCD-motivated’ models u c u c cc u d u s d _ _ _ _ u d u s d s _ u c u c _ _ _  D0D0 D* 0 _ pentaquarks glueballsH-dibaryon diquark-diantiquarkshybrids molecules _ Where are they?? non-qq & non-qqq color-singlet combinations _

The XYZ quarkonium-like mesons

Charmonium spectrum Any meson that decays to a c and c quark should fit in one of the (gray) unassigned states.

XYZ charmoniumlike mesons 1 +(-) Z c (3900) ± 6 46 ± (-) Y(4260)    (   J/  ) (+) /1 —(+)

cc assignments for the XYZ mesons? _ no unassigned levels for the Y (4260) & Y (4360) the X (3940) & X (4160) as the  c (3S) &  c (4S) would imply huge hyperfine splittings for n=3&4 the Y (3915) mass and  (Y   J/  ) are too high for the  c0 (2P). Also, no sign of Y  DD the (4) charged Zs must have a minimal quark content of ccud _ the X (3872) is a long complex story _ _

the Y(4260)  (e + e -  hadrons) E cm (GeV) BaBar PRD86, M(  +  - J/  ) (GeV) found by BaBar in e + e -   ISR  +  - J/ 

Y(4260)   +  - J/  confirmed by Belle Belle PRL99, Y (4260) peak in  (     J/  ) occurs at a dip in  (D (*) D (*) )   (     J/  ) is large, 10~100 × charmonium e + e -   ISR     J/  No sign of Y (4260)  D (*) D (*) M(  +  - J/  ) (GeV) BESII PRL88, E cm (GeV) X. H. Mo et al., PLB 640, 182 e + e -  hadrons

Is there a b-quark version of Y(4260)? BB BB * B*B*B*B* e + e -  hadrons E cm (GeV) e + e -  hadrons e + e -   +  - J/  e + e -   +  - ϒ (1S) ?  +  - ϒ (1S) e + e -      J/ 

_ Is there any anomaly in  (4S,5S)       (1S) ? “bottomonium” bb mesons 2M B = MeV ϒ (4S) 

  (4S)   +  -  (1S)  ”  (5S)”   +  -  (1S) 2S 3S 4S  (4S)   (1S)  +   477 fb -1 52±10 evts Belle: PRD Signal 23.6 fb -1 Belle: PRL ±20 evts parent N(  +  -  (1S))  (Y 4S   1S )  theory  (4S) 52 ± ± 0.35 keV1.47 ± 0.03 keV “  (5S)” 325 ± ± 110 keV <1.5 keV Lum ~1/20 th σ ~1/5 th Signal ~×6 “5S” 4S 3S 2S

“  (5S)”       (1S) ? Υ (1S)π + π - Υ (2S)π + π - Υ (3S)π + π - M2(π+π-)M2(π+π-) M2(ϒπ±)M2(ϒπ±) M2(ϒπ±)M2(ϒπ±) M2(ϒπ±)M2(ϒπ±) π+π-π+π- π+π-π+π-

“  (5S)”       (1S) ? M( ϒ (1S) π ± ) Υ (1S)π + π - Υ (2S)π + π - M2(ϒπ±)M2(ϒπ±) π+π-π+π- π+π-π+π- Υ (3S)π + π - M( ϒ (3S) π ± )

“  (5S)”   - Z b1,2 +   +  (1,2,3S)   (3S)   (2S)   (1S) M(  (nS)π + ) max ++ 10,610 MeV 10,660 MeV Belle PRL 108, (2012) fb -1

J P of the Z b states

19 Belle PRELIMINARY

Z b (10610) M=10608  2 MeV  =18.4  2.4 MeV Z b (10650) M=10653  2 MeV  =11.5  2.2 MeV Belle PRL 108, Summary of parameter measurements m B +m B* 2m B* March 2012 b d b d B B*

B-B* & B*-B* molecules?? B B* b b _ B-B* “molecule” B* b b _ B*-B* “molecule” _ _ __ Z b (106010) ± Z b (106050) ± M Z b (106010) –(M B +M B* ) = ± 1.8 MeV M Z b (106010) –2M B* = ± 1.8 MeV Slightly unbound threshold resonances?? M=  1.7 MeV  =15.5  2.4 MeV M=  1.5 MeV  =14.0  2.8 MeV PDG: M B + M B* =  0.6 MeV M B* + M B* =  1.0 MeV Belle: _ _

Z b (10610)  BB* & Z b (10650)  B*B* __ Z b (106010) ± Z b (106050) ± M(B*B*) _ M(BB*) _ “  (5S)”   - (BB*) + _ “  (5S)”   - (B*B*) + _ Bf(Z b (10610)  BB* Bf(Z b (10610)   + (bb) _ _ =6.1±0.4 Bf(Z b (10610)  B*B* Bf(Z b (10610)   + (bb) _ _ =2.8±0.4 Belle arXiv:

Are there c-quark versions of Z b ’s Is there a b-quark equivalent? Y(4260) discovered Yes, & it decays to Z b states Are there c-quark versions of Z b ’s? ???

run BEPCII/BESIII as a Y(4260) factory Belle PRL99, BESIII: arXiv:  (e + e -   +  - J/  ) = (62.9  1.9  3.7) pb e + e -   ISR     J/   Typical J/    +  - e + e -   +  - J/ cm =4260 MeV Y4260 J/  ++ -- e+e+ e+e+

Y(4260)   - Z c (3900) +   + J/   Mass = (3899.0±3.6±4.9) MeV  Width = (46±10±20) MeV  Fraction = (21.5±3.3±7.5)% BESIII: PRL 110, Significance >8  ++ --

Z c (3900) confirmed by Belle 26 Mass = ( ± 6.6 ± 4.5) MeV Width = (63 ± 24 ± 26) MeV Fraction = (29.0 ± 8.9)% (stat. err. only) Belle: PRL 110,

--  Mass = ( ±1.5 ±4.2) MeV  Width = (24.8 ±3.3 ±11.0) MeV  DD*/     J/  = 6.2 ± 1.1 ± 2.7 Y(4260) ZcZc  DD* Y(4260)   - Z c (3900) + DD* _ D 0 D* + D + D* 0 _ _ _ BESIII PRL 112, (last month) D* + D0D0 _ Significance >18  _

J P of the Z c (3900)? e+ e- -- ZcZc J PC =? ? J PC =0 - initial state: final state:  ZcZc forbidden by Parity flat J P =1 - J P =1 + J P =0 - The data clearly establish J P =1 + 1;±1 BESIII data 

Are there others?

Study Y(4260)   +  - h c decays +-+- BESIII PRL 111, (2 months ago) sharp M(  h c ) peak but not near ~3900 MeV M(  ± h c )  c 16 channels  hadrons

Y(4260)   + Z c (4020) - Mass = ( ±0.8 ±2.7) MeV Width = (7.9 ±2.7 ±2.6) MeV fraction = 0.18 ± 0.07 no significant signal for Z c (3900) ±   ± h c BESIII PRL 111, M(  ± h c ) Fit results: = ±0.3 MeV 5.6 ± 2.8 MeV above D* 0 D* - thresh. Z c (4020) ++ --  -hc-hc hadrons

Does the Z c (4020)  DD*? … D*D*? _ _ Z c (4020)  DD*? _ D 0 D* + D + D* 0 _ _ 4023 MeV No sign of Z c (4020)  DD* _ BESIII PRL 112, MeV BESIII arXiv:  Mass = ( ± 2.6 ± 3.7) MeV  Width = ( ± 5.6 ± 7.7) MeV Fit results: Something there (~10  !), but … … higher mass (~1.5  ) and width (~1.5  ) than Z c (4020)   h c signal Z c (4020)  D*D*? _ M(D*D*) _

Z b & Z c mesons --“smoking guns” for non-qq mesons-- u b d b  decay to  (nS) (J/  )  must contain bb (cc) pair  electrically charged  must contain ud pair _ _ _ b b b b B0B0 B *+ d d B 0 -B *+ ? ? Mixture? u c d c ZbZb ZcZc _

molecules?

CMS search for b-sector version of X(3872) CMS: PLB 727 (2013) 57 (M B + M B* )-M  (1S) = 1144 MeV >> m  (M D 0 + M D* 0 )-M  (1S) = 776 MeV < m  Relevant channel is ispin-conserving X b    (1S)

Y(4260)   X(3872)? is this from Y(4260) decays? X(3872) BESIII arXiv:

Y(4260)   X(3872)? …cont’d BESIII arXiv: X(3872) Consistent with originating from the Y(4260) All cm energies combined: 6.3  ~20 evt signal

Summary  QCD-motivated spectroscopies most favored by theorists do not seem to exist - evidence for Pentaquarks has disappeared - H-dibaryon with mass near 2m  is excluded at stringent levels  Numerous non-qq mesons not specific to QCD have been found - Baryonium in J/    pp at BESII and BESIII ?? - XYZ mesons containing cc and bb pairs  The J PC =1 - - Y(4260) and “  (5S)” have no compelling interpretation - huge couplings to     J/      (nS))  not predicted in any model!! - strong sources of charged Z c (Z b ) states with M near m D ( * ) +m D* (m B ( * ) +m B* ) - evidence for a strong Y(4260)   X(3872) transition _ _ _ _

Y(4360) Y(4660) Y(4260) Y(4008) X(3872) X(4160) Y(3915) Z(4430) Z 1 (4050) Z 2 (4250) Z c (3900) Y(4140) Z b (10610) Z b (10650) Y(4274) X(3940) X(4250) X(4630) Lots of pieces Are they all from the same puzzle?

Back-up slides

Event in the Belle Detector

The “XYZ” mesons Z b1 (10610) 10,607±2 18±2 1 -  ± ϒ (1,2,3S)/h b (1,2S); BB* ` ϒ (5S)’   ± Z b1 Z b2 (10650) 10,653±2 12±2 1 -  ± ϒ (1,2,3S)/h b (1,2S);B*B* ` ϒ (5S)’   ± Z b2

43 “Old” hadron spectrosopy 1964 The constituent quark-parton model was proposed independently by Gell-Mann and Zweig. Three fundamental building blocks 1960’s (p,n, )  1970’s (u,d,s) mesons are bound states of a of quark and anti-quark: baryons are bound state of 3 quarks:

QPM Superseded by QCD in the 1970s: observed particles are color singlets 44 Λ = (uds) Mesons are color-anticolor pairs Baryons are red-blue-green triplets 3 primary colors  white color + complementary color  blue-yellow green-magenta red-cyan

QCD “diquarks” ?  s u d = s u d u  _ 3 antisymmetric anti 3-plet du ud - sd ds - su us - dduu ss du ud + sd ds + su us + symmetric 6-tet 6 3  3 = 3  6 _

Through a theorist‘s mind Visions of hadrons What is seen by an experimenter