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Stephen Lars Olsen Seoul National University February 10, 2014 A New Spectroscopy of Hadrons High-1 Gangwando
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Through a theorist‘s mind Visions of hadrons What is seen by an experimenter
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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
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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
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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 _
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The XYZ quarkonium-like mesons
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Charmonium spectrum Any meson that decays to a c and c quark should fit in one of the (gray) unassigned states.
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XYZ charmoniumlike mesons 1 +(-) 0 -+ 0 ++ 1 ++ Z c (3900) + 3899 ± 6 46 ± 22 1 +(-) Y(4260) ( J/ ) 0 -+ 0 +(+) /1 —(+)
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cc assignments for the XYZ mesons? _ no unassigned levels for the 1 - - 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 _ _
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the Y(4260) (e + e - hadrons) E cm (GeV) BaBar PRD86, 051102 M( + - J/ ) (GeV) found by BaBar in e + e - ISR + - J/
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Y(4260) + - J/ confirmed by Belle Belle PRL99, 182004 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, 101802 E cm (GeV) X. H. Mo et al., PLB 640, 182 e + e - hadrons
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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/
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_ Is there any anomaly in (4S,5S) (1S) ? “bottomonium” bb mesons 2M B = 10358.7 MeV ϒ (4S)
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(4S) + - (1S) ” (5S)” + - (1S) 2S 3S 4S (4S) (1S) + 477 fb -1 52±10 evts Belle: PRD 75 071103 Signal 23.6 fb -1 Belle: PRL 100 112001 325±20 evts parent N( + - (1S)) (Y 4S 1S ) theory (4S) 52 ± 101.75 ± 0.35 keV1.47 ± 0.03 keV “ (5S)” 325 ± 20590 ± 110 keV <1.5 keV Lum ~1/20 th σ ~1/5 th Signal ~×6 “5S” 4S 3S 2S
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“ (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-
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“ (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 ± )
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“ (5S)” - Z b1,2 + + (1,2,3S) (3S) (2S) (1S) M( (nS)π + ) max ++ 10,610 MeV 10,660 MeV Belle PRL 108, 122001 (2012) 121.4 fb -1
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J P of the Z b states
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19 Belle PRELIMINARY
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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, 122001 Summary of parameter measurements m B +m B* 2m B* March 2012 b d b d B B*
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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* ) = + 3.6 ± 1.8 MeV M Z b (106010) –2M B* = + 3.1 ± 1.8 MeV Slightly unbound threshold resonances?? M=10608.1 1.7 MeV =15.5 2.4 MeV M=10653.3 1.5 MeV =14.0 2.8 MeV PDG: M B + M B* = 10604.5 0.6 MeV M B* + M B* = 10650.2 1.0 MeV Belle: _ _
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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:1209.6450
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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? ???
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run BEPCII/BESIII as a Y(4260) factory Belle PRL99, 182004 BESIII: arXiv:1303.5949 (e + e - + - J/ ) = (62.9 1.9 3.7) pb e + e - ISR J/ Typical J/ + - e + e - + - J/ @E cm =4260 MeV Y4260 J/ ++ -- e+e+ e+e+
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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, 252001 Significance >8 ++ --
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Z c (3900) confirmed by Belle 26 Mass = (3894.5 ± 6.6 ± 4.5) MeV Width = (63 ± 24 ± 26) MeV Fraction = (29.0 ± 8.9)% (stat. err. only) Belle: PRL 110, 252002
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-- Mass = (3883.9 ±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, 022001 (last month) D* + D0D0 _ Significance >18 _
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J P of the Z c (3900)? e+ e- -- ZcZc J PC =? ? J PC =0 - initial state: final state: ZcZc 0-0- 0+0+ forbidden by Parity --- 0-0- 0-0- 0-0- 1+1+ flat 0-0- 1-1- J P =1 - J P =1 + J P =0 - The data clearly establish J P =1 + 1;±1 BESIII data
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Are there others?
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Study Y(4260) + - h c decays +-+- BESIII PRL 111, 242001 (2 months ago) sharp M( h c ) peak but not near ~3900 MeV M( ± h c ) c 16 channels hadrons
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Y(4260) + Z c (4020) - Mass = (4022.9 ±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, 242001 M( ± h c ) Fit results: = 4017.3 ±0.3 MeV 5.6 ± 2.8 MeV above D* 0 D* - thresh. Z c (4020) ++ -- -hc-hc hadrons
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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, 022001 4023 MeV BESIII arXiv:1308.2760 Mass = (4026.3 ± 2.6 ± 3.7) MeV Width = (24.8 5 ± 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*) _
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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 _
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molecules?
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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)
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Y(4260) X(3872)? is this from Y(4260) decays? X(3872) BESIII arXiv:1310.4101
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Y(4260) X(3872)? …cont’d BESIII arXiv:1310.4101 X(3872) Consistent with originating from the Y(4260) All cm energies combined: 6.3 ~20 evt signal
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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 _ _ _ _
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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?
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Back-up slides
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Event in the Belle Detector
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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
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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:
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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
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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 _
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Through a theorist‘s mind Visions of hadrons What is seen by an experimenter
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