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Marek Karliner

New States with Heavy Quarks. with B. Keren-Zur, H.J. Lipkin, J. Rosner and N. Tornqvist arXiv:1109.3472. Marek Karliner. From  to , BINP Novosibirsk, 20 Sep. 2011. Outline spin-spin interaction between quarks – “color magnetic” same constituent quark masses in mesons and baryons

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Marek Karliner

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  1. New States with Heavy Quarks with B. Keren-Zur, H.J. Lipkin, J. Rosner and N. Tornqvist arXiv:1109.3472 Marek Karliner From  to , BINP Novosibirsk, 20 Sep. 2011

  2. Outline • spin-spin interaction between quarks – “color magnetic” • same constituent quark masses in mesons and baryons • known baryons + mesons  predictions for • new heavy baryons: magnetic moments & masses • apps to heavy exotic QQqq mesons  predictions for Belle • Belle 5/2001: two Z_b(I=1) exotic mesons ~@ B+B*, B*+B* •  additional, more deeply bound states with I=0 BINP Novosibirsk, 20/9/2011

  3. å = M m i i Constituent Quark Models (CQM) • QCD describes hadrons as valence quarks in a sea of gluons and q-qbar pairs. • at low E, χSB •  quark constituent mass • hadron can be considered as a bound state of constituent quarks. • Sakharov-Zeldovich formula: • the binding & kinetic energies “swallowed” by the constituent quarks masses. BINP Novosibirsk, 20/9/2011

  4. Color Hyperfine (HF) interaction • 1st correction – color hyperfine (chromo-magnetic) interaction • A contact interaction • Analogous to the EM hyperfine interaction – a product of the magnetic moments. • In QCD, SU(3) generators take the place of the electric charge. BINP Novosibirsk, 20/9/2011

  5. Constituent Quark Model:caveat emptor • a low energy limit, phenomenological model • still awaiting derivation from QCD • far from providing a full explanation of the hadronic spectrum, but it provides excellent predictions for mass splittings and magnetic moments • assumptions: • HF interaction considered as a perturbation •  does not change the wave function • same masses for quarks inside mesons and baryons. • no 3-body effects. BINP Novosibirsk, 20/9/2011

  6. constituent quark mass ratios • example II: • extracting quark masses ratio: BINP Novosibirsk, 20/9/2011

  7. s s u u d d color hyperfine splitting in baryons • The Σ (uds) baryon HF splitting: • Σ*: total spin 3/2 - u and d at relative spin – 1 • Σ : isospin – 1 • Symmetric under exchange of u and d • u and d at relative spin – 1 • the ‘ud’ pair does not contribute to the HF splitting BINP Novosibirsk, 20/9/2011

  8. Quark mass ratio from HF splittings in mesons and baryons New type of mass relations with more heavy flavors BINP Novosibirsk, 20/9/2011

  9. Similar relation for bottom baryons  prediction for mass  (MK & Lipkin, hep-ph/0307243) BINP Novosibirsk, 20/9/2011

  10. new result from CDF at Hadron 2011: 193 MeV

  11. also prediction for spin splitting between and new result from CDF at Hadron 2011: 20 MeV BINP Novosibirsk, 20/9/2011

  12. Magnetic moments of heavy baryons •  mag. moments determined by s,c,b moments • quark mag. moments proportional to their • chromomagnetic moments • DGG: (=EXP) •  challenge to EXP ! BINP Novosibirsk, 20/9/2011

  13. Q Q Q Predicting the mass of baryons : Qsd or Qsu. (sd), (sd) in spin-0  mass given by Can obtain (bsd) mass from (csd) + shift in HF: BINP Novosibirsk, 20/9/2011

  14. MeV MeV several options for obtaining from data: • The Ξ (Qsq) baryons contain an s quark • Q mass differences depend on the spectator • optimal estimate from mesons which contain both s and Q: Q MeV BINP Novosibirsk, 20/9/2011

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  18. Predictions for other bottom baryons with B.Keren-Zur, H.J. Lipkin and J.L. Rosner : BINP Novosibirsk, 20/9/2011

  19. Work in progress: BINP Novosibirsk, 20/9/2011

  20. M.K. @DIS’09: “D0: Ω_b=6165 +/- 10 (stat) +/- 13(syst.) --- wrong” BINP Novosibirsk, 20/9/2011

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  25. Open challenges for color hyperfine interaction: • doubly heavy baryons: ccq, bbq • SELEX: huge isosplitting ccu-ccd =17 MeV !?... • b mass: Upsilon(1S)- b (BaBar, CLEO) • too large? BINP Novosibirsk, 20/9/2011

  26. a menage a trois is very different from an ordinary family… • similarly, exotic hadrons with both q-q and q-qbar pairs • have important color-space correlations that are completely • absent in ordinary mesons and baryons. • when both present, need to keep in mind that q-qbar • interaction is much stronger than q-q interaction • color structures that are totally different from those in • normal hadrons BINP Novosibirsk, 20/9/2011

  27. unusual experimental properties of • (Q Q qbar qbar) and (Q Qbar q qbar) tetraquarks • until 5/2011: • leading tetraquark candidate: X(3872) • Seen in • With very high stats by Belle, BaBar and CDF • M[X(3872)] = M(D) + M(D*) • = 1865 + 2007 to within 1 MeV! • b-quark analogue(s)? • TH: for sufficiently heavy Q-s, tetraquarks might be • below two meson threshold: • (b qbar bbar q) below B Bbar • (b qbar cbar q) below B Dbar BINP Novosibirsk, 20/9/2011

  28. crucial difference vs. ordinary mesons: can form a color configuration which has much stronger binding than some of these states have exotic electric charge, e.g.  their decays have striking experimental signatures: monoenergetic photons and/or pions, e.g. with I=0 above threshold can decay into via isospin violation, or electromagnetically into  both very narrow! BINP Novosibirsk, 20/9/2011

  29. _ _ Unique signal for bbqq and bbq double bottom baryons and bb tetratqaurks _ • b  c c s  J/ψ s so bbq  J/ψ J/ψ (ssq)  J/ψ J/ψΞ _ _ _ _ _ _ and bbqq similarly bbqq  J/ψ J/ψ (ssqq)  J/ψ J/ψ K K With all final state hadrons coming from the same vertex Unique signature but v. low rate. Challenge & opportunity for LHCb ! BINP Novosibirsk, 20/9/2011

  30. 2008: Belle reportedanomalously large BR (2 orders of mag.) 0802.0649 [hep-ph], Lipkin & M.K.: Enhancement due to mediation by tetraquark T_bb: B B*-bar  (b-bar b u dbar)

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  35. Alternative (complementary ?) desc. as “molecule” • Tornqvist, Z. Phys. C61,525 (1993): • Heavy-light Qq mesons have I=1/2 •  they couple to pions • deuteron-like meson-meson bound states, “deusons” • via pion exchange: • (I=0) at threshold  X(3872) ! • S-wave  • I=1 attraction x3 weaker than I=0  no I=1 • What about B B-bar* analogue ?... BINP Novosibirsk, 20/9/2011

  36. B B* vs D D*: • -- same attractive potential • -- much heavier, so smaller kinetic energy • expect and I=1 states near threshold • seen by Belle !!! • I=0 binding much stronger • I=0 states expected 40-50 MeV below threshold • EXP signature: • Z_b(I=0)  (ns) + - • Z_b(I=0)  B B-bar  via EM B*  B , E()=46 MeV •  LHCb! BINP Novosibirsk, 20/9/2011

  37. ? _b heavier, with I=1  stronger binding via   deuteron-like J=1, I=0 bound state: “beautron” exp. signature: (_b_b)  _b _b  (_b) = 4.3+-3 MeV, (_b) = 9.2+-3 MeV so might be visible should be seen in lattice QCD - + BINP Novosibirsk, 20/9/2011

  38. Summary • consitituent quark model with color HF interaction •  _b, _b, _b masses predicted to  3MeV • challenge for theory: derivation from QCD • prediction: • QQqq tetraquarks: new color structures, • unique exp. signatures • prediction for peaks  just seen by Belle • new I=0 exotic states below threshold: • BB*,B*B*,_b_b , … BINP Novosibirsk, 20/9/2011

  39. Backup slides BINP Novosibirsk, 20/9/2011

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  42. constituent quark mass differences • example I: quark mass differences from baryon mass differences: BINP Novosibirsk, 20/9/2011

  43. difference of effective quark masses is the same in in mesons and baryons but depends on the spectator quark “how much you weigh depends on who your neighbors are”  challenge to npQCD MK & Lipkin, hep-ph/0307243 BINP Novosibirsk, 20/9/2011

  44. Testing confining potentials through meson/baryon HF splitting ratioB. Keren-Zur, hep-ph/0703011 & Ann. Phys • from constituent quarks model can derive: • depends only on the confinement potential and quark mass ratio • can be used to test different confinement potentials BINP Novosibirsk, 20/9/2011

  45. Testing confining potentials through meson/baryon HF splitting ratio • 3 measurements (Q = s,c,b) • 5 potentials: • Harmonic oscillator • Coulomb interaction • Linear potential • Linear + Coulomb • Logarithmic BINP Novosibirsk, 20/9/2011

  46. Hyperfine splitting ratio from potential models vs experiment BINP Novosibirsk, 20/9/2011

  47. m( ) – m( ) independent of quark flavor (u,s,c,b) ! Effective meson-baryon supersymmetry • meson: Q qbar baryon: Q qq • in both cases: valence quark coupled to • light quark “brown muck” color antitriplet, • either a light antiquark (S=1/2) or a light diquark (S=0,S=1) • Effective supersymmetry: BINP Novosibirsk, 20/9/2011

  48. need to first cancel the HF interaction contribution to meson masses: • for spin-zero diquarks: • for spin-one diquarks need to also cancel HF contribution • to baryon masses: BINP Novosibirsk, 20/9/2011

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