1 / 59

The Structure and Dynamics

The Structure and Dynamics. of Hadron Systems. with two Heavy Quarks. Nora Brambilla (U. Milano). QCD and the Hadrons. Parameters:. ,. QCD and the Hadrons Structure. QCD and the Hadrons Dynamics. Bali et al. 95.

atara
Download Presentation

The Structure and Dynamics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The Structure and Dynamics of Hadron Systems with two Heavy Quarks Nora Brambilla (U. Milano)

  2. QCD and the Hadrons Parameters: ,

  3. QCD and the Hadrons Structure

  4. QCD and the Hadrons Dynamics Bali et al. 95

  5. Systems made by two quarks are golden systems for strong interactions • Precision determinations of QCD parameters (of interest for SM and BSM physics) • information on QCD vacuum and low energy properties (of interest for theories beyond QCD) • information on the transition region from high energy to low energy (of interest for the behaviour of perturbative series) They can provide us with:

  6. how is this?

  7. Low energy (nonperturbative) factorized effects depend on the size of the physical system

  8. Plan of the talk • Introduction • small systems,condensates,resummations and precise determinations • gluelumps, hybrids and condensates • inclusive decays, octets and factorization • Big systems,nonperturbative potentials and qcd vacuum models • “QQ” systems in baryons • challenges

  9. Quarkonium at the beginning • With the November 1974 revolution also the traditional quarkonium spectroscopy started: • huge impact: • c quark discovery; • asymptotic freedom; • confinement. • few conventional charmonium states; • limited production mechanisms; • limited statistics; • potential model.

  10. Progress based on New data New Theory

  11. (perturbative scale!) quark pair creation relevant only for light quarks and at large distances one channel is dominant

  12. QQ: a multiscale System and

  13. Multiscale Non-relativistic bound states No correlation between the number of gluons and the importance of the amplitude due to multiple scales; gauge dependence. In the Bethe-Salpeter approach great difficulties

  14. Nonrelativistic EFTs • Systematic expansion; • Model independent; Gauge invariant; • Factorization between high and low energy; • Only the relevant degrees of freedom remain dynamical (the rest integrated out in a controlled way); • All the relevant Fock components appear and with a power counting in v (e.g. octets) • Symmetries of the original theory constrain the c • Additional Symmetries of the system become manifest; • At the scale m the matching coeff. can be calculated in perturbation theory • Large logs can be resummed via RG.

  15. Disentangling scales with EFTs Hard Soft (relative momentum) Ultrasoft (binding energy) In QCD another scale is relevant

  16. EFTs for Quarkonium

  17. Poincare invariance of the EFT

  18. Constraints from Poincare Invariance Brambilla, Gromes, Vairo 03 In the same way one gets relations among the matching potentials V

  19. Small systems: QQ energies at • Summing large beta0 (removing the renormalon of the series) Beneke et al., Hoang et al.,Brambilla et al, Pineda • Summing the logs: RG correlated scales Luke and Savage; Manohar and Stewart; Pineda Soto low energy gluon singlet octet singlet perturbative singlet potential Dealing with the QCD perturbative series: The bottleneck are nonperturbative contributions: but they are suppressed ---> precision calculations are possible

  20. --Precise determinations of m_b and m_c --High order calculations of the static singlet QQbar potential (four loops NLL): full agreement with lattice --

  21. The Gluelump Spectrum

  22. QQ Static spectrum with gluons hybrid L a t t i c e Juge Kuti Mornigstar 98-06

  23. Gluelumps and hybrids in pNRQCD l a t t i c e Juge Kuti Morningstar 00 03 for small r pNRQCD applies Brambilla Pineda Soto Vairo 00

  24. Gluelumps and hybrids in pNRQCD: more symmetry! l a t t i c e Juge Kuti Morningstar 00 03 Brambilla Pineda Soto Vairo 00

  25. Gluelumps Masses Magnetic gluelump mass Electric gluelump mass is the fundamental object in many models of QCD vacuum Stochastic Vacuum Model, Dosch et al Dual QCD Baker et al Brambilla et al 97, 98,00

  26. Gluelumps Masses Magnetic gluelump mass Electric gluelump mass it gives also the leading nonperturbative correction to spectra and decay It needs better lattice calculation!

  27. Gluelumps Masses

  28. Inclusive decays

  29. Inclusive decays: perturbation and singlet model

  30. Inclusive decays: NRQCD Fock state content of QQbar in NRQCD:

  31. I n c l u s i v e d e c a y s pNRQCD factorization nonperturbative effects in condensates

  32. large systems

  33. Big systems: strongly coupled pNRQCD Brambilla Pineda Soto Vairo 00 • A potential (quark model like) description emerges from the EFT The QCD potential contains a hard and a soft part (in terms of Wilson loops) • V soft may be calculated on the lattice or in QCD vacuum models Creutz et al 82, Campostrini 85, Michael 85, Born et al 94, Bali et al 97k, Koma, Koma Wittig 2006, Brambilla et al 90 93 95 97, Dosch, Simonov: Baker et al

  34. Investigating the QCD vacuum All QQ dynamics is given in terms of Wilson loops and electric and magnetic insertion in the Wilson loop A QCD vacuum model is an assumption on the low energy behaviour of the Wilson loop (gauge invariant, all the rest follows)

  35. Studies of Confinement on Wilson loops/V_0 Bali et al Boryakov et al. 04

  36. QCD Spin dependent potentials -factorization; power counting; QM divergences absorbed by NRQCD matching coefficients

  37. Spin dependent potentials Such data can distinguish different models for the dynamics of low energy QCD

  38. Exact relations on the V’s from Poincare e. g. Gromes relation It is a check of the lattice calculation many other such relations in pNRQCD, Brambilla et al. 2003 Koma and Koma 2006

  39. QCD Spin independent potentials

  40. QQq and QQQ baryons

  41. Doubly Charmed Baryons Selex 02,04,06 but no confirmation by Focus and babar

  42. QQq systems Notice that diquark approximation not valid

  43. Hyperfine separation pNRQCD result L a t t i c e Selex data,Fig. from T. Cohen et al. See the internal QQ excitations ? state 3780 l>0? problems with e.m. transitions

  44. QQQ states The lowest QQQ states are few hundreds Mevs lower than Bjiorken’s Y. Jia 06

  45. Good testing bed for QCD vacuum models

More Related