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New Theoretical Approaches to Heavy Flavor Suppression

New Theoretical Approaches to Heavy Flavor Suppression. A. Adil and I.V., hep-ph/0611109, H. van Hees I.V. and R. Rapp, in progress. Ivan Vitev, T-16 and P-25, LANL. Energy loss in QCD – application to light / heavy hadrons Implementation in heavy quark diffusion simulations

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New Theoretical Approaches to Heavy Flavor Suppression

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  1. New Theoretical Approachesto Heavy Flavor Suppression A. Adil and I.V., hep-ph/0611109, H. van Hees I.V. and R. Rapp, in progress Ivan Vitev, T-16 and P-25, LANL • Energy loss in QCD – application to light / heavy hadrons • Implementation in heavy quark diffusion simulations • Alternative theory of heavy flavor suppression in the QGP • Conclusions

  2. Light Hadron Quenching in A+A Establishing the E-loss mechanism • Radiative: Very important: Laldau-Pomeranchuk-Migdal effect Important: mass dependence • Collisional: I.V., Phys.Lett.B 639 (2006)

  3. Non-Photonic Electron / Heavy Flavor Quenching • Single electron measurements (presumably from heavy quarks) may be • problematic M.Djordjevic, M.Gyulassy, Nucl.Phys.A (2004) • Radiative Energy Loss using (D)GLV • (both c + b) • Radiative + Collisional + Geometry • (both c + b) (overestimated) • Deviation by a factor of two • Is it accidental or is it symptomatic? S. Wicks et al., nucl-th/0512076

  4. - drag ~ - diffusion ~ Langevin Simulations of C- / B-Quark Diffusion • Model of quark-resonance interaction • near the QCD phase transition Fokker-Plank diffusion equation • Expansion of gain / loss terms tosecond • order Equilibration is imposed by Einstein’s fluctuation-dissipation relation: H. van Hees, R. Rapp, Phys.Rev.C71 (2005) • Efficient at • Include e-loss at high pT

  5. Collisional versus Radiative Energy Loss Input in a Langevin simulation of heavy quark diffusion • Drag coefficient: H. van Hees, I.V., R. Rapp, in preparation • Diffusion coefficient: Two regimes (light partons): Radiative energy loss is dominantexcept for b-quarks and very small systems

  6. Transport + Quenching Approach Numerical results for heavy quark diffusion Results arepreliminary H. van Hees, I.V., R. Rapp, in preparation • The suppression and v2 are large when e-loss and q-resonance interactions are • combined • Normal hierarchy: c quarks are significantly more suppressed than b-quarks

  7. Hadron Parton QGP extent B D 20 fm 0.4 fm 1.5 fm Conceptually Different Approach to D / B • Problem: treated in the same way as light quarks + • Fragmentation and dissociation of hadrons from heavy quarks inside the QGP C.Y.Wong, Phys.Rev.C 72, (2005)

  8. Light Cone Wave Functions …and their distortion • Heavy meson acoplanarity • Distortion of the light cone wave function • (meson decay) • Distribution of internal momenta S.Brodsky, D.S.Hwang, B.Q.Ma, I.Schmidt, Nucl.Phys.B 592 (2001) A.Adil, I.V., hep-ph/0611109

  9. Heavy Meson Dissociation at RHIC and LHC Coupled rate equations A.Adil, I.V., hep-ph/0611109 • The asymptotic solution in the QGP - • sensitive to t0~0.6 fm and expansion • dynamics • Features ofenergy loss • B-mesons as suppressedas D-mesons • at pT~ 10 GeV (unique feature)

  10. Similar to light , however, • different physics mechanism Quenching of Non-Photonic Electrons A.Adil, I.V., hep-ph/0611109 • PYTHIA used to decay all B- and • D-mesons / baryons into (e++e-) • SuppressionRAA(pT) ~ 0.25is • large • B-mesons are included. They give • a major contribution to (e++e-) • Predictions also made for Cu+Cu (RHIC) and Pb+Pb (LHC)

  11. Summary of Open Heavy Flavor Suppression • Langevin simulation of heavy quark diffusion • Calculated drag and diffusion from the collisional and radiativee-loss • Combined with a chiral model of quark-resonance interactions: obtained large v2and RAA .Work in progress • Normal suppression hierarchy: B- much less suppressed than D- mesons • Collisional QGP-induced B- / D-meson dissociation • Derived formation and dissociation times in the QGP. They are short • Solved the set of coupled rate equations. Moresensitive to QGP • properties and formation / expansion dynamics than e-loss • Found that suppression of non-photonic electrons from heavy mesons, • including B, is large. Not inconsistent with light pions • B-mesons are as suppressedasD-mesons at pT ~ 10 GeV,unique • Toward experimental resolution of the B- / D- puzzle • Identify the B- and D-mesoncontribution to the inclusive electron spectra • and the suppression factor RAAseparatelyforBsandDs

  12. Outline of the Talk Based upon: I.V., work in progress A.Adil and I.V., hep-ph/0611109 H. van Hees I.V. and R. Rapp, work in progress • Energy loss in QCD • Radiative and collisional energy loss, recent developments • Application to A+A collisions and p+A collisions • Applications to heavy quarks • Discrepancy between PQCD and c- and b-quark quenching • Transport+quenching approach to D- and B mesons • Alternative theory of heavy flavor suppression • In-medium formation and dissociation of D- and B- mesons • Suppression of non-photonic electrons • Conclusions

  13. Types of Energy Loss • Collisional: Arises from the acceleration of the charges in the target. No significant mass dependence • Radiative: Arises from the acceleration of the incident charge. Can have significant mass dependence Much more efficient

  14. Understanding the LPM Effect • Bremsstrahlung is the most efficient way to lose energy since it carries a fraction of the energy LPM • Formation time:coherence effects • Acceleration:radiation • Full coherence • Onset of coherence

  15. Regimes of QCD Radiative Energy Loss • Bertsch-Gunion Energy Loss • Initial-State Energy Loss • Final-State Energy Loss I.V. in preparation

  16. Light Hadron Quenching in A+A Establishing the E-loss mechanism Theory (constrained) / Experiment C.M. energy Centrality D. d’Enterria, Eur.Phys.J C (2005) I.V., Phys.Lett.B 639 (2006)

  17. Nuclear Effects at Forward Rapidity • Dynamical shadowing (FS) • Cronin effect (IS) • Initial state energy loss (IS) • Consistency in the extracted cold • nuclear matter properties I.V., in preparation • The most detailed calculation so far at forward rapidity

  18. 2 Correlated! x What Happens to Medium-Induced Radiation? In A+A +2Re • Cancellation of collinear radiation I.V., Phys.Lett.B630 (2005) First quantitativePQCD calculation How about p+A?

  19. I. Heavy Ion Theory Effort at LANL Core theory staff • Terry Goldman (T-16, quark models, neutrinos, PQCD) • Rajan Gupta (T-8, energy future, LQCD) • Mikkel Johnson (P-25, energy loss, shadowing, PQCD) • Emil Mottola (T-8, gravity, black holes, non-equilibrium FT) J.Robert Oppenheimer fellow • Ivan Vitev (P-25& T-16, energy loss, shadowing, PQCD) • External Collaborators • Miklos Gyulassy (Columbia U.) • Boris Kopeliovich (Heidelberg U., Germany) • Peter Levai (KFKI, Hungary) • Jianwei Qiu (Iowa State U.) • Joerg Raufeisen (Heidelberg U., Germany) • Ivan Schmidt (Santa-Maria U., Chile) Collaborating institution Columbia university

  20. Publications and Workshops • Publications. • Ivan Vitev, LARGE ANGLE HADRON CORRELATIONS FROM MEDIUM- INDUCED GLUON RADIATION. • Phys.Lett.B630:78-84,2005. • Ivan Vitev, T. Goldman, Mikkel Johnson, Jian-Wei Qiu, NUCLEAR EFFECTS ON OPEN CHARM PRODUCTION IN • P+A REACTIONS. HEP-PH 0511220 • Ivan Vitev, JET QUENCHING AT INTERMEDIATE RHIC ENERGIES. Phys.Lett.B606:303-312,2005. . • Mikkel B. Johnson, PROPAGATION OF FAST PARTONS IN THE NUCLEAR MEDIUM. Eur.Phys.J.A19:2004. • B.Z. Kopeliovich, J. Nemchik, I.K. Potashnikova, M.B. Johnson, I. Schmidt, BREAKDOWN OF QCD • FACTORIZATION AT LARGE FEYNMAN X. Phys.Rev.C72:054606,2005. • Fred Cooper, Ming X. Liu, Gouranga C. Nayak, J / PSI PRODUCTION IN PP COLLISIONS AT S**(1/2) = 200-GEV • AT RHIC. Phys.Rev.Lett.93:171801,2004. • • Jian-Wei Qiu, Ivan Vitev, RESUMMED QCD POWER CORRECTIONS TO NUCLEAR SHADOWING, • Phys.Rev.Lett.93:262301,2004 • Conferences / Workshops • Emil Mottola, organizer, “QCD and Gauge Theory • Dynamics in the RHIC Era”, April 2002, KITP • Rajan Gupta, organizer, “Modeling the QCD Equation of • State at RHIC”, February 2006, LLNL • Ivan Vitev, organizer, “LHC workshop at PANIC’05” • November 2005, Santa Fe • Terry Goldman, Mikkel Johnson, organizers, “PANIC’05” • November 2005, Santa Fe (Martin Cooper,Joe Carlson, P-25, T-16 ) LANL - LLNL

  21. II. Theory: Jet Quenching • Breakthrough theoretical work: • Formalism for calculating the energy • loss: GLV (Gyulassy-Levai-Vitev) • Implementation of energy loss, Cronin • scattering in PQCD hadron production M.Gyulassy,P.Levai,I.Vitev Phys.Rev.Lett. 85 (2000); Nucl.Phys.B571 (2000); Nucl.Phys.B594 (2001) I.Vitev, M.Gyulassy, Phys.Rev.Lett. 89 (2002); I.Vitev, Phys.Lett. B562 (2003); Phys.Lett. B630 (2005) Nuclear modification I.Vitev,M.Gyulassy,P.Levai,I.Vitev, in preparation

  22. PQCD Factorization and Energy Loss Theory Box of plasma Challenge: connection Pion cross section • Bjorken expanding medium: M.Gyulassy,I.Vitev,X.N.Wang, Phys.Rev.Lett. 86 (2001)

  23. Results on Energy and Centrality Dependence Establishing the E-loss mechanism Theory / Experiment Centrality Experimentally measured C.M. energy I.Vitev, M.Gyulassy, Phys.Rev.Lett. 89 (2002) I.Vitev, Phys.Lett.B 606 (2005) Pion suppression in A+A reactions Pion suppression in A+A reactions D. d’Enterria, Eur.Phys.J C (2005) I.Vitev,in preparation; hep-ph/0511273

  24. A+A E-loss in Back-to-Back Di-jets and Correlations • Multi-particle modification • Angular gluon distribution Tag Two particle suppression / enhancement in A+A reactions See talk by M. Brooks I.Vitev, Phys.Lett.B630 (2005)

  25. Theory: High Twist Shadowing Theory Shadowing is the ratio of DIS reduced cross sections – structure functions Coherent final state scattering theory Shadowing Data from: NMC Power suppressed ~ 1/QT J.W.Qiu, I. Vitev, Phys.Rev.Lett. 93 (2004) • QCD factorization approach, backgroundcolor magnetic field • Dynamical parton mass (QED analogy):

  26. A-, x- and Q2-Dependence: Numerical Results • The scale of higher twist per • nucleon is small: • The nuclear effect is of power law • nature: Q2 dependent Suppression in DIS Structure Functions Suppression in DIS Structure Functions J.W.Qiu, I. Vitev, Phys.Rev.Lett. 93 (2004)

  27. Shadowing in Neutrino+A and p+A Reactions • Dynamical shadowing for • sea quarks, valence quarks • and gluons • DIS-like t-channel FS scattering p+A No nuclear effect Structure Functions Nuclear suppression in p+A reactions STAR J.W.Qiu, I. Vitev, Phys.Lett.B 587 (2004) J.W.Qiu, I. Vitev, Phys.Lett.B 632 (2006)

  28. 2 Suppression + + Eff. E-loss Theory: Energy Loss in Cold Nuclear Matter • Evidence from low energy p+A reactions Nuclear suppression at forward rapidity Nuclear suppression in d+A reactions I.Vitev,T.Goldman,M.Johnson,J.W.Qiu, in preparation M.B.Johnson et al., Phys.Rev.C72 (2005) See talk by M. Brooks

  29. III. Heavy Quark Production and Modification + ... + ... Gluon fusion is not the dominant process in open charm production • Proposed back-2-back charm • triggered correlations I.V.,T.Goldman,M.Johnson,J.W.Qiu, Phys.Rev.D74 (2006)

  30. Nuclear Matter Effects on Charm Production LDRD: “Heavy Quarks as a Probe of a New State of Matter” Experimental y = 1.4-2.2 Very similar behavior of charm quarks (D-mesons) to light hadrons E-loss seems to play a similarly important role Nuclear suppression in d+A reactions Nuclear suppression in d+A reactions PHENIX data I.Vitev,T.Goldman,M.Johnson,J.W.Qiu, in preparation hep-ph/0511220 See talks by M. Brooks and P. McGaughey

  31. Future / LDRD Research Directions • Lattice QCD equation-of-state and heavy quarkonia From Nt=4 to Nt=6, 8 lattices Improved lattice actions Energy density Reduce large theoretical spread of "melting" temperatures of R. Gupta F.Karsch, Nucl.Phys.A698 (2002) • Transport coefficients of the QGP Thermal and electrical conductivity Non-equilibrium field theory Fractional quark energy loss E. Mottola • E-loss of heavy quarks at I. Vitev I.Vitev See talk by P. McGaughey

  32. Summary of Theory Effort / Directions • Heavy Ion Theory at Los Alamos • 4+1 staff, new external collaborations, extensive publication record. Participated / organized HIT conferences / workshops • Recent Theoretical Progress • Establishing the jet quenching theory: verified predictions versus C.M. energy, predictions versus centrality Cu+Cu, Au+Au • Understanding high twist shadowing: final state interactions. DIS structure functions F1, F2, neutrino-nucleus reactions F3, p+A reactions • Energy loss in cold nuclear matter: understanding the p+A rapidity asymmetry and verification at lower C.M. energies. • Future Theoretical Developments, LDRD • Heavy quark production / modification: charm on gluon scattering • Energy loss mechanism for heavy quarks: non-zero Y, novel e-loss • Transport coefficients:electrical and thermal conductivityof the plasma • Lattice QCD Equation-of-State and heavy quarkonia: improved simulations

  33. Analytic Models of Jet Quenching • Centrality dependence PQCD baseline: GLV E-loss: Quenched PQCD: Comparison • Predictions Verified with PHENIX and STAR I.Vitev,in preparation; hep-ph/0511273

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