The high temperature transition and the (quasi)conformal behaviour Albert Deuzeman, MPL, Kohtaroh Miura, Elisabetta Pallante

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1 (yet) another extreme direction: QCD with many flavors Maria Paola Lombardo The high temperature transition and the (quasi)conformal behaviour Albert Deuzeman, MPL, Kohtaroh Miura, Elisabetta Pallante

2 (Quasi)Conformality and QCD with Many Flavors Hadronic Ph Phase Quasi Conformal/ Walking dynamics Conformal Window of QCD NAF NAF Nfc Nf

3 (Quasi)Conformality and High T QCD h/s < (3 5) / 4 p M. Panero 2010 S. Borsaniy et al.2011

4 Quasi Conformal QGP Strongly Coupled QGP Hadronic Phase

5 QCD in the T, Nf plane Kohtaroh Miura Lat2011

6 Outline The Conformal Window of QCD Results: High T transition and the quasi-conformal region Inside the Conformal Window Outlook

7 The discovery of the conformal window of QCD Miransky-Yamawaki, 1997; Appelquist et al For Nf > 8 the perturbative b function of QCD develops a second 0 : the Banks-Zacs IRFP. Then the coupling runs to IRFP CONFORMAL WINDOW Chiral Symmetry Breaking requires a>acr: 1) IRFP < acr CONFORMAL WINDOW a* acr 2) IRFP > acr IRFP disappears QCD-like, but: NEAR-CONFORMALITY, WALKING Conformal Relevant NEAR-CONFORMALITY, for transition Technicolor WALKING acr

8 Two Regimes for QCD acr Running : L sets the scale Walking : Separation of Scales: Interesting for Phenomenology

9 Running established up to 5 Flavors

10 Can we establish walking as well?

11 Can we establish walking as well? (if yes, it has to be for Nf > 5)

12 Most talks at Lat11 focussed on measuring the threshold Current Status of Walking Studies Chiral Condensate Enhancement Chiral Condensate Enhancement Appelquist et al 2010 Separation Of scales for Tc This talk; Kohtaroh Miura talk at Lattice 2011

13 Strategy Measure Tc/L (Nf) from asymptotic scaling difefrenf 0,4, Near-Conformal behaviour can be seen in: Different scales Llat and LIR Critical behaviour a la Braun-Gies J. Braun, H. Gies

14 Thermal transition and near-conformal dynamics J. Braun, H. Gies J. Braun Talk at xqcd2010

15 Tc/L constant for small Nf S. Gupta 2001

16 Chiral crossover, Nf=6

17 Polyakov loop, Nf = 6

18 bc for Nt=12 Nf = 6

19 Nf = 8 Deuzemann, MpL, Pallante 2008

20 Summary of results for bc

21 Estimating Tc/LLat for Nf = 6

22 Tc/L as a function of Nf Tc/L Scale separation Conventional running Nf

23 Two different scales: reconcile the results with expectation than Tc vanishes in the conformal window

24 Two different scales (ctnd) LLat = LIR

25 Trading LLAT for LIR : Toy calculation

26 Summary so far: New regime for Nf > 6: Results show that the simple linear dependence of Tc and L on Nf is lost for Nf > 6 The increase of Tc/L can be intepreted as due to the influence of an (approximate) IRFP...next : IRFP and conformal region

27 PHASES OF QCD ON THE LATTICE Miransky, Yamawaki 1998 evidence of) And in progress

28 The Bulk Transition of Nf = 12 16^3X 8 16^4

29 Critical scaling of the chiral transition Critical scaling of IRFP Two Tasks: 1) Chiral Symmetry vs Chiral Symmetry Breaking 2) If we measure an anomalous dimension, is this associated to Chiral or Conformal Symmetries?

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32 The transition of 4dQED on a Lattice Kocic, Kogut, MPL, 1992

33 E. Pallante at Lat2011

34 In a symmetric phase

35 Inside the conformal window THE IRFP

36 Appelquist, Fleming, Neil 2008

37 A. Hasenfratz 2011

38 Summary Our results and overall status: Nf = 6 seems to be the onset of near-conformal dynamics Agrees with Appelquist et al. Nf = 8 near-conformal, sensitive to IRFP Looking forward to more results from other groups (maybe some at Lattice2011?) Nf = 12 gives indirect evidence of IRFP : chirally symmetric Consensus that Nfc must be close to Nf12 (ONE )Open question Understanding the phase diagram in the Nf, T plane! Can these studies shed ight on the applicability of AdS/CFT methods to the analysis of QGP?

39 Conformality and near-conformality at zero and finite T: coupling walks in the plasma! Kaczmarez-Zantov 2005 J. Braun, H. Gies, 06 Conformal Window