Presentation is loading. Please wait.

Presentation is loading. Please wait.

Rainer J. FriesRecombination & Fragmentation #1 Rainer J. Fries University of Minnesota Recombination and Fragmentation of Hadrons from a Dense Parton.

Published byGerald Lynch Modified over 8 years ago

Similar presentations

Presentation on theme: "Rainer J. FriesRecombination & Fragmentation #1 Rainer J. Fries University of Minnesota Recombination and Fragmentation of Hadrons from a Dense Parton."— Presentation transcript:

1 Rainer J. FriesRecombination & Fragmentation #1 Rainer J. Fries University of Minnesota Recombination and Fragmentation of Hadrons from a Dense Parton Phase  R.J. Fries, C. Nonaka, B. Müller & S.A. Bass, PRL 90, 202303 (2003)  R.J. Fries, C. Nonaka, B. Müller & S.A. Bass, nucl-th/0305079, JPG t.a.  R.J. Fries, C. Nonaka, B. Müller & S.A. Bass, PRC 68, 044902 (2003)  C. Nonaka, R.J. Fries & S.A. Bass, nucl-th/0308051, submitted to PLB Talk at the RIKEN Workshop on Flow and Collective Phenomena BNL, November 19, 2003

2 Rainer J. FriesRecombination & Fragmentation #2 Outline Motivation: hadron spectra, ratios and flow at RHIC The recombination idea Calculations using recombination + fragmentation v 2 scaling

3 Rainer J. FriesRecombination & Fragmentation #3 Jet quenching: suppression of hard particle production Central Au+Aucollisions: suppression of pions by a factor ~5 Suppression of hard (pQCD) hadron production

4 Rainer J. FriesRecombination & Fragmentation #4 Baryon enhancement at high p t  where does the large proton over pion ratio at high p t come from?  Why do mesons differ from hadrons? For p t >2 GeV, protons are as abundant as pions and kaons! hadron production via fragmentation yields p/π ratio of ~0.1

5 Rainer J. FriesRecombination & Fragmentation #5 Elliptic flow of K 0 and  hyperon v 2 saturates later and higher than kaon v 2. same effect observed for protons and pions. what drives the different p T scales for K S and Λ v 2 ?  novel mechanism of baryon formation? Sorensen SQM 2003

6 Rainer J. FriesRecombination & Fragmentation #6 A possible solution to the puzzle:  parton recombination Where is pQCD?

7 Rainer J. FriesRecombination & Fragmentation #7 Recombination vs Fragmentation for exponential parton spectrum, recombination is more effective than fragmentation baryons are shifted to higher p t than mesons, for same quark distribution  understand behavior of protons! recombining partons: p 1 +p 2 =p h fragmenting parton: p h = z p, z<1 Fragmentation:

8 Rainer J. FriesRecombination & Fragmentation #8 The recombination idea basic assumptions: at low p t, quarks and antiquarks recombine into hadrons on a hadronization hypersurface: hadron momentum P is much larger than masses and momentum scales of the wave function of the hadron;  features of the parton spectrum are shifted to higher p t in the hadron spectrum parton spectrum has thermal part (effective quarks) and a power law tail (quarks and gluons) from pQCD.

9 Rainer J. FriesRecombination & Fragmentation #9 The nine lives of recombination High Energy Physics Phenomenology: K.P. Das & R.C. Hwa, Phys. Lett. B68, 459 (1977) Quark-Antiquark Recombination in the Fragmentation Region  description of leading particle effect (field of recent activity!) Heavy-Ion Phenomenology: T. S. Biro, P. Levai & J. Zimanyi, Phys. Lett. B347, 6 (1995) ALCOR: a dynamical model for hadronization  yields and ratios via counting of constituent quarks R.C. Hwa & C.B. Yang, PRC66, 025205 (2002) R. Fries, B. Mueller, C. Nonaka & S.A. Bass, Phys. Rev. Lett. 90 V. Greco, C.M. Ko and P. Levai, Phys. Rev. Lett. 90 Anisotropic flow: S. Voloshin, QM2002, nucl-ex/020014 Z.W. Lin & C.M. Ko, Phys. Rev. Lett 89, 202302 (2002) D. Molnar & S. Voloshin, nucl-th/0302014

10 Rainer J. FriesRecombination & Fragmentation #10 Recombination formalism I Express number of mesons by the quark density matrix . Introduce 2-quark and meson Wigner functions W, .

11 Rainer J. FriesRecombination & Fragmentation #11 Recombination formalism II choose a hypersurface Σ for hadronization use local light cone coordinates (hadron defining the + axis) w a (r,p): single particle distribution functions for quarks at hadronization Ф M & Ф B : light-cone wave-functions for the meson & baryon respectively x, x’ & (1-x): momentum fractions carried by the quarks integrating out transverse degrees of freedom yields:

12 Rainer J. FriesRecombination & Fragmentation #12 Recombination of an exponential spectrum important features: p h = Σ p q d 3 N/dp 3 h  (w q ) n (with n=2,3) for an exponential distribution:  product of all distribution functions only depends on hadron momentum!  results are insensitive to the model used for recombination  Baryon/Meson ratio is independent of momentum, e.g. (C p, C π : degeneracy factors)

13 Rainer J. FriesRecombination & Fragmentation #13 Recombination vs. Fragmentation Fragmentation… … but it wins out at large p T, when the spectrum is a power law ~ (p T ) -b : … never competes with recombination for a thermal (exponential) spectrum:

14 Rainer J. FriesRecombination & Fragmentation #14 Recombination + Fragmentation Fragmentation of perturbative partons dominates at high p t. Recombination kicks in at 4-6 GeV at RHIC energies. Our description of recombination fails when  /P T and m/P T corrections become large (from 1-2 GeV on at RHIC). But: recombination will still be the dominant hadronization mechanism. Take into account binding energies, mass effects.

15 Rainer J. FriesRecombination & Fragmentation #15 Results & Comparison to Data hadron spectra hadron ratios R AA

16 Rainer J. FriesRecombination & Fragmentation #16 Input and Parameters I Input for the model is the momentum distributions of constituent quarks and anti-quarks at the time of hadronization the quark distribution is assumed to have a low p t thermal component and a high p t pQCD mini-jet component the thermal component is parameterized as: with a flavor dependent fugacity g a, temperature T, rapidity width Δ and transverse distribution f(ρ,ф). the pQCD component is parameterized as: with parameters C, B and β taken from a lo pQCD calculation

17 Rainer J. FriesRecombination & Fragmentation #17 Input and parameters II Use hypersurface  with t 2 -z 2 =  2 ;  = 5 fm/c. Fix T=175 MeV Determine: Radial flow  =0.55 c Emission volume Energy loss parameter Fugacities

18 Rainer J. FriesRecombination & Fragmentation #18 Hadron Spectra I

19 Rainer J. FriesRecombination & Fragmentation #19 Hadron Spectra II

20 Rainer J. FriesRecombination & Fragmentation #20 Hadron Ratios vs. p t

21 Rainer J. FriesRecombination & Fragmentation #21 anisotropic or “elliptic” flow is sensitive to initial geometry Elliptic Flow more flow in collision plane than perpendicular to it less absorption in collision plane than perpendicular to it low p t domain:high p t domain: total elliptic flow is the sum of both contributions: r(p t ): relative weight of the recombination contribution in spectra

22 Rainer J. FriesRecombination & Fragmentation #22 Elliptic Flow: partons at low p t azimuthal anisotropy of parton spectra is determined by elliptic flow: with Blastwave parametrization for parton spectra: (Ф p : azimuthal angle in p-space) azimuthal anisotropy is parameterized in coordinate space and is damped as a function of p t :

23 Rainer J. FriesRecombination & Fragmentation #23 Parton Number Scaling of Elliptic Flow in the recombination regime, meson and baryon v 2 can be obtained from the parton v 2 in the following way:  neglecting quadratic and cubic terms, one finds a simple scaling law:

24 Rainer J. FriesRecombination & Fragmentation #24 Results & Comparison to Data elliptic flow

25 Rainer J. FriesRecombination & Fragmentation #25 Elliptic Flow: Input parton elliptic flow:relative weight of recombination: grey area: region of uncertainty for limiting behavior of R & F hadron v 2 calcuated separately for R and F and superimposed via:

26 Rainer J. FriesRecombination & Fragmentation #26 Flavor Dependence of Recombination  Recombination describes measured flavor-dependence!

27 Rainer J. FriesRecombination & Fragmentation #27 Elliptic Flow: Recombination vs. Fragmentation high p t : v 2 for all hadrons merge, since v 2 from energy-loss is flavor blind  charged hadron v 2 for high pt shows universal & limiting fragmentation v 2  quark number scaling breaks down in the fragmentation domain

28 Rainer J. FriesRecombination & Fragmentation #28 Bill Zajc (DNP Tucson) New PHENIX Run-2 result on v2 of  0 ’s: New STAR Run-2 result on v2 for  ’s: ALL hadrons measured to date obey quark recombination systematics PHENIX Preliminary 00  STAR Preliminary  smoking gun for recombination  measurement of partonic v 2 !

29 Rainer J. FriesRecombination & Fragmentation #29 New developments I Another test: the  meson. Do we see a mass effect or the valence quark structure of hadrons? Reco differs from hydro! The deuteron and the pentaquark should have tremendous v 2. STAR: deuteron v 2 follows the scaling law!

30 Rainer J. FriesRecombination & Fragmentation #30 New developments II The  + will be measured at RHIC. Will v 2 scale with n=5? What about other resonances? Influence of the hadronic stage?

31 Rainer J. FriesRecombination & Fragmentation #31 Summary & Outlook The Recombination + Fragmentation Model: provides a natural solution to the baryon puzzle at RHIC describes the intermediate and high p t range of  hadron ratios & spectra  jet-quenching phenomena  elliptic flow provides a microscopic basis for the Statistical Model One universal parametrization of the parton phase can explain the data! v 2 : proof of collectivity in the parton phase issues to be addressed in the future: entropy & energy resonances and influence of the hadronic phase need improved data of identified hadrons at high p t

32 Rainer J. FriesRecombination & Fragmentation #32 The End

33 Rainer J. FriesRecombination & Fragmentation #33 Centrality Dependence of Spectra & Ratios R+F model applicable over full range of centrality deviations from SM as soon as fragmentation sets in low p t deviations due to neglected const. quark mass

34 Rainer J. FriesRecombination & Fragmentation #34 Flavor Dependence of high-p t Suppression R+F model describes different R AA behavior of protons and pions Lambda’s already exhibit drop into the fragmentation region in the fragmentation region all hadron flavors exhibit jet-quenching

35 Rainer J. FriesRecombination & Fragmentation #35 Elliptic Flow: partons at high p t azimuthal anisotropy is driven by parton energy/momentum loss Δp t L: average thickness of the medium the unquenched parton p t distribution is shifted by Δpt.  v 2 is then calculated via:

36 Rainer J. FriesRecombination & Fragmentation #36 pQCD approach to parton recombination AA meson double parton scattering scales: single parton scattering and fragmentation scales: T. Ochiai, Prog. Theor. Phys. 75 (1986) 1184

37 Rainer J. FriesRecombination & Fragmentation #37 New developments III Can we distinguish production scenarios for the pentaquark? 5q recombination K+N recombination & coalescence, K+N fragmentation & coalescence K+N fragmentation & coalescene in a jet cone (= 5q fragmentation) Even obtain information about the structure?

Download ppt "Rainer J. FriesRecombination & Fragmentation #1 Rainer J. Fries University of Minnesota Recombination and Fragmentation of Hadrons from a Dense Parton."

Similar presentations

PID v2 and v4 from Au+Au Collisions at √sNN = 200 GeV at RHIC

PID v2 and v4 from Au+Au Collisions at √sNN = 200 GeV at RHIC
Mass, Quark-number, Energy Dependence of v 2 and v 4 in Relativistic Nucleus- Nucleus Collisions Yan Lu University of Science and Technology of China Many.

Mass, Quark-number, Energy Dependence of v 2 and v 4 in Relativistic Nucleus- Nucleus Collisions Yan Lu University of Science and Technology of China Many.
1 Jet Structure of Baryons and Mesons in Nuclear Collisions l Why jets in nuclear collisions? l Initial state l What happens in the nuclear medium? l.

1 Jet Structure of Baryons and Mesons in Nuclear Collisions l Why jets in nuclear collisions? l Initial state l What happens in the nuclear medium? l.
Effects of minijet degradation on hadron observables in heavy-ion collisions Lilin Zhu Sichuan University QPT2013, Chengdu.

Effects of minijet degradation on hadron observables in heavy-ion collisions Lilin Zhu Sichuan University QPT2013, Chengdu.
Recombination for JET Shower MC: Status and Discussion Rainer Fries Texas A&M University JET NLO & MC Meeting Wayne State University, August 23, 2013 On.

Recombination for JET Shower MC: Status and Discussion Rainer Fries Texas A&M University JET NLO & MC Meeting Wayne State University, August 23, 2013 On.
K*(892) Resonance Production in Au+Au and Cu+Cu Collisions at  s NN = 200 GeV & 62.4 GeV Motivation Analysis and Results Summary 1 Sadhana Dash Institute.

K*(892) Resonance Production in Au+Au and Cu+Cu Collisions at  s NN = 200 GeV & 62.4 GeV Motivation Analysis and Results Summary 1 Sadhana Dash Institute.
Identified particle transverse momentum distributions in 200 GeV Au+Au collisions at RHIC 刘海东 中国科技大学.

Identified particle transverse momentum distributions in 200 GeV Au+Au collisions at RHIC 刘海东 中国科技大学.
Heavy Quark Probes of QCD Matter at RHIC Huan Zhong Huang University of California at Los Angeles ICHEP-2004 Beijing, 2004.

Heavy Quark Probes of QCD Matter at RHIC Huan Zhong Huang University of California at Los Angeles ICHEP-2004 Beijing, 2004.
Hadronization of Dense Partonic Matter Rainer Fries University of Minnesota Talk at SQM 2006 March 28, 2006.

Hadronization of Dense Partonic Matter Rainer Fries University of Minnesota Talk at SQM 2006 March 28, 2006.
DNP03, Tucson, Oct 29, 2003 1 Kai Schweda Lawrence Berkeley National Laboratory for the STAR collaboration Hadron Yields, Hadrochemistry, and Hadronization.

DNP03, Tucson, Oct 29, Kai Schweda Lawrence Berkeley National Laboratory for the STAR collaboration Hadron Yields, Hadrochemistry, and Hadronization.
03/14/2006WWND2006 at La Jolla1 Identified baryon and meson spectra at intermediate and high p T in 200 GeV Au+Au Collisions Outline: Motivation Intermediate.

03/14/2006WWND2006 at La Jolla1 Identified baryon and meson spectra at intermediate and high p T in 200 GeV Au+Au Collisions Outline: Motivation Intermediate.
We distinguish two hadronization mechanisms:  Fragmentation Fragmentation builds on the idea of a single quark in the vacuum, it doesn’t consider many.

We distinguish two hadronization mechanisms:  Fragmentation Fragmentation builds on the idea of a single quark in the vacuum, it doesn’t consider many.
Resolution of Several Puzzles at Intermediate p T and Recent Developments in Correlation Rudolph C. Hwa University of Oregon Quark Matter 05 Budapest,

Resolution of Several Puzzles at Intermediate p T and Recent Developments in Correlation Rudolph C. Hwa University of Oregon Quark Matter 05 Budapest,
Nu XuInternational Conference on Strangeness in Quark Matter, UCLA, March 26 - 31, 20061/20 Search for Partonic EoS in High-Energy Nuclear Collisions Nu.

Nu XuInternational Conference on Strangeness in Quark Matter, UCLA, March , 20061/20 Search for Partonic EoS in High-Energy Nuclear Collisions Nu.
Jana Bielcikova (Yale University) for the STAR Collaboration 23 rd Winter Workshop on Nuclear Dynamics February 12-18, 2007 Two-particle correlations with.

Jana Bielcikova (Yale University) for the STAR Collaboration 23 rd Winter Workshop on Nuclear Dynamics February 12-18, 2007 Two-particle correlations with.
1 Searching for the QGP at RHIC Che-Ming Ko Texas A&M University  Signatures of QGP  Quark coalescence Baryon/meson ratio Hadron elliptic flows and quark.

1 Searching for the QGP at RHIC Che-Ming Ko Texas A&M University  Signatures of QGP  Quark coalescence Baryon/meson ratio Hadron elliptic flows and quark.
XXXIII International Symposium on Multiparticle Dynamics, September 7, 2003 Kraków, Poland Manuel Calderón de la Barca Sánchez STAR Collaboration Review.

XXXIII International Symposium on Multiparticle Dynamics, September 7, 2003 Kraków, Poland Manuel Calderón de la Barca Sánchez STAR Collaboration Review.
Identified and Inclusive Charged Hadron Spectra from PHENIX Carla M Vale Iowa State University for the PHENIX Collaboration WWND, March 14 2006.

Identified and Inclusive Charged Hadron Spectra from PHENIX Carla M Vale Iowa State University for the PHENIX Collaboration WWND, March
12-17 February 2007 Winter Workshop on Nuclear Dynamics STAR identified particle measurements at large transverse momenta in Cu+Cu collisions at RHIC Richard.

12-17 February 2007 Winter Workshop on Nuclear Dynamics STAR identified particle measurements at large transverse momenta in Cu+Cu collisions at RHIC Richard.
High p T identified hadron anisotropic flow and Deuteron production in 200 GeV Au+Au Collisions Shengli Huang Vanderbilt University for the PHENIX Collaboration.

High p T identified hadron anisotropic flow and Deuteron production in 200 GeV Au+Au Collisions Shengli Huang Vanderbilt University for the PHENIX Collaboration.

Similar presentations

Ads by Google