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Big-Bang nucleosynthesis (BBN)

  1. Jul 12, 2008 #1

    jal

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    The present big bang theory is available at
    http://pdg.lbl.gov/2007/reviews/contents_sports.html
    Big-Bang nucleosynthesis (BBN) marks the boundary between the established and the speculative in big bang cosmology.
    It does not include the NEW experimental evidence that has been obtained from liquid hydrogen, solid hydrogen and quark gluon liquid, and free neutrons (life and decay).
    ========
    Here is a paper that tries to incorporate quark gluon liquid into the big bang.
    I am sure that this is the first paper of many more to come.
    http://arxiv.org/abs/0807.1610v1
    Relativistic Nucleus-Nucleus Collisions and the QCD Matter Phase Diagram
    Authors: Reinhard Stock (Physics Department, University of Frankfurt)
    (Submitted on 10 Jul 2008)
    This primordial matter, prior to hadronization, should be deconfined in its QCD sector, forming a plasma (i.e. color conducting) state of quarks and gluons: the Quark Gluon Plasma (QGP).
    ========

    Since this is a big paper, start with the Summary on page 129.
    -------------

    p.41
    For guidance concerning the overall time-order of the system evolution we consider
    information [87] obtained from Bose-Einstein correlation analysis of pion
    pair emission in momentum space (for detail see chapter 7). Note that pions
    should be emitted at any stage of the evolution, after formation time, from the
    surface regions of the evolving ”fire-tube”. Bulk emission of pions occurs, of
    course, after hadronization (the latest stages illustrated in the evolution sketch
    given in Fig. 2.17). The dynamical pion source expansion models by Heinz [88]
    and Sinyukov [89] elaborate a Gaussian emission time profile, with mean τf
    (the decoupling time) and width _τ (the duration of emission).
    p.43
    The above considerations suggest that a quark-gluon plasma state should be created early in the expansion dynamics at √s = 200 GeV , at about T = 300 MeV , that expands hydrodynamically until hadronization is reached, at T ≈ 165 − 170 MeV . Its manifestations will be considered in chapters 3 to 6.
    At the lower SPS energy, up to 17.3GeV , we can conclude, with some caution, that a deconfined hadronic matter system should exist at T ≈ 200 MeV , in the closer vicinity of the hadronization transition. It may closely resemble the QGP state of lattice QCD, near Tc.
    --------
    Note: In the big bang, there is not a surface region. The whole “cosmo” is in the quark gluon phase. Therefore, there are no pions being emitted from the surface or from the bulk of the interior of the quark gluon “ball”. If any such surface existed, it would have to be beyond our light cone horizon.
    --------
    p.64
    Hadronization in e+e− annihilation thus occurs from local clusters (or strings), isolated in vacuum, of different mass but similar energy density corresponding to QCD confinement.
    In the fit of Fig. 2.16 this volume sum amounts to about 45 fm^3 [84]; the individual cluster volumes are thus quite small, of magnitude a few fm^3 [85]
    .-------
    note: This is a new observation that needs consideration in an expanding model of the universe.
    -------
    p. 65
    However, to be precise: the hadronizing QCD system of extended matter decaying quantum coherently, could still be a non-equilibrium precursor of the ideal equilibrium QGP, because we have seen above that hadrochemical equilibrium also occurs in e+e− annihilation, where no partonic equilibrium exists. It gets established in the course of hadronization, irrespective of the degree of equilibrium prevailing in the preceding partonic phase.
    --------
    p.67
    We are thus witnessing at hadronization a Hubble expanding system of local fireballs. The detailed implications of this picture have not been analyzed yet. Note that a central RHIC collision thus does not correspond to a single hadronization ”point” in the [T, μ] plane of
    Fig. 1.1 but samples {T, μ} along the QCD parton-hadron coexistence line [132].
    -------
    ========
    note: The next paper that I’d like to find would be an explanation of the path taken for confinement.
    What are the probabilities that the quark gluon liquid went 100% to a confinement of neutrons?
    What are the probabilities that the quark gluon liquid went 100% to a confinement of protons?
    What are the probabilities that the quark gluon liquid went to a confinement of both, protons and neutrons?

    Novices might find my blog explanation interesting.
     
  2. jcsd
  3. Jul 13, 2008 #2

    jal

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    p.110
    The Brown-Rho model [134] predicted the ̺ mass to drop to zero at T = Tc, occuring as a certain power of the ratio hqqimed / hqqivac of the chiral condensate in medium and in vacuum which approaches zero at the chiral phase transition temperature, then expected to coincidence with the deconfinement temperature.This ”dropping mass” model is ruled out by the data in Fig. 6.5 and 6.6. This is, perhaps, a further manifestation of the fact that the deconfined QGP state at T ≥ Tc is not a simple pQCD gas of quarks and gluons [213]. In fact, lattice calculations [232, 257] find indications of surviving light qq pair correlations in the vector channel at T ≥ Tc. Thus the two most prominent symmetries of the QCD Lagrangian, non abelian gauge invariance (related to confinement) and chiral invariance (related to mass) might exhibit different critical patterns at T = Tc and low baryo-chemical potential. This conjecture is best illustrated by the observation that the broad, structureless NA60 excess dilepton spectrum of Fig. 6.6 (after cocktail ̺ subtraction) is equally well reproduced by a T ≈ 160 − 170 MeV calculation in hadronic (equilibrium) matter [133, 253, 254], and by a thermal QGP fireball of qq annihilation at this average temperature [252], as illustrated here by the model curve labeled ”Kaempfer” in Fig. 6.5 (right panel). This observation has invited the concept of parton-hadron duality near Tc [258], which might be provocatively translated as ”the QCD chiral transition properties can not be unambiguously disentangled from the deconfinement transition effects at Tc” [256].
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    reference (see arxiv.org for the debate)
    *** http://arxiv.org/abs/nucl-th/0509085v4
    Semi-central In-In collisions and Brown-Rho scaling
    Authors: V.V. Skokov, V.D. Toneev
    (Submitted on 28 Sep 2005 (v1), last revised 9 Mar 2006 (this version, v4))
    In connection with the claim made at the Quark Matter 2005 Conference that the Brown-Rho scaling is ruled out by NA60 data we consider dimuon production from semi-central In+In collisions in a full dynamical model. It is shown that if only a modification of the density-dependent $\rho$-mass is allowed, the maximum of dimuon invariant mass spectra is only slightly below experimental one. The additional inclusion of the temperature-dependent modification factor shifts the spectrum maximum toward lower invariant masses making calculation results incompatible with data. A further study is needed to disentangle the BR dropping $\rho$ mass scaling and strong broadening.
    --------
    *** http://arxiv.org/abs/0805.3342v1
    Baryons and Vector Dominance in Holographic Dual QCD
    Authors: Mannque Rho
    (Submitted on 21 May 2008)
    At the intuitively simplest level, one may attribute the mass mostly to
    the spontaneous breaking of chiral symmetry as prescribed by QCD.

    =======
    Soooo!! Do we have mass or not in the quark gluon liquid?
    Introducing mass into the quark gluon stage of the big bang also means introducing gravity. We have no evidence to support that gravity exist at this scale.
    This would result in all kinds of complications; reactions would be slower, distances of reactions would be affected, an event horizon would be created, and there would be density gradients, as you approach the center, within the quark gluon liquid.
    I’m sure that you can figure out the implications … if gravity starts only at confinement of the quark gluon liquid.
    Hummm!
    If the Brown-Rho model is correct, then CERN will not be able to produce a black hole with the quark gluon liquid.
     
  4. Jul 14, 2008 #3

    jal

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    If you are interested in finding out what is going on and in getting different opinions then check out …
    http://www2.yukawa.kyoto-u.ac.jp/~nfqcd08/symposium/index.html
    YITP International Symposium

    Fundamental Problems in Hot and/or Dense QCD

    at Yukawa Institute for Theoretical Physics (YITP)
    in Kyoto, Japan, March 3-6, 2008
    ======
    Keep in mind, … nobody KNOWS, … everyone is making predictions.
    ========
     
  5. Jul 15, 2008 #4

    jal

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    Learning material
    http://web.mit.edu/8.712/www/
    Relativistic Heavy-Ion Course
    Prof. Craig Ogilvie, MIT
    Video-conference Course, Fall 1998
    --------
    http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=05-38
    RHIC Scientists Serve Up "Perfect" Liquid
    New state of matter more remarkable than predicted -- raising many new questions
    April 18, 2005
    ==========
    http://tkynt2.phys.s.u-tokyo.ac.jp/~hirano/talks.html
    Tetsufumi Hirano
    ----------
    http://www.veccal.ernet.in/~pmd/qm2008/webpage/qm2008Program.htm

    20th International Conference on Nucleus Nucleus Collisions
    February 4-10, 2008: Jaipur India
    ========
     
  6. Jul 16, 2008 #5

    jal

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    Reinhard Stock made an interesting observation that will make some people in “Beyond the Standard Model” happy.
    I would interpret the mechanism/cause as “minimum length”.
    This, with the Brown-Rho model, that says that there is no mass in the quark gluon liquid, would move LQG into the observable scale and it could be developed into a “working tool”.
     
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