Screened perturbation theory

Karsch, Frithjof; Patkós, A.; Petreczky, Péter

doi:10.1016/s0370-2693(97)00392-4

Cited by 217 publications

(249 citation statements)

References 19 publications

Supporting

Mentioning

246

Contrasting

Order By: Relevance

“…A possible strategy is the so-called "screened perturbation theory" [235] where the HTL-resummed Lagrangian Γ ef f in eq. (5.43) is now used at all momenta, soft and hard.…”

Section: Other Resummations and Lattice Calculationsmentioning

confidence: 99%

The quark–gluon plasma: collective dynamics and hard thermal loops

Blaizot¹,

Iancu²

2002

Physics Reports

515

714

View full text Add to dashboard Cite

We present a unified description of the high temperature phase of QCD, the so-called quark-gluon plasma, in a regime where the effective gauge coupling g is sufficiently small to allow for weak coupling calculations. The main focuss is the construction of the effective theory for the collective excitations which develop at a typical scale gT , which is well separated from the typical energy of single particle excitations which is the temperature T . We show that the short wavelength thermal fluctuations, i.e., the plasma particles, provide a source for long wavelength oscillations of average fields which carry the quantum numbers of the plasma constituents, the quarks and the gluons. To leading order in g, the plasma particles obey simple gauge-covariant kinetic equations, whose derivation from the general Dyson-Schwinger equations is outlined. By solving these equations, we effectively integrate out the hard degrees of freedom, and are left with an effective theory for the soft collective excitations. As a by-product, the "hard thermal loops" emerge naturally in a physically transparent framework. We show that the collective excitations can be described in terms of classical fields, and develop for these a Hamiltonian formalism. This can be used to estimate the effect of the soft thermal fluctuations on the correlation functions. The effect of collisions among the hard particles is also studied. In particular we discuss how the collisions affect the lifetimes of quasiparticle excitations in a regime where the mean free path is comparable with the range of the relevant interactions. Collisions play also a decisive role in the construction a Member of CNRS. E-mail: blaizot@spht.saclay.cea.fr b Member of CNRS. E-mail: iancu@spht.saclay.cea.fr c Laboratoire de la Direction des Sciences de la Matière du Commissariatà l'Energie Atomique of the effective theory for ultrasoft excitations, with momenta ∼ g 2 T , a topic which is briefly addressed at the end of this paper.

show abstract

“…A possible strategy is the so-called "screened perturbation theory" [235] where the HTL-resummed Lagrangian Γ ef f in eq. (5.43) is now used at all momenta, soft and hard.…”

Section: Other Resummations and Lattice Calculationsmentioning

confidence: 99%

The quark–gluon plasma: collective dynamics and hard thermal loops

Blaizot¹,

Iancu²

2002

Physics Reports

515

714

View full text Add to dashboard Cite

show abstract

“…This seems to have no explanation within perturbation theory, since the perturbative series for P fluctuates wildly as more terms are added; a Borel [28] or Padé [29] summation of the series does not help. Screened perturbation theory [30] applied to the hard thermal loop resummation does not produce agreement with the lattice results [31]. On the other hand, there have been reasonably successful attempts to fit the pressure by a gas of quasiparticles whose masses are the fit parameters [32].…”

Section: Flow and The Equation Of Statementioning

confidence: 95%

The quark gluon plasma: Lattice computations put to experimental test

Gupta

2003

Pramana - J Phys

View full text Add to dashboard Cite

show abstract

“…To understand this, we recall the following facts. It is with the resummation of the ring diagrams that the zero modes acquire a (screening) mass m s ∼ gT (m s can be defined as the solution of the gap equation [10,12]). And vice-versa: It is the screening phenomenon which explains the striking fact that, while all individual ring diagrams are infrared divergent, their total sum is convergent.…”

Section: Separation Of Long and Short Distance Regimesmentioning

confidence: 99%

“…From this one concludes that, due to the observable nature of the screening phenomenon, the long-range part F L , which encompasses the resummation-generated effects, is of physical nature and should therefore be RScl-independent. This can best be seen by determining the screening mass via the gap equation [10,12] which is equivalent to summing up the ring diagrams.…”

Section: Separation Of Long and Short Distance Regimesmentioning

confidence: 99%

Resummations of free energy at high temperature

Cvetič

Kögerler

2002

Phys. Rev. D

View full text Add to dashboard Cite

We discuss resummation strategies for free energy in quantum field theories at nonzero temperatures T . We point out that resummations should be performed for the short-and long-distance parts separately in order to avoid spurious interference effects and double-counting. We then discuss and perform Padé resummations of these two parts for QCD at high T . The resummed results are almost invariant under variation of the renormalization and factorization scales. We perform the analysis also in the case of the massless scalar φ 4 theory.

show abstract

Screened perturbation theory

Cited by 217 publications

References 19 publications

The quark–gluon plasma: collective dynamics and hard thermal loops

The quark–gluon plasma: collective dynamics and hard thermal loops

The quark gluon plasma: Lattice computations put to experimental test

Resummations of free energy at high temperature

Contact Info

Product

Resources

About