REVIEW
Behavior of Charmonium Systems after Deconfinement
High Energy Physics - Lattice · Submitted 23 Dec 2003 · 40 references
Pith's verdict: The S-wave survival result is solid and independently cross-checked; the P-wave dissolution claim is the softer half, and the paper mostly knows it.
T0 · AI review
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Referee report
The paper
The paper claims
Lattice spectral functions show the J/ψ and ηc surviving to about 1.5 Tc while the P-wave χ states are already gone near 1.1 Tc, so J/ψ suppression is a gradual melt rather than a sharp deconfinement thermometer.
The reading
What carries the argument
Two devices carry the argument. The first is the Maximum Entropy Method inversion of $G(τ) = ∫ dω σ(ω) K(ω,τ)$ with $K(ω,τ) = cosh(ω(τ-1/2T))/sinh(ω/2T)$, solved with Bryan's singular-value-decomposition algorithm and a Shannon entropy prior. The second, and the one that makes short temporal extents usable, is the choice of default model: because the high-frequency part of the spectral function is dominated by lattice artifacts and is assumed temperature-independent, the authors transplant the large-ω structure measured at 0.75 Tc or 0.9 Tc into the prior for every high-temperature fit, matching it smoothly to $m_1 ω^2$ at low ω. Alongside this sits a prior-free cross-check: the ratio $G(τ,T)/G_{recon}(τ,T)$, where $G_{recon}$ is built from a lower-temperature spectral function through the same kernel, so that any deviation from one is a genuine change in $σ$ rather than the known temperature dependence of the kernel.
Extended reading notes
Core claim
The central claim is that the 1S charmonia are far more robust in a hot gluon plasma than potential-model arguments suggested, while the 1P states are far more fragile. Above Tc the authors compare each measured temporal correlator with a 'reconstructed' correlator built by feeding the spectral function measured at 0.75 Tc or 0.9 Tc through the finite-temperature kernel; for the pseudoscalar channel the ratio stays at one up to 1.5 Tc and only departs visibly at 2.25 Tc and 3 Tc, while for the scalar and axial channels the measured correlator is already 60–120% larger than the reconstructed one at 1.1–1.5 Tc, the signature of spectral weight having moved down to around twice the quark mass. Reconstructed spectral functions bear this out: a strong peak at the zero-temperature mass persists for ηc and J/ψ through 1.5 Tc, weakens at 2.25 Tc, and is no longer statistically significant at 3 Tc, whereas the χc peaks are absent from the spectral function at 1.12 Tc. A secondary result is that the screening masses rise steadily above Tc even where the pole mass does not move, which the authors trace to a medium-modified dispersion relation with a speed coefficient below one, corroborated by the smaller-than-relativistic shift of the peak with spatial momentum at 1.5 Tc.
Load-bearing premise
The whole high-temperature reconstruction rests on the premise that the large-frequency part of the spectral function is a temperature-independent lattice artifact, so the same high-energy shape can be reused as the prior at every temperature; if that shape drifts with temperature, the low-frequency peak that carries the survival claim is pulled by the prior.
Editorial extensions
If this is right
- The sequential-melting picture changes quantitatively: χc0 and χc1 dissolution near Tc removes the roughly 40% indirect contribution to the observed J/ψ yield first, and the directly produced J/ψ then survives with little further loss until about 1.5 Tc.
- Dilepton spectra from a thermalized plasma should show a J/ψ peak that weakens gradually between roughly 1.5 Tc and 3 Tc rather than switching off at a single temperature, with about a 25% further reduction in integrated strength at 2.25 Tc for a near-charm quark mass.
- Because screening masses rise while pole masses stay put, a lattice calculation that quotes only screening masses above Tc will overstate the in-medium mass shift; the two quantities must be separated through a modified dispersion relation.
- The melting temperature depends on quark mass: for lighter quarks the pseudoscalar correlator departs from the reconstructed one already at 1.24 Tc, while the heaviest quark studied shows no modification through 1.5 Tc.
Reading between the lines
- If the S-wave survival is real, the sharpness of J/ψ suppression as a thermometer is set by the χ states, not the J/ψ, which suggests that the experimentally cleaner signal near Tc is the step in the dilepton yield from P-wave feed-down rather than the endpoint of the J/ψ peak itself.
- The claim that the high-frequency spectral structure is temperature-independent is testable independently of charmonium: a finer lattice at fixed temperature with more temporal points should reproduce the same large-ω bump structure, and any drift in it would propagate straight into the low-ω peak positions reported here.
- The modified dispersion relation inferred from the screening-versus-pole mismatch is a prediction for lattice spectroscopy at nonzero momentum in any heavy-quark channel, not just charmonium, and could be checked against the momentum dependence of the restored correlator ratio.
- An unquenched version of this study would be the decisive comparison: dynamical light quarks add pion-induced broadening below Tc and could push the χ dissolution temperature below the transition, which would sharpen rather than weaken the two-stage melting picture.
Original abstract
We present a study of charmonia in hot gluonic plasma, for temperatures upto three times the deconfinement transition temperature Tc. q \bar{q} systems with quark masses close to the charm mass and different spin-parity quantum numbers were studied on very fine isotropic lattices. The analysis of temporal correlators, and spectral functions constructed from them, shows that the J/psi and eta_c survive up to quite high temperatures, with little observable change up to 1.5 Tc, and then gradually weakening and disappearing by 3 Tc. For the scalar and axial vector channels, serious modifications are induced by the hot medium already close to Tc, possibly dissociating the mesons by 1.1 Tc.
The compiled record
The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
The abstract, sentence by sentence
We present a study of charmonia in hot gluonic plasma, for temperatures upto three times the deconfinement transition temperature Tc. q \bar{q} systems with quark masses close to the charm mass and different spin-parity quantum numbers were studied on very fine isotropic lattices. The analysis of temporal correlators, and spectral functions constructed from them, shows that the J/psi and eta_c survive up to quite high temperatures, with little observable change up to 1.5 Tc, and then gradually weakening and disappearing by 3 Tc. For the scalar and axial vector channels, serious modifications are induced by the hot medium already close to Tc, possibly dissociating the mesons by 1.1 Tc.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We present a study of charmonia in hot gluonic plasma, for temperatures upto three times the deconfinement transition temperature Tc. q \bar{q} systems with quark masses close to the charm mass and different spin-parity quantum numbers were studied on very fine isotropic lattices. | contribution 0.75 | 0.95 | 0.04 | asserted 0.79 |
| s1 | The analysis of temporal correlators, and spectral functions constructed from them, shows that the J/psi and eta_c survive up to quite high temperatures, with little observable change up to 1.5 Tc, and then gradually weakening and disappearing by 3 Tc. | result 1.00 | 0.95 | 0.52 | asserted 1.00 |
| s2 | For the scalar and axial vector channels, serious modifications are induced by the hot medium already close to Tc, possibly dissociating the mesons by 1.1 Tc. | result 0.98 | 0.89 | 0.16 | hedged possibility 0.89 |
What was examined, and what was not
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Figures
Showing 18 of the paper's 20 figures. See all figures in the PDF ↗ Figures reproduced from arXiv:hep-lat/0312037 by the authors.
References
How later papers used it
60 later papers cite it
1 paper by the same authors is listed below: 1 used its method or tool.
Uses its method or tool 1 of 7 papers with this label · 1 by the same authors
By the same authors
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Followed the procedure proposed in this paper to eliminate the trivial temperature dependence of the integration kernel and calculate reconstructed correlators.
On temperature dependence of quarkonium correlators (2008) (same authors) · 1.00 · paraphrased: the licence does not allow quoting
How the literature uses it
54 arXiv papers cite this in 101 sentences
Papers whose main result relates to this one's
States a conflicting result 2 papers
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Our analysis suggests that $\Jpsi$ is melted already at $1.46~T_c$ and $\eta_c$ starts to dissolve at $1.46~T_c$ and does not exist at higher temperatures.
Charmonium correlation and spectral functions at finite temperature · 0.97
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As a result, it is found that while J/psi and eta_c manifest themselves as significant peaks in the spectral function below the deconfinement temperature T_c, they quickly dissolve into the continuum and almost completely disappear at temperatures between 1.0 T_c and 1.1 T_c.
Charmonium spectra at finite temperature from QCD sum rules with the maximum entropy method · 0.86
Papers citing it · 54 sentences without a confident label
Contests it 1 paper
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This seems to contradict the conclusions made in Refs. [ref] , where the analysis of the spectral function using the MEM indicated that the first peak survives.
Can quarkonia survive deconfinement ? · Numerical results with the potential $V(r,T)$ · contest 0.86
Uses its method or tool 7 papers
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Let us start from the Euclidean correlator [ref] [equation] and take the integral ($β= 1/T$) [equation] Together with the definition of the reconstructed correlator [ref] [equation] i.e. taking the spectral density at zero temperature, one finds equivalently to ([ref]) but in terms of the Euclidean correlators [ref] , [equation]
R-charge thermodynamical spectral sum rule in N=4 Yang-Mills theory · Euclidean correlator · 0.83
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Therefore to eliminate the trivial temperature dependence of the integration kernel we follow the procedure proposed in Ref. [ref] and calculate the so-called reconstructed correlators [equation] where $T^*$ is some reference temperature well below $T_c$.
On temperature dependence of quarkonium correlators · Lattice calculations of quarkonium correlators · 1.00
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This can be investigated using so-called reconstructed correlators [ref] .
Electrical conductivity of the quark-gluon plasma: perspective from lattice QCD · Reconstructed correlators · 0.97
Uses its data or values 3 papers
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Therefore, for comparison with our model predictions, we use the data obtained on isotropic lattices [ref] .
Can quarkonia survive deconfinement ? · Direct comparison of the correlation functions with lattice data · 0.93
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In particular at $3T_c$ this ratio deviates from one by about $10%$ [ref] .
On temperature dependence of quarkonium correlators · The temperature dependence of the pseudo-scalar correlators · 0.92
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We use gauge field ensembles which have been generated and used previously by the Bielefeld group to study screening masses and spectral functions [ref] .
Quark propagator at finite temperature and finite momentum in quenched lattice QCD · Simulation setup · 0.83
Compares with it 7 papers
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The results are consistent with previous lattice studies of charmonium spectral functions [ref] , in which the spectral functions for the Ps and V channels in the deconfinement phase (but at not so high temperature) show a peak structure around the $η_c$ and $J/ψ$ masses like the result at zero temperature.
Study of constant mode in charmonium correlators at finite temperature · Finite temperature results · 0.87
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We compare the calculated correlators to recent numerical results calculated from isotropic [ref] and anisotropic [ref] lattice formulations.
Can quarkonia survive deconfinement ? · Quarkonium correlators at zero temperature · 1.00
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This coincides with the thermal properties of heavy quarkonia observed by model calculation and lattice numerical studies [ref] , but different from the observation of a previous lattice study on glueballs where the observed pole-mass reduction start even at $T≃0.8 T_c$ [ref] .
A Quenched Study of SU(3) Glueballs at Finite Temperature · Results of the single-cosh fit · 0.93
Cites it as background 18 papers
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The temperature dependence of the charmonium and bottomonium correlators in pseudo-scalar channel has been studied in Refs. [ref] .
On temperature dependence of quarkonium correlators · The temperature dependence of the pseudo-scalar correlators · 0.96
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The study of the properties of charmonia at finite temperature is one of the longstanding subjects on the lattice [ref] .
In-medium dispersion relations of charmonia studied by maximum entropy method · introduction · 0.96
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Extensive efforts have been devoted to studying charmonium [ref] and bottomonium [ref] in lattice QCD.
Charmonium properties at high temperatures from lattice QCD · Introduction · 0.96
Discussion
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