{"id":"d962e162-5757-4b47-9772-0397b6ed2951","arxiv_id":"1908.02792","paper_version":2,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":6.0,"correctness_risk":"low","formal_verification":"none","parameter_count":7,"one_line_summary":"From LHC data on particle spectra and femtoscopic radii, the entropy per unit rapidity is determined for pp and Pb-Pb collisions, and simulations trace about 95% of that entropy to the first fm/c.","lead":"The authors compute the entropy produced in proton-proton and lead-lead collisions at the LHC from measured particle spectra and source sizes, and simulate the early collision stages to estimate how hot the quark-gluon plasma gets and when most entropy appears. The result gives a data-anchored reference for the initial temperature and tests whether small collision systems reach chemical equilibrium.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The order-8 polynomial used for the pion (1+f)ln(1+f) term in pp collisions (Eq. 8) is unvalidated: coefficients and fit range are omitted, and pion F>1 invalidates the Taylor series it replaces. Pions dominate pp entropy, so this could shift the headline dS/dy values beyond quoted uncertainties.","rationale":"After reading the paper in good faith, the central entropy extraction is a careful data-driven application of the Pal-Pratt method with propagated systematics. The strongest risk to the headline numbers is not the HBT source-geometry relation, which is partially cross-checked in Appendix A, but the unvalidated replacement of the Bose-Einstein integrand by an order-8 polynomial for pions in pp collisions. The paper itself states that F exceeds unity for pions in pp, so the Taylor expansion in Eq. (2) is invalid; Eq. (8) introduces an undocumented polynomial. Because there are no coefficients or fit range, the pp result is not reproducible from the paper alone, and the error is not included in the uncertainty budget. The source-geometry uncertainty is already quantified at about 10% in pp; the polynomial could be an unquantified effect of similar or larger magnitude. The proposed numerical check is straightforward and would settle the issue. This does not change the reader's CONDITIONAL verdict; it sharpens one of the conditions. I agree with the reader's overall assessment of low arithmetical error risk and the tension with statistical models as a genuine falsifiable result.","tokens_in":19451,"tokens_out":10645,"duration_ms":107030,"concrete_test":"Recompute the pion contribution to dS/dy in minimum-bias and high-multiplicity pp collisions at sqrt(s)=7 TeV by numerical integration of the exact entropy integrand, using the measured pion spectra from Refs. [13] and [15] and the same R_inv(m_T) parametrizations as in Section III B, bypassing the order-8 polynomial of Eq. (8). If the difference from the published pion entropy exceeds the propagated statistical and systematic uncertainty (about 10%), the pp dS/dy values require revision. Separately, request the coefficients a_i and the range of F over which the polynomial was fitted; verify that the polynomial reproduces the exact integrand to better than a stated tolerance over the full F range encountered in the data.","verdict_should_be":"UNCHANGED","load_bearing_attack":"In Section II, Eq. (8), the authors replace the Bose-Einstein entropy integrand (1+f)ln(1+f) for pions in pp collisions with an order-8 polynomial in F, because the maximum pion phase-space density F(p_T) exceeds unity at low p_T and the Taylor expansion in Eq. (2) has unit radius of convergence. No coefficients a_i, no fit interval, and no maximum F are given, and no validation is shown. This matters because pions contribute roughly half of the pp entropy (20.1 of 37.8 in minimum bias, 71.4 of 135.7 in high multiplicity, Tables II and III), so a polynomial error at F>1 translates directly into the headline values dS/dy = 37.8±3.7 and 135.7±17.9 and into the S/Nch comparison with hadron-resonance-gas models. The source-geometry assumption, Eq. (5), is at least cross-checked in Appendix A, which changes pp entropy by about 10% (1σ); the polynomial approximation has no analogous cross-check. The exact function h(f) = -f ln f + (1+f)ln(1+f) is well-defined for all f>0 and can be integrated numerically, so the approximation is avoidable. The paper's own statement that the polynomial is 'valid for values of F obtained for pions in high-multiplicity pp collisions' is an assertion without the supporting data, coefficients, or error estimate.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The manuscript applies the Pal–Pratt method to ALICE data to compute the phase-space density and entropy per unit rapidity dS/dy from measured identified-particle spectra and HBT radii for sqrt(s)=7 TeV pp and sqrt(s_NN)=2.76 TeV Pb–Pb collisions. The central results are dS/dy = 11335 ± 1188 (0–10% Pb–Pb), 135.7 ± 17.9 (high-multiplicity pp), and 37.8 ± 3.7 (minimum-bias pp), corresponding to S/Nch values of 6.7 ± 0.8, 5.4 ± 0.7, and 5.2 ± 0.5. These values are compared with hadron-resonance-gas predictions at T_ch ≈ 156 MeV. The second part of the paper uses the KøMPøST pre-equilibrium propagator and the FluiduM viscous hydrodynamics code, with initial entropy profiles normalized to the measured final entropy, to reconstruct the average temperature profile at τ0 ≈ 1 fm/c and to conclude that in Pb–Pb collisions about 95% of the final entropy is already present by that time, with most entropy produced in the pre-equilibrium phase.","tokens_in":19741,"tokens_out":8434,"duration_ms":96215,"significance":"If the extraction is correct, this is the first LHC-era Pal–Pratt determination of final-state entropy and provides useful data-driven constraints on initial conditions and on entropy-per-charged-particle in pp and Pb–Pb collisions. The analysis has several genuine strengths: the pT-to-0 extrapolations use multiple functional forms with the spread carried into the systematic uncertainty; the HBT radii are parametrized with two different functions; feed-down from η, η′, and Σ0 is simulated with Pythia and corrected; and the pT-integrated pion, kaon, and proton yields are checked against published ALICE results. The dependence on the 1D-to-3D HBT radius relation is also cross-checked in Appendix A. These strengths make the central extraction credible, provided the unvalidated polynomial approximation for the pion phase-space density in pp collisions, discussed in the major comments, is addressed.","major_comments":[{"comment":"The order-8 polynomial replacement for the pion Bose-Einstein integrand in pp collisions is undocumented and unvalidated. The coefficients a_i, the fit range in F, and the maximum pion phase-space density F reached in the data are not given, and no comparison with the exact integrand h(f) = -f ln f + (1+f) ln(1+f) is shown. This is load-bearing because pions contribute 20.1 of 37.8 (minimum bias) and 71.4 of 135.7 (high multiplicity) to dS/dy in Tables II and III, so an error in this approximation propagates directly into the headline values and into the S/Nch comparison. Please provide the coefficients and an explicit validation (for example, the maximum relative error over the actual F range), or replace the polynomial with numerical integration of the exact integrand, which is straightforward in this one-dimensional integral.","section":"Section II, Eq. (8)"},{"comment":"The contributions of unmeasured species (η, η′, n, Σ, and the neutral-kaon component) are estimated by assuming that the entropy per particle is similar to that of the nearest measured species, with yields determined from a Pythia simulation of a hadron gas at T = 156 MeV. No systematic uncertainty is assigned to this procedure. In Table I the η, η′, n, and Σ entries alone sum to 1345 out of 11335, about 12% of the Pb–Pb total, with a comparable fraction in the pp tables. Because the final dS/dy and S/Nch values depend on these estimates, please propagate an uncertainty for the unmeasured-species assumption, for example by varying the hadron-gas temperature or by testing alternative matching rules, and state the resulting contribution to the total systematic uncertainty.","section":"Section III A and Table I"}],"minor_comments":[{"comment":"The text calls this a polynomial of order 8, but the sum runs only to i = 7; please clarify whether an a_8 coefficient is intended or whether the polynomial is of order 7.","section":"Section II, Eq. (8)"},{"comment":"There is a typo: 'In this section we use assume h(γ) = ...' should read 'we use' or 'we assume'.","section":"Appendix A, Eq. (A2)"},{"comment":"The pp simulation uses a single width σ = 0.6 fm and a fixed η/s = 0.08, with no sensitivity study for these choices; a brief statement of how the reconstructed temperature and the '5% after 1 fm/c' conclusion respond to varying σ and η/s would help the reader assess the model dependence.","section":"Section V B"},{"comment":"The comparison with hadron-resonance-gas models mixes a data-based S/Nch that sums a limited set of final-state species with model S/Nch values that sum all primary hadrons before decays; the text acknowledges this difference but does not quantify how much of the 1–2σ discrepancy it can explain. A numerical estimate would strengthen the comparison.","section":"Section IV"}],"recommendation":"major_revision","confidential_remarks":"To the editor: the principal blocking issue is the undocumented polynomial approximation in Eq. (8); once the authors supply the coefficients and a validation, or switch to direct numerical integration of the exact integrand, the pp entropy extraction is likely publishable. The self-citations (Refs. [54, 62, 63, 70]) appear in the modeling section and do not create circularity in the entropy extraction itself. The paper fits the scope of the journal and the overall method is sound; the requested changes are local rather than requiring a new analysis."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Here’s my take. The paper is a careful, data-anchored application of the Pal–Pratt entropy method to LHC pp and Pb–Pb. The headline numbers—dS/dy = 11335 ± 1188 in 0–10% Pb-Pb, 135.7 ± 17.9 in high-multiplicity pp, 37.8 ± 3.7 in MB pp—are likely to become standard references, and the S/Nch comparison with hadron-resonance-gas models is a useful tension: 6.7 ± 0.8 sits 1–2σ below the model expectations, and the pion phase-space density above unity in pp is a concrete puzzle. The method is not new, but this is the first clean application at LHC energies with modern ALICE spectra and femtoscopy. The extraction itself is honest: pT→0 extrapolations are bracketed with several functional forms and the spread is propagated; HBT radii are parametrized two ways; feed-down is simulated and corrected; and the integrated yields are checked against ALICE. The citation pattern looks clean; the self-cited KøMPøST enters only in the modeling half, so there is no circularity in the entropy extraction.\n\nThe soft spots are exactly where the reader put them. First, Eq. (8): the order-8 polynomial replacing (1+f)ln(1+f) for pions in pp is given without coefficients, fit interval, maximum F, or error estimate. The Taylor series in Eq. (2) has unit radius of convergence, F exceeds unity for low-pT pions, and pions contribute about half of the pp entropy, so this unvalidated approximation sits directly under the headline numbers. The stress-test note lands. The fix is easy—the integrand is well-defined, so the authors can integrate exactly or release the polynomial and show its error over the actual F range. As is, a referee cannot verify a 10%-level quantity. Second, the temperature profile and the “only ~5% of entropy after 1 fm/c” statement are model outputs that depend on κ_s tuned to the final entropy and on the assumed constant η/s = 0.08. The authors show the η/s = 0.16 case in Fig. 4 but attach no systematic band to the central 400 MeV or 5% numbers. These should be labeled as model-dependent estimates, not measurements. The HBT geometry assumption, Eq. (5), is actually cross-checked in Appendix A: Pb-Pb is stable and pp shifts by ~10% (1σ), so I do not see that as a red flag. Lack of code release is a minor reproducibility complaint, not a fatal one.\n\nBottom line: this paper deserves a serious referee. The entropy values are physically important and the method is transparent enough for someone to reproduce with public data and a few equations. Conditions: publish the polynomial or use exact integration, add a systematic band to the model outputs, and optionally upload the analysis code. If those are addressed, I would be happy to see it as the standard citation for dS/dy at LHC.","headline":"A careful Pal–Pratt entropy extraction for LHC pp and Pb–Pb that will likely become the reference set of values, with one reproducibility gap in the pp pion entropy polynomial and a model-dependent temperature reconstruction that needs clearer uncertainty labeling.","tokens_in":20430,"tokens_out":3467,"would_cite":true,"duration_ms":38253,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"Combining measured particle spectra with HBT source radii, the paper fixes the entropy per unit rapidity in pp and Pb-Pb collisions and concludes that in central Pb-Pb about 95% of it is already present by 1 fm/c.","keywords":["entropy production","phase-space density","Hanbury Brown-Twiss radii","quark-gluon plasma","Pb-Pb collisions","pp collisions","pre-equilibrium stage","viscous hydrodynamics"],"falsifier":"Measure, in the same multiplicity classes, the full three-dimensional HBT radii $R_{\\rm out}, R_{\\rm side}, R_{\\rm long}$ together with the one-dimensional $R_{\\rm inv}$ for pions, kaons, and protons, and check whether $R_{\\rm inv}^3/(R_{\\rm out}R_{\\rm side}R_{\\rm long})$ equals $\\gamma$ within uncertainties; the appendix's alternative fit already moves pp entropy by 10%, so a comparable measured deviation would propagate directly through $F \\propto 1/(m R_{\\rm inv}^3)$ into $dS/dy$. In pp, where the paper finds pion phase-space densities above unity, also evaluate the entropy integral with the exact Bose-Einstein expression instead of the truncated polynomial; if the difference exceeds the quoted systematic uncertainty, the pp result depends on the series truncation.","tokens_in":19090,"feed_emoji":"🔥","tokens_out":14856,"duration_ms":134924,"temperature":0.7,"pith_summary":"The paper tries to establish how much entropy is produced in proton-proton and lead-lead collisions at the Large Hadron Collider, and when during the collision it is produced. It extracts the entropy per unit rapidity $dS/dy$ directly from measured hadron spectra and Hanbury Brown-Twiss source radii, without assuming thermal equilibrium: $dS/dy = 11\\,335 \\pm 1\\,188$ for the 10% most central Pb-Pb collisions at $\\sqrt{s_{NN}} = 2.76$ TeV, $dS/dy = 135.7 \\pm 17.9$ for high-multiplicity pp collisions at $\\sqrt{s} = 7$ TeV, and $dS/dy = 37.8 \\pm 3.7$ for minimum-bias pp. The entropy per charged particle, $6.7 \\pm 0.8$ in Pb-Pb, $5.4 \\pm 0.7$ in high-multiplicity pp, and $5.2 \\pm 0.5$ in minimum-bias pp, agrees with hadron-resonance-gas models within 1-2$\\sigma$ for Pb-Pb but sits below the chemical-equilibrium prediction in pp, suggesting incomplete chemical equilibration in small systems. Feeding the final entropy into a kinetic-theory pre-equilibrium stage matched to viscous hydrodynamics, the paper finds that about 95% of the final entropy already exists by $\\tau = 1$ fm/$c$ and that the central temperature of the Pb-Pb fireball at that time is about 400 MeV. If this is right, the measured final multiplicity is primarily a probe of the pre-equilibrium phase, not of the later hydrodynamic expansion.","feed_headline":"Most collision entropy forms before 1 fm/c","feed_subtitle":"Spectra and two-particle correlations fix entropy per rapidity at 11,335; only about 5% forms later than 1 fm/c.","key_machinery":"The key machinery is the Pal-Pratt phase-space density method. For each hadron species treated as stable, the measured Lorentz-invariant spectrum $E\\,d^3N/d^3p$ and the measured one-dimensional source radius $R_{\\rm inv}$ are combined through $R_{\\rm inv}^3 \\approx \\gamma R_{\\rm out} R_{\\rm side} R_{\\rm long}$ ($\\gamma = m_T/m$) into the maximum phase-space density $F = (1/m)(2\\pi)^{3/2}/(2J+1)\\,R_{\\rm inv}^{-3}\\,E\\,d^3N/d^3p$. That $F$ is inserted into the quantum entropy integral $S = \\int d^3r\\,d^3p/(2\\pi)^3[-f\\ln f \\pm (1\\pm f)\\ln(1\\pm f)]$, expanded in powers of $F$ up to fourth order for Pb-Pb and with an eighth-order polynomial for pp pions because their phase-space density exceeds unity. The conversion $R_{\\rm inv}^3 \\approx \\gamma R_{\\rm out} R_{\\rm side} R_{\\rm long}$ is what lets a single measured radius stand for the full three-dimensional source volume; the paper checks the alternative $h(\\gamma) = \\alpha\\gamma^\\beta$ in an appendix. For the time-resolved part, the same final entropy fixes the normalization of an initial entropy profile, which is evolved through a linearized QCD kinetic-theory pre-equilibrium stage and then viscous hydrodynamics with $\\eta/s = 0.08$ to freeze-out.","core_discovery":"The central discovery, stated on the paper's own terms, is that the entropy of the final state at LHC energies can be measured rather than modeled: combining identified-particle transverse-momentum spectra with one-dimensional HBT radii $R_{\\rm inv}$ gives the phase-space density of each hadron species, and integrating the standard quantum entropy functional over that density yields $dS/dy$ at kinetic freeze-out. The paper reports $dS/dy = 11\\,335 \\pm 1\\,188$ for 0-10% central Pb-Pb at $\\sqrt{s_{NN}} = 2.76$ TeV, $dS/dy = 135.7 \\pm 17.9$ for high-multiplicity pp at $\\sqrt{s} = 7$ TeV, and $dS/dy = 37.8 \\pm 3.7$ for minimum-bias pp, with entropy per charged particle $6.7 \\pm 0.8$, $5.4 \\pm 0.7$, and $5.2 \\pm 0.5$ respectively. These $S/N_{\\rm ch}$ values are compared with hadron-resonance-gas calculations at $T_{\\rm ch} = 156$ MeV; the Pb-Pb value agrees within 1-2$\\sigma$, while the pp values are below the chemical-equilibrium predictions. When the Pb-Pb entropy is used to normalize initial conditions for a pre-equilibrium kinetic-theory stage followed by viscous hydrodynamics with $\\eta/s = 0.08$, the simulation produces only about 5% of the final entropy after $\\tau = 1$ fm/$c$, so the bulk of entropy is generated before that time, and the central temperature of the 0-10% Pb-Pb fireball at $\\tau = 1$ fm/$c$ reaches about 400 MeV (about 250 MeV for high-multiplicity pp).","pith_inferences":["Beyond the paper: applying the same entropy reconstruction to p-Pb collisions at LHC energies would directly test whether $S/N_{\\rm ch}$ keeps falling with system size, which would sharpen the case that small systems freeze out away from chemical equilibrium.","Beyond the paper: because the pp pion phase-space density exceeds unity, a fully quantum (Bose-Einstein) evaluation of the entropy integral would likely raise the pp entropy estimate; the paper's eighth-order polynomial is already a partial correction, but an exact calculation would show whether the reported pp values are the right endpoint.","Beyond the paper: if only about 5% of entropy is produced after 1 fm/c, then the shear viscosity $\\eta/s$ of the quark-gluon plasma is only weakly constrained by final multiplicities; multiplicity-based extractions of $\\eta/s$ would need to be reconsidered, while pre-equilibrium entropy production becomes the quantity to constrain.","Beyond the paper: the 10% shift in pp entropy under the fitted $h(\\gamma)$ relation suggests the pp numbers are more fragile than the Pb-Pb ones; measuring full three-dimensional HBT radii in high-multiplicity pp would settle that fragility empirically."],"forward_implications":["If the extracted final entropy is right, then the entropy per charged particle in pp collisions is below the chemically equilibrated hadron-resonance-gas value, indicating that the small system has not reached full chemical equilibrium at freeze-out.","The final-state entropy fixes the normalization of initial entropy profiles for hydrodynamic calculations; with $\\eta/s = 0.08$, the central temperature of the 0-10% Pb-Pb fireball at $\\tau = 1$ fm/$c$ is about 400 MeV.","Only about 5% of the final entropy is produced after $\\tau = 1$ fm/$c$ in Pb-Pb at $\\eta/s = 0.08$, so measurements of final multiplicity mainly constrain the pre-equilibrium stage rather than the viscous expansion.","The same spectra-plus-femtoscopy recipe yields a finite entropy in high-multiplicity pp, supporting the practice of modeling small collision systems hydrodynamically while showing that the pion phase-space density there exceeds unity, so quantum corrections matter."],"supporting_citations":[{"why":"Supplies the Pal-Pratt method that converts measured spectra and source radii into an entropy integral, the foundation of the analysis.","marker":"[4]"},{"why":"Supplies the measured pion, kaon, and proton spectra in Pb-Pb that fix the bulk of the phase-space densities.","marker":"[10]"},{"why":"Supplies the measured Lambda spectra in Pb-Pb used for the strange-baryon entropy contribution.","marker":"[11]"},{"why":"Supplies the Hanbury Brown-Twiss radii in Pb-Pb that convert spectra into source volumes.","marker":"[23]"},{"why":"Supplies the Hanbury Brown-Twiss radii in pp for both minimum-bias and high-multiplicity samples.","marker":"[22]"},{"why":"Supplies the minimum-bias pp spectra of pions, kaons, and protons entering the pp entropy estimate.","marker":"[13]"},{"why":"Supplies the high-multiplicity pp spectra of pions, kaons, and protons entering the pp entropy estimate.","marker":"[15]"},{"why":"Gives the hadron-resonance-gas entropy-per-hadron values at T = 156 MeV used for the comparison with the measured S/Nch.","marker":"[17]"},{"why":"Supplies the linearized kinetic-theory pre-equilibrium propagator used to evolve the initial energy-momentum tensor to the hydrodynamic start.","marker":"[62, 63]"},{"why":"Supplies the viscous relativistic hydrodynamics solver used to evolve the system and quantify late-time entropy production.","marker":"[64]"}],"fun_headline_variants":["Most LHC entropy forms before 1 fm/c","Entropy per rapidity measured from data alone","Pb-Pb entropy 11,335, 95% before 1 fm/c","LHC entropy production is mostly pre-equilibrium","Spectra + HBT fix entropy, most is early"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise is that the one-dimensional source radius $R_{\\rm inv}$ measures the same three-dimensional Gaussian source volume as the product of HBT radii through $R_{\\rm inv}^3 \\approx \\gamma R_{\\rm out} R_{\\rm side} R_{\\rm long}$, and that this relation (with its $m_T$ scaling) can be applied to every hadron species, including those for which only spectra are measured; if this geometric conversion is biased, the reported $dS/dy$ shifts with it because the entropy is logarithmic in $F \\propto 1/(m R_{\\rm inv}^3)$.","fun_headline_variants_meta":{"raw":{"variants":["Most LHC entropy forms before 1 fm/c","Entropy per rapidity measured from data alone","Pb-Pb entropy 11,335, 95% before 1 fm/c","LHC entropy production is mostly pre-equilibrium","Spectra + HBT fix entropy, most is early"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000761,"raw_usage":{"total_tokens":3480,"prompt_tokens":1145,"completion_tokens":2335,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":761,"completion_tokens_details":{"reasoning_tokens":2263}},"tokens_in":761,"tokens_out":2335,"duration_ms":19585,"temperature":1.0,"reasoning_tokens":2263,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-14T14:37:33.635761+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Measure, in the same multiplicity classes, the full three-dimensional HBT radii $R_{\\rm out}, R_{\\rm side}, R_{\\rm long}$ together with the one-dimensional $R_{\\rm inv}$ for pions, kaons, and protons, and check whether $R_{\\rm inv}^3/(R_{\\rm out}R_{\\rm side}R_{\\rm long})$ equals $\\gamma$ within uncertainties; the appendix's alternative fit already moves pp entropy by 10%, so a comparable measured deviation would propagate directly through $F \\propto 1/(m R_{\\rm inv}^3)$ into $dS/dy$. In pp, where the paper finds pion phase-space densities above unity, also evaluate the entropy integral with the exact Bose-Einstein expression instead of the truncated polynomial; if the difference exceeds the quoted systematic uncertainty, the pp result depends on the series truncation.","supporting_citations":[{"cited_title":"Entropy Production at RHIC","cited_arxiv_id":"nucl-th/0308077","evidence_quote":"Supplies the Pal-Pratt method that converts measured spectra and source radii into an entropy integral, the foundation of the analysis."},{"cited_title":"12 Appendix B: Two-component Glauber model In this section we recap the details of the two- component Glauber model used to generate initial condi- tions for KøMPøST evolution","cited_arxiv_id":null,"evidence_quote":"Supplies the Hanbury Brown-Twiss radii in pp for both minimum-bias and high-multiplicity samples."},{"cited_title":"TABLE II","cited_arxiv_id":null,"evidence_quote":"Supplies the high-multiplicity pp spectra of pions, kaons, and protons entering the pp entropy estimate."}],"review_version":1}