J/psi production as a function of charged-particle multiplicity in pp collisions at sqrt{s} = 5.02 TeV with ALICE
Pith reviewed 2026-05-25 16:55 UTC · model grok-4.3
The pith
Relative J/ψ yield increases linearly with charged-particle multiplicity in 5.02 TeV pp collisions at forward rapidity.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The relative J/ψ yields as a function of relative charged-particle multiplicity exhibit a linear increase in pp collisions at √s = 5.02 TeV measured at forward rapidity. Comparison with measurements at √s = 13 TeV shows that this increase is independent of collision energy but depends strongly on the rapidity gap between the J/ψ and multiplicity measurements.
What carries the argument
The ratio of J/ψ yield in a given multiplicity class to the average yield, plotted against the relative multiplicity, measured in the forward region.
Load-bearing premise
That the J/ψ and multiplicity measurements at different rapidities and energies are comparable without large uncorrected systematic effects from detector acceptance or analysis choices.
What would settle it
A measurement at a third energy, such as 7 TeV, showing a different slope for the multiplicity dependence would falsify the energy-independence claim.
read the original abstract
The relative J/$\psi$ yields as a function of relative charged-particle multiplicity in pp collisions at $\sqrt{s}$ = 5.02 TeV, measured at forward rapidity, are investigated for the first time. A linear increase of the relative J/$\psi$ yield with respect to multiplicity is observed. A comparison of the findings of the present work with the available ALICE measurements obtained in pp collisions at $\sqrt{s}$ = 13 TeV at forward and mid-rapidity indicates that the increase of J/$\psi$ with multiplicity is independent of energy but exhibits a strong dependence on the rapidity gap between the J/$\psi$ and multiplicity measurements. The results are compared with theoretical model calculations.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript reports the first measurement of relative J/ψ yields as a function of relative charged-particle multiplicity in pp collisions at √s = 5.02 TeV at forward rapidity with ALICE. It observes a linear increase and compares the results to prior ALICE measurements at √s = 13 TeV (forward and mid-rapidity) to conclude that the multiplicity dependence is independent of collision energy but exhibits a strong dependence on the rapidity gap between the J/ψ and multiplicity measurements. The data are also compared to theoretical models.
Significance. If the cross-energy and cross-rapidity comparisons are shown to be robust, the result constrains models of charmonium production in high-multiplicity pp events by isolating the role of rapidity correlations versus energy. The experimental measurement itself is a straightforward extension of established ALICE techniques and supplies new data points for model testing.
major comments (1)
- [Results/comparison section] Results/comparison section: The central claim that the J/ψ multiplicity dependence is energy-independent but rapidity-gap-dependent rests on quantitative comparison of the 5.02 TeV forward-rapidity slope with the 13 TeV forward- and mid-rapidity slopes. The manuscript does not provide an explicit demonstration (e.g., a table or dedicated paragraph) that the relative multiplicity estimator is defined over identical pseudorapidity intervals, that pile-up and vertexing corrections are applied consistently, or that residual detector-response differences have been quantified and shown not to mimic a rapidity-gap effect. Without this, the slope comparison that underpins the energy-independence statement cannot be evaluated.
minor comments (1)
- [Abstract] The abstract states the main observations but omits any mention of statistical significance, systematic uncertainties, or the size of the multiplicity bins; adding a single sentence summarizing these would improve clarity for readers.
Simulated Author's Rebuttal
We thank the referee for the constructive review. The major comment identifies a need for explicit documentation supporting the cross-energy and cross-rapidity slope comparisons. We address this below and will revise the manuscript accordingly.
read point-by-point responses
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Referee: The central claim that the J/ψ multiplicity dependence is energy-independent but rapidity-gap-dependent rests on quantitative comparison of the 5.02 TeV forward-rapidity slope with the 13 TeV forward- and mid-rapidity slopes. The manuscript does not provide an explicit demonstration (e.g., a table or dedicated paragraph) that the relative multiplicity estimator is defined over identical pseudorapidity intervals, that pile-up and vertexing corrections are applied consistently, or that residual detector-response differences have been quantified and shown not to mimic a rapidity-gap effect. Without this, the slope comparison that underpins the energy-independence statement cannot be evaluated.
Authors: We agree that an explicit demonstration would strengthen the manuscript. In the revised version we will add a dedicated paragraph (and accompanying table) in the Results/comparison section that: (i) states the pseudorapidity acceptance used for the multiplicity estimator in each dataset (|η|<1 for the mid-rapidity measurement and the corresponding forward intervals for the others), confirming they match the definitions in the cited 13 TeV publications; (ii) notes that pile-up rejection, vertex reconstruction, and event-selection criteria follow the identical ALICE procedures documented in those references; and (iii) summarizes the evaluation of residual detector-response differences (via Monte Carlo closure tests and data-driven checks) showing that any such effects are smaller than the quoted uncertainties and do not alter the observed slope ordering with rapidity gap. These additions will allow the reader to evaluate the robustness of the energy-independence statement directly. revision: yes
Circularity Check
Pure experimental measurement; no derivation or self-referential fitting
full rationale
The paper reports direct measurements of relative J/ψ yields as a function of relative charged-particle multiplicity at forward rapidity in 5.02 TeV pp collisions. The central claims consist of an observed linear trend and a comparison to prior ALICE datasets at 13 TeV. No equations derive a quantity from fitted parameters that are then re-used as a prediction, no ansatz is smuggled via self-citation, and no uniqueness theorem or self-citation chain is invoked to force the result. The analysis is a self-contained empirical observation against external data, qualifying for score 0 under the rules.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
- [1]
- [2]
-
[3]
S. G. Weber (ALICE Collaboration), (2017) [arXiv:1704.04735 [hep-ex]]
work page internal anchor Pith review Pith/arXiv arXiv 2017
-
[4]
and others (ALICE Collaboration), Phys
Adamov, D. and others (ALICE Collaboration), Phys. Lett. B776, 91-104 (2018)
work page 2018
- [5]
- [6]
-
[7]
S. G. Weber, A. Dubla, A. Andronic and A. Morsch, (2018) arXiv:1811.07744 [nucl-th]
work page internal anchor Pith review Pith/arXiv arXiv 2018
-
[8]
B. Z. Kopeliovich et al., Phys. Rev. D88, 116002 (2013) [arXiv:1308.3638 [hep-ph]]
work page internal anchor Pith review Pith/arXiv arXiv 2013
-
[9]
E. G. Ferreiro and C. Pajares, Phys. Rev. C86, 034903 (2012) [arXiv:1203.5936 [hep-ph]]
work page internal anchor Pith review Pith/arXiv arXiv 2012
discussion (0)
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