arxiv: 2509.09736 · v3 · submitted 2025-09-10 · ⚛️ physics.acc-ph · nucl-ex

Data-driven method to estimate contamination from light ion beam transmutation at colliders

Sruthy Jyothi Das , Austin Baty This is my paper

Pith reviewed 2026-05-18 17:19 UTC · model grok-4.3

classification ⚛️ physics.acc-ph nucl-ex

keywords light ion collisionsbeam contaminationelectromagnetic dissociationdata-driven methodcontrol regionsRHICLHCquark-gluon plasma

0 comments p. Extension

The pith

A data-driven method using time dependence and ion size defines control regions to quantify beam contamination effects in light-ion collider data.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper proposes a method to evaluate contamination from electromagnetic dissociation of light ions circulating in colliders. Such dissociation creates smaller contaminant species whose time-dependent appearance and size can be used to select control regions in the data. These regions allow direct quantification of how contaminants affect physics analyses without needing precise Monte Carlo modeling of the dissociation process. The approach is illustrated with a simple model that also tests its robustness under varying conditions. Readers would care because recent and planned light-ion runs at RHIC and the LHC produce large datasets where uncontrolled contamination could distort measurements of system-size dependence in quark-gluon plasma dynamics.

Core claim

Collisions of relativistic light ions such as oxygen, neon, and magnesium have been proposed to study the system-size dependence of quark-gluon plasma dynamics. Electromagnetic dissociation of these ions while circulating in the collider produces beam contamination that is difficult to simulate precisely. A data-driven method exploits the time dependence and smaller size of contaminant ion species to define control regions that quantify potential contamination effects on physics analyses. A simple model illustrates the method and studies its robustness. The method can inform studies of recent LHC and RHIC data and could be useful for future light-ion programs.

What carries the argument

Control regions defined by time dependence and smaller ion size, which isolate and quantify contamination effects in the observed data.

If this is right

The method provides a practical way to assess contamination in existing proton-oxygen, oxygen-oxygen, and neon-neon datasets from RHIC and the LHC.
It reduces reliance on detailed simulations for estimating the impact of beam contaminants on physics results.
The approach can be applied to future light-ion running periods at the LHC and similar programs elsewhere.
Robustness can be checked by varying the model parameters that describe time dependence and size differences.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The technique could be extended by combining the time and size cuts with additional observables such as transverse momentum or particle identification to increase purity of the control regions.
Similar data-driven control regions might be developed for other accelerator facilities where beam dissociation or fragmentation creates impurities.
If contamination estimates from this method alter the observed system-size trends, it would motivate re-examination of how light-ion results are compared to heavy-ion baselines.

Load-bearing premise

Control regions selected solely by time dependence and smaller ion size will cleanly separate contamination effects from other backgrounds and beam dynamics without significant overlap.

What would settle it

Applying the defined control regions to recorded light-ion collision data and checking whether the extracted contamination level matches independent estimates obtained from simulation or from other observables such as energy or multiplicity distributions.

Figures

Figures reproduced from arXiv: 2509.09736 by Austin Baty, Sruthy Jyothi Das.

**Figure 2.** Figure 2: FIG. 2. The event rate, [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗

**Figure 3.** Figure 3: shows the input Ntrk distributions used for three time slices, t=0 hours (left), t = 0.5 hours (middle) and t = 14 hours (right). These distributions are scaled to match the respective event rates dN/dt from [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗

**Figure 4.** Figure 4: FIG. 4. The extracted OO and HeO components [PITH_FULL_IMAGE:figures/full_fig_p004_4.png] view at source ↗

**Figure 2.** Figure 2: The Ntrk distribution for OO is shown in open red markers and HeO is shown in open green markers. The sum of these distributions (which is what would actually be measured by an experiment) is shown by the blue line. The time-dependence of both of these distributions is evident after comparing the three panels: the OO collisions decay over time and the HeO collisions grow with time. This leads to a subtle… view at source ↗

**Figure 5.** Figure 5: FIG. 5. Closure test of the [PITH_FULL_IMAGE:figures/full_fig_p005_5.png] view at source ↗

**Figure 6.** Figure 6: FIG. 6. Time evolution of the total (top left) [PITH_FULL_IMAGE:figures/full_fig_p006_6.png] view at source ↗

**Figure 7.** Figure 7: FIG. 7. Schematic representations of various strategies that can be used to mitigate pileup effects when extracting beam [PITH_FULL_IMAGE:figures/full_fig_p006_7.png] view at source ↗

read the original abstract

Collisions of relativistic light ions, such as oxygen, neon, and magnesium, have been proposed as a way to examine the system-size dependence of dynamics typically associated with the quark-gluon plasma produced in collisions of heavier ions such as xenon, gold, or lead. Recent efforts at both the Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) have produced large datasets of proton-oxygen, oxygen-oxygen, and neon-neon collisions, catalyzing intense interest in experimental backgrounds associated with light-ion collisions. In particular, electromagnetic dissociation of light ions while they are circulating in a collider can result in beam contamination that is difficult to simulate precisely. Here we propose a data-driven method for evaluating the potential impact of beam contaminants on physics analyses. The method exploits the time dependence and smaller size of contaminant ion species to define control regions that can be used to quantify potential contamination effects. A simple model is used to illustrate the method and to study its robustness. This method can inform studies of recent LHC and RHIC data and could also be useful for future light-ion programs at the LHC and beyond.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

This paper proposes a data-driven method using time dependence and smaller contaminant ion size to estimate beam transmutation effects in light-ion collisions, which is a practical idea but stays at the illustrative stage.

read the letter

The main thing to know is that the authors suggest defining control regions from the time evolution and smaller size of contaminant ions to quantify contamination without heavy reliance on simulations. This targets a real background issue for the light-ion runs at RHIC and LHC that are probing system-size effects in quark-gluon plasma studies. The combination of those two control-region handles looks new compared to the simulation approaches referenced in the abstract. The simple model they use to demonstrate the method and test its robustness under varying assumptions is a clear step that shows the logic in action. The central proposal holds up as a methodological suggestion that does not overclaim cleanliness in real data. The soft spots are the lack of concrete details on data selection cuts, error propagation, and direct checks against actual collision datasets, which leaves the practical performance still preliminary. Other beam dynamics could leak into the regions, and that overlap risk is noted but not quantified beyond the model. This is for experimentalists working on recent or planned light-ion datasets who need tools to handle backgrounds in their analyses. A reader focused on collider data quality for small-system studies would get direct value from the control-region concept. It deserves a serious referee because the idea is grounded in observable differences and addresses an experimental need that simulations alone struggle with.

Referee Report

1 major / 2 minor

Summary. The manuscript proposes a data-driven method to estimate contamination from light ion beam transmutation at colliders such as RHIC and LHC. The method defines control regions by exploiting the time dependence and smaller size of contaminant ion species to quantify potential effects on physics analyses. A simple model is used to illustrate the method and to study its robustness under the stated assumptions.

Significance. If the control regions can be realized with acceptable purity, the method would provide a practical tool for assessing beam-related systematics in light-ion collision data, complementing simulations in studies of system-size dependence of quark-gluon plasma dynamics. The explicit robustness study with the simple model is a strength, as it demonstrates the approach under controlled conditions without introducing free parameters or circular fits.

major comments (1)

[Section on proposed method] Section describing the control regions: the central claim that time dependence and smaller ion size suffice to isolate contamination effects for quantification rests on the assumption of minimal overlap with other backgrounds or beam dynamics; the simple model illustrates behavior under ideal conditions but does not include a quantitative estimate or test of residual contamination levels in the control region, which is load-bearing for applying the method to real datasets.

minor comments (2)

[Abstract] The abstract is concise but could briefly note the key assumptions of the simple model (e.g., idealized time profiles or size distributions) to give readers immediate context.
[Model section] Notation for ion species and time bins is clear in the model section but would benefit from an explicit table summarizing the control-region selection criteria for reproducibility.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful reading of the manuscript and for the positive assessment that led to the recommendation of minor revision. We address the single major comment below and will incorporate the suggested clarification in the revised version.

read point-by-point responses

Referee: Section describing the control regions: the central claim that time dependence and smaller ion size suffice to isolate contamination effects for quantification rests on the assumption of minimal overlap with other backgrounds or beam dynamics; the simple model illustrates behavior under ideal conditions but does not include a quantitative estimate or test of residual contamination levels in the control region, which is load-bearing for applying the method to real datasets.

Authors: We agree that the utility of the control regions for real datasets hinges on the degree to which time dependence and ion size reduce overlap with other backgrounds. The manuscript presents the method under explicitly stated assumptions and uses the simple model solely to demonstrate the approach and its robustness in the absence of free parameters or circular fits. To address the concern, the revised manuscript will include an additional paragraph that extends the illustrative model with a small residual background component and quantifies its effect on the extracted contamination estimate. This addition will make the load-bearing assumption more transparent without altering the data-driven character of the proposal. revision: yes

Circularity Check

0 steps flagged

No significant circularity; methodological proposal is self-contained

full rationale

The paper proposes a data-driven method to estimate beam contamination by exploiting time dependence and smaller ion size to define control regions, illustrated via a simple model whose robustness is explicitly studied. No load-bearing derivation, equation, or claim reduces by construction to fitted inputs, self-citations, or prior author results; the central contribution is the suggestion of control-region definitions under stated assumptions, which remains independent and does not rename or smuggle in known results. This is the normal case of a self-contained methodological paper.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The method rests on domain assumptions about beam dynamics and contamination signatures rather than new free parameters or invented entities. No explicit free parameters are introduced in the abstract description.

axioms (1)

domain assumption Contaminant ions from electromagnetic dissociation exhibit distinct time dependence and smaller effective size compared to primary beam ions.
This premise is invoked to justify definition of control regions.

pith-pipeline@v0.9.0 · 5729 in / 1130 out tokens · 31988 ms · 2026-05-18T17:19:35.424610+00:00 · methodology

discussion (0)

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

IndisputableMonolith/Foundation/AbsoluteFloorClosure.lean reality_from_one_distinction unclear

?

unclear
Relation between the paper passage and the cited Recognition theorem.

A simple model is used to illustrate the method and to study its robustness... HG-Pythia OO + HeO

What do these tags mean?

matches: The paper's claim is directly supported by a theorem in the formal canon.
supports: The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends: The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses: The paper appears to rely on the theorem as machinery.
contradicts: The paper's claim conflicts with a theorem or certificate in the canon.
unclear: Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

Observation of suppressed charged-particle production in ultrarelativistic oxygen-oxygen collisions
nucl-ex 2025-10 unverdicted novelty 7.0

First measurement of the nuclear modification factor R_AA in OO collisions at 5.36 TeV shows suppression with a minimum of 0.69 at p_T around 6 GeV, favoring models with parton energy loss.

Reference graph

Works this paper leans on

29 extracted references · 29 canonical work pages · cited by 1 Pith paper · 12 internal anchors

[1]

Heavy Ion Collisions: The Big Picture, and the Big Questions

W. Busza, K. Rajagopal, and W. van der Schee, Ann. Rev. Nucl. Part. Sci.68, 339 (2018), arXiv:1802.04801 [hep-ph]

work page internal anchor Pith review Pith/arXiv arXiv 2018
[2]

Niida and Y

T. Niida and Y. Miake, AAPPS Bull.31, 12 (2021), arXiv:2104.11406 [nucl-ex]

work page arXiv 2021
[3]

J. W. Harris and B. M¨ uller, Eur. Phys. J. C84, 247 (2024), arXiv:2308.05743 [hep-ph]

work page arXiv 2024
[4]

Relativistic Fluid Dynamics In and Out of Equilibrium -- Ten Years of Progress in Theory and Numerical Simulations of Nuclear Collisions

P. Romatschke and U. Romatschke,Relativistic Fluid Dynamics In and Out of Equilibrium, Cambridge Mono- graphs on Mathematical Physics (Cambridge University Press, 2019) arXiv:1712.05815 [nucl-th]

work page internal anchor Pith review Pith/arXiv arXiv 2019
[5]

Collective flow and viscosity in relativistic heavy-ion collisions

U. Heinz and R. Snellings, Ann. Rev. Nucl. Part. Sci.63, 123 (2013), arXiv:1301.2826 [nucl-th]

work page internal anchor Pith review Pith/arXiv arXiv 2013
[6]

Measurement of inclusive jet cross sections in pp and PbPb collisions at sqrt(s[NN]) = 2.76 TeV

V. Khachatryanet al.(CMS), Phys. Rev. C96, 015202 (2017), arXiv:1609.05383 [nucl-ex]

work page internal anchor Pith review Pith/arXiv arXiv 2017
[7]

Measurements of the Nuclear Modification Factor for Jets in Pb+Pb Collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV with the ATLAS Detector

G. Aadet al.(ATLAS), Phys. Rev. Lett.114, 072302 (2015), arXiv:1411.2357 [hep-ex]

work page internal anchor Pith review Pith/arXiv arXiv 2015
[8]

Measurement of charged jet suppression in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV

B. Abelevet al.(ALICE), JHEP03, 013 (2014), arXiv:1311.0633 [nucl-ex]

work page internal anchor Pith review Pith/arXiv arXiv 2014
[9]

Aidala et al

C. Aidalaet al.(PHENIX), Phys. Rev. Lett.120, 062302 (2018), arXiv:1707.06108 [nucl-ex]

work page arXiv 2018
[10]

Measurements of long-range azimuthal anisotropies and associated Fourier coefficients for $pp$ collisions at $\sqrt{s}=5.02$ and $13$ TeV and $p$+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with the ATLAS detector

M. Aaboudet al.(ATLAS), Phys. Rev. C96, 024908 (2017), arXiv:1609.06213 [nucl-ex]

work page internal anchor Pith review Pith/arXiv arXiv 2017
[11]

Evidence for collective multi-particle correlations in pPb collisions

V. Khachatryanet al.(CMS), Phys. Rev. Lett.115, 012301 (2015), arXiv:1502.05382 [nucl-ex]

work page internal anchor Pith review Pith/arXiv arXiv 2015
[12]

Brewer, A

J. Brewer, A. Mazeliauskas, and W. van der Schee, in Opportunities of OO and pO collisions at the LHC(2021) arXiv:2103.01939 [hep-ph]

work page arXiv 2021
[13]

Giacaloneet al., Anisotropic Flow in Fixed- Target Pb208+Ne20 Collisions as a Probe of Quark- Gluon Plasma, Phys

G. Giacaloneet al., Phys. Rev. Lett.134, 082301 (2025), arXiv:2405.20210 [nucl-th]

work page arXiv 2025
[14]

Giacalone et al., Exploiting 20Ne Isotopes for Precision Characterizations of Collectivity in Small Systems, Phys

G. Giacaloneet al., Phys. Rev. Lett.135, 012302 (2025), arXiv:2402.05995 [nucl-th]

work page arXiv 2025
[15]

Huang (2023) arXiv:2312.12167 [nucl-ex]

S. Huang (2023) arXiv:2312.12167 [nucl-ex]. [16]Measurement of the charged particle nuclear modification factor in oxygen-oxygen collisions with CMS, Tech. Rep. (CERN, Geneva, 2025). [17]Collective flow in OO and NeNe collisions at 5.36 TeV, Tech. Rep. (CERN, Geneva, 2025). [18]Pseudorapidity distributions of charged hadrons in oxygen-oxygen collisions at...

work page arXiv 2023
[16]

Measurement of the azimuthal anisotropy of charged particles in $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV $^{16}$O$+^{16}$O and $^{20}$Ne$+^{20}$Ne collisions with the ATLAS detector

G. Aadet al.(ATLAS), (2025), arXiv:2509.05171 [nucl- ex]

work page internal anchor Pith review Pith/arXiv arXiv 2025
[17]

I. J. Abualrobet al.(ALICE), (2025), arXiv:2509.06428 [nucl-ex]

work page arXiv 2025
[18]

Waagaard, R

E. Waagaard, R. Bruce, R. A. Fernandez, H. Bar- tosik, J. M. Jowett, and N. Triantafyllou, (2025), arXiv:2508.19653 [physics.acc-ph]

work page arXiv 2025
[19]

Future physics opportunities for high-density QCD at the LHC with heavy-ion and proton beams

Z. Citronet al., CERN Yellow Rep. Monogr.7, 1159 (2019), arXiv:1812.06772 [hep-ph]

work page internal anchor Pith review Pith/arXiv arXiv 2019
[20]

Beam losses from ultra-peripheral nuclear collisions between Pb ions in the Large Hadron Collider and their alleviation

R. Bruce, S. Gilardoni, J. M. Jowett, and D. Bo- cian, Phys. Rev. ST Accel. Beams12, 071002 (2009), arXiv:0908.2527 [physics.acc-ph]

work page internal anchor Pith review Pith/arXiv arXiv 2009
[21]

Svetlichnyi, S

A. Svetlichnyi, S. Savenkov, R. Nepeivoda, and I. Pshenichnov, MDPI Physics5, 381 (2023)

work page 2023
[22]

I. A. Pshenichnov, I. N. Mishustin, J. P. Bondorf, A. S. Botvina, and A. S. Ilinov, Phys. Rev. C57, 1920 (1998), arXiv:nucl-th/9711030

work page internal anchor Pith review Pith/arXiv arXiv 1920
[23]

Summerfield, B.-N

N. Summerfield, B.-N. Lu, C. Plumberg, D. Lee, J. Noronha-Hostler, and A. Timmins, Phys. Rev. C104, L041901 (2021), arXiv:2103.03345 [nucl-th]

work page arXiv 2021
[24]

Y. Wang, S. Zhao, B. Cao, H.-j. Xu, and H. Song, Phys. Rev. C109, L051904 (2024), arXiv:2401.15723 [nucl-th]

work page arXiv 2024
[25]

Choi and H

S. Choi and H. Oh, Eur. Phys. J. C81, 643 (2021), arXiv:1906.10831 [hep-ph]

work page arXiv 2021
[26]

Kasieczka, B

G. Kasieczka, B. Nachman, M. D. Schwartz, and D. Shih, Phys. Rev. D103, 035021 (2021), arXiv:2007.14400 [hep- ph]

work page arXiv 2021
[27]

Jowettet al., LPC Presentation, Indico (2025), ac- cessed: 2025-06-15

J. Jowettet al., LPC Presentation, Indico (2025), ac- cessed: 2025-06-15

work page 2025
[28]

Loizides and A

C. Loizides and A. Morsch, Phys. Lett. B773, 408 (2017), arXiv:1705.08856 [nucl-ex]

work page arXiv 2017
[29]

Nijs and W

G. Nijs and W. van der Schee, (2025), arXiv:2507.01659 [nucl-th]

work page arXiv 2025