{"id":"73817e43-733c-475b-9dc3-53442774f579","arxiv_id":"2606.09760","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":5.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":0,"one_line_summary":"In magnetized expanding QGP the Einstein-de Haas effect produces time-growing angular velocity that is substantial near the crossover temperature and exhibits a nontrivial crossing between spin-dominated and inertia-dominated regimes.","lead":"The paper computes the angular velocity from the Einstein-de Haas effect in an expanding quark-gluon plasma using a quasiparticle model, finding it grows with time and becomes substantial near the crossover temperature with a regime-crossing point. A smart generalist might read it to see how magnetic fields could induce collective rotation in extreme QCD matter relevant to heavy-ion experiments.","discovery_kind":"unclear","skeptic_critique":{"model":"grok-4.3","headline":"Quasiparticle model assumptions on spin-orbital competition lack cross-validation","rationale":"The reader's weakest_assumption directly identifies the load-bearing point. Because the paper is a model calculation with no formal verification or external cross-checks cited, the concern is internal to the construction rather than a consensus mismatch. Adjusting to CONDITIONAL reflects that the claim can be retained only if the QPM results survive replacement by another microscopic model.","tokens_in":1705,"tokens_out":296,"duration_ms":9992,"concrete_test":"Recompute the ω_EdH(τ,T) curves and crossing temperature using an independent framework (e.g., NJL model with same magnetic-field coupling and identical hydrodynamic background); if the crossing shifts by >20% or disappears, the regime-separation claim is model-dependent.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"The central claim of a nontrivial crossing temperature separating spin-dominated from inertia-dominated regimes, plus substantial ω_EdH near crossover, requires that the QPM correctly encodes both the magnetic-field-induced spin polarization (via effective quark masses or couplings) and the competing orbital inertia throughout the Bjorken-like expansion. The abstract and reader's weakest_assumption indicate this balance is computed inside a single parametrized model; any mismatch between the model's T-dependent spin susceptibility and the true QCD response would move or eliminate the reported crossing and suppress the claimed magnitude of ω_EdH.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The paper investigates the Einstein-de Haas effect in a dynamically expanding magnetized quark-gluon plasma within a quasiparticle model (QPM). It computes the induced angular velocity ω_EdH(T, τ, R), reporting that ω_EdH grows with proper time τ (hence suppressed at higher T), attains substantial magnitude near the QGP crossover, and exhibits a nontrivial crossing between strong- and weak-field regimes that separates a spin-dominated regime from an inertia-dominated regime of magnetic-field-induced rotation. The findings are presented as a manifestation of angular momentum conservation in magnetized QCD matter.","tokens_in":1821,"tokens_out":581,"duration_ms":17879,"significance":"If robust, the work supplies a dynamical calculation of spin-to-orbital angular-momentum transfer in the QGP and identifies distinct regimes controlled by the competition between spin alignment and rotational inertia. The time-dependent Bjorken-like expansion adds realism beyond static treatments and could inform interpretations of global polarization or vorticity observables in heavy-ion collisions.","major_comments":[{"comment":"The central claim of a nontrivial crossing temperature and substantial ω_EdH near the crossover rests on the QPM simultaneously encoding both the magnetic-field-induced spin polarization (via effective quark masses/couplings) and the competing orbital inertia throughout the expansion. Because these ingredients are typically fitted to lattice data, the reported crossing and magnitude are outputs of the same parametrization rather than independent predictions; a mismatch between the model's T-dependent spin susceptibility and the true QCD response would shift or eliminate the crossing. No sensitivity analysis to the QPM parameters or comparison against alternative models (e.g., NJL or PNJL) is provided to test robustness.","section":"Model and results sections (implicit in abstract and methods)"},{"comment":"The abstract and results state that ω_EdH attains a 'substantial, non-negligible magnitude' near the crossover and that a 'nontrivial crossing' separates regimes, yet no numerical values, error estimates, or explicit dependence on the magnetic-field strength are supplied. Without these, it is impossible to judge whether the crossing is load-bearing or an artifact of the chosen parameter set.","section":"Abstract and numerical results"}],"minor_comments":[{"comment":"The abstract would benefit from at least one quantitative statement (e.g., the approximate value of ω_EdH or the crossing temperature) to allow readers to assess the claimed magnitude without reading the full text.","section":"Abstract"},{"comment":"Notation for the fireball radius R and its time evolution should be defined explicitly when first introduced, as it enters the inertia term that competes with spin alignment.","section":"Model setup"}],"recommendation":"major_revision","confidential_remarks":null},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for the detailed and constructive report. The two major comments raise valid points about the dependence of our results on the quasiparticle model (QPM) parametrization and the need for more quantitative information. We address each below and will revise the manuscript to strengthen the presentation.","responses":[{"response":"We agree that the robustness of the crossing temperature and the magnitude of ω_EdH with respect to QPM parameter choices requires explicit demonstration. In the revised manuscript we will add a dedicated subsection performing a sensitivity analysis: we vary the effective quark mass and coupling parameters within the ranges that still reproduce lattice thermodynamics (including magnetic susceptibility data) and recompute the crossing point and ω_EdH values. We will also include a brief qualitative comparison with existing NJL/PNJL calculations of spin polarization in magnetized matter to indicate that the competition between spin alignment and rotational inertia is not an artifact of the QPM alone. These additions directly address the concern that the reported features are tied to a single parametrization.","revision_made":"yes","referee_comment":"The central claim of a nontrivial crossing temperature and substantial ω_EdH near the crossover rests on the QPM simultaneously encoding both the magnetic-field-induced spin polarization (via effective quark masses/couplings) and the competing orbital inertia throughout the expansion. Because these ingredients are typically fitted to lattice data, the reported crossing and magnitude are outputs of the same parametrization rather than independent predictions; a mismatch between the model's T-dependent spin susceptibility and the true QCD response would shift or eliminate the crossing. No sensitivity analysis to the QPM parameters or comparison against alternative models (e.g., NJL or PNJL) is provided to test robustness."},{"response":"We accept that the abstract and main text should supply concrete numbers. The revised version will include: (i) explicit values of ω_EdH (in appropriate units) evaluated at the crossover temperature for several proper times and fireball radii; (ii) the magnetic-field dependence of both the crossing temperature and the peak ω_EdH, shown either in a new figure or table for representative eB values in the range 0.1–1 GeV²; and (iii) a short discussion of uncertainties arising from the QPM parameter variations (to be quantified in the new sensitivity analysis). These quantitative elements will allow readers to assess the physical significance of the reported effects.","revision_made":"yes","referee_comment":"The abstract and results state that ω_EdH attains a 'substantial, non-negligible magnitude' near the crossover and that a 'nontrivial crossing' separates regimes, yet no numerical values, error estimates, or explicit dependence on the magnetic-field strength are supplied. Without these, it is impossible to judge whether the crossing is load-bearing or an artifact of the chosen parameter set."}],"tokens_in":1423,"tokens_out":609,"duration_ms":16889,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The main thing here is that the authors take the classical Einstein-de Haas effect, put it inside a quasiparticle description of magnetized QGP, and track the induced angular velocity through a Bjorken-style expansion. They report that ω_EdH grows with proper time, stays suppressed at high temperature, reaches a noticeable size near the crossover, and shows a crossing between strong- and weak-field regimes that marks the shift from spin-dominated to inertia-dominated rotation.\n\nWhat is actually new is the explicit proper-time and radius dependence in the evolving fireball. Earlier work on EdH in QCD matter stayed more static; adding the expansion lets them follow how the effect builds and where the regime change occurs. The setup is internally consistent within the model and the angular-momentum conservation argument is laid out plainly.\n\nThe soft spot is exactly the one the stress-test note flags. Both the spin polarization and the orbital inertia come from the same temperature-dependent quasiparticle masses and couplings, which are fitted to lattice or other data. The crossing temperature and the claimed magnitude are therefore outputs of that fitting rather than independent results. Without a cross-check of the model’s magnetic susceptibility against lattice QCD or other approaches, it is hard to know whether the crossing survives a different parametrization or a more microscopic treatment. The abstract gives no equations, error bars, or validation steps, so the quantitative claims rest on unexamined model assumptions.\n\nThis paper is for the small group working on spin and angular momentum in heavy-ion collisions who want to see one possible mechanism explored in a dynamical setting. A reader already familiar with quasiparticle models can extract the idea quickly, but anyone outside that niche will need the model details checked first.\n\nI would send it to peer review. The calculation is concrete, the claim is specific, and referees can test the model dependence directly.","headline":"The paper computes EdH angular velocity in an expanding QGP via quasiparticle model and locates a crossing temperature between spin and inertia regimes.","tokens_in":2312,"tokens_out":447,"would_cite":false,"duration_ms":16858,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.3","headline":"The Einstein-de Haas effect produces substantial induced rotation in expanding magnetized quark-gluon plasma near the crossover temperature.","keywords":["Einstein-de Haas effect","quark-gluon plasma","magnetic field","angular momentum","quasiparticle model","QGP crossover","heavy-ion collisions"],"falsifier":"If heavy-ion collision data show no significant induced rotation near the QGP crossover temperature or no crossing between strong and weak field regimes in the angular velocity, the central claim would be contradicted.","tokens_in":2596,"feed_emoji":"🔄","tokens_out":610,"duration_ms":15032,"temperature":0.7,"pith_summary":"The paper applies a quasiparticle model to a dynamically expanding quark-gluon plasma in a magnetic field to calculate the angular velocity induced by the Einstein-de Haas effect. It finds that this angular velocity increases with proper time during expansion and becomes large near the QGP crossover temperature. A crossing point between strong and weak magnetic field regimes marks the shift from spin-driven to inertia-limited rotation. This shows the EdH effect arises from angular momentum conservation in QCD matter.","feed_headline":"EdH effect drives rotation in expanding QGP near crossover","feed_subtitle":"Angular velocity grows with time and crosses from spin-dominated to inertia-dominated regime under magnetic field.","key_machinery":"The Einstein-de Haas effect, which converts spin alignment in a magnetic field into collective mechanical rotation through conservation of total angular momentum.","core_discovery":"Using the quasiparticle model for an evolving QGP, the EdH-induced angular velocity ω_EdH grows with proper time and is suppressed at higher temperatures. Near the crossover temperature it reaches substantial magnitude. A nontrivial crossing separates strong and weak field regimes, distinguishing a spin-dominated regime from an inertia-dominated regime of magnetic field-induced rotation, thereby establishing the EdH effect as angular momentum conservation in magnetized QCD matter.","pith_inferences":["The induced rotation could produce measurable effects on azimuthal particle distributions in heavy-ion experiments.","The crossing temperature offers a potential signature for distinguishing magnetic field regimes in QCD matter.","Extensions incorporating viscosity or different equations of state could test how the regime separation persists under more realistic dynamics."],"forward_implications":["ω_EdH grows with proper time during the fireball expansion.","ω_EdH is suppressed at higher temperatures but attains substantial magnitude near the QGP crossover temperature.","A nontrivial crossing between strong and weak magnetic field regimes separates a spin-dominated regime from an inertia-dominated regime.","The EdH effect is established as a manifestation of angular momentum conservation in magnetized QCD matter."],"fun_headline_variants":["EdH rotation grows with time in expanding QGP","EdH shows spin-inertia crossing in magnetized QGP","Substantial EdH angular velocity near QGP crossover","EdH effect separates spin and inertia regimes in QGP"],"cache_read_input_tokens":2112,"weakest_assumption_plain":"The quasiparticle model accurately captures both the spin alignment under magnetic field and the competition between spin and orbital angular momentum contributions throughout the dynamical expansion of the fireball.","fun_headline_variants_meta":{"raw":{"variants":["EdH rotation grows with time in expanding QGP","EdH shows spin-inertia crossing in magnetized QGP","Substantial EdH angular velocity near QGP crossover","EdH effect separates spin and inertia regimes in QGP"]},"model":"grok-4.3","cost_usd":0.007679,"raw_usage":{"total_tokens":3493,"prompt_tokens":628,"num_sources_used":0,"completion_tokens":64,"cost_in_usd_ticks":76787000,"prompt_tokens_details":{"text_tokens":628,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":2801,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":628,"tokens_out":64,"duration_ms":16742,"temperature":1.0,"reasoning_tokens":2801,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-06-27T15:49:52.761875+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"If heavy-ion collision data show no significant induced rotation near the QGP crossover temperature or no crossing between strong and weak field regimes in the angular velocity, the central claim would be contradicted.","supporting_citations":[],"review_version":1}