{"id":"4ec7009d-4989-4d82-8c09-0d392a027f75","arxiv_id":"2506.20975","paper_version":1,"verdict":"UNVERDICTED","confidence":"HIGH","novelty_score":3.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"A symposium paper argues that a future J/psi factory with about 10^12 decays could improve hyperon CP-violation searches and neutral-kaon CPT tests by roughly an order of magnitude.","lead":"This paper is a symposium talk that makes the case for building a dedicated J/psi factory with trillions of decays. It argues such a facility would push searches for CP violation in hyperon decays and tests of CPT with neutral kaons well beyond current limits.","discovery_kind":"review","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Projected near-SM hyperon CP sensitivity rests on the unverified assumption that BESIII's systematic errors shrink with control-sample statistics; a fixed systematic floor would invalidate the Section 2.4 claim.","rationale":"The paper is an explicitly speculative programmatic white paper, and the reader's UNVERDICTED classification is appropriate: there is no new measurement to accept or reject, and the standard formalism in Sections 2 and 3 is sound. The historical narrative (\"never any sign of saturation\") is anecdotal, not a quantitative argument, and the paper correctly labels its projections as speculation. The load-bearing point is the scaling of systematic errors. The manuscript itself flags the assumption (\"for the most part, statistical errors\") but provides no decomposition or simulation with systematics. This is a genuine soft spot because both headline numbers depend on it: the hyperon claim needs the 0.11° systematic of Eq. 16 to fall below 0.01°, and the kaon claim needs the regeneration and detector systematics of E773/CPLEAR (Eq. 42) to fall below the 0.05° statistical projection. A failure of the scaling assumption would degrade the projected sensitivities but would not invalidate the paper's overall qualitative case for a J/ψ factory, since the cited BESIII results and the general opportunities stand. Therefore the verdict should remain UNVERDICTED.","tokens_in":23881,"tokens_out":11699,"duration_ms":122198,"concrete_test":"Take the published BESIII systematic-error budget for ξP−ξS (Table 1 and refs [48,49]), classify each component as control-sample-statistics-limited or fixed (detector alignment, magnetic field, material, background model), and rescale the former by sqrt(N_BESIII/N_future) with N_future=10^13 J/ψ. If the fixed terms sum to more than 0.01°, the Section 2.4 near-SM sensitivity claim fails; this directly tests the paper's central scaling assumption. The same decomposition should be applied to the kaon CPT systematics, including the φSW input.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central quantitative claims—\"near 0.01°\" sensitivity to ξP−ξS (Section 2.4) and the order-of-magnitude CPT improvement (Section 3.4.1)—require that the dominant systematic uncertainties of a future J/ψ factory scale downward with larger control samples. The only support is the assertion in Section 2.4 that BESIII's quoted 0.1° systematic errors are \"for the most part, statistical errors associated with the numbers of control sample events.\" No decomposition of the 0.11° systematic error in Eq. 16 is given, and no systematic-error model for the proposed detector is provided. If any component is fixed by detector geometry, magnetic-field knowledge, or background topology, it becomes an irreducible floor; reaching \"near 0.01°\" from Eq. 21 requires reducing the current 0.11° systematic by more than a factor of ten, which is not demonstrated. The same issue limits the kaon CPT projection: the 0.05° statistical error from the cited simulation must be combined with the ±0.1° uncertainty on φSW from Eq. 32, which is not reduced by a larger J/ψ sample and is not addressed in the paper.","agreement_with_reader":"agree"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper is a written version of a symposium talk. It reviews the growth of J/ψ event samples from BES through BESIII and argues that a future dedicated J/ψ factory with about 10^12 J/ψ decays would open two qualitatively new measurements: (i) CP violation in strange hyperon decays, specifically ξP−ξS in Ξ decays, with a projected sensitivity near the Standard Model level of about 0.01° (Section 2.4), and (ii) CPT tests using strangeness-tagged neutral kaons from J/ψ decays, with a simulated statistical precision of 43.51° ± 0.05° on ϕSW + ΔϕCPT (Section 3.4.1, Eq. (41)), corresponding to |M_K0bar − M_K0| ≈ 4 × 10^−17 MeV. The paper assembles the standard Lee-Yang parameter formalism, the Perotti et al. spin-correlation framework, published BESIII results, and the Bell-Steinberger relation. It also discusses monochromatized beams as a route to increasing the visible J/ψ cross section.","tokens_in":24174,"tokens_out":9621,"duration_ms":103154,"significance":"The paper's historical narrative is supported by specific published examples (X(1835), η1(1855), X(2370), f0-a0 mixing), and the closing list of strangeness physics contributions is a useful reminder of the role of kaons and hyperons in constructing the Standard Model. Its main quantitative content is the extrapolation of BESIII sensitivities to a multi-trillion J/ψ sample. The hyperon CP formalism and the Bell-Steinberger relation are standard and are, for the most part, correctly presented; the use of published BESIII measurements and the explicit reliance on the BESIII-affiliated simulation of ref. [65] are transparent. The projected observables are concrete and can in principle be tested by a future experiment. However, the forward projections depend on assumptions about the scaling of systematic uncertainties and on a statistical-only simulated error; these points need to be stated and quantified. With those caveats addressed, the paper would be a credible and valuable roadmap for a J/ψ factory.","major_comments":[{"comment":"The central projection that a multi-trillion J/ψ sample could measure ξP−ξS near the 0.01° SM level depends on the assertion that BESIII's quoted 0.1° systematic errors are 'for the most part statistical errors associated with the numbers of control sample events.' This assertion is not substantiated in the manuscript: no decomposition of the 0.11° systematic error in Eq. (16) is given, and no model of irreducible systematic floors (magnetic-field mapping, detector alignment, background topologies, control-sample sizes) is provided for the proposed specialized detector. Because Eq. (21) sets a target near 0.01°, the projection requires reducing the current systematic error by more than an order of magnitude; a fixed floor of the current size would invalidate the claim. Please add a quantitative systematic-scaling argument or clearly label this as a favorable, unverified assumption.","section":"Section 2.4, Eq. (16)"},{"comment":"The simulated sensitivity ϕSW + ΔϕCPT = 43.51° ± 0.05° is quoted with statistical errors only, but extracting a CPT-violating phase from this sum requires the external input ϕSW = 43.5° ± 0.1° from Eq. (32), whose uncertainty does not decrease with J/ψ statistics. The claim of an order-of-magnitude improvement over the E773 and CPLEAR results in Eq. (42) is therefore incomplete unless the 0.1° uncertainty on ϕSW and the systematic contributions from regeneration, vertex resolution, and acceptance are included. Please provide a total error budget for the proposed measurement, or restrict the claim to statistical sensitivity.","section":"Section 3.4.1, Eq. (41)"},{"comment":"The Bell-Steinberger discussion correctly notes that the auxiliary inputs—π+π−π0, semileptonic, and especially KS→3π0—are statistics-limited and based on older data, and that future progress will require corresponding improvements in those terms. This materially qualifies the order-of-magnitude improvement claim for |M_K0bar − M_K0| made in Section 3.4.1: the Eq. (51) limit is not dominated solely by J/ψ-statistics-limited ππ phases, and no proposal is given for improving the 3π0 entry without a new φ factory. The manuscript should state which route (direct ϕ+−/ϕ00 phases versus Bell-Steinberger) is being claimed to reach the quoted mass sensitivity and quantify the required auxiliary-term improvements.","section":"Section 3.5"}],"minor_comments":[{"comment":"There are several typographical and grammatical errors, including 'amd' in Section 3.3.1, 'none the world's major particle physics developed' in Section 4, and 'of of' in the Figure 10 caption; a careful proofread is needed.","section":"Throughout"},{"comment":"The phrase 'the existing eqn. 36 limit' appears to refer to the limit quoted in Eq. (25), since Eq. (36) is the conversion formula rather than the limit itself; please correct this cross-reference to avoid confusion.","section":"Section 3.4.1"},{"comment":"The axis label 'K0decay time (tS)' is unclear; please use a dimensionless variable such as τ/τS and define it in the caption.","section":"Figure 11"},{"comment":"Reference [49] is listed as 'To be published' without an arXiv number; if a preprint is available, it should be cited so readers can verify the quoted Ξ−Ξ+ errors.","section":"References"},{"comment":"The monochromatization discussion would benefit from stating the assumed beam energy spreads that correspond to the curves in Figure 13, so that the quoted visible cross sections can be reproduced from the formulas.","section":"Appendix A"}],"recommendation":"major_revision","confidential_remarks":"This is essentially a conference-proceedings-style perspective rather than a full detector study. The quantitative claims are plausible but currently rest on a small number of unquantified assumptions: the systematic-scaling hypothesis, the external ϕSW uncertainty, and the Bell-Steinberger auxiliary-input requirements. I would ask the author to add a short 'assumptions and caveats' section or table that makes these explicit. If the journal routinely publishes roadmap or perspective papers, this fits; if it requires new technical results, the novelty is borderline. No concerns about citation ethics; the self-citations are to the relevant BESIII measurements and to a simulation paper from within the community."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"This is a symposium talk turned white paper, not a research preprint. It reviews the BES/BESII/BESIII J/psi program and argues for a future J/psi factory, with two specific proposals: a hyperon CP search using the B_CP asymmetry, and a neutral-kaon CPT test using strangeness-tagged decays. The formalism is standard and mostly quoted correctly, and the historical narrative is honest and useful. The B_CP idea is genuinely worth noting: by using the beta parameter rather than alpha, it avoids the strong-phase suppression that limits A_CP, so the projected gain is real if the systematics behave.\n\nThe soft spots are where the projections do their work. Section 2.4 asserts that BESIII's systematic errors are mostly statistical in origin because they scale with control-sample statistics, but no decomposition of the 0.11 degree error is given, and no detector-specific systematic model is provided. If any component is fixed by geometry or background topology, the near-0.01 degree SM-level sensitivity does not follow. The stress-test note has it right. The kaon section has a similar issue: the 0.05 degree statistical error from the cited simulation is quoted without combining it with the current 0.1 degree uncertainty on phi_SW, which is not reduced by more J/psi events. The paper also relies on unpublished Xi- Xi+ central values for the combined limit, which is fine as an interim statement but should be flagged. On self-citation: ref [65] is a simulation by BESIII-affiliated authors, but it is a forward projection, not a recycled measurement, so that concern is minor.\n\nThat said, the kaon section is the strongest part. The Bell-Steinberger derivation is clean, the discussion of the auxiliary terms is careful, and the observation that the KLOE 3pi0 limit will become the bottleneck is a good catch. The reader's verdict of 'unverdictable' is accurate for a research result, but this is a white paper, and judged as a white paper it is a competent case for a future facility.\n\nThe audience is people planning a super tau-charm factory or a specialized J/psi factory, and anyone wanting a compact summary of what BESIII has done with 10 billion J/psi. I would not cite it in the next year, but I would bring it to a reading group if the topic is future facilities. It deserves a serious referee: the scaling assumption needs to be challenged, but the paper is honest enough that a referee can do that productively.","headline":"A competent white paper for a J/psi factory, but the flagship sensitivities rest on unverified systematic-scaling assumptions that need to be stated as assumptions.","tokens_in":24664,"tokens_out":3061,"would_cite":false,"duration_ms":29844,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"A future J/psi factory could measure the strange-hyperon weak-phase difference near the Standard Model level of 0.01 degrees and improve the neutral-kaon CPT limit by an order of magnitude.","keywords":["J/psi physics","hyperon CP violation","Lee-Yang parameters","CPT invariance","neutral kaon mixing","Bell-Steinberger relation","strangeness tagging","e+e- collider monochromatization"],"falsifier":"A complete end-to-end Monte Carlo of $10^{12}$ $J/\\psi$ decays through a realistic high-rate detector would settle the claims: if the fitted uncertainty on $\\phi_{\\rm SW}+\\Delta\\phi_{\\rm CPT}$ does not approach $0.05^\\circ$, or if the hyperon weak-phase difference retains a systematic floor above about $0.1^\\circ$ when control samples are scaled up a thousandfold, the two headline projections are not realizable.","tokens_in":23669,"feed_emoji":"⚛️","tokens_out":16041,"duration_ms":159598,"temperature":0.7,"pith_summary":"This paper argues that the $J/\\psi$ is not a finished dataset: three decades of running at the peak showed that every order-of-magnitude increase in $J/\\psi$ events produced new discoveries and new physics topics, with no sign of saturation. The forward-looking claim is that a future facility producing multi-trillion $J/\\psi$ events, in a detector tailored to the task, could do qualitatively new things in two areas that general-purpose colliders have set aside. It could measure the CP-violating weak-phase difference in $\\Xi$ decays, $\\xi_P - \\xi_S$, near the Standard Model value of about $-0.01^\\circ$, instead of today's $0.94^\\circ$ upper limit. It could also use strangeness-tagged neutral kaon decays from $10^{12}$ $J/\\psi$ decays to determine $\\phi_{\\rm SW} + \\Delta\\phi_{\\rm CPT}= 43.51^\\circ \\pm 0.05^\\circ$, corresponding to $|M_{\\bar K^0} - M_{K^0}| \\approx 4\\times10^{-17}$ MeV, an order of magnitude past the best existing CPT limit. These two numbers are the paper's quantitative answer to the perennial question of why more $J/\\psi$ events are needed.","feed_headline":"Trillion-J/psi factory could test hyperon CP at Standard Model levels","feed_subtitle":"Hyperon weak-phase precision near 0.01 degrees and kaon CPT near 4e-17 MeV would open new physics windows.","key_machinery":"The machinery for the hyperon claim is the entangled $J/\\psi\\to\\Xi\\bar{\\Xi}$ event, analyzed through a nine-angle spin-density-matrix formalism in which a $4\\times4$ correlation matrix $C_{\\mu\\nu}$ encodes the $\\Xi$ polarizations and spin correlations, and Lee-Yang parameters ($\\alpha_Y$, $\\beta_Y$, $\\gamma_Y$, equivalently $\\phi_Y$) are extracted from the fully correlated angular distribution. The key observable is $B^{\\Xi}_{\\rm CP}=(\\beta_\\Xi+\\beta_{\\bar\\Xi})/(\\alpha_\\Xi-\\alpha_{\\bar\\Xi})=\\tan(\\xi_P^\\Xi-\\xi_S^\\Xi)$, which the paper stresses is not suppressed by the small strong-interaction phase differences that dilute the familiar $A^{\\Lambda}_{\\rm CP}$ asymmetries. For the CPT claim, the machinery is the strangeness-tagged $K^0(\\tau)/\\bar K^0(\\tau)$ wave function, whose $K_S$-$K_L$ interference terms have opposite signs and oscillate as $\\cos(\\Delta M\\tau-\\phi_j)$; the reduced asymmetry $A'_{\\pi\\pi}$ isolates $\\phi_j=\\phi_{\\rm SW}+\\Delta\\phi_{\\rm CPT}$. The Bell-Steinberger relation $\\sum_j \\langle f_j|K_S\\rangle^*\\langle f_j|K_L\\rangle = \\tfrac12(\\Gamma_S+\\Gamma_L+2i\\Delta M)\\langle K_S|K_L\\rangle$ converts the measured channel amplitudes into an exact determination of $\\mathrm{Im}\\,\\delta$, and hence of $M_{\\bar K^0}-M_{K^0}$. On the accelerator side, monochromatization with dispersion at the interaction point is the practical enabler, raising the visible $e^+e^-\\to J/\\psi$ cross-section from 3.4 microbarns toward the full 90 microbarns.","core_discovery":"The central claim is that a specialized near-future facility with multi-trillion $J/\\psi$ decays would be a discovery machine for two precision probes that are uniquely enabled by the $J/\\psi$ event topology, not merely a statistics upgrade of the light-hadron program. For CP violation, the paper points out that $J/\\psi \\to \\Xi\\bar{\\Xi}$ events are nearly ideal: the $\\Xi$ and $\\bar{\\Xi}$ are produced back-to-back in a spin-entangled state with equal polarizations, decay in vacuum, and the proton and antiproton directions measure the $\\Lambda$ spin event by event, giving an effective polarization of one and a twentyfold sensitivity gain. The current combined limit $|\\xi_P - \\xi_S| < 0.94^\\circ$ is statistically limited, and the quoted $0.1^\\circ$ systematics are themselves mostly statistical errors from control samples, so a multi-trillion-event sample plausibly reaches the Standard Model sensitivity of about $-0.01^\\circ\\pm 0.01^\\circ$. For CPT, $10^{12}$ $J/\\psi$ decays tag roughly two billion $K^0\\to\\pi^+\\pi^-$ and $\\bar K^0\\to\\pi^+\\pi^-$ decays through the charge of the accompanying kaon; the simulated strangeness-tagged interference pattern gives $\\phi_{\\rm SW} + \\Delta\\phi_{\\rm CPT} = 43.51^\\circ \\pm 0.05^\\circ$, meaning $|M_{\\bar K^0} - M_{K^0}|\\approx 4\\times10^{-17}$ MeV. The Bell-Steinberger relation is then available to elevate this into an exact, phase-convention-independent determination of $\\mathrm{Im}\\,\\delta$, provided the auxiliary kaon decay inputs are improved in step with the $\\pi\\pi$ phases.","pith_inferences":["Beyond the paper, the decisive test of its projections is detector-dependent: a full end-to-end simulation at $10^{12}$ events that includes pile-up, trigger rates, beam backgrounds, and vertex resolution would show whether the statistical gains survive reconstruction losses.","Beyond the paper, the same strangeness-tagged sample could improve the $\\mathrm{Re}\\,\\delta$ determination from $\\Delta S=\\Delta Q$-violating semileptonic kaon decays, tightening the Bell-Steinberger global fit from a direction the $\\pi\\pi$ phase measurement does not constrain.","Beyond the paper, the 'no saturation' history is a heuristic, not a guarantee; the cleanest quantitative check of the factory concept would be a complete Bell-Steinberger Monte Carlo at $10^{12}$ events including all auxiliary channels, not just the $\\pi\\pi$ modes.","Beyond the paper, a monochromatized factory's tagged $\\eta$, $\\eta'$, and $f_0(980)$ samples would grow in proportion to the $J/\\psi$ sample, so long-standing questions about the four-quark structure of the light scalar mesons could be settled at much higher significance."],"forward_implications":["If the projected sensitivity holds, any measured $\\xi_P-\\xi_S$ above the few-hundredths-of-a-degree level would be evidence for new physics in the parity-conserving $P$-wave amplitudes of hyperon decay, since the Standard Model expectation is about $-0.01^\\circ$.","A $10^{12}$-event sample would improve the neutral-kaon CPT limit from about $4\\times10^{-16}$ MeV to about $4\\times10^{-17}$ MeV, an order of magnitude better than the 1990s regenerator and tagged-kaon measurements.","The $\\Xi\\bar{\\Xi}$ and $\\Xi^0\\bar{\\Xi}^0$ channels already deliver $\\Lambda$ CP asymmetries competitive with a sample ten times larger in $J/\\psi\\to\\Lambda\\bar\\Lambda$; at factory statistics these become independent probes with different systematics.","A rigorous Bell-Steinberger analysis at the new precision requires matching improvements in the $\\pi^+\\pi^-\\pi^0$, semileptonic, and $K_S\\to 3\\pi^0$ inputs, so the decades-old limits on those channels would otherwise become the bottleneck.","Monochromatization of the $e^+e^-$ beams could increase the visible $J/\\psi$ cross-section by a factor of ten or more without higher beam currents, making multi-trillion samples feasible at modest cost."],"supporting_citations":[{"why":"Supplies the modularized nine-dimensional spin-density-matrix distribution used to extract all hyperon decay parameters from entangled $\\Xi\\bar{\\Xi}$ events.","marker":"[42]"},{"why":"Establishes the polarization and correlation observables in entangled double-strange baryon events that the future projection builds on.","marker":"[47]"},{"why":"Provides the 327,305-event $\\Xi^0\\bar{\\Xi}^0$ sample whose $\\xi_P-\\xi_S$, $\\Delta\\phi^{\\Xi}_{\\rm CP}$, and $A^{\\Lambda}_{\\rm CP}$ values seed the combined limits.","marker":"[48]"},{"why":"Provides the 576,357-event $\\Xi^-\\bar{\\Xi}^+$ sample errors that combine with the $\\Xi^0$ results to reach $|\\xi_P-\\xi_S|<0.94^\\circ$.","marker":"[49]"},{"why":"Gives the Standard Model prediction $(\\xi_P-\\xi_S)_{\\rm SM}\\simeq -0.01^\\circ$ that defines the target sensitivity.","marker":"[40]"},{"why":"Simulation of strangeness-tagged $K\\to\\pi\\pi$ decays that produced the fitted $\\phi_{\\rm SW}+\\Delta\\phi_{\\rm CPT}=43.51^\\circ\\pm 0.05^\\circ$ for 3.8 billion tagged decays.","marker":"[65]"},{"why":"Tagged-kaon measurement whose several-million-event sample and systematic error define the baseline that the $J/\\psi$ factory would improve by an order of magnitude.","marker":"[66]"},{"why":"Regenerator-based neutral kaon phase measurement that, together with the tagged-kaon result, sets the current $|M_{\\bar K^0}-M_{K^0}|$ limit the factory would beat.","marker":"[67]"},{"why":"Supplies the Bell-Steinberger unitarity relation that turns measured channel amplitudes into an exact, phase-convention-independent determination of $\\mathrm{Im}\\,\\delta$.","marker":"[70]"},{"why":"Provides the current channel-by-channel inputs and world-average Bell-Steinberger analysis that the factory projections would supersede.","marker":"[72]"}],"fun_headline_variants":["J/psi factory to test hyperon CP near 0.01°","Trillion J/psi events to test CP and CPT at SM levels","J/psi factory: new probes for CP and CPT","Hyperon CP and kaon CPT from a J/psi factory"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The forward projections collapse if systematic uncertainties at a future $J/\\psi$ factory do not shrink with larger control samples; the paper explicitly relies on the quoted $0.1^\\circ$ systematics being mostly statistical in origin, and if a $10^{12}$-event detector instead introduces new backgrounds, trigger losses, or reconstruction inefficiencies, neither claim follows.","fun_headline_variants_meta":{"raw":{"variants":["J/psi factory to test hyperon CP near 0.01°","Trillion J/psi events to test CP and CPT at SM levels","J/psi factory: new probes for CP and CPT","Hyperon CP and kaon CPT from a J/psi factory"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000843,"raw_usage":{"total_tokens":3762,"prompt_tokens":1124,"completion_tokens":2638,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":740,"completion_tokens_details":{"reasoning_tokens":2562}},"tokens_in":740,"tokens_out":2638,"duration_ms":22542,"temperature":1.0,"reasoning_tokens":2562,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-06T22:37:50.123108+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"A complete end-to-end Monte Carlo of $10^{12}$ $J/\\psi$ decays through a realistic high-rate detector would settle the claims: if the fitted uncertainty on $\\phi_{\\rm SW}+\\Delta\\phi_{\\rm CPT}$ does not approach $0.05^\\circ$, or if the hyperon weak-phase difference retains a systematic floor above about $0.1^\\circ$ when control samples are scaled up a thousandfold, the two headline projections are not realizable.","supporting_citations":[{"cited_title":"Polarization observables in e+e− annihilation to a baryon-antibaryon pair","cited_arxiv_id":null,"evidence_quote":"Supplies the modularized nine-dimensional spin-density-matrix distribution used to extract all hyperon decay parameters from entangled $\\Xi\\bar{\\Xi}$ events."},{"cited_title":"Probing CP symmetry and weak phases with entangled double-strange baryons","cited_arxiv_id":null,"evidence_quote":"Establishes the polarization and correlation observables in entangled double-strange baryon events that the future projection builds on."},{"cited_title":"Tests of CP symmetry in entangled Ξ0-¯Ξ0 pairs","cited_arxiv_id":null,"evidence_quote":"Provides the 327,305-event $\\Xi^0\\bar{\\Xi}^0$ sample whose $\\xi_P-\\xi_S$, $\\Delta\\phi^{\\Xi}_{\\rm CP}$, and $A^{\\Lambda}_{\\rm CP}$ values seed the combined limits."},{"cited_title":"Precise Measurement of Matter-Antimatter Asymmetry with Entangled Hyperon Antihyperon pairs","cited_arxiv_id":null,"evidence_quote":"Provides the 576,357-event $\\Xi^-\\bar{\\Xi}^+$ sample errors that combine with the $\\Xi^0$ results to reach $|\\xi_P-\\xi_S|<0.94^\\circ$."},{"cited_title":"Valencia","cited_arxiv_id":null,"evidence_quote":"Gives the Standard Model prediction $(\\xi_P-\\xi_S)_{\\rm SM}\\simeq -0.01^\\circ$ that defines the target sensitivity."},{"cited_title":"Measurement of CP violation of neutral kaon system in J/ψ decay at the Super Tau-Charm Facility","cited_arxiv_id":null,"evidence_quote":"Simulation of strangeness-tagged $K\\to\\pi\\pi$ decays that produced the fitted $\\phi_{\\rm SW}+\\Delta\\phi_{\\rm CPT}=43.51^\\circ\\pm 0.05^\\circ$ for 3.8 billion tagged decays."},{"cited_title":"Apostolakis et al","cited_arxiv_id":null,"evidence_quote":"Tagged-kaon measurement whose several-million-event sample and systematic error define the baseline that the $J/\\psi$ factory would improve by an order of magnitude."},{"cited_title":"Schwingenheuer et al","cited_arxiv_id":null,"evidence_quote":"Regenerator-based neutral kaon phase measurement that, together with the tagged-kaon result, sets the current $|M_{\\bar K^0}-M_{K^0}|$ limit the factory would beat."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"Supplies the Bell-Steinberger unitarity relation that turns measured channel amplitudes into an exact, phase-convention-independent determination of $\\mathrm{Im}\\,\\delta$."},{"cited_title":"Antonelli, G","cited_arxiv_id":null,"evidence_quote":"Provides the current channel-by-channel inputs and world-average Bell-Steinberger analysis that the factory projections would supersede."}],"review_version":1}