{"id":"a8c1047a-6f10-4d15-b47a-598bf9068a50","arxiv_id":"1908.02070","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":4.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"Ngo 80 proximity potential, with a deformed double-folding Coulomb potential, best reproduces alpha-decay half-lives for superheavy nuclei Z=106-118, and predicts ~100-second half-lives for some unmeasured isotopes.","lead":"This paper compares 28 versions of the nuclear proximity potential to calculate alpha-decay half-lives for 70 superheavy nuclei with atomic numbers 106 to 118, and finds the Ngo 80 version matches experiment best. It then predicts half-lives for unmeasured superheavy isotopes, including some with half-lives around 100 seconds, which could guide future searches for new elements.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Benchmark ranking rests on a linear-seconds SD dominated by a few long-lived nuclei; if the standard log10 half-life metric changes the ranking, the central Ngo80 claim and the predictions built on it are unsupported.","rationale":"I read the paper as a benchmark-plus-prediction study. The benchmark is foundational: the later Q_WS4 predictions are presented specifically with the Ngo80 potential, so if the ranking is an artifact, the predictive section has no clear basis. The reader's weakest_assumption targets WS4 uncertainty, which is a genuine separate issue, but the linear-seconds metric is the more elementary problem because it can be checked directly from Table III and it bears on the paper's principal comparative claim. I do not assert that the ranking certainly flips; I assert that the paper provides no valid evidence for the ranking until the log-scale comparison is shown. This is a verifiable condition, not a judgment on the physics. The paper does give enough formulas and tabulated input (Table III) for an expert to recompute the SDs, which is independent support for the proposed check. I also note secondary concerns (Q_WS4 errors enter exponentially; no explicit alpha preformation factor) and the reader already flagged Q_WS4; my verdict remains conditional on the authors addressing the log-metric ranking and propagating Q_WS4 uncertainties.","tokens_in":16277,"tokens_out":13428,"duration_ms":120076,"concrete_test":"Recompute Table II for all 70 nuclei and all 28 versions with d_i = log10(T_theo,i/T_exp,i), reporting both RMS(d_i) and mean |d_i|. If Ngo80 is no longer the smallest among full-coverage versions (gamma-MS1966 is the immediate alternative), the benchmark claim fails; if it remains smallest, the metric concern is settled. As a sensitivity check, repeat with the five longest-lived nuclei removed to show the ranking is not carried by linear-seconds outliers.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim that Ngo80 is the best proximity version is selected by Eq. (26), a standard deviation in linear seconds. The 70 half-lives in Table III span roughly 1e-6 to 1e2 s, so a linear-seconds metric is numerically controlled by the few longest-lived emitters and is nearly blind to factor-of-100 errors on short-lived nuclei. Example: for 278113, T_exp = 1.4e-3 s, Ngo80 gives 1.59e-5 s (factor ~88 low) and gamma-MS1966 gives 4.45e-6 s (factor ~315 low); both linear residuals are below 1.4e-3 s and barely contribute to SD, while one long-lived case, 285112 (T_exp = 34 s), contributes ~10 s of linear residual for Ngo80. The reported margin between Ngo80 (4.6053 s) and gamma-MS1966 (4.7238 s) is 0.12 s, much smaller than these long-lived residuals. Since the predictive section relies entirely on Ngo80, the metric choice is load-bearing; without a log10-based ranking the benchmark is not established. This is not just a style issue: half-life systematics is conventionally compared on a log scale, and the authors' own Ref. [35] uses RMS deviations on log10 half-lives.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper reports a systematic comparison of 28 versions of the proximity potential for the alpha-decay half-lives of 70 superheavy nuclei with 106<=Z<=118. The calculation uses experimental Q_alpha values, a double-folding Coulomb potential for a spherical alpha particle and a deformed daughter, WKB penetration probabilities with orientation averaging, and the standard assault-frequency formula. The authors find that the Ngo 80 version yields the smallest standard deviation, in linear seconds, from the experimental half-lives (SD = 4.6053 s versus 4.7238 s for the next full-coverage version). Using Ngo 80 and the WS4 mass-model Q_alpha values, they then predict half-lives for unmeasured isotopes, including several with half-lives around 100 s, and compare these predictions with the VSS, Royer, and UDL semi-empirical formulas.","tokens_in":16457,"tokens_out":9703,"duration_ms":97567,"significance":"Should the ranking be robust, the paper would provide a concrete recommendation among proximity interactions for practical estimates of superheavy-nucleus alpha-decay half-lives and a set of candidate alpha-decaying isotopes for future experiments. The comparison is useful as an external benchmark: none of the model parameters is fitted to the 70 half-lives, the Coulomb potential is treated with sphericity-deformation coupling, and 28 versions are tested on a common data set. The two main components of the paper are, however, load-bearing: the ranking in Table II is based on a linear-seconds standard deviation that is dominated by a few long-lived nuclei, and the predictive section rests on WS4 Q_alpha values whose uncertainties are not quantified. Both need to be addressed before the conclusions can be accepted.","major_comments":[{"comment":"The ranking of the 28 proximity potentials is made with the linear-seconds standard deviation of Eq. (26). Because the half-lives in Table III span roughly seven orders of magnitude (from about 10^-6 s to about 10^2 s), this metric is numerically controlled by the few longest-lived nuclei. For instance, for 278113 (T_exp = 1.4e-3 s) the Ngo 80 value is 1.59e-5 s, an underestimate by a factor of about 88, yet its linear contribution to the SD is below 1.4e-3 s; in contrast, 285112 (T_exp = 34 s) contributes a linear residual of order 10 s. The reported winning margin over gamma-MS 1966 is only 0.12 s, far smaller than the contribution of a single long-lived nucleus. Since the remainder of the paper, including the predictive section, is built on the choice of Ngo 80, the authors must repeat the ranking with a log10-based metric (as in their own Ref. [35]) and show that the conclusion is stable; as it stands, the central claim that Ngo 80 is the best version is not established.","section":"Section III, Eq. (26), Table II"},{"comment":"The predicted half-lives in Table V are obtained by combining the Ngo 80 potential with the WS4 Q_alpha values of Ref. [46]. Because the WKB penetrability in Eq. (15) depends exponentially on Q_alpha, an uncertainty of only 0.1-0.2 MeV in the WS4 Q_alpha changes a predicted half-life by roughly an order of magnitude. The paper cites Ref. [92] for the overall quality of WS4 in this mass region but gives no numerical uncertainty for Q_alpha and no propagation of that uncertainty into Table V. Consequently, the specific ~100 s candidates and the claimed agreement with VSS, Royer, and UDL are not yet quantitatively supported. The authors should state the accuracy of Q_WS4 for these superheavy nuclei and provide a sensitivity analysis (for example, shifting Q_alpha by +/-0.1 and +/-0.2 MeV and reporting the resulting half-life ranges).","section":"Section III, Table V, Eq. (15)"}],"minor_comments":[{"comment":"The last equality in Eq. (13) appears to omit the factor hbar that is present in the preceding expression; please state the units or convention used so that the assault frequency is dimensionally correct.","section":"Section II A, Eq. (13)"},{"comment":"The equation is printed as G = 2nr + 1 but the accompanying text defines G as 2nr + l; these must be reconciled, since Eq. (13) uses G + 3/2.","section":"Section II A, Eq. (14)"},{"comment":"The criterion for excluding versions with partial coverage is stated only as 'less than the others'; for example, Prox.00 has 60 of the 70 nuclei. Please define the inclusion threshold explicitly, since comparing SDs over different sample sizes is otherwise misleading.","section":"Section III, Table II"},{"comment":"Table IV is labeled 'continued Table III' instead of having its own caption and number; the same columns should be described in a standalone caption.","section":"Section III, Table IV"},{"comment":"The abstract says 'a exact method' and should read 'an exact method'; in addition, the word 'exact' for the Coulomb potential should be qualified, since Eq. (19) truncates the deformation expansion and the integrations in Eq. (18) are performed numerically.","section":"Abstract and Section II"}],"recommendation":"major_revision","confidential_remarks":"The main technical risk is the ranking metric: the paper's central recommendation of Ngo 80 depends entirely on a linear-seconds SD that is dominated by a few long-lived nuclei. If the authors redo the comparison on a log10 scale and quantify the sensitivity of the predictions to Q_WS4 uncertainties, the manuscript could be publishable. The external-benchmark character of the study and the breadth of the version comparison are positive features; I see no issue of novelty overlap that would need further action."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"The paper is a systematic benchmark of 28 proximity potentials for alpha-decay half-lives of Z=106-118, and it builds a plausible case that Ngo80 reproduces the measured data best. The case is not yet solid: the ranking metric is standard deviation in linear seconds, which on a dataset spanning eight orders of magnitude is dominated by a few long-lived nuclei. The predictive section also depends on WS4 Q_alpha values with no quoted uncertainty.\n\nWhat is actually new: the same group already covered Z=52-107 with 28 potentials; here they extend to the superheavy region, add a deformed double-folding Coulomb potential, and compare Ngo80 against 27 other proximity versions. They also produce a table of half-life predictions for unmeasured isotopes using WS4 energies, with comparisons to VSS, Royer, and UDL. The reproduction of measured half-lives by Ngo80 in Table III is genuinely decent; many values land within a factor of 2-5, and the WKB treatment with orientation averaging is standard. The paper is reproducible in principle; formulas and references are sufficient for an expert re-implementation.\n\nThe load-bearing soft spot is Eq. (26). A linear-seconds SD is the wrong loss function for half-lives spanning 1e-6 to 1e2 s. The stress-test example is right: 278113 with T_exp=1.4e-3 s is underpredicted by a factor of 88, but its linear residual is below 0.0014 s, while 285112 with T_exp=34 s contributes about 10 s of residual. The margin between Ngo80 (4.6053 s) and gamma-MS1966 (4.7238 s) is 0.12 s, smaller than the long-lived residuals. If you re-rank on log10 half-life residuals, the ordering may change, and the paper's central recommendation is unsupported until that check is done. The authors' own Ref. [35] used RMS on log10; they should do the same here. A related minor issue is that the SD comparison mixes versions with different numbers of nuclei (e.g., gamma-RR1984 has SD 0.1056 for 27 nuclei), so the comparison table is not apples-to-apples.\n\nThe predictive half is fragile. The WS4 Q_alpha values enter the WKB exponent, and a 0.2 MeV error changes half-lives by an order of magnitude. The paper gives no uncertainty estimate or propagation, so the claimed agreement with VSS/Royer/UDL is at best indicative. They also never state the implicit alpha preformation factor of unity, nor do they test its sensitivity.\n\nWho this is for: people working in superheavy alpha-decay systematics who want a quick comparison of proximity potential versions, and experimental groups looking for candidate isotopes. It deserves a serious referee, but with a request for major revision: redo the ranking on a log10 scale, propagate the WS4 uncertainties, and state the preformation assumption. As is, the benchmark claim is not established, but the underlying calculation and data collection are solid enough to be worth engaging with.","headline":"A useful systematic benchmark of proximity potentials for superheavy alpha decay, but the ranking metric is wrong and the predictions rest on unquantified WS4 energies.","tokens_in":17093,"tokens_out":2846,"would_cite":false,"duration_ms":28523,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":["23.60.+e","27.90.+b"],"model":"deepseek-v4-flash","headline":"Among 28 proximity-potential versions, Ngô 80 reproduces alpha-decay half-lives of superheavy nuclei best.","keywords":["alpha-decay","superheavy nuclei","proximity potential","Ngo 80","WKB approximation","double folding model","Q_WS4","half-life predictions"],"falsifier":"Measure the $\\alpha$-decay energy of a predicted long-lived isotope, for example the $A=291$, $Z=114$ nucleus with predicted half-life $3.61\\times10^2$ s and $Q_{WS4}=9.245$ MeV, and compare the measured value with the WS4 value; a discrepancy of about 0.2 MeV would move the half-life by roughly a factor of 10. A cheaper check is to recompute the paper's Table V half-lives with two independent mass models and see whether the roughly 100-second nuclei stay in the same half-life band.","tokens_in":15956,"feed_emoji":"☢️","tokens_out":15741,"duration_ms":141531,"temperature":0.7,"pith_summary":"This paper tests 28 versions of the nuclear proximity potential against measured $\\alpha$-decay half-lives for 70 superheavy nuclei with $106\\le Z\\le 118$. It combines each proximity potential with an exact double-folding Coulomb potential for a spherical $\\alpha$ particle and a deformed daughter nucleus, and computes the barrier penetrability with the WKB approximation. The authors find that the Ngô 80 version gives the smallest scatter, a standard deviation of $4.6053$ s, slightly better than the next-best full-coverage version. Using Ngô 80 with WS4 $\\alpha$-decay energies, they predict half-lives for unmeasured superheavy isotopes and identify some with half-lives near 100 seconds, which are unusually stable for nuclei outside the known stability islands. The payoff is a recommended potential for superheavy $\\alpha$-decay estimates and a concrete list of candidate relatively stable superheavy nuclei.","feed_headline":"Ngo 80 proximity potential wins 28-way test for superheavy alpha decay","feed_subtitle":"The 1980 proximity version best reproduces measured half-lives for 70 nuclei; the same potential flags long-lived superheavy isotopes.","key_machinery":"The central object is the total interaction potential $V_T(r)=V_N(r)+V_C(r)+V_l(r)$ between the $\\alpha$ particle and the deformed daughter nucleus. The nuclear part is a proximity potential; the winning version, Ngô 80, uses a universal function of the surface separation that is parabolic on one side of $s_0=-1.6$ fm and exponential on the other. The Coulomb part is computed by double folding the charge densities of a spherical $\\alpha$ and a deformed daughter, using Fermi distributions with deformation parameters $\\beta_2$ and $\\beta_4$. The half-life follows from the WKB penetrability $P$ averaged over daughter orientation, $T_{1/2}=\\ln 2/(\\nu_0 P)$, and the 28 versions are ranked by the standard deviation of their computed half-lives against the experimental values.","core_discovery":"The paper claims that, for $\\alpha$ decay of superheavy nuclei in the range $Z=106$ to $118$, the Ngô 80 version of the proximity potential is the most reliable among the 28 versions examined. With experimental $Q_\\alpha$ values for 70 nuclei, Ngô 80 yields $SD=4.6053$ s, the smallest standard deviation of any version that covers all 70 nuclei, ahead of γ-MS 1966 at $4.7238$ s and clearly ahead of the remaining versions. For isotopes without measured data, the same potential is combined with $Q_{WS4}$ $\\alpha$-decay energies to predict half-lives; several of these predictions fall near 100 seconds, and the paper reports that they agree well with the VSS, Royer, and UDL semi-empirical formulas for the same nuclei.","pith_inferences":["Because the paper does not quote uncertainties on $Q_{WS4}$, the predicted half-lives are best read as central values; recomputing them with two or three independent mass models would show whether the roughly 100-second nuclei survive as a band rather than a single-model point.","The standard-deviation margin between Ngô 80 and γ-MS 1966 is small, so a different Coulomb treatment or deformation set could reorder the top two versions; the ranking should be checked outside $Z=106$ to $118$ before being treated as universal.","A natural extension is to apply the same method to decay chains beyond $Z=118$ or to very neutron-rich superheavy isotopes, where the WS4 mass model has not yet been benchmarked against data."],"forward_implications":["Ngô 80 can be treated as the recommended proximity version for alpha-decay half-life estimates in the superheavy region whenever an experimental $Q_\\alpha$ is available.","The unmeasured isotopes listed in the paper with predicted half-lives near 100 seconds become concrete candidate nuclei for future synthesis and decay-chain identification.","The agreement among Ngô 80, VSS, Royer, and UDL for the same predicted nuclei indicates that the roughly 100-second half-lives are not an artifact of one particular potential.","The same potential-plus-$Q_{WS4}$ procedure can be rerun for neighbouring isotopes to map where the relatively stable pockets of superheavy nuclei sit."],"supporting_citations":[{"why":"It introduces the Ngô 80 proximity potential, the version the paper finds most accurate.","marker":"[70]"},{"why":"It supplies the exact double-folding Coulomb potential for spherical-deformed nuclear pairs used in the barrier calculation.","marker":"[80]"},{"why":"It provides the $\\beta_2$ and $\\beta_4$ deformation parameters for the daughter nuclei.","marker":"[81]"},{"why":"It supplies the WS4 alpha-decay energies used for all predictions on unmeasured superheavy nuclei.","marker":"[46]"},{"why":"It is the earlier comparison the paper cites to justify that $Q_{WS4}$ is reliable for $Z\\ge100$.","marker":"[92]"},{"why":"It defines the Viola-Seaborg (VSS) semi-empirical formula used as a comparison for predicted half-lives.","marker":"[83]"},{"why":"It provides the five fitted parameters used in the VSS formula.","marker":"[84]"},{"why":"It defines the Royer analytical formula used as a second comparison for predicted half-lives.","marker":"[28]"},{"why":"It defines the Universal Decay Law used as a third comparison for predicted half-lives.","marker":"[85]"},{"why":"It provides evaluated experimental data used as the 70-nucleus benchmark for the standard-deviation comparison.","marker":"[91]"}],"fun_headline_variants":["Ngô 80 potential beats 27 others for superheavy alpha decay","Superheavy alpha half-lives: Ngô 80 most accurate","Ngô 80 predicts stable superheavy isotopes with ~100-s half-lives","Alpha decay study: Ngô 80 best among 28 proximity potentials","Ngô 80 model tops superheavy alpha decay predictions"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The predictive half of the paper stands on the assumption that WS4 $\\alpha$-decay energies are accurate to roughly 0.1 to 0.2 MeV for unmeasured superheavy nuclei, because the WKB penetration probability depends exponentially on $Q_\\alpha$ and a 0.2 MeV error would change a predicted half-life by roughly an order of magnitude.","fun_headline_variants_meta":{"raw":{"variants":["Ngô 80 potential beats 27 others for superheavy alpha decay","Superheavy alpha half-lives: Ngô 80 most accurate","Ngô 80 predicts stable superheavy isotopes with ~100-s half-lives","Alpha decay study: Ngô 80 best among 28 proximity potentials","Ngô 80 model tops superheavy alpha decay predictions"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000835,"raw_usage":{"total_tokens":3632,"prompt_tokens":924,"completion_tokens":2708,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":540,"completion_tokens_details":{"reasoning_tokens":2614}},"tokens_in":540,"tokens_out":2708,"duration_ms":20636,"temperature":1.0,"reasoning_tokens":2614,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-14T14:55:22.577467+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Measure the $\\alpha$-decay energy of a predicted long-lived isotope, for example the $A=291$, $Z=114$ nucleus with predicted half-life $3.61\\times10^2$ s and $Q_{WS4}=9.245$ MeV, and compare the measured value with the WS4 value; a discrepancy of about 0.2 MeV would move the half-life by roughly a factor of 10. A cheaper check is to recompute the paper's Table V half-lives with two independent mass models and see whether the roughly 100-second nuclei stay in the same half-life band.","supporting_citations":[{"cited_title":"Royer and B","cited_arxiv_id":null,"evidence_quote":"It introduces the Ngô 80 proximity potential, the version the paper finds most accurate."},{"cited_title":"Reisdorf, Journal of Physics G: Nuclear and Particle Physics 20, 1297 (1994)","cited_arxiv_id":null,"evidence_quote":"It supplies the exact double-folding Coulomb potential for spherical-deformed nuclear pairs used in the barrier calculation."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"It supplies the WS4 alpha-decay energies used for all predictions on unmeasured superheavy nuclei."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"It is the earlier comparison the paper cites to justify that $Q_{WS4}$ is reliable for $Z\\ge100$."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"It defines the Viola-Seaborg (VSS) semi-empirical formula used as a comparison for predicted half-lives."},{"cited_title":"Blocki and W","cited_arxiv_id":null,"evidence_quote":"It provides the five fitted parameters used in the VSS formula."},{"cited_title":"Royer and R","cited_arxiv_id":null,"evidence_quote":"It defines the Royer analytical formula used as a second comparison for predicted half-lives."},{"cited_title":"Ismail, WM","cited_arxiv_id":null,"evidence_quote":"It defines the Universal Decay Law used as a third comparison for predicted half-lives."},{"cited_title":null,"cited_arxiv_id":null,"evidence_quote":"It provides evaluated experimental data used as the 70-nucleus benchmark for the standard-deviation comparison."}],"review_version":1}