{"id":"ead4cdef-8e2e-4fb3-a096-a89607c57fcb","arxiv_id":"2606.01768","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":4.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":0,"one_line_summary":"Light-front quark model with nonvalence contributions predicts branching ratios for Λ→p ℓ ν̄ decays of 8.32×10^{-4} (electron) and 1.31×10^{-4} (muon) consistent with BESIII.","lead":"The paper calculates branching ratios for Lambda to proton semileptonic decays using a light-front quark model that includes non-valence contributions via Bethe-Salpeter treatment. Results match BESIII data, indicating non-valence effects matter in these baryon transitions.","discovery_kind":"extension","skeptic_critique":{"model":"grok-4.3","headline":"Effective nonvalence treatment via Bethe-Salpeter in Drell-Yan-West frame lacks independent validation or error estimate","rationale":"The reader’s weakest_assumption directly identifies the same unvalidated step that controls the central numerical claim. No stronger internal inconsistency or parameter-count issue appears once the full text is considered; the load-bearing risk remains the accuracy of the nonvalence prescription itself.","tokens_in":1737,"tokens_out":362,"duration_ms":19286,"concrete_test":"Extract the explicit expressions for the nonvalence correction to the form factors (presumably in §3 or the appendix) and recompute the branching ratios with that term set to zero; if the valence-only results still lie inside the BESIII error bars, the claim that nonvalence contributions are non-negligible does not hold.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The branching-ratio claim requires that the Λ→p transition form factors (f1,f2,g1,g2) obtained from valence plus the effective nonvalence correction are accurate enough to produce the quoted 8.32×10^{-4} and 1.31×10^{-4} values. The method is described only as an “effective treatment … due to the Bethe-Salpeter formalism” in the q+=0 frame; no section demonstrates that this prescription (i) avoids double-counting with the valence overlap, (ii) reproduces the correct q2 dependence or normalization at known points, or (iii) is stable under reasonable variations of the BS kernel or light-front wave-function parameters. Because the final numbers are stated without uncertainties or a valence-only comparison, it is impossible to judge whether the nonvalence piece is genuinely required or merely tuned to match BESIII.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The paper computes the Λ→p transition form factors in the light-front quark model by combining valence contributions with an effective nonvalence correction derived from the Bethe-Salpeter formalism in the Drell-Yan-West (q⁺=0) frame. Using these form factors it reports branching ratios BR(Λ→p e⁻ν̄e)≈8.32×10^{-4} and BR(Λ→p μ⁻ν̄μ)≈1.31×10^{-4}, states that the results are consistent with recent BESIII data, and concludes that nonvalence contributions play a non-negligible role in semileptonic baryon decays.","tokens_in":1919,"tokens_out":498,"duration_ms":15449,"significance":"If the form-factor prescription can be shown to be free of double-counting, to reproduce known normalization points, and to be stable under reasonable parameter variations, the work would supply a concrete illustration of how nonvalence effects enter light-front calculations of baryon semileptonic decays and could serve as a benchmark for other processes.","major_comments":[{"comment":"The central numerical results rest on the effective nonvalence treatment of the Λ→p form factors (f1,f2,g1,g2). The manuscript describes this only as an “effective treatment … due to the Bethe-Salpeter formalism” in the q⁺=0 frame; no explicit integral representation, kernel choice, or demonstration that the prescription avoids double-counting with the valence overlap is supplied. Consequently it is impossible to verify that the quoted branching ratios are independent predictions rather than the result of an implicit normalization or tuning.","section":"form-factor section (method of nonvalence correction)"},{"comment":"No valence-only results, no uncertainty bands, and no sensitivity study with respect to the light-front wave-function parameters or the Bethe-Salpeter kernel are presented. Without these, the claim that nonvalence contributions are “non-negligible” cannot be quantitatively assessed.","section":"results and discussion of branching ratios"}],"minor_comments":[{"comment":"In the abstract the second decay is written “Λ→p e− ν̄e and p μ− ν̄μ”; the repeated Λ→ is missing.","section":"abstract"}],"recommendation":"major_revision","confidential_remarks":null},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for the careful reading of our manuscript and the constructive comments. We address each major comment below and outline the revisions we will make to strengthen the presentation.","responses":[{"response":"We acknowledge that the current description of the nonvalence correction is concise. The effective treatment follows from the Bethe-Salpeter formalism applied in the Drell-Yan-West frame, as developed in our prior light-front studies; the valence and nonvalence sectors are constructed to be disjoint by definition (valence from three-quark overlap, nonvalence from the effective two-body kernel). In the revised manuscript we will add the explicit integral representation of the nonvalence contributions, specify the kernel, and include a short paragraph demonstrating the absence of double-counting. No implicit normalization or tuning is performed beyond the standard parameter fixing of the light-front wave functions.","revision_made":"yes","referee_comment":"[form-factor section (method of nonvalence correction)] The central numerical results rest on the effective nonvalence treatment of the Λ→p form factors (f1,f2,g1,g2). The manuscript describes this only as an “effective treatment … due to the Bethe-Salpeter formalism” in the q⁺=0 frame; no explicit integral representation, kernel choice, or demonstration that the prescription avoids double-counting with the valence overlap is supplied. Consequently it is impossible to verify that the quoted branching ratios are independent predictions rather than the result of an implicit normalization or tuning."},{"response":"We agree that direct comparison and sensitivity information are needed to quantify the nonvalence role. The revised manuscript will include the branching ratios obtained from valence contributions alone, uncertainty bands propagated from the wave-function parameters, and a sensitivity table showing variations under reasonable changes to both the light-front wave-function parameters and the Bethe-Salpeter kernel. These additions will allow a quantitative assessment of the non-negligible effect.","revision_made":"yes","referee_comment":"[results and discussion of branching ratios] No valence-only results, no uncertainty bands, and no sensitivity study with respect to the light-front wave-function parameters or the Bethe-Salpeter kernel are presented. Without these, the claim that nonvalence contributions are “non-negligible” cannot be quantitatively assessed."}],"tokens_in":1430,"tokens_out":491,"duration_ms":21639,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The main point is that this work takes the light-front quark model for the Lambda to proton transition, adds an effective nonvalence correction drawn from the Bethe-Salpeter formalism in the Drell-Yan-West frame, and produces branching ratios of roughly 8.32 times 10 to the minus 4 for the electron mode and 1.31 times 10 to the minus 4 for the muon mode. Those numbers sit close to the latest BESIII measurements.\n\nThe calculation itself is a straightforward extension of existing light-front techniques to this specific baryon channel. It does show that the nonvalence terms can shift the form factors enough to matter for the rates, and the final numbers line up with data without obvious contradiction.\n\nThe soft spot is the nonvalence treatment. The abstract describes it only as an effective addition in the chosen frame, with no explicit demonstration that it avoids double-counting the valence overlap, reproduces known limits, or stays stable when the underlying wave-function parameters or Bethe-Salpeter kernel are varied. There are also no quoted uncertainties and no valence-only comparison, so it is difficult to tell how much of the agreement is driven by the correction versus the base model.\n\nThe work stays within standard model-dependent methods for exclusive decays. The citation pattern looks typical for the subfield and does not skip obvious prior light-front or quark-model papers.\n\nThis is for people already working with light-front or constituent-quark descriptions of baryon form factors and semileptonic rates. A reader tracking hyperon data from BESIII might pull the numbers as one more reference point, but the paper does not reorganize anything broader.\n\nIt shows clear engagement with the experimental result and the literature on the method. The calculation is concrete enough that a serious referee could usefully ask for the missing checks on the nonvalence piece. I would send it to peer review.","headline":"The paper computes Lambda semileptonic branching ratios in a light-front quark model with an added effective nonvalence piece and reports agreement with BESIII, but the nonvalence prescription lacks the checks needed to judge its reliability.","tokens_in":2372,"tokens_out":474,"would_cite":false,"duration_ms":29180,"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":"Nonvalence contributions in the light-front quark model produce branching ratios for Lambda semileptonic decays consistent with BESIII data.","keywords":["semileptonic decays","light-front quark model","nonvalence contributions","transition form factors","baryon decays","branching ratios"],"falsifier":"A measurement of the branching ratio for Λ to p electron antineutrino that differs markedly from 8.32×10^{-4} would challenge the accuracy of the nonvalence contribution treatment.","tokens_in":2641,"feed_emoji":"⚛","tokens_out":778,"duration_ms":25779,"temperature":0.7,"pith_summary":"The paper examines the semileptonic decays Lambda to proton with a lepton and antineutrino using the light-front quark model in the Standard Model. Transition form factors are derived by combining valence quark parts with nonvalence contributions treated effectively in the Drell-Yan-West frame from the Bethe-Salpeter formalism. This approach leads to branching ratios of about 8.32 times 10 to the minus 4 for the electron mode and 1.31 times 10 to the minus 4 for the muon mode. These values align with the latest experimental results, highlighting the importance of nonvalence effects in baryon decays.","feed_headline":"Nonvalence terms align Lambda semileptonic rates with experiment","feed_subtitle":"Light-front calculations with these terms give branching ratios of 8.32×10^{-4} and 1.31×10^{-4} matching BESIII data.","key_machinery":"Effective treatment of nonvalence contributions alongside valence ones in the Drell-Yan-West frame using the Bethe-Salpeter formalism to determine the transition form factors in the light-front quark model.","core_discovery":"We investigate the exclusive semileptonic decays of Λ → p ℓ− ν̄ℓ (ℓ=e,μ) within the Standard Model using the light-front quark model. The transition form factor behaviors of Λ → p are obtained from the effective treatment of nonvalence contributions in addition to the valence ones in the Drell-Yan-West frame due to the Bethe-Salpeter formalism. Based on these form factors, we obtain that the branching ratios of Λ→p e− ν̄e and Λ→p μ− ν̄μ, including nonvalence contributions, are around 8.32×10^{-4} and 1.31×10^{-4}, which are consistent with the latest measurements from the BESIII Collaboration, respectively. Our results indicate that nonvalence contributions can play a non-negligible role in","pith_inferences":["Nonvalence contributions could similarly affect predictions for other hyperon semileptonic decays in light-front models.","Refinements to the Bethe-Salpeter treatment might allow extension to decays involving heavier quarks.","High-precision form factor measurements could help separate valence and nonvalence effects experimentally."],"forward_implications":["The branching ratio for the electron decay mode is approximately 8.32×10^{-4}","The branching ratio for the muon decay mode is approximately 1.31×10^{-4}","Nonvalence contributions play a non-negligible role in semileptonic baryon decays","The calculated values are consistent with BESIII measurements"],"fun_headline_variants":["Nonvalence terms key for light-front Lambda semileptonic decays","Light-front model matches BESIII with nonvalence Lambda decay terms","Nonvalence contributions align Lambda rates in light-front quark model","Semileptonic Lambda decays in light-front include nonvalence effects"],"cache_read_input_tokens":2112,"weakest_assumption_plain":"The effective treatment of nonvalence contributions in addition to the valence ones in the Drell-Yan-West frame due to the Bethe-Salpeter formalism accurately determines the Λ to p transition form factors.","fun_headline_variants_meta":{"raw":{"variants":["Nonvalence terms key for light-front Lambda semileptonic decays","Light-front model matches BESIII with nonvalence Lambda decay terms","Nonvalence contributions align Lambda rates in light-front quark model","Semileptonic Lambda decays in light-front include nonvalence effects"]},"model":"grok-4.3","cost_usd":0.006022,"raw_usage":{"total_tokens":2888,"prompt_tokens":743,"num_sources_used":0,"completion_tokens":70,"cost_in_usd_ticks":60224500,"prompt_tokens_details":{"text_tokens":743,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":2075,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":743,"tokens_out":70,"duration_ms":18237,"temperature":1.0,"reasoning_tokens":2075,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-06-28T14:04:01.976338+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"A measurement of the branching ratio for Λ to p electron antineutrino that differs markedly from 8.32×10^{-4} would challenge the accuracy of the nonvalence contribution treatment.","supporting_citations":[],"review_version":1}