{"id":"b8ccf87d-0fad-43b6-b3e0-6b490afae749","arxiv_id":"2412.04572","paper_version":1,"verdict":"ACCEPT","confidence":"MODERATE","novelty_score":5.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":0,"one_line_summary":"Updated LHC and LEP constraints on charged Higgses show that H+ to A W and H+ to H W decay channels are complementary to fermionic channels and extend the search reach in the Type-L 2HDM.","lead":"This paper maps where the LHC and LEP have already ruled out charged Higgs bosons in the four main types of two-Higgs-doublet models, including new decay routes into a W boson plus a neutral Higgs. It shows these 'exotic' decay channels fill gaps left by the usual fermionic searches, especially for heavy charged Higgses in the lepton-specific model.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"Heavy-H± AW reach and the combined exclusion rest on recasting the CMS H±→HW→Wττ search (mH=200 GeV) as H±→AW and extrapolating it to ΔmA=300; if that recast is invalid, the Type-L extension claim is unsupported.","rationale":"The paper is a standard recasting study with named codes (Prospino, 2HDMC, HiggsBounds, SuperIso), and I did not find circular derivations or fitted data; the framework is standard and the qualitative statement that H±→AW opens and dominates for large splittings is grounded in 2HDM couplings (Eqs. 2.5-2.6). The reader's concern about benchmark-mass extrapolation is the right one. I sharpen it: for heavy H±, the only public search is CMS [56], which is for H±→HW with mH=200, not H±→AW, and the paper's mH±=mH assumption closes HW. The brown AW contours in Fig. 4 and the Type-L extension claim therefore depend on a channel-identity and mass-splitting recast that is not documented. If the recast is wrong, the central quantitative claims (Type-L tanβ extension; 'almost entire region' excluded) weaken even though the general complementarity idea survives. This is a testable, non-ad-hominem concern; I recommend acceptance conditional on a validation of that recast, rather than acceptance as-is.","tokens_in":21353,"tokens_out":7879,"duration_ms":80087,"concrete_test":"Re-evaluate the Type-L heavy-H± contour in Fig. 4 using the CMS [56] limit only at mA=200 GeV (i.e. at mH±=500 GeV for ΔmA=300), and generate the remainder of the contour from a full MadGraph5_aMC@NLO + Pythia8 + Delphes simulation of pp→tbH±, H±→AW, A→ττ with ΔmA=300 and the same event selection/final state as [56]. If the resulting brown region is much smaller or absent, the abstract's heavy-H± claim and the combined exclusion statement must be qualified.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"Central claim: for heavy H±, H±→AW/HW extends tanβ reach beyond H±→tb in Type-L, and combining all searches excludes mH± up to ~700 GeV and mA~600 GeV at low tanβ. This requires the experimental exotic-channel limits to be meaningful at the mass points plotted. Section 3/Tab. 3 shows the only heavy exotic search is CMS [56]: H±→HW→Wττ with mH=200 GeV; the only light AW searches are CMS with mH±=mA+85 GeV and ATLAS at mH±=120/140/160 GeV. Section 4.2.1 nonetheless draws a brown H±→AW exclusion in Fig. 4 for ΔmA=300 GeV, where mA=mH±−300. The paper itself notes limits for ΔmA≠85 are only available at mA=200 GeV [56] for mH±>mt, so Fig. 4's brown curve is not backed by a measured limit except near mH±=500 GeV. Moreover, because the analysis imposes mH±=mH, H±→HW is closed; [56] is a HW search, so the figure requires reinterpreting it as AW. A→ττ and H→ττ branching ratios and total widths are not identical at m=200 GeV, and W+A versus W+H spin correlations can alter acceptance. The Type-L tanβ-extension claim and the combined 'almost entire region' statement are exactly the parts of the abstract that depend on this recast.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"This paper interprets public LHC and LEP searches, together with flavor constraints, to map the allowed parameter space of the four 2HDM types. It considers conventional charged-Higgs decays (τν, cs, cb, tb) and the exotic decays H±→AW/HW, using Prospino, 2HDMC, HiggsBounds and SuperIso. It studies degenerate and non-degenerate spectra, with mH±=mH to satisfy electroweak precision constraints, and presents exclusions in the mH±–tanβ, mH±–mA, and mH±–ΔmA planes. The headline results are complementarity of the AW/HW channels for mH±<mt, an extended tanβ reach in the Type-L model for heavy H±, and a combined neutral-plus-charged exclusion up to mH±≈700 GeV and mA≈600 GeV at low tanβ.","tokens_in":21644,"tokens_out":7882,"duration_ms":77216,"significance":"If the heavy-H± exotic recast is valid, the paper makes a useful and falsifiable statement: the H±→AW channel is not redundant and should be included in future LHC search programs, especially in the lepton-specific 2HDM. The analysis is broad, uses standard public tools, and the authors are transparent about the fixed benchmark masses in the CMS/ATLAS exotic searches. The main result is, however, conditional on an extrapolation of the CMS H±→HW search to H±→AW and to mass splittings beyond the measured benchmark, so the significance of the Type-L extension claim is not yet established.","major_comments":[{"comment":"The heavy-H± exotic exclusion in Fig. 4 is based on reinterpreting the CMS H±→WH→Wττ search with mH=200 GeV [56] as an H±→AW limit. This is not a direct reinterpretation: throughout §4.2 the paper imposes mH±=mH, which kinematically closes H±→HW, so the searched process is not the model process; replacing H by A changes the spin state of the ττ system and the relevant branching ratios (e.g., H→hh is absent for A). The paper itself notes (text after Fig. 4) that limits for ΔmA≠85 GeV are only available at mA=200 GeV, but it then draws a smooth brown exclusion over the whole ΔmA=300 plane. Because the abstract's heavy-H± Type-L claim rests on this contour, the authors should either validate the acceptance transfer with a parton-level recast or clearly mark the contour as approximate and soften the corresponding claim.","section":"§4.2.1, Fig. 4, Table 3"},{"comment":"The AW limits are measured only at discrete benchmarks: CMS [54] for mH±=mA+85 GeV, ATLAS [55] for mH±=120/140/160 GeV, and CMS [56] for mA=200 GeV. In Fig. 4 with ΔmA=300 GeV, only mH±=500 GeV corresponds to the mA=200 GeV benchmark; for neighboring points the signal acceptance, especially for the boosted ττ and W selections, is not known. The paper applies the benchmark σ×BR upper limits without an acceptance correction, so the extent of the brown region in Fig. 4 and the statement that the reach of H±→AW slightly increases with larger ΔmA are not supported by data. A conservative treatment would restrict the AW exclusion to the measured mass points, or the authors should provide a model of the mass dependence.","section":"§4.2.1, Fig. 4"}],"minor_comments":[{"comment":"Table 3 labels the first column 'mass channel'; this should be 'mass region / channel', and the final states searched (e.g., Wμμ for the light searches) should be stated in the table or caption for clarity.","section":"§3, Table 3"},{"comment":"The captions say 'Gray area indicates the nonphysical regions with negative values of mA' but the gray area actually begins when mA becomes negative; for ΔmA=85 GeV this means mH±<85 GeV, which is worth stating explicitly.","section":"§4.2.1, captions of Fig. 3 and Fig. 4"},{"comment":"The text says 'The top-left half of the plane is not physical since it corresponds to mA<0', but in the ΔmA vs mH± plane the nonphysical region is the upper-left triangle; the wording should be adjusted to avoid ambiguity (the same applies to Fig. 8).","section":"§4.2.3, Fig. 7"},{"comment":"Reference [74] is formatted incompletely ('Symmetry 16 (2024) no.7, 917 doi:...'); it should include the full author list or standard journal formatting. Several other references (e.g., [29], [39], [46], [50], [51], [55]) lack arXiv identifiers or journal information.","section":"References"},{"comment":"The introductory statement that exotic searches have been performed at '7 TeV, 8 TeV and 13 TeV' is not reflected in Table 3, which lists only 13 TeV searches; please align the text with the table.","section":"§1"}],"recommendation":"major_revision","confidential_remarks":"The substantive issue is the reinterpretation of the CMS H±→WH search as an H±→AW limit and its extrapolation away from the mA=200 GeV benchmark. This is load-bearing for the heavy-H± Type-L claim and for part of the combined exclusion. The rest of the analysis uses standard tools and is presented carefully. If the authors can validate the acceptance transfer or appropriately qualify the affected contours, the paper would be publishable; without that, the main new claim is currently not supported."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Quick take: this is a clean, genuinely useful recast of existing LHC/LEP/flavor constraints onto the four 2HDM types, with the exotic H±→AW/HW modes added and combined with neutral-scalar searches. The stressed soft spot is real but not fatal: the heavy Type-L reach shown for ΔmA = 300 builds on an explicit reinterpretation of the CMS H±→HW→Wττ search (fixed mH = 200 GeV) as an AW mode, and the brown contours in Fig. 4 extrapolate that single benchmark in mA. The paper itself says the only heavy exotic limits are at mA = 200, so the extrapolation is disclosed, but the contours are drawn as if measured. Since mH± = mH is assumed, H±→HW is closed; replacing H by A changes the ττ branching ratio slightly and the spin correlations in the τ pair, so acceptance is not identical. The Type-L tanβ-extension sentence in the abstract hangs on exactly this recast, so it should be softened or validated.\n\nEverything else is in good shape. The light-H± AW limits are applied at their measured points (ΔmA = 85; mH± = 120/140/160), the combined exclusion plots rest largely on the neutral A/H searches, which are properly taken from the literature, and the flavor treatment with SuperIso is standard. No sign of circular fitting or invented entities. The references include the authors' own earlier work on exotic and neutral-scalar searches, but that work is background, and the constraints come from external measurements.\n\nThe paper is a status update, not a new technique; it will be cited by people mapping 2HDM exclusions, especially for the light-mass AW reach and the combined maps. I would send it to a referee. The revision should mark the heavy-AW contours as approximate reinterpretations, check the A-vs-H ττ branching and acceptance, and adjust the abstract.","headline":"Useful status recast of 2HDM charged Higgs searches; the heavy-mass Type-L AW reach rests on an extrapolated reinterpretation of the CMS HW search and should be flagged as such.","tokens_in":22197,"tokens_out":6368,"would_cite":true,"duration_ms":112715,"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":"The paper argues that charged-Higgs decays to a W plus a neutral Higgs are not redundant: they are complementary to the standard fermionic channels and extend the LHC's reach in the lepton-specific two-Higgs-doublet model.","keywords":["charged Higgs boson","two Higgs doublet model","H± → AW decay","H± → HW decay","LHC searches","lepton-specific 2HDM","flavor constraints","tan β reach"],"falsifier":"Perform a detector-level simulation of the $H^\\pm\\to AW$ signal at a non-benchmark point, for instance $m_{H^\\pm}\\approx500$ GeV with $m_A\\approx200$ GeV or $\\Delta m_A\\approx300$ GeV, using the same event selection as the published searches; if the reconstructed acceptance is materially lower than at the benchmark masses, the claimed excluded regions in the $m_{H^\\pm}$ vs. $\\tan\\beta$ and $m_{H^\\pm}$ vs. $\\Delta m_A$ planes would shrink.","tokens_in":21117,"feed_emoji":"⚛️","tokens_out":10344,"duration_ms":92228,"temperature":0.7,"pith_summary":"Charged Higgs bosons in the four types of two-Higgs-doublet models are usually searched for through decays to fermions: $H^\\pm \\to \\tau\\nu,\\ cs,\\ cb,\\ tb$. This paper asks whether the less-studied decays to a $W$ plus a neutral Higgs, $H^\\pm \\to AW$ and $H^\\pm \\to HW$, deserve the same experimental attention. It answers yes: once these channels are kinematically open they dominate the charged-Higgs decay width, and the current limits on them fill in gaps left by the fermionic channels for $m_{H^\\pm}$ below the top-quark mass. For heavy charged Higgses in the lepton-specific (Type-L) 2HDM, $H^\\pm \\to AW$ reaches $\\tan\\beta$ values that $H^\\pm \\to tb$ cannot cover. Combining all charged and neutral Higgs searches, the paper finds that almost the entire low-$\\tan\\beta$ region with $m_{H^\\pm}$ up to about 700 GeV and $m_A$ up to about 600 GeV is already excluded.","feed_headline":"Exotic charged-Higgs decays fill LHC search gaps","feed_subtitle":"The H±→AW/HW channels reach parameter space the standard tb search misses, excluding masses up to ~700 GeV.","key_machinery":"The machinery is the two-Higgs-doublet model itself, with its four fermion-coupling types (Type-I, Type-II, Type-L, Type-F), plus the exotic three-point coupling $g_{H^\\pm AW}=(g/2)(p_A-p_{H^\\pm})_\\mu$ that lets $H^\\pm\\to AW$ dominate once it is kinematically open. The paper turns published $\\sigma\\times$BR upper limits into exclusion contours in the ($m_{H^\\pm}$, $m_A$, $\\tan\\beta$) plane using NLO production cross sections, a 2HDM branching-fraction calculator, and LEP limits, under the electroweak-precision-motivated assumption $m_{H^\\pm}=m_H$ so that $H^\\pm\\to HW$ is closed and the results are independent of $c_{\\beta-\\alpha}$.","core_discovery":"The central claim is that the exotic decays $H^\\pm \\to AW/HW$ are not an afterthought but a complementary main channel for charged-Higgs searches. Because the $H^\\pm AW$ coupling is not suppressed by $\\tan\\beta$ or by the alignment limit, the decay $H^\\pm \\to AW$ quickly dominates once $m_{H^\\pm}>m_A+m_W$, and $H^\\pm \\to HW$ plays the same role when the mass relation $m_{H^\\pm}=m_H$ is relaxed. Using published $\\sigma\\times$BR limits, the paper shows that for $m_{H^\\pm}<m_t$ these exotic channels are complementary to the $\\tau\\nu$, $cs$, and $cb$ searches, and for heavy $m_{H^\\pm}$ in the Type-L 2HDM they extend the excluded range of $\\tan\\beta$ beyond what $H^\\pm\\to tb$ achieves. With neutral-Higgs search constraints included, almost the entire region with $m_{H^\\pm}\\lesssim700$ GeV and $m_A\\lesssim600$ GeV is excluded at low $\\tan\\beta$.","pith_inferences":["If the benchmark-limit rescaling holds, existing LHC data may already be sensitive to additional 2HDM regions that no dedicated search has targeted; a full-simulation reinterpretation could sharpen these bounds without new data.","The same complementarity should appear in other models with extended Higgs sectors, such as supersymmetric ones, wherever a charged Higgs can decay to a $W$ and a lighter neutral Higgs; the Type-L case identifies where such a search would pay off.","The continuum $t\\bar{t}b\\bar{b}$ measurements, which the paper flags but does not recast, could constrain the large-width region $\\Gamma/m_{H^\\pm}>0.1$ where resonant searches break down.","Extending the $H^\\pm\\to AW$ search to scan $m_A$ as well as $m_{H^\\pm}$, rather than fixing $m_A=200$ GeV, is the paper's own suggested next step and would likely enlarge the Type-L exclusion."],"forward_implications":["Dedicated LHC searches for $H^\\pm\\to AW/HW$ should be extended over the full $m_{H^\\pm}$ vs. $m_A$ plane, since the current fixed-mass-point searches leave much of the kinematically open region untested.","In the Type-L 2HDM, $H^\\pm\\to AW$ is the best heavy-charged-Higgs channel for $\\tan\\beta$ between about 1 and 5, surpassing $H^\\pm\\to tb$; analyses that only use the $tb$ channel underestimate the excluded parameter space.","At low $\\tan\\beta$, the combination of charged and neutral Higgs searches excludes almost the whole region with $m_{H^\\pm}$ up to about 700 GeV and $m_A$ up to about 600 GeV, leaving only a narrow gap near $m_{H^\\pm}\\sim m_t$.","When $H^\\pm\\to AW$ opens, the fermionic branching fractions are redistributed, so exclusion limits derived from $\\tau\\nu$, $cs$, $cb$, or $tb$ alone do not carry over to non-degenerate mass spectra."],"supporting_citations":[{"why":"Defines the 2HDM potential, the four fermion-coupling types, and the couplings used to compute all decay widths.","marker":"[4]"},{"why":"Provides the previous comprehensive status of the charged Higgs in 2HDM that this work updates with the exotic channels.","marker":"[5]"},{"why":"Proposed the $H^\\pm\\to AW/HW$ search channel and argued for its complementarity, which motivates the paper's central question.","marker":"[9]"},{"why":"Supplies the neutral-scalar search constraints that are folded in to produce the combined exclusion in the $m_A$ vs. $m_{H^\\pm}$ plane.","marker":"[53]"},{"why":"Supplies the $\\Delta m_A=85$ GeV $\\sigma\\times$BR limit that drives the light-charged-Higgs exotic reach.","marker":"[54]"},{"why":"Provides the $m_{H^\\pm}=120,140,160$ GeV $\\sigma\\times$BR limits for light $H^\\pm\\to AW\\to W\\mu\\mu$.","marker":"[55]"},{"why":"Supplies the only heavy-charged-Higgs $H^\\pm\\to HW\\to W\\tau\\tau$ limit at $m_A=200$ GeV, which extends the $\\tan\\beta$ reach in Type-L.","marker":"[56]"},{"why":"Supplies the NLO charged-Higgs production cross sections used in every reach calculation.","marker":"[80]"},{"why":"Computes the 2HDM branching fractions that convert the quoted $\\sigma\\times$BR limits into exclusion contours.","marker":"[82]"},{"why":"Provides the NNLO $B\\to X_s\\gamma$ prediction that underlies the flavor constraints dominating Type-II and Type-F.","marker":"[72]"}],"fun_headline_variants":["Exotic H± decays fill LHC search gaps","H±→AW/HW channels expand 2HDM exclusion","Exotic H± decays complement standard searches","Charged Higgs search gains from AW/HW decays","Complementary H± decays boost LHC exclusion"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The results rest on applying experimental $H^\\pm\\to AW$ limits measured at only a few benchmark mass points ($m_{H^\\pm}=m_A+85$ GeV; $m_{H^\\pm}=120,140,160$ GeV; $m_A=200$ GeV) to very different mass splittings such as $\\Delta m_A=300$ GeV, with simple acceptance scaling rather than a full simulation at each point.","fun_headline_variants_meta":{"raw":{"variants":["Exotic H± decays fill LHC search gaps","H±→AW/HW channels expand 2HDM exclusion","Exotic H± decays complement standard searches","Charged Higgs search gains from AW/HW decays","Complementary H± decays boost LHC exclusion"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000853,"raw_usage":{"total_tokens":3724,"prompt_tokens":982,"completion_tokens":2742,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":598,"completion_tokens_details":{"reasoning_tokens":2665}},"tokens_in":598,"tokens_out":2742,"duration_ms":19259,"temperature":1.0,"reasoning_tokens":2665,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-11T21:23:39.580206+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Perform a detector-level simulation of the $H^\\pm\\to AW$ signal at a non-benchmark point, for instance $m_{H^\\pm}\\approx500$ GeV with $m_A\\approx200$ GeV or $\\Delta m_A\\approx300$ GeV, using the same event selection as the published searches; if the reconstructed acceptance is materially lower than at the benchmark masses, the claimed excluded regions in the $m_{H^\\pm}$ vs. $\\tan\\beta$ and $m_{H^\\pm}$ vs. $\\Delta m_A$ planes would shrink.","supporting_citations":[],"review_version":1}