{"id":"b3cc33c1-542c-467b-aa56-cc5765775f63","arxiv_id":"2605.31235","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":6.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":0,"one_line_summary":"First TCT tests of unconventional strip-like pad geometries in RSD/AC-LGAD sensors show strong one-dimensional spatial resolution.","lead":"This paper reports the first lab characterization of new mixed strip-pixel readout pad shapes in resistive AC-coupled silicon detectors using laser-based Transient Current Technique measurements. These designs aim to deliver high one-dimensional position resolution with fewer readout channels for future particle colliders.","discovery_kind":"new_application","skeptic_critique":{"model":"grok-4.3","headline":"TCT laser results on unirradiated prototypes may not translate to MIP performance under collider radiation/rate/noise","rationale":"The load-bearing concern is identical to the reader's weakest_assumption. The paper's scope (first TCT characterization) makes the extrapolation step the least secure link; no internal inconsistency or other technical flaw is identifiable from the given material. Full-text access does not remove the need for radiation and beam validation before collider relevance can be asserted.","tokens_in":1677,"tokens_out":318,"duration_ms":16090,"concrete_test":"Repeat the spatial-resolution scan on the same strip-like RSD sensors after 1e15 neq/cm² irradiation using a ⁹⁰Sr beta source or test-beam MIPs instead of TCT laser; if the extracted 1D resolution degrades by more than a factor of two relative to the unirradiated TCT value, the headline claim weakens.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The central claim rests on TCT measurements demonstrating 'exceptional one-dimensional spatial resolution' that confirms potential for EIC/FCC tracking. This requires that laser-induced charge-sharing signals on fresh sensors accurately predict MIP response after irradiation and at high rates. The work is explicitly a first TCT characterization of novel pad geometries; no irradiated samples, beta-source, or beam-test data are referenced in the abstract or described methods. If the resolution advantage disappears once radiation-induced trapping and increased noise are included, the confirmation of potential does not follow from the presented evidence.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript reports the first TCT characterization of novel mixed strip/pixel readout pad geometries fabricated in the second FBK RSD production run. It claims these designs achieve exceptional one-dimensional spatial resolution while reducing channel count relative to full pixel layouts, thereby confirming their suitability for outer-region tracking in future colliders (EIC, FCC-ee, etc.).","tokens_in":1780,"tokens_out":358,"duration_ms":16841,"significance":"If the reported one-dimensional resolution advantage is reproducible under realistic conditions, the work would be significant for 4D tracker design by offering a practical route to lower channel counts without sacrificing position precision in one coordinate. The experimental approach on unconventional pad shapes is a useful addition to the RSD literature.","major_comments":[{"comment":"Abstract: the claim of 'exceptional one-dimensional spatial resolution' is presented without any numerical values, error bars, or direct comparison to standard strip or pixel RSD geometries, rendering the central experimental conclusion impossible to evaluate quantitatively.","section":"Abstract"},{"comment":"Abstract: the assertion that the TCT results 'confirm the potential' for EIC/FCC tracking systems rests on the untested assumption that laser-induced charge-sharing signals on unirradiated prototypes will translate to MIP response after irradiation, at high rates, and with realistic noise; no irradiated devices, beta-source, or beam-test data are referenced, which is load-bearing for the stated application claim.","section":"Abstract"}],"minor_comments":[{"comment":"The abstract would be strengthened by inclusion of at least one key quantitative result (e.g., resolution value in μm) so that the 'exceptional' descriptor can be assessed without reading the full text.","section":null}],"recommendation":"major_revision","confidential_remarks":null},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for the constructive feedback on our manuscript. We address each major comment below and have revised the abstract to incorporate quantitative details and to moderate the application-oriented claims in line with the scope of the TCT data presented.","responses":[{"response":"We agree that the abstract should provide quantitative context. In the revised manuscript the abstract will be updated to report the measured one-dimensional resolutions (with uncertainties) obtained for the novel geometries and to include explicit comparisons against standard strip and pixel RSD layouts characterized in the same TCT setup and in prior literature. These values are already present in the results section and will now be highlighted in the abstract.","revision_made":"yes","referee_comment":"[Abstract] Abstract: the claim of 'exceptional one-dimensional spatial resolution' is presented without any numerical values, error bars, or direct comparison to standard strip or pixel RSD geometries, rendering the central experimental conclusion impossible to evaluate quantitatively."},{"response":"We accept this criticism. The present study is limited to TCT measurements on unirradiated devices. We will revise the abstract to replace 'confirm the potential' with 'indicate the potential' and will add a sentence noting that translation to MIP response, radiation hardness, and high-rate operation remains to be verified in future beam-test and irradiation campaigns. This change aligns the claim with the data actually shown.","revision_made":"yes","referee_comment":"[Abstract] Abstract: the assertion that the TCT results 'confirm the potential' for EIC/FCC tracking systems rests on the untested assumption that laser-induced charge-sharing signals on unirradiated prototypes will translate to MIP response after irradiation, at high rates, and with realistic noise; no irradiated devices, beta-source, or beam-test data are referenced, which is load-bearing for the stated application claim."}],"tokens_in":1297,"tokens_out":404,"duration_ms":17109,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The paper's core contribution is the first reported TCT characterization of the unconventional mixed pad shapes in the second FBK RSD production. These geometries sit between classic pixels and strips, aiming to deliver one-dimensional spatial resolution while cutting channel count for outer tracker layers at the EIC and similar machines.\n\nWhat stands out is the experimental focus on real fabricated sensors rather than simulation alone. The authors took the new layouts and measured charge-sharing behavior with the transient current technique, which directly tests the resistive AC-LGAD principle in these shapes. That is useful incremental work for the RSD community.\n\nThe soft spot is the gap between the presented data and the stated implications. All results come from laser TCT on fresh, unirradiated prototypes. No irradiated samples, no beta-source or beam-test MIP data, and no rate or noise studies appear in the abstract or described methods. The claim that these measurements confirm potential for future tracking systems therefore depends on an unshown assumption: that the observed one-dimensional resolution will survive radiation-induced trapping, increased leakage, and collider noise levels. If that assumption fails, the practical advantage shrinks.\n\nThe work is aimed at groups already building or testing RSD/AC-LGAD sensors for 4D tracking. A reader already following FBK productions will want the quantitative resolution numbers, error bars, and direct comparisons that the abstract omits. For anyone outside that niche the paper is too preliminary.\n\nIt deserves peer review so the full dataset and analysis can be checked, but the manuscript will need to address the translation from lab laser to collider conditions before the broader claims land.","headline":"First TCT data on mixed strip-pixel RSD pads from the second FBK run, but the collider-readiness claim rests on untested assumptions about laser results translating to MIPs after radiation.","tokens_in":2235,"tokens_out":411,"would_cite":false,"duration_ms":10813,"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":"Novel strip-like readout geometries in resistive AC-coupled silicon detectors achieve exceptional one-dimensional spatial resolution.","keywords":["resistive silicon detectors","AC-LGAD","spatial resolution","strip readout","transient current technique","silicon sensors","particle tracking","readout geometries"],"falsifier":"A measurement of spatial resolution using actual particle beams on irradiated sensors at collider-like rates.","tokens_in":2602,"feed_emoji":"","tokens_out":529,"duration_ms":20384,"temperature":0.7,"pith_summary":"The paper examines new pad shapes in RSD sensors that blend strip and pixel readout features. These shapes target applications needing precise position measurement in only one direction to cut down on the total number of readout channels. Laser-based tests on the prototypes reveal strong spatial resolution along the preferred axis. The results indicate that such mixed geometries can support tracking detectors that combine timing and position information. This approach addresses the practical need for efficient designs in large-scale systems.","feed_headline":"Mixed pad shapes deliver strip-like resolution in RSD sensors","feed_subtitle":"Laser tests show high one-dimensional precision, enabling fewer readout channels for outer tracker regions.","key_machinery":"Unconventional readout pad shapes mixing strip-like and pixel-like geometries, characterized through Transient Current Technique laser illumination.","core_discovery":"The second production of RSD sensors includes sensors with unconventional readout pad shapes that act as a mixture between strip-like and pixel-like readout. Transient Current Technique measurements on these designs demonstrate exceptional one-dimensional spatial resolution, confirming the potential of novel strip-like RSDs for future tracking systems.","pith_inferences":["Adapting the pad shapes for different sensor sizes could extend their use to larger detector areas.","Signal processing algorithms tailored to the mixed shapes may further enhance the effective resolution.","Pairing these sensors with timing electronics could enable full four-dimensional reconstruction in a single layer."],"forward_implications":["The mixed pad shapes reduce the number of readout channels needed for high resolution in one direction.","These geometries maintain good performance in regions farther from the interaction point.","They support the construction of tracking systems that record both position and timing information.","The designs offer a path to scalable sensors without sacrificing one-dimensional precision."],"fun_headline_variants":["Mixed pad shapes in RSD for strip-like resolution","One-D resolution measured in mixed RSD pad designs","Mixed readout geometries tested in RSD sensors","Strip-like readout in mixed pad RSD designs"],"cache_read_input_tokens":2112,"weakest_assumption_plain":"Results from laser tests on prototype sensors will match performance when the detectors face real radiation, particle rates, and electronic noise.","fun_headline_variants_meta":{"raw":{"variants":["Mixed pad shapes in RSD for strip-like resolution","One-D resolution measured in mixed RSD pad designs","Mixed readout geometries tested in RSD sensors","Strip-like readout in mixed pad RSD designs"]},"model":"grok-4.3","cost_usd":0.00774,"raw_usage":{"total_tokens":3518,"prompt_tokens":629,"num_sources_used":0,"completion_tokens":58,"cost_in_usd_ticks":77399500,"prompt_tokens_details":{"text_tokens":629,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":2831,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":629,"tokens_out":58,"duration_ms":19169,"temperature":1.0,"reasoning_tokens":2831,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-06-28T19:57:48.882711+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"A measurement of spatial resolution using actual particle beams on irradiated sensors at collider-like rates.","supporting_citations":[],"review_version":1}