We derive predictions for the hadronic matrix elements of radiative semileptonic decays of beautiful hadrons within Heavy Quark Effective Theory (HQET), relevant for future measurements at Belle II and LHCb. Our study considers Λb → Λc, Λ(*)_c1 and B\u0305 → D(*), D** transitions. The symmetries of HQET highly constrain the number of structure-dependent form factors in all cases. In the soft and sub-leading soft regions, all the form factors are fully determined in terms of non-radiative Isgur-Wise functions and the magnetic dipole moments of the heavy hadrons. The structure of higher order corrections is also briefly discussed.
", "doi": "10.1007/jhep05(2026)097", "issn": "1029-8479", "publisher": "Springer Science and Business Media LLC", "publication": "Journal of High Energy Physics", "publication_date": "2026-05", "series_number": "5", "volume": "2026", "issue": "5", "pages": "97" }, { "id": "authors:xqy5k-xk744", "collection": "authors", "collection_id": "xqy5k-xk744", "cite_using_url": "https://authors.library.caltech.edu/records/xqy5k-xk744", "type": "article", "title": "Off-shell vertices in heavy particle effective theories and B \u2192 D\u03c0\u2113\u03bd", "author": [ { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Plestid", "given_name": "Ryan", "orcid": "0000-0003-0779-7289", "clpid": "Plestid-Ryan" } ], "abstract": "We study the modifications to decay amplitudes in heavy to heavy semileptonic decays with multiple hadrons in the final state due to intermediate heavy hadrons being off-shell or having a finite width. Combining Heavy Hadron Chiral Perturbation Theory (HHχPT) with a BCFW on-shell factorization formula, we show that these effects induce (1/M) corrections to the standard results computed in the narrow-width approximation and therefore are important in extracting form factors from data. A combination of perturbative unitarity, analyticity, and reparameterization invariance fully determine these corrections in terms of known Isgur-Wise functions without the need to introduce new form factors. In doing so, we develop a novel technique to compute the boundary term at complex infinity in the BCFW formula for theories with derivatively coupled scalars. While we have used the B → Dπ\u2113ν decay as an example, these techniques can generally be applied to effective field theories with (multiple) distinct reference vectors.
", "doi": "10.1007/jhep06(2025)190", "issn": "1029-8479", "publisher": "Springer Science and Business Media LLC", "publication": "Journal of High Energy Physics", "publication_date": "2025-06", "series_number": "6", "volume": "2025", "issue": "6", "pages": "190" }, { "id": "authors:ekd1e-ydg32", "collection": "authors", "collection_id": "ekd1e-ydg32", "cite_using_url": "https://authors.library.caltech.edu/records/ekd1e-ydg32", "type": "article", "title": "Appraising constrained second-order power corrections in HQET with \u039bb\u2192\u039bcl\u03bd", "author": [ { "family_name": "Bernlochner", "given_name": "Florian U.", "orcid": "0000-0001-8153-2719" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Robinson", "given_name": "Dean J.", "orcid": "0000-0003-0057-1703" } ], "abstract": "We derive the \u039bb\u2192\u039bc form factors for the Standard Model and beyond at second order in heavy quark effective theory, applying the recently proposed residual chiral expansion to reduce the set of unknown subsubleading hadronic functions to a single, highly constrained function, that is fully determined by hadron mass parameters at zero recoil. We fit a form factor parametrization based on these results to all available lattice QCD predictions and experimental data. We find that the constrained and predictive structure of the form factors under the residual chiral expansion is in excellent agreement with lattice QCD predictions and experimental data, as well as prior heavy-quark-effective-theory-based fits.\n \n \n \n \n Published by the American Physical Society\n 2025", "doi": "10.1103/physrevd.111.036001", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2025-02-01", "series_number": "3", "volume": "111", "issue": "3", "pages": "036001" }, { "id": "authors:my4pz-20v43", "collection": "authors", "collection_id": "my4pz-20v43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230612-735489000.31", "type": "article", "title": "Exploring the \u03c4 polarization in B \u2192 X\u03c4\u03bd along different axes", "author": [ { "family_name": "Bernlochner", "given_name": "Florian U.", "orcid": "0000-0001-8153-2719", "clpid": "Bernlochner-Florian-U" }, { "family_name": "Ligeti", "given_name": "Zoltan", "orcid": "0000-0002-4830-5773", "clpid": "Ligeti-Zoltan" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Robinson", "given_name": "Dean J.", "orcid": "0000-0003-0057-1703", "clpid": "Robinson-Dean-J" } ], "abstract": "The \u03c4 polarization in semileptonic B decays provides probes of new physics complementary to decay rate distributions of the three-body final state. Prior calculations for inclusive decays used a definition for the polarization axis that is different from the choice used in calculations (and the only measurement) for exclusive channels. To compare inclusive and exclusive predictions, we calculate the \u03c4 polarization in inclusive B \u2192 X\u03c4\u03bd using the same choice as in the exclusive decays, and construct a sum rule relating the inclusive \u03c4 polarization to a weighted sum of exclusive decay polarizations. We use this relation, experimental data, and theoretical predictions for the decays to the lightest charm or up-type hadrons to make predictions for excited channels.", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2023-05-01", "series_number": "9", "volume": "107", "issue": "9", "pages": "Art. No. 096008" }, { "id": "authors:329dh-6hd34", "collection": "authors", "collection_id": "329dh-6hd34", "cite_using_url": "https://authors.library.caltech.edu/records/329dh-6hd34", "type": "article", "title": "Exploring the \u03c4 polarization in B\u2192X\u03c4\u03bd\u0304 along different axes", "author": [ { "family_name": "Bernlochner", "given_name": "Florian U.", "orcid": "0000-0001-8153-2719" }, { "family_name": "Ligeti", "given_name": "Zoltan", "orcid": "0000-0002-4830-5773" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Robinson", "given_name": "Dean J." } ], "abstract": "The \ud835\udf0f polarization in semileptonic \ud835\udc35 decays provides probes of new physics complementary to decay rate distributions of the three-body final state. Prior calculations for inclusive decays used a definition for the polarization axis that is different from the choice used in calculations (and the only measurement) for exclusive channels. To compare inclusive and exclusive predictions, we calculate the \ud835\udf0f polarization in inclusive \ud835\udc35→\ud835\udc4b\u2062\ud835\udf0f\u2062¯\ud835\udf08 using the same choice as in the exclusive decays, and construct a sum rule relating the inclusive \ud835\udf0f polarization to a weighted sum of exclusive decay polarizations. We use this relation, experimental data, and theoretical predictions for the decays to the lightest charm or up-type hadrons to make predictions for excited channels.
", "doi": "10.1103/PhysRevD.107.096008", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2023-05-01", "series_number": "9", "volume": "107", "issue": "9", "pages": "096008" }, { "id": "authors:tgnd1-qs079", "collection": "authors", "collection_id": "tgnd1-qs079", "cite_using_url": "https://authors.library.caltech.edu/records/tgnd1-qs079", "type": "article", "title": "Interpreting LHCb's \u039bb\u2192\u039bc\u03c4\u03bd\u0304 measurement and puzzles in semileptonic \u039bb decays", "author": [ { "family_name": "Bernlochner", "given_name": "Florian U." }, { "family_name": "Ligeti", "given_name": "Zoltan", "orcid": "0000-0002-4830-5773" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Robinson", "given_name": "Dean J." } ], "abstract": "Normalizing the recent LHCb measurement of Λ\ud835\udc4f→Λ\ud835\udc50\u2062\ud835\udf0f\u2062¯\ud835\udf08 to the standard model (SM) prediction for the Λ\ud835\udc4f→Λ\ud835\udc50\u2062\ud835\udf07\u2062¯\ud835\udf08 rate, instead of a LEP measurement, provides a more consistent comparison with the SM prediction for the lepton flavor universality ratio \ud835\udc45\u2061(Λ\ud835\udc50). This modestly increases \ud835\udc45\u2061(Λ\ud835\udc50) compared to the quoted LHCb result, such that it no longer hints at a suppression compared to the SM, which would be hard to accommodate in new physics scenarios that enhance \ud835\udc45\u2061(\ud835\udc37(*)). We point out that the fraction of excited states in inclusive semileptonic Λ\ud835\udc4f decay may be significantly greater than the corresponding fraction in \ud835\udc35 decays. Possible implications are speculated upon.
", "doi": "10.1103/physrevd.107.l011502", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2023-01-11", "series_number": "1", "volume": "107", "issue": "1", "pages": "L011502" }, { "id": "authors:ee2q2-52982", "collection": "authors", "collection_id": "ee2q2-52982", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230103-817548100.25", "type": "article", "title": "Constrained second-order power corrections in HQET: R(D\u207d*\u207e), |V_(cb)|, and new physics", "author": [ { "family_name": "Bernlochner", "given_name": "Florian U.", "orcid": "0000-0001-8153-2719", "clpid": "Bernlochner-Florian-U" }, { "family_name": "Ligeti", "given_name": "Zoltan", "orcid": "0000-0002-4830-5773", "clpid": "Ligeti-Zoltan" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Prim", "given_name": "Markus T.", "orcid": "0000-0002-1407-7450", "clpid": "Prim-Markus-T" }, { "family_name": "Robinson", "given_name": "Dean J.", "orcid": "0000-0003-0057-1703", "clpid": "Robinson-Dean-J" }, { "family_name": "Xiong", "given_name": "Chenglu", "orcid": "0000-0002-9573-0748", "clpid": "Xiong-Chenglu" } ], "abstract": "We postulate a supplemental power counting within the heavy quark effective theory (HQET) that results in a small, highly constrained set of second-order power corrections, compared to the standard approach. We determine all B\u0305 \u2192 D\u207d*\u207e form factors, both within and beyond the standard model to O(\u03b1\u209b/m_(c,b), 1/m\u00b2_(c,b)), under truncation by this power counting. We show that the second-order power corrections to the zero-recoil normalization of the B\u0305 \u2192 D\u207d*\u207el\u03bd matrix elements (l = e, \u03bc, \u03c4) are fully determined by hadron mass parameters and are in good agreement with lattice QCD (LQCD) predictions. We develop a parametrization of these form factors under the postulated truncation, that achieves excellent fits to the available LQCD predictions and experimental data, and we provide precise updated predictions for the B\u0305 \u2192 D\u207d*\u207e\u03c4\u03bd\u0305 decay rates, lepton flavor universality violation ratios R(D\u207d*\u207e), and the Cabibbo-Kobayashi-Maskawa matrix element |V_(cb)|. We point out some apparent errors in prior literature concerning the O(1/m_(c)m_(b)) corrections and note a tension between commonly used simplified dispersive bounds and current data.", "doi": "10.1103/physrevd.106.096015", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2022-11-01", "series_number": "9", "volume": "106", "issue": "9", "pages": "Art. No. 096015" }, { "id": "authors:nerfq-fmr76", "collection": "authors", "collection_id": "nerfq-fmr76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211029-211331383", "type": "article", "title": "Radiative semileptonic B\u0305 decays", "author": [ { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Trickle", "given_name": "Tanner", "orcid": "0000-0003-1371-4988", "clpid": "Trickle-Tanner" }, { "family_name": "Wise", "given_name": "Mark B.", "orcid": "0000-0002-9125-801X", "clpid": "Wise-M-B" } ], "abstract": "We consider the form factors for the radiative semileptonic decays B\u0305(v) \u2192 D(*)(v\u2032)\u2113\u03bd\u0305_\u2113\u03b3 in the kinematic region where the photon momentum, k, is small enough that heavy quark symmetry (HQS) can be applied without the radiated photon changing the heavy quark velocity (i.e., v(\u2032) \u2219 k < m(b,c)). We find that HQS is remarkably powerful, leaving only four new undetermined form factors at leading order in 1/m(b,c). In addition, one of them is fixed in terms of the leading order Isgur-Wise function in the kinematic region, v(\u2032) \u2219 k < \u039b_(QCD).", "doi": "10.1007/JHEP02(2022)043", "issn": "1126-6708", "publisher": "Springer", "publication": "Journal of High Energy Physics", "publication_date": "2022-02", "series_number": "2", "volume": "2022", "issue": "2", "pages": "Art. No. 43" }, { "id": "authors:vnjgx-rzq56", "collection": "authors", "collection_id": "vnjgx-rzq56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220207-90458000", "type": "article", "title": "Form factor counting and HQET matching for new physics in \n \u039b_b \u2192 \u039b_c*l\u03bd", "author": [ { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Robinson", "given_name": "Dean J.", "clpid": "Robinson-Dean-J" } ], "abstract": "We calculate the \u039b_b \u2192 \u039b\u2217_c(2595)l\u03bd and \u039b_b \u2192 \u039b\u2217_c(2625)l\u03bd form factors and decay rates for all possible b\u2192cl\u03bd\u0305 four-Fermi interactions in and beyond the Standard Model (SM), including nonzero charged lepton masses and terms up to order O(\u03b1_s,1/m_(c,b)) in the heavy quark effective theory (HQET). We point out a subtlety involving the overcompleteness of the representation of the spin-parity 1/2\u207a \u2192 3/2\u207b antisymmetric tensor form factors, relevant also to other higher excited-state transitions, and present a general method for the counting of the physical form factors for any hadronic transition matrix element and their matching onto HQET. We perform a preliminary fit of a simple HQET-based parametrization of the \u039b_b \u2192 \u039b\u2217_c form factors at O(\u03b1_s,1/m_(c,b)) to an existing quark model, providing preliminary predictions for the lepton universality ratios R(\u039b\u2217_c) beyond the SM. Finally, we examine the putative incompatibility of recent lattice QCD results with expectations from the heavy-quark expansion and available experimental data.", "doi": "10.1103/physrevd.105.016027", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2022-01-01", "series_number": "1", "volume": "105", "issue": "1", "pages": "Art. No. 016027" }, { "id": "authors:9dc6a-83550", "collection": "authors", "collection_id": "9dc6a-83550", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201224-134252183", "type": "article", "title": "Expression of interest for the CODEX-b detector", "author": [ { "family_name": "Aielli", "given_name": "Giulio", "orcid": "0000-0002-0573-8114", "clpid": "Aielli-Giulio" }, { "family_name": "Ben-Haim", "given_name": "Eli", "clpid": "Ben-Haim-Eli" }, { "family_name": "Cardarelli", "given_name": "Roberto", "clpid": "Cardarelli-Roberto" }, { "family_name": "Charles", "given_name": "Matthew John", "clpid": "Charles-Matthew-John" }, { "family_name": "Cid Vidal", "given_name": "Xabier", "orcid": "0000-0002-0468-541X", "clpid": "Cid-Vidal-Xabier" }, { "family_name": "Coco", "given_name": "Victor", "orcid": "0000-0002-5310-6808", "clpid": "Coco-Victor" }, { "family_name": "Dey", "given_name": "Biplab", "orcid": "0000-0002-4563-5806", "clpid": "Dey-Biplab" }, { "family_name": "Dumps", "given_name": "Raphael", "clpid": "Dumps-Raphael" }, { "family_name": "Evans", "given_name": "Jared A.", "orcid": "0000-0001-9871-6557", "clpid": "Evans-Jared-A" }, { "family_name": "Gibbons", "given_name": "George", "clpid": "Gibbons-George" }, { "family_name": "Le Dortz", "given_name": "Olivier", "clpid": "Le-Dortz-Olivier" }, { "family_name": "Gligorov", "given_name": "Vladimir V.", "orcid": "0000-0002-8189-8267", "clpid": "Gligorov-Vladimir-V" }, { "family_name": "Ilten", "given_name": "Philip", "orcid": "0000-0001-5534-1732", "clpid": "Ilten-Philip" }, { "family_name": "Knapen", "given_name": "Simon", "orcid": "0000-0002-6733-9231", "clpid": "Knapen-Simon" }, { "family_name": "Lee", "given_name": "Jongho", "orcid": "0000-0003-0398-4220", "clpid": "Lee-Jongho" }, { "family_name": "L\u00f3pez Soli\u00f1o", "given_name": "Saul", "clpid": "L\u00f3pez-Soli\u00f1o-Saul" }, { "family_name": "Nachman", "given_name": "Benjamin", "orcid": "0000-0003-1024-0932", "clpid": "Nachman-Benjamin" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Polci", "given_name": "Francesco", "orcid": "0000-0001-8058-0436", "clpid": "Polci-Francesco" }, { "family_name": "Quessard", "given_name": "Robin", "clpid": "Quessard-Robin" }, { "family_name": "Ramani", "given_name": "Harikrishnan", "orcid": "0000-0003-3804-8598", "clpid": "Ramani-Harikrishnan" }, { "family_name": "Robinson", "given_name": "Dean J.", "clpid": "Robinson-Dean-J" }, { "family_name": "Schindler", "given_name": "Heinrich", "clpid": "Schindler-Heinrich" }, { "family_name": "Sokoloff", "given_name": "Michael D.", "clpid": "Sokoloff-Michael-D" }, { "family_name": "Swallow", "given_name": "Paul", "clpid": "Swallow-Paul" }, { "family_name": "Vari", "given_name": "Riccardo", "clpid": "Vari-Riccardo" }, { "family_name": "Watson", "given_name": "Nigel", "clpid": "Watson-Nigel" }, { "family_name": "Williams", "given_name": "Mike", "clpid": "Wiliams-Mike" } ], "abstract": "This document presents the physics case and ancillary studies for the proposed CODEX-b long-lived particle (LLP) detector, as well as for a smaller proof-of-concept demonstrator detector, CODEX-\u03b2, to be operated during Run 3 of the LHC. Our development of the CODEX-b physics case synthesizes 'top-down' and 'bottom-up' theoretical approaches, providing a detailed survey of both minimal and complete models featuring LLPs. Several of these models have not been studied previously, and for some others we amend studies from previous literature: In particular, for gluon and fermion-coupled axion-like particles. We moreover present updated simulations of expected backgrounds in CODEX-b's actively shielded environment, including the effects of shielding propagation uncertainties, high-energy tails and variation in the shielding design. Initial results are also included from a background measurement and calibration campaign. A design overview is presented for the CODEX-\u03b2 demonstrator detector, which will enable background calibration and detector design studies. Finally, we lay out brief studies of various design drivers of the CODEX-b experiment and potential extensions of the baseline design, including the physics case for a calorimeter element, precision timing, event tagging within LHCb, and precision low-momentum tracking.", "doi": "10.1140/epjc/s10052-020-08711-3", "issn": "1434-6044", "publisher": "Springer", "publication": "European Physical Journal. C, Particles and Fields", "publication_date": "2020-12", "series_number": "12", "volume": "80", "issue": "12", "pages": "Art. No. 1177" }, { "id": "authors:498p8-f4x14", "collection": "authors", "collection_id": "498p8-f4x14", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200928-132854491", "type": "article", "title": "New physics in B meson mixing: Future sensitivity and limitations", "author": [ { "family_name": "Charles", "given_name": "J\u00e9r\u00f4me", "orcid": "0000-0002-4858-192X", "clpid": "Charles-J\u00e9r\u00f4me" }, { "family_name": "Descotes-Genon", "given_name": "S\u00e9bastien", "orcid": "0000-0001-7512-4970", "clpid": "Descotes-Genon-S\u00e9bastien" }, { "family_name": "Ligeti", "given_name": "Zoltan", "orcid": "0000-0002-4830-5773", "clpid": "Ligeti-Zoltan" }, { "family_name": "Monteil", "given_name": "St\u00e9phane", "orcid": "0000-0001-5015-3353", "clpid": "Monteil-St\u00e9phane" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Trabelsi", "given_name": "Karim", "orcid": "0000-0001-6567-3036", "clpid": "Trabelsi-Karim" }, { "family_name": "Vale Silva", "given_name": "Luiz", "orcid": "0000-0002-7399-3272", "clpid": "Vale-Silva-Luiz" } ], "abstract": "The mixing of neutral mesons is sensitive to some of the highest scales probed in laboratory experiments. In light of the planned LHCb Upgrade II, a possible upgrade of Belle II, and the broad interest in flavor physics in the tera-Z phase of the proposed FCC-ee program, we study constraints on new physics contributions to B_d and B_s mixings which can be obtained in these benchmark scenarios. We explore the limitations of this program, and identify the measurement of |V_(cb)| as one of the key ingredients in which progress beyond current expectations is necessary to maximize future sensitivity. We speculate on possible solutions to this bottleneck. Given the current tension with the standard model (SM) in semileptonic B decays, we explore how its resolution may impact the search for new physics in mixing. Even if new physics has the same Cabibbo-Kobayashi-Maskawa and loop suppressions of flavor changing processes as the SM, the sensitivity will reach 2 TeV, and it can be much higher if any SM suppressions are lifted. We illustrate the discovery potential of this program.", "doi": "10.1103/physrevd.102.056023", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2020-09-01", "series_number": "5", "volume": "102", "issue": "5", "pages": "Art. No. 056023" }, { "id": "authors:6bckk-8bg85", "collection": "authors", "collection_id": "6bckk-8bg85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200925-104734634", "type": "article", "title": "Das ist der HAMMER: consistent new physics interpretations of semileptonic decays", "author": [ { "family_name": "Bernlochner", "given_name": "Florian U.", "clpid": "Bernlochner-Florian-U" }, { "family_name": "Duell", "given_name": "Stephan", "clpid": "Duell-Stephan" }, { "family_name": "Ligeti", "given_name": "Zoltan", "orcid": "0000-0002-4830-5773", "clpid": "Ligeti-Zoltan" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Robinson", "given_name": "Dean J.", "clpid": "Robinson-Dean-J" } ], "abstract": "Precise measurements of b \u2192 c\u03c4\u03bd\u0304 decays require large resource-intensive Monte Carlo (MC) samples, which incorporate detailed simulations of detector responses and physics backgrounds. Extracted parameters may be highly sensitive to the underlying theoretical models used in the MC generation. Because new physics (NP) can alter decay distributions and acceptances, the standard practice of fitting NP Wilson coefficients to SM-based measurements of the R(D(\u2217)) ratios can be biased. The newly developed Hammer software tool enables efficient reweighting of MC samples to arbitrary NP scenarios or to any hadronic matrix elements. We demonstrate how Hammer allows avoidance of biases through self-consistent fits directly to the NP Wilson coefficients. We also present example analyses that demonstrate the sizeable biases that can otherwise occur from naive NP interpretations of SM-based measurements. The Hammer library is presently interfaced with several existing experimental analysis frameworks and we provide an overview of its structure.", "doi": "10.1140/epjc/s10052-020-8304-0", "issn": "1434-6044", "publisher": "Springer", "publication": "European Physical Journal. C, Particles and Fields", "publication_date": "2020-09", "series_number": "9", "volume": "80", "issue": "9", "pages": "Art. No. 883" }, { "id": "authors:rx621-s4j84", "collection": "authors", "collection_id": "rx621-s4j84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190613-164151263", "type": "article", "title": "Mono-X versus direct searches: simplified models for dark matter at the LHC", "author": [ { "family_name": "Liew", "given_name": "Seng Pei", "clpid": "Liew-Seng-Pei" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Vichi", "given_name": "Alessandro", "clpid": "Vichi-Alessandro" }, { "family_name": "Zurek", "given_name": "Kathryn M.", "orcid": "0000-0002-2629-337X", "clpid": "Zurek-K-M" } ], "abstract": "We consider simplified models for dark matter (DM) at the LHC, focused on mono-Higgs, -Z or -b produced in the final state. Our primary purpose is to study the LHC reach of a relatively complete set of simplified models for these final states, while comparing the reach of the mono-X DM search against direct searches for the mediating particle. We find that direct searches for the mediating particle, whether in di-jets, jets+ \u0246_T, multi-b+ \u0246_T, or di-boson+ \u0246_T, are usually stronger. We draw attention to the cases that the mono-X search is strongest, which include regions of parameter space in inelastic DM, two Higgs doublet, and squark mediated production models with a compressed spectrum.", "doi": "10.1007/jhep06(2017)082", "issn": "1029-8479", "publisher": "Springer", "publication": "Journal of High Energy Physics", "publication_date": "2017-06", "series_number": "6", "volume": "2017", "issue": "6", "pages": "Art. No. 82" }, { "id": "authors:1satx-mzz71", "collection": "authors", "collection_id": "1satx-mzz71", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190619-113125473", "type": "article", "title": "Rays of light from the LHC", "author": [ { "family_name": "Knapen", "given_name": "Simon", "orcid": "0000-0002-6733-9231", "clpid": "Knapen-Simon" }, { "family_name": "Melia", "given_name": "Tom", "orcid": "0000-0001-8669-6958", "clpid": "Melia-Tom" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Zurek", "given_name": "Kathryn M.", "orcid": "0000-0002-2629-337X", "clpid": "Zurek-K-M" } ], "abstract": "We consider models for the di-photon resonance observed at ATLAS (with 3.6 fb^(\u22121)) and CMS (with 2.6 fb^(\u22121)). We find there is no conflict between the signal reported at 13 TeV and the constraints from both experiments at 8 TeV with 20.3 fb^(\u22121). We make a simple argument for why the decay to the \u03b3\u03b3 mode must be generated by additional, beyond the standard model (SM) states. We explore four viable options: (i) resonance production and decay through loops of messenger fermions or scalars, (ii) a resonant messenger which decays to the di-photon resonance + X, (iii) an edge configuration where A \u2192 B\u03b3 \u2192 C\u03b3\u03b3, and (iv) Hidden Valley-like models where the resonance decays to a pair of very light (sub-GeV) states, each of which in turn decays to a pair of collimated photons that cannot be distinguished from a single photon. Since in each case multiple new states have been introduced, a wealth of signatures is expected to ensue at run 2 of the LHC.", "doi": "10.1103/physrevd.93.075020", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2016-04-01", "series_number": "7", "volume": "93", "issue": "7", "pages": "Art. No. 075020" }, { "id": "authors:sf8ed-rjh89", "collection": "authors", "collection_id": "sf8ed-rjh89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190613-164148960", "type": "article", "title": "Monojet versus the rest of the world I: t-channel models", "author": [ { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Vichi", "given_name": "Alessandro", "clpid": "Vichi-Alessandro" }, { "family_name": "Zurek", "given_name": "Kathryn M.", "orcid": "0000-0002-2629-337X", "clpid": "Zurek-K-M" } ], "abstract": "Monojet searches using Effective Field Theory (EFT) operators are usually interpreted as a robust and model independent constraint on direct detection (DD) scattering cross-sections. At the same time, a mediator particle must be present to produce the dark matter (DM) at the LHC. This mediator particle may be produced on shell, so that direct searches for the mediating particle can constrain the effective operator being applied to monojet constraints. In this first paper, we do a case study on t-channel models in monojet searches, where the (Standard Model singlet) DM is pair produced via a t-channel mediating particle, whose supersymmetric analogue is the squark. We compare monojet constraints to direct constraints on single or pair production of the mediator from multi-jets plus missing energy searches and we identify the regions where the latter dominate over the former. We show that computing bounds using supersymmetric simplified models and in the narrow width approximation, as done in previous work in the literature, misses important quantitative effects. We perform a full event simulation and statistical analysis, and we compute the effects of both on- and off-shell production of the mediating particle, showing that for both the monojet and multi-jets plus missing energy searches, previously derived bounds provided more conservative bounds than what can be extracted by including all relevant processes in the simulation. Monojets and searches for super-symmetry (SUSY) provide comparable bounds on a wide range of the parameter space, with SUSY searches usually providing stronger bounds, except in the regions where the DM particle and the mediator are very mass degenerate. The EFT approximation rarely is able to reproduce the actual limits. In a second paper to follow, we consider the case of s-channel mediators.", "doi": "10.1007/jhep11(2014)024", "issn": "1029-8479", "publisher": "Springer", "publication": "Journal of High Energy Physics", "publication_date": "2014-11", "series_number": "11", "volume": "2014", "issue": "11", "pages": "Art. No. 24" }, { "id": "authors:5xggt-cmm15", "collection": "authors", "collection_id": "5xggt-cmm15", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140714-090925327", "type": "article", "title": "NMSSM Interpretation of the Galactic Center Excess", "author": [ { "family_name": "Cheung", "given_name": "Clifford", "orcid": "0000-0002-9983-9425", "clpid": "Cheung-Clifford" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Sanford", "given_name": "David", "clpid": "Sanford-David" }, { "family_name": "Shah", "given_name": "Nausheen R.", "clpid": "Shah-Nausheen-R" }, { "family_name": "Zurek", "given_name": "Kathryn M.", "orcid": "0000-0002-2629-337X", "clpid": "Zurek-K-M" } ], "abstract": "We explore models for the GeV Galactic Center Excess (GCE) observed by the Fermi Telescope, focusing on \u03c7\u03c7\u2192\u0192\u0192(bar) annihilation processes in the Z3 NMSSM. We begin by examining the requirements for a simplified model (parametrized by the couplings and masses of dark matter (DM) and mediator particles) to reproduce the GCE via \u03c7\u03c7\u2192\u0192\u0192^bar, while simultaneously thermally producing the observed relic abundance. We apply the results of our simplified model to the Z_3 NMSSM for Singlino/Higgsino~(S/H) or Bino/Higgsino~(B/H) DM. In the case of S/H DM, we find that the DM must be be very close to a pseudoscalar resonance to be viable, and large tan \u03b2 and positive values of \u03bc are preferred for evading direct detection constraints while simultaneously obtaining the observed Higgs mass. In the case of B/H DM, by contrast, the situation is much less tuned: annihilation generally occurs off-resonance, and for large tan \u03b2 direct detection constraints are easily satisfied by choosing \u03bc sufficiently large and negative. The B/H model generally has a light, largely MSSM-like pseudoscalar with no accompanying charged Higgs, which could be searched for at the LHC.", "doi": "10.1103/PhysRevD.90.075011", "issn": "1550-7998", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2014-10-01", "series_number": "7", "volume": "90", "issue": "7", "pages": "Art. No. 075011" }, { "id": "authors:tn0va-6kc76", "collection": "authors", "collection_id": "tn0va-6kc76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190621-090126435", "type": "monograph", "title": "Simplified Models for Dark Matter and Missing Energy Searches at the LHC", "author": [ { "family_name": "Abdallah", "given_name": "Jalal", "clpid": "Abdallah-J" }, { "family_name": "Ashkenazi", "given_name": "Adi", "clpid": "Ashkenazi-A" }, { "family_name": "Boveia", "given_name": "Antonio", "clpid": "Boveia-A" }, { "family_name": "Busoni", "given_name": "Giorgio", "clpid": "Busoni-G" }, { "family_name": "de Simone", "given_name": "Andrea", "clpid": "de-Simone-A" }, { "family_name": "Doglioni", "given_name": "Caterina", "clpid": "Doglioni-C" }, { "family_name": "Efrati", "given_name": "Aielet", "clpid": "Efrati-A" }, { "family_name": "Etzion", "given_name": "Erez", "clpid": "Etzion-E" }, { "family_name": "Gramling", "given_name": "Johanna", "clpid": "Gramling-J" }, { "family_name": "Jacques", "given_name": "Thomas", "clpid": "Jacques-T" }, { "family_name": "Lin", "given_name": "Tongyan", "orcid": "0000-0003-4969-3285", "clpid": "Lin-Tongyan" }, { "family_name": "Morgante", "given_name": "Enrico", "clpid": "Morgante-E" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Penning", "given_name": "Bjoern", "clpid": "Penning-B" }, { "family_name": "Riotto", "given_name": "Antonio Walter", "clpid": "Riotto-A-W" }, { "family_name": "Rizzo", "given_name": "Thomas", "clpid": "Rizzo-T" }, { "family_name": "Salek", "given_name": "David", "clpid": "Salek-D" }, { "family_name": "Schramm", "given_name": "Steven", "clpid": "Schramm-S" }, { "family_name": "Slone", "given_name": "Oren", "clpid": "Slone-O" }, { "family_name": "Soreq", "given_name": "Yotam", "clpid": "Soreq-Y" }, { "family_name": "Vichi", "given_name": "Alessandro", "clpid": "Vichi-Alessandro" }, { "family_name": "Volansky", "given_name": "Tomer", "clpid": "Volansky-T" }, { "family_name": "Yavin", "given_name": "Itay", "clpid": "Yavin-I" }, { "family_name": "Zhou", "given_name": "Ning", "clpid": "Zhou-Ning" }, { "family_name": "Zurek", "given_name": "Kathryn", "orcid": "0000-0002-2629-337X", "clpid": "Zurek-K-M" } ], "abstract": "The study of collision events with missing energy as searches for the dark matter (DM) component of the Universe are an essential part of the extensive program looking for new physics at the LHC. Given the unknown nature of DM, the interpretation of such searches should be made broad and inclusive. This report reviews the usage of simplified models in the interpretation of missing energy searches. We begin with a brief discussion of the utility and limitation of the effective field theory approach to this problem. The bulk of the report is then devoted to several different simplified models and their signatures, including s-channel and t-channel processes. A common feature of simplified models for DM is the presence of additional particles that mediate the interactions between the Standard Model and the particle that makes up DM. We consider these in detail and emphasize the importance of their inclusion as final states in any coherent interpretation. We also review some of the experimental progress in the field, new signatures, and other aspects of the searches themselves. We conclude with comments and recommendations regarding the use of simplified models in Run-II of the LHC.", "doi": "10.48550/arXiv.1409.2893", "publisher": "arXiv", "publication_date": "2014-09-09" }, { "id": "authors:j1d51-f8d17", "collection": "authors", "collection_id": "j1d51-f8d17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190613-164147888", "type": "article", "title": "Higgs and dark matter hints of an oasis in the desert", "author": [ { "family_name": "Cheung", "given_name": "Clifford", "orcid": "0000-0002-9983-9425", "clpid": "Cheung-Clifford" }, { "family_name": "Papucci", "given_name": "Michele", "orcid": "0000-0003-0810-0017", "clpid": "Papucci-Michele" }, { "family_name": "Zurek", "given_name": "Kathryn M.", "orcid": "0000-0002-2629-337X", "clpid": "Zurek-K-M" } ], "abstract": "Recent LHC results suggest a standard model (SM)-like Higgs boson in the vicinity of 125 GeV with no clear indications yet of physics beyond the SM. At the same time, the SM is incomplete, since additional dynamics are required to accommodate cosmological dark matter (DM). In this paper we show that interactions between weak scale DM and the Higgs which are strong enough to yield a thermal relic abundance consistent with observation can easily destabilize the electroweak vacuum or drive the theory into a non-perturbative regime at a low scale. As a consequence, new physics \u2014 beyond the DM itself \u2014 must enter at a cutoff well below the Planck scale and in some cases as low as O(10-1000 TeV), a range relevant to indirect probes of flavor and CP violation. In addition, this cutoff is correlated with the DM mass and scattering cross-section in a parameter space which will be probed experimentally in the near term. Specifically, we consider the SM plus additional spin 0 or 1/2 states with singlet, triplet, or doublet electroweak quantum numbers and quartic or Yukawa couplings to the Higgs boson. We derive explicit expressions for the full two-loop RGEs and one-loop threshold corrections for these theories.", "doi": "10.1007/jhep07(2012)105", "issn": "1029-8479", "publisher": "Springer", "publication": "Journal of High Energy Physics", "publication_date": "2012-07", "series_number": "7", "volume": "2012", "issue": "7", "pages": "Art. No. 105" } ]