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Aebischer J, Isidori G, Pesut M, Stefanek BA, Wilsch F. Confronting the vector leptoquark hypothesis with new low- and high-energy data. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2023; 83:153. [PMID: 36820274 PMCID: PMC9935689 DOI: 10.1140/epjc/s10052-023-11304-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
In light of new data we present an updated phenomenological analysis of the simplified U 1 -leptoquark model addressing charged-current B-meson anomalies. The analysis shows a good compatibility of low-energy data (dominated by the lepton flavor universality ratios R D and R D ∗ ) with the high-energy constraints posed by p p → τ τ ¯ Drell-Yan data. We also show that present data are well compatible with a framework where the leptoquark couples with similar strength to both left- and right-handed third-generation fermions, a scenario that is well-motivated from a model building perspective. We find that the high-energy implications of this setup will be probed at the 95% confidence level in the high-luminosity phase of the LHC.
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Affiliation(s)
- Jason Aebischer
- Physik-Institut, Universität Zürich, 8057 Zürich, Switzerland
| | - Gino Isidori
- Physik-Institut, Universität Zürich, 8057 Zürich, Switzerland
| | - Marko Pesut
- Physik-Institut, Universität Zürich, 8057 Zürich, Switzerland
| | - Ben A. Stefanek
- Physik-Institut, Universität Zürich, 8057 Zürich, Switzerland
| | - Felix Wilsch
- Physik-Institut, Universität Zürich, 8057 Zürich, Switzerland
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Marzocca D, Trifinopoulos S. Minimal Explanation of Flavor Anomalies: B-Meson Decays, Muon Magnetic Moment, and the Cabibbo Angle. PHYSICAL REVIEW LETTERS 2021; 127:061803. [PMID: 34420345 DOI: 10.1103/physrevlett.127.061803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
Significant deviations from the standard model are observed in semileptonic charged and neutral-current B decays, the muon magnetic moment, and the extraction of the Cabibbo angle. We propose that these deviations point towards a coherent pattern of new physics effects induced by two scalar mediators, a leptoquark S_{1} and a charged singlet ϕ^{+}. While S_{1} can provide solutions to charged-current B decays and the muon magnetic moment, and ϕ^{+} can accommodate the Cabibbo-angle anomaly independently, their one-loop level synergy can also address neutral-current B decays. This framework provides the most minimal explanation to the above-mentioned anomalies, while being consistent with all other phenomenological constraints.
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Affiliation(s)
- David Marzocca
- INFN, Sezione di Trieste, SISSA, Via Bonomea 265, 34136 Trieste, Italy
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Crivellin A, Manzari CA, Algueró M, Matias J. Combined Explanation of the Z→bb[over ¯] Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, and τ→μνν and b→sℓ^{+}ℓ^{-} Data. PHYSICAL REVIEW LETTERS 2021; 127:011801. [PMID: 34270315 DOI: 10.1103/physrevlett.127.011801] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 06/01/2021] [Indexed: 06/13/2023]
Abstract
In this Letter, we propose a simple model that can provide a combined explanation of the Z→bb[over ¯] forward-backward asymmetry, the Cabibbo angle anomaly (CAA), τ→μνν and b→sℓ^{+}ℓ^{-} data. This model is obtained by extending the standard model (SM) by two heavy vectorlike quarks (an SU(2)_{L} doublet (singlet) with hypercharge -5/6 (-1/3), two new scalars (a neutral and a singly charged one), and a gauged L_{μ}-L_{τ} symmetry. The mixing of the new quarks with the SM ones, after electroweak symmetry breaking, does not only explain Z→bb[over ¯] data, but also generates a lepton flavor universal contribution to b→sℓ^{+}ℓ^{-} transitions. Together with the lepton flavor universality violating effect, generated by loop-induced Z^{'} penguins involving the charged scalar and the heavy quarks, it gives an excellent fit to data (6.1σ better than the SM). Furthermore, the charged scalar (neutral vector) gives a necessarily constructive tree-level (loop) effect in μ→eνν (τ→μνν), which can naturally account for the CAA (Br[τ→μνν]/Br[τ→eνν] and Br[τ→μνν]/Br[μ→eνν]).
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Affiliation(s)
- Andreas Crivellin
- CERN Theory Division, CH-1211 Geneva 23, Switzerland; Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland and Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Claudio Andrea Manzari
- Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland and Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Marcel Algueró
- Grup de Fisica Teòrica (Departament de Fisica), Universitat Autònoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain and Institut de Fisica d'Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, E-08193 Bellaterra, Barcelona, Spain
| | - Joaquim Matias
- Grup de Fisica Teòrica (Departament de Fisica), Universitat Autònoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain and Institut de Fisica d'Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, E-08193 Bellaterra, Barcelona, Spain
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Greljo A, Opferkuch T, Stefanek BA. Gravitational Imprints of Flavor Hierarchies. PHYSICAL REVIEW LETTERS 2020; 124:171802. [PMID: 32412299 DOI: 10.1103/physrevlett.124.171802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 04/16/2020] [Indexed: 06/11/2023]
Abstract
The mass hierarchy among the three generations of quarks and charged leptons is one of the greatest mysteries in particle physics. In various flavor models, the origin of this phenomenon is attributed to a series of hierarchical spontaneous symmetry breakings, most of which are beyond the reach of particle colliders. We point out that the observation of a multipeaked stochastic gravitational wave signal from a series of cosmological phase transitions could well be a unique probe of the mechanism behind flavor hierarchies. To illustrate this point, we show how near future ground- and space-based gravitational wave observatories could detect up to three peaks in the recently proposed PS^{3} model.
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Affiliation(s)
- Admir Greljo
- Theoretical Physics Department, CERN, 1211 Geneva, Switzerland
| | - Toby Opferkuch
- Theoretical Physics Department, CERN, 1211 Geneva, Switzerland
| | - Ben A Stefanek
- PRISMA Cluster of Excellence and Mainz Institute for Theoretical Physics, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
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Gómez JD, Quintero N, Rojas E. Charged current
b→cτν¯τ
anomalies in a general
W′
boson scenario. Int J Clin Exp Med 2019. [DOI: 10.1103/physrevd.100.093003] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Alves A, Éboli OJ, Grilli di Cortona G, Moreira RR. Indirect and monojet constraints on scalar leptoquarks. Int J Clin Exp Med 2019. [DOI: 10.1103/physrevd.99.095005] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Greljo A, Martin Camalich J, Ruiz-Álvarez JD. Mono-τ Signatures at the LHC Constrain Explanations of B-decay Anomalies. PHYSICAL REVIEW LETTERS 2019; 122:131803. [PMID: 31012623 DOI: 10.1103/physrevlett.122.131803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Indexed: 06/09/2023]
Abstract
We investigate the crossing-symmetry relation between b→cτ^{-}ν[over ¯] decay and bc[over ¯]→τ^{-}ν[over ¯] scattering to derive direct correlations of new physics in semitauonic B-meson decays and the mono-tau signature at the LHC (pp→τ_{h}X+MET). Using an exhaustive set of effective operators and heavy mediators we find that the current ATLAS and CMS data constrain scenarios addressing anomalies in B decays. Pure tensor solutions, completed by leptoquark, and right-handed solutions, completed by W_{R}^{'} or leptoquark, are challenged by our analysis. Furthermore, the sensitivity that will be achieved in the high-luminosity phase of the LHC will probe all the possible scenarios that explain the anomalies. Finally, we note that the LHC is also competitive in the b→u transitions and bounds in some cases are currently better than those from B decays.
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Affiliation(s)
- Admir Greljo
- Theoretical Physics Department, CERN, 1 Esplanade des Particules, 1211 Geneva 23, Switzerland
| | - Jorge Martin Camalich
- Theoretical Physics Department, CERN, 1 Esplanade des Particules, 1211 Geneva 23, Switzerland
- Instituto de Astrofísica de Canarias, C/ Vía Láctea, s/n E38205-La Laguna, Tenerife, Spain
- Universidad de La Laguna, Departamento de Astrofísica, 38200-La Laguna, Tenerife, Spain
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Crivellin A, Greub C, Saturnino F, Müller D. Importance of Loop Effects in Explaining the Accumulated Evidence for New Physics in B Decays with a Vector Leptoquark. PHYSICAL REVIEW LETTERS 2019; 122:011805. [PMID: 31012659 DOI: 10.1103/physrevlett.122.011805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Indexed: 06/09/2023]
Abstract
In recent years experiments revealed intriguing hints for new physics (NP) in B decays involving b→cτν and b→sℓ^{+}ℓ^{-} transitions at the 4σ and 5σ level, respectively. In addition, there are slight disagreements in b→uτν and b→dμ^{+}μ^{-} observables. While not significant on their own, they point in the same direction. Furthermore, V_{us} extracted from τ decays shows a slight tension (≈2.5σ) with its value determined from Cabibbo-Kobayashi-Maskawa unitarity, and an analysis of BELLE data found an excess in B_{d}→τ^{+}τ^{-}. Concerning NP explanations, the vector leptoquark SU(2) singlet is of special interest since it is the only single particle extension of the standard model which can (in principle) address all the anomalies described above. For this purpose, large couplings to τ leptons are necessary and loop effects, which we calculate herein, become important. Including them in our phenomenological analysis, we find that neither the tension in V_{us} nor the excess in B_{d}→τ^{+}τ^{-} can be fully explained without violating bounds from K→πνν[over ¯]. However, one can account for b→cτν and b→uτν data finding intriguing correlations with B_{q}→τ^{+}τ^{-} and K→πνν[over ¯]. Furthermore, the explanation of b→cτν predicts a positive shift in C_{7} and a negative one in C_{9}, being nicely in agreement with the global fit to b→sℓ^{+}ℓ^{-} data. Finally, we point out that one can fully account for b→cτν and b→sℓ^{+}ℓ^{-} without violating bounds from τ→ϕμ, ϒ→τμ, or b→sτμ processes.
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Affiliation(s)
| | - Christoph Greub
- Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, CH-3012 Bern, Switzerland
| | - Francesco Saturnino
- Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, CH-3012 Bern, Switzerland
| | - Dario Müller
- Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland and Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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Abdullah M, Calle J, Dutta B, Flórez A, Restrepo D. Probing a simplified
W′
model of
R(D(*))
anomalies using
b
tags,
τ
leptons, and missing energy. Int J Clin Exp Med 2018. [DOI: 10.1103/physrevd.98.055016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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Fraser S, Marzo C, Marzola L, Raidal M, Spethmann C. Towards a viable scalar interpretation of
RD(*). Int J Clin Exp Med 2018. [DOI: 10.1103/physrevd.98.035016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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