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Combined Explanation of the $Z\to b\bar b$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ Data
In this Letter, we propose a simple model that can provide a combined explanation of the <math display="inline"><mi>Z</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy=&quo...
| Autores principales: | , , , |
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| Lenguaje: | eng |
| Publicado: |
2020
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| Materias: | |
| Acceso en línea: | https://dx.doi.org/10.1103/PhysRevLett.127.011801 http://cds.cern.ch/record/2743015 |
| _version_ | 1780968534185082880 |
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| author | Crivellin, Andreas Manzari, Claudio Andrea Alguero, Marcel Matias, Joaquim |
| author_facet | Crivellin, Andreas Manzari, Claudio Andrea Alguero, Marcel Matias, Joaquim |
| author_sort | Crivellin, Andreas |
| collection | CERN |
| description | In this Letter, we propose a simple model that can provide a combined explanation of the <math display="inline"><mi>Z</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> forward-backward asymmetry, the Cabibbo angle anomaly (CAA), <math display="inline"><mi>τ</mi><mo stretchy="false">→</mo><mi>μ</mi><mi>ν</mi><mi>ν</mi></math> and <math display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msup><mo>ℓ</mo><mo>-</mo></msup></math> data. This model is obtained by extending the standard model (SM) by two heavy vectorlike quarks (an <math display="inline"><mi>SU</mi><mo stretchy="false">(</mo><mn>2</mn><msub><mo stretchy="false">)</mo><mi>L</mi></msub></math> doublet (singlet) with hypercharge <math display="inline"><mo>-</mo><mn>5</mn><mo stretchy="false">/</mo><mn>6</mn></math> (<math display="inline"><mo>-</mo><mn>1</mn><mo stretchy="false">/</mo><mn>3</mn></math>), two new scalars (a neutral and a singly charged one), and a gauged <math display="inline"><msub><mi>L</mi><mi>μ</mi></msub><mo>-</mo><msub><mi>L</mi><mi>τ</mi></msub></math> symmetry. The mixing of the new quarks with the SM ones, after electroweak symmetry breaking, does not only explain <math display="inline"><mi>Z</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> data, but also generates a lepton flavor universal contribution to <math display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msup><mo>ℓ</mo><mo>-</mo></msup></math> transitions. Together with the lepton flavor universality violating effect, generated by loop-induced <math display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> penguins involving the charged scalar and the heavy quarks, it gives an excellent fit to data (<math display="inline"><mn>6.1</mn><mi>σ</mi></math> better than the SM). Furthermore, the charged scalar (neutral vector) gives a necessarily constructive tree-level (loop) effect in <math display="inline"><mi>μ</mi><mo stretchy="false">→</mo><mi>e</mi><mi>ν</mi><mi>ν</mi></math> (<math display="inline"><mi>τ</mi><mo stretchy="false">→</mo><mi>μ</mi><mi>ν</mi><mi>ν</mi></math>), which can naturally account for the CAA (<math display="inline"><mtext>Br</mtext><mo stretchy="false">[</mo><mi>τ</mi><mo stretchy="false">→</mo><mi>μ</mi><mi>ν</mi><mi>ν</mi><mo stretchy="false">]</mo><mo stretchy="false">/</mo><mtext>Br</mtext><mo stretchy="false">[</mo><mi>τ</mi><mo stretchy="false">→</mo><mi>e</mi><mi>ν</mi><mi>ν</mi><mo stretchy="false">]</mo></math> and <math display="inline"><mtext>Br</mtext><mo stretchy="false">[</mo><mi>τ</mi><mo stretchy="false">→</mo><mi>μ</mi><mi>ν</mi><mi>ν</mi><mo stretchy="false">]</mo><mo stretchy="false">/</mo><mtext>Br</mtext><mo stretchy="false">[</mo><mi>μ</mi><mo stretchy="false">→</mo><mi>e</mi><mi>ν</mi><mi>ν</mi><mo stretchy="false">]</mo></math>). |
| id | cern-2743015 |
| institution | Organización Europea para la Investigación Nuclear |
| language | eng |
| publishDate | 2020 |
| record_format | invenio |
| spelling | cern-27430152023-07-27T04:06:44Zdoi:10.1103/PhysRevLett.127.011801http://cds.cern.ch/record/2743015engCrivellin, AndreasManzari, Claudio AndreaAlguero, MarcelMatias, JoaquimCombined Explanation of the $Z\to b\bar b$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ Datanucl-thNuclear Physics - Theorynucl-exNuclear Physics - Experimenthep-exParticle Physics - Experimenthep-phParticle Physics - PhenomenologyIn this Letter, we propose a simple model that can provide a combined explanation of the <math display="inline"><mi>Z</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> forward-backward asymmetry, the Cabibbo angle anomaly (CAA), <math display="inline"><mi>τ</mi><mo stretchy="false">→</mo><mi>μ</mi><mi>ν</mi><mi>ν</mi></math> and <math display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msup><mo>ℓ</mo><mo>-</mo></msup></math> data. This model is obtained by extending the standard model (SM) by two heavy vectorlike quarks (an <math display="inline"><mi>SU</mi><mo stretchy="false">(</mo><mn>2</mn><msub><mo stretchy="false">)</mo><mi>L</mi></msub></math> doublet (singlet) with hypercharge <math display="inline"><mo>-</mo><mn>5</mn><mo stretchy="false">/</mo><mn>6</mn></math> (<math display="inline"><mo>-</mo><mn>1</mn><mo stretchy="false">/</mo><mn>3</mn></math>), two new scalars (a neutral and a singly charged one), and a gauged <math display="inline"><msub><mi>L</mi><mi>μ</mi></msub><mo>-</mo><msub><mi>L</mi><mi>τ</mi></msub></math> symmetry. The mixing of the new quarks with the SM ones, after electroweak symmetry breaking, does not only explain <math display="inline"><mi>Z</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> data, but also generates a lepton flavor universal contribution to <math display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msup><mo>ℓ</mo><mo>-</mo></msup></math> transitions. Together with the lepton flavor universality violating effect, generated by loop-induced <math display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> penguins involving the charged scalar and the heavy quarks, it gives an excellent fit to data (<math display="inline"><mn>6.1</mn><mi>σ</mi></math> better than the SM). Furthermore, the charged scalar (neutral vector) gives a necessarily constructive tree-level (loop) effect in <math display="inline"><mi>μ</mi><mo stretchy="false">→</mo><mi>e</mi><mi>ν</mi><mi>ν</mi></math> (<math display="inline"><mi>τ</mi><mo stretchy="false">→</mo><mi>μ</mi><mi>ν</mi><mi>ν</mi></math>), which can naturally account for the CAA (<math display="inline"><mtext>Br</mtext><mo stretchy="false">[</mo><mi>τ</mi><mo stretchy="false">→</mo><mi>μ</mi><mi>ν</mi><mi>ν</mi><mo stretchy="false">]</mo><mo stretchy="false">/</mo><mtext>Br</mtext><mo stretchy="false">[</mo><mi>τ</mi><mo stretchy="false">→</mo><mi>e</mi><mi>ν</mi><mi>ν</mi><mo stretchy="false">]</mo></math> and <math display="inline"><mtext>Br</mtext><mo stretchy="false">[</mo><mi>τ</mi><mo stretchy="false">→</mo><mi>μ</mi><mi>ν</mi><mi>ν</mi><mo stretchy="false">]</mo><mo stretchy="false">/</mo><mtext>Br</mtext><mo stretchy="false">[</mo><mi>μ</mi><mo stretchy="false">→</mo><mi>e</mi><mi>ν</mi><mi>ν</mi><mo stretchy="false">]</mo></math>).In this article we propose a simple model which can provide a combined explanation of the $Z\to b\bar b$ forward-backward asymmetry, the Cabibbo Angle Anomaly (CAA), $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ data. This model is obtained by extending the Standard Model (SM) by two heavy vector-like 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 $L_\mu-L_\tau$ symmetry. The mixing of the new quarks with the SM ones, after electroweak symmetry breaking, does not only explain $Z\to b\bar b$ data but also generates a lepton flavour universal contribution to $b\to s\ell^+\ell^-$ transitions. Together with the lepton flavour universality violating effect, generated by loop-induced $Z^\prime$ penguins involving the charged scalar and the heavy quarks, it gives an excellent fit to data ($6.1\,\sigma$ better than the SM). Furthermore, the charged scalar (neutral vector) gives a necessarily constructive tree-level (loop) effect in $\mu\to e\nu\nu$ ($\tau\to \mu\nu\nu$), which can naturally account for the CAA (${\rm Br}[\tau\to\mu\nu\nu]/{\rm Br}[\tau\to e\nu\nu]$ and ${\rm Br}[\tau\to\mu\nu\nu]/{\rm Br}[\mu\to e\nu\nu]$).arXiv:2010.14504CERN-TH-2020-177PSI-PR-20-18UZ-TH 40/20oai:cds.cern.ch:27430152020-10-27 |
| spellingShingle | nucl-th Nuclear Physics - Theory nucl-ex Nuclear Physics - Experiment hep-ex Particle Physics - Experiment hep-ph Particle Physics - Phenomenology Crivellin, Andreas Manzari, Claudio Andrea Alguero, Marcel Matias, Joaquim Combined Explanation of the $Z\to b\bar b$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ Data |
| title | Combined Explanation of the $Z\to b\bar b$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ Data |
| title_full | Combined Explanation of the $Z\to b\bar b$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ Data |
| title_fullStr | Combined Explanation of the $Z\to b\bar b$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ Data |
| title_full_unstemmed | Combined Explanation of the $Z\to b\bar b$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ Data |
| title_short | Combined Explanation of the $Z\to b\bar b$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ Data |
| title_sort | combined explanation of the $z\to b\bar b$ forward-backward asymmetry, the cabibbo angle anomaly, $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ data |
| topic | nucl-th Nuclear Physics - Theory nucl-ex Nuclear Physics - Experiment hep-ex Particle Physics - Experiment hep-ph Particle Physics - Phenomenology |
| url | https://dx.doi.org/10.1103/PhysRevLett.127.011801 http://cds.cern.ch/record/2743015 |
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