002743015 001__ 2743015
002743015 005__ 20231124082519.0
002743015 0248_ $$aoai:cds.cern.ch:2743015$$pcerncds:FULLTEXT$$pcerncds:CERN:FULLTEXT$$pcerncds:CERN
002743015 0247_ $$2DOI$$9APS$$a10.1103/PhysRevLett.127.011801$$qpublication
002743015 037__ $$9arXiv$$aarXiv:2010.14504$$chep-ph
002743015 037__ $$9arXiv:reportnumber$$aCERN-TH-2020-177
002743015 037__ $$9arXiv:reportnumber$$aPSI-PR-20-18
002743015 037__ $$9arXiv:reportnumber$$aUZ-TH 40/20
002743015 035__ $$9arXiv$$aoai:arXiv.org:2010.14504
002743015 035__ $$9Inspire$$aoai:inspirehep.net:1826415$$d2023-11-23T10:41:59Z$$h2023-11-24T03:01:18Z$$mmarcxml$$ttrue$$uhttps://inspirehep.net/api/oai2d
002743015 035__ $$9Inspire$$a1826415
002743015 041__ $$aeng
002743015 100__ $$aCrivellin, [email protected]$$uCERN$$uPSI, Villigen$$uZurich U.$$vCERN 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
002743015 245__ $$9arXiv$$aCombined 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
002743015 246__ $$9APS$$aCombined Explanation of the Z→bb¯ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, and τ→μνν and b→sℓ+ℓ- Data
002743015 269__ $$c2020-10-27
002743015 260__ $$c2021-07-02
002743015 300__ $$a8 p
002743015 500__ $$9arXiv$$a8 pages, 2 figures, version accepted for publication in PRL
002743015 520__ $$9APS$$aIn 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>).
002743015 520__ $$9arXiv$$aIn this article we propose a simple model which can provide a combined explanation of the $Z\to b\bar b$ forward-backward asymmetry, the Cabibbo Angle Anomaly (CAA), $\tau\to\mu\nu\nu$ and $b\to s\ell^+\ell^-$ data. This model is obtained by extending the Standard Model (SM) by two heavy vector-like quarks (an $SU(2)_L$ doublet (singlet) with hypercharge $-5/6$ (-1/3)), two new scalars (a neutral and a singly charged one) and a gauged $L_\mu-L_\tau$ symmetry. The mixing of the new quarks with the SM ones, after electroweak symmetry breaking, does not only explain $Z\to b\bar b$ data but also generates a lepton flavour universal contribution to $b\to s\ell^+\ell^-$ transitions. Together with the lepton flavour universality violating effect, generated by loop-induced $Z^\prime$ penguins involving the charged scalar and the heavy quarks, it gives an excellent fit to data ($6.1\,\sigma$ better than the SM). Furthermore, the charged scalar (neutral vector) gives a necessarily constructive tree-level (loop) effect in $\mu\to e\nu\nu$ ($\tau\to \mu\nu\nu$), which can naturally account for the CAA (${\rm Br}[\tau\to\mu\nu\nu]/{\rm Br}[\tau\to e\nu\nu]$ and ${\rm Br}[\tau\to\mu\nu\nu]/{\rm Br}[\mu\to e\nu\nu]$).
002743015 540__ $$3preprint$$aarXiv nonexclusive-distrib 1.0$$uhttp://arxiv.org/licenses/nonexclusive-distrib/1.0/
002743015 540__ $$3publication$$aCC BY 4.0$$fSCOAP3$$uhttps://creativecommons.org/licenses/by/4.0/
002743015 542__ $$3publication$$dauthors$$fPublished by the American Physical Society$$g2021
002743015 595__ $$aCERN-TH
002743015 65017 $$2arXiv$$anucl-th
002743015 65017 $$2SzGeCERN$$aNuclear Physics - Theory
002743015 65017 $$2arXiv$$anucl-ex
002743015 65017 $$2SzGeCERN$$aNuclear Physics - Experiment
002743015 65017 $$2arXiv$$ahep-ex
002743015 65017 $$2SzGeCERN$$aParticle Physics - Experiment
002743015 65017 $$2arXiv$$ahep-ph
002743015 65017 $$2SzGeCERN$$aParticle Physics - Phenomenology
002743015 690C_ $$aCERN
002743015 690C_ $$aARTICLE
002743015 700__ $$aManzari, Claudio [email protected]$$uPSI, Villigen$$uZurich U.$$vPaul Scherrer Institut, CH–5232 Villigen PSI, Switzerland and Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH–8057 Zürich, Switzerland
002743015 700__ $$aAlguero, [email protected]$$uBarcelona, Autonoma U.$$uBarcelona, IFAE$$vGrup de Fisica Teòrica (Departament de Fisica), Universitat Autònoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain and Institut de Fisica d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, E-08193 Bellaterra, Barcelona, Spain
002743015 700__ $$aMatias, [email protected]$$uBarcelona, Autonoma U.$$uBarcelona, IFAE$$vGrup de Fisica Teòrica (Departament de Fisica), Universitat Autònoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain and Institut de Fisica d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, E-08193 Bellaterra, Barcelona, Spain
002743015 773__ $$c011801$$mpublication$$n1$$pPhys. Rev. Lett.$$v127$$xPhys. Rev. Lett. 127, 011801 (2021)$$y2021
002743015 8564_ $$82258591$$s3156$$uhttps://cds.cern.ch/record/2743015/files/ZqqLModified.png$$y00001 Diagrams generating modified $Zbb$ and $Zbs$ couplings due to the mixing of the heavy quarks with the SM-like ones after EWSB. In addition, one-particle reducible diagrams exist which are not depicted here.
002743015 8564_ $$82258592$$s2759$$uhttps://cds.cern.ch/record/2743015/files/muenunu.png$$y00002 Feynman diagrams showing the $\phi^-$ contribution to muon decay.
002743015 8564_ $$82258593$$s89670$$uhttps://cds.cern.ch/record/2743015/files/bsllBsmixing.png$$y00001 Preferred and excluded regions in the $m_Q$-$m_\phi$ plane for $\kappa_s\kappa_s^*=-0.3$ and $m_Q=m_D$. Note that for $m_Qm_\phi>1.5{\rm TeV}^2$ one can account for $b\to s\ell^+\ell^-$ data while being in agreement with $B_s-\bar B_s$ mixing at the $1\,\sigma$ level.
002743015 8564_ $$82258594$$s883198$$uhttps://cds.cern.ch/record/2743015/files/2010.14504.pdf$$yFulltext
002743015 8564_ $$82258595$$s4670$$uhttps://cds.cern.ch/record/2743015/files/Zpbs.png$$y00003 Feynman diagrams inducing a $Z^{\prime}$ coupling to down quarks at the loop level. Note that the $Z^\prime$ can couple both to $Q$ and $\phi^+$ and that our \eq{Zpdd} contains the resummation of insertions of $v_S$ to all orders.
002743015 8564_ $$82258596$$s3192$$uhttps://cds.cern.ch/record/2743015/files/ZqqRModified.png$$y00000 Diagrams generating modified $Zbb$ and $Zbs$ couplings due to the mixing of the heavy quarks with the SM-like ones after EWSB. In addition, one-particle reducible diagrams exist which are not depicted here.
002743015 8564_ $$82300516$$s92589$$uhttps://cds.cern.ch/record/2743015/files/FullPlot.png$$y00000 Diagramatic representation of how the Feynman diagrams (A)-(D) within our model contribute to $Z\to \bar{b}b(\bar{s}s)$, muon decay, $\tau\to\mu\nu\nu$ and $b\to s\ell\ell$ and explain the associated anomalies.
002743015 8564_ $$82310795$$s916059$$uhttps://cds.cern.ch/record/2743015/files/PhysRevLett.127.011801.pdf$$yFulltext from publisher
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002743015 8564_ $$82310795$$s180857$$uhttps://cds.cern.ch/record/2743015/files/PhysRevLett.127.011801.jpg?subformat=icon-700$$xicon-700$$yFulltext from publisher
002743015 8564_ $$82310795$$s31221$$uhttps://cds.cern.ch/record/2743015/files/PhysRevLett.127.011801.jpg?subformat=icon-180$$xicon-180$$yFulltext from publisher
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002743015 980__ $$aARTICLE