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Global Analysis of Leptophilic $Z^\prime$ Bosons
/ Buras, Andrzej J. (TUM-IAS, Munich) ; Crivellin, Andreas (CERN ; Zurich U. ; PSI, SLS) ; Kirk, Fiona (Zurich U. ; PSI, SLS) ; Manzari, Claudio Andrea (Zurich U. ; PSI, SLS) ; Montull, Marc (Zurich U. ; PSI, SLS)
New neutral heavy gauge bosons ($Z^\prime$) are predicted within many extensions of the Standard Model. While in case they couple to quarks the LHC bounds are very stringent, leptophilic $Z^\prime$ bosons (even with sizable couplings) can be much lighter and therefore lead to interesting quantum effects in precision observables (like $(g-2)_\mu$) and generate flavour violating decays of charged leptons. [...]
arXiv:2104.07680; AJB-21-3; CERN-56; PSI-PR-21-06; ZU-TH 15/20.-
2021-06-09 - 48 p.
- Published in : JHEP 2106 (2021) 068
Article from SCOAP3: PDF; Fulltext: PDF;
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2.
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Anatomy of a new anomaly in non-leptonic B decays
/ Algueró, M. (Barcelona, IFAE ; Barcelona, Autonoma U.) ; Crivellin, A. (CERN ; Zurich U. ; PSI, Villigen) ; Descotes-Genon, S. (IJCLab, Orsay) ; Matias, J. (Barcelona, IFAE ; Barcelona, Autonoma U.) ; Novoa-Brunet, M. (IJCLab, Orsay)
We discuss the anatomy of the $L_{VV}$ observable designed as a ratio of the longitudinal components of $B_s \to VV$ versus $B_d \to VV$ decays. [...]
arXiv:2105.11837.
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4 p.
Fulltext
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3.
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Scalar Leptoquarks in Leptonic Processes
/ Crivellin, Andreas (CERN ; Zurich U. ; PSI, Villigen) ; Greub, Christoph (U. Bern, AEC) ; Müller, Dario (Zurich U. ; PSI, Villigen) ; Saturnino, Francesco (U. Bern, AEC)
Leptoquarks are hypothetical new particles, which couple quarks directly to leptons. They experienced a renaissance in recent years as they are prime candidates to explain the so-called \textit{flavor anomalies}, i.e. [...]
arXiv:2010.06593; CERN-TH-2020-167; PSI-20-17; ZU-TH 38/20.-
2021-02-22 - 60 p.
- Published in : JHEP 2102 (2021) 182
Article from SCOAP3: scoap3-fulltext - PDF; scoap - PDF; Fulltext: PDF;
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4.
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Global Electroweak Fit and Vector-Like Leptons in Light of the Cabibbo Angle Anomaly
/ Crivellin, Andreas (CERN ; Zurich U. ; PSI, Villigen) ; Kirk, Fiona (Zurich U. ; PSI, Villigen) ; Manzari, Claudio Andrea (Zurich U. ; PSI, Villigen) ; Montull, Marc (Zurich U. ; PSI, Villigen)
The "Cabibbo Angle Anomaly" (CAA) originates from the disagreement between the CKM elements $V_{ud}$ and $V_{us}$ extracted from superallowed beta and kaon decays, respectively, once compared via CKM unitarity. It points towards new physics with a significance of up to $4\,\sigma$, depending on the theoretical input used, and can be explained through modified $W$ couplings to leptons. [...]
arXiv:2008.01113; CERN-TH-2020-128; PSI-PR-20-11; UZ-TH 26/20.-
2020-12-28 - 34 p.
- Published in : JHEP 2020 (2020) 166
Article from SCOAP3: PDF; Fulltext: PDF;
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5.
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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
/ Crivellin, Andreas (CERN ; PSI, Villigen ; Zurich U.) ; Manzari, Claudio Andrea (PSI, Villigen ; Zurich U.) ; Alguero, Marcel (Barcelona, Autonoma U. ; Barcelona, IFAE) ; Matias, Joaquim (Barcelona, Autonoma U. ; Barcelona, IFAE)
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. [...]
arXiv:2010.14504; CERN-TH-2020-177; PSI-PR-20-18; UZ-TH 40/20.-
2021-07-02 - 8 p.
- Published in : Phys. Rev. Lett. 127 (2021) 011801
Fulltext: PDF; Fulltext from publisher: PDF;
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6.
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Correlating nonresonant di-electron searches at the LHC to the Cabibbo-angle anomaly and lepton flavor universality violation
/ Crivellin, Andreas (Zurich U. ; PSI, Villigen ; CERN) ; Manzari, Claudio Andrea (Zurich U. ; PSI, Villigen) ; Montull, Marc (Zurich U. ; PSI, Villigen)
In addition to the existing strong indications for lepton flavour university violation (LFUV) in low energy precision experiments, CMS recently released an analysis of non-resonant di-lepton pairs which could constitute the first sign of LFUV in high-energy LHC searches. In this article we show that the Cabibbo angle anomaly, an (apparent) violation of first row and column CKM unitarity with $\approx3\,\sigma$ significance, and the CMS result can be correlated and commonly explained in a model independent way by the operator $[Q_{\ell q}^{(3)}]_{1111} = (\bar{\ell}_1\gamma^{\mu}\sigma^I\ell_1)(\bar{q}_1\gamma_{\mu}\sigma^Iq_1)$. [...]
arXiv:2103.12003; CERN-TH-2021-036; PSI-PR-21-03; ZU-TH 11/21.-
2021-12-01 - 6 p.
- Published in : Phys. Rev. D 104 (2021) 115016
Fulltext: PhysRevD.104.115016 - PDF; 2103.12003 - PDF;
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7.
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Searching for Lepton Flavour (Universality) Violation and Collider Signals from a Singly-Charged Scalar Singlet
/ Crivellin, Andreas (CERN ; Zurich U. ; PSI, Villigen) ; Kirk, Fiona (Zurich U. ; PSI, Villigen) ; Manzari, Claudio Andrea (Zurich U. ; PSI, Villigen) ; Panizzi, Luca (Uppsala U.)
In recent years, evidence for lepton flavour universality violation beyond the Standard Model has been accumulated. In this context, a singly charged $SU(2)_L$ singlet scalar ($\phi^\pm$) is very interesting, as it can only have flavour off-diagonal couplings to neutrinos and charged leptons, therefore necessarily violating lepton flavour (universality). [...]
arXiv:2012.09845; CERN-TH-2020-213; PSI-PR-20-24; UZ-TH 55/20.-
2021-04-15 - 8 p.
- Published in : Phys. Rev. D 103 (2021) 073002
Article from SCOAP3: PDF; Fulltext: PDF;
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10.
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Modified lepton couplings and the Cabibbo-angle anomaly
/ Manzari, Claudio Andrea (Zurich U. ; PSI, Villigen) ; Coutinho, Antonio M. (PSI, Villigen) ; Crivellin, Andreas (Zurich U. ; PSI, Villigen ; CERN)
Significant discrepancies between the different determinations of the Cabibbo angle have been observed. Here, we point out that this "Cabibbo-angle anomaly" can be explained by lepton flavour universality (LFU) violating New Physics (NP) in the neutrino sector. [...]
arXiv:2009.03877.-
SISSA, 2021 - 8 p.
- Published in : PoS LHCP2020 (2021) 242
Fulltext: 2009.03877 - PDF; PoS(LHCP2020)242 - PDF;
In : 8th Conference of Large Hadron Collider Physics (LHCP), Online, 25 - 30 May 2020, pp.242
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