Contents

# Contents

## Idea

In the current standard model of particle physics the fundamental particles in the three generations of fermions have identical properties from one generation to the next, except for their mass, a state of affairs referred to as lepton universality. A possible violation of lepton universality is called a flavour anomaly, which would be a sign of “New Physics” (NP) beyond the standard model.

See Alonso 19 for general introduction to an audience with basic background in quantum field theory.

graphics grabbed from Cartelle 18

## Statistical significance

Indications of flavour anomalies have been observed consistently and with increasing statistical significance around $2.5-3$ σ in B meson processes in various channels by a number of independent experiments: the LHCb experiment, the Belle experiment and the BaBar experiment:

table grabbed from BGV 19

The global (all channels and experiments combined) tension with the standard model by end of 2018 had statistical significance around $4.1$ σ (Strumia et al. 17, Cartelle 18, slide 22/25, Dey 18, slide 16/23, HAMN 18, p. 4, Bouchard-Cao-Owen 19). Various authors see the global tension (i.e. of all decay channels jointly) at over $5 \sigma$ (CCDGMV 17, CFMVV 17 CGMS 18, Dordei 18, slide 12), which traditionally qualifies as detection (see here), some authors already quote $5.3 \sigma - 5.8 \sigma$ (ACDGMM 19) or $5-6 \sigma$ (Kumar-London 19, Kumar 19).

graphics grabbed from Dey 18

This situation was confirmed with the completed measurements presented at Moriond 2019, which showed (Straub 19, Allanach 19) smaller discrepancy but also with smaller uncertainty, thus keeping the statistical significance essentially unaffected. But in 2019 Caria 19, slide 9 report new numbers by Belle by which the previous statistical significance of $3.8 \sigma$ in the $R_D$ sector would decrease to $3.1 \sigma$ or $2.8 \sigma$ (Gambino-Jung-Schacht 19 (6)). See LHCb 19, p. 2 for how the new numbers come about. Comprehensive assessments of the situation after Moriond 2019 are given in AHMSN 19, Descotes-Genon 19, Bardhan-Ghosh 19, Alguero 19 and agree that the flavour anomalies have been confirmed:

It appears the reason is that, given the amount of independent measurements (~180!) a smaller deviation because of new physics is easier to accommodate than a large one. Thus the new measurements actually fit better with new physics.

(Axel Maas, reporting from ALPS2019, tweet, 23 Apr 2019)

The statistical significances of pull away from the stanmdard model for effective New Physics models:

table grabbed from Alguero 19

There is the claim (DGKV 19) that the discrepancy with the standard model increases further if non-trivial hadronic form factors are taken into account:

slide grabbed from Descotes-Genon 19b

If the ongoing evaluation of the data of LHC‘s Run 2 confirms the measurements of Run 1, then the statistical significance of the effect in each decay channel separately should have reached 5 σ (Crivellin et. al 18, p. 12, Zupan 19, 4.6) and hence conventionally count as detection of flavour anomaly (see here), which would make it the first established “new physics” seen at the LHC. More recent extrapolation based on LHCb Collaboration 18 predicts a statistical significance between 6 and 10 $\sigma$ by 2015 LKLR 19, p. 12 by they year 2025.

In fact, it had been argued prior to the detection of the anomalies (Lyons 13b, Dorigo 15) that due to the specific nature of the experiment, the statistical significance-threshold for detection of anomalies in B meson-decays should not be taken to be $5 \sigma$, but just $3 \sigma$, hence well exceeded already by the experimentally seen statistical significance:

table taken from Lyons 13b, p. 4

table taken from Dorigo 15, p. 16

This attitude is reflected in SGGJC 19, p. 2:

For some time now, the ratios of semileptonicB-decay rates have appeared to be enhanced with respect to the Standard Model (SM) predictions with a global significance above the evidence threshold.

## Status and Outlook

In conclusion, with currently available data, the observed flavour anomalies are possible signs of New Physics beyond the current standard model of particle physics.

graphics taken from Dordei 18, slide 22

In any case, further and more sensitive experiments are needed to confirm and explore the effect, such as possibly the “HL-LHC” or “HE-LHC” experiment. General outlook, prospects and suggestions for future collider design in this respect are discussed in detail in Allanach-Gripaios-You 17, Crivellin et al. 18.

From Isodori 19, slide 6:

## Possible models

Candidate models of “New Physics” beyond the standard model of particle physics that could possibly explain the flavour anomalies (if indeed they are real) includes the following:

### Leptoquarks and Grand unified theory

One promising model that could potentially explain the apparently observed flavour anomalies are leptoquarks, which naturally arise in, and hence potentially point to, grand unified theory models, such as notably the Pati-Salam model (Heek-Teresi 18, Heek-Teresi 19)

From Crivellin 18, p. 2:

the global fit $[$ to flavour anomalies $]$ even shows compelling evidence for New Physics $[$$]$ The vector leptoquark (LQ) $SU(2)_L$ singlet with hypercharge $-4/3$ arising in the famous Pati-Salam model is capable of explaining all the $[$flavour $]$ anomalies and therefore several attempts to construct a UV completion for this LQ to address the anomalies have been made. It can give a sizeable effect in $b \to c(u)\tau \nu$ data without violating bounds from $b \to s(d)\nu \bar \nu$ and/or direct searches, provides (at tree level) a $C_9 = - C_{10}$ solution to $b \to s \ell^+ \ell^-$ data and does not lead to proton decay at any order in perturbation theory.

### Other

Other possible models besides leptoquarks (above) which have been proposed as possible explanations of the apparently observed flavour anomalies include the following:

## Relation to other anomalies

There is possibly a relation between the flavour anomalies an the anomaliesagnetic moment#Anomalies) observed in the anomalous magnetic moment of the electron and/or the muon (e.g. Chiang-Okada 17)

Indeed, leptoquark models preferred by the flavour anomalies are also a candidate explanation of the anomaly seen at over 4$\sigma$ statistical significance in the anomalous magnetic moment of the muon, see there.

## References

### General

Early suggestion to look for relevant channels are due to

• Patrick Koppenburg, Selection of $B_u \to \ell \ell K$ at LHCb and Sensitivity to $R_K$, 2007 (cern:1027442, pdf)

General introduction to the issue is in

• Rodrigo Alonso, Lepton (non-) unversality in (flavor changing) neutral current B decays, Proceedings of FPCP2019 (arXiv:1907.01716)

and for charm quark physics in

Comprehensive overview of the latest world-avereaged results to be found at:

Measurements include

• LHCb collaboration, Differential branching fractions and isospin asymmetries of $B \to K^{(\ast)}\mu^+ \mu^-$ decays, JHEP 06 (2014) 133 (arXiv:1403.8044)

• LHCb collaboration, Test of lepton universality using $B^+\to K^+ \ell^+ \ell^-$ decays, Phys. Rev. Lett. 113, 151601 (2014) (arXiv:1406.6482)

• LHCb collaboration, Angular analysis and differential branching fraction of the decay $B^0_s \to \phi \mu^+ \mu^-$, JHEP09(2015)179 (arXivL1506.08777)

• LHCb collaboration, Differential branching fraction and angular analysis of $\Lambda^0_b \to \Lambda \mu^+ \mu^-$ decays, JHEP 06 (2015) 115; JHEP 09 (2018) 145 (arXiv:1503.07138)

• LHCb collaboration, Test of lepton universality using $B^0\to K^{\ast 0} \ell^+ \ell^-$ decays, JHEP 08 (2017) 055 (arXiv:1705.05802)

• LHCb collaboration, Measurement of the ratio of the $B^0 \to D^{\ast -} \tau^+ \vu_\tau$ and $B^0 \to D^{\ast - \mu^+ \nu_\mu}$ branching fractions using three-prong τ-lepton decays (arXiv:1708.08856)

• Belle collaboration, Measurement of the $\tau$ lepton polarization and $R(D^\ast)$ in the decay $\bar B \to D^\ast \tau^- \bar \nu_\tau$ with one-prong hadronic τ decays at Belle (arXiv:1709.00129)

• Belle collaboration, Measurement of the $D^{\ast -}$ polarization in the decay $B^0 \to D^{\ast -} \tau^+ \nu_\tau$ (arXiv:1903.03102)

• LHCb collaboration, Search for lepton-universality violation in $B^+ \to K^+ \ell^+ \ell^-$ decays (cern:2668514)

• Belle Collaboration, Test of lepton flavor universality in $B \to K^\ast \ell^+ \ell^-$ decays at Belle (arXiv:1904.02440)

• LHCb collaboration, Lepton flavour universality in charged-current $B$ decays (arXiv:1907.01500)

Review includes

Outlook:

Emphasis of non-perturbative effects:

• Ulrich Nierste, Flavour Anomalies: Phenomenology and BSM Interpretations, talk at Planck 2018, Bonn 2018 (pdf)

• Saeed Kamali, New physics in inclusive semileptonic $B$ decays including nonperturbative corrections (arXiv:1811.07393)

Emphasis of higher loop order-effects:

• Andreas Crivellin, Christoph Greub, Dario Müller, Francesco Saturnino, Importance of Loop Effects in Explaining the Accumulated Evidence for New Physics in B Decays with a Vector Leptoquark, Phys. Rev. Lett. 122, 011805 (2019) (arXiv:1807.02068)

Emphasis of effects of hadronic form factors:

• Sébastien Descotes-Genon, Alexander Khodjamirian, Javier Virto, Light-Cone Sum Rules for $B \to K \pi$ Form Factors and Applications to Rare Decays (arXiv:1908.02267)

• Sebastien Descotes-Genon, Light-cone sum rules for $B \to K \pi$ form factorsand applications to rare decays, talk at bsll2019 (pdf, pdf)

Original articles include:

• Guido D’Amico, Marco Nardecchia, Paolo Panci, Francesco Sannino, Alessandro Strumia, Riccardo Torre, Alfredo Urbano,

Flavour anomalies after the $R_{K^\ast}$ measurement,

J. High Energ. Phys. (2017) 2017 (arXiv:1704.05438)

• Andrea Mauri, Nicola Serra, Rafael Silva Coutinho, Towards establishing Lepton Flavour Universality violation in $\bar B \to \bar K^\ast \ell^+ \ell^-$ decays (arXiv:1805.06401)

• Bernat Capdevila, Andreas Crivellin, Sébastien Descotes-Genon, Joaquim Matias, Javier Virto, Patterns of New Physics in $b \to s \ell^+ \ell^-$ transitions in the light of recent data, JHEP 1801 (2018) 093 (arXiv:1704.05340)

• Alejandro Celis, Javier Fuentes-Martin, Avelino Vicente, Javier Virto, Gauge-invariant implications of the LHCb measurements on Lepton-Flavour Non-Universality, Phys. Rev. D 96, 035026 (2017) (arXiv:1704.05672)

• Monika Blanke, Andreas Crivellin, Stefan de Boer, Teppei Kitahara, Marta Moscati, Ulrich Nierste, Ivan Nišandžić, Impact of polarization observables and $B_c \to \tau \nu$ on new physics explanations of the $b \to c \tau \nu$ anomaly (arXiv:1811.09603)

• Monika Blanke, Andreas Crivellin, Stefan de Boer, Teppei Kitahara, Marta Moscati, Ulrich Nierste, Ivan Nišandžić, Addendum: “Impact of polarization observables and $B_c \to \tau \nu$ on new physics explanations of the $b \to c \tau \nu$ anomaly” (arXiv:1905.08253)

• Jacky Kumar, David London, New physics in $b \to s e^+ e^-$?, Phys. Rev. D 99, 073008 (2019) (arXiv:1901.04516, doi:10.1103/PhysRevD.99.073008)

• Domagoj Leljak, Blazenka Melic, Monalisa Patra, On lepton flavour universality in semileptonic $B_c \to \eta_c, J/\psi$ decays (arXiv:1901.08368)

• Rui-Xiang Shi, Li-Sheng Geng, Benjamín Grinstein, Sebastian Jäger, Jorge Martin Camalich, Revisiting the new-physics interpretation of the $b \to c \tau \nu$ data (arXiv:1905.08498)

Cautionary remarks include

In contrast, an argument that the threshold statistical significance for flavour anomalies should be taken to be $3\sigma$ instead of $5 \sigma$ is made in

### Possible explanations/models

#### General EFT parameterization

• T. Hurth, A. Arbey, F. Mahmoudi, S. Neshatpour, New global fits to $b \to s$ data with all relevant parameters, Proceedings of the Seventh Workshop on Theory, Phenomenology and Experiments in Flavour Physics, Capri, 8-10 June 2018 (arXiv:1812.07602)

• Srimoy Bhattacharya, Aritra Biswas, Zaineb Calcuttawala, Sunando Kumar Patra, An in-depth analysis of $b \to c(s)$ semileptonic observables with possible $\mu \to \tau$ mixing (arXiv:1902.02796)

• Marcel Algueró, Bernat Capdevila, Sébastien Descotes-Genon, Pere Masjuan, Joaquim Matias, What $R_K$ and $Q_5$ can tell us about New Physics in $b \to s \ell \ell$ transitions? (arXiv:1902.04900)

• Marcel Algueró, Bernat Capdevila, Andreas Crivellin, Sébastien Descotes-Genon, Pere Masjuan, Joaquim Matias, Javier Virto, Addendum: “Patterns of New Physics in $b \to s \ell^+ \ell^-$ transitions in the light of recent data” (arXiv:1903.09578)

• Ashutosh Kumar Alok, Amol Dighe, Shireen Gangal, Dinesh Kumar, Continuing search for new physics in $b \to \mu s s$ decays: two operators at a time (arXiv:1903.09617)

• Marco Ciuchini, António M. Coutinho, Marco Fedele, Enrico Franco, Ayan Paul, Luca Silvestrini, Mauro Valli, New Physics in $b \to s \ell^+ \ell^-$ confronts new data on Lepton Universality (arXiv:1903.09632)

• Jason Aebischer, Wolfgang Altmannshofer, Diego Guadagnoli, Meril Reboud, Peter Stangl, David M. Straub, B-decay discrepancies after Moriond 2019 (arXiv:1903.10434)

• Alakabha Datta, Jacky Kumar, David London, The $B$ Anomalies and New Physics in $b \to s e^+ e^-$ (arXiv:1903.10086)

• Ashutosh Kumar Alok, Dinesh Kumar, Suman Kumbhakar, S Uma Sankar, Impact of $D^\ast$ polarization measurement on solutions to $R_D$-$R_{D^\ast}$ anomalies (arXiv:1903.10486)

• Pere Arnan, Andreas Crivellin, Marco Fedele, Federico Mescia, Generic Loop Effects of New Scalars and Fermions in $b \to s \ell^+ \ell^-$ and a Vector-like 4th Generation (arXiv:1904.05890)

• A. Arbey, T. Hurth, F. Mahmoudi, D. Martinez Santos, S. Neshatpour, Update on the $b \to s$ anomalies (arXiv:1904.08399)

• Pouya Asadi, David Shih, Maximizing the Impact of New Physics in $b \to c \tau \nu$ Anomalies, (arXiv:1905.03311)

• J. E. Chavez-Saab, Marxil Sánchez, Genaro Toledo, $R_{D^\ast}$ or $R_{D_\pi}$: closing the theoretical gap? (arXiv:1905.03394)

• Suman Kumbhakar, Ashutosh Kumar Alok, Dinesh Kumar, S Uma Sankar, Resolving $R_D$ and $R_{D^\ast}$ anomalies (arXiv:1905.03513)

• Jyoti Saini, Dinesh Kumar, Shireen Gangal, S. B. Dasm, Probing signatures of beyond standard model physics through $B_s^\ast \to \mu^+ \mu^-$ decay (arXiv:1905.03933)

• David London, CP Violation in $\bar B^0 \to D^{\ast +} \ell^- \bar \nu_\ell$ (arXiv:1906.07752)

• Marta Moscati, New Physics in $b \to c \tau \nu$: Impact of Polarisation Observables and $B_c \to \tau \nu$ (arXiv:1906.08035)

• Damir Becirevic, Marco Fedele, Ivan Nisandzic, Andrey Tayduganov, Lepton Flavor Universality tests through angular observables of $\bar B \to D^{(\ast) \ell \bar \nu}$ decay modes (arXiv:1907.02257)

#### Leptoquarks

explanation via assumption of leptoquarks:

• Martin Bauer, Matthias Neubert, One Leptoquark to Rule Them All: A Minimal Explanation for $R_{D^{(\ast)}}$, $R_K$ and $(g-2)_\mu$, Phys. Rev. Lett. 116, 141802 (2016) (arXiv:1511.01900)

• Yi Cai, John Gargalionis, Michael A. Schmidt, Raymond R. Volkas, Reconsidering the One Leptoquark solution: flavor anomalies and neutrino mass (arXiv:1704.05849)

• Estefania Coluccio Leskow, Andreas Crivellin, Giancarlo D’Ambrosio, Dario Müller, $(g-2)_\mu$, Lepton Flavour Violation and Z Decays with Leptoquarks: Correlations and Future Prospects, Phys. Rev. D 95, 055018 (2017) (arXiv:1612.06858)

• Andreas Crivellin, New Physics in Flavour Observables (arXiv:1706.00929)

• Adam Falkowski, Leptoquarks strike back, November 2017

• Dario Müller, Leptoquarks in Flavour Physics, EPJ Web of Conferences 179, 01015 (2018) (arXiv:1801.03380)

• Shinya Matsuzaki, Kenji Nishiwaki, Kei Yamamoto, Simultaneous interpretation of K and B anomalies in terms of chiral-flavorful vectors (arXiv:1806.02312)

• Angelo Monteux, Arvind Rajaraman, B Anomalies and Leptoquarks at the LHC: Beyond the Lepton-Quark Final State, Phys. Rev. D 98, 115032 (2018) (arXiv:1803.05962)

• Ufuk Aydemir, Djordje Minic, Chen Sun, Tatsu Takeuchi, $B$-decay anomalies and scalar leptoquarks in unified Pati-Salam models from noncommutative geometry, JHEP 09 (2018) 117 (arXiv:1804.05844)

• Damir Bečirević, Ilja Doršner, Svjetlana Fajfer, Nejc Košnik, Darius A. Faroughy, Olcyr Sumensari, Scalar leptoquarks from GUT to accommodate the $B$-physics anomalies, Phys. Rev. D 98, 055003 (2018) (arXiv:1806.05689)

• Jacky Kumar, David London, Ryoutaro Watanabe, Combined Explanations of the $b \to s \mu^+ \mu^-$ and $b \to c \tau^- \bar \nu$ Anomalies: a General Model Analysis, Phys. Rev. D 99, 015007 (2019) (arXiv:1806.07403)

(reviewed in Kumar 19)

• Tanumoy Mandal, Subhadip Mitra, Swapnil Raz, $R_{D^{(\ast)}}$ in minimal leptoquark scenarios: impact of interference on the exclusion limits from LHC data (arXiv:1811.03561)

• Jason Aebischer, Andreas Crivellin, Christoph Greub, QCD Improved Matching for Semi-Leptonic B Decays with Leptoquarks (arXiv:1811.08907)

• Michael J. Baker, Javier Fuentes-Martin, Gino Isidori, Matthias König, High-pT Signatures in Vector-Leptoquark Models (arXiv:1901.10480)

• Ivo de Medeiros Varzielas, Jim Talbert, Simplified Models of Flavourful Leptoquarks (arXiv:1901.10484)

• Natascia Vignaroli, Seeking leptoquarks in the $t \bar t$ plus missing energy channel at the high-luminosity LHC (arXiv:1808.10309)

• Ufuk Aydemir, Tanumoy Mandal, Subhadip Mitra, A single TeV-scale scalar leptoquark in SO(10) grand unification and B-decay anomalies (arXiv:1902.08108)

• Ivo de Medeiros Varzielas, Stephen F. King, Origin of Yukawa couplings for Higgs and leptoquarks (arXiv:1902.09266)

• Oscar Cata, Thomas Mannel, Linking lepton number violation with $B$ anomalies (arXiv:1903.01799)

• Bhubanjyoti Bhattacharya, Alakabha Datta, Saeed Kamali, David London, CP Violation in $\bar B^0 \to D^{\ast +} \mu^- \bar \nu_\mu$ (arXiv:1903.02567)

• Han Yan, Ya-Dong Yang, Xing-Bo Yuan, Phenomenology of $b \to c \tau \bar \nu$ decays in a scalar leptoquark model (arXiv:1905.01795)

• Alakabha Datta, Divya Sachdeva, John Waite, A unified explanation of $b \to s\mu^= \mu^-$ anomalies, neutrino masses and $B \to \pi K$ puzzle (arXiv:1905.04046)

• Andrei Angelescu, Single Leptoquark Solutions to the $B$-physics Anomalies, contribution to the 2019 EW session of the 54th Rencontres de Moriond (arXiv:1905.06044)

• Oleg Popov, Michael A. Schmidt, Graham White, $R_2$ as a single leptoquark solution to $R_{D^{(\ast)}}$ and $R_{K^{(\ast)}}$ (arXiv:1905.06339)

• Andreas Crivellin, Francesco Saturnino, Explaining the Flavor Anomalies with a Vector Leptoquark (Moriond 2019 update) (arXiv:1906.01222)

• Michal Malinský, Lepton non-universality in $B$-decays in the minimal leptoquark gauge model (arXiv:1906.09174)

• Jordan Bernigaud, Ivo de Medeiros Varzielas, Jim Talbert, Finite Family Groups for Fermionic and Leptoquark Mixing Patterns (arXiv:1906.11270)

• Junichiro Kawamura, Stuart Raby, Andreas Trautner, Complete Vector-like Fourth Family and new $U(1)'$ for Muon Anomalies (arXiv:1906.11297)

• Leandro Da Rold, Federico Lamagna, A vector leptoquark for the B-physics anomalies from a composite GUT (arXiv:1906.11666)

• Jacky Kumar, Combined explanation of the B-anomalies, Proceedings for FPCP 2019 (arXiv:1907.00416)

(review of KumarLondonWatanabe18)

• C. Hati, J. Kriewald, J. Orloff, A.M. Teixeira, A nonunitary interpretation for a single vector leptoquark combined explanation to the B-decay anomalies (arXiv:1907.05511)

leptoquarks within a Randall-Sundrum model:

• Andreas Crivellin, Explaining the Flavour Anomalies with the Pati-Salam Vector Leptoquark, PoS LHCP2018 (2018) 269 (spire:1713260, doi:10.22323/1.321.0269)

• Monika Blanke, Andreas Crivellin, $B$ Meson Anomalies in a Pati-Salam Model within the Randall-Sundrum Background, Phys. Rev. Lett. 121, 011801 (2018) (arXiv:1801.07256)

• Andreas Crivellin, Francesco Saturnino, Correlating Tauonic B Decays to the Neutron EDM via a Scalar Leptoquark (arXiv:1905.08257)

• Innes Bigaran, John Gargalionis, Raymond R. Volkas, A near-minimal leptoquark model for reconciling flavour anomalies and generating radiative neutrino masses (arXiv:1906.01870)

leptoquarks particularly as fields in a grand unified theory:

• Julian Heeck, Daniele Teresi, Pati-Salam explanations of the B-meson anomalies, JHEP 12 (2018) 103 (arXiv:1808.07492)

• Julian Heeck, Daniele Teresi, Pati-Salam and lepton universality in B decays (arXiv:1905.05211)

and in relation to axions:

• Javier Fuentes-Martin, Mario Reig, Avelino Vicente, 4321… axion! (arXiv:1907.02550)

leptoquarks as possible explanation also of the anomalies seen in the ANITA experiment

• Bhavesh Chauhan, Subhendra Mohanty, A common leptoquark solution of flavor and ANITA anomalies (arXiv:1812.00919)

#### $Z'$-boson

explanations via assumption of Z'-bosons:

• Rhorry Gauld, Florian Goertz, Ulrich Haisch, An explicit Z’-boson explanation of the $B \to K^\ast \mu^+ \mu^-$ anomaly, JHEP01(2014)069 (arXiv:1310.1082)

• G. D’Ambrosio, A. M. Iyer, F. Piccinini, A.D. Polosa, Confronting $B$ anomalies with atomic physics (arXiv:1902.00893)

• P. Ko, Takaaki Nomura, Chaehyun Yu, $b \to s \mu^+ \mu^-$ anomalies and related phenomenology in $U(1)_{B_{3-x_\mu L_\mu - x_\tau L_\tau}}$ flavor gauge models (arXiv:1902.06107)

• Joe Davighi, Connecting neutral current $B$ anomalies with the heaviness of the third family, Contribution to the 2019 QCD session of the 54th Rencontres de Moriond (arXiv:1905.06073)

• Wolfgang Altmannshofer, Joe Davighi, Marco Nardecchia, Gauging the accidental symmetries of the Standard Model, and implications for the flavour anomalies (arXiv:1909.02021)

#### Other

• David Marzocca, Addressing the B-physics anomalies in a fundamental Composite Higgs Model, JHEP07(2018)121 (arXiv:1803.10972)

• Andreas Crivellin, Dario Müller, Christoph Wiegand, $b \to s \ell^+ \ell^-$ Transitions in Two-Higgs-Doublet Models (arXiv:1903.10440)

• Peter Stangl, Flavour anomalies and (fundamental) partial compositeness (arXiv:1907.05158)

• Seungwon Baek, Scalar dark matter behind $b \to s \mu \mu$ anomaly (arXiv:1901.04761)

• D.G. Cerdeno, A. Cheek, P. Martin-Ramiro, J.M. Moreno, B anomalies and dark matter: a complex connection (arXiv:1902.01789)

• Anirban Biswas, Avirup Shaw, Reconciling dark matter, $R_{K^{(\ast)}}$ anomalies and $(g-2)_\mu$ in an $L_\mu-L_\tau$ scenario (arXiv:1903.08745)

• Carlo Marzo, Luca Marzola, Martti Raidal, Common explanation to the $R_{K^{(\ast)}}$, $R_{K^{(\ast)}}$ and $\epsilon'/\epsilon$ anomalies in a 3HDM+$\nu_R$ and connections to neutrino physics (arXiv:1901.08290)

• Luigi Delle Rose, Shaaban Khalil, Simon J.D. King, Stefano Moretti, $R_K$ and $R_{K^\ast}$ in an Aligned 2HDM with Right-Handed Neutrinos (arXiv:1903.11146)

MSSM with R-parity-violation

• Dong-Yang Wang, Ya-Dong Yang, Xing-Bo Yuan, $b \to c \tau \bar \nu$ decays in supersymmetry with R-parity violation (arXiv:1905.08784)
• Jong-Phil Lee, $B$ anomalies in the nonminimal universal extra dimension model (arXiv:1906.07345)

Joint explanation with the anomalies observed in the muon anomalous magnetic moment:

• Cheng-Wei Chiang, Hiroshi Okada, A simple model for explaining muon-related anomalies and dark matter (arXiv:1711.07365)

• Junichiro Kawamura, Stuart Raby, Andreas Trautner, Complete Vector-like Fourth Family and new $U(1)'$ for Muon Anomalies (arXiv:1906.11297)

Exotic Higgs field couplings to a hidden sector:

Last revised on October 18, 2019 at 08:44:32. See the history of this page for a list of all contributions to it.