A general effective field theory description of $b \to s l^+ l^-$ lepton universality ratios

We present an up-to-date complete model-independent global fit to $$b\rightarrow s\ell \ell $$ b → s ℓ ℓ observables that confirms patterns of New Physics able to explain the data. We include the recent LHCb measurements of $$R_K$$ R K , $$R_{K_S}$$ R K S , $$R_{K^{*+}}$$ R K ∗ + , $$B_s \rightarrow \phi \mu ^+\mu ^-$$ B s → ϕ μ + μ - and $$B_s\rightarrow \mu ^+\mu ^-$$ B s → μ + μ - in our analysis, which now includes 254 observables. This updates our previous analyses and strengthens their two main outcomes. First, the presence of right-handed couplings encoded in the Wilson coefficients $${{\mathcal {C}}}_{9'\mu }$$ C 9 ′ μ and $${{\mathcal {C}}}_{10'\mu }$$ C 10 ′ μ remains a viable possibility. Second, a lepton flavour universality violating (LFUV) left-handed lepton coupling ($${{\mathcal {C}}}_{9\mu }^{\mathrm{V}}=-{{\mathcal {C}}}_{10\mu }^{\mathrm{V}}$$ C 9 μ V = - C 10 μ V ), often preferred from the model building point of view, accommodates the data better if lepton-flavour universal New Physics is allowed, in particular in $${{\mathcal {C}}}_{9}^{\mathrm{U}}$$ C 9 U . We observe that the LFUV observable $$Q_5$$ Q 5 offers a very interesting possibility to separate both types of scenarios.

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“…This issue has been recently discussed in Refs. [62,63] (see also earlier discussions on this topic in Refs. [44,64]).…”

Section: Fit Approachmentioning

confidence: 93%

$$b\rightarrow s\ell ^+\ell ^-$$ global fits after $$R_{K_S}$$ and $$R_{K^{*+}}$$

et al. 2022

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“…Meanwhile, there are also puzzles in the angular distributions of B → K * µ + µ − decays in the low-q 2 region. These anomalies point to potential contributions of new physics in b → s + − transitions [690][691][692][693][694][695][696][697][698][699]. Particularly, new physics scenarios that mainly affect b → sµ + µ − transitions are preferred, according to global analysis in the framework of SM effective field theory [692-695, 698, 699].…”

Section: Lhcb 3fbmentioning

confidence: 99%

Heavy Flavour Physics and CP Violation at LHCb: a Ten-Year Review

Chen¹,

Li²,

Qian³

et al. 2021

Preprint

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Heavy flavour physics provides excellent opportunities to indirectly search for new physics at very high energy scales and to study hadron properties for deep understanding of the strong interaction. The LHCb experiment has been playing a leading role in the study of heavy flavour physics since the start of the LHC operations about ten years ago, and made a range of high-precision measurements and unexpected discoveries, which may have far-reaching implications on the field of particle physics. This review highlights a selection of the most influential physics results on CP violation, rare decays, and heavy flavour production and spectroscopy obtained by LHCb using the data collected during the first two operation periods of the LHC. The upgrade plan of LHCb and the physics prospects are also briefly discussed.

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“…These new measurements have attracted much attention and led to many model-independent global analyses [14,[24][25][26][27][28][29][30][31][32][33][34][35][36] assuming the presence of NP only in the mode, and it is shown that the significance of the SM exclusion in the global fits is about . These data have also been explained in NP models involving tree-level exchanges of new particles such as the neutral gauge boson [37][38][39][40][41][42][43][44][45][46], leptoquarks [31,33,34,[47][48][49][50][51][52][53][54][55][56][57] or scalar Higgs [58,59].…”

Section: Introduction B → Sℓℓmentioning

confidence: 99%

Discriminating 1D new physics solutions in b → sℓℓ decays *

Li¹,

Shi²,

Geng

2022

Chinese Phys. C

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The recent measurements of $R_{K^+}$, $R_{K_S^0}$, $R_{K^{*+}}$, $B_s\to\mu^+\mu^-$, a set of CP-averaged angular observables for the $B^0\to K^{*0}\mu^+\mu^-$ decay, and its isospin partner $B^+\to K^{*+}\mu^+\mu^-$ by the LHCb Collaboration, consistently hint at lepton universality violation in the $b\to s\ell\ell$ transitions. In this work, we first perform global fits to the $b\to s\ell\ell$ data and show that five one-dimensional scenarios, i.e, $\delta C_9^{\mu}$, $\delta C_{10}^{\mu}$, $\delta C_L^{\mu}$, $\delta C_9^{\mu}=C_{10}^{\mu\prime}$, and $\delta C_9^{\mu}=-C_9^{\mu\prime}$ can best explain the so-called B anamolies. Furthermore, we explore how these scenarios can be distinguished from each other. For this purpose, we first study the combinations of four angular asymmetries $A_i$~$(i=3,4,5,9)$ and find that they cannot distinguish the five new physics scenarios. We then show that a newly constructed ratio $R_{S}$ can uniquely discriminate the five new physics scenarios in proper intervals of $q^2$ if it can be measured with a percent level precision. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

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A general effective field theory description of $b \to s l^+ l^-$ lepton universality ratios

Cited by 3 publications

References 31 publications

$$b\rightarrow s\ell ^+\ell ^-$$ global fits after $$R_{K_S}$$ and $$R_{K^{*+}}$$

$$b\rightarrow s\ell ^+\ell ^-$$ global fits after $$R_{K_S}$$ and $$R_{K^{*+}}$$

Heavy Flavour Physics and CP Violation at LHCb: a Ten-Year Review

Discriminating 1D new physics solutions in b → sℓℓ decays *

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