### Conveners

#### Flavour physics - CKM and beyond

- jorge Martin Camalich (Instituto de Astrofísica de Canarias)
- Mat Charles (Sorbonne Université / LPNHE)
- Nuno Leonardo (LIP)

#### Flavour physics - CKM and beyond

- Nuno Leonardo (LIP)
- Mat Charles (Sorbonne Université / LPNHE)
- jorge Martin Camalich (Instituto de Astrofísica de Canarias)

[This talk is a combination of several submitted abstracts, including the following.]

In the recent years, several measurements of $B$-decays with flavor changing neutral currents, i.e. $b\to s$ transitions hint at deviations from the Standard Model (SM) predictions. These decays are forbidden at tree-level in the SM and can only proceed via suppressed loop level or box diagrams. Rare...

In the Standard Model (SM), the $b \to s$ and $b \to d$ flavor-changing neutral currents (FCNC) are induced by loop effects. Rare semileptonic $B$-meson decays originated by these currents are standard channels for testing the SM precisely and searching for possible physics beyond the Standard Model. Differential branching fractions of semileptonic $B$-decays and angular distributions in some...

BESIII has collected 2.9 and 6.3 fb-1 of e+e- collision data samples at 3.773 and 4.178-4.226 GeV, respectively. We report recent measurements of the (semi)leptonic decays D(s) -> l+nu (l=mu, tau) and D(s) -> X l+nu [X=K(*), rho, eta('), a_0, K_1, and l=e, mu]. The decay constants f_D(s), the semileptonic form factors f(0) and the CKM matrix elements |V_cs(d)| are determined precisely. These...

Recent years have seen a series of anomalies hinting at lepton universality violation in B-meson decays, which can be explained with a single TeV-scale Pati-Salam leptoquark mediator found in "4321" models. The tension of the muon (g-2) measurement, as recently confirmed at Fermilab, with SM prediction can, however, not be explained with the same mediator. We explore how to explain the muon...

The ATLAS and CMS experiments have performed measurements of B-meson rare decays proceeding via suppressed electroweak flavour changing neutral currents.

This talk will focus on the latest results from the ATLAS and CMS on B^0_s → mu mu, B^0 → mu mu, B^0 → K^*0 mu mu and B^+ → K^(*)+ mu mu decays. The LHC combined results on the B decays to two muons will also be presented.

In this talk, we will present the status of lepton flavor physics in composite Higgs models with partial compositeness in the light of recent data in the lepton sector. We will consider anarchic flavor setups, scenarios with flavor symmetries, and minimal incarnations of the see-saw mechanism that naturally predict non-negligible lepton compositeness.

The focus will be on lepton flavor...

Flavour physics with rare, electroweak-penguin, and semileptonic decays at LHCb

Many new physics scenarios contain ultralight scalars, states which are either exactly massless or much lighter than any other massive particle in the model. Axions and majorons constitute well-motivated examples of this type of particle. In this work, we explore the phenomenology of these states in low-energy leptonic observables. After adopting a model independent approach that includes both...

CKM, CPV and mixing results at LHCb

Four-quark operators mediate non-leptonic kaon decays and play an important role in inclusive QCD observables. Using their symmetry transformations and the known properties of QCD at low energies, we re-derive and extend generic relations among matrix elements and study their phenomenological implications. They include a determination of the electroweak-penguin contributions to eps'/eps based...

The recent CPV measurements from ATLAS and CMS with B0s to J/psi Phi decays will be discussed together with some recent results concerning Heavy Flavour production from both experiments.

[This talk is a combination of several submitted abstracts, including the following.]

In the Belle II experiment, we have accumulated integrated luminosity of more than 100 fb$^{-1}$ after starting the physics data taking in 2019. It is comparable to the data sets used for the $B^0$ lifetime $\tau_{B^0}$ and mixing $\Delta m_d$ measurements in the BABAR and Belle. To demonstrate high...

Particularly interesting processes to test the Standard Model are non-leptonic $B^0_s \rightarrow D_s^{\pm} K^{\mp}$ transitions. As these decays occur via pure tree diagrams, they allow a theoretically clean determination of the angle $\gamma$ of the unitarity triangle. Considering recent LHCb results, an intriguing picture arises, showing tension with the Standard Model. Utilising the...

BESIII has collected 2.9, 6.3 and 4.4 fb-1 of e+e- collision data samples at 3.773, 4.178-4.226 and 4.6-4.7 GeV, respectively. We report recent measurements of strong phase differences in D0 and D0-bar decays of KSpi+pi-, KSK+K-, K-pi+pi+pi- and K-pi+pi0. The obtained parameters are important to reduce the systematic uncertainty in the gamma/phi_3 measurement at LHCb and Belle II. We will...

The J-PARC E36 experiment is aiming at searching for the lepton universality violation by precisely measuring the ratio of the branching ratio of the $K^+ \rightarrow e^+ \nu$ ($K_{e2}$) to $K^+ \rightarrow \mu^+ \nu$ ($K_{\mu 2}$) decays. The E36 experiment was performed at J-PARC employing a stopped $K^+$ beam in conjunction with a 12-sector iron-core superconducting toroidal spectrometer....

The first row of the Cabibbo-Cobayashi-Maskawa (CKM) matrix shows a discrepancy of ~$3\sigma$ with unitarity, known as the ”Cabibbo Angle Anomaly” (CAA). After reviewing the origin and status of the anomaly, I investigate the various possibilities to explain it in the context of physics beyond Standard Model (BSM) which can be broadly grouped into three categories: modifications of...

The systematic effect associated to the finite-volume constraint in lattice calculations has to be corrected for in order to make physical predictions and from these precision tests of the Standard Model. For (sub-)per cent precision one has to include also electromagnetic effects on the lattice, which can lead to particularly large finite-size effects. The finite-size scaling depends not only...

The NA62 experiment at CERN reports searches for K+ → e+N, K+→μ+N and K+→μ+νX decays, where N and X are massive invisible particles, using the 2016-2018 data set.

The N particle is assumed to be a heavy neutral lepton, and the results are expressed as upper limits of O(10−9) and O(10−8) of the neutrino mixing parameter |Ue4|2 and |Uμ4|2, improving on the earlier searches for heavy neutral...

Applying an operator product expansion approach an updated Standard Model prediction of the $B_c$ lifetime is presented. The non-perturbative velocity expansion is carried out up to third order in the relative velocity of the heavy quarks. The scheme dependence is studied using three different mass schemes for the $\bar b$ and $c$ quarks, resulting in three different values consistent with...

Flavour physics will play a role of paramount importance also in the foreseen upgrades and developments of the LHC experiments. Run3 and then high-luminosity LHC will allow the ATLAS and CMS experiments to provide results with improved precisions and with an increased sensitivity to new physics scenarios. The talk will provide an overview of expected ATLAS and CMS performances on this topic.

Flavour prospects with the LHCb upgrades