Search

Kaon physics is at an important experimental juncture with respect to the ongoing measurements of several observables. This work will build on the existing status by formulating different phenomenological analyses corresponding to different paths that may lie ahead. Beginning with the golden channels, $K^\rightarrow\pi^\nu\bar\nu$ and $K_L\rightarrow\pi^0\nu\bar\nu$, the paper will eventually cast the spotlight on the importance of a precise measurement of BR($K_L\rightarrow\pi^0\ell\bar\ell$). The phenomenological analyses involve sequentially adding kaon physics observables at the projected final precision of their respective measurements to the global fit. More specifically, we consider three different scenarios with different sets of observables assumed at their final precisions. Beginning with BR($K^\rightarrow\pi^\nu\bar\nu$) and BR($K_L\rightarrow\pi^0\nu\bar\nu$), we sequentially add BR($K_L\rightarrow\pi^0 e\bar e$) and BR($K_L\rightarrow\pi^0 \mu\bar\mu$) to the global fit. The evolution of the result from one scenario to the next makes a strong case for the consideration of future measurement of R($K_L\rightarrow\pi^0\ell\bar\ell$)., Comment: 14 pages, 4 figures, 1 table

The search for New Physics (NP) beyond the Standard Model (SM) has been a central focus of particle physics, including in the context of $B$-meson decays involving $b \to s \ell \ell$ transitions. These transitions, mediated by flavour-changing neutral currents, are highly sensitive to small NP effects due to their suppression in the SM. While direct searches at colliders have not yet led to NP discoveries, indirect probes through semi-leptonic decays have revealed anomalies in observables such as the branching fraction $\mathcal{B}(B \to K \mu \mu)$ and the angular observable $P_5'(B \to K^* \mu \mu)$. In order to assess the observed tensions, it is essential to ensure an accurate SM prediction. In this review, we examine the theoretical basis of the $B \to K^{(*)} \ell \ell$ decays, addressing in particular key uncertainties arising from local and non-local form factors. We also discuss the impact of QED corrections to the Wilson coefficients, as well as the effect of CKM matrix elements on the predictions and the tension with the experimental measurements. We discuss the most recent results, highlighting ongoing efforts to refine predictions and to constrain potential signs of NP in these critical decay processes., Comment: 29 pages, 4 figures, 3 tables. Contribution to the "Symmetry" Special Issue "Symmetries and Anomalies in Flavour Physics"

The rare kaon decay $K^+ \to \pi^+\ell^+\ell^-$ offers insights into Standard Model (SM) physics and beyond. Driven by vector form factor in the SM, it can also probe non-standard contributions. In this letter we study the scalar contribution, $f_S$. Using differential decay width and Forward-Backward Asymmetry we propose a simultaneous fit to vector and scalar contributions which is necessary for a consistent analysis. Novel bounds on $|f_S|$ are presented for the first time through a reinterpretation of the E865, NA48/2, and NA62 experimental results. The analysis results in the most precise bound $f_S < 7.9\times 10^{-6}$ at 90$\%$ confidence level., Comment: References added, Improved discussion of the results. 9 pages, 2 Tables, 1 Figure

This work addresses the calculation of local form factors involved in the theoretical predictions of semileptonic $B$-meson decays at low-$q^2$. We present a new approach to the method of QCD Light-Cone Sum Rule with $B-$meson Light-Cone Distribution Amplitudes. In our strategy, we bypass the semi-global quark-hadron duality (QHD) approximation which usually contributes an unknown and potentially large systematic error to the prediction of form factors. We trade this improvement for an increased reliance on higher-order contributions in perturbation theory. Unlike the systematic error from semi-global QHD, truncation errors are assessable and systematically improvable, hence allowing robust predictions of form factors. For the transitions $B\to \pi,\rho,K^{(*)}$, our predictions agree with the literature for all form factors at $q^2=0$., Comment: 35 pages, 6 figures, 7 tables

We derive a low-temperature expansion of the formula to compute the average annihilation rate $\langle \sigma v \rangle$ for dark matter in $\mathbb{Z}_2$-symmetric models, both in the absence and the presence of mass degeneracy in the spectrum near the dark matter candidate. We show that the result obtained in the absence of mass degeneracy is compatible with the analytic formulae in the literature, and that it has a better numerical behaviour for low temperatures. We also provide as ancillary files two Wolfram Mathematica notebooks which perform the two expansions at any order.

Rare kaon decays offer a powerful tool for investigating new physics in $s\to d$ transitions. Currently, many of the interesting decay modes are either measured with rather large uncertainties compared to their theoretical predictions or have not yet been observed. The future HIKE programme at CERN will provide unprecedented sensitivity to rare kaon decays, allowing for strong constraints on new physics scenarios with lepton flavour universality violation. We present the overall picture that emerges from a study of the different decay modes with a global analysis considering projections based on the HIKE programme, both with and without KOTO-II future measurements. We also highlight the most relevant decays and identify that in addition to the "golden channel", $K^+\to\pi^+\nu\bar\nu$, the rare $K_L\to\pi^0 \ell\bar\ell$ decay, especially in the electron sector offers strong constraints on short-distance physics., Comment: 16 pages, 5 figures

Kaon physics is at a turning point -- while the rare-kaon experiments NA62 and KOTO are in full swing, the end of their lifetime is approaching and the future experimental landscape needs to be defined. With HIKE, KOTO-II and LHCb-Phase-II on the table and under scrutiny, it is a very good moment in time to take stock and contemplate about the opportunities these experiments and theoretical developments provide for particle physics in the coming decade and beyond. This paper provides a compact summary of talks and discussions from the Kaons@CERN 2023 workshop., Comment: 55 pages, Summary of Kaons@CERN 23 workshop, references updated, typos fixed, version as published in EPJC

The Experimental Cavern North 3 (ECN3) is an underground experimental cavern on the CERN Pr\'evessin site. ECN3 currently hosts the NA62 experiment, with a physics programme devoted to rare kaon decays and searches of hidden particles approved until Long Shutdown 3 (LS3). Several options are proposed on the longer term in order to make best use of the worldwide unique potential of the high-intensity/high-energy proton beam extracted from the Super Proton Synchrotron (SPS) in ECN3. The current status of their study by the CERN Physics Beyond Colliders (PBC) Study Group is presented, including considerations on beam requirements and upgrades, detector R&D and construction, schedules and cost, as well as physics potential within the CERN and worldwide landscape., Comment: 113 pages, 39 figures

We discuss the status of $b \to s \ell^+\ell^-$ decays in the post-$R_{K^{(*)}}$ era. The recent LHCb update of $R_K$ and $R_{K^*}$ measurements which are now compatible with the Standard Model, constrain new physics contributions to be lepton flavor universal, allowing only small deviations from this limit. Besides the latest LHCb measurements of $R_K$ and $R_{K^{*}}$, we also include the recent CMS measurements of $R_K$ and of the branching ratio of $B^+ \to K^+ \mu^+\mu^-$. We present a model-independent analysis of the $b\to s \ell^+ \ell^-$ data and investigate the implications of the different sets of observables. In addition, we consider multi-dimensional fits and discuss the significance of more complex new physics scenarios compared to one- and two-dimensional scenarios., Comment: 13 pages, 3 figures

We present here a new package to automatically generate a complete library of 2 to 2 squared amplitudes at leading order in any New Physics models. The package is written in C++ and based on the MARTY software. The numerical library generated allows for the computation of relic density by embedding the algorithms of SuperIso Relic., Comment: 27 pages, 8 figures. DarkPACK can be obtained from https://gitlab.in2p3.fr/darkpack/darkpack-public

We discuss the implications of $b \to s \ell^+\ell^-$ measurements and their deviations with respect to the Standard Model predictions in a model-independent framework. We highlight in particular the impact of the recent updated measurements including the updated $B_s \to \phi \mu^+\mu^-$ branching ratios and angular observables, the recent CMS measurement of the branching ratio of $B_s\to\mu^+ \mu^-$, and the LHCb measured lepton flavour universality violating ratios $R_{K_S^0}$ and $R_{K^{*+}}$. In addition, we check the compatibility of the new physics effect for the theoretically clean observables with the rest of the neutral $B$ decays observables., Comment: 12 pages, 4 figures. Based on talks given by S.N. at FPCapri2022 and by F.M. at FCCP2022

We present an overview of the recent neutral current $B$ decays focusing on the deviations with respect to the Standard Model predictions that are observed in $b \to s \ell^+\ell^-$ transitions, and discuss their implications for new physics scenarios in a model-independent way by means of global statistical fits. The prospects for future discoveries in the individual channels, in particular using the theoretically clean observables are also addressed., Comment: 7 pages, 5 figures, contribution to the proceedings of the "20th Conference on Flavor Physics and CP Violation (FPCP2022)", Oxford, Mississippi, May 2022

We present an overview of SuperIso v4.1 which is a public program for the calculation of flavour physics observables. We give examples of using SuperIso to constrain new physics scenarios with kaon physics and present the implications of rare B-decays., Comment: 9 pages, 3 figures. Contribution to the proceedings of "Computational Tools for High Energy Physics and Cosmology (CompTools2021)", Lyon, France

The kaon sector is characterised by several processes which are under active investigation across different experiments. In this work, we present the global picture that emerges from a study of the different decay modes. We begin by revisiting the theoretical component of these decays and providing up-to-date predictions of the Standard Model as well as the corresponding uncertainties. Several new features emerge, in particular for $K_{S,L}\to \mu\bar\mu$, and are presented in considerable detail. This offers an ideal platform for extracting the parameter space supported by the existing data. Motivated by possible lepton flavour universality violation in $B$ decays, we investigate such Beyond the Standard Model effects also in rare kaon decays. Without loss of generality, our primary analyses correspond to the paradigm where the Wilson coefficients for operators involving tau leptons are chosen to be equal to that involving the muon, i.e. $\delta C^\tau=\delta C^\mu$. We conclude by presenting the possible picture that can be achieved towards the end of the run of data accumulation in the planned experiments. This includes assumptions on possible sensitivity goals that the experiments can aim to achieve, in order to extract the kind of physics highlighted in this paper., Comment: 32 pages, 14 figures. v2: references added

Motivated by tensions between experimental measurements and SM predictions in $b\to s \ell^+\ell^-$ transitions, we present the first study of non-minimal flavour-violating Minimal Supersymmetric Standard Model (MSSM) scenarios contributing to the relevant Wilson coefficients to address the observed anomalies using SuperIso and MARTY. We calculate the full one-loop analytical contributions of the general MSSM to Wilson coefficients relevant for flavour anomalies, together with the anomalous muon magnetic dipole moment $(g-2)_\mu$. We show that, after imposing theoretical constraints on the flavour-violating parameters we can find scenarios in agreement with the experimental measurements that can address at the same time the tensions in flavour observables and in $(g-2)_\mu$., Comment: 34 pages, 12 figures, 5 tables. v2: references added

The study of the Higgs boson properties offers compelling perspectives for testing the effects of physics beyond the Standard Model and has deep implications for the LHC program and future colliders. Accurate determinations of the Higgs boson properties can provide us with a distinctively precise picture of the Higgs sector, set tight bounds, and predict ranges for the values of new physics model parameters. In this paper, we discuss the constraints on supersymmetry that can be derived by a determination of the Higgs boson mass and couplings. We quantify these constraints by using scans of the 19-parameter space of the so-called phenomenological minimal supersymmetric Standard Model. The fraction of scan points that can be excluded by the Higgs measurements is studied for the coupling measurement accuracies obtained in LHC Run 2 and expected for the HL-LHC program and $e^+e^-$ colliders and contrasted with those derived from missing transverse energy searches at the LHC and from dark matter experiments., Comment: 27 pages, 14 figures

We analyse the new physics implications of theoretically clean $b \to s$ observables in a model-independent approach and compare their coherence with the implications of other rare $B$-decays. A statistical comparison is done between the New Physics explanation and hadronic contributions as the source of the anomalies in angular observables of the $B\to K^*\mu\mu$ decay. We make projections for future measurements that indicate that LHCb will be in the position to discover lepton non-universality via a single observable using the Run 3 data. The global fit of rare $B$-decays is given within a multidimensional fit involving all the 20 relevant Wilson coefficients., Comment: 6 pages, 1 figure. Based on talks given by S.N. at EPS-HEP2021 and by F.M. at Corfu2021 and SUSY2021

We present a first update on the constraints on general MSSM scenarios with non-minimal sources of flavour violation (NMFV). Using the public code SuperIso, we present an up-to-date computation of the relevant Wilson coefficients related to $b\to s ll$ transitions which manifest tensions with the SM predictions. We present benchmark scenarios compatible with the most recent fits to the Wilson coefficients. We finally discuss the possibility for such scenarios to completely explain the recent flavour anomalies., Comment: 6 pages, 4 figures, 1 table, contribution to the European Physical Society Conference on High Energy Physics (EPS-HEP2021)

We present a fully automated procedure providing an easy way to perform, systematically, phenomenological analyses in flavor physics for general BSM scenarios. This procedure relies on MARTY-1.4, is model independent and requires as input only the Lagrangian of the theory. Once the Lagrangian has been defined, tree-level and one-loop Wilson coefficients can be calculated symbolically by MARTY, from which flavor observables can be computed numerically by available software programs. We focus in particular on $b\to s\gamma$ and the recently updated $b\to s\ell^+\ell^-$ observables which are in tension with the SM, and present a general procedure to extract the relevant one-loop coefficients, such as $C_7$, $C_7^\prime$, $C_9$ and $C_{10}$., Comment: Contribution to The European Physical Society Conference on High Energy Physics (EPS-HEP2021), 4 pages

In Standard Model (SM) Higgs Boson pair production initiated by photons ($\gamma \gamma \to h h$) is loop-generated process and thereby very sensitive to any new couplings and particles that may come in loops. The Composite Higgs Models provide an alternate mechanism to address the hierarchy problem of SM where Higgs instead of being an elementary field could be a bound state of a strongly interacting sector. These set of models apart from modifying the SM Higgs couplings could also introduce new effective couplings that can have substantial impact on the loop processes. In this work we have studied the impact of such modifications by Composite Higgs models in $\gamma\gamma \to h h$ production process., Comment: 10 pages, 7 figures, minor updates, Talk presented at the International Workshop on Future Linear Colliders (LCWS2021), 15-18 March 2021. C21-03-15.1

We describe SuperIso v4.1, a public code for calculation of flavour observables, in the Standard Model and for New Physics scenarios in a model-independent way as well as for specific beyond the SM models such as two Higgs doublet models (2HDM), minimal supersymmetric Standard Model (MSSM) and next-to-minimal supersymmetric Standard Model (NMSSM)., Comment: 8 pages, 3 figures. Contribution to the proceedings of "Tools for High Energy Physics and Cosmology - TOOLS2020", Lyon, France

Dark matter represents currently an outstanding problem in both cosmology and particle physics. In this review we discuss the possible explanations for dark matter and the experimental observables which can eventually lead to the discovery of dark matter and its nature, and demonstrate the close interplay between the cosmological properties of the early Universe and the observables used to constrain dark matter models in the context of new physics beyond the Standard Model., Comment: 72 pages, 35 figures

Recently the LHCb collaboration has confirmed the evidence for lepton flavour nonuniversality at the $3.1\sigma$ level via an updated measurement of $R_K$. In this work we analyse this evidence within a model-independent approach. We make projections for future measurements which indicate that LHCb will be in the position to discover lepton nonuniversality with the Run 3 data in a single observable. We analyse other ratios based on our analysis of the present measurements of the ratios $R_{K^{(*)}}$ and analyse if they are able to differentiate between various new physics options within the effective field theory at present or in the near future. We also compare the present deviations in the ratios with NP indications in the angular observables of exclusive $b \to s \ell\ell$ transitions. Finally, we update our global analysis considering all $b \to s \ell\ell$ observables altogether, including a 20-parameter fit in connection of a Wilks' test., Comment: 16 pages, 12 tables, 5 figures. v2: comments on LEE and references added

MARTY is a C++ computer algebra system specialized for High Energy Physics that can calculate amplitudes, squared amplitudes and Wilson coefficients in a large variety of beyond the Standard Model scenarios up to the one-loop order. It is fully independent of any other framework and its main development guideline is generality, in order to be adapted easily to any type of model. The calculations are fully automated from the Lagrangian up to the generation of the C++ code evaluating the theoretical results (numerically, depending on the model parameters). Once a phenomenological tool chain has been set up - from a Lagrangian to observable analysis - it can be used in a model independent way leaving only model building, with MARTY, as the task to be performed by physicists. Here we present the main steps to build a general new physics model, namely gauge group, particle content, representations, replacements, rotations and symmetry breaking, using the example of a 2 Higgs Doublet Model. The sample codes that are shown for this example can be easily generalized to any Beyond the Standard Model scenario written with MARTY., Comment: Contribution to the proceedings of "Tools for High Energy Physics and Cosmology" - TOOLS2020, 14 pages, 2 figures

We analyse the results recently presented on the $B^{+} \to K^{*+} \mu^+ \mu^-$ angular observables by the LHCb Collaboration which show indications for New Physics beyond the Standard Model. Within a model-independent analysis, we compare the fit results with the corresponding results for the angular observables in $B^{0} \to K^{*0} \mu^+ \mu^-$., Comment: 3 pages, 5 tables, Addendum to arXiv:2006.04213. v2: LHCb reference added

The next generation electron-positron colliders are designed for precision studies of the Standard Model and its extensions, in particular in the Higgs sector. We consider the potential for discovery of composite Higgs models in Higgs pair production through photon collisions. This process is loop-generated, thus it provides access to all Higgs couplings and can show new physics effects in polarized and unpolarized cross-sections starting at relatively low collider energies. It is, therefore, relevant for all electron-positron colliders planned or in preparation. Sizeable deviations from the Standard Model predictions are present in a general class of composite Higgs models, as couplings of one or more Higgs bosons to fermions, or fermionic and scalar resonances, modify the destructive interference present in the Standard Model. In particular, large effects are due to the new quartic coupling of the Higgs to tops and to the presence of a light scalar resonance., Comment: v2: 31 pages, 17 figures, version accepted by JHEP. arXiv admin note: text overlap with arXiv:2105.11030

One of the main indications for New Physics in rare $B$-decays is deduced from the tension between experimental and Standard Model predictions of the angular analysis of the $B^0 \to K^{*0} \mu^+\mu^-$ decay. There are however possible non-local hadronic effects which in principle can also explain these tensions. In this work, we consider a statistical approach for differentiating the source of the tension in $B^0 \to K^{*0} \mu^+\mu^-$ observables and we also investigate the prospects of such a comparison with future data from the LHCb experiment., Comment: Based on talks given at FPCP2020 and ICHEP2020, 6 pages, 2 figures

Theoretical calculations Beyond the Standard Model (BSM) constitute a challenge for high energy physicists, but are necessary when searching for New Physics. The predictions of a BSM scenario need to be compared with experimental data and the Standard Model values in order to identify the model that fits better what we observe in particle colliders. BSM predictions require very involved and error prone calculations of amplitudes, cross-sections and Wilson coefficients. Calculations at the one-loop level are often necessary for these quantities since some phenomenologically important processes may not occur at tree-level, such as Flavor Changing Neutral Currents (FCNC) in flavor physics that vanish at the tree-level. One-loop calculations have to be done analytically which is very time consuming and in practice rarely done for general BSM models. Here we present MARTY, a public and open-source C++ code. MARTY is the very first independent program able to calculate automatically amplitudes, squared amplitudes and Wilson coefficients at the one-loop level for general BSM models. This type of calculations requires a computer algebra system and could only be done, up to now, using Mathematica, a commercial and closed software for symbolic manipulations. MARTY does not rely on Mathematica since it re-implements its own computer algebra system also in C++, called CSL. MARTY will considerably ease BSM studies as by automating the analytical calculations the main task of the user would be the model building part. Once interfaced with other phenomenological codes in particle physics, MARTY will be incredibly efficient to make detailed predictions for general BSM models automatically., Comment: Contribution to the 40th International Conference on High Energy physics - ICHEP2020, 6 pages, 4 figures

Studies Beyond the Standard Model (BSM) will become more and more important in the near future with a rapidly increasing amount of data from different experiments around the world. The full study of BSM models is in general an extremely time-consuming task involving long and difficult calculations. It is in practice not possible to do exhaustive predictions in these models by hand, in particular if one wants to perform a statistical comparison with data and the SM. Here we present MARTY (Modern ARtificial Theoretical phYsicist), a new C++ framework that fully automates calculations from the Lagrangian to physical quantities such as amplitudes or cross-sections. This framework can fully simplify, automatically and symbolically, physical quantities in a very large variety of models. MARTY can also compute Wilson coefficients in effective theories. This will considerably facilitate the study of BSM models in flavor physics. Contrary to the existing public codes in this field MARTY aims to give a unique, free, open-source, powerful and user-friendly tool for high-energy physicists studying predictive BSM models, in effective or full theories up to the 1-loop level, which does not rely on any external package. With a few lines of code one can gather final expressions that may be evaluated numerically for statistical analysis. Features like automatic generation and manual edition of Feynman diagrams, comprehensive manual and documentation, clear and easy to handle user interface are amongst notable features of MARTY., Comment: 23 pages, 7 figures

The new angular analysis of the decay $B \to K^* \ell^+ \ell^-$ recently presented by the LHCb Collaboration still indicates some tensions with the Standard Model predictions. There are several ongoing analyses to solve the problem of separating hadronic and New Physics effects in this decay, but the significance of the observed tensions in the angular observables in $B \to K^* \mu^+\mu^-$ is still dependent on a theory guesstimate of the hadronic contributions to these decays. Using the new data from LHCb we offer two tests which make a statistical comparison to determine whether the most favoured explanation of the anomalies is New Physics or underestimated hadronic effects. We then analyse the usefulness of these tests in two future scenarios. Finally, we update our global fits to all available $b \to s $ data and discuss the impact of the new LHCb measurements., Comment: 13 pages, 12 tables, 2 figures. v2: references added

The search for flavour-changing neutral current effects in $B$-meson decays is a powerful probe of physics beyond the Standard Model. Deviations from SM behaviour are often quantified by extracting the preferred values of the Wilson coefficients of an operator product expansion. We use the FlavBit module of the GAMBIT package to perform a simultaneous global fit of the Wilson coefficients $C_7$, $C_9$, and $C_{10}$ using a combination of all current data on $b \to s \mu^+ \mu^-$ transitions. We further extend previous analyses by accounting for the correlated theoretical uncertainties at each point in the Wilson coefficient parameter space, rather than deriving the uncertainties from a Standard Model calculation. We find that the best fit deviates from the SM value with a significance of 6.6$\sigma$. The largest deviation is associated with a vector coupling of muons to $b$ and $s$ quarks., Comment: 28 pages, 6 figures. v2: updated including recent experimental measurements (e.g. LHCb angular analysis of $B^+ \to K^{*+} \mu^+ \mu^-$ and LHCb and Belle angular analysis of $B \to K^* e^+ e^-$) in the fit

We consider the prospects for measuring distinctive signatures of the CP-violating phases in the minimal supersymmetric extension of the Standard Model (MSSM) in light of the limits on sparticle masses from searches at the LHC. We use the CPsuperH code to evaluate model predictions and scan the parameter space using a geometric approach that maximizes CP-violating observables subject to the current upper limits on electric dipole moments (EDMs). We focus on the possible CP-violating asymmetry $A_{\rm CP}$ in $b \to s \gamma$ decay and on a possible CP-violating contribution to the $B_s - \overline{B}_s$ mass difference $\Delta M^{NP}_{B_s}$, as well as future measurements of the EDMs of the proton, neutron and electron. We find that the current LHC and EDM limits are consistent with values of $A_{\rm CP}$, $\Delta M^{NP}_{B_s}$ and the proton EDM that are measurable with the Belle-II detector, LHCb and a proposed measurement of the proton EDM using a storage ring, respectively. Measurement of a non-zero proton EDM would constrain $A_{\rm CP}$ significantly, but it and a CP-violating contribution to $\Delta M^{NP}_{B_s}$ could still be measurable, along with neutron and electron EDMs. A more accurate measurement of $A_{\rm CP}$ with the current central value would favour stop and chargino masses within reach of future LHC runs as well as a potentially measurable value of $\Delta M^{NP}_{B_s}$., Comment: 20 pages, 12 figures. v2: references added, updated with the neutron EDM results by the nEDM collaboration

We present a brief update of our model-independent analyses of the b->s data presented in the articles published in Phys. Rev. D96 (2017) 095034 and Phys. Rev. D98 (2018) 095027 based on new data on R_K by LHCb, on R_{K^*} by Belle, and on B_{s,d}-> mu^+ mu^- by ATLAS., Comment: 7 pages, 3 figures, 3 tables. Addendum to Phys. Rev. D96 (2017) 095034 and Phys. Rev. D98 (2018) 095027

We present an overview of direct and indirect constraints in the MSSM, in CP-conserving and CP-violating MSSM scenarios, with some emphasis on the importance of combining the constraints from different sectors, namely SUSY and Higgs direct searches at the LHC, flavour physics, dark matter and electric dipole moments., Comment: 6 pages, 9 figures. Contribution to the proceedings of the Seventh Workshop on Theory, Phenomenology and Experiments in Flavour Physics, Capri, 8-10 June 2018

This is the third out of five chapters of the final report [1] of the Workshop on Physics at HL-LHC, and perspectives on HE-LHC [2]. It is devoted to the study of the potential, in the search for Beyond the Standard Model (BSM) physics, of the High Luminosity (HL) phase of the LHC, defined as $3~\mathrm{ab}^{-1}$ of data taken at a centre-of-mass energy of $14~\mathrm{TeV}$, and of a possible future upgrade, the High Energy (HE) LHC, defined as $15~\mathrm{ab}^{-1}$ of data at a centre-of-mass energy of $27~\mathrm{TeV}$. We consider a large variety of new physics models, both in a simplified model fashion and in a more model-dependent one. A long list of contributions from the theory and experimental (ATLAS, CMS, LHCb) communities have been collected and merged together to give a complete, wide, and consistent view of future prospects for BSM physics at the considered colliders. On top of the usual standard candles, such as supersymmetric simplified models and resonances, considered for the evaluation of future collider potentials, this report contains results on dark matter and dark sectors, long lived particles, leptoquarks, sterile neutrinos, axion-like particles, heavy scalars, vector-like quarks, and more. Particular attention is placed, especially in the study of the HL-LHC prospects, to the detector upgrades, the assessment of the future systematic uncertainties, and new experimental techniques. The general conclusion is that the HL-LHC, on top of allowing to extend the present LHC mass and coupling reach by $20-50\%$ on most new physics scenarios, will also be able to constrain, and potentially discover, new physics that is presently unconstrained. Moreover, compared to the HL-LHC, the reach in most observables will generally more than double at the HE-LHC, which may represent a good candidate future facility for a final test of TeV-scale new physics., Comment: Report from Working Group 3 on the Physics of the HL-LHC, and Perspectives at the HE-LHC; v2: final version updated with the latest contributions and summaries; 239 pages + refs; v3: typos and character misprint in Fig. 7.2 fixed; v4: added one missing author

Motivated by the success of the flavour physics programme carried out over the last decade at the Large Hadron Collider (LHC), we characterize in detail the physics potential of its High-Luminosity and High-Energy upgrades in this domain of physics. We document the extraordinary breadth of the HL/HE-LHC programme enabled by a putative Upgrade II of the dedicated flavour physics experiment LHCb and the evolution of the established flavour physics role of the ATLAS and CMS general purpose experiments. We connect the dedicated flavour physics programme to studies of the top quark, Higgs boson, and direct high-$p_T$ searches for new particles and force carriers. We discuss the complementarity of their discovery potential for physics beyond the Standard Model, affirming the necessity to fully exploit the LHC's flavour physics potential throughout its upgrade eras., Comment: Report from Working Group 4 on the Physics of the HL-LHC, and Perspectives at the HE-LHC, 292 pages

The LHCb experiment has made several measurements in $b \to s$ transitions which indicate tensions with the Standard Model predictions. Assuming the source of these tensions to be new physics, we present new global fits to all Wilson coefficients which can effectively receive beyond the Standard Model contributions. While the theoretically clean ratios $R_{K^{(*)}}$ which are sensitive to lepton flavour non-universality may unambiguously establish lepton non-universal new physics in the near future, most of the other tensions with the SM in the $b \to s$ data, in particular in the angular observables of the $B\to K^* \mu\mu$ decay and in the branching ratio of the $B_s \to \phi \mu\mu$ decay, depend on the estimates of non-factorisable power corrections. Therefore, we also analyse the dependence of the new global fit on these corrections., Comment: 6 pages, 2 figures. Based on a talk given at the Seventh Workshop on Theory, Phenomenology and Experiments in Flavour Physics, Capri, 8-10 June 2018, to appear in the Proceedings

We present some highlights on the complementaries of the Higgs and SUSY searches at the LHC, using the 8 and 13 TeV results. In particular, we discuss the constraints that can be obtained on the MSSM parameters by the determination of the Higgs boson mass and couplings. In addition, we investigate the interplay with heavy Higgs searches, and evaluate how higher LHC luminosities and a future linear collider can help probing the pMSSM Higgs sector and reconstructing the underlying parameters., Comment: 4 pages, 2 figures, contribution to the proceedings of the 39th International Conference on High Energy Physics (ICHEP2018), Seoul, 4-11 July 2018

Big-Bang nucleosynthesis (BBN) represents one of the earliest phenomena that can lead to observational constraints on the early Universe properties. It is well-known that many important mechanisms and phase transitions occurred before BBN. We discuss the possibility of gaining insight into the primordial Universe through studies of dark matter in cosmology, astroparticle physics and colliders. For this purpose, we assume that dark matter is a thermal relic, and show that combining collider searches with dark matter observables can lead to strong constraints on the period of freeze-out before BBN., Comment: 4 pages, 2 figures, contribution to the proceedings of the 39th International Conference on High Energy Physics (ICHEP2018), Seoul, 4-11 July 2018

SuperIso Relic is a public computing program for the calculation of flavour observables and relic density in supersymmetry (MSSM and NMSSM). We present new extensions of the code dedicated to the calculation of dark matter direct and indirect detection constraints from the latest experimental results. Contrary to most of the existing programs, this new version allows the user to consider straightforwardly the uncertainties related to nuclear form factors, dark matter density and velocity, as well as cosmic-ray propagation through the galactic medium. The user thus finds a direct way to calculate "conservative", "standard" or "stringent" constraints according to the chosen set of uncertainties. Some examplified results showing the impact of such uncertainties are also presented., Comment: 4 pages, 2 figures, contribution to the proceedings of the 39th International Conference on High Energy Physics (ICHEP2018), Seoul, 4-11 July 2018

We present the physics program of the Belle II experiment, located on the intensity frontier SuperKEKB $e^+e^-$ collider. Belle II collected its first collisions in 2018, and is expected to operate for the next decade. It is anticipated to collect 50/ab of collision data over its lifetime. This book is the outcome of a joint effort of Belle II collaborators and theorists through the Belle II theory interface platform (B2TiP), an effort that commenced in 2014. The aim of B2TiP was to elucidate the potential impacts of the Belle II program, which includes a wide scope of physics topics: B physics, charm, tau, quarkonium, electroweak precision measurements and dark sector searches. It is composed of nine working groups (WGs), which are coordinated by teams of theorist and experimentalists conveners: Semileptonic and leptonic B decays, Radiative and Electroweak penguins, phi_1 and phi_2 (time-dependent CP violation) measurements, phi_3 measurements, Charmless hadronic B decay, Charm, Quarkonium(like), tau and low-multiplicity processes, new physics and global fit analyses. This book highlights "golden- and silver-channels", i.e. those that would have the highest potential impact in the field. Theorists scrutinised the role of those measurements and estimated the respective theoretical uncertainties, achievable now as well as prospects for the future. Experimentalists investigated the expected improvements with the large dataset expected from Belle II, taking into account improved performance from the upgraded detector., Comment: 689 pages

We show how knowledge of the cold dark matter (CDM) density can be used, in conjunction with measurements of the parameters of a scenario for beyond the Standard Model (BSM) physics, to provide information about the evolution of the Universe before Big Bang Nucleosynthesis (BBN). As examples of non-standard evolution, we consider models with a scalar field that may decay into BSM particles, and quintessence models. We illustrate our calculations using various supersymmetric models as representatives of classes of BSM scenarios in which the CDM density is either larger or smaller than the observed density when the early Universe is assumed to be radiation-dominated. In the case of a decaying scalar field, we show how the CDM density can constrain the initial scalar density and the reheating temperature after it decays in BSM scenarios that would yield overdense dark matter in standard radiation-dominated cosmology, and how the decays of the scalar field into BSM particles can be constrained in scenarios that would otherwise yield underdense CDM. We also show how the early evolution of the quintessence field can be constrained in BSM scenarios., Comment: 25 pages, 11 figures

We describe SuperIso Relic, a public program for the calculation of dark matter relic density and direct and indirect detection rates, which includes in addition the SuperIso routines for the calculation of flavour physics observables. SuperIso Relic v4 incorporates many new features, namely the possibility of multiprocessor calculation of the relic density, new cosmological models, and the implementations of the calculation of the observables related to direct and indirect detection experiments. Furthermore, the new version includes an implementation of the nuclear and astrophysical uncertainties, from namely nuclear form factors, dark matter density and velocity, as well as cosmic ray propagation through the galactic medium., Comment: 50 pages, 5 figures, 2 tables. SuperIso Relic can be obtained from http://superiso.in2p3.fr/relic/

Assuming the source of the anomalies observed recently in $b \to s$ data to be new physics, there is a priori no reason to believe that - in the effective field theory language - only one type of operator is responsible for the tensions. We thus perform for the first time a global fit where all the Wilson coefficients which can effectively receive new physics contributions are considered, allowing for lepton flavour universality breaking effects as well as contributions from chirality flipped and scalar and pseudoscalar operators, and find the SM pull taking into account all effective parameters. As a result of the full fit to all available $b \to s$ data including all relevant Wilson coefficients, we obtain a total pull of 4.1$\sigma$ with the SM hypothesis assuming 10% error for the power corrections. Moreover, we make a statistical comparison to find whether the most favoured explanation of the anomalies is new physics or underestimated hadronic effects using the most general parameterisation which is fully consistent with the analyticity structure of the amplitudes. This Wilks' test will be a very useful tool to analyse the forthcoming $B\to K^* \mu^+ \mu^-$ data. Because the significance of the observed tensions in the angular observables in $B \to K^* \mu^+\mu^-$ is presently dependent on the theory estimation of the hadronic contributions to these decays, we briefly discuss the various available approaches for taking into account the long-distance hadronic effects and examine how the different estimations of these contributions result in distinct significance of the new physics interpretation of the observed anomalies., Comment: 20 pages, 7 figures. v2: $F_H(B^+ \to K^+ \mu^+ \mu^-)$ added to the global fit (with no significant change in the results), references added. v3: typos corrected

The Randall-Sundrum model with a deformed metric can generate light Kaluza-Klein (KK) Higgs modes consistent with the electroweak precision analysis for a certain range of parameters. The first KK mode of the Higgs ($h_{1}$) in such a model could lie in the mass range varying from 800 GeV to 1.3 TeV. We find that the $h_{1}$ is gaugephobic and decays dominantly into a $t\bar{t}$ pair. The search strategy for $h_{1}$ decaying to $t\bar{t}$ at the Large Hadron Collider (LHC) in this low mass range has been studies. We have used substructure tools to suppress the large QCD background associated with this channel. We find that $h_{1}$ can be probed at the LHC., Comment: 11 pages