There are strong similarities between charge-parity (CP) violating observables in hadronic $B$ decays (in particular $ΔA^-_{\rm CP}$ in $B\to Kπ$) and direct CP violation in Kaon decays ($ε^\prime$): All these observables are very sensitive to new physics (NP) which is at the same time CP and isospin violating (i.e. NP with complex couplings which are different for up quarks and down quarks). Intriguingly, both the measurements of $ε^\prime$ and $ΔA^-_{\rm CP}$ show deviations from their Standard Model predictions, calling for a common explanation (the latter is known as the $B\to Kπ$ puzzle). For addressing this point, we parametrize NP using a gauge invariant effective field theory approach combined with a global $U(2)^3$ flavor symmetry in the quark sector (also known as less-minimal flavour violation). We first determine the operators which can provide a common explanation of $ε^\prime$ and $ΔA^-_{\rm CP}$ and then perform a global fit of their Wilson coefficients to the data from hadronic $B$ decays. Here we also include e.g. the recently measured CP asymmetry in $B_s\to KK$ as well as the purely isospin violating decay $B_s\toϕρ^0$, finding a consistent NP pattern providing a very good fit to data. Furthermore, we can at the same time explain $ε^\prime/ε$ for natural values of the free parameters within our $U(2)^3$ flavour approach, and this symmetry gives interesting predictions for hadronic decays involving $b\to d$ transitions.
Motivated by the measurements of $b\to s\ell^+\ell^-$ transitions, including $R(K)$ and $R(K^*)$, we examine lepton flavour (universality) violation in $B$ decays and its connections to $μ\to eγ$ in generic leptoquark models. Considering all 10 representations of scalar and vector leptoquarks under the Standard Model gauge group we compute the tree-level matching for semileptonic $b$-quark operators as well as their loop effects in $\ell\to\ell^\primeγ$. In our phenomenological analysis we correlate $R(K)$, $R(K^*)$ and the other $b\to sμ^+μ^-$ data to $μ\to eγ$ and $b\to sμe$ transitions for …
We show that the factorization assumption in colour-suppressed $B$ meson decays is not ruled out by experimental data on $B \ra K(K^*) + J/Ψ(Ψ^{'})$. The problem previously pointed out might be due to an inadequate choice of hadronic form factors. Within the Isgur-Wise SU(2) heavy flavour symmetry framework, we search for possible $q^2$-dependences of form factors that satisfy both the large longitudinal polarization $ρ_L$ observed in $B \ra K^* + J/Ψ$ and the relatively small ratio of rates $R_{J/Ψ} = Γ(B \ra K^* + J/Ψ)/Γ(B \ra K + J/Ψ)$. We find out that the puzzle could be essentially under…
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 $\approx3\,σ$ 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}_1γ^μσ^I\ell_1)(\bar{q}_1γ_μσ^Iq_1…
The antenna subtraction formalism allows to calculate QCD corrections to jet observables. Within this formalism, the subtraction terms are constructed using antenna functions describing all unresolved radiation between a pair of hard radiatior partons. In this paper, we focus on the subtraction terms for double real radiation contributions to jet observables in hadron-hadron collisions evaluated at NNLO. An essential ingredient to these subtraction terms are the four-parton antenna functions with both radiators in the initial state. We outline the construction of the double real subtraction te…
We describe the phenomenology of the flavour changing neutral current sector of a supersymmetric model, invariant under the T' discrete flavour group. This model has been proposed in Ref.[1] and describes realistic leptonic and hadronic masses and mixings and predicts the amount of flavour changing in terms of the small flavour breaking parameter u in [0.007, 0.05]. For small values of u, the model almost reduces to the MSUGRA framework, while sizable deviations from MSUGRA can be, instead, observed when larger values of u and tan(beta) are considered. We analyse in detail the T' BR(mu --> e g…
Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and $\ell$--$τ$ conversion in nuclei, with $\ell = e,μ$. Based on available experimental limits, we establish constraints on the Wilson coefficients of the operators contributing to these processes. Our work paves the way to extract the related information from Belle II and foreseen future experiments.
Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and $\ell$-$τ$ conversion in nuclei ($\ell=e,μ$). Based on available experimental limits, we establish constraints on the Wilson coefficients of the operators contributing to these processes. The related information from Belle II and foreseen future experiments can be easily incorporated into the resulting framework.
A new phenomenological approach is suggested to determine the strangeness contents of light-flavour isoscalars. This approach is based on phenomenological laws of hadron production related to the spin, isospin, strangeness content and mass of the particles. The ``effective'' numbers of s and \bar{s} quarks in the isoscalar partners i_1 and i_2 are given by the nonstrange-strange mixing angle ϕ: k(i_1)=2\sin^2ϕand k(i_2)=2\cos^2ϕ. From the total production rates per hadronic Z decay of all light-flavour hadrons measured so far at LEP the values for k are found to be: k(η) \equiv 2-k(η^{\prime})…
The possibility for a common effective field theory for hadronic molecules with different heavy-quark flavours is examined critically. It is argued that such a theory does not allow one to draw definite conclusions for doubly heavy molecules. In particular, it does not allow one to relate binding energies for the molecules in the c-quark and b-quark sectors with controlled uncertainties. Therefore, while this kind of reasoning does not preclude from employing heavy-quark spin symmetry for charmonium- and bottomonium-like states separately within a well established effective field theory framew…
We report on the creation of a database for quarkonium and open heavy-flavour production in hadronic collisions. This database, made as a collaboration between HepData and the ReteQuarkonii network of the integrating activity I3HP2 of the 7th Framework Programme, provides an up-to-date review on quarkonia and open heavy-flavour existing data. We first present the physics motivation for this project, which is connected to the aim of the ReteQuarkonii network, studies of open heavy-flavour hadrons and quarkonia in nucleus-nucleus collisions. Then we give a general overview of the database and de…
A serious computational problem in the evaluation of hadronic collision processes is connected with the large number of partonic subprocesses included in the calculation. These are from the quark and gluon content of the initial hadrons, and from CKM quark mixing. For example, there are 180 subprocesses which contribute to the $W$+2jets process, and 292 subprocesses in $W$+3jets production at the LHC, even when quarks from only the first two generations are taken into account. We propose a simple modification of the rules for evaluation of cross sections and distributions, which avoids multipl…
We propose measurements of weighted differences of the angular observables in the rare decays $B \to K^*\ell^+\ell^-$. The proposed observables are very sensitive to the difference between the Wilson coefficients $\mathcal{C}_9^{(e)}$ and $\mathcal{C}_9^{(μ)}$ for decays into electrons and muons, respectively. At the same time, the charm-induced hadronic contributions are kinematically suppressed to $\lesssim 7\% (4\%)$ in the region $1\,$GeV$^2 \leq q^2 \leq 6\,$GeV$^2$, as long as LFU breaking occurs only in $\mathcal{C}^{(\ell)}_{9}$. This suppression becomes stronger for the region of low …
We present a four-flavour lattice calculation of the leading-order hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon, $a_\mathrmμ^{\rm hvp}$, arising from quark-connected Feynman graphs. It is based on ensembles featuring $N_f=2+1+1$ dynamical twisted mass fermions generated by the European Twisted Mass Collaboration (ETMC). Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass. We employ three lattice spacings to examine lattice artefacts and several different volumes to check for finite-size effects. In…
Supersymmetric (SUSY) Grand Unified theories (GUTs) generally predict FCNC and CP violating processes to occur both in the leptonic and hadronic sectors. Assuming an underlying SU(5) group plus right-handed neutrinos (RN), we perform an extensive study of FCNC and CP violation, analyzing the correlations between leptonic and hadronic processes like mu-> e gamma and K-Kbar mixing, tau->mu gamma and b -> s transitions such as B_d -> phi K_s and Bs-Bsbar mixing. Moreover, we examine the impact of the considered scenario on the UT analyses, monitoring the low energy consequences implied by possibl…
We review theoretical approaches to form factors that arise in heavy-meson decays and are hadronic expressions of non-perturbative QCD. After motivating their origin in QCD factorisation, we retrace their evolution from quark-model calculations to non-perturbative QCD techniques with an emphasis on formulations of truncated heavy-light amplitudes based upon Dyson-Schwinger equations. We compare model predictions exemplarily for the B\toπtransition form factor and discuss new results for the g_{D*Dπ} coupling in the hadronic D* decay.
We present a determination of the QCD coupling constant, $α_s$, obtained by fitting lattice results for the flavour $ud$ hadronic vacuum polarisation function to continuum perturbation theory. We use $n_f=2+1$ flavours of Domain Wall fermions generated by the RBC/UKQCD collaboration and three lattice spacings $a^{-1}=1.79,\, 2.38$ and $3.15\ \text{GeV}$. Several sources of potential systematic error are identified and dealt with. After fitting and removing expected leading cut-off effects, we find for the five-flavour $\overline{\text{MS}}$ coupling the value $α_s(M_Z)=0.1181(27)^{+8}_{-22}$, …
I estimate the SU(3) flavour symmetry breaking in the ratio of penguin-to-tree ratios of the decays B_s\to K^+ K^- and B_d\toπ^+π^-, given an assumption on the flavour symmetry breaking of the hadronic input parameters. The decay amplitudes are calculated in QCD factorization. Implications for the determination of gamma are discussed.
Summmary talk at the Workshop on Sin and Flavour in Hadronic and Electromagnetic Interactions, Turin (Italy), september 1992, to appear in the Proceedings,
We consider the transverse-momentum distribution of heavy flavours in hadronic collisions. We present a formalism in which large transverse-momentum logarithms are resummed at the next-to-leading level, and mass effects are included exactly up to order α_strong^3, so as to retain predictivity at both small and large transverse momenta. As an example, we apply our formalism to b production at the Tevatron.
We consider the flavour-changing operators associated with the strong axial and trace anomalies. Their short-distance generation through penguin-like diagrams is obtained within the QCD external field formalism. Standard-model operator evolution exhibits a suppression of anomalous effects in K and B hadronic weak decays. A genuine set of dimension-eight Delta S = 1 operators is also displayed.
In this article, we have considered an extension of the inert Higgs doublet model with $SU(2)_L$ singlet vector like fermions. Our model is capable of addressing some interesting anomalous results in $b\to s\ell^+\ell^-$ decays (like $R(K^{(*)})$) and in muon $(g-2)$. Apart from explaining these anomalies, and being consistent with other flavour data, the model satisfies relevant constraints in the dark matter sector, while remaining within the reach of ongoing direct detection experiments. The model also produces signatures at the large hadron collider (LHC) with final states comprised of dil…
I discuss three B physics results with potential for exhibiting new flavour-changing interactions: (1) the time-dependent CP asymmetry in B\to J/ψK_S decay; (2) branching fractions and CP asymmetries in B\to ππ, πK decays; (3) inclusive and exclusive semi-hadronic b\to s transitions.
We review recent results of Lattice QCD calculations relevant for flavour physics. We discuss in particular the hadronic parameters entering the amplitudes of K0-K0bar, D0-D0bar and B0-B0bar mixing, the B- and D-meson decay constants and the form factors controlling B-meson semileptonic decays. On the basis of these lattice results, which are extensively collected in the paper, we also derive our averages of the relevant hadronic parameters.
Hadronic spectroscopy can be introduced to students and developed rather far without requiring SU(N) flavour symmetry. In such a "minimalist" presentation, we are naturally led to comment and clarify the concept of the "generalized" Pauli principle.
We report on our ongoing project to determine the leading-order hadronic vacuum polarisation contribution to the muon $g-2$, using ensembles with $N_f=2+1$ flavours of O($a$) improved Wilson quarks generated by the CLS effort, with pion masses down to the physical value. We employ O($a$) improved versions of the local and conserved vector currents to compute the contributions of the light, strange and charm quarks to $(g-2)_μ$, using the time-momentum representation. We perform a detailed investigation of the systematic effects arising from constraining the long-distance regime of the vector c…
We derive a strong bound on the chromo-electric dipole moment of the charm quark, and we quantify its impact on models that allow for a sizeable flavour violation in the up quark sector. In particular we show how the constraints coming from the charm and up CEDMs limit the size of new physics contributions to direct flavour violation in D meson decays. We also specialize our analysis to the cases of split-families Supersymmetry and composite Higgs models. The results we expose motivate an increase in experimental sensitivity to fundamental hadronic dipoles, and a further exploration of the SM …
Until now the focus within the direct search for supersymmetry has mainly been on flavour diagonal observables. Recently lepton flavour violating signals at future electron positron colliders have been studied. There is now an opportunity to analyse the relations between collider observables and low-energy observables in the hadronic sector. In a first work in this direction, we study flavour violation in the squark decays of the second and third generations taking into account results from B physics, in particular from the rare decay b ->s gamma. Correlations between various squark decay mode…
We present a study of the Higgs boson decay branching ratios to $b\bar{b}$, $c\bar{c}$ and gluons, one of the cornerstones of the physics program at the International Linear Collider (ILC). A standard model Higgs boson of 120\,GeV mass, produced in the Higgs-strahlung process at $\sqrt{s} = 250$\,GeV was investigated using the full detector simulation and reconstruction procedures. The analysis was performed in the framework of the Silicon Detector (SiD) concept with full account of inclusive standard model backgrounds. The selected decay modes contained two heavy flavour jets in the final sta…
We analyze fluctuations of quark number and electric charge, in 2-flavour QCD at finite temperature and vanishing net baryon number density. In the hadronic phase we find that an enhancement of charge fluctuations arises from contributions of doubly charged hadrons to the thermodynamics. The rapid suppression of fluctuations seen in the high temperature phase suggests that in the QGP quark number and electric charge are predominantly carried by quasi-particles with the quantum numbers of quarks.
Leptophobic Z' gauge bosons can appear in models with an E_6 gauge symmetry. We show that flavour-changing neutral currents can be generated in some of these models due to the mixing of the ordinary d_R, s_R and b_R quark fields with the exotic h_R. Because the Z' does not couple to charged leptons, the constraints on the flavour-changing couplings U^{Z'}_{db} and U^{Z'}_{sb} are relatively weak. Indeed, B_q--Bbar_q mixing (q=d,s) can be dominated by Z' exchange, which will affect CP-violating rate asymmetries in B decays. Rare hadronic B decays can also be affected, while decays involving cha…
We study the impact of the inverse seesaw mechanism on several leptonic and hadronic low-energy flavour-violating observables in the context of the Minimal Supersymmetric Standard Model. Indeed, the contributions of the light right-handed sneutrinos from the inverse seesaw significantly enhance the Higgs-mediated penguin diagrams. We find that this can increase the different branching ratios by as much as two orders of magnitude.
We have studied neutrinoless double beta decay and charged lepton flavour violation in broken $μ-τ$ symmetric neutrino masses in a generic left-right symmetric model (LRSM). The leading order $μ-τ$ symmetric mass matrix originates from the type I (II) seesaw mechanism, whereas the perturbations to $μ-τ$ symmetry in order for generation of non-zero reactor mixing angle $θ_{13}$, as required by latest neutrino oscillation data, originates from the type II (I) seesaw mechanism. In our work, we considered four different realizations of $μ-τ$ symmetry, viz. Tribimaximal Mixing (TBM), Bimaximal Mixi…
Within the standard approach of effective field theory of weak interactions for $ΔB = 1$ transitions, we look for possibly unexpected subtle New Physics effects, here dubbed "flavourful Easter eggs". We perform a Bayesian global fit using the publicly available HEPfit package, taking into account state-of-the-art experimental information concerning these processes, including the suggestive measurements from LHCb of $R_{K}$ and $R_{K^{*}}$, the latter available only very recently. We parametrize New Physics contributions to $b \to s$ transitions in terms of shifts of Wilson coefficients of the …
We first study the hadronic lepton flavor violating tau decays within the littlest Higgs model with T-parity (including one or two pseudoscalars, or a vector resonance). We consider the case where only T-odd particles and partner fermions contribute, and also its extension including Majorana neutrinos coming from an inverse seesaw. In both cases our mean values lie only one order of magnitude below current upper limits, strengthening the case of searching for these decays in the quest for new physics.
We investigate the constraints on the flavour violating parameters from the decay B --> X_s gamma, taking into account the interplay of the various sources of flavour violation in the unconstrained MSSM. We present a systematic leading logarithmic QCD analysis of these model-independent constraints, including contributions from gluinos, neutralinos, charginos, charged Higgs bosons and interferences between them. We show that two simple combinations of elements of the down squark mass matrix are stringently bounded over large parts of the parameter space where only weak assumptions on the hiera…
We present an analysis of non-leptonic B decays in the minimally flavour-violating MSSM with large tan(beta). We relate the Wilson coefficients of the relevant hadronic scalar operators to leptonic observables, showing that the present limits on the Bs->mu+ mu- and B+->tau nu_tau branching fractions exclude any visible effect in hadronic decays. We study the transverse helicity amplitudes of B->VV decays, which exhibit an enhanced sensitivity to the scalar operators, showing that even though an order one modification relative to the SM is not excluded in some of these amplitudes, they are too …
We analyse the process Z-zero to M1 M2, where M1 and M2 are pseudoscalar mesons with quark contents of q1 q-bar and q-bar q2 respectively. At the quark level, the process-zero to q1 q2-bar, where q1 and q2 are quarks of different flavours, receives contribution only from the Z-penguin. In order to fold the quark-level process to the hadronic process, we make the fundamental assumption that the vertex of type M q q-bar can be approximated by an effective constant gamma 5 coupling. With this assumption, estimates are obtained for the cross-sections for the following processes: Z-zero to K-minus …
I review recent results and prospects for improvement in calculations of hadronic matrix elements relevant to quark flavour phenomenology. I will focus on key quantities for CKM unitarity triangle analyses and for the study of discrepancies between experiment and SM predictions for some flavour observables.
We consider the decay of a heavy flavour into an inclusive hadronic state X of invariant mass m_X small with respect to its energy E_X, m_X << E_X. The electron spectrum and the hadronic mass distribution in semileptonic b -> u decays, or the photon spectrum in b -> s gamma decays, all require, close to their endpoints, a control over this region. This region is affected both by non-perturbative phenomena related to the Fermi motion of the heavy quark and by perturbative soft gluon radiation in the final state (Sudakov form factor).Fermi motion can be described by the shape function f (m*), wh…
The comparison of the theoretical and experimental determinations of the anomalous magnetic moment of the muon $(g-2)_μ$ constitutes one of the strongest tests of the Standard Model at low energies. In this article, we compute the leading hadronic contribution to $(g-2)_μ$ using lattice QCD simulations employing Wilson quarks. Gauge field ensembles at four different lattice spacings and several values of the pion mass down to its physical value are used. We apply the O($a$) improvement programme with two discretizations of the vector current to better constrain the approach to the continuum li…
We report on a high-precision calculation of the Bhabha process in Quantum Electrodynamics, of interest for precise luminosity determination of electron-positron colliders involved in R measurements in the region of hadronic resonances. The calculation is based on the matching of exact next-to-leading order corrections with a Parton Shower algorithm. The accuracy of the approach is demonstrated in comparison with existing independent calculations and through a detailed analysis of the main components of theoretical uncertainty, including two-loop corrections, hadronic vacuum polarization and l…
We study the bounds on minimal lepton flavour violation in the context of Type-III see-saw imposed by LHC Run I search for events which contain two charged leptons (either electron or muons of equal or opposite sign), two jets from a hadronically decaying $W$ boson and large missing transverse momentum. In this scenario the flavour structure of the couplings of the triplet fermions to the Standard Model leptons can be reconstructed from the neutrino mass matrix and lepton number violation is very suppressed. We find that using the information on charge and flavour of the leptons in the above f…
In this talk, multiquarks are studied microscopically in a standard quark model. In pure ground-state pentaquarks the short-range interaction is computed and it is shown to be repulsive, a narrow pentaquark cannot be in the groundstate. As a possible excitation, an additional quark-antiquark pair is then considered, and this is suggested to produce linear molecular system, with a narrow decay width. This excitation may be energetically favourable to the p-wave excitation suggested by the other pentaquark models. Here, the quarks assemble in three hadronic clusters, and the central hadron provi…
The recent results by the Fermilab Lattice and MILC collaborations on the hadronic matrix elements entering $B_{d,s}-\bar B_{d,s}$ mixing show a significant tension of the measured values of the mass differences $ΔM_{d,s}$ with their SM predictions. We review the implications of these results in the context of Constrained Minimal Flavour Violation models. In these models, the CKM elements $γ$ and $|V_{ub}|/|V_{cb}|$ can be determined from $B_{d,s}-\bar B_{d,s}$ mixing observables, yielding a prediction for $γ$ below its tree-level value. Determining subsequently $|V_{cb}|$ from the measured va…
In these lectures, I present several important applications of QCD sum rules to the decay processes involving heavy-flavour hadrons. The first lecture is introductory. As a study case, the sum rules for decay constants of the heavy-light mesons are considered. They are relevant for the leptonic decays of $B$-mesons. In the second lecture I describe the method of QCD light-cone sum rules used to calculate the heavy-to-light form factors at large hadronic recoil, such as the $B\to π\ell ν_\ell$ form factors. In the third lecture, the nonlocal hadronic amplitudes in the flavour-changing neutral c…
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 $B\to K^*μμ$ 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 mult…
These lectures present a pedagogical introduction to the physics of heavy-flavour production in hadronic collisions. The first lecture gives the theoretical background, with a discussion of leading-order calculations and of the effects of next-to-leading-order corrections. The origin and implications of the large logarithmic corrections appearing at this order are presented in an elementary way. The second lecture provides a survey of current experimental data on charm and bottom production, and describes their comparison with theoretical predictions. We emphasize the role played by some non-p…
Motivated by recent indications that the rates of colour-allowed non-leptonic channels are not in agreement with their Standard Model expectations based on QCD factorisation, we investigate the potential to study CP asymmetries with these decays. In the Standard Model, these flavour-specific decays are sensitive to CP violation in $B^0_{(s)}$--$\bar{B}^0_{(s)}$ mixing, which is predicted with low uncertainties and can be measured precisely with semileptonic decays. If there are beyond Standard Model contributions to the non-leptonic decay amplitudes, there could be significant enhancements to …
We present results of calculations of the hadronic vacuum polarisation contribution to the muon anomalous magnetic moment. Specifically, we focus on controlling the infrared regime of the vacuum polarisation function. Our results are corrected for finite-size effects by combining the Gounaris-Sakurai parameterisation of the timelike pion form factor with the Lüscher formalism. The impact of quark-disconnected diagrams and the precision of the scale determination is discussed and included in our final result in two-flavour QCD, which carries an overall uncertainty of 6%. We present preliminary …
Some important aspects of hadronic tau decays are reviewed: the determination of alpha_s from the inclusive tau hadronic width, the measurement of |V_{us}| through the Cabibbo-suppressed decays of the tau, and the theoretical description of the tau -> nu_tau K pi spectrum. The present status of other relevant electroweak topics, such as charged-current universality tests or bounds on lepton-flavour violation, has been already summarized in a previous review.
The possibility to discriminate between different operators contributing to lepton flavour violating tau decays is discussed within an effective field theory framework. Correlations among decay rates in different channels as well as differential distributions in many-body decays are considered. Recent developments in the determination of the hadronic form factors for $τ\rightarrow \ell ππ$ ($\ell = e, μ$) decays are incorporated in the analysis. The above issues are exemplified by considering a Higgs-like boson with lepton flavour violating couplings. Implications of the search for lepton flav…
We derive bounds on the electric and chromo-electric dipole moments of the charm quark. The second one turns out to be particularly strong, and we quantify its impact on models that allow for a sizeable flavour violation in the up quark sector, like flavour alignment and Generic U(2)^3. In particular we show how the bounds coming from the charm and up CEDMs constrain the size of new physics contributions to direct flavour violation in D decays. We also specialize our analysis to the cases of Supersymmetry with split families and composite Higgs models. The results exposed in this paper motivat…
The predictions for the B_{s,d}-\bar B_{s,d} mixing mass differences ΔM_{s,d} and Br(B_{s,d}\toμ\barμ) within the Standard Model (SM) and its extensions suffer from considerable hadronic uncertainties present in the B_{s,d}-meson decay constants F_{B_{s,d}} that enter these quantities quadratically. We point out that in the restricted class of models with minimal flavour violation (MFV) in which only the SM low energy operators are relevant, the ratios Br(B_{q}\toμ\barμ)/ΔM_q (q=s,d) do not depend on F_{B_{q}} and the CKM matrix elements. They involve in addition to the short distance function…