The most general basis of operators parametrizing a low-scale departure from the SM particle content is constructed. The SM gauge invariance is enforced, and operators of lowest dimensions are retained separately for a new light neutral particle of spin 0, 1/2, 1, and 3/2. The basis is further decomposed into couplings to the SM Higgs/gauge fields, to pairs of quark/lepton fields, and to baryon/lepton number violating combinations of fermion fields. This basis is then used to systematically investigate the discovery potential of the rare FCNC decays of the K and B mesons with missing energy in the final state. The most sensitive decay modes in the s to d, b to d, and b to s sectors are identified and compared for each type of couplings to the new invisible state.
We study the effects of a vector-like SU(2) quark doublet as a fourth generation. In this model we examine the chiral structure and the FCNC in the quark sector by using radiative B meson decays in the allowed region for parameters from $R_b = {Γ_{qq}}/{Γ_{had.}}$. We compute the ratio $R = {Br (b \to d γ)}/{Br (b \to s γ)}$ in the model which realizes a different chiral structure as well as FCNC. The constraints has been extracted from the experimental results of B meson decays, the $T_{new}$ parameter of oblique corrections and $R_b$. Under the natural assumption that the violation of the $V…
In this work we analyse a non-minimal Lorentz-violating extension of the electroweak theory in the fermionic sector. Firstly we analyse the relation between the CKM rotation in the quark sector and possible contributions of this new coupling to flavour changing neutral currents (FCNC) processes. In sequel we look for non-diagonal terms through possible leptonic flavour violation (LFV) decays. Strong bounds are presented to the Lorentz violating parameters of both the quark and the leptonic sectors.
We show that in the model of hidden sector of the Universe, interacting with the Standard-Model sector through the photonic portal, the Standard-Model Coulomb potential gets a tiny hidden-sector additive correction that might turn out to be either exciting or fatal for the verification of this model.
A new weak-isospin triplet of scalar bosons is introduced to the Standard Model in order to ensure the electroweak symmetry for a conjectured new weak coupling between a hidden sector of the Universe, responsible for cold dark matter, and the Standard-Model sector (involving now the new triplet). The considered coupling may be called "electroweak portal" to the structure of hidden sector. After spontaneously breaking the electroweak symmetry by the Standard-Model Higgs mechanism, it includes the so called "photonic portal" introduced by us previously.
A weak photon interaction with the hidden sector of the Universe, introduced recently to realize a "photonic portal", (to such a hypothetic sector responsible for cold dark matter), is conjectured to be embedded in a more extended weak interaction displaying electroweak symmetry spontaneously broken by the Standard-Model Higgs mechanism. This is a hypothetic new weak interaction between hidden and Standard-Model sectors of the Universe, appearing in our model in addition to the conventional electroweak interaction acting in the Standard-Model sector.
We present a SUSY model with four Higgs doublets of the ``private type", where each fermion type (up, down, and charged leptons) obtain their masses from a different Higgs doublet H_f ( f = u_1, d, e). The conditions for anomaly cancellation, imply that the remaining Higgs doublet of the model (H_{u_2}), must have the same hypercharge as H_{u_1}, and thus can only couple to up-type quarks, which opens the possibility to have FCNC's only in this sector. We study the Lagrangian of the model, and in particular the Higgs potential, in order to identify the Higgs mass-eigenstates and their interact…
We introduce a new class of renormalisable models, consisting of a dark $SU(2)_D$ gauge sector connected to the Standard Model (SM) through a Vector-Like (VL) fermion mediator, not requiring a Higgs portal, in which a massive vector boson is the Dark Matter (DM) candidate. These models are labelled Fermion Portal Vector Dark Matter (FPVDM). Multiple realisations are possible, depending on the properties of the VL partner and of the scalar potential. One example is discussed in detail. FPVDM models have a large number of applications in collider and non-collider experiments, depending on the me…
The mirror twin Higgs framework allows for a natural Higgs mass while being consistent with collider bounds on colored symmetry partners to standard model quarks. This mechanism relies crucially on a discrete symmetry which relates each standard model field to a mirror partner. These partners are charged under gauge groups identical to, but distinct from, those in the standard model. The minimal twin Higgs scenario provides only one low-energy connection between the visible and twin sectors, the light Higgs boson. We present a new class of portals connecting the two sectors, using fields that …
Flavour-Changing-Neutral-Currents (FCNC) play an important r\^ ole in testing the Standard Model (SM) while probing the possibility of having New Physics beyond the SM. In the SM, FCNC are forbidden at three level, but arise through calculable one-loop contributions. We review some of the features of FCNC in two examples of minimal extensions of the SM. In the first example, we consider an extension of the SM consisting of the addition of one vector-like quark either of the up-type ($Q=2/3$) or the down type ($Q=- 1/3$). In this extension there are non-vanishing but naturally suppressed Z-medi…
Constructing $SU(N)$ strongly coupled dark sectors by extending the Standard Model: mixed representations, flavor structure, global symmetries and various portals
Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS)（宇宙理论物理中心，基础科学研究院）
We propose an alternative method of constructing two Higgs-doublet models free from scalar mediated FCNC couplings at the tree-level. In a toy scenario, we have presented semi realistic textures for the Yukawa matrices, which can reproduce the approximate flavor structure in the quark sector. Presence of flavor diagonal but nonuniversal Yukawa couplings emerges as a distinguishing feature of such models.
"Portal" models that connect the Standard Model to a Dark Sector allow for a wide variety of scenarios beyond the simplest WIMP models. Kinetic mixing of gauge fields in particular has allowed a broad range of new ideas. However, the models that evade CMB constraints are often non-generic, with new mass scales and operators to split states and suppress indirect detection signals. Models with a "portalino", a neutral fermion that marries a linear combination of a standard model neutrino and dark sector fermion and carries a conserved quantum number, can be simpler. This is especially interestin…
We conduct a general discussion of supersymmetric models with three families in the Higgs sector. We analyse the scalar potential, and investigate the minima conditions, deriving the mass matrices for the scalar, pseudoscalar and charged states. Depending on the Yukawa couplings and the Higgs spectrum, the model might allow the occurrence of potentially dangerous flavour changing neutral currents at the tree-level. We compute model-independent contributions for several observables, and as an example we apply this general analysis to a specific model of quark-Higgs interactions, discussing how …
We describe more precisely the mechanism of spontaneous mass generation in the previously proposed model of hidden sector of the Universe. The hidden sector is conjectured to consist of sterile spin-1/2 fermions (sterinos) whose mass is spontaneously generated by sterile scalar bosons (sterons), while their interactions are mediated by sterile antisymmetric-tensor bosons (A bosons). Such a sector communicates with the familiar Standard Model sector through a photonic portal acting weakly between both sectors (but stronger than the universal gravity). This is due to photons which, beside sterin…
We propose an extension of the Standard Model (SM) with a $U_{A'}(1)$ gauge invariant dark dector connected to the SM via a new portal -- the Stueckelberg portal, arising in the framework of dark photon $A'$ mass generation via Stueckelberg mechanism. This portal opens through the effective dim=5 operators constructed from the covariant term of the auxiliary Stueckelberg scalar field $σ$ providing flavor non-diagonal renormalizable couplings of both $σ$ and $A'$ to the SM fermions $ψ$. The Stueckelberg scalar plays a role of Goldstone boson in the generation of mass of the Dark Photon. Contrar…
The flavor changing neutral current (FCNC) transitions t --> q'H and t --> q'V_i (V_i=γ, g, Z) are studied in the context of the effective Lagrangian approach. We focus on the scenario in which these decays are predominantly induced by new physics effects arising from the Yukawa sector extended with dimension-six SU_L(2) X U_Y(1)-invariant operators, which generate the most general CP-even and CP-odd tq'H vertex at the tree level. For the unknown coefficients, we assume a slightly modified version of the Cheng-Sher ansatz. We found that the branching ratio for the Higgs-mediated FCNC t--> q'V_…
The timeon model recently proposed by Friedberg and Lee has a potential problem of flavor changing neutral currents (FCNCs) if the mass of the timeon is small. In order to avoid, we introduce a small dimensionless parameter to suppress FCNCs. Even in this case, we find that the timeon mass must be larger than 151 GeV to satisfy all the constraints from processes involving FCNCs in the quark sectors. We also extend the timeon model to the lepton sector and examine the leptonic processes.
In the supersymmetric models with nontrivial flavour structure in the soft-breaking sector the exchange of neutral Higgses mediates $ΔF=2$ transitions. This mechanism is studied for $ΔS, ΔB=2$ processes and for a generic form of the soft-breaking terms. We find that Higgs-mediated FCNC amplitudes increase very rapidly with $\tanβ$ and can exceed $SUSY$ box contribution by up to two orders of magnitude when $\tanβ\sim m_t/m_b$.
We study baryogenesis via a gaugino portal, the supersymmetric counterpart to the widely studied kinetic mixing portal, to a hidden sector. CP and baryon number violating decays of a hidden sector gaugino into the visible sector can produce the observed baryon asymmetry of the Universe. The tiny portal coupling is crucial in producing late out-of-equilibrium decays, after washout processes that can erase the asymmetry have gone out of equilibrium. We study this mechanism within various scenarios, including freeze-in or freeze-out of the hidden gaugino, as well as extended frameworks where the …
If the hidden sector contains more than one U(1) groups, additional dim-4 couplings (beyond the kinetic mixing) between the massive U(1) fields and the hypercharge generally appear. These are of the form similar to the Chern-Simons interactions. We study the phenomenology of such couplings including constraints from laboratory experiments and implications for dark matter. The hidden vector fields can play the role of dark matter whose characteristic signature would be monochromatic gamma ray emission from the galactic center. We show that this possibility is consistent with the LHC and other l…
According to the Standard Model (SM), we expect to find a proton for each decaying neutron. However, the experiments counting the number of decayed neutrons and produced protons have a disagreement. This discrepancy suggests that neutrons might have an exotic decay to a Dark Sector (DS). In this paper, we explore a scenario where neutrons decay to a dark Dirac fermion $χ$ and a non-abelian dark gauge boson $W'$. We discuss the cosmological implications of this scenario assuming DS particles are produced via freeze-in. In our proposed scenario, DS has three portals with the SM sector: (1) the f…
We explore the use of the Inverse Amplitude Method for unitarization of scattering amplitudes to derive the existence and properties of possible new heavy states associated with perturbative extensions of the electroweak breaking sector of the Standard Model starting from the low energy effective theory. We use a toy effective theory generated by integrating out a heavy singlet scalar and compare the pole mass and width of the unitarized amplitudes with those of the original model. Our results show that the Inverse Amplitude Method reproduces correctly the singlet mass up to factors of O(1-3),…
We analyse the constraints and some of the phenomenological implications of a class of two Higgs doublet models where there are flavour-changing neutral currents (FCNC) at tree level but the potentially dangerous FCNC couplings are suppressed by small entries of the CKM matrix $V$. This class of models have the remarkable feature that, as a result of a discrete symmetry of the Lagrangian, the FCNC couplings are entirely fixed in the quark sector by $V$ and the ratio $v_2 /v_1$ of the vevs of the neutral Higgs. The discrete symmetry is extended to the leptonic sector, so that there are FCNC in …
If dark matter (DM) interacts with the Standard Model (SM) via the kinetic mixing (KM) portal, it necessitates the existence of massive, likely $\gsim 1$ TeV, enabler portal matter (PM) particles that carry both dark and SM quantum numbers which will appear in vacuum polarization-like loop graphs. Such heavy states are only directly accessible at high energy colliders and apparently lie at mass scales beyond the direct kinematic reach of the ILC, CEPC and FCC-ee. A likely possibility is that these new particles are part of the 'next step' toward a UV-complete scenario describing both the SM an…
We examine current constraints on and the future sensitivity to the strength of couplings between quarks and neutrinos in the presence of a form factor generated from loop effects of hidden sector particles that interact with quarks via new interactions. We consider models associated with either vector or scalar interactions of quarks and leptons generated by hidden sector dynamics. We study constraints on these models using data from coherent elastic neutrino-nucleus scattering and solar neutrino experiments and demonstrate how these new interactions may be discovered by utilizing the recoil …
Relation between the lepton and quark mixings: $U_{PMNS} \approx V_{CKM}^{\dagger} U_X$, where $U_X$ is the BM or TBM mixing matrices, implies the quark-lepton (Grand) unification and existence of hidden sector with certain flavor symmetries. The latter couples to the visible sector via the neutrino portal and is responsible for $U_X$, as well as for smallness of neutrino mass. GUT ensures appearance of $\sim V_{CKM}$ in the lepton mixing. General features of this scenario (inverse or double seesaw, screening of the Dirac structures, basis fixing symmetry) are described and two realizations ar…
We study the quark sector of the universal seesaw model with SU(2)$_L$ $\times$ SU(2)$_R$ $\times$ $U(1)$.The model incorporates the seesaw mechanism with the vector-like quarks (VLQs). The purpose of this work is to study the model with the effective theory. After integrating the heavy five VLQs, we derive the effective theory with four up-type quark and three down type quark. In this work, the FCNC of Z boson for top quark and top$^\prime$ quark is derived.
We analyze the neutrino phenomenology in an $SU(5)$ F-theory model with both a visible sector and a twin hidden sector. At low energies, the strong and weak scales of the two sectors may differ but the spectrum of states is described by the MSSM (MSSM$^\prime$) in the visible (twin) sectors. What is special about the model is that there are right-handed neutrinos which couple to both sectors via Yukawa couplings. As a result, assuming 3 right-handed neutrinos with a large mass much greater than the weak scale, at tree-level the seesaw mechanism results in 3 massive Majorana neutrinos and 3 mas…
In the context of Supersymmetric Grand Unified theories with soft breaking terms arising at the Planck scale, it is generally possible to link flavor changing neutral current and CP violating processes occurring in the leptonic and hadronic sectors. We study the correlation between flavor changing squark and slepton mass insertions in models à la SU(5). We show that the constraints coming from lepton flavor violation exhibit a strong impact on CP-violating B decays.
High-energy $γγ$ colliders constitute a potential running mode of future $e^+ e^-$ colliders such as the ILC and CLIC. We study the sensitivity of a high-energy $γγ$ collider to the Higgs portal scenario to a hidden sector above the invisible Higgs decay threshold. We show that such $γγ$ collisions could allow to probe the existence of dark sectors through the Higgs portal comparatively more precisely than any other planned collider facility, from the unique combination of sizable cross-section with clean final state and collider environment. In addition, this search could cover the singlet Hi…
We examine the sensitivity of electric dipole moments (EDMs) to new $CP$-violating physics in a hidden (or dark) sector, neutral under the Standard Model (SM) gauge groups, and coupled via renormalizable portals. In the absence of weak sector interactions, we show that the electron EDM can be induced purely through the gauge kinetic mixing portal, but requires five loops, and four powers of the kinetic mixing parameter $ε$. Allowing weak interactions, and incorporating the Higgs and neutrino portals, we show that the leading contributions to $d_e$ arise at two-loop order, with the main source …
Millennium Institute for Subatomic Physics at the High-Energy Frontier (SAPHIR) of ANID（智利国家研究与创新署高能前沿亚原子物理千年研究所）；Center for Theoretical and Experimental Particle Physics, Facultad de Ciencias Exactas, Universidad Andres Bello（安第斯贝尔纳多·奥伊金斯大学精确科学学院理论与实验粒子物理中心）；Institut für Theoretische Physik, Universität Tübingen, Kepler Center for Astro and Particle Physics（蒂宾根大学理论物理系开普勒天体与粒子物理中心）；Bogoliubov Laboratory of Theoretical Physics, JINR（杜布纳联合核子研究所鲍戈留博夫理论物理实验室）；Matrosov Institute for System Dynamics and Control Theory SB RAS（俄罗斯科学院西伯利亚分院马特罗索夫系统动力学与控制理论研究所）
The Higgs sector of the Standard Model offers a unique opportunity to probe the hidden sector. The Higgs squared operator is the only dimension two operator which is Lorentz and gauge invariant. It can therefore couple both to scalar curvature and the hidden sector at the dim--4 level. We consider the possibility that a combination of the Higgs and a singlet from the hidden sector plays the role of inflaton, due to their large couplings to gravity. This implies that the quartic couplings satisfy certain constraints which leads to distinct low energy phenomenology, including Higgs signals at th…
We consider models with fermionic dark matter that transforms under a non-Abelian dark gauge group. Exotic, vector-like leptons that also transform under the dark gauge group can mix with standard model leptons after spontaneous symmetry breaking and serve as a portal between the dark and visible sectors. We show in an explicit, renormalizable model based on a dark SU(2) gauge group how this can lead to adequate dark matter annihilation to a standard model lepton flavor so that the correct relic density is obtained. We identify a discrete symmetry that allows mass mixing between the vector-lik…
The large number of top quarks produced at the LHC and possible future hadron colliders allows to study rare decays of this particle. In many well motivated models of new physics, for example in non-minimal composite-Higgs models, the existence of scalar singlets can induce new flavor-violating top decays surpassing the Higgs contribution by orders of magnitude. We study the discovery prospects of rare top decays within such models and develop new search strategies to test these interactions in top pair-produced events at the LHC. We demonstrate that scales as large as $10$--$50$ TeV can be pr…
We investigate several phenomena related to FCNCs in the $\text{3-3-1-1}$ model. The sources of FCNCs at the tree-level from both the gauge and Higgs sectors are clarified. Experiments on the oscillation of mesons most stringently constrain the tree-level FCNCs. The lower bound on the new physics scale is imposed more tightly than in the previous, $\text{M}_{\text{new}}>12 $ \text{TeV}. Under this bound, the tree-level FCNCs make a negligible contribution to the $\text{Br}(B_s \rightarrow μ^+ μ^-)$, $\text{Br}(B \rightarrow K^{*} μ^+ μ^-)$ and $\text{Br}(B^{+}\rightarrow K^{+}μ^{+}μ^{-})$. The…
We present an extensive analysis of a model in which the (Majorana) Dark Matter candidate is a mixture between a SU(2) singlet and two SU(2) doublets. This kind of setup takes the name of singlet-doublet model. We will investigate in detail an extension of this model in which the Dark Matter sector interactions with a 2-doublet Higgs sector enforcing the complementarity between Dark Matter phenomenology and searches of extra Higgs bosons.
The observations in the $B_{s}$ sector suggest the existence of some new physics contribution to the $B_S-\bar{B}_s$ mixing. We study the implications of a hypothesis that this contribution is generated by the Higgs induced flavour changing neutral currents. We concentrate on the specific $b\to s$ transition which is described by two complex FCNC parameters $F_{23}$ and $F_{32}$ and parameters in the Higgs sector. Model independent constraints on these parameters are derived from the $B_S-\bar{B}_s$ mixing and are used to predict the branching ratios for $\bar{B}_s\to μ^+μ^-$ and $\bar{B}_d\to…
A broad program of searches at high intensity experiments during the coming decade and beyond will sensitively probe new light mediator particles interacting through the minimal renormalizable vector, Higgs, and neutrino portals as well as higher-dimension axion-like particle portals. These portals may link the visible and dark sectors and play a critical role in many proposed solutions to some of the big open questions in particle physics and cosmology. In this whitepaper, we survey the theoretical and experimental progress, status, and prospects in the study of minimal dark sector portals.
Asymmetric dark matter (ADM) is an attractive framework relating the observed baryon asymmetry of the Universe to the dark matter density. A composite particle in a new strong dynamics is a promising candidate for ADM as the strong dynamics naturally explains the ADM mass in the GeV range. Its large annihilation cross section due to the strong dynamics leaves the asymmetric component to be dominant over the symmetric component. In such composite ADM scenarios, the dark sector has a relatively large entropy density in the early Universe. The large dark sector entropy results in the overclosure …
The Cabibbo-Kobayashi-Maskawa (CKM) mixing matrix and flavor-changing neutral currents (FCNC's) in the quark sector are examined in the GUT inspired $SO(5) \times U(1) \times SU(3)$ gauge-Higgs unification in which the 4D Higgs boson is identified with the Aharonov-Bohm phase in the fifth dimension. Gauge invariant brane interactions play an important role for the flavor mixing in the charged-current weak interactions. The CKM matrix is reproduced except that the up quark mass needs to be larger than the observed one. FCNC's are naturally suppressed as a consequence of the gauge invariance, wi…
In this work we calculate the effects of the electroweak flavour changing neutral currents dimension six effective operators on single top production at the LHC. These results are then combined with previous ones we have obtained for the strong sector. This allow us, for the first time, to perform a combined analysis of flavour changing neutral currents in top production with all contributing dimension six operators. Finally, we study the feasibility of their observation and characterization both at the Tevatron and at the LHC.
Recent experimental results on exclusive semi-tauonic B meson decays show sizable deviations from the standard model prediction, while the recent result on pure-tauonic decay reduces the deviation from the prediction. These results suggest an indirect evidence of new physics in which the structure of the relevant weak charged interaction may differ from that of the standard model. We study these tauonic B decays in the context of extensions of the Higgs sector. As a result, we find that two Higgs doublet models without tree-level FCNC are unlikely to explain the present experimental data while…
Pairs of Standard Model fermions form dimension-3 singlet operators that can couple to new dark sector states. This "fermion portal" is to be contrasted with the lower-dimensional Higgs, vector and neutrino singlet portals. We characterise its distinct phenomenology and place effective field theory bounds on this framework, focusing on the case of fermion portals to a pair of light dark sector fermions. We obtain current and projected limits on the dimension-6 effective operator scale from a variety of meson decay experiments, missing energy and long-lived particle searches at colliders, as we…
The Higgs sector of the Standard Model offers a unique probe of the hidden sector. In this work, we explore the possibility of renormalizable Higgs couplings to the hidden sector vector fields which can constitute dark matter (DM). Abelian gauge sectors with minimal field content, necessary to render the gauge fields massive, have a natural Z_2 parity. This symmetry ensures stability of the vector fields making them viable dark matter candidates, while evading the usual electroweak constraints. We illustrate this idea with the Stueckelberg and Higgs mechanisms. Vector DM is consistent with the…
We present a version of the Type II Seesaw mechanism for parametrically small Dirac neutrino masses. Our model starts from an $\text{SU}(2)_\text{L} \otimes \text{SU}(2)'\otimes \text{U}(1)_\text{X}$ gauge extension of the Standard Model involving a sector of mirror fermions. A bidoublet scalar with a very small vacuum expectation value connects the SM leptons with their mirror counterparts and we can identify the mirror neutrino with the right-handed neutrino. Similar to the conventional Type II Seesaw, our particle spectrum features singly- and doubly-charged scalars. The strong CP problem i…
The Higgs field mass term, being superrenomalizable, has a unique status within the standard model. Through the opening it affords, $SU(3) \times SU(2) \times U(1)$ singlet fields can have renormalizable couplings to standard model fields. We present examples that are neither grotesque nor unnatural. A possible consequence is to spread the Higgs particle resonance into several weaker ones, or to afford it additional, effectively invisible decay channels.
We discuss the sensitivity of neutrino experiments at the luminosity frontier to generic hidden sectors containing new (sub)-GeV neutral states. The weak interaction of these states with the Standard Model can be efficiently probed through all of the allowed renormalizable `portals' (in the Higgs, vector, and neutrino sectors) at fixed target proton beam facilities, with complementary sensitivity to colliders. We concentrate on the kinetic-mixing vector portal, and show that certain regions of the parameter space for a new secluded U(1) gauge sector with long-lived sub-GeV mass states decaying…
As a minimal theory of fermion masses we extend the SM by heavy vectorlike fermions, with flavor-anarchical Yukawa couplings, that mix with chiral fermions such that small SM Yukawa couplings arise from small mixing angles. This model can be regarded as an effective description of the fermionic sector of a large class of existing flavor models and thus might serve as a useful reference frame for a further understanding of flavor hierarchies in the SM. Already such a minimal framework gives rise to FCNC effects through exchange of massive SM bosons whose couplings to the light fermions get modi…
Many models of Higgs portal Dark Matter (DM) find themselves under pressure from increasingly tight direct detection constraints. In the framework of gauge field DM, we study how such bounds can be relaxed while retaining the thermal WIMP paradigm. When the hidden sector gauge symmetry is broken via the Higgs mechanism, the hidden sector generally contains unstable states which are lighter than dark matter. These states provide DM with an efficient annihilation channel. As a result, the DM relic abundance and the direct detection limits are controlled by different parameters, and the two can e…
We introduce a dark neutrino sector which respects a hidden $U(1)^\prime$ gauge symmetry, subsequently broken by the vacuum expectation value of a dark scalar. The model is a self-consistent realisation of an extended hidden sector that communicates with the SM only via the three renormalizable portals, namely neutrino, vector and scalar mixing. The interplay between portal couplings leads to several novel signatures in heavy neutrino, dark photon, and dark scalar searches, typically characterised by multi-leptons plus missing energy and displaced vertices. A striking signature arises in kaon …
Many extensions of the Standard Model(SM) generate contributions to Flavor Changing Neutral Current(FCNC) processes that must have sufficient flavor suppression to be consistent with experiments, if the new physics (NP) is associated with a scale of a TeV. Here we present a mechanism for suppressing the NP effects to FCNC processes. We consider the possibility that the source of NP contributions to FCNC processes share the same flavor symmetry underlying the SM source of FCNC processes which are the quark and lepton mass matrices. We call this the principle of shared flavor symmetry. In the fl…
