We study the Higgs sector of supersymmetric models containing two Higgs doublets with a light MSSM-like CP odd Higgs, $m_A \lesssim 10$ GeV, and $\tan β\lesssim 2.5$. In this scenario all of the Higgses resulting from two Higgs doublets: light and heavy CP even Higgses, $h$ and $H$, the CP odd Higgs, $A$, and the charged Higgs, $H^\pm$, could have been produced at LEP or the Tevatron, but would have escaped detection because they decay in modes that have not been searched for or the experiments are not sensitive to. Especially $H \to ZA$ and $H^\pm \to W^{\pm \star} A$ with $A \to c \bar c, τ^+ τ^-$ present an opportunity to discover some of the Higgses at LEP, the Tevatron and also at B factories. Typical $τ$- and $c$-rich decay products of all Higgses require modified strategies for their discovery at the LHC.
We analyse the mass spectrum of the Constrained Minimal Supersymmetric Standard Model at the low tan beta fixed point. We find that the model only satisfies experimental and dark matter bounds in regions where the vacuum is meta-stable -- ie where it violates `unbounded from below' (UFB) bounds. Adding a small amount of R-parity violation solves these problems but the absolute upper bound on the lowest higgs mass m_{h^0}<97 GeV remains. We present the predicted sparticle mass spectrum as a function of the gluino mass m_g.
We demonstrate, through the study of the one-loop effective potential in the MSSM, the existence of fully model-independent lower and upper theoretical bounds on $\tan β$. We give their general analytic form and illustrate some of their implications.
Talk given at PASCOS 2012, Merida, Mexico describing work in progress in collaboration with Archana Anandakrishnan, Christopher Plumberg and Akin Wingerter.
The Bs-Bsbar mixing parameter Delta Ms is studied in the MSSM with large tan beta. The recent Tevatron measurement of Delta Ms is used to constrain the MSSM parameter space. From this analysis the often neglected contribution to Delta Ms from the operator Q^SLL is found to be significant.
Following previous works regarding electroweak precision tests in supersymmetry, we continue to explore their implications to the MSSM and NMSSM both of which are tightly constrained by the Higgs mass and its decay experiments at the LHC. We adopt universal squark, slepton mass of three generations, and A-term of all SM fermions. We determine the flows of both MSSM and NMSSM in the $S$-$T$ plane with increasing $\tanβ$ and/or $γγ$ rate. Either increasing the value of $R_γ$ or $\tanβ$, we find that the benchmark points tend to be pushed outside the contour at 99% CL in the MSSM, however, conver…
One of the main implications of the LHC discovery of a Higgs boson with a mass $M_h \approx 126$ GeV is that the scale of supersymmetry-breaking in the Minimal Supersymmetric Standard Model (MSSM) might be rather high, $M_S \gg M_Z$. In this paper, we consider the high $M_S$ regime and study the spectrum of the extended Higgs sector of the MSSM, including the LHC constraints on the mass and the rates of the observed light $h$ state. In particular, we show that in a simplified model that approximates the important radiative corrections, the unknown scale $M_S$ (and some other leading SUSY param…
We consider tan(beta)-enhanced quantum effects in the minimal supersymmetric standard model (MSSM) including those from the Higgs sector. To this end, we match the MSSM to an effective two-Higgs doublet model (2HDM), assuming that all SUSY particles are heavy, and calculate the coefficients of the operators that vanish or are suppressed in the MSSM at tree-level. Our result clarifies the dependence of the large-tan(beta) resummation on the renormalization convention for tan(beta), and provides analytic expressions for the Yukawa and trilinear Higgs interactions. The numerical effect is analyze…
We discuss corrections to $ΔM_{B_d}$, $ΔM_{B_s}$ and to the CP violation parameter $ε$ in two examples of (generalized) minimal flavour violation models: 2HDM and MSSM in the large $\tanβ$ limit. We show that for $H^+$ not too heavy, $ΔM_{B_s}$ in the MSSM with heavy sparticles can be substantially smaller than in the SM due the charged Higgs box contributions and in particular due to the growing like $\tan^4β$ contribution of the double penguin diagrams involving neutral Higgs boson exchanges.
A systematic analysis of Higgs-mediated contributions to the Bd and Bs mass differences is presented in the MSSM with large values of tan(beta). In particular, supersymmetric corrections to Higgs self-interactions are seen to modify the correlation between Delta Mq and BR(Bq --> mu+ mu-) for light Higgses. The present experimental upper bound on BR(Bs --> mu+ mu-) is nevertheless still sufficient to exclude noticeable Higgs-mediated effects on the mass differences in most of the parameter space.
In the context of the Minimal Supersymmetric extension of the Standard Model (MSSM), we reanalyze the search for the heavier CP-even $H$ and CP-odd $A$ neutral Higgs bosons at the LHC in their production in the gluon-fusion mechanism and their decays into gauge and lighter $h$ bosons and into top quark pairs. We show that only when considering these processes, that one can fully cover the entire parameter space of the Higgs sector of the model. Indeed, they are sensitive to the low $\tanβ$ and high Higgs mass ranges, complementing the traditional searches for high mass resonances decaying into…
We analyze the impact of Higgs-mediated amplitudes on the rare decays KL -> pi0 nu nu-bar and K+ -> pi+ nu nu-bar in the MSSM with large tan(beta) and general flavour mixing. We point out that, going beyond the minimal flavour violation hypothesis, Z-penguin amplitudes generated by charged-Higgs exchange can induce sizable modifications of K -> pi nu nu-bar rates. Interestingly, these effects scale as tan^4(beta) at the amplitude level. For large values of tan(beta), this mechanism allows deviations from the SM expectations even for tiny (CKM-type) off-diagonal mixing terms in the right-handed…
Study of the MSSM in large tan$β$ regime has to include correlations between the constraints presented by the low energy values of the b quark mass and $BR(b\to sγ)$. Both quantities receive SUSY contributions enhanced by tan$β$ and have a major impact on the MSSM analysis. Here we summarize the results of such a study constrained by minimal SO(10) unification. We show the best fits, in the $(m_0,M_{1/2})$ plane, obtained in the global analysis spanned over the gauge, Yukawa and SUSY parameter space at the unification scale. Two distinct fits describe the available low-energy data very well. T…
In the MSSM, the CP parities of the neutral Higgs bosons may be mixed by radiative effects induced by explicit CP violation in the third generation of squarks. To allow for this possibility, we argue that the charged Higgs-boson mass and tan(beta) should be used to parametrize the MSSM Higgs sector. We introduce a new benchmark scenario of maximal CP violation appropriate for direct searches of CP-violating MSSM Higgs bosons. We show that the bounds established by LEP 2 on the MSSM Higgs sector may be substantially relaxed at low and intermediate values of tan(beta) in the presence of CP viola…
For large values of tan(beta) interesting effects arise in the MSSM due to the enhancement of down-quark self-energies. These effects are well-studied within the decoupling limit, i.e. in the limit of supersymmetric masses far above the electroweak scale. In this article I discuss those issues which emerge from a treatment of these effects that goes beyond the decoupling limit.
Well-known and newly developed renormalization schemes for $\tanβ$ are analyzed in view of three desirable properties: gauge independence, process independence, and numerical stability in perturbation theory. Arguments are provided that no scheme can meet all three requirements, and as an illustration, a ``No-Go-Theorem'' for the renormalization of $\tanβ$ is established. Nevertheless, two particularly attractive schemes emerge. A discussion about which scheme might be the best compromise in practice is given.
We investigate two-loop gluino corrections to the effective Lagrangian for $b\to s+γ(g)$ in the minimal supersymmetric extension of the standard model (MSSM) at large $\tanβ$, including the contributions in which quark flavor change is mediated by charginos. Using the translation invariant of loop momenta and the Ward-Takahashi identities (WTIs) that are required by the $SU(3)_c\times U(1)_{_{em}}$ gauge invariance, we simplify our expressions to concise forms. As an example, we discuss two-loop gluino corrections to the CP asymmetry of inclusive $B\to X_{_s}γ$ decay in CP violating MSSM.
Minimal supersymmetric standard model with R-parity violation (RPVMSSM) contributes to the P-, CP-odd four-quark interaction. The P-, CP-odd four-quark interaction is constrained by the new 199Hg EDM experimental data. It is then possible to constrain R-parity violating (RPV) couplings from the 199Hg EDM data. In this talk, we analyze the RPV contribution to the P-, CP-odd four- quark interaction at the one-loop level to give constraints on RPV parameters.
We construct a supersymmetric model based on the semi-simple gauge group $SU(3)_c \times SU(3)_L \times SU(3)_R$ with the relation $tanβ\simeq m_t/m_b$ automatically arising from its structure. The model below a scale $\sim 10^{16}$ GeV gives naturally rise just to the minimal supersymmetric standard model and therefore to the presently favored values for $sin^2 θ_w$ and $α_s$ without fields in representations higher than the fundamental.
We study the predictions for M_top, tan(beta) and V_cb in a popular texture ansatze for the fermion mass matrices. We do this both for the Minimal Supersymmetric Standard Model (MSSM) and for the simplest model (MSSM-BRpV) where a bilinear R-Parity violating term is added to the superpotential. We find that taking the experimental values for M_top and V_cb at 99 % C.L. and the GUT relations h_b=h_tau and (V_cb)^2=h_c/h_t within 5 %, the large tan(beta) solution, characteristic in the MSSM with bottom--tau unification, becomes disallowed. In contrast the corresponding allowed region for the MSS…
We present results of our study of tan(beta)-enhanced loop corrections in the Minimal Supersymmetric Standard Model (MSSM) with Minimal Flavour Violation (MFV). We demonstrate that these corrections induce flavour changing neutral current (FCNC) gluino couplings which have a large impact on the Wilson coefficient C_8 of the chromomagnetic operator. To illustrate the phenomenological consequences of this gluino-squark contribution to C_8, we briefly discuss its effect on the mixing-induced CP asymmetry in the decay B_d -> phi K_S.
We investigate the MSSM with very large tan(beta) > 50, where the fermion masses are strongly affected by loop-induced couplings to the "wrong" Higgs, imposing perturbative Yukawa couplings and constraints from flavour physics. Performing a low-energy scan of the MSSM with flavour-blind soft terms, we find that the branching ratio of B->tau nu and the anomalous magnetic moment of the muon are the strongest constraints at very large tan(beta) and identify the viable regions in parameter space. Furthermore we determine the scale at which the perturbativity of the Yukawa sector breaks down, depen…
The possibility of identification of an observable CMS $μ^+ μ^-$ excess at 28 GeV in the channel $pp\to μ^+ μ^- b \bar b$ at $\sqrt{s}$=8 TeV and 13 TeV as a manifestation of one of the minimal supersymmetric standard model (MSSM) Higgs bosons is investigated. The MSSM parametric scenarios in the regime of large threshold corrections involving low-mass CP-odd scalar, a 125 GeV CP-even scalar and other Higgs bosons with suitable masses are found, where the alignment limit conditions for the Higgs couplings are respected. Perturbative unitarity bounds and constraints on the electroweak vacuum st…
We investigate the constraints to the light neutralino dark matter scenario in the minimal supersymmetric standard model from available experimental observations such as decays of B and K meson, relic dark matter abundance, and the search for neutralino and Higgs production at colliders. We find that two regions of the MSSM parameter space fulfill all the constraints: a fine-tuned strip with large tan beta where the lightest neutralino can be as light as 8 GeV, and a low tan beta region providing a neutralino mass larger than 16 GeV. The large tan beta strip, which can be compatible with recen…
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 …
In the NonHolomorphic Supersymmetric Standard Model (NHSSM), the Yukawa couplings of the bottom quark ($y_b$) and the tau lepton ($y_τ$) might receive substantial supersymmetric (SUSY) radiative corrections which have prominent dependencies on the NHSSM-specific trilinear soft parameters, $A_b^\prime$ and $A_τ^\prime$, respectively, in addition to their well-known dependence on $\tanβ$ as is already present in the Minimal SUSY Standard Model (MSSM). We study to what extent these could affect the production cross sections of the heavy Higgs bosons ($H$ and $A$) in association with a pair of $b$…
We investigate the possibilities for constraining tan beta within the MSSM by combining the theoretical result for the upper bound on the lightest Higgs-boson mass as a function of tan beta with the informations from the direct experimental search for this particle. We discuss the commonly used ``benchmark'' scenario, in which the parameter values m_top = 175 GeV and M_susy = 1 TeV are chosen, and analyze in detail the effects of varying the other SUSY parameters. We furthermore study the impact of the new diagrammatic two-loop result for mh, which leads to an increase of the upper bound on mh…
Current Higgs data at the Large Hadron Collider is compatible with a SM signal at the 2$σ$ level, but the central value of the signal strength in the diphoton channel is enhanced with respect to the SM expectation. If the enhancement resides in the diphoton partial decay width, the data could be accommodated in the Minimally Supersymmetric Standard Model (MSSM) with highly mixed light staus. We revisit the issue of vacuum instability induced by large mixing in the stau sector, including effects of a radiatively-corrected tau Yukawa coupling. Further, we emphasize the importance of taking into …
The muon anomalous magnetic moment $a_μ$ is studied in the infinite $\tanβ$ limit of the MSSM. Since the muon mass arises completely from loop effects, large corrections to $a_μ$ are expected in comparison to the usual case with moderately high $\tanβ$. Due to the qualitatively different parameter dependence, the gap between the experimental value and the Standard Model prediction can be filled only in parameter volumes in which a mass hierarchy suppresses the chargino loop in favour of the neutralino contribution. Two such possibilities are found to have either large Higgsino mass or large mu…
We consider a two-loop contribution of Higgs-mediated penguin diagram to $B(B_s \to μ^+μ^-)$ at large $\tanβ$ in the MSSM, motivated by a recently proposed two-loop magnetic penguin diagrams by Chen and Geng [1]. Typically the two-loop diagram is a $α_s$ correction to the one-loop contributions. However the new contribution can dominate one-loop contributions in a region of parameter space where $μ$, $A_t$ and $A_b$ are very large and scalar top, scalar bottom and charged Higgs are light. Both constructive and destructive interferences are possible. The total branching ratio can be drastically…
We discuss various improvements of the prediction for the light MSSM Higgs boson mass in the hybrid framework of the public code FeynHiggs, which combines fixed-order and effective field theory results. First, we discuss the resummation of logarithmic contributions proportional to the bottom-Yukawa coupling including two-loop $Δ_b$ resummation. For large $\tanβ$, these improvements can lead to large upward shifts of the Higgs mass compared to the existing fixed-order calculations. Second, we improve the implemented EFT calculation by fully taking into account the effect of $\mathcal{CP}$-viola…
A complete experiment on decay $K_L \to l^+ l^-$ will not only consist of measurement of the decay rates but also lepton polarization etc. These additional observations will yield tests of CP invariance in these decays. In $K_L$ and $K_S$ decays, the e mode is slower than the $μ$ mode by roughly $(m_e/m_μ)^2$ \cite{sehgal1}. As well discussed in literature \cite{herczeg} the Standard Model contribution to the lepton polarization is of order $2 \times \sim 10^{-3}$. We show that in MSSM with large \tanbeta and light higgs masses ($\sim 2 M_W$), the longitudinal lepton polarization in $K_L \to μ…
The decay $b\to sν\barν$ is discussed in the minimal supersymmetric standard model with general flavor mixing for squarks, at large $\tanβ$. In this case, in addition to the chargino loop contributions which were analyzed in previously studies, $\tanβ$-enhanced contributions from the gluino and charged Higgs boson loops might become sizable compared with the standard model contribution, at least in principle. However, it is demonstrated that the experimental bounds on the new physics contributions to the radiative decay $b\to sγ$ should strongly constrain these contributions to $b\to sν\barν$,…
Study of the MSSM in large tan$β$ regime has to include correlations between the constraints presented by the low energy values of the b quark mass and BR($b \to sγ$). Both quantities receive SUSY contributions enhanced by tan$β$ and have a major impact on the MSSM analysis. Here we summarize the results of such a study constrained by a complete SO(10) model. The dominant effects to the analysis come from third generation Yukawa couplings and a GUT threshold to $α_s$. We show that a small negative GUT correction to $α_s$ accommodates $α_s(M_Z) \leq 0.118$ and $δm_b^{SUSY} > 0$. The latter quan…
We consider the infrared quasi fixed point solutions of the renormalization group equations for the Yukawa couplings and soft supersymmetry breaking parameters in the MSSM in the \underline{large $\tanβ$} regime. The existence of IR quasi fixed points together with the values of gauge couplings, third generation quarks, lepton and Z-boson masses allows one to predict masses of the Higgs bosons and SUSY particles as functions of the only free parameter, $m_{1/2}$, or the gluino mass. The lightest Higgs boson mass for $M_{SUSY} \approx 1$ TeV is found to be $m_h=128.2-0.4-7.1 \pm 5$ GeV for $μ>0…
We apply the effective field theory definition of Minimal Flavour Violation (MFV) to the MSSM. We explicitly show how, by this definition, the new sources of flavour and CP violation present in the MSSM become functions of the SM Yukawa couplings, and cannot be simply set to zero, as is common wisdom in phenomenological MSSM studies that assume MFV. We apply our approach to the MSSM Delta B = 2 Hamiltonian at low tan(beta). The limit of MFV amounts to a striking increase in the predictivity of the model. In particular, SUSY corrections to meson-antimeson mass differences Delta M(d,s) are alway…
We study the production of a heavy CP-odd $A^0$ boson in association with a photon $e^+e^-\to A^0γ$ and a Z boson $e^+e^-\to A^0 Z$ as well as the single production of $A^0$ via $e^+e^- \to ν_e\barν_e A^0$ in the MSSM with CP violating phases. In the case of $e^+e^-\to A^0γ/ A^0 Z$, we show that the squark contribution, which vanishes in the MSSM with real parameters, turns out to be sizeable in presence of CP violating phases in the soft SUSY parameters. For $e^+e^- \to ν_e \barν_e A^0$ in both the 2HDM and MSSM with real parameters, the cross section does not reach observable rates at a NLC.…
Within the minimal supersymmetric standard model (MSSM), the large tan(beta) regime can lead to important modifications in the pattern of CP-violating sources contributing to low energy electric dipole moments (EDMs). In particular, four-fermion CP-violating interactions induced by Higgs exchange should be accounted for alongside the constituent EDMs of quarks and electrons. To this end, we present a comprehensive analysis of three low energy EDM observables - namely the EDMs of thallium, mercury and the neutron - at large tan(beta), in terms of one- and two-loop contributions to the constitue…
Supersymmetric loop contributions can lead to different decay rates of H+\to t\bar b and H-\to b\bar t. We calculate the decay rate asymmetry δ^CP = \frac{Γ(H+\to t\bar b)-Γ(H-\to b\bar t)}{{Γ(H+\to t\bar b)+Γ(H-\to b\bar t)} at next-to-leading order in the MSSM with complex parameters. We analyse the parameter dependence of δ^CP with emphasis on the phases of A_t and A_b. It turns out that the most important contribution comes from the loop with stop, sbottom, and gluino. If this contribution is present, δ^CP can go up to 10-15% for tan(beta)~10, and to ~5% for large values of tan(beta).
In the Minimal Supersymmetric Standard Model (MSSM) searches for the heaviest CP-even and CP-odd Higgs $H$, $A$ to tau-lepton pairs severely constrain the parameter region for large values of $\tanβ$ and light Higgs bosons $H$, $A$. We demonstrate how the experimental constraint can be avoided by new decays to light third-generation sfermions, whose left-right couplings to $H$ can be maximised in regions of large trilinear couplings $A_{b}$, $A_τ$ for sbottoms and staus, or large supersymmetric (SUSY) Higgs mass $μ$ for stops. Due to the $\tanβ$-enhancement in the production cross-sections via…
We propose two new benchmark scenarios for Higgs-boson searches in the Minimal Supersymmetric Standard Model (MSSM). These scenarios are specifically designed for the low $\tanβ$ region. A light Higgs-boson mass prediction compatible with the observed value of $125$ GeV is ensured in almost the entire parameter space by employing a flexible supersymmetric (SUSY) mass scale, reaching values of up to $10^{16}$ GeV. The MSSM Higgs-sector predictions are evaluated in an effective field theory (EFT) framework that exhibits a Two-Higgs-Doublet-Model at the low scale. In the first scenario all SUSY p…
The region of MSSM Higgs parameter space currently excluded by the CDF Collaboration, based on an analysis of ~1 fb^-1 of integrated luminosity, is less than the expected sensitivity. We analyze the potential implications of the persistence of this discrepancy within the MSSM, assuming that the soft supersymmetry-breaking contributions to scalar masses are universal, apart from those to the Higgs masses (the NUHM model). We find that a light heavy MSSM Higgs signal in the unexcluded part of the sensitive region could indeed be accommodated in this simple model, even after taking into account o…
Within the minimal supersymmetric extension of the Standard Model (MSSM) the associated production of neutral Higgs bosons with top and bottom quarks belongs to the most important Higgs-boson production processes at the LHC. At large values of tan(beta), in particular, bottom--Higgs associated production constitutes the dominant production channel within the MSSM. We have calculated the next-to-leading-order supersymmetric QCD corrections to neutral Higgs production through the parton processes q qbar, gg -> t tbar / b bbar + h/H/A and present results for the total cross sections. The genuine …
It is well known that the Minimal Supersymmetric Standard Model (MSSM) can enhance Br[B_{d,s}->mu^+ mu^-] by orders of magnitude, even if we assume the Cabibbo-Kobayashi-Maskawa (CKM) matrix to be the only source of flavour violation. Of particular interest is the quantity R=Br[B_d->mu^+ mu^-]/Br[B_s->mu^+ mu^-], since (i) the theoretical errors cancel to a large extent, and (ii) it offers a theoretically clean way of extracting the ratio |V_{td}/V_{ts}| in the Standard Model, which predicts R_SM ~ |V_{td}/V_{ts}|^2 \~ O(10^{-2}). Exploring three different scenarios of modified minimal flavour…
We present results for the SM and MSSM Higgs-boson production cross sections at the Tevatron and the LHC. The SM cross sections are a compilation of the state-of-the-art theoretical predictions. The MSSM cross sections are obtained from the SM ones by means of an effective coupling approximation, as implemented in FeynHiggs. Numerical results have been obtained in four benchmark scenarios for two values of tan beta, tan beta = 5, 40.
Recently it has been understood that flavor-changing processes mediated by Higgs bosons could be a new and powerful tool for discovering supersymmetry. In this paper we show that they may also provide an important method for constraining the parameters of the minimal supersymmetric standard model (MSSM). Specifically, we show that observation of B_s -> mu mu at the Tevatron implies a significant, model-independent lower bound on tan(beta) in the MSSM. This is very important because tan(beta) enters crucially in predictions and interpretations of the MSSM, though it is difficult to measure. Wit…
We analyze the Tevatron reach for neutral Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM), using current exclusion limits on the Standard Model Higgs. We study four common benchmark scenarios for the soft supersymmetry-breaking parameters of the MSSM, including cases where the Higgs decays differ significantly from the Standard Model, and provide projections for the improvements in luminosity and efficiency required for the Tevatron to probe sizeable regions of the $(m_A, \tanβ)$ plane.
We present a MSSM study of the b -> s gamma decay in a Minimal Flavor Violating (MFV) framework, where the form of the soft SUSY breaking terms is determined by the Standard Model Yukawa couplings. In particular, we address the role of gluino contributions, which are set to zero in most studies of the MFV MSSM. Gluino contributions can play an important role in the MFV MSSM whenever mu * tan(beta) is large. In fact, similarly to chargino contributions, gluino contributions are tan(beta) enhanced and can easily dominate charged Higgs contributions for large values of tan(beta). Even though each…
The search for MSSM Higgs bosons will be an important goal at the LHC. In order to analyze the search reach of the CMS experiment for the charged MSSM Higgs bosons, we combine the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of MSSM Higgs-boson production and decay properties. The experimental analyses are done assuming an integrated luminosity of 30 fb^-1 for the two cases M_H+- < m_t and M_H+- > m_t. The results are interpreted as 5 sigma discovery contours in M_H+- - tan_beta planes of the MSSM for vario…
The generalization of the MSSM to the case of four chiral fermion generations (4GMSSM) can lead to significant changes in the phenomenology of the otherwise familiar Higgs sector. In most of the 3GMSSM parameter space, the lighter CP-even $h$ is $\sim 115-125$ GeV and mostly Standard Model-like while $H,A,H^\pm$ are all relatively heavy. Furthermore, the ratio of Higgs vevs, $\tan β$, is relatively unconstrained. In contrast to this, in the 4GMSSM, heavy fourth generation fermion loops drive the masses of $h,H,H^\pm$ to large values while the CP-odd boson, $A$, can remain relatively light and …
We give an extensive description of the renormalisation of the Higgs sector of the minimal supersymmetric model in SloopS. SloopS is an automatised code for the computation of one-loop processes in the MSSM. In this paper, the first in a series, we study in detail the non gauge invariance of some definitions of tan(beta). We rely on a general non-linear gauge fixing constraint to make the gauge parameter dependence of different schemes for tan(beta) at one-loop explicit. In so doing, we update, within these general gauges, an important Ward-Slavnov-Taylor identity on the mixing between the pse…
We report on how a straightforward (albeit technically involved) analytic study of the 1-loop effective potential in the Minimal Supersymmetric Standard Model, modifies the usual electroweak symmetry breaking conditions involving $\tan β$ and the other free parameters of the model. The study implies new constraints which (in contrast with the existing ones like $1 \leq \tan β\leq m_t/m_b$) are fully model-independent and exclude more restrictively a region around $\tan β\sim 1$. Further results of this study will be only touched upon here.
We study the Higgs sector of supersymmetric models containing two Higgs doublets with a light MSSM-like CP odd Higgs, $m_A \lesssim 10$ GeV, and $\tan β\lesssim 2.5$. In this scenario all Higgses resulting from two Higgs doublets: light and heavy CP even Higgses, $h$ and $H$, the CP odd Higgs, $A$, and the charged Higgs, $H^\pm$, could have been produced at LEP or the Tevatron, but would have escaped detection because they decay in modes that have not been searched for or the experiments are not sensitive to. Especially $H \to ZA$ and $H^\pm \to W^{\pm \star} A$ with $A \to c \bar c, τ^+ τ^-$ …
The status of the evaluation of the MSSM Higgs sector is reviewed. The phenomenological impact of recently obtained corrections is discussed. In particular it is shown that the upper bound on m_h within the MSSM is shifted upwards. Consequently, lower limits on tan beta obtained by confronting the upper bound as function of tan beta with the lower bound on m_h from Higgs searches are significantly weakened. Furthermore, the region in the M_A-tan beta-plane where the coupling of the lightest Higgs boson to down-type fermions is suppressed is modified. The presently not calculated higher-order c…
We show that the upper bound on the lightest Higgs mass in the MSSM is relaxed by introducing a singlet which couples to the Higgs fields, even at a large tan beta region, preferable for explaining the muon anomalous magnetic moment. In the models of a singlet extension, it is known that the upper bound is relaxed by a tree-level contribution, especially at small tan beta region. For large tan beta, however, the requirement for the perturbativity on the singlet-Higgs coupling up to the GUT scale prevents the lightest Higgs from obtaining a large tree-level mass. We construct an explicit UV com…
In various unified extensions of the Minimal Supersymmetric Standard Model, the Yukawa couplings of the third generation are predicted to be of the same order. As a result, low energy measured mass ratios, require large ratios of the standard model Higgs vacuum expectation values, corresponding to a large value of the parameter $tanβ$. We present analytic solutions for the Yukawa couplings and the Higgs and third generation squark masses, in the case of large top and bottom Yukawa couplings. We examine regions of these Yukawas which give predictions for the top mass compatible with the present…
In this paper we analyze the process $B_s \to \ell^+ \ell^-$ in a model II 2HDM and MSSM. All the leading terms of Wilson coefficients relevant to the process are given in the large tan$β$ limit. It is shown that the decay width for $B_s \to \ell^+ \ell^-$ depends on all parameters except $m_{A^0}$ in the 2HDM. The branching ratio of $B_s \to μ^+ μ^-$ can reach its experimental bound in some large tan$β$ regions of the parameter space in MSSM because the amplitude increases like tan$^3β$ in the regions. For l=$τ$, the branching ratio can even reach $10^{-4}$ in the regions. Therefore, the expe…
One loop contributions to the CP even-CP odd Higgs boson mixings arising from contributions due to exchange of a vectorlike multiplet are computed under the Higgs boson mass constraint. The vectorlike multiplet consists of a fourth generation of quarks and a mirror generation. This sector brings in new CP phases which can be large consistent with EDM constraints. In this work we compute the contributions from the exchange of quarks and mirror quarks $t_{4L}, t_{4R}, T_{L}, T_{R}$, and their scalar partners, the squarks and the mirror squarks. The effect of their contributions to the Higgs boso…
We complete the effective potential calculation of the two-loop, top/bottom Yukawa corrections to the Higgs boson masses in the Minimal Supersymmetric Standard Model, by computing the O(at^2 + at*ab + ab^2) contributions for arbitrary values of the bottom Yukawa coupling. We also compute the corrections to the minimization conditions of the effective potential at the same perturbative order. Our results extend the existing O(at^2) calculation, and are relevant in regions of the parameter space corresponding to tan(beta) >> 1. We extend to the Yukawa corrections a convenient renormalization sch…
