We present a full diagrammatic computation of the one-loop corrections from the neutrino/sneutrino sector to the renormalized neutral CP-even Higgs boson self-energies and the lightest Higgs boson mass, Mh, within the context of the so-called MSSM-seesaw scenario. This consists of the Minimal Supersymmetric Standard Model with the addition of massive right handed Majorana neutrinos and their supersymmetric partners, and where the seesaw mechanism is used for the lightest neutrino mass generation. We explore the dependence on all the parameters involved, with particular emphasis in the role played by the heavy Majorana scale. We restrict ourselves to the case of one generation of neutrinos/sneutrinos. For the numerical part of the study, we consider a very wide range of values for all the parameters involved. We find sizeable corrections to Mh, which are negative in the region where the Majorana scale is large (10^{13}-10^{15} GeV) and the lightest neutrino mass is within a range inspired by data (0.1-1 eV). For some regions of the MSSM-seesaw parameter space, the corrections to Mh are substantially larger than the anticipated Large Hadron Collider precision.
Supersymmetric models with broken R-parity provide mechanisms that allow to generate Majorana neutrino masses and magnetic moments through virtual particle-sparticle loops. This constitutes an attractive alternative to the see-saw mechanism. In this paper we present a detailed calculation of the transition magnetic moments of a Majorana neutrino in gauge mediated supersymmetry breaking MSSM without R-parity. We base our analysis on the renormalization group evolution of the MSSM parameters, which are unified at the GUT scale.
We study the effects of heavy Majorana neutrinos on the Higgs sector of the MSSM via radiative corrections. We work within the SUSY context where the MSSM particle content is enlarged with right handed neutrinos and their corresponding SUSY partners, the sneutrinos, and where compatibility with neutrino data is required. We compute the one-loop corrections to the mass of the lightest MSSM CP-even neutral Higgs boson from Majorana neutrinos and their SUSY partners and assume a seesaw mechanism of type I for neutrino mass generation. A negative and sizeable Higgs mass correction of up to -5 GeV …
We review the main results of the one-loop radiative corrections from the neutrino/sneutrino sector to the lightest Higgs boson mass, M_h, within the context of the so-called MSSM-seesaw scenario where right handed neutrinos and their supersymmetric partners are included in order to explain neutrino masses. For simplicity, we have restricted ourselves to the one generation case. We find sizable corrections to M_h, which are negative in the region where the Majorana scale is large (10^{13} - 10^{15} GeV) and the lightest neutrino mass is within a range inspired by data (0.1 - 1 eV). For some re…
We explore the possibility of distinguishing the SM-like MSSM Higgs boson from the SM Higgs boson via Higgs boson pair production at future muon collider. We study the behavior of the production cross section in SM and MSSM with Higgs boson mass for various choices of MSSM parameters tan βand m\sub A. We observe that at fixed CM energy, in the SM, the total cross section increases with the increase in Higgs boson mass whereas this trend is reversed for the MSSM case. The changes that occur for the MSSM case in comparison to the SM predictions are quantified in terms of the relative percentage …
The corrections to the MSSM Higgs boson masses and couplings performed in this millennium are briefly reviewed. For the lightest MSSM Higgs boson mass, m_h, we list the current status of the intrinsic uncertainties (due to unknown higher-order corrections) and the parametric uncertainties (due to the imperfect experimental knowledge of the input parameters). The need for high-precision calculations in the MSSM Higgs boson sector is exemplified in a realistic example.
Starting with the two-loop effective potential of the MSSM, and assuming a supersymmetric scale well above $M_Z$, we derive a simple analytical approximation for the lightest CP-even Higgs boson mass including resummation of higher order logarithmic terms via RG-improvement and finite non-logarithmic terms up to ${\cal O}(α_sα_t)$. This formula describes the most relevant radiative corrections to the MSSM Higgs boson mass, in particular, those associated with non-zero top-squark mixing.
Different approaches are used for the calculation of the SM-like Higgs boson mass in the MSSM: the fixed-order diagrammatic approach is accurate for low SUSY scales; the EFT approach,for high SUSY scales. Hybrid approaches, combining fixed-order and EFT calculations, allow to obtain a precise prediction also for intermediary SUSY scales. Here, we briefly discuss the hybrid approach implemented into the code FeynHiggs. In addition, we show how the refined Higgs mass prediction was used to define new MSSM Higgs benchmark scenarios.
We briefly review the phenomenological implications of the minimal supersymmetric standard model (MSSM) with explicit radiative breaking of CP invariance in the Higgs sector for the LEP2 and Tevatron colliders.
The high precision measurements of the Higgs mass and couplings at the future Higgs factories are sensitive to the parameter space of the Minimal Supersymmetric Standard Model (MSSM). Focused on the dominant stop sector contributions, we study the implication of the Higgs precision measurements on MSSM using multi-variable $χ^2$ fit. The results show nice complementarity between the indirect searches at Higgs factories and the direct searches at the current LHC program.
In this work, we study the implication of Higgs precision measurements at future Higgs factories on the MSSM parameter space, focusing on the dominant stop sector contributions. We perform a multi-variable fit to both the signal strength for various Higgs decay channels at Higgs factories and the Higgs mass. The chi-square fit results show sensitivity to mA, tan beta, stop mass parameter mSUSY as well as the stop left-right mixing parameter Xt. We also study the impact of the Higgs mass prediction on the MSSM and compare the sensitivities of different Higgs factories.
We demonstrate how CP violation manifests itself in the Higgs sector of the minimal supersymmetric extension of the Standard Model (MSSM). Starting with a brief introduction to CP violation in the MSSM and its effects on the Higgs sector, we discuss some phenomenological aspects of the Higgs sector CP violation based on the two scenarios called CPX and Trimixing
The structure of the Higgs sector in the minimal supersymmetric standard model is reviewed at the one-loop level. An on-shell renormalization scheme of the MSSM Higgs sector is presented in detail together with the complete list of formulae for the neutral Higgs masses at the one-loop level. The results of a complete one- loop calculation for the mass spectrum of the neutral MSSM Higgs bosons and the quality of simpler Born-like approximations are discussed for sfermion and gaugino masses in the range of the electroweak scale.
The implications of the LHC SUSY searches as well as the discovery of a new bosonic state compatible with the lightest Higgs boson will be discussed in the context of constrained and general MSSM scenarios. Exploring the MSSM through the Higgs sector is an alternative and complementary path to direct searches, and tight constraints on the MSSM parameter space can be obtained.
I summarize results of two-loop effective potential calculations of the lightest CP-even Higgs boson mass in the minimal supersymmetric standard model.
The effective potential in the MSSM at the one-loop level is used to evaluate masses of the neutral Higgs scalars and to study finite-temperature phase transition. The CP violation in the Higgs sector, which is induced by the spontaneous mechanism or by the complex parameters in the MSSM through radiative corrections, is determined at zero and finite temperatures.
We show that large ($> 100$ GeV) mass splittings between the charged Higgs boson ($H^\pm$) and the neutral Higgs bosons ($H^0$ and $A^0$) are possible in the Minimal Supersymmetric Standard Model (MSSM). Such splittings occur when the $μ$ parameter is considerably larger than the common SUSY scale, $M_{SUSY}$, and have significant consequences for MSSM Higgs searches at future colliders.
The theoretical predictions in the MSSM for Higgs-boson production at a future e^+e^- Linear Collider and Higgs-boson decay processes are discussed focusing in particular on recent diagrammatic two-loop results in the MSSM Higgs sector. The present status of the theoretical predictions is briefly summarized, and it is emphasized that considerable improvements will be necessary in order to match the high experimental accuracy achievable at a future Linear Collider.
The theoretical structure of the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM) is briefly described. An outline of Higgs phenomenology at future lepton colliders is presented, and some opportunities for probing the physics of the MSSM Higgs sector at an e-e- collider are considered.
The LEP era has brought immense progress in searches for Higgs bosons over the last 12 years which will guide searches at future colliders. The evolution of the Higgs boson mass limits are reviewed with the focus on results from general parameter scans in the Minimal Supersymmetric extension of the Standard Model (MSSM) in contrast to the so-called benchmark limits. The hint for a Standard Model (SM) Higgs boson of 115.6 GeV can also be interpreted as a preference for a Higgs boson of that mass in the MSSM. Further small data excesses allow the hypothesis that the neutral Higgs bosons of the M…
In this contribution a brief review about the status of higher order corrections to Higgs boson production within the Minimal Supersymmetric Standard Model (MSSM) is given. Furthermore the first activities towards third-order corrections in the Standard Model (SM) are discussed.
We consider the effects of a fourth generation of chiral fermions within the MSSM. Such a model offers the possibility of having the lightest neutral Higgs boson significantly heavier than in the three generation MSSM. The model is highly constrained by precision electroweak data, along with Higgs searches at the Tevatron. In addition, the requirements of perturbative unitarity and direct searches for heavy quarks imply that the four generation MSSM is only consistent for tan beta ~ 1 and highly tuned 4th generation fermion masses.
We present a comprehensive analysis on the MSSM Higgs sector CP violation at photon colliders including the chargino contributions as well as the contributions of other charged particles. The chargino loop contributions can be important for the would-be CP odd Higgs production at photon colliders. Polarization asymmetries are indispensable in determining the CP properties of neutral Higgs bosons.
We study the prospects for distinguishing the CP-even Higgs boson of the minimal supersymmetric extension of the Standard Model (MSSM) from the Standard Model (SM) Higgs boson by measuring its branching ratios at an e+e- linear collider. The regions of the M_A - tan beta plane in which an MSSM Higgs boson can be distinguished from the SM Higgs boson depend strongly upon the supersymmetric parameters that enter the radiative corrections to the Higgs mass matrix and the Higgs couplings to fermions. In some regions of parameter space it is possible to extract the supersymmetric correction to the …
In the framework of the effective field theory approach to heavy supersymmetry radiative corrections in the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM) for the effective potential decomposition up to the dimension-six operators are calculated. Symbolic expressions for the threshold corrections induced by $F$- and $D$- soft supersymmetry breaking terms are derived and the Higgs boson mass spectrum respecting the condition $m_h=$125 GeV for the lightest $CP$-even scalar is evaluated.
This lecture discusses the Higgs boson sectors of the SM and the MSSM, in particular in view of the recently discovered particle at \sim 125.5 GeV. It also covers their connection to electroweak precision physics and the implications for the consistency tests of the respective model.
The problems of Standard Model as well as questions related to Higgs boson properties led to the need for modeling of ttH associated production and Higgs boson decay to top quark pair within the MSSM model. With the help of computer programs MadGraph, Pythia and Delphes and using the latest kinematic cuts taken from experimental data obtained at the LHC we predicted the masses of MSSM Higgs bosons, A and H.
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…
Some possibilities to test the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM) at the LHC and future $e^+e^-$ colliders are discussed. This includes precision coupling strength measurements, the search for additional Higgs bosons as well as their decay to supersymmetric particles.
We discuss a few new characteristic features of the loop-induced MSSM Higgs-sector CP violation at the LHC based on two scenarios: (i) CPX and (ii) Trimixing.
HFOLD (Higgs Full One Loop Decays) is a Fortran program package for calculating all MSSM Higgs two-body decay widths and the corresponding branching ratios at full one-loop level. The package is done in the SUSY Parameter Analysis convention and supports the SUSY Les Houches Accord input and output format.
Diagrammatic two-loop results are presented for the leading QCD corrections to the masses of the neutral CP-even Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM). The results are valid for arbitrary values of the parameters of the Higgs and scalar top sector of the MSSM. Their impact on a precise prediction for the mass of the lightest Higgs boson is briefly discussed.
We consider the measurement of the trilinear couplings of the neutral Higgs bosons~($H^0, h^0$) in the minimal supersymmetric standard model~(MSSM) at a high energy $e^+$ $e^-$ linear collider in the light of the discovery of a Higgs boson at the CERN Large Hadron Collider~(LHC). We identify the state observed at the LHC with the lightest CP-even Higgs boson of the MSSM. We implement this constraint, as well as all the other relevant experimental constraints, on the parameter space of the MSSM in order to study the feasibility of measuring the trilinear couplings of the neutral Higgs bosons. F…
These lectures were presented at the TASI 2012 summer school to a mixture of graduate students in particle theory and cosmology. They serve as an elementary introduction to the Minimal Supersymmetric Standard Model (MSSM) and discuss the implications of a 125 GeV Higgs boson for this theory. Some familiarity with the Standard Model is assumed.
We present the latest version 2.6 of FeynHiggs, a program for computing MSSM Higgs-boson masses and related observables, such as mixing angles, branching ratios, and couplings, including state-of-the-art higher-order contributions. The most important new feature is the inclusion of the fully complex O(α_tα_s) two-loop corrections, which enables FeynHiggs to give the most precise Higgs-mass evaluation in the complex MSSM in the Feynman-diagrammatic approach to date.
In this paper we discuss the production of a heavy scalar MSSM Higgs boson H and its subsequent decays into pairs of electroweak gauge bosons WW and ZZ. We perform a scan over the relevant MSSM parameters, using constraints from direct Higgs searches and several low-energy observables. We then compare the possible size of the pp -> H -> WW,ZZ cross sections with corresponding Standard Model cross sections. We also include the full MSSM vertex corrections to the H -> WW,ZZ decay and combine them with the Higgs propagator corrections, paying special attention to the IR-divergent contributions. W…
The discovery potential of the ATLAS experiment at the LHC for Higgs bosons of the MSSM is discussed. Several CP conserving and one CP violating benchmark scenario are investigated.
Various aspects of the Higgs boson phenomenology of the Minimal Supersymmetric Standard Model (MSSM) are reviewed. Emphasis is put on the effects of higher-order corrections. The masses and couplings are discussed in the MSSM with real and complex parameters. Higher-order corrections to Higgs boson production channels at a prospective e+ e- linear collider are investigated. Corrections to Higgs boson decays to SM fermions and their phenomenological implications for hadron and lepton colliders are explored.
A short review of the theory and phenomenology of Higgs bosons is given, with focus on the Standard Model (SM) and the minimal supersymmetric extension of the Standard Model (MSSM). The potential for Higgs boson discovery at the Tevatron and LHC, and precision Higgs studies at the LHC and a future e+e- linear collider are briefly surveyed. The phenomenological challenge of the approach to the decoupling limit, where the properties of the lightest CP-even Higgs boson of the MSSM are nearly indistinguishable from those of the SM Higgs boson is emphasized.
We propose a new mechanism for producing a Higgs boson mass near 125 GeV within the MSSM. By coupling the MSSM Higgs boson to a set of strongly interacting fields, large corrections to the Higgs quartic coupling are induced. Although the Higgs doublets do not participate in the strong dynamics, they feel the effects of the strongly coupled sector via (semi-)perturbative interactions. These same strong dynamics are also capable of generating the $μ$-term. Additionally, this strong sector is in the conformal window, which drives the couplings to an infrared fixed point and naturally generates mo…
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.
Adopting a recently proposed single-superfield framework of supergravity inflation, we consider large field inflationary models in which MSSM Higgs-like fields play the role of the inflaton. In the simplest cases, the inflaton potential has a fractional power, which is different from that of the original Higgs inflation, and it can be tested by cosmological observations in near future. We find difficulties in identifying the inflaton with the MSSM Higgses and discuss possible candidates of the inflaton.
This work provides an elementary introduction to the Higgs sector renormalisation within the Minimal Suppersymmetric Standard Model (MSSM) framework. The MSSM tree-level relation $m_h^2+m_H^2=m_A^2+m_Z^2$ is renormalised using the standard technique of direct computation of the relevant one-loop Feynman diagrams. The expected cancellation of ultraviolet divergences is explicitly checked and the well-known leading-log term is recovered.
We interpret the current experimental limit on the lightest Higgs boson mass to suggest that if nature is supersymmetric, there are additional interactions beyond those of the MSSM coming from new degrees of freedom around the TeV scale. Within an effective field theory analysis, the leading order corrections to the MSSM are described in terms of only two operators. This provides a highly constrained description of Beyond MSSM (BMSSM) physics. The scalar Higgs spectrum as well as the chargino and neutralino spectrum and couplings are modified in a distinctive way. These operators can be genera…
In the Minimal Supersymmetric Standard Model (MSSM) with three generations of fermions, there is a stringent upper bound on the mass of the lightest neutral Higgs h, and the mass of the charged Higgs H^+, must be close (within tens of GeV) to the heavier neutral Higgs, H, and the pseudoscalar Higgs A. In this Brief Report, we show that in the four generation MSSM, the upper bound on the h mass is much higher, as high as 400 GeV, and H^+ is generally much heavier than the A, allowing the H^+ -> A W^+ decay, potentially changing search strategies for both the charged Higgs and the pseudoscalar. …
We show how the imaginary parts of the Higgs-Boson self-energies in the MSSM are consistenly taken into account in the Higgs-Boson mass determination. In a numerical example we find effects of 5 GeV in the mass difference of the two heavy neutral Higgs bosons. The imaginary contributions have been included into the code FeynHiggs.
We study the effect of explicit CP violation in the Higgs sectors of the MSSM in the di-photon decay of the lightest CP-mixed Higgs state. Further it is shown that the gluon fusion production mechanism along with the di-photon decay enhances CP-violating effects for a large set of suitably chosen parameter values.
It is often argued that low fine tuning in the MSSM necessarily requires a rather light Higgsino. In this note we show that this need not be the case when a more complete set of soft SUSY breaking mass terms are included. In particular an Higgsino mass term, that correlates the $μ-$term contribution with the soft SUSY-breaking Higgsino masses, significantly reduces the fine tuning even for Higgsinos in the TeV mass range where its relic abundance means it can make up all the dark matter.
In the Minimal Supersymmetric Standard Model (MSSM) we calculate the corrections to neutral CP-even Higgs-boson production in the WW-fusion and Higgs-strahlung channel, e+e- -> \bar nu nu {h,H}, at a future Linear Collider, taking into account all O(alpha) corrections arising from loops of fermions and sfermions. For the production of the lightest MSSM Higgs boson, h, we find genuine loop corrections (beyond the universal Higgs propagator corrections) of up to -5%. For the heavy CP-even neutral Higgs boson, H, which shows decoupling behavior at tree level, we find non-negligible corrections th…
Final results from the MSSM Higgs boson searches from the LEP experiments ALEPH, DELPHI, L3 and OPAL are presented. The results are statistically combined and the statistical significance for signal and background hypotheses are given. Upper bounds on the production cross sections are set for several Higgs-like topologies. Interpretations for six benchmark scenarios in the MSSM, both for CP-conserving and CP-violating scenarios, are given. Limits on the tan(beta) parameter, and in some scenarios upper limits on the neutral Higgs boson masses are set.
An accurate determination of the Higgs decay branching ratios to bb, cc, gg, WW* and tau tau pairs is important for the study of the Higgs couplings and for determining its SM or MSSM nature in the mass range 100 GeV/c2 < M_H < 140 GeV/c^2. This measurement also represents an important benchmark for the optimisation of the detector design. The accuracy on the determination of the Higgs decay branching ratio to fermions and WW* pairs has been studied using the simulation of the detector designed for the TESLA e+e- linear collider at c.m. energy of 350 GeV and 500 GeV. The results are discussed …
In the Minimal Supersymmetric Standard Model (MSSM), the bottom Yukawa coupling of the Higgs boson can considerably deviate from its Standard Model prediction due to non-decoupling effects. We point out that the ratio of the Higgs boson decay branching fraction to a bottom quark pair and that to a $W$-boson pair from the same production channel is particularly sensitive to large additional MSSM Higgs boson mass regions at future electron-positron colliders. Based on this precision measurement, we explicitly show the indirect discovery reach of the additional Higgs bosons according to planned p…
We review that the heavy CP-even MSSM Higgs boson is still a viable candidate to explain the Higgs signal at 125 GeV. This is possible in a highly constrained parameter region, that will be probed by LHC searches for the CP-odd Higgs boson and the charged Higgs boson in the near future. We briefly discuss the new benchmark scenarios that can be employed to maximize the sensitivity of the experimental analysis to this interpretation.
We describe the implementation of the two-loop Higgs-mass corrections of $\mathcal{O}{\left(α_t^2\right)}$ in the complex MSSM in $\tt{FeynHiggs}$. The program for the calculation is included in $\tt{FeynHiggs}$ and documented here in some detail such that it can be re-used as a template for similar calculations.
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…
The search for MSSM Higgs bosons will be an important goal at the LHC. We analyze the search reach of the CMS experiment for the heavy neutral MSSM Higgs bosons with an integrated luminosity of 30 or 60 fb^-1. This is done by combining the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The results are interpreted in MSSM benchmark scenarios in terms of the parameters tan_beta and the Higgs-boson mass scale, M_A. We study the dependence of the 5 sigma discovery contours in the M…
We take a step towards a complete NLO-QCD determination of the production of a pair of Higgs scalars in the MSSM. Exploiting a low-energy theorem that connects the Higgs-gluon interactions to the derivatives of the gluon self-energy, we obtain analytic results for the one- and two-loop squark contributions to Higgs pair production in the limit of vanishing external momenta. We find that the two-loop squark contributions can have non-negligible effects in MSSM scenarios with stop masses below the TeV scale. We also show how our results can be adapted to the case of Higgs pair production in the …
The prospects for central exclusive diffractive (CED) production of MSSM Higgs bosons at the LHC are reviewed. It is shown that the CED channels, making use of forward proton detectors at the LHC installed at 220 m and 420 m distance around ATLAS and / or CMS, can provide important information on the Higgs sector of the MSSM. In particular, CED production of the neutral CP-even Higgs bosons h and H and their decays into bottom quarks has the potential to probe interesting regions of the M_A--tan_beta parameter plane of the MSSM and may give access to the bottom Yukawa couplings of the Higgs bo…
