Within the minimal supersymmetric extension of the Standard Model, the mass of the light CP-even Higgs boson is computed to three-loop accuracy, taking into account the next-to-next-to-leading order effects from supersymmetric Quantum Chromodynamics. We consider two different scenarios for the mass hierarchies of the supersymmetric spectrum. Our numerical results amount to corrections of about 500 MeV which is of the same order as the experimental accuracy expected at the CERN Large Hadron Collider (LHC).
We study the range of Higgs masses predicted by High-Scale Supersymmetry and by Split Supersymmetry, using the matching condition for the Higgs quartic coupling determined by the minimal field content. In the case of Split Supersymmetry, we compute for the first time the complete next-to-leading order corrections, including two-loop renormalization group equations and one loop threshold effects. These corrections reduce the predicted Higgs mass by a few GeV. We investigate the impact of the recent LHC Higgs searches on the scale of supersymmetry breaking. In particular, we show that an upper b…
In supersymmetry, the Higgs quartic couplings is given by the sum in quadrature of the weak gauge couplings. This leads to the prediction of a light Higgs boson, which still holds when considering loop corrections from soft supersymmetry breaking. However, another source of corrections, which explicitly depends on the scale of the mediation of supersymmetrey breaking, is from generic hard breaking terms. We show that these corrections can significantly modify the Higgs mass prediction in models of low-energy supersymmetry breaking, for example, gauge mediation. Conversely, the Higgs mass measu…
We update our analysis of the Higgs sector masses in Minimal Supersymmetry and in the Two-Higgs Doublet Model to the final ATLAS and CMS data from the 2011-2012 LHC run.
We present here the results for Higgs and Supersymmetry prospective searches at the Large Hadron Collider. We show that for one year at high luminosity, Standard Model and MSSM Higgs should be observed within the theoretically expected mass range. MSUGRA and restricted phenomenological MSSM searches lead to discovery of up to 2.5 TeV squarks and gluinos.
We consider a scenario where supersymmetry is broken at a high energy scale, out of reach of the LHC, but leaves a few fermionic states at the TeV scale. The particle content of the low-energy effective theory is similar to that of Split Supersymmetry. However, the gauginos and higgsinos are replaced by fermions carrying the same quantum numbers but having different couplings, which we call fake gauginos and fake higgsinos. We study the prediction for the light-Higgs mass in this Fake Split SUSY Model (FSSM). We find that, in contrast to Split or high-scale supersymmetry, a 126 GeV Higgs boson…
Possible realistic scenarios are investigated in the minimal supersymmetric standard model (MSSM) Higgs sector extended by dimension-six effective operators. The CP-odd Higgs boson with low mass around 30--90 GeV could be consistently introduced in the regime of large threshold corrections to the effective MSSM two-doublet Higgs potential.
Many models of electroweak symmetry-breaking with an extended Higgs sector exhibit improved naturalness, wherein the new physics scale, at which quadratic divergences of Higgs mass parameters due to top quark loops are cut off, can be pushed beyond the reach of the Large Hadron Collider without unnatural fine tuning. Such models include examples where the new physics is supersymmetry, implying that supersymmetry may still solve the hierarchy problem, even if it eludes detection at the LHC.
The minimal supersymmetric standard model involves a rather restrictive Higgs potential with two Higgs fields. Recently, the full set of classes of symmetries allowed in the most general two Higgs doublet model was identified; these classes do not include the supersymmetric limit as a particular class. Thus, a physically meaningful definition of the supersymmetric limit must involve the interaction of the Higgs sector with other sectors of the theory. Here we show how one can construct basis invariant probes of supersymmetry involving both the Higgs sector and the gaugino-higgsino Higgs intera…
The discovery of a light Higgs boson at the LHC opens a broad program of studies and measurements to understand the role of this particle in connection with New Physics and Cosmology. Supersymmetry is the best motivated and most thoroughly formulated and investigated model of New Physics which predicts a light Higgs boson and can explain dark matter. This paper discusses how the study of the Higgs boson connects with the search for supersymmetry and for dark matter at the LHC and at a future $e^+e^-$ collider and with dedicated underground dark matter experiments.
The observed Higgs boson mass poses a new puzzle in addition to the longstanding problem of the origin of the electroweak scale; the shallowness of the Higgs potential. The Higgs quartic coupling even seems to vanish at around the Planck scale within the uncertainties of the top quark mass and the strong gauge coupling. We show that the shallowness of the Higgs potential might be an outcome of supersymmetry breaking at around the Planck scale. There, the electroweak fine-tuning in the Higgs quadratic terms leads to an almost vanishing quartic coupling at around the Planck scale.
This review provides an elementary discussion of electroweak symmetry breaking in the minimal and the next-to-minimal supersymmetric models with the focus on the fine-tuning problem -- the tension between natural electroweak symmetry breaking and the direct search limit on the Higgs boson mass. Two generic solutions of the fine-tuning problem are discussed in detail: models with unusual Higgs decays; and models with unusual pattern of soft supersymmetry breaking parameters.
Assuming that supersymmetry exists well above the weak scale, we derive the full one-loop matching conditions between the SM and the supersymmetric theory, allowing for the possibility of an intermediate Split-SUSY scale. We also compute two-loop QCD corrections to the matching condition of the Higgs quartic coupling. These results are used to improve the calculation of the Higgs mass in models with high-scale supersymmetry or split supersymmetry, reducing the theoretical uncertainty. We explore the phenomenology of a mini-split scenario with gaugino masses determined by anomaly mediation. Dep…
We summarized our report on leptonic flavor violating Higgs decay into mu + tau under the scheme of a generic supersymmetric standard model without R parity. With known experimental constraints imposed, important combinations of R-parity violating parameters which can give notable branching ratios are listed.
The mass of the Higgs boson in the Split Supersymmetric Standard Model is calculated, including all one-loop threshold effects and the renormalization group evolution of the Higgs quartic coupling through two-loops. The two-loop corrections are very small (<<1 GeV), while the one-loop threshold corrections generally push the Higgs mass down several GeV.
We investigate the stability of the electroweak vacuum for two-Higgs doublet models with a supersymmetric UV completion. The supersymmetry breaking scale is taken to be of the order of the grand unification scale. We first study the case where all superpartners decouple at this scale. We show that contrary to the Standard Model with one Higgs doublet, matching to the supersymmetric UV completion is possible if the low-scale model contains two Higgs doublets. In this case vacuum stability and experimental constraints point towards low values of tan(beta) < 2 and pseudoscalar masses of at least …
We consider a supersymmetric extension of the Standard Model with low-scale supersymmetry breaking. Besides usual superpartners it contains additional chiral goldstino supermultiplet whose scalar components - sgoldstinos can mix with scalars from the Higgs sector of the model. We show that this mixing can have considerable impact on phenomenology of the lightest Higgs boson and scalar sgoldstino. In particular, the latter can be a good candidate for explanation of 2-sigma LEP excess with mass around 98 GeV.
We study the phenomenology of the e-mu lepton flavour violation (LFV) in a general two Higgs Doublet Model (2HDM) including the supersymmetric case. We compute the decay rate expressions of mu -> e gamma, mu -> eee, and mu -> e conversion in nuclei at two loop level. In particular, it is shown that mu -> e gamma is generally the most sensitive channel to probe Higgs-mediated LFV. The correlations among the decay rates of the above processes are also discussed.
Partial Split Supersymmetry with violation of R-parity as a model for neutrino masses is explored. It is shown that at the one-loop level the model can give predictions that are in agreement with all present experimental values for the neutrino sector. An analytical result is that the small solar neutrino mass difference can be naturally explained in the decoupling limit for the heavy Higgs mass eigenstates.
We study the little hierarchy between mass parameters in the Higgs sector and other SUSY breaking masses. This type of spectrum can relieve the fine-tuning problem in the MSSM Higgs sector. Our scenario can be realized by superconformal dynamics. The spectrum in our scenario has significant implications in other phenomenological aspects like the relic abundance of the lightest neutralino and relaxation of the unbounded-from-below constraints.
We present the predictions for the mass $M_h$ of the lightest Higgs boson in models with gauge-mediated supersymmetry breaking as a function of the SUSY-breaking scale. We include all radiative corrections up to two loops and point out that if the CDF e+ e- two-photon event is interpreted in terms of these models, then the lightest Higgs boson should be lighter than 110 GeV.
We study the mass of the lightest Higgs boson in an effective Kaluza-Klein theory with two sources of supersymmetry breaking. When stop mass matrices are non-diagonal with respect to Kaluza-Klein modes and each element is not small in unit of the inverse compactification radius, a very small eigenvalue can be accommodated in the diagonalized basis. We show that in the model with the two sources, the Higgs boson mass can receive suitable corrections for various compactification radii.
We consider orbifold GUTs with N=1 supersymmetry in which the Standard Model (SM) gauge couplings are unified at M_GUT =~ 2 x 10^16 GeV with one of the third family (charged) Yukawa couplings. With split supersymmetry the SM Higgs mass is estimated to be 131 +/- 10 GeV for gauge-top quark Yukawa unification, which increases to 146 +/- 8 GeV for gauge-bottom quark (or gauge-tau lepton) Yukawa unification.
It is generally believed that the low energy effective theory of the minimal supersymmetric standard model is the type 2 two Higgs doublet model. We will show that the type 1 two Higgs doublet model can also as the effective of supersymmetry in a specific case with high scale supersymmetry breaking and gauge mediation. If the other electroweak doublet obtain the vacuum expectation value after the electroweak symmetry breaking, the Higgs spectrum is quite different. A remarkable feature is that the physical Higgs boson mass can 125 GeV unlike in the ordinary models with high scale supersymmetry…
Charged Higgs production in association with staus in electron positron annihilation is a signal of supersymmetry with bilinear R-Parity violation. In this model, neutrino masses and mixing angles are generated due to mixing with neutralinos. We show how parameters related to neutrino physics can be determined at a $500 {\mathrm fb}^{-1}$ Linear Collider from measurements of charged Higgs and stau production cross sections and decay rates. This can be achieved in AMSB where charged Higgs and stau can have similar masses.
The lighter neutral scalar Higgs mass is examined in gauge-mediated supersymmetry-breaking models in which the messenger sector responsible for SUSY breaking is allowed to involve more general sets of $SU(3) \otimes SU(2) \otimes U(1)$ multiplets than those contained in the SU(5) $5 + \bar{5}$ or $10 + \bar{10}$ multiplets. The largest mass for the lighter scalar Higgs is found to be 132 GeV when the breaking parameter $Λ$ is taken to be 100 TeV\@. Thus the predictions for the lightest Higgs mass can be tested at the upgraded Tevatron runs for these general classes of GMSB models.
We consider the effective type-II Two-Higgs doublet model originating from Dirac gaugino models with extended supersymmetry in the gauge sector, which is automatically aligned in the simplest realisations. We show that raising the scale at which the extended supersymmetry is manifest and including quantum corrections actually improves the alignment. Using an effective field theory approach including new threshold corrections and two-loop RGEs, plus two-loop corrections to the Higgs mass in the low-energy theory, we study the implications from the Higgs mass and other experimental constraints o…
ATLAS and CMS report indications of a Higgs boson at M_h 125 GeV. In addition, CMS data show a tenuous bump in the ZZ channel, at about 320 GeV. We make the bold assumption that it might be the indication of a secondary line corresponding to the heaviest scalar Higgs boson of Minimal Supersymmetry, H, and discuss the viability of this hypothesis. We discuss also the case of a heavier H, the relevance of the b bbar decay channel is underlined.
Mirage mediation realized in the Kachru-Kallosh-Linde-Trivedi (KKLT) flux compactification can naturally suppress the up-type Higgs soft mass at low energy scales. As a result, compared to the conventional scenarios, the degree of electroweak fine-tuning can be reduced further up to by a loop factor if the Higgsinos are much lighter than the heavy Higgs doublet. Interestingly, this feature holds even in high-scale supersymmetry as long as the gauge coupling unification, which is required as a prerequisite for mirage mediation, accommodates such light Higgsinos. Under the experimental constrain…
We estimate the upper bound of the Higgs mass and allowed parameter region in the anomaly mediated supersymmetry breaking models. There has been a difficulty that the parameter region cannot be determined precisely in almost SUSY models. However, we succeed to give strict constraints on the parameters from the recent results of the precision measurements of the muon g-2 (anomalous magnetic dipole moment). Especially, the upper bound of the Higgs mass is obtained as a function of only $\tanβ$, and is estimated less than about 123 (GeV) for all the range of $\tanβ<60$ .
We use the most recent data on the Higgs-like resonance h observed at 125 GeV to derive information about the mass of the heavier Higgs particles predicted by Minimal Supersymmetry. We treat as independent parameters the couplings of h to top quark, beauty and massive vector bosons and, in this three dimensional space, we locate the point realizing the best fit to data and compare it to the position of the Standard Model point and to the region of coupling values accommodating heavier Higgs particles in Minimal Supersymmetry. We conclude that mass values 320< M_H< 360 GeV are compatible at 2si…
I present results for the two-loop self-energy functions for neutral and charged Higgs scalar bosons in minimal supersymmetry. The contributions given here include all terms involving the QCD coupling, and those following from Feynman diagrams involving Yukawa couplings and scalar interactions that do not vanish as the electroweak gauge couplings are turned off. The impact of these contributions on the computation of pole masses of the neutral and charged Higgs scalar bosons is studied in a few examples.
We study the explicit CP violation of the Higgs sector in the next--to--minimal supersymmetric model with a gauge singlet Higgs field. Our numerical predictions show that electric dipole moment of electron lies around the present experimental upper limits. The mass of the lightest Higgs boson is quite sensitive to the CP violating phases in the theory. It is observed that as the vacuum expectation value of the singlet gets higher values, CP violation increases.
We quantify the extent to which naturalness is lost as experimental lower bounds on the Higgs boson mass increase, and we compute the natural upper bound on the lightest supersymmetric Higgs boson mass. We find that it would be unnatural for the mass of the lightest supersymmetric Higgs boson to saturate it's maximal upper bound. In the absence of significant fine-tuning, the lightest Higgs boson mass should lie below $120$ GeV, and in the most natural cases it should be lighter than $108$ GeV. For modest $tan β$, these bounds are significantly lower. Our results imply that a failure to observ…
Assuming that the Yukawa couplings between the Higgs and exotic quarks cannot be ignored, we analyze the signals of decay channels $h\rightarrowγγ$ and $h\rightarrow VV^*\;(V=Z,\;W)$ with the Higgs mass around $125\;{\rm GeV}$ in a supersymmetric extension of the standard model where baryon and lepton numbers are local gauge symmetries. Adopting some assumptions on relevant parameter space, we can account for the experimental data on Higgs from ATLAS and CMS naturally.
We present a supersymmetric model of electroweak symmetry-breaking exhibiting improved naturalness, wherein the stop mass can be pushed beyond the reach of the Large Hadron Collider without unnatural fine tuning. This implies that supersymmetry may still solve the hierarchy problem, even if it eludes detection at the LHC.
We examine the possibility of detecting signals of split supersymmetry in the loop-induced decay h --> gamma gamma of the Higgs boson at the Large Hadron Collider, where charginos, as surviving light fermions of the supersymmetric spectrum, can contribute in the loop. We perform a detailed study of uncertainties in various parameters involved in the analysis, and thus the net uncertainty in the standard model prediction of the rate. After a thorough scan of the parameter space, taking all constraints into account, we conclude that it will be very difficult to infer about split supersymmetry fr…
We study in some detail the next-to-minimal supersymmetric standard model with gauge mediation of supersymmetry breaking. We find that it is feasible to spontaneously generate values of the Higgs mass parameters $μ$ and $B_μ$ consistent with radiative electroweak symmetry breaking. The model has a phenomenologically viable particle spectrum. Messenger sneutrinos with mass in the range 6 to 25 TeV can serve as cold dark matter. It is also possible to evade the cosmological domain wall problem in this scenario.
If there are multiple hidden sectors which independently break supersymmetry, then the spectrum will contain multiple goldstini. In this paper, we explore the possibility that the visible sector might also break supersymmetry, giving rise to an additional pseudo-goldstino. By the standard lore, visible sector supersymmetry breaking is phenomenologically excluded by the supertrace sum rule, but this sum rule is relaxed with multiple supersymmetry breaking. However, we find that visible sector supersymmetry breaking is still phenomenologically disfavored, not because of a sum rule, but because t…
The prospects for discovering neutral Higgs bosons in the minimal supersymmetric model (MSSM) and in the minimal supergravity model at the LHC are investigated. Two special discovery channels are discussed: (i) the decay mode of the MSSM CP-odd Higgs boson into photon pairs, and (ii) the decays of neutral Higgs bosons into muon pairs in the MSSM as well as in the minimal supergravity model.
I consider models with non-universal gaugino masses at the gauge coupling unification scale, taking into account the Higgs boson discovery. Viable regions of parameter space are mapped and studied in the case of non-universality following from an F-term in a linear combination of singlet and adjoint representations of SU(5). I consider, in particular, "semi-natural" models that have small μ, with gaugino masses dominating the supersymmetry breaking terms at high energies. Higgsino-like particles are then much lighter than all other superpartners, and the prospects for discovery at the Large Ha…
We analyse hadronically quiet trilepton signatures in the T-parity conserving Littlest Higgs model and in R-parity conserving supersymmetry at the Large Hadron Collider. We identify the regions of the parameter space where such signals can reveal the presence of these new physics models above the Standard Model background and distinguish them from each other, even in a situation when the mass spectrum of the Littlest Higgs model resembles the supersymmetric pattern.
The current LHC results make weak scale supersymmetry difficult due to relatively heavy mass of the discovered Higgs boson and the null results of new particle searches. Geometrical supersymmetry breaking from extra dimensions, Scherk-Schwarz mechanism, is possible to accommodate such situations. A concrete example, the Compact Supersymmetry model, has a compressed spectrum ameliorating the LHC bounds and large mixing in the top and scalar top quark sector with $|A_t|\sim 2m_{\tilde{t}}$ which radiatively raises the Higgs mass. While the zero mode contribution of the model has been considered,…
We studied the extension of Standard Model (SM) Higgs sector with $SU(2)$ triplet and SM gauge singlet in the context of supersymmetry. For a $Z_3$ symmetric superpotential where the singlet field generates the bi-linear Higgs mixing term between two Higgs doublets dynamically. Models like this often have a very light pseudoscalar as pseudo-Nambu Goldstone model of an extra $U(1)$ symmetry. We investigate the possibility of such light hidden Higgs boson with the data of the discovered Higgs boson around 125 GeV. Along with the neutral sector, the charged Higgs bosons in the triplet extended ca…
We study the phenomenology of the mu-tau and e-tau lepton flavour violation (LFV) in a general two Higgs Doublet Model (2HDM) including the supersymmetric case. We consider several LFV decay modes of the charged fermion tau, namely tau-> l_jgamma, tau->l_j l_k l_k and tau-> l_jeta. The predictions and the correlations among the rates of the above processes are computed. In particular, it is shown that tau->l_jgamma processes are the most sensitive channels to Higgs-mediated LFV specially if the splitting among the neutral Higgs bosons masses is not below the 10% level.
We study the breaking of supersymmetry in models with anomalous U(1). These models are simple to construct and contain natural candidates for being the messengers of gauge-mediated supersymmetry breaking. When some of the ordinary matter fields transform under the anomalous U(1), we find a hybrid scenario in which the U(1) and the gauge interactions mediate the breaking of supersymmetry. This leads to a hierarchy of soft masses between the charged and neutral fields and provides a solution to the $μ$-problem. Among these models, we present a scenario in which the Higgs arises as a pseudo-Golds…
We study the $Y=0$ triplet extended supersymmetric model in the light of the recent Higgs boson discovery. We calculate full one loop Higgs mass spectrum in this model where the possible doublet-triplet mixing is considered in the charged Higgs sector. This mixing changes the prediction of $\mathcal{B}r(B_s\to X_s γ)$ in this model, compared to the MSSM. The constraints from the $\sim 125$ GeV Higgs along with $\mathcal{B}r(B_s\to X_s γ)$ are incorporated to find out the allowed parameter space. The lower bounds on the third generation squark masses coming from 125 GeV Higgs are rather week in…
We investigate and compare additional CP-even, CP-odd and charged scalar states appearing in two popular Beyond the Standard Model scenarios. We focus on the simplest possible Higgs sector within warped extra-dimensions and supersymmetry, with the aim to differentiate between them. In each case, we analyze the couplings of the new Higgs states, looking for distinguishing signatures. We show that the couplings of the Standard Model gauge bosons to the first Kaluza-Klein Higgs states of the extra-dimensional setup (CP-even, CP-odd and charged) are very similar to those of the heavy Higgs states …
Precision measurements of the Higgs mass have become a powerful constraint on models of physics beyond the standard model. We revisit supersymmetric models with Dirac gauginos and study the contributions to the Higgs mass. We calculate the leading two-loop corrections to the SM-like Higgs mass by constructing a series of EFTs and iteratively integrating out heavy particles. We then apply these calculations to a variety of scenarios, including a simple Dirac gluino, and split Dirac models of supersymmetry. We present the detailed formulae for threshold corrections and compare with previous resu…
In this letter, we report on lepton flavor violating Higgs decay into mu+tau in the framework of the generic supersymmetric standard model without R parity and list interesting combinations of R-parity violating parameters. We impose other known experimental constraints on the parameters of the model and show our results from the R-parity violating parameters. In our analysis, the branching ratio of Higgs to mu+tau can exceed 10^{-5} within admissible parameter space.
Motivated by the absence, so far, of any direct signal of conventional low-energy supersymmetry, we explore the consequences of making the lightest Higgs boson in supersymmetry relatively heavy, up to about 300 GeV, in the most straightforward way, i.e. via the introduction of a chiral singlet S with a superpotential interaction with the Higgs doublets, λS H_1 H_2. The coupling λdominates over all the other couplings and, to maintain the successful perturbative analysis of the ElectroWeak Precision Tests, is only restricted to remain perturbative up to about 10 TeV. The general features of thi…
Supersymmetric QCD corrections to the gluonic production and decay rate of a CP-even Higgs boson are evaluated at next-to-leading order. To this aim, we derive an effective Lagrangian for the gluon-Higgs coupling. We show that a consistent calculation requires the inclusion of gluino effects, in contrast to what has been done previously. The supersymmetric corrections to the gluon-Higgs coupling lead to a modification of the next-to-leading order K-factor for the Higgs production rate at the LHC by less than five percent.
We propose a possibility of the 125 GeV Higgs being a pseudo-Goldstone boson in supersymmetry with extra vector-like fermions. Higgs mass is obtained from loops of top quark and vector-like fermions from the global symmetry breaking scale f at around TeV. The mu, Bmu/mu \sim f are generated from the dynamics of global symmetry breaking and the Higgs quartic coupling vanishes at f as tan beta \simeq 1. The relation of msoft \sim $4πM_Z$ with f \sim mu \sim m_soft \sim TeV is obtained and large mu does not cause a fine tuning for the electroweak symmetry breaking. The Higgs to di-photon rate can…
The Higgs sector is extended in $R$-symmetric supersymmetry theories by two iso-doublets $R_{d,u}$ which complement the standard iso-doublets $H_{d,u}$. We have analyzed masses and interactions of these novel states and describe their [non-standard] decay modes and their production channels at the LHC and $e^+e^-$ colliders.
Detection of Intermediate Mass Higgs Bosons from Spontaneously Broken R Parity Supersymmetry
在自发破缺的R宇称超对称（RPSUSY）的希格斯部门显示出有趣的功能，需要新的搜索技术。质谱和生产率可能与标准模型和最小超对称模型（MSSM）的预期不同。对于某些参数的选择，占主导地位的希格斯玻色子玻色子衰变模式甚至可以是不可见的，从而导致具有由超弱相互作用的强子携带的大的缺失横向动量的事件。我们研究了反应$pp \ra Z + H + X$，发现在LHC/SSC上，它能在很大的参数空间范围内产生可探测事件。
We investigate the limits on the higgs mass in variations of Split Supersymmetry, where the boundary value of the Higgs quartic coupling at the SUSY breaking scale ($m_s$) is allowed to deviate from its value in the minimal model of Arkani-Hamed and Dimopoulos. We show that it is possible for $λ(m_s)$ to be negative and use vacuum stability to put a lower bound on this coupling, and hence on the mass of the physical higgs. We also use the requirement of perturbativity of all couplings up to the cutoff to determine an upper limit for the higgs mass in models which are further modified by additi…
We explore the LHC phenomenology of an extension of warped higgsless models. The model is supersymmetric in the bulk and on the IR brane as introduced in [arXiv:0805.1379], corresponding to an emergence of a supersymmetric spectrum in the composite sector of the higgsless model. In particular, the lightest neutralino is rendered stable by an R parity and serves as a realistic cold dark matter candidate. The observation of missing energy signals at the LHC from LSP and NLSP production in association with third generation quarks is discussed based on simulations using WHIZARD.
