We perform a study on the predictions of electric-dipole moments (EDMs) of neutron, Mercury (Hg), Thallium (Tl), deuteron, and Radium (Ra) in the framework of next-to-minimal supersymmetric standard model (NMSSM) with CP-violating parameters in the superpotential and soft-supersymmetry-breaking sector. We confine to the case in which only the physical tree-level CP phase $(ϕ'_λ- ϕ'_κ)$, associated with the couplings of the singlet terms in the superpotential and with the vacuum-expectation-values (VEVs), takes on a nonzero value. We found that the one-loop contributions from neutralinos are mostly small while the two-loop Higgs-mediated contributions of the Barr-Zee (BZ) type diagrams dominate. We emphasize a scenario motivated by electroweak baryogenesis.
It is conventional wisdom that successful electroweak baryogenesis in the Minimal Supersymmetric extension of the Standard Model (MSSM) is in tension with the non-observation of electric dipole moments (EDMs), since the level of CP-violation responsible for electroweak baryogenesis is believed to generate unavoidably large EDMs. We show that CP-violation in the bino-Higgsino sector of the MSSM can account for successful electroweak baryogenesis without inducing large EDMs. This observation weakens the correlation between electroweak baryogenesis and EDMs, and makes the bino-driven electroweak …
We study the prospect of probing electroweak baryogenesis driven by an extra bottom Yukawa coupling $ρ_{bb}$ in a general two Higgs doublet model via electric dipole moment (EDM) measurements and at the collider experiments. The parameter space receives meaningful constraints from 125 GeV Higgs $h$ boson signal strength measurements as well as several heavy Higgs boson searches at the Large Hadron Collider (LHC). In addition, we show that the asymmetry of the CP asymmetry of inclusive $B\to X_s γ$ decay would provide complementary probe. A discovery is possible at the LHC via $bg\to bA \to b Z…
Flavor-changing terms with CP-violating phases in the quark sector may contribute to the hadronic electric dipole moments (EDMs). However, within the Standard Model (SM), the source of CP violation comes from the unique CKM phase, and it turns out that the EDMs are strongly suppressed. This implies that the EDMs are very sensitive to non-minimal flavor violation structures of theories beyond the SM. In this paper, we discuss the quark EDMs and CEDMs (chromoelectric dipole moments) in the MSSM with general flavor-changing terms in the squark mass matrices. In particular, the charged-Higgs media…
An analysis of the electric dipole moment (EDM) of the neutron and of the leptons in the minimal supersymmetric standard model (MSSM) with the most general allowed set of CP violating phases without generational mixing is given. The analysis includes the contributions from the gluino, the chargino and the neutralino exchanges to the electric dipole operator, the chromoelectic dipole operator, and the CP violating purely gluonic dimension six operator. It is found that the EDMs depend only on certain combination of the CP phases. The independent set of such phases is classified. The analysis of…
The searching for the electric dipole moments (EDMs) of neutron ($d_n$), $b$ quark ($d_b$) and $c$ quark ($d_c$) gives strict upper bounds on these quantities. And recently, new upper bounds on $d_b$, $d_c$ are obtained by the strict limit on $d_n$. The models of new physics (NP) with additional CP-violating (CPV) sources are constrained strictly by these EDMs. In this work, we focus on the CPV effects on these EDMs in the minimal supersymmetric extension (MSSM) of the SM with local $B-L$ gauge symmetry (B-LSSM). The contributions from one-loop and some two-loop diagrams to the quark EDM are g…
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…
We explore a new possibility of electroweak baryogenesis in the next-to-minimal supersymmetric standard model. In this model, a strong first-order electroweak phase transition can be achieved due to the additional singlet Higgs field. The new impact of its superpartner (singlino) on the baryon asymmetry is investigated by employing the closed-time-path formalism. We find that the CP violating source term fueled by the singlino could be large enough to generate the observed baryon asymmetry of the Universe without any conflicts with the current constraints from the non-observation of the Thalli…
Baryon asymmetry of the universe is generated in the supersymmetric standard model (SSM) through the charge transport mechanism mediated by top squarks. Necessary CP violation originates from a complex phase contained in mass-squared matrices of squarks and sleptons. This complex phase also gives contributions to the electric dipole moments (EDMs) of the neutron and the electron. The amount of induced baryon asymmetry is consistent with its observed value within reasonable ranges of SSM parameters. The EDMs are predicted to be slightly smaller than their experimental upper limits.
We investigate the implications of the Higgs rate measurements from Run 1 of the LHC for the mass of the light scalar top partner (stop) in the Minimal Supersymmetric Standard Model (MSSM). We focus on light stop masses, and we decouple the second, heavy stop and the gluino to the multi-TeV range in order to obtain a Higgs mass of around 125 GeV. We derive lower mass limits for the light stop within various scenarios, taking into account the effects of a possibly light scalar tau partner (stau) or chargino on the Higgs rates, of additional Higgs decays to undetectable new physics, as well as o…
We show that in the MSSM without R-parity symmetry there are no new contributions to electron and neutron electric dipole moments (EDMs) at 1-loop induced by the R-parity violating Yukawa couplings. Non-zero EDMs for the electron and neutron first arise at the 2-loop level. As an example we estimate the contribution of a two-loop graph which induces electron EDMs. On the other hand, we show that the (Majorana) neutrino electric and magnetic transition moments are non-zero even at the 1-loop level. Constraints on the R-parity violating couplings are derived from the existing bounds on the neutr…
In the context of the MSSM the Light Stop Scenario (LSS) is the only region of parameter space that allows for successful Electroweak Baryogenesis (EWBG). This possibility is very phenomenologically attractive, since it allows for the direct production of light stops and could be tested at the LHC. The ATLAS and CMS experiments have recently supplied tantalizing hints for a Higgs boson with a mass of ~ 125 GeV. This Higgs mass severely restricts the parameter space of the LSS, and we discuss the specific predictions made for EWBG in the MSSM. Combining data from all the available ATLAS and CMS…
We study the simplest generic extension of the Standard Model which allows for conventional electroweak baryogenesis, through the addition of dimension six operators in the Higgs sector. At least one such operator is required to be CP-odd, and we study the constraints on such a minimal setup, and related scenarios with minimal flavor violation, from the null results of searches for electric dipole moments (EDMs), utilizing the full set of two-loop contributions to the EDMs. The results indicate that the current bounds are stringent, particularly that of the recently updated neutron EDM, but fa…
We study electroweak baryogenesis and electric dipole moments in the presence of the two leading-order, non-renormalizable operators in the Higgs sector of the MSSM. Significant qualitative and quantitative differences from MSSM baryogenesis arise due to the presence of new CP-violating phases and to the relaxation of constraints on the supersymmetric spectrum (in particular, both stops can be light). We find: (1) spontaneous baryogenesis, driven by a change in the phase of the Higgs vevs across the bubble wall, becomes possible; (2) the top and stop CP-violating sources can become effective; …
We compare electroweak baryogenesis in the MSSM, nMSSM and NMSSM. We comment on the different sources of CP violation, the phase transition and constraints from EDM measurements.
We revisit the electroweak baryogenesis within the context of the minimal supersymmetric standard model (MSSM), studying its potential collider signatures. We find that this mechanism of baryogenesis does not give a new CP violating signal at the $B$-factories. The first circumstantial evidence may come from enhanced $B_s$ or $B_d$ mixing. If a light right-handed scalar top and Higgs are found as required, a linear collider represents the best possibility for confirming the scenario.
We study electric dipole moment bounds on CP-violating phases in the MSSM with special emphasis on the cancelation scenario. We find that in the range favored by electroweak baryogenesis ({\it i.e.,} $|μ|\simeq M_1$ or $|μ|\simeq M_2$), $\sin [θ_μ+θ_{M_1}]$ can be as large as ${\cal O}(1)$, even for slepton masses below 500 GeV. Such large values of the phases promise a successful electroweak baryogenesis. We also discuss the possibility of large CP-odd effects at a linear collider.
We review the baryogenesis scenario in the MSSM at the perturbative level and, in particular, the impact of two-loop corrections on the strength of the phase transition and the amount of generated baryon asymmetry. We confirm the baryogenesis window, where m_H is less than 115GeV, for m_Q less than a few GeV, and the right-handed stop mass is constrained in the region between 100GeV and the top mass. This scenario will be tested at LEP and Tevatron colliders.
We study general aspects of the CP-violating effects on the baryon asymmetry of the Universe (BAU) and electric dipole moments (EDMs) in models extended by an extra Higgs doublet and a singlet, together with electroweak-interacting fermions. In particular, the emphasis is on the structure of the CP-violating interactions and dependences of the BAU and EDMs on masses of the relevant particles. In a concrete mode, we investigate a relationship between the BAU and the electron EDM for a typical parameter set. As long as the BAU-related CP violation predominantly exists, the electron EDM has a str…
Taking the MSSM as an effective low-energy theory, with a cut-off scale of a few TeV, can make significant modifications to the predictions concerning the Higgs and stop sectors. We investigate the consequences of such a scenario for electroweak baryogenesis. We find that the window for MSSM baryogenesis is extended and, most important, can be made significantly more natural. Specifically, it is possible to have one stop lighter than the top and the other significantly lighter than TeV simultaneously with the Higgs mass above the LEP bound. In addition, various aspects concerning CP violation …
We show that, for all values of $Tan β$ and the light right-handed stop mass for which the electroweak phase transition is strong enough to avoid washout following electroweak baryogenesis, the electroweak vacuum is stable over the lifetime of the observed Universe. Cosmological stability of the electroweak vacuum is violated only if the light right-handed stop is lighter than 100-115GeV.
We have analyzed baryogenesis in the MSSM for the light stop scenario, where the phase transition is strong enough first order. We have found that enough baryon asymmetry can be generated provided that the phase of $μ$ be $\simgt$ 0.01. Constraints from the electric dipole moment of the neutron enforce the first and second generation squarks to have masses O(few) TeV
The minimal supersymmetric extension of the standard model (MSSM) is extended to the $U(1)_X$SSM, whose local gauge group is $SU(3)_C \times SU(2)_L \times U(1)_Y \times U(1)_X$. To obtain the $U(1)_X$SSM, we add the new superfields to the MSSM, namely: three Higgs singlets $\hatη,~\hat{\barη},~\hat{S}$ and right-handed neutrinos $\hatν_i$. The CP violating effects are considered to study the lepton electric dipole moment(EDM) in $U(1)_X$SSM. The CP violating phases in $U(1)_X$SSM are more than those in the standard model(SM). In this model, some new parameters $(θ_S, θ_{BB^{\prime}}, θ_{BL})$…
We explore the implications of electroweak baryogenesis for future searches for permanent electric dipole moments in the context of the minimal supersymmetric extension of the Standard Model (MSSM). From a cosmological standpoint, we point out that regions of parameter space that over-produce relic lightest supersymmetric particles can be salvaged only by assuming a dilution of the particle relic density that makes it compatible with the dark matter density: this dilution must occur after dark matter freeze-out, which ordinarily takes place after electroweak baryogenesis, implying the same deg…
We present an analysis of the thermalization rate of Higgsinos and winos based on the imaginary part of the two-point Green function in the {\it unbroken} phase of the MSSM. We use improved propagators including resummation of hard thermal loops and the thermalization rate is computed at the one-loop level in the high temperature approximation. We find that the damping is typically dominated by scattering with gauge bosons, resulting in a damping rate of about $γ_{\Ht}\simeq 0.025T$, $γ_{\Wt}\simeq 0.065T$. The contribution from scattering with scalars is relatively small. Implications for bar…
Updated Constraints from Electric Dipole Moments in the MSSM with R-Parity Violation
Santa Cruz Institute for Particle Physics and Department of Physics, University of California Santa Cruz（加州大学圣克鲁兹分校物理系及粒子物理研究所）；Department of Physics and McDonnell Center for the Space Sciences, Washington University（华盛顿大学物理系及麦克唐纳空间科学中心）；PRISMA + Cluster of Excellence & Mainz Institute for Theoretical Physics, Johannes Gutenberg-Universität Mainz（约翰内斯·古腾堡美因茨大学美因茨理论物理研究所及PRISMA+卓越集群）；Physics Department, Brookhaven National Laboratory（布鲁克海文国家实验室物理系）；Department of Physics, Center for Field Theory and Particle Physics, Fudan University（复旦大学物理系及场论与粒子物理中心）
Non-minimal supersymmetric models that predict a tree-level Higgs mass above the Minimal Supersymmetric Standard Model (MSSM) bound are well motivated by naturalness considerations. Indirect constraints on the stop sector parameters of such models are significantly relaxed compared to the MSSM; in particular, both stops can have weak-scale masses. We revisit the stop-catalyzed electroweak baryogenesis (EWB) scenario in this context. We find that the LHC measurements of the Higgs boson production and decay rates already rule out the possibility of stop-catalyzed EWB. We also introduce a gauge-i…
Introducing heavy particles with strong couplings to the Higgs field can strengthen electroweak phase transition, through the entropy release mechanism from both bosons and fermions. We analyze the possibility of electroweak baryogenesis in the MSSM with new vector-like superfields. The new vector-like particles belong to the representation 5+5bar+10+10bar of SU(5). By analyzing in detail the effective potential at finite temperature, we show that a strongly first order electroweak phase transition in this model is ruled out by a combination of 125 GeV Higgs requirement, the bound for exotic q…
We show that EDMs obey a simple approximate scaling under the transformation $m_0\to λm_0,m_{1/2}\to λm_{1/2}$ in the large $μ$ region when $μ$ itself obeys the same scaling, ie., $μ\to λμ$. In the scaling region the knowledge of a single point in the MSSM parameter space where the cancellation in the EDMs occur allows one to generate a trajectory in the $m_0-m_{1/2}$ plane where the cancellation mechanism holds and the EDMs are small. We illustrate these results for MSSM with radiative electro-weak symmetry breaking constraints. We also discuss a class of D brane models based on Type IIB supe…
Electroweak baryogenesis (EWBG) in the MSSM can account for the cosmological baryon asymmetry, but only within a restricted region of the parameter space. In particular, MSSM EWBG requires a mostly right-handed stop that is lighter than the top quark and a standard model-like light Higgs boson. In the present work we investigate the effects of the light stop on Higgs boson production and decay. Relative to the standard model Higgs boson, we find a large enhancement of the Higgs production rate through gluon fusion and a suppression of the Higgs branching fraction into photon pairs. These modif…
A commonly accepted mechanism of generating baryon asymmetry in the minimal supersymmetric standard model (MSSM) depends on the CP violating relative phase between the gaugino mass and the Higgsino mu term. The direct constraint on this phase comes from the limit of electric dipole moments (EDM) of various light fermions. To avoid such a constraint, a scheme which assumes the first two generation sfermions are very heavy is usually evoked to suppress the one-loop EDM contributions. We point out that under such a scheme the most severe constraint may come from a new contribution to the electric…
Electroweak baryogenesis depends on the profile of the bubble wall created in the first-order phase transition. It is pointed out that CP violation in the Higgs sector of the MSSM could become large enough to explain the baryon asymmetry. We confirm this by solving the equations of motion for the Higgs fields with the effective potential at the transition temperature. That is, we present an example such that the transitional CP violation is realized and show the possibility that the baryon asymmetry of the universe may be produced, if marginally, by the $τ$ lepton interacting with the wall, wh…
We present a detailed study of the Thallium, neutron, Mercury and deuteron electric dipole moments (EDMs) in the CP-violating Minimal Supersymmetric extension of the Standard Model (MSSM). We take into account the complete set of one-loop graphs, the dominant Higgs-mediated two-loop diagrams, the complete CP-odd dimension-six Weinberg operator and the Higgs-mediated four-fermion operators. We improve upon earlier calculations by including the resummation effects due to CP-violating Higgs-boson mixing and to threshold corrections to the Yukawa couplings of all up- and down-type quarks and charg…
We analyze the constraints placed on individual, flavor diagonal CP-violating phases in the minimal supersymmetric extension of the Standard Model (MSSM) by current experimental bounds on the electric dipole moments (EDMs) of the neutron, Thallium, and Mercury atoms. We identify the four CP-violating phases that are individually highly constrained by current EDM bounds, and we explore how these phases and correlations among them are constrained by current EDM limits. We also analyze the prospective implications of the next generation of EDM experiments. We point out that all other CP-violating…
Next-to-MSSM is a viable model which is equipped with two features suited for electroweak baryogensis (EWBG): first-order phase transition not restricted by the Higgs spectrum and tree-level CP violation in the Higgs sector free from the nEDM constraints. We study the model when the expectation value of the singlet scalar is of the weak scale. Then the vacuum stability condition puts a novel upper bound on the charged Higgs mass. We determined allowed parameter region by requiring that the each Higgs boson is heavier than 114GeV or its coupling to Z boson is smaller than 0.1.
In the minimal supersymmetric standard model (MSSM), a strongly first-order electroweak phase transition (EWPT) is only possible in a confined parameter region where one of the scalar top quarks is lighter than the top quark and the other one is as heavy as the SUSY breaking scale. If the MSSM is enlarged to accommodate vector-like quarks and their superpartners, we find that the strongly first-order EWPT is possible without requiring light scalar top quark at the one-loop level, in the limit where the lightest scalar Higgs boson of the MSSM behaves like the Higgs boson of the standard model a…
The Minimal Supersymmetric Standard Model can possess several CP-violating phases beyond the conventional Cabibo-Kobayashi-Maskawa phase. We calculate the contribution of these phases to T-violating nuclear forces. These forces induce a Schiff moment in the $^{199}$Hg nucleus, which is strongly limited by experiments aimed at the detection of the electric dipole moment of the mercury atom. The result for $d_{Hg}$ is found to be very sensitive to the CP-violating phases of the MSSM and the calculation carries far fewer QCD uncertainties than the corresponding calculation of the neutron EDM. In …
In the context of the supersymmetrized seesaw mechanism embedded in the Minimal Supersymmetric Standard Model (MSSM), complex neutrino Yukawa couplings can induce Electric Dipole Moments (EDMs) for the charged leptons, providing an additional route to seesaw parameters. However, the complex neutrino Yukawa matrix is not the only possible source of CP violation. Even in the framework of Constrained MSSM (CMSSM), there are additional sources, usually attributed to the phases of the trilinear soft supersymmetry breaking couplings and the mu-term, which contribute not only to the electron EDM but …
We perform a comprehensive study of the dominant two- and higher-loop contributions to the $^{205}$Tl, neutron and muon electric dipole moments induced by Higgs bosons, third-generation quarks and squarks, charginos and gluinos in the Minimal Supersymmetric Standard Model (MSSM). We find that strong correlations exist among the contributing CP-violating operators, for large stop, gluino and chargino phases, and for a wide range of values of $\tanβ$ and charged Higgs-boson masses, giving rise to large suppressions of the $^{205}$Tl and neutron electric dipole moments below their present experim…
Thermal two-loop QCD corrections associated with light stops have a dramatic effect on the strength of the MSSM electroweak phase transition, making it more strongly first order as required for the viability of electroweak baryogenesis. We perform a perturbative analysis of the transition strength in this model, including these important contributions, extending previous work to arbitrary values of the pseudoscalar Higgs boson mass, m_A. We find a strong enough transition in a region with 2< tan beta < 4 and m_A > 120 GeV, a light Higgs boson with nearly standard couplings, and mass below 85 G…
We show that Q-balls naturally exist in the Minimal Supersymmetric Standard Model (MSSM) with soft SUSY breaking terms of the minimal N=1 SUGRA type. These are associated with the F- and D-flat directions of the scalar potential once radiative corrections are taken into account. We consider two distinct cases, corresponding to the "H_u L" (slepton) direction with L-balls and the "udd" and "uude" (squark) directions with B-balls. The L-ball always has a small charge, typically of the order of 1000, whilst the B-ball can have an arbitrarily large charge, which, when created cosmologically by the…
Higgs Mass and CP violating Phases Implications on the SUSY Breaking Scale in MSSM
Center of Fundamental Physics CFP, Zewail City of Science and Technology（扎威尔科学与技术城基础物理中心）；Department of Physics, Faculty of Science, University of Alexandria（亚历山大大学理学院物理系）
We construct an effective three dimensional theory for the MSSM at high temperatures in the limit of large-$m_{A}$. We analyse the two-loop effective potential of the 3D theory for the case of a light right handed stop to determine the precise region in the $m_{h}$-$m_{\tilde{t}_{R}}$ plane for which the sphaleron constraint for preservation of the baryon asymmetry is satisfied. We also compare with results previously obtained usind 3D and 4D calculations of the effective potential. A two-stage phase transition still persists for a small range of values of $m_{\tilde{t}_{R}}$. The allowed regi…
We investigate electric dipole moments (EDMs) in a CP-violating minimal supersymmetric standard model with the Bino-like neutralino dark matter (DM) annihilating through the heavy Higgs funnel. Motivated by the current experimental results, in particular, the measured mass of the standard model-like Higgs boson, we consider a mass spectrum with stop masses of about 10 TeV. For the other sfermions, we consider masses of about 100 TeV. We show that CP-violating phases of the order of ten degrees in gaugino and Higgsino mass parameters are consistent with the current bound by EDMs of the electron…
We make use of the formalism developed in Ref. [1], and calculate the chargino mediated baryogenesis in the Minimal Supersymmetric Standard Model. The formalism makes use of a gradient expansion of the Kadanoff-Baym equations for mixing fermions. For illustrative purposes, we first discuss the semiclassical transport equations for mixing bosons in a space-time dependent Higgs background. To calculate the baryon asymmetry, we solve a standard set of diffusion equations, according to which the chargino asymmetry is transported to the top sector, where it biases sphaleron transitions. At the end …
One of the most experimentally testable explanations for the origin of the baryon asymmetry of the universe is that it was created during the electroweak phase transition, in the minimal supersymmetric standard model. Previous efforts have focused on the current for the difference of the two Higgsino fields, $H_1-H_2$, as the source of biasing sphalerons to create the baryon asymmetry. We point out that the current for the orthogonal linear combination, $H_1+H_2$, is larger by several orders of magnitude. Although this increases the efficiency of electroweak baryogenesis, we nevertheless find …
We discuss the generation of the baryon asymmetry by a strong first order electroweak phase transition in the early universe, particularly in the context of the MSSM. This requires a thorough numerical treatment of the bubble wall profile in the case of two Higgs fields. CP violating complex particle masses varying with the Higgs field in the wall are essential. Since in the MSSM there is no indication of spontaneous CP violation around the critical temperature (contrary to the NMSSM) we have to rely on standard explicit CP violation. Using the WKB approximation for particles in the plasma we …
We study the implications for electroweak baryogenesis (EWB) within the minimal supersymmetric Standard Model (MSSM) of present and future searches for the permanent electric dipole moment (EDM) of the electron, for neutralino dark matter, and for supersymmetric particles at high energy colliders. We show that there exist regions of the MSSM parameter space that are consistent with both present two-loop EDM limits and the relic density and that allow for successful EWB through resonant chargino and neutralino processes at the electroweak phase transition. We also show that under certain condit…
Electroweak baryogenesis provides an attractive explanation of the origin of the matter-antimatter asymmetry that relies on physics at the weak scale and thus it is testable at present and near future high-energy physics experiments. Although this scenario may not be realized within the Standard Model, it can be accommodated within the MSSM provided there are new CP-violating phases and the lightest stop mass is smaller than the top-quark mass. In this work we provide an evaluation of the values of the stop (m_{\tilde t}) and Higgs (m_H) masses consistent with the requirements of electroweak b…
The Standard Model (SM) predictions for the hadronic electric dipole moments (EDMs) are well far from the present experimental resolutions, thus, the EDMs represent very clean probes of New Physics (NP) effects. Especially, within an MSSM framework with flavor-changing (but not necessarily CP violating) soft terms, large and potentially visible effects to the EDMs are typically expected. In this Letter we point out that, beyond-leading-order (BLO) effects, so far neglected in the literature, dominate over the leading-order (LO) effects in large regions of the parameter space, hence, their incl…
We re-examine questions concerning the contribution of the three-gluon Weinberg operator to the electric dipole moment of the neutron, and provide several QCD sum rule-based arguments that the result is smaller than - but nevertheless consistent with - estimates which invoke naive dimensional analysis. We also point out a regime of the MSSM parameter space with light gluinos for which this operator provides the dominant contribution to the neutron electric dipole moment due to enhancement via the dimension five color electric dipole moment of the gluino.
We study the naturalness of electroweak symmetry breaking and baryogenesis in the next-to-minimal supersymmetric standard model (NMSSM). Our study is motivated by the recent LEP bounds on the Higgs boson mass which severely constrains the low \tanβregion of the minimal supersymmetric standard model (MSSM). We show that the low \tan βregion of the NMSSM is clearly favoured over the MSSM with regard to the physical Higgs boson mass, fine-tuning, and electroweak baryogenesis.
Electroweak baryogenesis is an attractive scenario for the generation of the baryon asymmetry of the universe as its realization depends on the presence at the weak scale of new particles which may be searched for at high energy colliders. In the MSSM it may only be realized in the presence of light stops, and with moderate or small mixing between the left- and right-handed components. Consistency with the observed Higgs mass around 125 GeV demands the heavier stop mass to be much larger than the weak scale. Moreover the lighter stop leads to an increase of the gluon-gluon fusion Higgs product…
Modular cosmology is plagued by overproduction of unwanted relics, gravitinos and especially moduli, at relatively low energy scales. Thermal inflation provides a compelling solution to this moduli problem, but invalidates most baryogenesis scenarios. We propose a simple model in which the MSSM plus neutrino mass term $(LH_u)^2$ is supplemented by a minimal flaton sector to drive the thermal inflation, and make two crucial assumptions: the flaton vacuum expectation value generates the $μ$-term of the MSSM and $m_L^2 + m_{H_u}^2 < 0$. The second assumption is particularly interesting in that it…
Recently, it has been found that the tree-level CP invariance of the Higgs potential in the MSSM can be sizeably broken by loop effects due to soft-CP-violating trilinear interactions involving third generation scalar quarks. These soft-CP-violating couplings may be constrained by considering new two-loop contributions to the electron and neutron EDMs. The phenomenological consequences of such a minimal supersymmetric scenario of explicit CP violation at present and future colliders are briefly discussed.
In a variety of supersymmetric extensions of the Standard Model, the scalar partners of the quarks and leptons are predicted to be very heavy and beyond the reach of next-generation colliders. For instance, the realization of electroweak baryogenesis in supersymmetry requires new sources of CP-violation, which can only be naturally accommodated with electric dipole moment constraints if the first and second generation scalar fermions are beyond the TeV scale. Also in focus-point supersymmetry and split supersymmetry the scalar fermions are very heavy. In this work, the phenomenology of scenari…
Affleck-Dine (AD) baryogenesis along a d=6 flat direction in gauge-mediated supersymmetry-breaking (GMSB) models can produce unstable Q-balls which naturally have field strength similar to the messenger scale. In this case a new kind of Q-ball is formed, intermediate between gravity-mediated and gauge-mediated type. We study in detail these new Q-ball solutions, showing how their properties interpolate between standard gravity-mediated and gauge-mediated Q-balls as the AD field becomes larger than the messenger scale. It is shown that E/Q for the Q-balls can be greater than the nucleon mass bu…
In this work, we classify all the effective $U(1)$ symmetries and their associated Noether charges in the Standard Model (SM) and its minimal supersymmetric extension (MSSM) from the highest scale after inflation down to the weak scale. We then demonstrate that the discovery of the violation of baryon minus lepton number ($B-L$) which pinpoints to its violation in primordial Universe at any cosmic temperature above $30$ TeV will open up a new window of baryogenesis in these effective charges above this scale. While the fast SM baryon number violation in the early Universe could be the first pi…
