We propose a simple model in which the baryon asymmetry and dark matter are created via the decays and inverse decays of QCD-triplet scalars, at least one of which must be in the TeV mass range. Singlet fermions produced in these decays constitute the dark matter. The singlets never reach equilibrium, and their coherent production, propagation, and annihilation generates a baryon asymmetry. We find that that the out-of-equilibrium condition and the dark matter density constraint typically require the lightest scalar to be long-lived, giving good prospects for detection or exclusion in current and upcoming colliders. In generalizing the leptogenesis mechanism of Akhmedov, Rubakov and Smirnov, our model expands the phenomenological possibilities for low-scale baryogenesis.
These lectures, presented at TASI 2018, provide a concise introduction to inflation, baryogenesis, and aspects of dark matter not covered by the other lectures. The emphasis for inflation is an intuitive understanding and techniques for constraining inflationary models. For baryogenesis we focus on two examples, leptogenesis and electroweak baryogenesis, with attention to singlet-assisted two-step phase transitions. Concerning dark matter, we review different classes of models distinguished by their mechanisms for obtaining the observed relic density, including thermal freeze-out, asymmetric d…
We study a mechanism through which the cosmic dark matter density can be explained simultaneously with the observed baryon asymmetry of the Universe. At the core of our proposal lie the out-of-equilibrium scattering processes of bath particles which are responsible for the production of feebly-interacting dark matter. The same processes violate $CP$, which further leads to an asymmetry between matter and antimatter being generated in the visible sector. We focus on the possibility that these interactions are described through non-renormalizable operators, which leads to both dark matter and th…
The $ν$MSM -- an extension of the Standard Model by three relatively light singlet Majorana fermions $N_{1,2,3}$ -- allows for the generation of lepton asymmetry which is several orders of magnitude larger than the observed baryon asymmetry of the Universe. The lepton asymmetry is produced in interactions of $N_{2,3}$ (with masses in the GeV region) at temperatures below the sphaleron freeze out $ T \lesssim 130$ GeV and can enhance the cosmological production of dark matter (DM) sterile neutrinos $N_1$ (with the mass of the keV scale) happening at $T \sim 200$ MeV due to active-sterile neutri…
It was recently proposed that weakly interacting massive particles (WIMP) may provide new ways of generating the observed baryon asymmetry in the early universe, as well as addressing the cosmic coincidence between dark matter and baryon abundances. This suggests a new possible connection between weak scale new particle physics and modern cosmology. This review summarizes the general ideas and simple model examples of the two recently proposed WIMP baryogenesis mechanisms: baryogenesis from WIMP dark matter annihilation during thermal freezeout, and baryogenesis from metastable WIMP decay afte…
This is a very short review on different mechanisms for baryogenesis from particle decays or annihilations at low temperature (T < ~ 10 TeV) and their implementation in models that relate the origin of the baryon asymmetry and dark matter.
We explore models in which weakly interacting massive particle (WIMP) dark matter annihilation is directly responsible for baryogenesis, thereby connecting dark matter with baryogenesis. We call this process "WIMPy baryogenesis". The dark matter relic density in these models, as with conventional WIMP models, is obtained with only order one couplings and TeV-scale masses according to the WIMP miracle. Thus, WIMPy baryogenesis models naturally accommodate weak-scale dark matter. Furthermore, an extension of the WIMP miracle simultaneously explains the observed baryon asymmetry and the correct d…
We analyse a simple extension of the SM with just an additional scalar singlet coupled to the Higgs boson. We discuss the possible probes for electroweak baryogenesis in this model including collider searches, gravitational wave and direct dark matter detection signals. We show that a large portion of the model parameter space exists where the observation of gravitational waves would allow detection while the indirect collider searches would not.
We consider the possibility that some primordial fields decay purely into the dark sector creating asymmetric dark matter. This asymmetry is subsequently transmuted into leptons and baryons. Within this paradigm we compute the amount of asymmetric dark matter created from the out of equilibrium decays of the primordial fields with CP violating Yukawa couplings. The dark matter asymmetry is then transferred to the visible sector by the asymmetry transfer equation and generates an excess of $B-L$. Baryogenesis occurs via sphaleron processes which conserve $B-L$ but violate $B+L$. A mechanism for…
We propose a robust, unified framework, in which the similar baryon and dark matter cosmic abundances both arise from the physics of weakly interacting massive particles (WIMPs), with the rough quantitative success of the so-called "WIMP miracle". In particular the baryon asymmetry arises from the decay of a meta-stable WIMP after its thermal freezeout at or below the weak scale. A minimal model and its embedding in R-parity violating (RPV) SUSY are studied as examples. The new mechanism saves RPV SUSY from the potential crisis of washing out primordial baryon asymmetry. Phenomenological impli…
We investigate the scenario that one flat direction creates baryon asymmetry of the unverse, while Q balls from another direction can be the dark matter in the gauge-mediated supersymmetry breaking for high-scale inflation. Isocurvature fluctuations are suppressed by the fact that the Affleck-Dine field stays at around the Planck scale during inflation. We find that the dark matter Q balls can be detected in IceCube-like experiments in the future.
We present a very minimal model for baryogenesis by a dark first-order phase transition. It employs a new dark $SU(2)_{D}$ gauge group with two doublet Higgs bosons, two lepton doublets, and two singlets. The singlets act as a neutrino portal that transfer the generated asymmetry to the Standard Model. The model predicts $ΔN_\text{eff} = 0.09-0.13$ detectable by future experiments as well as possible signals from exotic decays of the Higgs and $Z$ bosons and stochastic gravitational waves.
We propose a new seesaw model in an extra-dimensional setup where only right-handed neutrinos are bulk fields. In the model, localizations of an extra-dimensional wave function and brane Majorana mass of the right-handed neutrinos can be different among each generation of the right-handed neutrinos. The setup can lead to different suppression factor dependences of effective right-handed neutrino masses and neutrino Yukawa couplings for each generation. It is shown that the resultant mass spectra of the right-handed neutrinos and neutrino Yukawa couplings are favored in models of neutrino dark …
We propose a WIMP baryogensis achieved by the annihilation of non-thermally produced WIMPs from decay of heavy particles, which can result in low reheating temerature. Dark matter (DM) can be produced non-thermally during a reheating period created by the decay of long-lived heavy particle, and subsequently re-annihilate to lighter particles even after the thermal freeze-out. The re-annihilation of DM provides the observed baryon asymmetry as well as the correct relic density of DM. We investigate how wahout effects can affect the generation of the baryon asymmetry and study a model suppressin…
We study baryogenesis via a gaugino portal, the supersymmetric counterpart to the widely studied kinetic mixing portal, to a hidden sector. CP and baryon number violating decays of a hidden sector gaugino into the visible sector can produce the observed baryon asymmetry of the Universe. The tiny portal coupling is crucial in producing late out-of-equilibrium decays, after washout processes that can erase the asymmetry have gone out of equilibrium. We study this mechanism within various scenarios, including freeze-in or freeze-out of the hidden gaugino, as well as extended frameworks where the …
We show that vector-like fermions can act as the dark matter candidate in the universe whilst also playing a crucial role in electroweak baryogenesis through contributing to the barrier in the one-loop thermal scalar potential. In order for the new fermions to give rise to a strong first order phase transition, we show that one requires rather large Yukawa couplings in the new sector, which are strongly constrained by electroweak precision tests and perturbativity. Strong couplings between the dark matter candidate and the Higgs boson intuitively lead to small values of the relic density and p…
It was recently suggested that dark matter consists of ~GeV particles that carry baryon number and mix with the neutron. We demonstrate that this could allow for resonant dark matter-neutron oscillations in the early universe, at finite temperature, leading to low-scale baryogenesis starting from a primordial dark matter asymmetry. In this scenario, the asymmetry transfer happens around 30 MeV, just before big bang nucleosynthesis. We illustrate the idea using a model with a dark U(1)' gauge interaction, which has recently been suggested as a way of addressing the neutron lifetime anomaly. The…
Adding an extra singlet scalar $S$ to the Higgs sector can provide a barrier at tree level between a false vacuum with restored electroweak symmetry and the true one. This has been demonstrated to readily give a strong phase transition as required for electroweak baryogenesis. We show that with the addition of a fermionic dark matter particle $χ$ coupling to $S$, a simple UV-complete model can realize successful electroweak baryogenesis. The dark matter gets a CP asymmetry that is transferred to the standard model through a $CP\ portal\ interaction$, which we take to be a coupling of $χ$ to $τ…
We show that "accidental" supersymmetry is a beyond-the-Standard Model framework that naturally accommodates a thermal relic dark matter candidate and successful electroweak baryogenesis, including the needed strongly first-order character of the electroweak phase transition. We study the phenomenology of this setup from the standpoint of both dark matter and baryogenesis. For energies around the electroweak phase transition temperature, the low-energy effective theory is similar to the MSSM with light super-partners of the third-generation quarks and of the Higgs and gauge bosons. We calculat…
We study the impact of recent direct and indirect searches for particle dark matter on supersymmetric models with resonant neutralino- or chargino-driven electroweak baryogenesis (EWB) and heavy sfermions. We outline regions of successful EWB on the planes defined by gaugino and higgsino mass parameters, and calculate the portions of those planes excluded by dark matter search results, and the regions soon to be probed by current and future experiments. We conclude that dark matter searches robustly exclude a wino-like lightest supersymmetric particle in successful EWB regions. Bino-like dark …
We propose a minimal predictive scenario for dark matter and radiative neutrino mass where the relic abundance of dark matter is generated from a hybrid setup comprising of both thermal freeze-out as well as non-thermal freeze-in mechanisms. Considering three copies of fermion triplets and one scalar doublet, odd under an unbroken $\mathbb{Z}_2$ symmetry, to be responsible for radiative origin of neutrino mass, we consider the lightest fermion triplet as a dark matter candidate which remains under-abundant in the sub-TeV regime from usual thermal freeze-out. Late decay of the $\mathbb{Z}_2$-od…
Mechanisms for the generation of the matter-antimatter asymmetry and dark matter strongly depend on the reheating temperature T_R, the maximal temperature reached in the early universe. Forthcoming results from the LHC, low energy experiments, astrophysical observations and the Planck satellite will significantly constrain baryogenesis and the nature of dark matter, and thereby provide valuable information about the very early hot universe. At present, a wide range of reheating temperatures is still consistent with observations. We illustrate possible origins of matter and dark matter with fou…
Particle-antiparticle perturbation superhorizon crossing: baryogenesis, leptogenesis, magnetogenesis and darkogenesis
ICRANet（国际相对论天体物理中心）；Sapienza University of Rome（罗马大学）；INFN, Sezione di Perugia（意大利国家核物理研究所佩鲁贾分部）；ICTP-AP, University of Chinese Academy of Sciences（中国科学院大学理论物理与应用物理研究中心）
We investigate that the two types of the Q balls explain the baryon asymmetry and the dark matter of the universe in the gauge-mediated supersymmetry breaking. The gauge-mediation type Q balls of one flat direction produce baryon asymmetry, while the new type Q balls of another flat direction become the dark matter. We show that the dark matter new type Q balls are free from the neutron star constraint. n=5 gauge mediation type and n=6 new type Q balls are displayed as an example, where the potential is lifted by the superpotential Phi^n. These dark matter Q balls may be detected by future obs…
We study the cosmology and phenomenology of freeze-in baryogenesis via dark-matter oscillations, taking the dark matter to couple to Standard Model leptons. We investigate viable models both with and without a $Z_2$ symmetry under which all new fields are charged. Lepton flavor effects are important for leptogenesis in these models, and we identify scenarios in which the baryon asymmetry is parametrically distinct from and enhanced relative to leptogenesis from sterile neutrino oscillations. The models we study predict the existence of new, electroweak-charged fields, and can be tested by a co…
We investigate a simplified freeze-in dark-matter model in which the dark matter only interacts with the standard-model neutrinos via a light scalar. The extremely small coupling for the freeze-in mechanism is naturally realized in several neutrino-portal scenarios with the secret neutrino interactions. We study possible evolution history of the dark sector: the dark sector would undergo pure freeze-in production if the interactions between the dark-sector particles are negligible, while thermal equilibrium within the dark sector could occur if the reannihilation of the dark matter and the sca…
The discovery of the primordial B-mode polarisation by the BICEP2 experiment indicates inflation with a relatively high energy scale. Taking this indication into account, we propose consistent scenarios to account for the observed baryon and dark matter densities in gravity and gauge mediated supersymmetry breaking models. The baryon asymmetry is explained by the Afflck-Dine mechanism, which requires relatively low reheating temperature to avoid a sizable baryonic isocurvature perturbation. The low reheating temperature then requires non-thermal production of dark matter to account for the cor…
We propose a scenario of brane cosmology in which the Peccei-Quinn field plays the role of the inflaton and solves simultaneously many cosmological and phenomenological issues such as the generation of a heavy Majorana mass for the right-handed neutrinos needed for seesaw mechanism, MSSM $μ$-parameter, the right amount of baryon number asymmetry and dark matter relic density at the present universe, together with an axion solution to the strong CP problem without the domain wall obstacle. Interestingly, the scales of the soft SUSY-breaking mass parameter and that of the breaking of $U(1)_{\rm …
If the Higgs boson H couples to a singlet scalar S via lambda_m |H|^2 S^2, a strong electroweak phase transition can be induced through a large potential barrier that exists already at zero temperature. In this case properties of the phase transition can be computed analytically. We show that electroweak baryogenesis can be achieved using CP violation from a dimension-6 operator that couples S to the top-quark mass, suppressed by a new physics scale that can be well above 1 TeV. Moreover the singlet is a dark matter candidate whose relic density is < 3% of the total dark matter density, but wh…
Explaining baryon asymmetry, dark matter and inflation are important elements of a successful theory that extends beyond the Standard Model of particle physics. In this paper we explore these issues within the Next-to-Minimal Supersymmetric Standard Model (NMSSM), by studying the conditions for a strongly first order electroweak phase transition, the abundance of the lightest supersymmetric particle (LSP), and inflation driven by a gauge invariant flat direction of MSSM made up of right handed squarks. We present the regions of parameter space which can yield successful predictions for cosmic …
We revisit dark-matter production through freeze-in and freeze-out by solving the Boltzmann equations at the level of the phase-space distribution $f(p,t)$. Using the $2\to2$ annihilation and the $1\to2$ decay processes for illustration, we compare the resulting dark-matter relic abundance with that from the number-density approach. In the transition regime between freeze-in and freeze-out, we find the difference can be quite significant, or even by orders of magnitude if the annihilation of dark-matter particles or the decaying mediator is neglected. The freeze-in production in the $2\to2$ an…
It is shown that the mixing of lepton doublets of the Standard Model can yield sizeable contributions to the lepton asymmetry, that is generated through the decays of right-handed neutrinos at finite temperature in the early Universe. When calculating the flavour-mixing correlations, we account for the effects of Yukawa as well as of gauge interactions. We compare the freeze-out asymmetry from lepton-doublet mixing to the standard contributions from the mixing and direct decays of right-handed neutrinos. The asymmetry from lepton mixing is considerably large when the mass ratio between the rig…
The universe has evolved through several phases as its various constituents dominated its energy content. Candidate dark matter particles may have undergone freeze-out during any such phase. While the standard freeze-out scenarios have been explored during the radiation-dominated era, and more recently during scalar field decay, this work extends the study of dark matter freeze-out to a potential early period during which the universe is matter-dominated and its evolution adiabatic. Decoupling during an adiabatic matter dominated era changes the freeze-out dynamics, since the Hubble rate is pa…
DarkSUSY is a versatile tool for precision calculations of a large variety of dark matter-related signals, ranging from predictions for the dark matter relic density to dark matter self-interactions and rates relevant for direct and indirect detection experiments. In all of these areas significant new code additions have been made in recent years, since the release of DarkSUSY 6 in 2018, which we summarize in this overview. In particular, DarkSUSY now allows users to compute the relic density for feebly interacting massive particles via the freeze-in mechanism, but also offers new routines for…
The early universe could feature multiple reheating events, leading to jumps in the visible sector entropy density that dilute both particle asymmetries and the number density of frozen-out states. In fact, late time entropy jumps are usually required in models of Affleck-Dine baryogenesis, which typically produces an initial particle-antiparticle asymmetry that is much too large. An important consequence of late time dilution, is that a smaller dark matter annihilation cross section is needed to obtain the observed dark matter relic density. For cosmologies with high scale baryogenesis, follo…
We propose a new mechanism to simultaneously explain the observed dark matter abundance and the baryon asymmetry of the Universe. The mechanism is based on the Filtered Dark Matter scenario, where dark matter particles acquire a large mass during a first-order phase transition. This implies that only a small fraction of them are energetic enough to enter the advancing true vacuum bubbles and survive until today, while the rest are reflected and annihilate away quickly. We supplement this scenario with a CP-violating interaction, which creates a chiral asymmetry in the population of dark matter…
The cosmological phase transition with Q-balls production mechanism can explain the baryogenesis and dark matter simultaneously, where constraints on dark matter masses and reverse dilution are significantly relaxed. We study how to probe this scenario by collider signals at QCD next-to-leading order and gravitational wave signals.
We introduce and study a model designed to simultaneously shed light on the mysteries connected with Baryogenesis, Dark Matter and Dark Energy. The model describes a self-interacting complex axion field whose imaginary part, a pseudo-scalar axion, couples to the instanton density of gauge fields including the hypermagnetic field. This coupling may give rise to baryogenesis in the early universe. After tracing out the gauge and matter degrees of freedom, a non-trivial effective potential for the angular component of the axion field is obtained. It is proposed that oscillations of this component…
It is well known that R-symmetric models dramatically alleviate the SUSY flavor and CP problems. We study particular modifications of existing R-symmetric models which share the solution to the above problems, and have interesting consequences for electroweak baryogenesis and the Dark Matter (DM) content of the universe. In particular, we find that it is naturally possible to have a strongly first-order electroweak phase transition while simultaneously relaxing the tension with EDM experiments. The R-symmetry (and its small breaking) implies that the gauginos (and the neutralino LSP) are pseud…
We propose a novel mechanism to generate a suitable baryon asymmetry from dark (hidden) sector. This is a Baryogenesis through a reverse pathway of the "asymmetric dark matter" scenario. In the mechanism, the asymmetry of dark matter is generated at first, and it is partially transferred into a baryon asymmetry in the standard model sector. This mechanism enables us not only to realize the generation of the baryon asymmetry but also to account for the correct amount of dark matter density in the present universe within a simple framework.
The model of radiative neutrino mass with dark matter proposed by one of us is extended to include a real singlet scalar field. There are then two important new consequences. One is the realistic possibility of having the lightest neutral singlet fermion (instead of the lightest neutral component of the dark scalar doublet) as the dark matter of the Universe. The other is a modification of the effective Higgs potential of the Standard Model, consistent with electroweak baryogenesis.
We consider axino dark matter in large R-parity violation (RPV). In moduli-dominated universe, axino is produced thermally or non-thermally via saxion decay, then late-decaying moduli dilute axino density, which results in the right abundance to explain the present dark matter. At the same time baryon asymmetry is generated due to moduli-induced baryogenesis via the large RPV. Axino is cosmologically stable in spite of the large RPV since its decay rate is suppressed by the axion decay constant, heavy squark mass or kinematics.
We study a scenario in which the baryon asymmetry is created through Hawking radiation from primordial black holes via a dynamically-generated chemical potential. This mechanism can also be used to generate the observed dark matter abundance, regardless of whether or not the black holes fully evaporate. In the case that evaporation ceases, the observed dark matter abundance is generically comprised of both relic black holes and an asymmetric dark matter component. We show that this two-component dark matter scenario can simultaneously account for the observed baryon asymmetry and the cosmologi…
If the dark matter is produced in the early universe prior to Big Bang nucleosynthesis, a modified cosmological history can drastically affect the abundance of relic dark matter particles. Here, we assume that an additional species to radiation dominates at early times, causing the expansion rate at a given temperature to be larger than in the standard radiation-dominated case. We demonstrate that, if this is the case, dark matter production via freeze-in (a scenario when dark matter interacts very weakly, and is dumped in the early universe out of equilibrium by decay or scattering processes …
We study the conditions for successful Affleck-Dine baryogenesis and the origin of gravitino dark matter in GMSB models. AD baryogenesis in GMSB models is ruled out by neutron star stability unless Q-balls are unstable and decay before nucleosynthesis. Unstable Q-balls can form if the messenger mass scale is larger than the flat-direction field Phi when the condensate fragments. We provide an example based on AD baryogenesis along a d = 6 flat direction for the case where m_{3/2} \approx 2 GeV, as predicted by gravitino dark matter from Q-ball decay. Using a phenomenological GMSB potential whi…
