We investigate the viability of electroweak baryogenesis in a model with a first order electrowea... more We investigate the viability of electroweak baryogenesis in a model with a first order electroweak phase transition induced by the addition of two gauge singlet scalars. A vector-like lepton doublet is introduced in order to provide CP violating interactions with the singlets and Standard Model leptons, and the asymmetry generation dynamics are examined using the vacuum expectation value insertion approximation. We find that such a model is readily capable of generating sufficient baryon asymmetry while satisfying electron electric dipole moment and collider phenomenology constraints.
We revisit the detection of luminous dark matter in direct detection experiments. In this scenari... more We revisit the detection of luminous dark matter in direct detection experiments. In this scenario, dark matter scatters endothermically to produce an excited state, which decays to produce a photon. We explore ways in which the electron recoil signal from the decay photon can be differentiated from other potential electron recoil signals with a narrow spectral shape. We find that larger volume/exposure xenon detectors will be unable to differentiate the signal origin without significant improvements in detector energy resolution of around an order of magnitude. We also explore what can be learned about a generic luminous dark matter signal with a higher resolution detector. Motivated by the advancements in energy resolution by solid-state detectors, we find that sub-eV resolution enables the discovery of LDM in the presence of background levels that would otherwise make observation impossible. We also find that sub-eV resolution can be used to determine the shape of the luminous dark matter decay spectrum and thus constrain the dark matter mass and velocity distribution.
We analyze the implications of neutrino masses for the magnitude of neutrino magnetic moments. By... more We analyze the implications of neutrino masses for the magnitude of neutrino magnetic moments. By considering electroweak radiative corrections to the neutrino mass, we derive modelindependent naturalness upper bounds on neutrino magnetic moments, generated by physics above the electroweak scale. For Majorana neutrinos, these bounds are weaker than present experimental limits if \iy if generated by new physics at ~ 1 TeV, and surpass current experimental sensitivity only for new physics scales > 10-100 TeV. The discovery of a neutrino magnetic moment near present limits would thus signify that neutrinos are Majorana particles.
We consider the consequences for the relic neutrino abundance if extra neutrino interactions are ... more We consider the consequences for the relic neutrino abundance if extra neutrino interactions are allowed, e.g., the coupling of neutrinos to a light (compared to mν) boson. For a wide range of couplings not excluded by other considerations, the relic neutrinos would annihilate to bosons at late times, and thus make a negligible contribution to the matter density today. This mechanism evades the neutrino mass limits arising from large scale structure.
We derive model-independent, "naturalness" upper bounds on the magnetic moments µν of Dirac neutr... more We derive model-independent, "naturalness" upper bounds on the magnetic moments µν of Dirac neutrinos generated by physics above the scale of electroweak symmetry breaking. In the absence of fine-tuning of effective operator coefficients, we find that current information on neutrino mass implies that |µν | < ∼ 10 −14 Bohr magnetons. This bound is several orders of magnitude stronger than those obtained from analyses of solar and reactor neutrino data and astrophysical observations.
10TH CONFERENCE ON THE INTERSECTIONS OF PARTICLE AND NUCLEAR PHYSICS, 2009
We examine dark matter annihilation in galaxy halos. By considering annihilation into all Standar... more We examine dark matter annihilation in galaxy halos. By considering annihilation into all Standard Model particles we show that the least detectable final states, namely neutrinos, define a strong general upper bound on the total cross section. This limit implies annihilation cannot significantly modify dark matter halo density profiles. We also consider dark matter annihilation into charged particles, which is
10TH CONFERENCE ON THE INTERSECTIONS OF PARTICLE AND NUCLEAR PHYSICS, 2009
We analyze the connection between neutrino magnetic moments and neutrino masses. Electroweak radi... more We analyze the connection between neutrino magnetic moments and neutrino masses. Electroweak radiative corrections to the neutrino mass are used to derive naturalness upper bounds on neutrino magnetic moments, generated by physics above the electroweak scale. For Dirac (Majorana) neutrinos the bound is several orders of magnitude stronger (weaker) than present experimental limits. The discovery of a neutrino magnetic moment near the present experimental sensitivity would thus suggest that neutrinos are Majorana particles. We also outline a new baryogenesis-via-leptogenesis scenario where the lepton asymmetry is generated by CP violating decays of heavy right handed neutrinos via electromagnetic dipole moment couplings.
We review the consequences of neutrino mixing in the early universe. For both active-sterile mixi... more We review the consequences of neutrino mixing in the early universe. For both active-sterile mixing or mixing between three active neutrinos only, the consequences of oscillations depend crucially upon the size of the universe's lepton number (relic neutrino asymmetry.)
Dark matter (DM) simplified models are by now commonly used by the ATLAS and CMS Collaborations t... more Dark matter (DM) simplified models are by now commonly used by the ATLAS and CMS Collaborations to interpret searches for missing transverse energy (E miss T). The coherent use of these models sharpened the LHC DM search program, especially in the presentation of its results and their comparison to DM direct-detection (DD) and indirectdetection (ID) experiments. However, the community has been aware of the limitations of the DM simplified models, in particular the lack of theoretical consistency of some of them and their restricted phenomenology leading to the relevance of only a small subset of E miss T signatures. This document from the LHC Dark Matter Working Group identifies an example of a next-generation DM model, called 2HDM+a, that provides the simplest theoretically consistent extension of the DM pseudoscalar simplified model. A comprehensive study of the phenomenology of the 2HDM+a model is presented, including a discussion of the rich and intricate pattern of mono-X signatures and the relevance of other DM as well as non-DM experiments. Based on our discussions, a set of recommended scans are proposed to explore the parameter space of the 2HDM+a model through LHC searches. The exclusion limits obtained from the proposed scans can be consistently compared to the constraints on the 2HDM+a model that derive from DD, ID and the DM relic density. Sensitivity studies 8.1 Mono-Higgs study 8.2 Mono-Z study 8.3 Sensitivity of other mono-X channels 9 Constraints from other DM experiments 9.1 DD experiments 9.2 ID experiments 10 DM relic density 10.1 Calculation 10.2 Scan results 11 Proposed parameter scans 11.1 Scan in the M a , M H = M A = M H ± plane 11.2 Scan in the M a-tan β plane 11.3 Scans in sin θ 11.4 Scan in m χ A Recasting procedure
Pacs 3.65w, 3.67a, 5.40a We consider the dynamics of a system coupled to a thermal bath, going be... more Pacs 3.65w, 3.67a, 5.40a We consider the dynamics of a system coupled to a thermal bath, going beyond the standard two-level system through the addition of an energy excitation degree of freedom. Further extensions are to systems containing many fermions, with the master equations modified to take Fermi-Dirac statistics into account, and to potentials with a time-dependent bias that induce resonant avoided crossing transitions. The limit Q → ∞, where the interaction rate with the bath is much greater than all free oscillation rates for the system, is interrogated. Two behaviors are possible: freezing (quantum Zeno effect) or synchronization (motional narrowing). We clarify the conditions that give rise to each possibility, making an explicit connection with quantum measurement theory. We compare the evolution of quantal coherence for the two cases as a function of Q, noting that full coherence is restored as Q → ∞. Using an extended master equation, the effect of system-bath interactions on entanglement in bipartite system states is computed. In particular, we show that the sychronization case sees bipartite system entanglement fully preserved in the large Q limit.
We propose a new approach to the LHC dark matter search analysis within the effective field theor... more We propose a new approach to the LHC dark matter search analysis within the effective field theory framework by utilising the K-matrix unitarisation formalism. This approach provides a reasonable estimate of the dark matter production cross section at high energies, and hence allows reliable bounds to be placed on the cutoff scale of relevant operators without running into the problem of perturbative unitarity violation. We exemplify this procedure for the effective operator D5 in monojet dark matter searches in the collinear approximation. We compare our bounds to those obtained using the truncation method and identify a parameter region where the unitarisation prescription leads to more stringent bounds.
Based on primary sequence comparisons and genomic context, Npun_F4153 (SigG)/Npun_F4154 (SapG) of... more Based on primary sequence comparisons and genomic context, Npun_F4153 (SigG)/Npun_F4154 (SapG) of the cyanobacterium Nostoc punctiforme were hypothesized to encode an ECF sigma factor/anti-sigma factor pair. Transcription of sigG increased in heterocysts and akinetes, and after EDTA treatment. Interaction between SigG and the predicted cytoplasmic domain of SapG was observed in vitro. A SigG-GFP translational fusion protein localized to the periphery of vegetative cells in vivo, but lost this association following heat stress. A sigG mutant was unable to survive envelope damage caused by heat or EDTA, but was able to form functional heterocysts. Akinetes in the mutant strain appeared normal, but these cultures were less resistant to lysozyme and cold treatments than those of the wild-type strain. The SigG in vivo regulon was determined before and during akinete differentiation using DNA microarray analysis, and found to include multiple genes with putative association to the cell envelope. Mapped promoters common to both arrays enabled identification of a SigG promoter-binding motif that was supported in vivo by reporter studies, and in vitro by runoff transcription experiments. These findings support SigG/SapG as a sigma/antisigma pair involved in repair of envelope damage resulting from exogenous sources or cellular differentiation.
International Journal of Modern Physics, Oct 30, 2007
The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiat... more The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiative corrections. We derive model-independent "naturalness" upper bounds on the magnetic moments of Dirac and Majorana neutrinos, generated by physics above the electroweak scale. For Dirac neutrinos, the bound is several orders of magnitude more stringent than present experimental limits. However, for Majorana neutrinos the magnetic moment bounds are weaker than present experimental limits if µν is generated by new physics at ∼ 1 TeV, and surpass current experimental sensitivity only for new physics scales > 10-100 TeV. The discovery of a neutrino magnetic moment near present limits would thus signify that neutrinos are Majorana particles.
Many dark matter interaction types lead to annihilation processes which suffer from p-wave suppre... more Many dark matter interaction types lead to annihilation processes which suffer from p-wave suppression or helicity suppression, rendering them subdominant to unsuppressed s-wave processes. We demonstrate that the natural inclusion of dark initial state radiation can open an unsuppressed s-wave annihilation channel, and thus provide the dominant dark matter annihilation process for particular interaction types. We illustrate this effect with the bremsstrahlung of a dark spin-0 or dark spin-1 particle from fermionic dark matter, χχ → f f φ or f f Z. The dark initial state radiation process, despite having a 3-body final state, proceeds at the same order in the new physics scale Λ as the annihilation to the 2-body final state χχ → f f. This opens an unsuppressed s-wave at lower order in Λ than the well-studied lifting of helicity suppression via Standard Model final state radiation, or virtual internal bremsstrahlung. This dark bremsstrahlung process should influence LHC and indirect detection searches for dark matter.
Journal of Cosmology and Astroparticle Physics, Nov 26, 2014
Many baryogenesis scenarios invoke the charge parity (CP) violating out-ofequilibrium decay of a ... more Many baryogenesis scenarios invoke the charge parity (CP) violating out-ofequilibrium decay of a heavy particle in order to explain the baryon asymmetry. Such scenarios will in general also allow CP violating scatterings. We study the effect of these CP violating scatterings on the final asymmetry in a neutron portal scenario. We solve the Boltzmann equations governing the evolution of the baryon number numerically and show that the CP violating scatterings play a dominant role in a significant portion of the parameter space.
Journal of Cosmology and Astroparticle Physics, Jan 11, 2018
We study a fermionic dark matter model in which the interaction of the dark and visible sectors i... more We study a fermionic dark matter model in which the interaction of the dark and visible sectors is mediated by Higgs portal type couplings. Specifically, we consider the mixing of a dark sector scalar with the scalars of a Two Higgs Doublet Model extension of the Standard Model. Given that scalar exchange will result in a spin-independent dark matter-nucleon scattering cross section, such a model is potentially subject to stringent direct detection constraints. Moreover, the addition of new charged scalars introduce non-trivial flavour constraints. Nonetheless, this model allows more freedom than a standard Higgs portal scenario involving a single Higgs doublet, and much of the interesting parameter space is not well approximated by a Simplified Model with a single scalar mediator. We perform a detailed parameter scan to determine the mass and coupling parameters which satisfy direct detection, flavour, precision electroweak, stability, and perturbativity constraints, while still producing the correct relic density through thermal freezeout.
We outline two important effects that are missing from most evaluations of the dark matter captur... more We outline two important effects that are missing from most evaluations of the dark matter capture rate in neutron stars. As dark matter scattering with nucleons in the star involves large momentum transfer, nucleon structure must be taken into account via a momentum dependence of the hadronic form factors. In addition, due to the high density of neutron star matter, we should account for nucleon interactions rather than modeling the nucleons as an ideal Fermi gas. Properly incorporating these effects is found to suppress the dark matter capture rate by up to three orders of magnitude for the heaviest stars.
We investigate the viability of electroweak baryogenesis in a model with a first order electrowea... more We investigate the viability of electroweak baryogenesis in a model with a first order electroweak phase transition induced by the addition of two gauge singlet scalars. A vector-like lepton doublet is introduced in order to provide CP violating interactions with the singlets and Standard Model leptons, and the asymmetry generation dynamics are examined using the vacuum expectation value insertion approximation. We find that such a model is readily capable of generating sufficient baryon asymmetry while satisfying electron electric dipole moment and collider phenomenology constraints.
We revisit the detection of luminous dark matter in direct detection experiments. In this scenari... more We revisit the detection of luminous dark matter in direct detection experiments. In this scenario, dark matter scatters endothermically to produce an excited state, which decays to produce a photon. We explore ways in which the electron recoil signal from the decay photon can be differentiated from other potential electron recoil signals with a narrow spectral shape. We find that larger volume/exposure xenon detectors will be unable to differentiate the signal origin without significant improvements in detector energy resolution of around an order of magnitude. We also explore what can be learned about a generic luminous dark matter signal with a higher resolution detector. Motivated by the advancements in energy resolution by solid-state detectors, we find that sub-eV resolution enables the discovery of LDM in the presence of background levels that would otherwise make observation impossible. We also find that sub-eV resolution can be used to determine the shape of the luminous dark matter decay spectrum and thus constrain the dark matter mass and velocity distribution.
We analyze the implications of neutrino masses for the magnitude of neutrino magnetic moments. By... more We analyze the implications of neutrino masses for the magnitude of neutrino magnetic moments. By considering electroweak radiative corrections to the neutrino mass, we derive modelindependent naturalness upper bounds on neutrino magnetic moments, generated by physics above the electroweak scale. For Majorana neutrinos, these bounds are weaker than present experimental limits if \iy if generated by new physics at ~ 1 TeV, and surpass current experimental sensitivity only for new physics scales > 10-100 TeV. The discovery of a neutrino magnetic moment near present limits would thus signify that neutrinos are Majorana particles.
We consider the consequences for the relic neutrino abundance if extra neutrino interactions are ... more We consider the consequences for the relic neutrino abundance if extra neutrino interactions are allowed, e.g., the coupling of neutrinos to a light (compared to mν) boson. For a wide range of couplings not excluded by other considerations, the relic neutrinos would annihilate to bosons at late times, and thus make a negligible contribution to the matter density today. This mechanism evades the neutrino mass limits arising from large scale structure.
We derive model-independent, "naturalness" upper bounds on the magnetic moments µν of Dirac neutr... more We derive model-independent, "naturalness" upper bounds on the magnetic moments µν of Dirac neutrinos generated by physics above the scale of electroweak symmetry breaking. In the absence of fine-tuning of effective operator coefficients, we find that current information on neutrino mass implies that |µν | < ∼ 10 −14 Bohr magnetons. This bound is several orders of magnitude stronger than those obtained from analyses of solar and reactor neutrino data and astrophysical observations.
10TH CONFERENCE ON THE INTERSECTIONS OF PARTICLE AND NUCLEAR PHYSICS, 2009
We examine dark matter annihilation in galaxy halos. By considering annihilation into all Standar... more We examine dark matter annihilation in galaxy halos. By considering annihilation into all Standard Model particles we show that the least detectable final states, namely neutrinos, define a strong general upper bound on the total cross section. This limit implies annihilation cannot significantly modify dark matter halo density profiles. We also consider dark matter annihilation into charged particles, which is
10TH CONFERENCE ON THE INTERSECTIONS OF PARTICLE AND NUCLEAR PHYSICS, 2009
We analyze the connection between neutrino magnetic moments and neutrino masses. Electroweak radi... more We analyze the connection between neutrino magnetic moments and neutrino masses. Electroweak radiative corrections to the neutrino mass are used to derive naturalness upper bounds on neutrino magnetic moments, generated by physics above the electroweak scale. For Dirac (Majorana) neutrinos the bound is several orders of magnitude stronger (weaker) than present experimental limits. The discovery of a neutrino magnetic moment near the present experimental sensitivity would thus suggest that neutrinos are Majorana particles. We also outline a new baryogenesis-via-leptogenesis scenario where the lepton asymmetry is generated by CP violating decays of heavy right handed neutrinos via electromagnetic dipole moment couplings.
We review the consequences of neutrino mixing in the early universe. For both active-sterile mixi... more We review the consequences of neutrino mixing in the early universe. For both active-sterile mixing or mixing between three active neutrinos only, the consequences of oscillations depend crucially upon the size of the universe's lepton number (relic neutrino asymmetry.)
Dark matter (DM) simplified models are by now commonly used by the ATLAS and CMS Collaborations t... more Dark matter (DM) simplified models are by now commonly used by the ATLAS and CMS Collaborations to interpret searches for missing transverse energy (E miss T). The coherent use of these models sharpened the LHC DM search program, especially in the presentation of its results and their comparison to DM direct-detection (DD) and indirectdetection (ID) experiments. However, the community has been aware of the limitations of the DM simplified models, in particular the lack of theoretical consistency of some of them and their restricted phenomenology leading to the relevance of only a small subset of E miss T signatures. This document from the LHC Dark Matter Working Group identifies an example of a next-generation DM model, called 2HDM+a, that provides the simplest theoretically consistent extension of the DM pseudoscalar simplified model. A comprehensive study of the phenomenology of the 2HDM+a model is presented, including a discussion of the rich and intricate pattern of mono-X signatures and the relevance of other DM as well as non-DM experiments. Based on our discussions, a set of recommended scans are proposed to explore the parameter space of the 2HDM+a model through LHC searches. The exclusion limits obtained from the proposed scans can be consistently compared to the constraints on the 2HDM+a model that derive from DD, ID and the DM relic density. Sensitivity studies 8.1 Mono-Higgs study 8.2 Mono-Z study 8.3 Sensitivity of other mono-X channels 9 Constraints from other DM experiments 9.1 DD experiments 9.2 ID experiments 10 DM relic density 10.1 Calculation 10.2 Scan results 11 Proposed parameter scans 11.1 Scan in the M a , M H = M A = M H ± plane 11.2 Scan in the M a-tan β plane 11.3 Scans in sin θ 11.4 Scan in m χ A Recasting procedure
Pacs 3.65w, 3.67a, 5.40a We consider the dynamics of a system coupled to a thermal bath, going be... more Pacs 3.65w, 3.67a, 5.40a We consider the dynamics of a system coupled to a thermal bath, going beyond the standard two-level system through the addition of an energy excitation degree of freedom. Further extensions are to systems containing many fermions, with the master equations modified to take Fermi-Dirac statistics into account, and to potentials with a time-dependent bias that induce resonant avoided crossing transitions. The limit Q → ∞, where the interaction rate with the bath is much greater than all free oscillation rates for the system, is interrogated. Two behaviors are possible: freezing (quantum Zeno effect) or synchronization (motional narrowing). We clarify the conditions that give rise to each possibility, making an explicit connection with quantum measurement theory. We compare the evolution of quantal coherence for the two cases as a function of Q, noting that full coherence is restored as Q → ∞. Using an extended master equation, the effect of system-bath interactions on entanglement in bipartite system states is computed. In particular, we show that the sychronization case sees bipartite system entanglement fully preserved in the large Q limit.
We propose a new approach to the LHC dark matter search analysis within the effective field theor... more We propose a new approach to the LHC dark matter search analysis within the effective field theory framework by utilising the K-matrix unitarisation formalism. This approach provides a reasonable estimate of the dark matter production cross section at high energies, and hence allows reliable bounds to be placed on the cutoff scale of relevant operators without running into the problem of perturbative unitarity violation. We exemplify this procedure for the effective operator D5 in monojet dark matter searches in the collinear approximation. We compare our bounds to those obtained using the truncation method and identify a parameter region where the unitarisation prescription leads to more stringent bounds.
Based on primary sequence comparisons and genomic context, Npun_F4153 (SigG)/Npun_F4154 (SapG) of... more Based on primary sequence comparisons and genomic context, Npun_F4153 (SigG)/Npun_F4154 (SapG) of the cyanobacterium Nostoc punctiforme were hypothesized to encode an ECF sigma factor/anti-sigma factor pair. Transcription of sigG increased in heterocysts and akinetes, and after EDTA treatment. Interaction between SigG and the predicted cytoplasmic domain of SapG was observed in vitro. A SigG-GFP translational fusion protein localized to the periphery of vegetative cells in vivo, but lost this association following heat stress. A sigG mutant was unable to survive envelope damage caused by heat or EDTA, but was able to form functional heterocysts. Akinetes in the mutant strain appeared normal, but these cultures were less resistant to lysozyme and cold treatments than those of the wild-type strain. The SigG in vivo regulon was determined before and during akinete differentiation using DNA microarray analysis, and found to include multiple genes with putative association to the cell envelope. Mapped promoters common to both arrays enabled identification of a SigG promoter-binding motif that was supported in vivo by reporter studies, and in vitro by runoff transcription experiments. These findings support SigG/SapG as a sigma/antisigma pair involved in repair of envelope damage resulting from exogenous sources or cellular differentiation.
International Journal of Modern Physics, Oct 30, 2007
The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiat... more The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiative corrections. We derive model-independent "naturalness" upper bounds on the magnetic moments of Dirac and Majorana neutrinos, generated by physics above the electroweak scale. For Dirac neutrinos, the bound is several orders of magnitude more stringent than present experimental limits. However, for Majorana neutrinos the magnetic moment bounds are weaker than present experimental limits if µν is generated by new physics at ∼ 1 TeV, and surpass current experimental sensitivity only for new physics scales > 10-100 TeV. The discovery of a neutrino magnetic moment near present limits would thus signify that neutrinos are Majorana particles.
Many dark matter interaction types lead to annihilation processes which suffer from p-wave suppre... more Many dark matter interaction types lead to annihilation processes which suffer from p-wave suppression or helicity suppression, rendering them subdominant to unsuppressed s-wave processes. We demonstrate that the natural inclusion of dark initial state radiation can open an unsuppressed s-wave annihilation channel, and thus provide the dominant dark matter annihilation process for particular interaction types. We illustrate this effect with the bremsstrahlung of a dark spin-0 or dark spin-1 particle from fermionic dark matter, χχ → f f φ or f f Z. The dark initial state radiation process, despite having a 3-body final state, proceeds at the same order in the new physics scale Λ as the annihilation to the 2-body final state χχ → f f. This opens an unsuppressed s-wave at lower order in Λ than the well-studied lifting of helicity suppression via Standard Model final state radiation, or virtual internal bremsstrahlung. This dark bremsstrahlung process should influence LHC and indirect detection searches for dark matter.
Journal of Cosmology and Astroparticle Physics, Nov 26, 2014
Many baryogenesis scenarios invoke the charge parity (CP) violating out-ofequilibrium decay of a ... more Many baryogenesis scenarios invoke the charge parity (CP) violating out-ofequilibrium decay of a heavy particle in order to explain the baryon asymmetry. Such scenarios will in general also allow CP violating scatterings. We study the effect of these CP violating scatterings on the final asymmetry in a neutron portal scenario. We solve the Boltzmann equations governing the evolution of the baryon number numerically and show that the CP violating scatterings play a dominant role in a significant portion of the parameter space.
Journal of Cosmology and Astroparticle Physics, Jan 11, 2018
We study a fermionic dark matter model in which the interaction of the dark and visible sectors i... more We study a fermionic dark matter model in which the interaction of the dark and visible sectors is mediated by Higgs portal type couplings. Specifically, we consider the mixing of a dark sector scalar with the scalars of a Two Higgs Doublet Model extension of the Standard Model. Given that scalar exchange will result in a spin-independent dark matter-nucleon scattering cross section, such a model is potentially subject to stringent direct detection constraints. Moreover, the addition of new charged scalars introduce non-trivial flavour constraints. Nonetheless, this model allows more freedom than a standard Higgs portal scenario involving a single Higgs doublet, and much of the interesting parameter space is not well approximated by a Simplified Model with a single scalar mediator. We perform a detailed parameter scan to determine the mass and coupling parameters which satisfy direct detection, flavour, precision electroweak, stability, and perturbativity constraints, while still producing the correct relic density through thermal freezeout.
We outline two important effects that are missing from most evaluations of the dark matter captur... more We outline two important effects that are missing from most evaluations of the dark matter capture rate in neutron stars. As dark matter scattering with nucleons in the star involves large momentum transfer, nucleon structure must be taken into account via a momentum dependence of the hadronic form factors. In addition, due to the high density of neutron star matter, we should account for nucleon interactions rather than modeling the nucleons as an ideal Fermi gas. Properly incorporating these effects is found to suppress the dark matter capture rate by up to three orders of magnitude for the heaviest stars.
Uploads
Papers by Nicole Bell