Gilly Elor | Massachusetts Institute of Technology (MIT) (original) (raw)
Papers by Gilly Elor
Physical Review D, 2015
If dark matter is embedded in a non-trivial dark sector, it may annihilate and decay to lighter d... more If dark matter is embedded in a non-trivial dark sector, it may annihilate and decay to lighter dark-sector states which subsequently decay to the Standard Model. Such scenarios -with annihilation followed by cascading dark-sector decays -can explain the apparent excess GeV gamma-rays identified in the central Milky Way, while evading bounds from dark matter direct detection experiments. Each 'step' in the cascade will modify the observable signatures of dark matter annihilation and decay, shifting the resulting photons and other final state particles to lower energies and broadening their spectra. We explore, in a model-independent way, the effect of multi-step dark-sector cascades on the preferred regions of parameter space to explain the GeV excess. We find that the broadening effects of multi-step cascades can admit final states dominated by particles that would usually produce too sharply peaked photon spectra; in general, if the cascades are hierarchical (each particle decays to substantially lighter particles), the preferred mass range for the dark matter is in all cases 20-150 GeV. Decay chains that have nearly-degenerate steps, where the products are close to half the mass of the progenitor, can admit much higher DM masses. We map out the region of mass/cross-section parameter space where cascades (degenerate, hierarchical or a combination) can fit the signal, for a range of final states. In the current work, we study multi-step cascades in the context of explaining the GeV excess, but many aspects of our results are general and can be extended to other applications. PACS numbers: 95.35.+d, 12.60.-i; MIT-CTP/4647
Journal of High Energy Physics, 2012
Naturalness in supersymmetry (SUSY) is under siege by increasingly stringent LHC constraints, but... more Naturalness in supersymmetry (SUSY) is under siege by increasingly stringent LHC constraints, but natural electroweak symmetry breaking still remains the most powerful motivation for superpartner masses within experimental reach. If naturalness is the wrong criterion then what determines the mass scale of the superpartners? We motivate supersymmetry by (1) gauge coupling unification, (2) dark matter, and (3) precision b − τ Yukawa unification. We show that for an LSP that is a bino-Higgsino admixture, these three requirements lead to an upper-bound on the stop and sbottom masses in the several TeV regime because the threshold correction to the bottom mass at the superpartner scale is required to have a particular size. For tan β ≈ 50, which is needed for t−b−τ unification, the stops must be lighter than 2.8 TeV when A t has the opposite sign of the gluino mass, as is favored by renormalization group scaling. For lower values of tan β, the top and bottom squarks must be even lighter. Yukawa unification plus dark matter implies that superpartners are likely in reach of the LHC, after the upgrade to 14 (or 13) TeV, independent of any considerations of naturalness. We present a model-independent, bottom-up analysis of the SUSY parameter space that is simultaneously consistent with Yukawa unification and the hint for m h = 125 GeV. We study the flavor and dark matter phenomenology that accompanies this Yukawa unification. A large portion of the parameter space predicts that the branching fraction for B s → µ + µ − will be observed to be significantly lower than the SM value.
Journal of High Energy Physics, 2012
KamLAND is 1000-ton liquid scintillator detector which uses the prompt and delayed signals from i... more KamLAND is 1000-ton liquid scintillator detector which uses the prompt and delayed signals from inverse beta decay to detect electron anti-neutrinos produced in nuclear reactors. KamLAND has made the first observation of the disappearance of reactor electron anti-neutrinos. The largest contribution to the systematic uncertainty in KamLAND is the fiducial volume uncertainty (4.7 % out of a total 6.5 % ). Until now the detector has been calibrated using gamma-ray sources of known energy deployed along the detector's vertical axis. A new 4π calibration system allows for off-axis source deployment throughout the entire fiducial volume. The 4 π system is expected to reduce the fiducial volume uncertainty from 4.7 % to ˜ 1-2 % , and improve KamLAND's sensitivity in the determination of the mass-difference parameter δm12^2 . The 4π system is currently in the initial stages of off-axis deployment. An off-line calculation is used to predict the location of the gamma-ray sources within the detector. The calculation takes into account the systems geometry, buoyancy effects in the liquid scintillator, and gravitational deflection of the 4π pole from its neutral axis (deflection correction incorporates both a theoretical model, and survey data). Comparison of the predicted source location with the vertex reconstructed using the KamLAND analysis software, allows for an investigation of the biases in the reconstruction procedure.
We explore an alternative mechanism for the production of gravitino dark matter whereby relic gra... more We explore an alternative mechanism for the production of gravitino dark matter whereby relic gravitinos originate from the decays of superpartners which are still in thermal equilibrium, i.e. via freeze-in. Contributions to the gravitino abundance from freeze-in can easily dominate over those from thermal scattering over a broad range of parameter space, e.g. when the scalar superpartners are heavy. Because the relic abundance from freeze-in is independent of the reheating temperature after inflation, collider measurements may be used to unambiguously reconstruct the freeze-in origin of gravitinos. In particular, if gravitino freeze-in indeed accounts for the present day dark matter abundance, then the lifetime of the next-to-lightest superpartner is uniquely fixed by the superpartner spectrum.
We revisit the cosmology of the supersymmetric QCD axion, highlighting the existence of a serious... more We revisit the cosmology of the supersymmetric QCD axion, highlighting the existence of a serious cosmological axino problem that is fully analogous to the gravitino problem of overclosure via thermal production. A general analysis implies that the QCD axino has a mass greater than or equal to that of the gravitino in the absence of unnatural fine-tuning or sequestering. As a consequence, bounds from thermal gravitino and QCD axino production are complementary in parameter space, and together provide a quite stringent limit on the reheating temperature after inflation given by TR < 10 3 −10 6 GeV for an axion decay constant of fa = 10 9 −10 12 GeV. Motivated by this result, we explore the cosmology of gravitino LSP and axino NLSP at low TR and present three realistic scenarios for dark matter.
Journal of High Energy Physics, 2011
We present a systematic cosmological study of a universe in which the visible sector is coupled, ... more We present a systematic cosmological study of a universe in which the visible sector is coupled, albeit very weakly, to a hidden sector comprised of its own set of particles and interactions. Assuming that dark matter (DM) resides in the hidden sector and is charged under a stabilizing symmetry shared by both sectors, we determine all possible origins of weak-scale DM allowed within this broad framework. We show that DM can arise only through a handful of mechanisms, lending particular focus to Freeze-Out and Decay and Freeze-In, as well as their variations involving late time re-annihilations of DM and DM particle anti-particle asymmetries. Much like standard Freeze-Out, where the abundance of DM depends only on the annihilation cross-section of the DM particle, these mechanisms depend only on a very small subset of physical parameters, many of which may be measured directly at the LHC. In particular, we show that each DM production mechanism is associated with a distinctive window in lifetimes and cross-sections for particles which may be produced in the near future. We evaluate prospects for employing the LHC to definitively reconstruct the origin of DM in a companion paper.
Journal of High Energy Physics, 2011
We consider a broad class of supersymmetric theories in which dark matter (DM) is the lightest su... more We consider a broad class of supersymmetric theories in which dark matter (DM) is the lightest superpartner (LSP) of a hidden sector that couples very weakly to visible sector fields. Portal interactions connecting visible and hidden sectors mediate the decay of the lightest observable superpartner (LOSP) into the LSP, allowing the LHC to function as a spectacular probe of the origin of hidden sector DM. As shown in a companion paper, this general two-sector framework allows only for a handful of DM production mechanisms, each of which maps to a distinctive window in lifetimes and cross-sections for the LOSP. In the present work we perform a systematic collider study of LOSP candidates and portal interactions, and for each case evaluate the prospects for successfully reconstructing the origin of DM at the LHC. If, for instance, DM arises from Freeze-Out and Decay, this may be verified if the LOSP is a bino or right-handed slepton decaying to the LSP through a variety of portal interactions, and with an annihilation cross-section within a narrow range. On the other hand, the Freeze-In mechanism may be verified for a complimentary set of LOSP candidates, and within a narrow range of LOSP lifetimes. In all cases, the LOSP is relatively long-lived on collider time scales, leading to events with displaced vertices. Furthermore, scenarios with a charged or colored LOSP are particularly promising.
We present a systematic cosmological study of a universe in which the visible sector is coupled, ... more We present a systematic cosmological study of a universe in which the visible sector is coupled, albeit very weakly, to a hidden sector comprised of its own set of particles and interactions. Assuming that dark matter (DM) resides in the hidden sector and is charged under a stabilizing symmetry shared by both sectors, we determine all possible origins of weak-scale DM allowed within this broad framework. We show that DM can arise only through a handful of mechanisms, lending particular focus to Freeze-Out and Decay and Freeze-In, as well as their variations involving late time re-annihilations of DM and DM particle anti-particle asymmetries. Much like standard Freeze-Out, where the abundance of DM depends only on the annihilation cross-section of the DM particle, these mechanisms depend only on a very small subset of physical parameters, many of which may be measured directly at the LHC. In particular, we show that each DM production mechanism is associated with a distinctive window in lifetimes and cross-sections for particles which may be produced in the near future. We evaluate prospects for employing the LHC to definitively reconstruct the origin of DM in a companion paper.
Physical Review D, 2010
We explore the possibility that both the weak scale and the thermal relic dark matter abundance a... more We explore the possibility that both the weak scale and the thermal relic dark matter abundance are environmentally selected in a multiverse. An underlying supersymmetric theory containing the states of the MSSM and singlets, with supersymmetry and R symmetry broken at unified scales, has just two realistic low energy effective theories. One theory, (SM +w), is the Standard Model augmented only by the wino, having a mass near 3 TeV, and has a Higgs boson mass in the range of (127 -142) GeV. The other theory, (SM +h/s), has Higgsinos and a singlino added to the Standard Model. The Higgs boson mass depends on the single new Yukawa coupling of the theory, y, and is near 141 GeV for small y but grows to be as large as 210 GeV as this new coupling approaches strong coupling at high energies. Much of the parameter space of this theory will be probed by direct detection searches for dark matter that push two orders of magnitude below the present bounds; furthermore, the dark matter mass and cross section on nucleons are correlated with the Higgs boson mass. The indirect detection signal of monochromatic photons from the galactic center is computed, and the range of parameters that may be accessible to LHC searches for trilepton events is explored. Taking a broader view, allowing the possibility of R symmetry protection to the TeV scale or axion dark matter, we find four more theories: (SM + axion), two versions of Split Supersymmetry, and the E-MSSM, where a little supersymmetric hierarchy is predicted. The special Higgs mass value of (141 ± 2) GeV appears in symmetry limits of three of the six theories, (SM + axion), (SM +w) and (SM +h/s), motivating a comparison of other signals of these three theories.
Physical Review D, 2010
We explore the possibility that both the weak scale and the thermal relic dark matter abundance a... more We explore the possibility that both the weak scale and the thermal relic dark matter abundance are environmentally selected in a multiverse. An underlying supersymmetric theory containing the states of the MSSM and singlets, with supersymmetry and R symmetry broken at unified scales, has just two realistic low energy effective theories. One theory, (SM +w), is the Standard Model augmented only by the wino, having a mass near 3 TeV, and has a Higgs boson mass in the range of (127 -142) GeV. The other theory, (SM +h/s), has Higgsinos and a singlino added to the Standard Model. The Higgs boson mass depends on the single new Yukawa coupling of the theory, y, and is near 141 GeV for small y but grows to be as large as 210 GeV as this new coupling approaches strong coupling at high energies. Much of the parameter space of this theory will be probed by direct detection searches for dark matter that push two orders of magnitude below the present bounds; furthermore, the dark matter mass and cross section on nucleons are correlated with the Higgs boson mass. The indirect detection signal of monochromatic photons from the galactic center is computed, and the range of parameters that may be accessible to LHC searches for trilepton events is explored. Taking a broader view, allowing the possibility of R symmetry protection to the TeV scale or axion dark matter, we find four more theories: (SM + axion), two versions of Split Supersymmetry, and the E-MSSM, where a little supersymmetric hierarchy is predicted. The special Higgs mass value of (141 ± 2) GeV appears in symmetry limits of three of the six theories, (SM + axion), (SM +w) and (SM +h/s), motivating a comparison of other signals of these three theories.
We consider a broad class of supersymmetric theories in which dark matter (DM) is the lightest su... more We consider a broad class of supersymmetric theories in which dark matter (DM) is the lightest superpartner (LSP) of a hidden sector that couples very weakly to visible sector fields. Portal interactions connecting visible and hidden sectors mediate the decay of the lightest observable superpartner (LOSP) into the LSP, allowing the LHC to function as a spectacular probe of the origin of hidden sector DM. As shown in a companion paper, this general two-sector framework allows only for a handful of DM production mechanisms, each of which maps to a distinctive window in lifetimes and cross-sections for the LOSP. In the present work we perform a systematic collider study of LOSP candidates and portal interactions, and for each case evaluate the prospects for successfully reconstructing the origin of DM at the LHC. If, for instance, DM arises from Freeze-Out and Decay, this may be verified if the LOSP is a bino or right-handed slepton decaying to the LSP through a variety of portal interactions, and with an annihilation cross-section within a narrow range. On the other hand, the Freeze-In mechanism may be verified for a complimentary set of LOSP candidates, and within a narrow range of LOSP lifetimes. In all cases, the LOSP is relatively long-lived on collider time scales, leading to events with displaced vertices. Furthermore, scenarios with a charged or colored LOSP are particularly promising.
Physical Review D, 2015
If dark matter is embedded in a non-trivial dark sector, it may annihilate and decay to lighter d... more If dark matter is embedded in a non-trivial dark sector, it may annihilate and decay to lighter dark-sector states which subsequently decay to the Standard Model. Such scenarios -with annihilation followed by cascading dark-sector decays -can explain the apparent excess GeV gamma-rays identified in the central Milky Way, while evading bounds from dark matter direct detection experiments. Each 'step' in the cascade will modify the observable signatures of dark matter annihilation and decay, shifting the resulting photons and other final state particles to lower energies and broadening their spectra. We explore, in a model-independent way, the effect of multi-step dark-sector cascades on the preferred regions of parameter space to explain the GeV excess. We find that the broadening effects of multi-step cascades can admit final states dominated by particles that would usually produce too sharply peaked photon spectra; in general, if the cascades are hierarchical (each particle decays to substantially lighter particles), the preferred mass range for the dark matter is in all cases 20-150 GeV. Decay chains that have nearly-degenerate steps, where the products are close to half the mass of the progenitor, can admit much higher DM masses. We map out the region of mass/cross-section parameter space where cascades (degenerate, hierarchical or a combination) can fit the signal, for a range of final states. In the current work, we study multi-step cascades in the context of explaining the GeV excess, but many aspects of our results are general and can be extended to other applications. PACS numbers: 95.35.+d, 12.60.-i; MIT-CTP/4647
Journal of High Energy Physics, 2012
Naturalness in supersymmetry (SUSY) is under siege by increasingly stringent LHC constraints, but... more Naturalness in supersymmetry (SUSY) is under siege by increasingly stringent LHC constraints, but natural electroweak symmetry breaking still remains the most powerful motivation for superpartner masses within experimental reach. If naturalness is the wrong criterion then what determines the mass scale of the superpartners? We motivate supersymmetry by (1) gauge coupling unification, (2) dark matter, and (3) precision b − τ Yukawa unification. We show that for an LSP that is a bino-Higgsino admixture, these three requirements lead to an upper-bound on the stop and sbottom masses in the several TeV regime because the threshold correction to the bottom mass at the superpartner scale is required to have a particular size. For tan β ≈ 50, which is needed for t−b−τ unification, the stops must be lighter than 2.8 TeV when A t has the opposite sign of the gluino mass, as is favored by renormalization group scaling. For lower values of tan β, the top and bottom squarks must be even lighter. Yukawa unification plus dark matter implies that superpartners are likely in reach of the LHC, after the upgrade to 14 (or 13) TeV, independent of any considerations of naturalness. We present a model-independent, bottom-up analysis of the SUSY parameter space that is simultaneously consistent with Yukawa unification and the hint for m h = 125 GeV. We study the flavor and dark matter phenomenology that accompanies this Yukawa unification. A large portion of the parameter space predicts that the branching fraction for B s → µ + µ − will be observed to be significantly lower than the SM value.
Journal of High Energy Physics, 2012
KamLAND is 1000-ton liquid scintillator detector which uses the prompt and delayed signals from i... more KamLAND is 1000-ton liquid scintillator detector which uses the prompt and delayed signals from inverse beta decay to detect electron anti-neutrinos produced in nuclear reactors. KamLAND has made the first observation of the disappearance of reactor electron anti-neutrinos. The largest contribution to the systematic uncertainty in KamLAND is the fiducial volume uncertainty (4.7 % out of a total 6.5 % ). Until now the detector has been calibrated using gamma-ray sources of known energy deployed along the detector's vertical axis. A new 4π calibration system allows for off-axis source deployment throughout the entire fiducial volume. The 4 π system is expected to reduce the fiducial volume uncertainty from 4.7 % to ˜ 1-2 % , and improve KamLAND's sensitivity in the determination of the mass-difference parameter δm12^2 . The 4π system is currently in the initial stages of off-axis deployment. An off-line calculation is used to predict the location of the gamma-ray sources within the detector. The calculation takes into account the systems geometry, buoyancy effects in the liquid scintillator, and gravitational deflection of the 4π pole from its neutral axis (deflection correction incorporates both a theoretical model, and survey data). Comparison of the predicted source location with the vertex reconstructed using the KamLAND analysis software, allows for an investigation of the biases in the reconstruction procedure.
We explore an alternative mechanism for the production of gravitino dark matter whereby relic gra... more We explore an alternative mechanism for the production of gravitino dark matter whereby relic gravitinos originate from the decays of superpartners which are still in thermal equilibrium, i.e. via freeze-in. Contributions to the gravitino abundance from freeze-in can easily dominate over those from thermal scattering over a broad range of parameter space, e.g. when the scalar superpartners are heavy. Because the relic abundance from freeze-in is independent of the reheating temperature after inflation, collider measurements may be used to unambiguously reconstruct the freeze-in origin of gravitinos. In particular, if gravitino freeze-in indeed accounts for the present day dark matter abundance, then the lifetime of the next-to-lightest superpartner is uniquely fixed by the superpartner spectrum.
We revisit the cosmology of the supersymmetric QCD axion, highlighting the existence of a serious... more We revisit the cosmology of the supersymmetric QCD axion, highlighting the existence of a serious cosmological axino problem that is fully analogous to the gravitino problem of overclosure via thermal production. A general analysis implies that the QCD axino has a mass greater than or equal to that of the gravitino in the absence of unnatural fine-tuning or sequestering. As a consequence, bounds from thermal gravitino and QCD axino production are complementary in parameter space, and together provide a quite stringent limit on the reheating temperature after inflation given by TR < 10 3 −10 6 GeV for an axion decay constant of fa = 10 9 −10 12 GeV. Motivated by this result, we explore the cosmology of gravitino LSP and axino NLSP at low TR and present three realistic scenarios for dark matter.
Journal of High Energy Physics, 2011
We present a systematic cosmological study of a universe in which the visible sector is coupled, ... more We present a systematic cosmological study of a universe in which the visible sector is coupled, albeit very weakly, to a hidden sector comprised of its own set of particles and interactions. Assuming that dark matter (DM) resides in the hidden sector and is charged under a stabilizing symmetry shared by both sectors, we determine all possible origins of weak-scale DM allowed within this broad framework. We show that DM can arise only through a handful of mechanisms, lending particular focus to Freeze-Out and Decay and Freeze-In, as well as their variations involving late time re-annihilations of DM and DM particle anti-particle asymmetries. Much like standard Freeze-Out, where the abundance of DM depends only on the annihilation cross-section of the DM particle, these mechanisms depend only on a very small subset of physical parameters, many of which may be measured directly at the LHC. In particular, we show that each DM production mechanism is associated with a distinctive window in lifetimes and cross-sections for particles which may be produced in the near future. We evaluate prospects for employing the LHC to definitively reconstruct the origin of DM in a companion paper.
Journal of High Energy Physics, 2011
We consider a broad class of supersymmetric theories in which dark matter (DM) is the lightest su... more We consider a broad class of supersymmetric theories in which dark matter (DM) is the lightest superpartner (LSP) of a hidden sector that couples very weakly to visible sector fields. Portal interactions connecting visible and hidden sectors mediate the decay of the lightest observable superpartner (LOSP) into the LSP, allowing the LHC to function as a spectacular probe of the origin of hidden sector DM. As shown in a companion paper, this general two-sector framework allows only for a handful of DM production mechanisms, each of which maps to a distinctive window in lifetimes and cross-sections for the LOSP. In the present work we perform a systematic collider study of LOSP candidates and portal interactions, and for each case evaluate the prospects for successfully reconstructing the origin of DM at the LHC. If, for instance, DM arises from Freeze-Out and Decay, this may be verified if the LOSP is a bino or right-handed slepton decaying to the LSP through a variety of portal interactions, and with an annihilation cross-section within a narrow range. On the other hand, the Freeze-In mechanism may be verified for a complimentary set of LOSP candidates, and within a narrow range of LOSP lifetimes. In all cases, the LOSP is relatively long-lived on collider time scales, leading to events with displaced vertices. Furthermore, scenarios with a charged or colored LOSP are particularly promising.
We present a systematic cosmological study of a universe in which the visible sector is coupled, ... more We present a systematic cosmological study of a universe in which the visible sector is coupled, albeit very weakly, to a hidden sector comprised of its own set of particles and interactions. Assuming that dark matter (DM) resides in the hidden sector and is charged under a stabilizing symmetry shared by both sectors, we determine all possible origins of weak-scale DM allowed within this broad framework. We show that DM can arise only through a handful of mechanisms, lending particular focus to Freeze-Out and Decay and Freeze-In, as well as their variations involving late time re-annihilations of DM and DM particle anti-particle asymmetries. Much like standard Freeze-Out, where the abundance of DM depends only on the annihilation cross-section of the DM particle, these mechanisms depend only on a very small subset of physical parameters, many of which may be measured directly at the LHC. In particular, we show that each DM production mechanism is associated with a distinctive window in lifetimes and cross-sections for particles which may be produced in the near future. We evaluate prospects for employing the LHC to definitively reconstruct the origin of DM in a companion paper.
Physical Review D, 2010
We explore the possibility that both the weak scale and the thermal relic dark matter abundance a... more We explore the possibility that both the weak scale and the thermal relic dark matter abundance are environmentally selected in a multiverse. An underlying supersymmetric theory containing the states of the MSSM and singlets, with supersymmetry and R symmetry broken at unified scales, has just two realistic low energy effective theories. One theory, (SM +w), is the Standard Model augmented only by the wino, having a mass near 3 TeV, and has a Higgs boson mass in the range of (127 -142) GeV. The other theory, (SM +h/s), has Higgsinos and a singlino added to the Standard Model. The Higgs boson mass depends on the single new Yukawa coupling of the theory, y, and is near 141 GeV for small y but grows to be as large as 210 GeV as this new coupling approaches strong coupling at high energies. Much of the parameter space of this theory will be probed by direct detection searches for dark matter that push two orders of magnitude below the present bounds; furthermore, the dark matter mass and cross section on nucleons are correlated with the Higgs boson mass. The indirect detection signal of monochromatic photons from the galactic center is computed, and the range of parameters that may be accessible to LHC searches for trilepton events is explored. Taking a broader view, allowing the possibility of R symmetry protection to the TeV scale or axion dark matter, we find four more theories: (SM + axion), two versions of Split Supersymmetry, and the E-MSSM, where a little supersymmetric hierarchy is predicted. The special Higgs mass value of (141 ± 2) GeV appears in symmetry limits of three of the six theories, (SM + axion), (SM +w) and (SM +h/s), motivating a comparison of other signals of these three theories.
Physical Review D, 2010
We explore the possibility that both the weak scale and the thermal relic dark matter abundance a... more We explore the possibility that both the weak scale and the thermal relic dark matter abundance are environmentally selected in a multiverse. An underlying supersymmetric theory containing the states of the MSSM and singlets, with supersymmetry and R symmetry broken at unified scales, has just two realistic low energy effective theories. One theory, (SM +w), is the Standard Model augmented only by the wino, having a mass near 3 TeV, and has a Higgs boson mass in the range of (127 -142) GeV. The other theory, (SM +h/s), has Higgsinos and a singlino added to the Standard Model. The Higgs boson mass depends on the single new Yukawa coupling of the theory, y, and is near 141 GeV for small y but grows to be as large as 210 GeV as this new coupling approaches strong coupling at high energies. Much of the parameter space of this theory will be probed by direct detection searches for dark matter that push two orders of magnitude below the present bounds; furthermore, the dark matter mass and cross section on nucleons are correlated with the Higgs boson mass. The indirect detection signal of monochromatic photons from the galactic center is computed, and the range of parameters that may be accessible to LHC searches for trilepton events is explored. Taking a broader view, allowing the possibility of R symmetry protection to the TeV scale or axion dark matter, we find four more theories: (SM + axion), two versions of Split Supersymmetry, and the E-MSSM, where a little supersymmetric hierarchy is predicted. The special Higgs mass value of (141 ± 2) GeV appears in symmetry limits of three of the six theories, (SM + axion), (SM +w) and (SM +h/s), motivating a comparison of other signals of these three theories.
We consider a broad class of supersymmetric theories in which dark matter (DM) is the lightest su... more We consider a broad class of supersymmetric theories in which dark matter (DM) is the lightest superpartner (LSP) of a hidden sector that couples very weakly to visible sector fields. Portal interactions connecting visible and hidden sectors mediate the decay of the lightest observable superpartner (LOSP) into the LSP, allowing the LHC to function as a spectacular probe of the origin of hidden sector DM. As shown in a companion paper, this general two-sector framework allows only for a handful of DM production mechanisms, each of which maps to a distinctive window in lifetimes and cross-sections for the LOSP. In the present work we perform a systematic collider study of LOSP candidates and portal interactions, and for each case evaluate the prospects for successfully reconstructing the origin of DM at the LHC. If, for instance, DM arises from Freeze-Out and Decay, this may be verified if the LOSP is a bino or right-handed slepton decaying to the LSP through a variety of portal interactions, and with an annihilation cross-section within a narrow range. On the other hand, the Freeze-In mechanism may be verified for a complimentary set of LOSP candidates, and within a narrow range of LOSP lifetimes. In all cases, the LOSP is relatively long-lived on collider time scales, leading to events with displaced vertices. Furthermore, scenarios with a charged or colored LOSP are particularly promising.