Recent Developments in Supersymmetric and Hidden Sector Dark Matter
New results which correlate SUSY dark matter with LHC signals are presented, and a brief review of recent developments in supersymmetric and hidden sector dark matter is given. It is shown that the direct detection of dark matter is very sensitive to the hierarchical SUSY sparticle spectrum and the spectrum is very useful in distinguishing models. It is shown that the prospects of the discovery of neutralino dark matter are very bright on the “Chargino Wall” due to a copious number of model points on the Wall, where the NLSP is the Chargino, and the spin independent neutralino‐proton cross section is maintained at high values in the 10−44 cm2 range for neutralino masses up to ∼850 GeV. It is also shown that the direct detection of dark matter along with lepton plus jet signatures and missing energy provide dual, and often complementary, probes of supersymmetry. Finally, we discuss an out of the box possibility for dark matter, which includes dark matter from the hidden sector, which could either consist o...

title: The Stueckelberg Extension and Milli Weak and Milli Charged Dark Matter
abstract: A overview is given of the recent developments in the U(1)X Stueckelberg extensions of the Standard Model and of MSSM where all the Standard Model particles are neutral under the U(1)X, but an axion which is absorbed is charged under both U(1)X and U(1)Y and acts as the connector field coupling the Standard Model sector with the Stueckelberg sector. Coupled with the usual Higgs mechanism that breaks the SU(2)L×U(1)Y gauge symmetry, this scenario produces mixings in the neutral gauge boson sector generating an extra Z′ boson. The couplings of the extra Z′ to the Standard Model particles are milli weak but its couplings to the hidden sector matter, defined as matter that couples only to the gauge field of U(1)X, can be of normal electro‐weak strength. It is shown that such extensions, aside from the possibility of leading to a sharp Z′ resonance, lead to two new types of dark matter: milli weak (or extra weak) and milli charged. An analysis of the relic density shows that the WMAP‐3 constraints can be satis...

title: Explaining PAMELA and WMAP data through coannihilations in extended SUGRA with collider implications
abstract: The PAMELA positron excess is analyzed within the framework of nonuniversal supergravity (SUGRA) models with an extended $U(1{)}^{n}$ gauge symmetry in the hidden sector leading to neutralino dark matter with either a mixed Higgsino-wino lightest $R$-parity odd supersymmetric particle (LSP) or an essentially pure wino-dominated LSP. The Higgsino-wino LSP can produce the observed PAMELA positron excess and satisfy relic density constraints in the extended class of models due to a near degeneracy of the mass spectrum of the extended neutralino sector with the LSP mass. The simultaneous satisfaction of the WMAP relic density data and the PAMELA data is accomplished through a coannihilation mechanism (${B}_{\mathrm{Co}}\ensuremath{-}\mathrm{\text{mechanism}}$), and leads to predictions of a neutralino and a chargino in the mass range (180--200) GeV as well as low-lying sparticles accessible at colliders. We show that the models are consistent with the antiproton constraints from PAMELA as well as the photon flux data from EGRET and FERMI-LAT. Predictions for the scalar neutralino-proton cross section relevant for the direct detection of dark matter are also discussed and signatures at the LHC for these PAMELA inspired models are analyzed. It is shown that the mixed Higgsino-wino LSP model will be discoverable with as little as $1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data and is thus a prime candidate for discovery in the low luminosity runs at the LHC.

title: LHC constraints on dark matter with (130 GeV) gamma ray lines
abstract: Dark matter annihilation into photons in our galaxy would constitute an exciting indirect signal of its existence, as underscored by tentative evidence for 130 GeV dark matter in Fermi/LAT data. Models that give a large annihilation cross section into photons typically require the dark matter to couple to, or be composed of, new charged particles, that can be produced in colliders. We consider the LHC constraints on some representative models of these types, including the signals of same-sign dileptons, opposite-sign dileptons, events mimicking the production and decay of excited leptons, four-photon events, resonant production of composite vectors decaying into two photons, and monophoton events.

title: Light Higgses at the Tevatron and at the LHC and Observable Dark Matter in SUGRA and D Branes
abstract: Sparticle landscapes in mSUGRA, in SUGRA models with nonuniversalities (NUSUGRA), and in D-brane models are analyzed. The analysis exhibits the existence of Higgs Mass Patterns (HPs) (for μ > 0 ) where the CP odd Higgs could be the next heavier particle beyond the LSP and sometimes even lighter than the LSP. It is shown that the Higgs production cross sections from the HPs are typically the largest enhancing the prospects for their detection at the LHC. Indeed it is seen that the recent Higgs production limits from CDF/DO are beginning to put constraints on the HPs. It is also seen that the B s → μ + μ − limits constrain the HPs more stringently. Predictions of the Higgs production cross sections for these patterns at the LHC are made. We compute the neutralino–proton cross sections σ ( χ ˜ 1 0 p ) for dark matter experiments and show that the largest σ ( χ ˜ 1 0 p ) also arise from the HPs and further that the HPs and some of the other patterns are beginning to be constrained by the most recent data from CDMS and from Xenon10 experiments. Finally, it is shown that the prospects are bright for the discovery of dark matter with σ ( χ ˜ 1 0 p ) in the range 10 − 44 ± 0.5 cm 2 due to a “Wall” consisting of a copious number of parameter points in the Chargino Patterns (CPs) where the chargino is the NLSP. The Wall, which appears in all models considered (mSUGRA, NUSUGRA and D-branes) and runs up to about a TeV in LSP mass, significantly enhances the chances for the observation of dark matter by SuperCDMS, ZEPLIN-MAX, or LUX experiments which are expected to achieve a sensitivity of 10 −45 cm 2 or more.

title: Scattering properties of dark atoms and molecules
abstract: There has been renewed interest in the possibility that dark matter exists in the form of atoms, analogous to those of the visible world. An important input for understanding the cosmological consequences of dark atoms is their self-scattering. Making use of results from atomic physics for the potentials between hydrogen atoms, we compute the low-energy elastic scattering cross sections for dark atoms. We find an intricate dependence upon the ratio of the dark proton to electron mass, allowing for the possibility to "design" low-energy features in the cross section. Dependences upon other parameters, namely the gauge coupling and reduced mass, scale out of the problem by using atomic units. We derive constraints on the parameter space of dark atoms by demanding that their scattering cross section does not exceed bounds from dark matter halo shapes. We discuss the formation of molecular dark hydrogen in the universe, and determine the analogous constraints on the model when the dark matter is predominantly in molecular form.

title: Light neutralino dark matter: direct/indirect detection and collider searches
abstract: A bstractWe study the neutralino being the Lightest Supersymmetric Particle (LSP) as a cold Dark Matter (DM) candidate with a mass less than 40 GeV in the framework of the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM). We find that with the current collider constraints from LEP, the Tevatron and the LHC, there are three types of light DM solutions consistent with the direct/indirect searches as well as the relic abundance considerations: (i) A1, H1-funnels, (ii) stau coannihilation and (iii) sbottom coannihilation. Type-(i) may take place in any theory with a light scalar (or pseudo-scalar) near the LSP pair threshold; while Type-(ii) and (iii) could occur in the framework of Minimal-Supersymmetric-Standard-Model (MSSM) as well. We present a comprehensive study on the properties of these solutions and point out their immediate relevance to the experiments of the underground direct detection such as superCDMS and LUX/LZ, and the astro-physical indirect search such as Fermi-LAT. We also find that the decays of the SM-like Higgs boson may be modified appreciably and the new decay channels to the light SUSY particles may be sizable. The new light CP-even and CP-odd Higgs bosons will decay to a pair of LSPs as well as other observable final states, leading to interesting new Higgs phenomenology at colliders. For the light sfermion searches, the signals would be very challenging to observe at the LHC given the current bounds. However, a high energy and high luminosity lepton collider, such as the ILC, would be able to fully cover these scenarios by searching for events with large missing energy plus charged tracks or displaced vertices.

title: Dark matter and Higgs bosons in the MSSM
abstract: A bstractWe investigate dark matter (DM) in the context of the minimal supersymmetric extension of the standard model (MSSM). We scan through the MSSM parameter space and search for solutions that (a) are consistent with the Higgs discovery and other collider searches; (b) satisfy the flavor constraints from B physics; (c) give a DM candidate with the correct thermal relic density; and (d) are allowed by the DM direct detection experiments. For the surviving models with our parameter scan, we find the following features: (1) The DM candidate is largely a Bino-like neutralino with non-zero but less than 20% Wino and Higgsino fractions; (2) The relic density requirement clearly pins down the solutions from the Z and Higgs resonances (Z, h, H, A funnels) and co-annihilations; (3) Future direct search experiments will likely fully cover the Z, h funnel regions, and H, A funnel regions as well except for the “blind spots”; (4) Future indirect search experiments will be more sensitive to the CP-odd Higgs exchange due to its s-wave nature; (5) The branching fraction for the SM-like Higgs decay to DM can be as high as 10%, while those from heavier Higgs decays to neutralinos and charginos can be as high as 20%. We show that collider searches provide valuable information complementary to what may be obtained from direct detections and astroparticle observations. In particular, the Z- and h-funnels with a predicted low LSP mass should be accessible at future colliders. Overall, the Higgs bosons may play an essential role as the portal to the dark sector.

title: Production of e, mu and tau pairs in untagged two-photon collisions at LEP
abstract: The two-photon collision reaction e+e- --> e+e-l+l- has been studied at root(s) ~ 91 GeV using the L3 detector at LEP for l = e, muon , tau. We have analysed untagged configurations where the two photons are quasi-real. Good agreement is found between our measurements and the order alpha**4 QED expectation.

title: First observation of the M1 transition $\psi(3686)\to \gamma\eta_c(2S)$
abstract: Using a sample of 106 million \psi(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: \psi(3686)\to\gamma\eta_c(2S). Analyses of the processes \psi(2S)\to \gamma\eta_c(2S) with \eta_c(2S)\to \K_S^0 K\pi and K^+K^-\pi^0 gave an \eta_c(2S) signal with a statistical significance of greater than 10 standard deviations under a wide range of assumptions about the signal and background properties. The data are used to obtain measurements of the \eta_c(2S) mass (M(\eta_c(2S))=3637.6\pm 2.9_\mathrm{stat}\pm 1.6_\mathrm{sys} MeV/c^2), width (\Gamma(\eta_c(2S))=16.9\pm 6.4_\mathrm{stat}\pm 4.8_\mathrm{sys} MeV), and the product branching fraction (\BR(\psi(3686)\to \gamma\eta_c(2S))\times \BR(\eta_c(2S)\to K\bar K\pi) = (1.30\pm 0.20_\mathrm{stat}\pm 0.30_\mathrm{sys})\times 10^{-5}). Combining our result with a BaBar measurement of \BR(\eta_c(2S)\to K\bar K \pi), we find the branching fraction of the M1 transition to be \BR(\psi(3686)\to\gamma\eta_c(2S)) = (6.8\pm 1.1_\mathrm{stat}\pm 4.5_\mathrm{sys})\times 10^{-4}.

title: The BES upgrade
abstract: The Beijing Spectrometer (BES) detector is a general purpose solenoid detector at the Beijing Electron Positron Collider (BEPC) in Beijing, China, that has collected large numbers of J/ψ, ψ′, D s , D and τ events. In this paper, we describe the recent upgrade of the initial BES detector (BESI) to the improved BESII detector.