133 research outputs found

    Focus point supersymmetry in extended gauge mediation

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    We propose a small extension of the minimal gauge mediation through the combination of extended gauge mediation and conformal sequestering. We show that the focus point supersymmetry can be realized naturally, and the fine tuning is significantly reduced compared to the minimal gauge mediation and extended gauge mediation without focus point. The Higgs boson mass is around 125 GeV, the gauginos remain light, and the gluino is likely to be detected at the next run of the LHC. However, the multi-TeV squarks is out of the reach of the LHC. The numerical calculation for fine-tuning shows that this model remains natural

    No-scale ripple inflation revisited

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    We revisit the no-scale ripple inflation model, where no-scale supergravity is modified by an additional term for the inflaton field in the Kähler potential. This term not only breaks one SU(N,1) symmetry explicitly, but also plays an important role for inflation. We generalize the superpotential in the no-scale ripple inflation model slightly. There exists a discrete Z2 symmetry/parity in the scalar potential in general, which can be preserved or violated by the non-canonical nomalized inflaton kinetic term. Thus, there are three inflation paths: one parity invariant path, and the left and right paths for parity violating scenario. We show that the inflations along the parity invariant path and right path are consistent with the Planck results. However, the gavitino mass for the parity invariant path is so large that the inflation results will be invalid if we consider the inflaton supersymmetry breaking soft mass term. Thus, only the inflation along the right path gives the correct and consistent results. Notably, the tensor-to-scalar ratio in such case can be large, with a value around 0.05, which may be probed by the future Planck experiment

    Aligned natural inflation and moduli stabilization from anomalous U(1) gauge symmetries

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    To obtain natural inflation with large tensor-to-scalar ratio in string framework, we need a special moduli stabilization mechanism which can separate the masses of real and imaginary components of Kähler moduli at different scales, and achieve a trans-Planckian axion decay constant from sub-Planckian axion decay constants. In this work, we stabilize the matter fields by F-terms and the real components of Kähler moduli by D-terms of two anomalous U(1) X × U(1) A symmetries strongly at high scales, while the corresponding axions remain light due to their independence on the Fayet-Iliopoulos (FI) term in moduli stabilization. The racetrack-type axion superpotential is obtained from gaugino condensations of the hidden gauge symmetries SU(n)×SU(m) with massive matter fields in the bi-fundamental respresentations. The axion alignment via Kim-Nilles-Pelroso (KNP) mechanism corresponds to an approximate S 2 exchange symmetry of two Kähler moduli in our model, and a slightly S 2 symmetry breaking leads to the natural inflation with super-Planckian decay constant

    Observation of Electromagnetic Dalitz decays J/ψ\to P e^+e^-

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    Based on a sample of (225.3\pm2.8)\times 10^{6} J/\psi events collected with the BESIII detector, the electromagnetic Dalitz decays of J/\psi \to P e^+e^-(P=\eta'/\eta/\pi^0) are studied. By reconstructing the pseudoscalar mesons in various decay modes, the decays J/\psi \to \eta' e^+e^-, J/\psi \to \eta e^+e^- and J/\psi \to \pi^0 e^+e^- are observed for the first time. The branching fractions are determined to be \mathcal{B}(J/\psi\to \eta' e^+e^-) = (5.81\pm0.16\pm0.31)\times10^{-5}, \mathcal{B}(J/\psi\to \eta e^+e^-) = (1.16\pm0.07\pm0.06)\times10^{-5}, and \mathcal{B}(J/\psi\to \pi^0 e^+e^-)=(7.56\pm1.32\pm0.50)\times10^{-7}, where the first errors are statistical and the second ones systematic

    Search for B decays to final states with the η c meson

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    We report a search for B decays to selected final states with the η c meson: B ± → K ± η c π + π − , B ± → K ± η c ω , B ± → K ± η c η and B ± → K ± η c π 0 . The analysis is based on 772 × 10 6 B B ¯ BB B\overline{B} pairs collected at the Υ(4 S ) resonance with the Belle detector at the KEKB asymmetric-energy e + e − collider. We set 90% confidence level upper limits on the branching fractions of the studied B decay modes, independent of intermediate resonances, in the range (0 . 6–5 . 3) × 10 −4 . We also search for molecular-state candidates in the D 0 D ¯ ∗ 0 − D ¯ 0 D ∗ 0 , D 0 D ¯ 0 + D ¯ 0 D 0 D0D0D0D0,D0D0+D0D0 {D}^0{\overline{D}}^{\ast 0}-{\overline{D}}^0{D}^{\ast 0},{D}^0{\overline{D}}^0+{\overline{D}}^0{D}^0 and D ∗ 0 D ¯ ∗ 0 + D ¯ ∗ 0 D ∗ 0 D0D0+D0D0 {D}^{\ast 0}{\overline{D}}^{\ast 0}+{\overline{D}}^{\ast 0}{D}^{\ast 0} combinations, neutral partners of the Z (3900) ± and Z (4020) ± , and a poorly understood state X (3915) as possible intermediate states in the decay chain, and set 90% confidence level upper limits on the product of branching fractions to the mentioned intermediate states and decay branching fractions of these states in the range (0 . 6–6 . 9) × 10 −5

    Initial performance of the CUORE-0 experiment

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    CUORE-0 is a cryogenic detector that uses an array of tellurium dioxide bolometers to search for neutrinoless double-beta decay of 130Te . We present the first data analysis with 7.1kg·y of total TeO2 exposure focusing on background measurements and energy resolution. The background rates in the neutrinoless double-beta decay region of interest (2.47 to 2.57MeV ) and in the α background-dominated region (2.70 to 3.90MeV ) have been measured to be 0.071±0.011 and 0.019±0.002counts/(keV·kg·y) , respectively. The latter result represents a factor of 6 improvement from a predecessor experiment, Cuoricino. The results verify our understanding of the background sources in CUORE-0, which is the basis of extrapolations to the full CUORE detector. The obtained energy resolution (full width at half maximum) in the region of interest is 5.7keV . Based on the measured background rate and energy resolution in the region of interest, CUORE-0 half-life sensitivity is expected to surpass the observed lower bound of Cuoricino with one year of live time

    Measurement of branching fractions for B J / K decays and search for a narrow resonance in the J / final state

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    We report an observation of the and decays using pairs collected at the resonance with the Belle detector at the KEKB asymmetric-energy collider. We obtain the branching fractions and . We search for a new narrow charmonium(-like) state in the mass spectrum and find no significant excess. We set upper limits on the product of branching fractions, , at where a -odd partner of may exist, at and assuming their known mass and width, and over a range from 3.8 to . The obtained upper limits at 90 confidence level for , , and are , , and , respectively

    Searching for Neutrinoless Double-Beta Decay of 130Te with CUORE

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    Neutrinoless double-beta (0 <math id="M1" xmlns="http://www.w3.org/1998/Math/MathML"><mi>ν</mi><mi>β</mi><mi>β</mi></math> ) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for 0 <math id="M2" xmlns="http://www.w3.org/1998/Math/MathML"><mi>ν</mi><mi>β</mi><mi>β</mi></math> decay of 130Te using an array of 988 TeO2 crystal bolometers operated at 10 mK. The detector will contain 206 kg of 130Te and have an average energy resolution of 5 keV; the projected 0 <math id="M3" xmlns="http://www.w3.org/1998/Math/MathML"><mi>ν</mi><mi>β</mi><mi>β</mi></math> decay half-life sensitivity after five years of livetime is 1.6 × 1026 y at 1 <math id="M4" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>σ</mi></mrow></math> (9.5 × 1025 y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meV (50–130 meV). In this paper, we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach

    Production of high purity TeO2 single crystals for the study of neutrinoless double beta decay

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    High purity TeO2 crystals are produced to be used for the search for the neutrinoless double beta decay of 130Te. Dedicated production lines for raw material synthesis, crystal growth and surface processing were built compliant with radio-purity constraints specific to rare event physics experiments. High sensitivity measurements of radio-isotope concentrations in raw materials, reactants, consumables, ancillaries and intermediary products used for TeO2 crystals production are reported. Production and certification protocols are presented and resulting ready-to-use TeO2 crystals are described

    Exploring the neutrinoless double beta decay in the inverted neutrino hierarchy with bolometric detectors

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    Neutrinoless double beta decay ( 0νββ ) is one of the most sensitive probes for physics beyond the Standard Model, providing unique information on the nature of neutrinos. In this paper we review the status and outlook for bolometric 0νββ  decay searches. We summarize recent advances in background suppression demonstrated using bolometers with simultaneous readout of heat and light signals. We simulate several configurations of a future CUORE-like bolometer array which would utilize these improvements and present the sensitivity reach of a hypothetical next-generation bolometric 0νββ  experiment. We demonstrate that a bolometric experiment with the isotope mass of about 1 ton is capable of reaching the sensitivity to the effective Majorana neutrino mass ( |mee| ) of order 10–20 meV, thus completely exploring the so-called inverted neutrino mass hierarchy region. We highlight the main challenges and identify priorities for an R&D program addressing them
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