24 research outputs found

    Upper and Lower Limits on Neutralino WIMP Mass and Spin--Independent Scattering Cross Section, and Impact of New (g-2)_{mu} Measurement

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    We derive the allowed ranges of the spin--independent interaction cross section \sigsip for the elastic scattering of neutralinos on proton for wide ranges of parameters of the general Minimal Supersymmetric Standard Model. We investigate the effects of the lower limits on Higgs and superpartner masses from colliders, as well as the impact of constraints from \bsgamma and the new measurement of \gmtwo on the upper and lower limits on \sigsip. We further explore the impact of the neutralino relic density, including coannihilation, and of theoretical assumptions about the largest allowed values of the supersymmetric parameters. For μ>0\mu>0, requiring the latter to lie below 1\tev leads to \sigsip\gsim 10^{-11}\pb at \mchi\sim100\gev and \sigsip\gsim 10^{-8}\pb at \mchi\sim1\tev. When the supersymmetric parameters are allowed above 1\tev, for 440\gev \lsim \mchi\lsim 1020 \gev we derive a {\em parameter--independent lower limit} of \sigsip \gsim 2\times 10^{-12}\pb. (No similar lower limits can be set for μ<0\mu<0 nor for 1020\gev\lsim\mchi\lsim2.6\tev.) Requiring \abundchi<0.3 implies a {\em parameter--independent upper limit} \mchi\lsim2.6\tev. The new \epem--based measurement of (g2)μ(g-2)_{\mu} restricts \mchi\lsim 350\gev at 1σ1 \sigma CL and \mchi\lsim515\gev at 2σ2 \sigma CL, and implies μ>0\mu>0. The largest allowed values of \sigsip have already become accessible to recent experimental searches.Comment: LaTeX, 17 pages, 9 eps figures. Version to appear in JHE

    Flavor Changing Neutral Currents involving Heavy Quarks with Four Generations

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    We study various FCNC involving heavy quarks in the Standard Model (SM) with a sequential fourth generation. After imposing BXsγB\to X_s\gamma, BXsl+lB\to X_sl^+l^- and ZbbˉZ\to b\bar{b} constraints, we find B(Zsbˉ+sˉb){\cal B}(Z\to s\bar{b}+\bar{s}b) can be enhanced by an order of magnitude to 10710^{-7}, while tcZ,cHt\to cZ, cH decays can reach 10610^{-6}, which are orders of magnitude higher than in SM. However,these rates are still not observable for the near future.With the era of LHC approaching, we focus on FCNC decays involving fourth generation bb^\prime and tt^\prime quarks. We calculate the rates for loop induced FCNC decays bbZ,bH,bg,bγb^\prime\to bZ, bH, bg, b\gamma, as well as t^\prime\to tZ,\tH, tg, t\gamma. If Vcb|V_{cb'}| is of order Vcb0.04|V_{cb}| \simeq 0.04, tree level bcWb^\prime\to cW decay would dominate, posing a challenge since bb-tagging is less effective. For VcbVcb|V_{cb'}| \ll |V_{cb}|, btWb'\to tW would tend to dominate, while btWb'\to t^\prime W^* could also open for heavier bb', leading to thepossibility of quadruple-WW signals via bbˉbbˉW+WW+Wb'\bar b'\to b\bar b W^+W^-W^+W^-. The FCNC bbZ,bHb'\to bZ, bH decays could still dominate if mbm_{b'} is just above 200 GeV. For the case of tt', ingeneral tbWt^\prime\to bW would be dominant, hence it behaves like a heavy top. For both bb' and tt', except for the intriguing light bb' case, FCNC decays are in the 10410210^{-4} -10^{-2} range, and are quite detectable at the LHC.For a possible future ILC, we find the associated production of FCNC e+ebsˉe^+e^-\to b\bar s, tcˉt\bar c are below sensitivity, while e+ebbˉe^+e^-\to b^\prime\bar b andttˉt^\prime\bar t can be better probed.Tevatron Run-II can still probe the lighter bb' or tt' scenario. LHC would either discover the fourth generation and measure the FCNC rates, or rule out the fourth generation conclusively.Comment: 31 pages, 15 eps figures, version to appear in JHE

    WMAP-Compliant Benchmark Surfaces for MSSM Higgs Bosons

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    We explore `benchmark surfaces' suitable for studying the phenomenology of Higgs bosons in the minimal supersymmetric extension of the Standard Model (MSSM), which are chosen so that the supersymmetric relic density is generally compatible with the range of cold dark matter density preferred by WMAP and other observations. These benchmark surfaces are specified assuming that gaugino masses m_{1/2}, soft trilinear supersymmetry-breaking parameters A_0 and the soft supersymmetry-breaking contributions m_0 to the squark and slepton masses are universal, but not those associated with the Higgs multiplets (the NUHM framework). The benchmark surfaces may be presented as M_A-tan_beta planes with fixed or systematically varying values of the other NUHM parameters, such as m_0, m_{1/2}, A_0 and the Higgs mixing parameter mu. We discuss the prospects for probing experimentally these benchmark surfaces at the Tevatron collider, the LHC, the ILC, in B physics and in direct dark-matter detection experiments. An Appendix documents developments in the FeynHiggs code that enable the user to explore for her/himself the WMAP-compliant benchmark surfaces.Comment: Minor corrections, references added. 43 pages, 10 figures. Version to appear in JHE

    Investigation of demand response on Dutch network

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    This report looks into the network challenges that can be observed in simulation of dutch distributuin grid. The analysis has been performed in two different consideration, first considering network as it is currently. Thus, report analyses the relative critical nodes and suggest testing plan for INCREASE Project. Second, four different types of DR programs has been applied to the network. Preliminary simple DR approach is used to observe the change in network behavior. Lastly, the final conclusion are made

    Energy Flexometer:an effective implementation of internet of things for market-based demand response in an energy management system

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    Market-based control mechanism (MCM) needs the IoT environment to fully explore flexibility potential from the end-users to offer to involved actors of the smart energy system. On the other hand, many IoT based energy management systems are already available to a market. This paper presents an approach to connect the current demand-driven (top-down) energy management system (EMS) with a market-driven (bottom-up) demand response program. To this end, this paper considers multi-agent system (MAS) to realize the approach and introduces the concept and standardize design of Energy Flexometer. It is described as an elemental agent of the approach. Proposed by authors Energy Flexometer consists of three different functional blocks, which are formulated as an IoT platform according to the LonWorks standard. Moreover, the paper also performs an evaluation study in order to validate the proposed concept and design.</p

    Energy Flexometer: an effective implementation of internet of things for market-based demand response in an energy management system

    No full text
    Market-based control mechanism (MCM) needs the IoT environment to fully explore flexibility potential from the end-users to offer to involved actors of the smart energy system. On the other hand, many IoT based energy management systems are already available to a market. This paper presents an approach to connect the current demand-driven (top-down) energy management system (EMS) with a market-driven (bottom-up) demand response program. To this end, this paper considers multi-agent system (MAS) to realize the approach and introduces the concept and standardize design of Energy Flexometer. It is described as an elemental agent of the approach. Proposed by authors Energy Flexometer consists of three different functional blocks, which are formulated as an IoT platform according to the LonWorks standard. Moreover, the paper also performs an evaluation study in order to validate the proposed concept and design

    Learning technique for real-time congestion management in an active distribution networks

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    During the last few decades, the concept of demand response (DR) in the energy sector has gained substantial momentum. Research has led to a range of DR solutions. These solutions mostly differ in their applications, the hosting power system, the energy market etc. Moreover, as per the EU directive, DR aggregators should be allowed to trade DR alongside supply in both day-ahead and real time electricity markets. Meanwhile, independent aggregators do not consider physical limitations of a network, thus setting up new a challenges for network operation. In this paper, an active learning technique for real-time congestion management is proposed to tackle this challenge. This enables distributed system operator (DSO) to incenticize independent aggregators efficiently in order to use DR for overloading mitigation. Lastly, a case study is simulated which verifies the performance of a new approach for congestion management
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