9,890 research outputs found

    Probing gauge-phobic heavy Higgs bosons at high energy hadron colliders

    Get PDF
    We study the probe of the gauge-phobic (or nearly gauge-phobic) heavy Higgs bosons (GPHB) at high energy hadron colliders including the 14 TeV LHC and the 50 TeV Super Proton-Proton Collider (SppC). We take the process pp→ttˉttˉpp\to t\bar t t\bar t, and study it at the hadron level including simulating the jet formation and top quark tagging (with jet substructure). We show that, for a GPHB with MH<800M^{}_H<800 GeV, MHM^{}_H can be determined by adjusting the value of MHM^{}_H in the theoretical pT(b1)p^{}_T(b_1) distribution to fit the observed pT(b1)p^{}_T(b_1) distribution, and the resonance peak can be seen at the SppC for MHM^{}_H=800 GeV and 1 TeV.Comment: 6 pages, with 7 eps files for 7 figure

    Water voyage from Quabbin to Boston

    Get PDF
    This thesis focus on investigating on revealing the powerful Quabbin to Boston water system. In Boston, whenever we turn on our tap, our shower head, there is water coming out. Being driven by the curiosity of want to know the source of the water, the research eventually get to know the Quabbin Reservoir. Being fascinated by the giant body of water which provides water for people of the big Boston, in phase one the research begins with finding the hidden story of the displaced people who lost their land because of Quabbin reservoir. However, the way of the researching cannot show the sublimity of Quabbin, so in phase 2 the researcher then continues investigating the components of the whole system during which she found that the hidden part of the system-----the giant size of the infrastructures of this system are really impressive and make her feel very sublime, so she decides to show the sublime feeling of the infrastructure via design. She also does a form study based on the way water flows under the force of gravity. Finally in phase three, the researcher starts to work on identifying the issues of the site, by applying the framework on the site, she is able to come up with some strategies. Also, by extracting the size elements of the pipes and layouting them on the site, combining with the structure she got from the water flow form study, she is able to come up with a design which works mainly on the landform for revealing the system and provide space for people to use

    Enols as intermediates in nitrosation and halogenation of malonamide and malonic acid

    Get PDF
    Catalysed nitrosation of malonamide(MA) was carried out in aqueous acidic solution at 25ºC. In the presence of bromide ion as a catalyst, the reaction was always first order in [HNO(_2)] despite the changes in acidity. However, the kinetic behaviour of SCN(^-) catalysed reaction varied from first order to zero order with [SCN(^-)], suggesting that the reaction occurs via an enol intermediate and the rate limiting step can move from enolisation to nitrosation under certain conditions. lodination and bromination of malonamide were investigated in aqueous acidic solution at 25ºC. At low acidity, the iodination of malonamide was zero order in [I2], which is in good agreement with the proposed mechanism where the reaction occurs via an enol intermediate and enolisation is the rate limiting step. The deuterium isotope effect on iodination of malonamide was also examined and the result strongly confirmed the existence of enol form in the reaction. The acid catalysed enolisation can be expressed as follows: At higher acidity and lower [I2] reaction was first order in [I2], when now iodination of the end is rate limiting. When enolisation is rate limiting the rate equation was established as Rate=k(_obs)=k(_1)[H(^+)][MA] The values of enolisation rate constant k(_1) (3.72(±0.4)xl0(^-3) l.mol(^-1).s(^-1)) is significantly larger than that measured for simple ketones such as acetone (3.8xl0(^-5) 1-mol(^-1).s(^-1)), reflecting the greater acidity of the central hydrogen atom in malonamide structure brought about by the second –CONH(_2) group or possibly the greater concentration of the O-protonated intermediate. Bromination was perfectly first-order in [Br(_2)] at all acidities. Attempts to achieve rate-limiting enolisation by increasing [Br(_2)] were only partially successful. Perfect zero order behaviour could not be obtained. A possible explanation is that dibromination occurs in the reaction. By combination of the above three reactions, Kg the equilibrium constant of enolisation of malonamide was estimated as 4(±2)xl0(^-10), with an assumption that the rate limiting step of electrophilic addition occurs at the encounter limit. The bromination of malonic acid (MAL) was studied under pH 1.0-4.65 at 25ºC. The reaction was zero order in [Br(_2)] and the plots of k(_o)/[MAL](_T) vs [MAL](_T) were linear, implying that the enolisation reaction is via the malonate ion catalysed pathway

    Artificial-Noise-Aided Physical Layer Phase Challenge-Response Authentication for Practical OFDM Transmission

    Full text link
    Recently, we have developed a PHYsical layer Phase Challenge-Response Authentication Scheme (PHY-PCRAS) for independent multicarrier transmission. In this paper, we make a further step by proposing a novel artificial-noise-aided PHY-PCRAS (ANA-PHY-PCRAS) for practical orthogonal frequency division multiplexing (OFDM) transmission, where the Tikhonov-distributed artificial noise is introduced to interfere with the phase-modulated key for resisting potential key-recovery attacks whenever a static channel between two legitimate users is unfortunately encountered. Then, we address various practical issues for ANA-PHY-PCRAS with OFDM transmission, including correlation among subchannels, imperfect carrier and timing recoveries. Among them, we show that the effect of sampling offset is very significant and a search procedure in the frequency domain should be incorporated for verification. With practical OFDM transmission, the number of uncorrelated subchannels is often not sufficient. Hence, we employ a time-separated approach for allocating enough subchannels and a modified ANA-PHY-PCRAS is proposed to alleviate the discontinuity of channel phase at far-separated time slots. Finally, the key equivocation is derived for the worst case scenario. We conclude that the enhanced security of ANA-PHY-PCRAS comes from the uncertainty of both the wireless channel and introduced artificial noise, compared to the traditional challenge-response authentication scheme implemented at the upper layer.Comment: 33 pages, 13 figures, submitted for possible publicatio
    • …
    corecore