1,752 research outputs found

    Higgs production at future e+eβˆ’e^+e^- colliders in the Georgi-Machacek model

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    We study how the dominant single and double SM-like Higgs (hh) production at future e+eβˆ’e^+e^- colliders is modified in the Georgi-Machacek (GM) model. On imposing theoretical, indirect and direct constraints, significant deviations of hh-couplings from their SM values are still possible; for instance, the Higgs-gauge coupling coupling can be corrected by a factor ΞΊhVV∈[0.93,1.15]\kappa_{hVV}\in[0.93,1.15] in the allowed parameter space. For the Higgs-strahlung e+eβˆ’β†’hZe^+e^-\to hZ and vector boson fusion processes e+eβˆ’β†’hΞ½Ξ½Λ‰,Β he+eβˆ’e^+e^-\to h\nu\bar{\nu},~he^+e^-, the cross section could increase by 32%32\% or decrease by 13%13\%. In the case of associated production with a top quark pair e+eβˆ’β†’httΛ‰e^+e^-\to ht\bar{t}, the cross section can be enhanced up to several times when the custodial triplet scalar H30H_3^0 is resonantly produced. In the meanwhile, the double Higgs production e+eβˆ’β†’hhZΒ (hhΞ½Ξ½Λ‰)e^+e^-\to hhZ~(hh\nu\bar{\nu}) can be maximally enhanced by one order of magnitude at the resonant H1,30H_{1,3}^0 production. We also include exclusion limits expected from future LHC runs at higher energy and luminosity and discuss their further constraints on the relevant model parameters. We find that the GM model can result in likely measurable deviations of Higgs production from the SM at future e+eβˆ’e^+e^- colliders.Comment: 31 pages, 17 figures, published in JHE

    Hunting for Heavy Majorana Neutrinos with Lepton Number Violating Signatures at LHC

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    The neutrinophilic two-Higgs-doublet model (Ξ½\nu2HDM) provides a natural way to generate tiny neutrino mass from interactions with the new doublet scalar Φν\Phi_\nu (HΒ±,Β H,Β AH^\pm,~H,~A) and singlet neutrinos NRN_R of TeV scale. In this paper, we perform detailed simulations for the lepton number violating (LNV) signatures at LHC arising from cascade decays of the new scalars and neutrinos with the mass order mNR<mΦνm_{N_R}<m_{\Phi_\nu}. Under constraints from lepton flavor violating processes and direct collider searches, their decay properties are explored and lead to three types of LNV signatures: 2β„“Β±4j+ET2\ell^\pm 4j+\cancel{E}_T, 3β„“Β±4j+ET3\ell^\pm 4j+\cancel{E}_T, and 3β„“Β±β„“βˆ“4j3\ell^\pm\ell^\mp 4j. We find that the same-sign trilepton signature 3β„“Β±4j+ET3\ell^\pm4j+\cancel{E}_T is quite unique and is the most promising discovery channel at the high-luminosity LHC. Our analysis also yields the 95%95\% C.L. exclusion limits in the plane of the Φν\Phi_\nu and NRN_R masses at 13 (14) TeV LHC with an integrated luminosity of 100~(3000)/fb.Comment: 31 pages, 17 figures, 6 tables; v2: added a few refs and updated one ref, without other change

    Giant negative magnetoresistance induced by the chiral anomaly in individual Cd3As2 nanowires

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    Cd3As2 is a newly booming Dirac semimetal with linear dispersion along all three momentum directions and can be viewed as 3D analog of graphene. As breaking of either time reversal symmetry or spatial inversion symmetry, the Dirac semimetal is believed to transform into Weyl semimetal with exotic chiral anomaly effect, while the experimental evidence of the chiral anomaly is still missing in Cd3As2. Here we report the magneto-transport properties of individual Cd3As2 nanowires. Large negative magnetoresistance (MR) with magnitude of -63% at 60 K and -11% at 300 K are observed when the magnetic field is parallel with the electric field direction, giving the evidence of the chiral magnetic effect in Cd3As2 nanowires. In addition, the critical magnetic field BC, where there is an extremum of the negative MR, increases with increasing temperature. As the first observation of chiral anomaly induced negative MR in Cd3As2 nanowires, it may offer valuable insights for low dimensional physics in Dirac semimetals.Comment: 4 figure

    ServeNet: A Deep Neural Network for Web Services Classification

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    Automated service classification plays a crucial role in service discovery, selection, and composition. Machine learning has been widely used for service classification in recent years. However, the performance of conventional machine learning methods highly depends on the quality of manual feature engineering. In this paper, we present a novel deep neural network to automatically abstract low-level representation of both service name and service description to high-level merged features without feature engineering and the length limitation, and then predict service classification on 50 service categories. To demonstrate the effectiveness of our approach, we conduct a comprehensive experimental study by comparing 10 machine learning methods on 10,000 real-world web services. The result shows that the proposed deep neural network can achieve higher accuracy in classification and more robust than other machine learning methods.Comment: Accepted by ICWS'2

    Excited Heavy Quarkonium Production at the LHC through WW-Boson Decays

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    Sizable amount of heavy-quarkonium events can be produced through WW-boson decays at the LHC. Such channels will provide a suitable platform to study the heavy-quarkonium properties. The "improved trace technology", which disposes the amplitude M{\cal M} at the amplitude-level, is helpful for deriving compact analytical results for complex processes. As an important new application, in addition to the production of the lower-level Fock states ∣(QQβ€²Λ‰)[1S]>|(Q\bar{Q'})[1S]> and ∣(QQβ€²Λ‰)[1P]>|(Q\bar{Q'})[1P]>, we make a further study on the production of higher-excited ∣(QQβ€²Λ‰)>|(Q\bar{Q'})>-quarkonium Fock states ∣(QQβ€²Λ‰)[2S]>|(Q\bar{Q'})[2S]>, ∣(QQβ€²Λ‰)[3S]>|(Q\bar{Q'})[3S]> and ∣(QQβ€²Λ‰)[2P]>|(Q\bar{Q'})[2P]>. Here ∣(QQβ€²Λ‰)>|(Q\bar{Q'})> stands for the ∣(ccΛ‰)>|(c\bar{c})>-charmonium, ∣(cbΛ‰)>|(c\bar{b})>-quarkonium and ∣(bbΛ‰)>|(b\bar{b})>-bottomonium respectively. We show that sizable amount of events for those higher-excited states can also be produced at the LHC. Therefore, we need to take them into consideration for a sound estimation.Comment: 7 pages, 9 figures and 6 tables. Typo errors are corrected, more discussions and two new figures have been adde
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