Pair Production of Doubly-Charged Scalars: Neutrino Mass Constraints and Signals at the LHC

We study the pair production of doubly charged Higgs bosons at the Large Hadron Collider (LHC), assuming the doubly charged Higgs to be part of an SU(2)_L triplet which generates Majorana masses for left-handed neutrinos. Such pair-production has the advantage that it is not constrained by the triplet vacuum expectation value, which tends to make the single production rate rather small. We point out that, in addition to the Drell-Yan (DY) production mechanism, two-photon processes also contribute to H++H++ production at a level comparable to the QCD corrections to the DY channel. Decays of the doubly charged Higgs into both the l+l+ and W+W+ modes are studied in detail to optimize the signal observation over the backgrounds. Doubly charged scalars should be observable at the LHC with 300 fb^-1 integrated luminosity in the ll channel upto the mass range of 1 TeV even with a branching fraction of about 60 %, and in the WW channel upto a mass of 700 GeV. Such a doubly charged Higgs, if it is a member of a triplet generating neutrino masses,cannot be long-lived on the scale of collider detectors although it might lead to a displaced secondary vertex during its decay if it is lighter than about 250 GeV.Comment: revtex4, 23 pages, 14 figures, version published in Physical Review

GeV Majorana Neutrinos in Top-quark Decay at the LHC

We explore the \Delta L=2 same-sign dilepton signal from top-quark decay via a Majorana neutrino at the LHC in the top anti-top pair production samples. The signature is same-sign dilepton plus multi-jets with no significant missing energy. The most optimistic region lies where the Majorana neutrino mass is between 15-65 GeV. For 300 fb^-1 integrated luminosity, it is possible to probe S_{ij}, the effective mixing parameter, to order of 10^-5.Comment: 15 pages, 8 figure

Contraints on radiative dark-matter decay from the cosmic microwave background

If dark matter decays to electromagnetically-interacting particles, it can inject energy into the baryonic gas and thus affect the processes of recombination and reionization. This leaves an imprint on the cosmic microwave background (CMB): the large-scale polarization is enhanced, and the small-scale temperature fluctuation is damped. We use the WMAP three-year data combined with galaxy surveys to constrain radiatively decaying dark matter. Our new limits to the dark-matter decay width are about ten times stronger than previous limits. For dark-matter lifetimes that exceed the age of the Universe, a limit of $\zeta \Gamma_{\chi} < 1.7 \times 10^{-25} s^{-1}$ (95% CL) is derived, where $\zeta$ is the efficiency of converting decay energy into ionization energy. Limits for lifetimes short compared with the age of the Universe are also derived. We forecast improvements expected from the Planck satellite.Comment: replaced with version published on PR

The Design of B2B E-commerce System Based on MVC Model and J2EE

In the paper, the architecture of J2EE and the method of development system with J2EE were described. Among of these technologies, Web application with the MVC model to develop was emphasized. On the base of the B2B business trade flow, requirement analysis was discussed in detail. It emphasized that the modeling and system designed and implemented. A B2B e-commerce system of four-layer architecture by EJB component technology was established. Key words: B2B E-Commerce system; J2EE technology; EJB component; MVC mode

The impact of core self-evaluations and person-job fit on work-related outcomes

IntroductionThe aim of this study is to explore the mediating effect of emotional exhaustion (EE) between core self-evaluations (CSE), person-job fit (PJ fit) and service recovery performance (SRP). The current research also examines whether organizational dehumanization (OD) moderates the relationship between two antecedents, EE and SRP.MethodsWe collected time-lagged and multi-source data from star-rated hotels in three cities in China. In particular, direct supervisors of frontline employees (FLEs) rated their SRP (N = 32 supervisors and their 212 immediate employees). The hypotheses were gauged via PROCESS (version 3.4).ResultsThe results indicate that CSE and PJ fit alleviate FLEs’ EE, which subsequently advances their SRP. OD moderates the direct impact of two antecedents on EE and SRP. Moreover, OD moderates the indirect influence of two antecedents on SRP through EE.DiscussionThe hospitality literature currently lacks an in-depth understanding of the underlying mechanism through which CSE and PJ fit affect FLEs’ SRP. This study incorporates EE as a mediator of the CSE’s and PJ fit’s impact on SRP, and to the authors’ knowledge, this is the first attempt to evaluate whether OD moderates the direct influence of CSE and PJ fit on SRP and the indirect impact of CSE and PJ fit on the aforementioned outcome via EE

Properties of single-layer graphene doped by nitrogen with different concentrations

Graphene has vast promising applications on the nanoelectronics and spintronics because of its unique magnetic and electronic properties. Making use of an ab initio spin-polarized density functional theory, implemented by the method of Heyd-Scuseria-Ernzerhof 06(HSE06) hybrid functional, the properties of nitrogen substitutional dopants in semi-metal monolayer graphene were investigated. We found from our calculation, that introducing nitrogen doping would possibly break energy degeneracy with respect to spin(spin symmetry breaking) at some doping concentrations with proper dopant configurations. The spin symmetry breaking would cause spin-polarized effects, which induce magnetic response in graphene. This paper systematically analyzed the dependence of magnetic moments and band gaps in graphene on doping concentrations of nitrogen atoms, as well as dopant configurations.Comment: 17pages,4figures,5table

Study on Trust Countermeasures of SMEs RJVs Based on Reputation Angle of View

Research Joint Ventures (RJVs) is an effective way for SMEs(small and medium enterprises) independent innovation. In order to realize cooperation across the organization and border-crossing, SMEs RJVs must consider how to reduce cost, improve cooperative effect cooperation, and meanwhile guarantee the flexibility of SMEs. The essence of SMEs RJVs is cooperation, and cooperation is closely linked with trust. Trust is the basis for the cooperation. In order to maintain the stable cooperation relationship and good operation, SMEs RJVs require establishing incentive mechanism for the members’ cooperation. The reputation of organizational members’ cooperation is undoubtedly an effective incentive. By using the KMPW reputation model of complete information dynamic game, we can analyze the trust problems of SMEs RJVs under the condition with information asymmetry. Moreover, the KMPW reputation model can also disclose and transmit the trust information about the enterprises effectively.Key words: SMEs; Research Joint Ventures; Reputation mode

PointHuman: Reconstructing Clothed Human from Point Cloud of Parametric Model

It is very difficult to accomplish the 3D reconstruction of the clothed human body from a single RGB image, because the 2D image lacks the representation information of the 3D human body, especially for the clothed human body. In order to solve this problem, we introduced a priority scheme of different body parts spatial information and proposed PointHuman network. PointHuman combines the spatial feature of the parametric model of the human body with the implicit functions without expressive restrictions. In PointHuman reconstruction framework, we use Point Transformer to extract the semantic spatial feature of the parametric model of the human body to regularize the implicit function of the neural network, which extends the generalization ability of the neural network to complex human poses and various styles of clothing. Moreover, considering the ambiguity of depth information, we estimate the depth of the parameterized model after point cloudization, and obtain an offset depth value. The offset depth value improves the consistency between the parameterized model and the neural implicit function, and accuracy of human reconstruction models. Finally, we optimize the restoration of the parametric model from a single image, and propose a depth perception method. This method further improves the estimation accuracy of the parametric model and finally improves the effectiveness of human reconstruction. Our method achieves competitive performance on the THuman dataset