2,258 research outputs found

    Academic institutional repositories in China: A survey of CALIS member libraries

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    Purpose: China Academic Library &amp; Information System (CALIS) planned to launch an institutional repository (IR) project to promote IR development and open access at colleges and universities in China. In order to get to know the current state of IRs in academic institutions, with the help of Peking University Library, CALIS Administrative Center conducted this survey.Design/methodology/approach: We conducted an online survey of CALIS member libraries.Findings: Firstly, the development of IRs at China's colleges and universities is still in its infancy. Secondly, the Chinese colleges and universities have reached a consensus on the objective for having an IR. Thirdly, they are having high expectations of IR&nbsp;functions. Fourthly, they prefer to establish a centralized IR system at a minimum cost. Finally, there are both similarities and differences between the Chinese academic institutions and their counterparts in other countries in the state of IR development.Research limitations: The questionnaire needs to be improved because there is a lack of enough questions for those who do not plan to build an IR. Comparatively lower rate of valid questionnaire return can affect the accuracy of the results. It is hard to go into an in-depth discussion only based on the data collected from this questionnaire survey, and consequently, the findings from the survey can hardly present an accurate and comprehensive picture of the current state of IR development in the academic sector in China.Practical implications: The survey results provide essential foundation for CALIS IR project, and meanwhile the research can serve as a reference source for the future studies of the development of IRs at China's colleges and universities.Originality/value: It is the first national survey focused on the development of IRs in academic institutions in China.</p

    Supernova Constraints on Massive (Pseudo)Scalar Coupling to Neutrinos

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    In this paper we derive constraints on the emission of a massive (pseudo)scalar SS from annihilation of neutrinos in the core of supernovae through the dimension-4 coupling ννS\nu\nu S, as well as the effective dimension-5 operator 1Λ(νν)(SS)\frac{1}{\Lambda}(\nu\nu)(SS). While most of earlier studies have focused on massless or ultralight scalars, our analysis involves scalar with masses of order eV−GeV\mathrm{eV- GeV} which can be copiously produced during the explosion of supernovae, whose core temperature is generally of order T∼O(10)T\sim \mathcal{O}(10) MeV. From the luminosity and deleptonization arguments regarding the observation of SN1987A, we exclude a large range of couplings 10−12≲∣gαβ∣≲10−5 10^{-12} \lesssim {|g_{\alpha\beta}|}\lesssim 10^{-5} for the dimension-4 case, depending on the neutrino flavours involved and the scalar mass. In the case of dimension-5 operator, for a scalar mass from MeV to 100 MeV the coupling hαβh_{\alpha\beta} get constrained from 10−610^{-6} to 10−210^{-2}, with the cutoff scale explicitly set Λ=1\Lambda = 1 TeV. We finally show that if the neutrino burst of a nearby supernova explosion is detected by Super-Kamiokande and IceCube, the constraints will be largely reinforced.Comment: 17 pages, 4 figures, version to appear in JCA

    SWAPHI: Smith-Waterman Protein Database Search on Xeon Phi Coprocessors

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    The maximal sensitivity of the Smith-Waterman (SW) algorithm has enabled its wide use in biological sequence database search. Unfortunately, the high sensitivity comes at the expense of quadratic time complexity, which makes the algorithm computationally demanding for big databases. In this paper, we present SWAPHI, the first parallelized algorithm employing Xeon Phi coprocessors to accelerate SW protein database search. SWAPHI is designed based on the scale-and-vectorize approach, i.e. it boosts alignment speed by effectively utilizing both the coarse-grained parallelism from the many co-processing cores (scale) and the fine-grained parallelism from the 512-bit wide single instruction, multiple data (SIMD) vectors within each core (vectorize). By searching against the large UniProtKB/TrEMBL protein database, SWAPHI achieves a performance of up to 58.8 billion cell updates per second (GCUPS) on one coprocessor and up to 228.4 GCUPS on four coprocessors. Furthermore, it demonstrates good parallel scalability on varying number of coprocessors, and is also superior to both SWIPE on 16 high-end CPU cores and BLAST+ on 8 cores when using four coprocessors, with the maximum speedup of 1.52 and 1.86, respectively. SWAPHI is written in C++ language (with a set of SIMD intrinsics), and is freely available at http://swaphi.sourceforge.net.Comment: A short version of this paper has been accepted by the IEEE ASAP 2014 conferenc

    TeV Scale Universal Seesaw, Vacuum Stability and Heavy Higgs

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    We discuss the issue of vacuum stability of standard model by embedding it within the TeV scale left-right universal seesaw model (called SLRM in the text). This model has only two coupling parameters (λ1,λ2)(\lambda_1, \lambda_2) in the Higgs potential and only two physical neutral Higgs bosons (h,H)(h, H). We explore the range of values for (λ1,λ2)(\lambda_1, \lambda_2) for which the light Higgs boson mass Mh=126M_h=126 GeV and the vacuum is stable for all values of the Higgs fields. Combining with the further requirement that the scalar self couplings remain perturbative till typical GUT scales of order 101610^{16} GeV, we find (i) an upper and lower limit on the second Higgs (H)(H) mass to be within the range: 0.4≤MHvR≤0.70.4 \leq \frac{M_H}{v_R}\leq 0.7, where the vRv_R is the parity breaking scale and (ii) that the heavy vector-like top, bottom and τ\tau partner fermions (P3,N3,E3P_3, N_3, E_3) mass have an upper bound MP3,N3,E3≤vRM_{P_3, N_3, E_3} \leq v_R. We discuss some phenomenological aspects of the model pertaining to LHC.Comment: 21 pages, 7 figures, some typos corrected and references updated, accepted for publication in JHE

    LHC Accessible Second Higgs Boson in the Left-Right Model

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    A second Higgs doublet arises naturally as a parity partner of the standard model (SM) Higgs, once SM is extended to its left-right symmetric version (LRSM) to understand the origin of parity violation in weak interactions as well as to accommodate small neutrino masses via the seesaw mechanism. The flavor changing neutral Higgs (FCNH) effects in the minimal version of this model (LRSM), however, push the second Higgs mass to more than 15 TeV making it inaccessible at the LHC. Furthermore since the second Higgs mass is directly linked to the WRW_R mass, discovery of a "low" mass WRW_R (MWR≤5−6M_{W_R}\leq 5-6 TeV) at the LHC would require values for some Higgs self couplings larger than one. In this paper we present an extension of LRSM by adding a vector-like SU(2)RSU(2)_R quark doublet which weakens the FCNH constraints allowing the second Higgs mass to be near or below TeV and a third neutral Higgs below 3 TeV for a WRW_R mass below 5 TeV. It is then possible to search for these heavier Higgs bosons at the LHC, without conflicting with FCNH constraints. A right handed WRW_R mass in the few TeV range is quite natural in this class of models without having to resort to large scalar coupling parameters. The CKM mixings are intimately linked to the vector-like quark mixings with the known quarks, which is the main reason why the constraints on the second Higgs mass is relaxed. We present a detailed theoretical and phenomenological analysis of this extended LR model and point out some tests as well as its potential for discovery of a second Higgs at the LHC. Two additional features of the model are: (i) a 5/3 charged quark and (ii) a fermionic top partner with masses in the TeV range.Comment: 22 pages, 4 figures, lots of stuff moved to the appendices, errors and typos corrected, version to appear in PR

    Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions

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    The type-II seesaw mechanism with an isospin-triplet scalar ΔL\Delta_L provides one of the most compelling explanations for the observed smallness of neutrino masses. The triplet contains a doubly-charged component HL±±H_L^{\pm\pm}, which dominantly decays to either same-sign dileptons or to a pair of WW bosons, depending on the size of the triplet vacuum expectation value. However, there exists a range of Yukawa couplings fLf_L of the triplet to the charged leptons, wherein a relatively light HL±±H_L^{\pm\pm} tends to be long-lived, giving rise to distinct displaced-vertex signatures at the high-energy colliders. We find that the displaced vertex signals from the leptonic decays HL±±→ℓα±ℓβ±H_L^{\pm\pm} \to \ell_\alpha^\pm \ell_\beta^\pm could probe a broad parameter space with 10−10≲∣fL∣≲10−610^{-10} \lesssim |f_L| \lesssim 10^{-6} and 45.6 GeV <MHL±±≲200< M_{H_L^{\pm\pm}} \lesssim 200 GeV at the high-luminosity LHC. Similar sensitivity can also be achieved at a future 1 TeV e+e−e^+e^- collider. The mass reach can be extended to about 500 GeV at a future 100 TeV proton-proton collider. Similar conclusions apply for the right-handed triplet HR±±H_R^{\pm\pm} in the TeV-scale left-right symmetric models, which provide a natural embedding of the type-II seesaw. We show that the displaced vertex signals are largely complementary to the prompt same-sign dilepton pair searches at the LHC and the low-energy, high-intensity/precision measurements, such as neutrinoless double beta decay, charged lepton flavor violation, electron and muon anomalous magnetic moments, muonium oscillation and M{\o}ller scattering.Comment: 49 pages, 25 figures and 2 tables, minor changes, version to appear in JHE
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