2,258 research outputs found
Academic institutional repositories in China: A survey of CALIS member libraries
Purpose: China Academic Library & 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 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
In this paper we derive constraints on the emission of a massive
(pseudo)scalar from annihilation of neutrinos in the core of supernovae
through the dimension-4 coupling , as well as the effective
dimension-5 operator . While most of earlier
studies have focused on massless or ultralight scalars, our analysis involves
scalar with masses of order which can be copiously produced
during the explosion of supernovae, whose core temperature is generally of
order MeV. From the luminosity and deleptonization
arguments regarding the observation of SN1987A, we exclude a large range of
couplings 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 get constrained from to ,
with the cutoff scale explicitly set 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
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
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 in
the Higgs potential and only two physical neutral Higgs bosons . We
explore the range of values for for which the light
Higgs boson mass 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 GeV,
we find (i) an upper and lower limit on the second Higgs mass to be
within the range: , where the is the
parity breaking scale and (ii) that the heavy vector-like top, bottom and
partner fermions () mass have an upper bound . 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
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 mass, discovery of a "low" mass (
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
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
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
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
The type-II seesaw mechanism with an isospin-triplet scalar
provides one of the most compelling explanations for the observed smallness of
neutrino masses. The triplet contains a doubly-charged component
, which dominantly decays to either same-sign dileptons or to a
pair of bosons, depending on the size of the triplet vacuum expectation
value. However, there exists a range of Yukawa couplings of the triplet
to the charged leptons, wherein a relatively light 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 could probe a
broad parameter space with and 45.6
GeV GeV at the high-luminosity LHC. Similar
sensitivity can also be achieved at a future 1 TeV 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
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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