Korea Institute of Science and Technology Information

About: Korea Institute of Science and Technology Information is a facility organization based out in Daejeon, South Korea. It is known for research contribution in the topics: Gravitational wave & LIGO. The organization has 1152 authors who have published 2319 publications receiving 93849 citations. The organization is also known as: Korea Institute of Science and Technology Information & KISTI.

Diving below the Spin-down Limit: Constraints on Gravitational Waves from the Energetic Young Pulsar PSR J0537-6910

Abstract: We present a search for quasi-monochromatic gravitational-wave signals from the young, energetic X-ray pulsar PSR J0537−6910 using data from the second and third observing runs of LIGO and Virgo. The search is enabled by a contemporaneous timing ephemeris obtained using Neutron star Interior Composition Explorer (NICER) data. The NICER ephemeris has also been extended through 2020 October and includes three new glitches. PSR J0537−6910 has the largest spin-down luminosity of any pulsar and exhibits fRequent and strong glitches. Analyses of its long-term and interglitch braking indices provide intriguing evidence that its spin-down energy budget may include gravitational-wave emission from a time-varying mass quadrupole moment. Its 62 Hz rotation frequency also puts its possible gravitational-wave emission in the most sensitive band of the LIGO/Virgo detectors. Motivated by these considerations, we search for gravitational-wave emission at both once and twice the rotation frequency from PSR J0537−6910. We find no signal, however, and report upper limits. Assuming a rigidly rotating triaxial star, our constraints reach below the gravitational-wave spin-down limit for this star for the first time by more than a factor of 2 and limit gravitational waves from the l = m = 2 mode to account for less than 14% of the spin-down energy budget. The fiducial equatorial ellipticity is constrained to less than about 3 ×10−5, which is the third best constraint for any young pulsar.

Search for lepton-flavor-violating tau-lepton decays to ℓγ at Belle

Abstract: Charged lepton flavor violation is forbidden in the Standard Model but possible in several new physics scenarios. In many of these models, the radiative decays τ± → l±γ (l = e, μ) are predicted to have a sizeable probability, making them particularly interesting channels to search at various experiments. An updated search via τ± → l±γ using full data of the Belle experiment, corresponding to an integrated luminosity of 988 fb−1, is reported for charged lepton flavor violation. No significant excess over background predictions from the Standard Model is observed, and the upper limits on the branching fractions, $$ \mathcal{B} $$ (τ± → μ±γ) ≤ 4.2 × 10−8 and $$ \mathcal{B} $$ (τ± → e±γ) ≤ 5.6 × 10−8, are set at 90% confidence level.

W and Z boson production in p-Pb collisions at √sNN=5.02 TeV

Abstract: The W and Z boson production was measured via the muonic decay channel in proton-lead collisions at √ sNN = 5.02 TeV at the Large Hadron Collider with the ALICE detector. The measurement covers backward (−4.46 10 GeV/c are determined. The results are compared to theoretical calculations both with and without including the nuclear modification of the parton distribution functions. The W-boson production is also studied as a function of the collision centrality: the cross section of muons from W-boson decays is found to scale with the average number of binary nucleon-nucleon collisions within uncertainties.

4G LTE network access system and pricing model for IoT MVNOs: spreading smart tourism

Abstract: The aim of this study is to facilitate market access by Internet of things (IoT) mobile virtual network operators (MVNOs) (`M2V' hereinafter) for the purpose of providing the IoT services required to implement more advanced smart tourism in the tourism sector, which is heavily influenced not only by the Internet but also by information and communications technology (ICT) in the era of fourth generation (4G) long term evolution (LTE) networks. The study produced the following results. It established a 4G LTE network-based technological access system, which is commercially offered all over the world, and suggested business models featuring diverse interworking between network and system through M2V access to 4G LTE, as well as the resulting wholesale price calculation model according to bandwidth. Based on the research model, both the Korean government and governments of other countries can be expected to further advance smart tourism in the future by implementing policy and institutional supports that aim to enable 4G LTE network-based M2V to realize a technological access system, and by inducing M2V to make inroads into the tourism industry based on diversified business models.