284 research outputs found
Same-sign trileptons and four-leptons as signatures of new physics at the Large Hadron Collider
We point out that same-sign multilepton events, not given due attention yet
for new physics search, can be extremely useful at the Large Hadron Collider.
After showing the easy reducibility of the standard model backgrounds, we
demonstrate the viability of same-sign trilepton signals for R-parity breaking
supersymmetry, at both 7 and 14 TeV. We find that same-sign four-leptons, too,
can have appreciable rates. Same-sign trileptons are also expected, for
example, in Little Higgs theories with T-parity broken by anomaly terms.Comment: 5 pages, 1 figure; v2: minor additions to text, references added,
version to appear in Physical Review D (Rapid Communications
Gauge coupling unification with large extra dimensions
We make a detailed study of the unification of gauge couplings in the MSSM
with large extra dimensions. We find some scenarios where unification can be
achieved (with the strong coupling constant at the Z mass within one standard
deviation of the experimental value) with both the compactification scale and
the SUSY breaking scale in the few TeV range. No enlargement of the gauge group
or particle content is needed. One particularly interesting scenario is when
the SUSY breaking scale is larger than the compactification scale, but both are
small enough to be probed at the CERN LHC. Unification in two scales scenarios
is also investigated and found to give results within the LHC.Comment: 17 pages, 3 figures, some discussions added, few additional
references included. Version to appear in Phys. Rev.
Discrimination of low missing energy look-alikes at the LHC
The problem of discriminating possible scenarios of TeV scale new physics
with large missing energy signature at the Large Hadron Collider (LHC) has
received some attention in the recent past. We consider the complementary, and
yet unexplored, case of theories predicting much softer missing energy spectra.
As there is enough scope for such models to fake each other by having similar
final states at the LHC, we have outlined a systematic method based on a
combination of different kinematic features which can be used to distinguish
among different possibilities. These features often trace back to the
underlying mass spectrum and the spins of the new particles present in these
models. As examples of "low missing energy look-alikes", we consider
Supersymmetry with R-parity violation, Universal Extra Dimensions with both
KK-parity conserved and KK-parity violated and the Littlest Higgs model with
T-parity violated by the Wess-Zumino-Witten anomaly term. Through detailed
Monte Carlo analysis of the four and higher lepton final states predicted by
these models, we show that the models in their minimal forms may be
distinguished at the LHC, while non-minimal variations can always leave scope
for further confusion. We find that, for strongly interacting new particle
mass-scale ~600 GeV (1 TeV), the simplest versions of the different theories
can be discriminated at the LHC running at sqrt{s}=14 TeV within an integrated
luminosity of 5 (30) fb^{-1}.Comment: 40 pages, 10 figures; v2: Further discussions, analysis and one
figure added, ordering of certain sections changed, minor modifications in
the abstract, version as published in JHE
Early Advanced LIGO binary neutron-star sky localization and parameter estimation
2015 will see the first observations of Advanced LIGO and the start of the gravitational-wave (GW) advanced-detector era. One of the most promising sources for ground- based GW detectors are binary neutron-star (BNS) coalescences. In order to use any detections for astrophysics, we must understand the capabilities of our parameter-estimation analysis. By simulating the GWs from an astrophysically motivated population of BNSs, we examine the accuracy of parameter inferences in the early advanced-detector era. We find that sky location, which is important for electromagnetic follow-up, can be determined rapidly (~ 5 s), but that sky areas may be hundreds of square degrees. The degeneracy between component mass and spin means there is significant uncertainty for measurements of the individual masses and spins; however, the chirp mass is well measured (typically better than 0.1%)
EFFECT OF LCC AND SPAD BASED NITROGEN MANAGEMENT ON GROWTH AND YIELD OF LOWLAND RICE (ORYZA SATIVA L.)
A field experiment was conducted at Raichur during kharif-2009 to validate the effect of Leaf Colour Chart (LCC) and Soil and Plant Analysis Development meter (SPAD) based nitrogen (N) management on growth and yield of lowland rice (Oryza sativa L.). Treatments consists of N application based on LCC thresholds (3.5 to 5.0) and SPAD values (30 to 40) compared with state recommendation and farmers’ practice (220 kg ha-1), were imposed through RCBD replicating thrice. The results revealed that N application based on LCC values @ 5 (120 kg ha-1) and SPAD @ 37.5 (120 kg ha-1) were more beneficial in enhancing the growth and yield of the low land rice. The split application of N at higher doses enhances its uptake over basal application. Significantly better growth parameters were recorded when N requirement for rice was applied based on LCC @ 5 (120 kg ha-1)) and SPAD @ 37.5 (120 kg ha-1). These were also recorded better yield parameters over farmers’ method and low N rates treatments. The results of the study implied that LCC threshold @ 5.0 or SPAD @ 37.5 are found to be effective as a decision tool for optimum N application in rice
Testing gravitational-wave searches with numerical relativity waveforms: Results from the first Numerical INJection Analysis (NINJA) project
The Numerical INJection Analysis (NINJA) project is a collaborative effort
between members of the numerical relativity and gravitational-wave data
analysis communities. The purpose of NINJA is to study the sensitivity of
existing gravitational-wave search algorithms using numerically generated
waveforms and to foster closer collaboration between the numerical relativity
and data analysis communities. We describe the results of the first NINJA
analysis which focused on gravitational waveforms from binary black hole
coalescence. Ten numerical relativity groups contributed numerical data which
were used to generate a set of gravitational-wave signals. These signals were
injected into a simulated data set, designed to mimic the response of the
Initial LIGO and Virgo gravitational-wave detectors. Nine groups analysed this
data using search and parameter-estimation pipelines. Matched filter
algorithms, un-modelled-burst searches and Bayesian parameter-estimation and
model-selection algorithms were applied to the data. We report the efficiency
of these search methods in detecting the numerical waveforms and measuring
their parameters. We describe preliminary comparisons between the different
search methods and suggest improvements for future NINJA analyses.Comment: 56 pages, 25 figures; various clarifications; accepted to CQ
Search for High-energy Neutrinos from Binary Neutron Star Merger GW170817 with ANTARES, IceCube, and the Pierre Auger Observatory
The Advanced LIGO and Advanced Virgo observatories recently discovered gravitational waves from a binary neutron star inspiral. A short gamma-ray burst (GRB) that followed the merger of this binary was also recorded by the Fermi Gamma-ray Burst Monitor (Fermi-GBM), and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), indicating particle acceleration by the source. The precise location of the event was determined by optical detections of emission following the merger. We searched for high-energy neutrinos from the merger in the GeV-EeV energy range using the Antares, IceCube, and Pierre Auger Observatories. No neutrinos directionally coincident with the source were detected within ± 500 s around the merger time. Additionally, no MeV neutrino burst signal was detected coincident with the merger. We further carried out an extended search in the direction of the source for high-energy neutrinos within the 14 day period following the merger, but found no evidence of emission. We used these results to probe dissipation mechanisms in relativistic outflows driven by the binary neutron star merger. The non-detection is consistent with model predictions of short GRBs observed at a large off-axis angle
Cytotoxicity effect and antioxidant potential of 5-Hydroxymethyl Furfural (5-HMF) analogues-An advance approach
Rivea hypocrateriformis (Desr.) Choisy is a profound medicinal belongs to the family Convolvulaceae. Natural products are considered as an alternative source for a positive approach to the drug design and drug discovery. R. hypocrateriformis is becoming the most important natural source to produce diverse phytometabolites with varying biochemical activities. Therefore, in the proposed study, we utilizing R. hypocrateriformis for isolating the 5-hydroxymethyl-2-furfural (5-HMF) and characterized it by different scientifically approved spectroscopic techniques namely 1HNMR, 13C NMR, FTIR and mass spectroscopy respectively. As a part of this study, the synthesis of chemical analogues has been achieved by coupling 5-HMF with quinoline derivatives and it was also studied for their antioxidant and anticancer potentials. The results demonstrated that amongst the test compounds, 3d and 3b have shown significant free radical scavenging assay followed by 3e and 3a with a maximum inhibitory effect, 76.69 %, 75.90 %, 67.60 % and 56.07 % respectively at 50 μg/mL. The anticancer activity studied through SRB assay showed that, compound 3a was effective at low concentration (10 μg/mL) against the Colo-205 cell line. This study demonstrated the applicability of R. hypocrateriformis against the cytotoxicity and antioxidant potential of 5-HMF. It can further be utilized by the researcher and pharmaceutical industry to design a potential drug candidate to treat cellular toxicity
Ethyl 4-(4′-heptanoyloxyphenyl)-6-methyl-3,4-dihydropyrimidin-2-one-5-carboxylate Prevents Progression of Monocrotaline-induced Pulmonary Arterial Hypertension in Rats
Therapies to prevent onset and progression of pulmonary arterial pressure are not very effective yet. This study was designed to investigate the effects of a novel dihydropyrimidinone, ethyl 4-(4′-heptanoyloxyphenyl)-6-methyl-3,4-dihydropyrimidin-2-one-5-carboxylate (H-DHPM) on pathogenesis of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). For the same purpose, rats were injected intraperitoneally (i.p.) a single dose (60 mg/kg) of MCT which led to development of PAH in 21 days. MCT insult caused high mortality, pulmonary vascular and parenchymal remodelling. Since the course of PAH pathogenesis is characterised by an early onset and progression phases, H-DHPM was administered i.p. at 30 mg/kg dosage in MCT pre-injected animals either from day 0 through day 21 or day 14 though day 21 of MCT injection in two separate treatment groups. H-DHPM significantly improved survival, prevented remodelling of pulmonary vasculature and parenchyma and subsequently ameliorated PAH pathogenesis. Moreover, we observed significant decrease in right ventricle hypertrophy, measured by wet weight of right ventricle (RV) divided by wet weight of left ventricle plus septum (LV+S), in H-DHPM treated groups as compared to MCT injected animals. These findings suggest H-DHPM not only prevented development of PAH but also treated the PAH pathogenesis in progressive phase. In conclusion, our data determines H-DHPM, might be a future drug for the prevention of PAH
Size-controlled synthesis of monodispersed gold nanoparticles via carbon monoxide gas reduction
An in depth analysis of gold nanoparticle (AuNP) synthesis and size tuning, utilizing carbon monoxide (CO) gas as a reducing agent, is presented for the first time. The sizes of the AuNPs are tunable from ~4 to 100 nm by altering the concentration of HAuCl4 and inlet CO gas-injection flow rate. It is also found that speciation of aqueous HAuCl4, prior to reduction, influences the size, morphology, and properties of AuNPs when reduced with CO gas. Ensemble extinction spectra and TEM images provide clear evidence that CO reduction offers a high level of monodispersity with standard deviations as low as 3%. Upon synthesis, no excess reducing agent remains in solution eliminating the need for purification. The time necessary to synthesize AuNPs, using CO, is less than 2 min
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