408 research outputs found
Search for Narrow-Width ttbar Resonances in ppbar Collisions at center of mass energy = 1.8 TeV
We present a preliminary result on a search for narrow-width resonances that
decay into ttbar pairs using 130 pb^{-1} of lepton plus jets data in ppbar
collisions at center of mass energy = 1.8 TeV. No significant deviation from
Standard Model prediction is observed. 95% C.L. upper limits on the production
cross section of the narrow-width resonance times its branching fraction to
ttbar are presented for different resonance masses, M_X. We also exclude the
existence of a leptophobic topcolor particle, X, with M_X < 560 GeV/c^2 for a
width \Gamma_X = 0.012 M_X.Comment: 3 pages, 1 figure; Submitted for proceedings of 5th International
Conference on Quark Confinement and Hadron spectrum, held in Italy, from
11-14 Sep., 200
Brane-Production and the Neutrino-Nucleon cross section at Ultra High Energies in Low Scale Gravity Models
The origin of the ultra high energy cosmic ray (UHECR) showers has remained
as a mystery among particle physicists and astrophysicists. In low scale
gravity models, where the neutrino-nucleon cross section rises to typical
hadronic values at energies above eV, the neutrino becomes a
candidate for the primary that initiates these showers. We calculate the
neutrino-nucleon cross section at ultra high energies by assuming that it is
dominated by the production of p-branes. We show, using a generalized
Randall-Sundrum model, that the neutrino-nucleon cross-section at neutrino
energies of GeV is of the order of 100 mb, which is required for
explaining UHECR events. Similar result also follows in other models such as
the Lykken-Randall model.Comment: 13 pages, 2 figures, significantly revised version, no change in
conclusion
Comparative study of nifepidine and isoxsuprine in suppression of preterm labour
Background: A prospective study was conducted to compare the efficacy of nifedipine against isoxsuprine in preventing preterm labour and also to evaluate maternal side effects and neonatal outcome.Methods: This was a randomized prospective comparative study done at MGM hospital and research center, Patna, Bihar between 15/03/2014 to 15/02/2016. 75 antenatal women with gestational age between 28 to 36 weeks were selected who fulfilled the inclusion criteria for the study, were given nifedipine and were monitored throughout the course of treatment.Results: Groups were compared with mean prolongation of delivery, side effects, neonatal outcome, parity, cervical effacements. Nifedipine was twice more effective than isoxsuprine hydrochloride as a uterine tocolytic agent while side effects were comparable with fewer side effects in nifedipine group. Neonatal outcome was better with nifedipine in comparison to isoxsuprine.Conclusions: There is a high incidence of preterm labour in India. The present study found that nifedipine has better tocolytic efficacy, less side effects and better tolerability as compared to isoxsuprine.
Functionalized Carbon Nanotube and MnO2 Nanoflower Hybrid as an Electrode Material for Supercapacitor Application
Functionalized carbon nanotube (FCNT) and Manganese Oxide (MnO2) nanoflower hybrid material was synthesized using hydrothermal technique as a promising electrode material for supercapacitor applications. The morphological investigation revealed the formation of ‘nanoflower’ like structure of MnO2 connected with FCNT, thus paving an easy path for the conduction of electrons during the electrochemical mechanism. A significant improvement in capacitance properties was observed in the hybrid material, in which carbon nanotube acts as a conducting cylindrical path, while the major role of MnO2 was to store the charge, acting as an electrolyte reservoir leading to an overall improved electrochemical performance. The full cell electrochemical analysis of FCNT-MnO2 hybrid using 3 M potassium hydroxide (KOH) electrolyte indicated a specific capacitance of 359.53 F g−1, specific energy of 49.93 Wh kg−1 and maximum specific power of 898.84 W kg−1 at 5 mV s−1. The results show promise for the future of supercapacitor development based on hybrid electrode materials, where high specific energy can be achieved along with high specific power and long cycle life
Cross Sections for Leptophobic Topcolor Z' decaying to top-antitop
We present numerical calculations of the production cross section of a heavy
Z' resonance in hadron-hadron collisions with subsequent decay into top-antitop
pairs. In particular, we consider the leptophobic topcolor Z' discussed under
Model IV of hep-ph/9911288 which has predicted cross sections large enough to
be experimentally accessible at the Fermilab Tevatron and the Large Hadron
Collider at CERN. This article presents an updated calculation valid for the
Tevatron and all proposed LHC collision energies. Cross sections are presented
for various Z' widths, in p-pbar collisions at \sqrt{s}=2 TeV, and in p-p
collisions at \sqrt{s}=7, 8, 10 and 14 TeV.Comment: 6 pages, 5 figures (Submitted to PRD); The European Physical Journal
C, Volume 72, Issue
Reference priors for high energy physics
Bayesian inferences in high energy physics often use uniform prior
distributions for parameters about which little or no information is available
before data are collected. The resulting posterior distributions are therefore
sensitive to the choice of parametrization for the problem and may even be
improper if this choice is not carefully considered. Here we describe an
extensively tested methodology, known as reference analysis, which allows one
to construct parametrization-invariant priors that embody the notion of minimal
informativeness in a mathematically well-defined sense. We apply this
methodology to general cross section measurements and show that it yields
sensible results. A recent measurement of the single top quark cross section
illustrates the relevant techniques in a realistic situation
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