1,718 research outputs found
Conversion of neutron stars to strange stars as the central engine of gamma-ray bursts
We study the conversion of a neutron star to a strange star as a possible
energy source for gamma-ray bursts. We use different recent models for the
equation of state of neutron star matter and strange quark matter. We show that
the total amount of energy liberated in the conversion is in the range of (1-4)
10^{53} ergs (one order of magnitude larger than previous estimates) and is in
agreement with the energy required to power gamma-ray burst sources at
cosmological distances.Comment: ApJ, 530, 2000 February 20, Lxxx (in press
Studi Deformasi Waduk Pendidikan Diponegoro Tahun 2016
According to SNI No. 1731-1989 dam is any artificial barrier, urugan type or any other type that can hold or store water both natural and artificial. In addition to benefits are very much dams also have a high risk because has the potential danger of collapse that could result in the loss of life and material losses, therefore it needs to be observed deformation to determine the condition of the dam.In this research will be observation of the deformation of Pendidikan Diponegoro dam, with GPS (Global Positioning System) observation methods will be observed of 9 monitoring points deformation (bench mark) spread around the body of the dam, the GPS observed data will be processing using scientific software GAMIT 10.6, deformation monitoring points were also observed changes in distance and height from the control points are placed outside the body of the dam, deformation observations carried out from April to June 2016, with twice the period of observation.The results of GPS observations during the observation period showed deformation monitoring points change the coordinate value with ranging from 0.06 cm to 1.4 cm for the X axis, 0.03 cm to 1.9 cm for the Y axis, and 0.4 cm to 1.3 cm for the Z axis. Distance and height changes based on total station and waterpass measurement during the observation period ranging from 0.09 mm to 1.7 mm and 0.15 mm to 1.8 mm. From the result of the dam deformation observation by GPS observation methods, total station, and waterpass shows deformation of the deformation monitoring points during the observation period, but based on the statistical test with 95% confidence level showed that there is no deformation of all the deformation monitoring points
Higgs boson pair production in gluon fusion at NLO with full top-quark mass dependence
We present the calculation of the cross section and invariant mass
distribution for Higgs boson pair production in gluon fusion at next-to-leading
order (NLO) in QCD. Top-quark masses are fully taken into account throughout
the calculation. The virtual two-loop amplitude has been generated using an
extension of the program GoSam supplemented with an interface to Reduze for the
integral reduction. The occurring integrals have been calculated numerically
using the program SecDec. Our results, including the full top-quark mass
dependence for the first time, allow us to assess the validity of various
approximations proposed in the literature, which we also recalculate. We find
substantial deviations between the NLO result and the different approximations,
which emphasizes the importance of including the full top-quark mass dependence
at NLO.Comment: Version published in PRL, v2: results at 13 TeV (v1 was at 14 TeV),
minor correction to virtual part included, conclusions unchange
Quark matter in compact stars: astrophysical implications and possible signatures
After a brief non technical introduction of the basic properties of strange
quark matter (SQM) in compact stars, we consider some of the late important
advances in the field, and discuss some recent astrophysical observational data
that could shed new light on the possible presence of SQM in compact stars. We
show that above a threshold value of the gravitational mass a neutron star
(pure hadronic star) is metastable to the decay (conversion) to an hybrid
neutron star or to a strange star. We explore the consequences of the
metastability of "massive" neutron stars and of the existence of stable compact
"quark" stars (hybrid neutron stars or strange stars) on the concept of
limiting mass of compact stars, and we give an extension of this concept with
respect to the "classical" one given in 1939 by Oppenheimer and Volkoff.Comment: Invited talk at "the Eleventh Marcel Grossman Meeting on General
Relativity", Berlin 200
Resummation of High Order Corrections in Boson Plus Jet Production at the LHC
We study the multiple soft gluon radiation effects in boson plus jet
production at the LHC. By applying the transverse momentum dependent
factorization formalism, the large logarithms introduced by the small total
transverse momentum of the boson plus jet final state system, are resummed
to all orders in the expansion of the strong interaction coupling at the
accuracy of Next-to-Leading Logarithm(NLL). We also compare the prediction of
our resummation calculation to the CMS data by employing a reweighting
procedure to estimate the effect from imposing kinematic cuts on the leptons
from boson decay, and find good agreement for both the imbalance transverse
momentum and the azimuthal angle correlation of the final state boson and
jet system, for production at the LHC.Comment: 7 pages, published versio
Media Impact on NFL Fans
The purpose of the study was to examine the complex relationship between NFL fans and the media in reaction to a newly hired NFL coach. The conclusions and process were important to all three groups because each group is directly affected by the others and the results. Fans can change the way they consume media and the organizations can change the way they interact with the media in an attempt to change the way the media writes about the team. It was known that media framing exists but the extent to which it exists in NFL circles had not been examined
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