11,691 research outputs found
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
Determining the core radio luminosity function of radio AGNs via copula
The radio luminosity functions (RLFs) of active galactic nuclei (AGNs) are
traditionally measured based on total emission, which doesn't reflect the
current activity of the central black hole. The increasing interest in compact
radio cores of AGNs requires determination of the RLF based on core emission
(i.e., core RLF). In this work we have established a large sample (totaling
1207) of radio-loud AGNs, mainly consisting of radio galaxies (RGs) and
steep-spectrum radio quasars (SSRQs). Based on the sample, we explore the
relationship between core luminosity () and total luminosity () via a
powerful statistical tool called "Copula". The conditional probability
distribution is obtained. We derive the core
RLF as a convolution of with the total RLF
which was determined by previous work. We relate the separate RG and SSRQ core
RLFs via a relativistic beaming model and find that SSRQs have an average
Lorentz factor of , and that most are seen within
of the jet axis. Compared with
the total RLF which is mainly contributed by extended emission, the core RLF
shows a very weak luminosity-dependent evolution, with the number density
peaking around for all luminosities. Differences between core
and total RLFs can be explained in a framework involving a combination of
density and luminosity evolutions where the cores have significantly weaker
luminosity evolution than the extended emission.Comment: Accepted for publication in the ApJ
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