15,522 research outputs found
All-derivable points in nest algebras
Suppose that is an operator algebra on a Hilbert space . An
element in is called an all-derivable point of
for the strong operator topology if every strong operator topology continuous
derivable mapping at is a derivation. Let be a
complete nest on a complex and separable Hilbert space . Suppose that
belongs to with and write for
or . Our main result is: for any with
, if is invertible in
, then is an all-derivable point in
for the strong operator topology.Comment: 12 pages, late
Diphoton excess at 750 GeV: gluon-gluon fusion or quark-antiquark annihilation?
Recently, ATLAS and CMS collaboration reported an excess in the diphoton
events, which can be explained by a new resonance with mass around 750 GeV. In
this work, we explored the possibility of identifying if the hypothetical new
resonance is produced through gluon-gluon fusion or quark-antiquark
annihilation, or tagging the beam. Three different observables for beam
tagging, namely the rapidity and transverse momentum distribution of the
diphoton, and one tagged bottom-jet cross section, are proposed. Combining the
information gained from these observables, a clear distinction of the
production mechanism for the diphoton resonance is promising.Comment: 20 pages, 7 figure
Next-to-leading order QCD corrections to the single top quark production via model-independent t-q-g flavor-changing neutral-current couplings at hadron colliders
We present the calculations of the complete next-to-leading order (NLO) QCD
effects on the single top productions induced by model-independent
flavor-changing neutral-current couplings at hadron colliders. Our results show
that, for the coupling the NLO QCD corrections can enhance the total
cross sections by about 60% and 30%, and for the coupling by about 50%
and 20% at the Tevatron and LHC, respectively, which means that the NLO
corrections can increase the experimental sensitivity to the FCNC couplings by
about 10%30%. Moreover, the NLO corrections reduce the dependence of the
total cross sections on the renormalization or factorization scale
significantly, which lead to increased confidence on the theoretical
predictions. Besides, we also evaluate the NLO corrections to several important
kinematic distributions, and find that for most of them the NLO corrections are
almost the same and do not change the shape of the distributions.Comment: minor changes, version published in PR
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