A
bstract
We classify shapes of Higgs boson pair invariant mass distributions
m
hh
, calculated at NLO with full top quark mass dependence, and visualise how distinct classes of shapes relate to the ...underlying coupling parameter space. Our study is based on a five-dimensional parameter space relevant for Higgs boson pair production in a non-linear Effective Field Theory framework. We use two approaches: an analysis based on predefined shape types and a classification into shape clusters based on unsupervised learning. We find that our method based on unsupervised learning is able to capture shape features very well and therefore allows a more detailed study of the impact of anomalous couplings on the
m
hh
shape compared to more conventional approaches to a shape analysis.
A
bstract
We present a calculation of the NLO QCD corrections to Higgs boson pair production within the framework of a non-linearly realised Effective Field Theory in the Higgs sector, described by ...the electroweak chiral Lagrangian. We analyse how the NLO corrections affect distributions in the Higgs boson pair invariant mass and the transverse momentum of one of the Higgs bosons. We find that these corrections lead to significant and non-homogeneous K-factors in certain regions of the parameter space. We also provide an analytical parametrisation for the total cross-section and the
m
hh
distribution as a function of the anomalous Higgs couplings that includes NLO corrections. Such a parametrisation can be useful for phenomenological studies.
We present a calculation of the NLO QCD corrections to Higgs boson pair production within the framework of a non-linearly realised Effective Field Theory in the Higgs sector, described by the ...electroweak chiral Lagrangian. We analyse how the NLO corrections affect distributions in the Higgs boson pair invariant mass and the transverse momentum of one of the Higgs bosons. We find that these corrections lead to significant and non-homogeneous K-factors in certain regions of the parameter space. We also provide an analytical parametrisation for the total cross-section and the mhh distribution as a function of the anomalous Higgs couplings that includes NLO corrections. Such a parametrisation can be useful for phenomenological studies.
Fullerene molecules absorbed on the highly anisotropic Au(110)-p(1x2) surface induce an ordered p(6x5) superstructure that has been solved by applying the 2D "direct methods" difference sum function ...to the surface x-ray diffraction data set. We found that the C (60)-gold interface is structurally much more complex than the one previously suggested by scanning tunneling microscopy data J. K. Gimzewski, S. Modesti, and R. R. Schlittler, Phys. Rev. Lett. 72, 1036 (1994). Indeed a large fraction of Au surface atoms are displaced from their original positions producing microscopic pits that may accommodate the fullerene molecules.
C
60 was deposited on Ni(110), Pt(111) and Ag(111) and annealed at different temperatures. The structural properties of the overlayer were investigated by low-energy electron diffraction, the changes ...induced by adsorption on its electronic properties were studied by valence band and core-level photoemission spectroscopy and inverse photoemission spectroscopy. On all surfaces C
60 is chemisorbed and a clear signature for charge transfer is found for C
60 on Ni(110) and Ag(111). Decomposition of C
60 takes place on Ni(110) and Pt(111) above 690
K and 560
K respectively. The decomposition is a kinetically limited reaction on both surfaces and on Pt(111) we find a very strongly chemisorbed precursor state for decomposition.
We report the first results obtained from the high energy resolution beam line at the storage ring ELETTRA of Trieste. The beam line has been designed to perform photoemission experiments in the ...vacuum ultraviolet (VUV) and soft X-ray (SXR) energy range. The radiation source is an undulator which consists of three sections, with 36 periods and a period length of 12.5 cm. It allows scanning of an energy range 17–900 eV using the 1st, 3rd and 5th harmonics. The monochromator is a spherical grating type and the resolving power at 400 eV, estimated from the K-shell photoabsorption of the N
2 molecule is well above 10 000. The spectra are better than any other spectra taken while operating with high flux, i.e. first order diffraction and grating not masked. Measurements taken at the oxygen and neon K-edges, the argon L
23 edges and of the helium double ionization spectra, indicate that the resolution is excellent from 65 to 870 eV.
PDF
