950,044 research outputs found
Gauge-independent Renormalization of the N2HDM
The Next-to-Minimal 2-Higgs-Doublet Model (N2HDM) is an interesting benchmark
model for a Higgs sector consisting of two complex doublet and one real singlet
fields. Like the Next-to-Minimal Supersymmetric extension (NMSSM) it features
light Higgs bosons that could have escaped discovery due to their singlet
admixture. Thereby, the model allows for various different Higgs-to-Higgs decay
modes. Contrary to the NMSSM, however, the model is not subject to
supersymmetric relations restraining its allowed parameter space and its
phenomenology. For the correct determination of the allowed parameter space,
the correct interpretation of the LHC Higgs data and the possible distinction
of beyond-the-Standard Model Higgs sectors higher order corrections to the
Higgs boson observables are crucial. This requires not only their computation
but also the development of a suitable renormalization scheme. In this paper we
have worked out the renormalization of the complete N2HDM and provide a scheme
for the gauge-independent renormalization of the mixing angles. We discuss the
renormalization of the soft breaking parameter and
the singlet vacuum expectation value . Both enter the Higgs self-couplings
relevant for Higgs-to-Higgs decays. We apply our renormalization scheme to
different sample processes such as Higgs decays into bosons and decays into
a lighter Higgs pair. Our results show that the corrections may be sizeable and
have to be taken into account for reliable predictions
Intracluster Entropy from Joint X-ray and Sunyaev-Zel'dovich Observations
The temperature and density of the hot diffuse medium pervading galaxy groups and clusters combine into one significant quantity, the entropy. Here we express the entropy levels and profiles in model-independent forms by joining two observables, the X-ray luminosity and the change in the CMB intensity due to the Sunyaev-Zel'dovich (SZ) effect. Thus we present both global scaling relations for the entropy levels from clusters and groups, and a simple expression yielding the entropy profiles in individual clusters from resolved X-ray surface brightness and SZ spatial distributions. We propose that our approach provides two useful tools for comparing large data samples with models, in order to probe the processes that govern the thermal state of the hot intracluster medium. The feasibility of using such a diagnostic for the entropy is quantitatively assessed, based on current X-ray and upcoming SZ measurements
Learning solution of nonlinear constitutive material models using physics-informed neural networks: COMM-PINN
We applied physics-informed neural networks to solve the constitutive
relations for nonlinear, path-dependent material behavior. As a result, the
trained network not only satisfies all thermodynamic constraints but also
instantly provides information about the current material state (i.e., free
energy, stress, and the evolution of internal variables) under any given
loading scenario without requiring initial data. One advantage of this work is
that it bypasses the repetitive Newton iterations needed to solve nonlinear
equations in complex material models. Additionally, strategies are provided to
reduce the required order of derivation for obtaining the tangent operator. The
trained model can be directly used in any finite element package (or other
numerical methods) as a user-defined material model. However, challenges remain
in the proper definition of collocation points and in integrating several
non-equality constraints that become active or non-active simultaneously. We
tested this methodology on rate-independent processes such as the classical von
Mises plasticity model with a nonlinear hardening law, as well as local damage
models for interface cracking behavior with a nonlinear softening law. Finally,
we discuss the potential and remaining challenges for future developments of
this new approach
Intracluster Entropy from Joint X-ray and Sunyaev-Zel'dovich Observations
The temperature and density of the hot diffuse medium pervading galaxy groups
and clusters combine into one significant quantity, the entropy. Here we
express the entropy levels and profiles in model-independent forms by joining
two observables, the X-ray luminosity and the change in the CMB intensity due
to the Sunyaev-Zel'dovich (SZ) effect. Thus we present both global scaling
relations for the entropy levels from clusters and groups, and a simple
expression yielding the entropy profiles in individual clusters from resolved
X-ray surface brightness and SZ spatial distributions. We propose that our
approach provides two useful tools for comparing large data samples with
models, in order to probe the processes that govern the thermal state of the
hot intracluster medium. The feasibility of using such a diagnostic for the
entropy is quantitatively assessed, based on current X-ray and upcoming SZ
measurements.Comment: 9 pages, 2 figures, uses REVTeX4 + emulateapj.cls and apjfonts.sty.
Accepted by Ap
Z' signal from the LEP2 data
The many-parametric fit of the LEP2 data on e^+e^-\to e^+e^-, \mu^+\mu^-,
\tau^+\tau^- processes is performed to estimate signals of the Abelian Z'-boson
beyond the standard model. The model-independent relations between the Z'
couplings to the standard model particles allow to describe the Z' effects in
lepton processes by 4 independent parameters. No signal is found by the
complete LEP2 data set, and the 1.3\sigma signal is detected by the fit of the
backward bins. The Z' couplings to the vector and axial-vector lepton currents
are constrained. The comparisons with the one-parameter fits and with the LEP1
experiments are performed.Comment: 6 pages, 2 figures, RevTeX. The paper was completely rewritten. The
errors in the first version were eliminated. The comparison with the LEP1
data is adde
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