15,347 research outputs found
Discovery potential of Higgs boson pair production through 4+ final states at a 100 TeV collider
We explore the discovery potential of Higgs pair production at a 100 TeV
collider via full leptonic mode. The same mode can be explored at the LHC when
Higgs pair production is enhanced by new physics. We examine two types of fully
leptonic final states and propose a partial reconstruction method. The
reconstruction method can reconstruct some kinematic observables. It is found
that the variable determined by this reconstruction method and the
reconstructed visible Higgs mass are important and crucial to discriminate the
signal and background events. It is also noticed that a new variable, denoted
as which is defined as the mass difference of two possible
combinations, is very useful as a discriminant. We also investigate the
interplay between the direct measurements of couplings and other
related couplings and trilinear Higgs coupling at hadron colliders and
electron-positron colliders
Efficient Numerical Evaluation of Feynman Integral
Feynman loop integrals are a key ingredient for the calculation of higher
order radiation effects, and are responsible for reliable and accurate
theoretical prediction. We improve the efficiency of numerical integration in
sector decomposition by implementing a quasi-Monte Carlo method associated with
the CUDA/GPU technique. For demonstration we present the results of several
Feynman integrals up to two loops in both Euclidean and physical kinematic
regions in comparison with those obtained from FIESTA3. It is shown that both
planar and non-planar two-loop master integrals in the physical kinematic
region can be evaluated in less than half a minute with
accuracy, which makes the direct numerical approach viable for precise
investigation of higher order effects in multi-loop processes, e.g. the
next-to-leading order QCD effect in Higgs pair production via gluon fusion with
a finite top quark mass.Comment: 8 pages, 5 figures, published in Chinese Physics
Higgs Pair Production: Improved Description by Matrix Element Matching
Higgs pair production is crucial for measuring the Higgs boson self-coupling.
The dominant channel at hadron colliders is gluon fusion via heavy-quark loops.
We present the results of a fully exclusive simulation of gluon fusion Higgs
pair production based on the matrix elements for hh + 0, 1 partons including
full heavy-quark loop dependence, matched to a parton shower. We examine and
validate this new description by comparing it with (a) Higgs Effective Theory
predictions, (b) exact hh + 0-parton sample showered by pythia, and (c) exact
hh+1-parton distributions, by looking at the most relevant kinematic
distributions, such as PTh, PThh, Mhh spectra, and jet rate as well. We find
that matched samples provide an state-of-the-art accurate exclusive description
of the final state. The relevant LHE files for Higgs pair productions at the
LHC can be accessed via http://hepfarm02.phy.pku.edu.cn/foswiki/CMS/HH, which
can be used for relevant experimental analysis.Comment: accepted version in Phys. Rev. D. arXiv admin note: substantial text
overlap with arXiv:1110.172
Using LISA-like Gravitational Wave Detectors to Search for Primordial Black Holes
Primordial black hole (PBH), which can be naturally produced in the early
universe, remains a promising dark matter candidate . It can merge with a
supermassive black hole (SMBH) in the center of a galaxy and generate
gravitational wave (GW) signals in the favored frequency region of LISA-like
experiments. In this work, we initiate the study on the event rate calculation
for such extreme mass ratio inspirals (EMRI). Including the sensitivities of
various proposed GW detectors, we find that such experiments offer a novel and
outstanding tool to test the scenario where PBH constitutes (fraction of) dark
matter. The PBH energy density fraction of DM () could
potentially be explored as small as . Further, LISA has
the capability to search for PBH mass upto .
Other proposed GW experiments can probe lower PBH mass regime.Comment: 8 pages, 2 figure
- …