73 research outputs found
Jet azimuthal angle correlations in the production of a Higgs boson pair plus two jets at hadron colliders
Azimuthal angle correlations of two jets in the process are
studied. The loop induced gluon fusion
(GF) sub-process and the weak boson fusion (WBF)
sub-process are considered. The GF sub-process exhibits strong correlations in
the azimuthal angles of the two jets measured from the
production plane of the Higgs boson pair and the difference between these two
angles , and a very small correlation in the sum of them
. The impact of using a finite top mass value on
the correlations is found crucial. The transverse momentum of the Higgs boson
can be used to enhance or suppress the correlations. The impact of a
non-standard value for the triple Higgs self-coupling on the correlations is
found much smaller than that on other observables, such as the invariant mass
of the two Higgs bosons. The peak shifts of the azimuthal angle distributions
reflect the magnitude of parity violation in the amplitude and the
dependence of the distributions on parity violating phases is analytically
clarified. The WBF sub-process also produces correlated distributions and it is
found that they are not induced by the quantum effect of the intermediate weak
bosons but mainly by a kinematic effect. This kinematic effect is a
characteristic feature of the WBF sub-process and is not observed in the GF
sub-process. It is found that the correlations are different in the GF and in
the WBF sub-processes. As part of the process dependent information, they will
be helpful in the analyses of both the GF sub-process and the WBF sub-process
at the LHC.Comment: 35 pages, 12 figures, 3 table
Fiducial polarization observables in hadronic WZ production: A next-to-leading order QCD+EW study
We present a study at next-to-leading-order (NLO) of the process , where , at the
Large Hadron Collider. We include the full NLO QCD corrections and the NLO
electroweak (EW) corrections in the double-pole approximation. We define eight
fiducial polarization coefficients directly constructed from the
polar-azimuthal angular distribution of the decay leptons. These coefficients
depend strongly on the kinematical cuts on the transverse momentum or rapidity
of the individual leptons. Similarly, fiducial polarization fractions are also
defined and they can be directly related to the fiducial coefficients. We
perform a detailed analysis of the NLO QCD+EW fiducial polarization observables
including theoretical uncertainties stemming from the scale variation and
parton distribution function uncertainties, using the fiducial phase space
defined by the ATLAS and CMS experiments. We provide results in the helicity
coordinate system and in the Collins-Soper coordinate system, at a
center-of-mass energy of 13 TeV. The EW corrections are found to be important
in two of the angular coefficients related to the boson, irrespective of
the kinematical cuts or the coordinate system. Meanwhile, those EW corrections
are very small for the bosons.Comment: Substantial improvement after useful comments from the anonymous
referee: Numerical results for the EW corrections to the cross sections and
distributions shifted by -5 (-2)% for ATLAS (CMS) cuts after fixing a bug in
the momentum assignment in some cut and histogram routines; results for
polarization observables marginally affected, hence conclusions for them
unchanged; published versio
Polarisation at NLO in WZ production at the LHC
The pair production of a and a boson at the LHC is an important
process to study the triple-gauge boson couplings as well as to probe new
physics that could arise in the gauge sector. In particular the leptonic
channel is considered by ATLAS and CMS
collaborations. Polarisation observables can help pinning down new physics and
give information on the spin of the gauge bosons. Measuring them requires high
statistics as well as precise theoretical predictions. We define in this
contribution fiducial polarisation observables for the and bosons and
we present theoretical predictions in the Standard Model at next-to-leading
order (NLO) including QCD as well as NLO electroweak corrections, the latter in
the double-pole approximation. We also show that this approximation works
remarkably well for production at the LHC by comparing to the full
results.Comment: 6 pages, 2 figures, 2 tables. Contribution to the proceedings of the
54th Rencontres de Moriond, EW interactions and unified theory, March 16-23
2019, La Thuile, Ital
Prospects for Higgs physics at energies up to 100 TeV
We summarise the prospects for Higgs boson physics at future proton-proton
colliders with centre of mass (c.m.) energies up to 100 TeV. We first provide
the production cross sections for the Higgs boson of the Standard Model from 13
TeV to 100 TeV, in the main production mechanisms and in subleading but
important ones such as double Higgs production, triple production and
associated production with two gauge bosons or with a single top quark. We then
discuss the production of Higgs particles in beyond the Standard Model
scenarios, starting with the one in the continuum of a pair of scalar,
fermionic and vector dark matter particles in Higgs-portal models in various
channels with virtual Higgs exchange. The cross sections for the production of
the heavier CP-even and CP-odd neutral Higgs states and the charged Higgs
states in two-Higgs doublet models, with a specific study of the case of the
Minimal Supersymmetric Standard Model, are then given. The sensitivity of a 100
TeV proton machine to probe the new Higgs states is discussed and compared to
that of the LHC with a c.m. energy of 14 TeV and at high luminosity.Comment: 61 pages, 16 figures, 6 tables; review article. v2: numbers and
figures updated, aknowledgments modified, references added and typos
corrected. Matches the published versio
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