46 research outputs found
Search for excited spin-3/2 neutrinos at LHeC
We study the potential of the next collider, namely LHeC, with two
options TeV TeV, to search for excited spin-1/2
and spin-3/2 neutrinos. We calculate the single production cross section of
excited spin-1/2 and spin-3/2 neutrinos according to their effective currents
describing their interactions between gauge bosons and SM leptons. We choose
the decay mode of excited neutrinos and
decay mode of -boson for the analysis. We put some
kinematical cuts for the final state detectable particles and plot the
invariant mass distributions for signal and the corresponding backgrounds. In
order to obtain accessible limits for excited neutrino couplings, we show the
and contour plots for excited spin-1/2 and
excited spin-3/2 neutrinos, respectively.Comment: 15 pages, 8 figures, 5 Table
Search for couplings at the LHC
New physics models predict the possibility of extra neutral gauge bosons
() associated with an extra gauge symmetry. We study the couplings
of the Higgs boson to the boson and boson predicted by the new physics
models. The couplings of the boson to quarks can also be investigated
through the interactions. The accessible ranges of the parameter
space have been searched for processes and at the LHC with TeV.Comment: 10 pages, 10 figure
Anomalous couplings with beam polarization at the Compact Linear Collider
We study the anomalous couplings at the Compact Linear Collider
through the processes , and is the Weizsacker-Williams
photon). We give the 95\% confidence level limits for unpolarized and polarized
electron (positron) beam on the anomalous couplings for various values of the
integrated luminosities and center-of-mass energies. We show that the obtained
limits on the anomalous couplings through these processes can highly improve
the current experimental limits. In addition, our limits with beam polarization
are approximately two times better than the unpolarized case.Comment: Tables and references adde
Effects of the FCNC Couplings in Production of New Heavy Quarks within Z
We study the flavor changing neutral current couplings of new heavy quarks through the Z′ models at the LHC. We calculate the cross sections for the signal and the corresponding standard model background processes. Considering the present limits on the mass of new heavy quarks and the Z′ boson, we performed an analysis to investigate the parameter space (mixing and mass) through different Z′ models. For FCNC mixing parameter x=0.1 and the Z′ mass MZ′=2000 GeV and new heavy quark mass mt′=700 GeV at the LHC with s=13 TeV, we find the cross section for single production of new heavy quarks associated with top quarks as 5.8 fb, 3.3 fb, 1.5 fb, and 1.2 fb within the Zη′, Zψ′, ZLP′, and Zχ′ models, respectively. It is shown that the sensitivity would benefit from the flavor tagging
Pair Production of Fourth Family Charged Sleptons at Colliders
We study the pair production of , which is the supersymmetric
partner of the fourth family charged lepton, at the colliders. It
is shown that the investigation of this process at ILC/CLIC will give
opportunity to differentiate the MSSM with three and four families.Comment: 6 pages, 2 figure
Dimension-6 operator analysis of the CLIC sensitivity to new physics
We estimate the possible accuracies of measurements at the proposed CLICe+ e− collider of Higgs and W+W− production at centre-of-mass energies up to 3 TeV,
incorporating also Higgsstrahlung projections at higher energies that had not been considered previously, and use them to explore the prospective CLIC sensitivities to decoupled new physics. We present the resulting constraints on the Wilson coefficients of dimension6 operators in a model-independent approach based on the Standard Model effective field theory (SM EFT). The higher centre-of-mass energy of CLIC, compared to other projects such as the ILC and CEPC, gives it greater sensitivity to the coefficients of some of the operators we study. We find that CLIC Higgs measurements may be sensitive to new physics scales Λ = O(10) TeV for individual operators, reduced to O(1) TeV sensitivity for a global fit marginalising over the coefficients of all contributing operators. We give some examples
of the corresponding prospective constraints on specific scenarios for physics beyond the SM, including stop quarks and the dilaton/radion
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HE-LHC: The High-Energy Large Hadron Collider: Future Circular Collider Conceptual Design Report Volume 4
Abstract: In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100 TeV. Its unprecedented centre-of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries
HE-LHC: The High-Energy Large Hadron Collider – Future Circular Collider Conceptual Design Report Volume 4
In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100 TeV. Its unprecedented centre-of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries