Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userKKMC-hh for Precision Electroweak Phenomenology at the LHC
147
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We describe the program KKMC-hh, which calculates Z boson processes in hadronic collisions using coherent exclusive exponentiation (CEEX) with exact second-order photonic corrections at next-to-leading log and first-order weak vertex corrections, including initial and final state photonic radiation and initial-final interference. We describe current applications to precision forward-backward asymmetry calculations for the measurement of the electroweak mixing angle at the LHC.
rate research
Read More
KKMC-hh is a hadronic event generator for Z boson production and decays, which includes exponentiated multi-photon radiation and first-order electroweak corrections. We have used KKMC-hh to investigate the role of initial sate radiation (ISR) and initial-final interference (IFI) in precision electroweak analyses at the LHC. We compare the effect of this radiation on angular distributions and forward-backward asymmetry, which are particularly important for the measurement of the weak mixing angle. We discuss the relation of the ISR implementation in KKMC-hh to ISR from parton distribution functions with QED corrections.
We explore the potential of the CERN Large Hadron Collider (LHC) to test the dynamical torsion parameters. The form of the torsion action can be established from the requirements of consistency of effective quantum field theory. The most phenomenologically relevant part of the torsion tensor is dual to a massive axial vector field. This axial vector has geometric nature, that means it does not belong to any representation of the gauge group of the SM extension or GUT theory. At the same time, torsion should interact with all fermions, that opens the way for the phenomenological applications. We demonstrate that LHC collider can establish unique constraints on the interactions between fermions and torsion field considerably exceeding present experimental lower bounds on the torsion couplings and its mass. It is also shown how possible non-universal nature of torsion couplings due to the renormalization group running between the Planck and TeV energy scales can be tested via the combined analysis of Drell-Yan and $tbar{t}$ production processes.
The future 100 TeV FCC-hh hadron collider will give access to rare but clean final states which are out of reach of the HL-LHC. One such process is the $Zh$ production channel in the $( ubar{ u} / ell^{+}ell^{-})gammagamma$ final states. We study the sensitivity of this channel to the $mathcal{O}_{varphi q}^{(1)}$, $mathcal{O}_{varphi q}^{(3)}$, $mathcal{O}_{varphi u}$, and $mathcal{O}_{varphi d}$ SMEFT operators, which parametrize deviations of the $W$ and $Z$ couplings to quarks, or, equivalently, anomalous trilinear gauge couplings (aTGC). While our analysis shows that good sensitivity is only achievable for $mathcal{O}_{varphi q}^{(3)}$, we demonstrate that binning in the $Zh$ rapidity has the potential to improve the reach on $mathcal{O}_{varphi q}^{(1)}$. Our estimated bounds are one order of magnitude better than projections at HL-LHC and is better than global fits at future lepton colliders. The sensitivity to $mathcal{O}_{varphi q}^{(3)}$ is competitive with other channels that could probe the same operator at FCC-hh. Therefore, combining the different diboson channels sizeably improves the bound on $mathcal{O}_{varphi q}^{(3)}$, reaching a precision of $|delta g_{1z}| lesssim 2 times 10^{-4}$ on the deviations in the $ZWW$ interactions.
The prospects for electroweak measurements at the Large Hadron Collider (LHC) are discussed. In addition to high-luminosity results, special emphasis is placed on early start-up measurements with a total luminosity ranging from 10/pb to 100/pb, using the general-purpose detectors ATLAS and CMS and their initially larger calibration and alignment uncertainties. Topics discussed here include inclusive W and Z production, W-boson mass, Z forward-backward asymmetry, Z-plus-jets production and di-boson production, the latter constraining trilinear electroweak gauge couplings. (Invited talk at the 34th ICHEP, Philadelphia, USA, July/August 2008)
We study the LHC constraints on an $R$-symmetric SUSY model, where the neutrino masses are generated through higher dimensional operators involving the pseudo-Dirac bino, named bi$ u$o. We consider a particle spectrum where the squarks are heavier than the lightest neutralino, which is a pure bi$ u$o. The bi$ u$o is produced through squark decays and it subsequently decays to a combination of jets and leptons, with or without missing energy, via its mixing with the Standard Model neutrinos. We recast the most recent LHC searches for jets+missing energy with $sqrt{s}=13~$TeV and $mathcal{L}=36~{rm fb}^{-1}$ of data to determine the constraints on the squark and bi$ u$o masses in this model. We find that squarks as light as 350~GeV are allowed if the bi$ u$o is lighter than 150~GeV and squarks heavier than 950~GeV are allowed for any bi$ u$o mass. We also present forecasts for the LHC with $sqrt{s}=13$~TeV and $mathcal{L}=300~{rm fb}^{-1}$ and show that squarks up to 1150~GeV can be probed.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
