Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userA spin on same-sign W-boson pair production
96
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We demonstrate that the LHC will be sensitive to quantum correlations between two quarks inside the proton. Same-sign W-boson pair production is the most promising channel for clear measurements of double parton scattering. The left-handed nature of the coupling between quarks and W-bosons makes it a prime probe to measure parton spin correlations. We perform a detailed analysis of double parton scattering, including relevant backgrounds. The analysis reveals that measurements comparing the rate at which two muons from W boson decays are produced in the same compared to opposite hemispheres are especially sensitive to spin correlations between two quarks inside the proton. We provide estimates of the significance of the measurements as a function of the integrated luminosity.
rate research
Read More
The future runs of LHC offer a unique opportunity to measure correlations between two partons inside the proton, which have never been experimentally detected. The process of interest is the production of two positively charged W-bosons decaying in the muon channel. We present a detailed analysis of proton-proton collisions at $sqrt{s}$ = 13 TeV, where we combine Monte Carlo event generators with our calculations of parton correlations. We carefully compare double parton scattering to relevant background processes and trace a path towards a clean signal sample. Several observables are constructed to demonstrate the effect of parton correlations with respect to clear benchmark values for uncorrelated scatterings. We find that especially spin correlations can be responsible for large effects in the variables we study, because of their direct relation with the parton angular momentum and, therefore, the directions of the muon momenta. We estimate the significance of the measurements as a function of the integrated luminosity and conclude that the LHC has the potential to detect, or put strong limits on, parton correlations in the near future.
We describe the calculation of the QCD contribution to same-sign $W$-pair production, $ppto e^pm u_e mu^pm u_mu jj$, resumming all contributions scaling as $alpha_W^4 alpha_s^{2+k}log^k(hat s/p_perp^2)$ [arXiv:2107.06818]. These leading logarithmic contributions are enhanced by typical cuts used for Vector Boson Scattering (VBS) studies. We show that while the cross sections are little affected by these corrections, other more exclusive observables relevant for experimental studies are affected more significantly.
We present the results of the first calculation of the logarithmic corrections to the QCD contribution to same-sign $W$-pair production, $ppto e^pm u_e mu^pm u_mu jj$, for same-sign charged leptons. This includes all leading logarithmic contributions which scale as $alpha_W^4 alpha_s^{2+k}log^k(hat s/p_perp^2)$. This process is important for the study of electroweak couplings and hence the QCD contributions are usually suppressed through a choice of Vector Boson Scattering (VBS) cuts. These select regions of phase space where logarithms in $hat s/p_perp^2$ are enhanced. While the logarithmic corrections lead to a small change for the cross sections, several distributions relevant for experimental studies are affected more significantly.
$W$ boson pair production processes at $e^+e^-$ and $pp$ colliders have been conventionally interpreted as measurements of $WWZ$ and $WWgamma$ triple gauge couplings (TGCs). Such interpretation is based on the assumption that new physics effects other than anomalous TGCs are negligible. While this TGC dominance assumption was well-motivated and useful at LEP2 thanks to precision electroweak constraints, it is already challenged by recent LHC data. In fact, contributions from anomalous $Z$ boson couplings that are allowed by electroweak precision data but neglected in LHC analyses, being enhanced at high energy, can even dominate over those from the anomalous TGCs considered. This limits the generality of the anomalous TGC constraints derived in current analyses, and necessitates extension of the analysis framework and change of physics interpretation. The issue will persist as we continue to explore the high energy frontier. We clarify and analyze the situation in the effective field theory framework, which provides a useful organizing principle for understanding Standard Model deviations in the high energy regime.
We propose a novel process where singly charged Higgs bosons are produced in a same-sign pair via vector boson fusion at hadron colliders in two Higgs doublet models. The process directly relates to the global symmetry structure of the Higgs potential. The produced charged Higgs bosons predominantly decay into a tau lepton and the neutrino or into a pair of top and bottom quarks, depending on the type of Yukawa interactions. We evaluate the signal and the background for the both cases at the CERN Large Hadron Collider and future higher-energy hadron colliders. We find that the process can be feasible and useful to explore the nature of the Higgs potential.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
