Related papers: Charge Symmetry Breaking in Parton Distribution Fu…
W and Z bosons will be produced copiously at the LHC proton-proton collider. We study the parton distribution dependence of the total production cross sections and rapidity distributions, paying particular attention to the uncertainties…
A search for the violation of the charge-parity ($CP$) symmetry in the production of top quarks in association with Z bosons is presented, using events with at least three charged leptons and additional jets. The search is performed in a…
Understanding the fundamental structure of matter requires an understanding of how quarks and gluons are assembled to form hadrons and of the structure of the protons which are the colliding particles at LHC. The arrangement of quarks and…
The parton distribution functions determined by CTEQ at low $Q^2$ are used as inputs to test the validity of the valon model. The valon distributions in a nucleon are first found to be nearly $Q$ independent. The parton distribution in a…
We review important aspects of QCD in the continuum and on the lattice and take a look at the fate of its symmetries with an emphasis on chiral symmetry breaking on the lattice.
High precision measurements of the parity-violating asymmetry in polarized electron scattering from nuclei can be used to extract information on nuclear and nucleon structure or to determine Standard Model couplings and higher-order…
We show that the correction to the Paschos-Wolfenstein relation associated with charge symmetry violation in the valence quark distributions is essentially model independent. It is proportional to a ratio of quark momenta that is…
A popular framework for exploring Lorentz violation is the Standard Model Extension. This extension contains a large number of parameters that can be bounded in various experiments. Most studies, however, focus on the fermion or photon…
We extend the study of lowest moments, $<x>$ and $<x^2>$, of the parton distribution function of the nucleon to include those of the sea quarks; this entails a disconnected insertion calculation in lattice QCD. This is carried out on a…
In recent years, there has been a breakthrough in lattice calculations of $x$-dependent partonic distributions. This encompasses also distributions describing the 3D structure of the nucleon, such as generalized parton distributions (GPDs).…
The possible discovery of proton decay, neutron-antineutron oscillation, neutrinoless beta decay in low energy experiments, and exotic signals related to the violation of the baryon and lepton numbers at collider experiments will change our…
We calculate the scalar and tensor charges of the nucleon in 2+1-flavor lattice QCD, for which the systematics of the renormalization of the disconnected diagram is well controlled. Numerical simulations are performed at a single lattice…
Recent progress in hadron structure calculations within lattice QCD is reviewed. Results on key observables such as the axial charge, the quark momentum fraction and the spin content of the nucleon are discussed with focus on open issues.…
A significant asymmetry in baryon/antibaryon yields in the central region of high energy collisions is observed when the initial state has non-zero baryon charge. This asymmetry is connected with the possibility of baryon charge diffusion…
A new approach to determine the LHC luminosity is investigated. Instead of employing the proton-proton luminosity measurement, we suggest to measure directly the parton-parton luminosity. It is shown that the electron and muon…
We have performed the first global QCD analysis to include the CCFR and NuTeV dimuon data, which provide direct constraints on the strange and anti-strange parton distributions, $s(x)$ and $\bar{s}(x)$. To explore the strangeness sector, we…
We calculate electric and baryonic charge fluctuations on the lattice. Results have been obtained with the highly improved staggered quark action (HISQ) and almost physical quark masses on lattices with spacial extent of $N_\tau=6,8,12$.…
The distributions of pressure and shear forces inside the proton are investigated using lattice Quantum Chromodynamics (LQCD) calculations of the energy momentum tensor, allowing the first model-independent determination of these…
Protons and neutrons have a rich structure in terms of their constituents, the quarks and gluons. Understanding this structure requires solving Quantum Chromodynamics (QCD). However QCD is extremely complicated, so we must numerically solve…
The asymmetry in the angular distribution of n p --> d pi^0 due to Charge Symmetry Breaking is calculated using Heavy Baryon Chiral Perturbation Theory. Recent developments in power counting have proven successful in describing total cross…