相关论文: Small Strange Quark Content of Protons
A survey of the experimental data on the charge and strong hadronic radii is given. A new, however preliminary value of the \Sigma^- charge radius allows to include also hyperons in the systematics. The presented data on the hadronic radii…
We consider determinations of the strange sea in the nucleon based on the QCD analyses of data collected at the LHC with focus on the recent high-statistics ATLAS measurement of the $W^\pm$- and $Z$-boson production. We study the effect of…
The implications of the empirical signatures for the positivity of the strangeness magnetic moment $\mu_s$, and the negativity of the strangeness contribution to the proton spin $\Delta_s$, on the possible $uuds\bar s$ configurations of…
I discuss low-energy pion-nucleon scattering in the framework of chiral perturbation theory. I argue that using this theoretical method one is able to handle the in some cases tremendous experimental accuracy (for the low partial waves). I…
I review progress on selected issues connected with generalized parton distributions. Topics range from the description of hard exclusive reactions to the spatial distribution of quarks in the nucleon and the contribution of their orbital…
The object of this brief review is to reconcile different points of view on how the spin of proton is made up from its constituents. On the basis of naive quark model with flavour symmetry such as isospin or SU(3) one finds a static…
In this paper I review a number of recent results in the field of exotic atoms. Recent experiments or ongoing experiments with muonic, pionic and antiprotonic hydrogen, as well as recent measurement of the pion mass are described. These…
Sea quark contributions to the scalar density and the axial current matrix elements of the nucleon are studied in lattice qcd with two flavours of dynamical wilson fermions. the results are compared to trends in heavy quark mass expansions,…
There is a prejudice that the chiral soliton model of baryons is something orthogonal to the good old constituent quark models. In fact, it is the opposite: the spontaneous chiral symmetry breaking in strong interactions explains the…
There have been several reports of exotic nuclear fragments, with highly unusual charge to mass ratio, in cosmic ray experiments. Although there exist experimental uncertainties which make them, at best, only candidate "exotic" events, it…
The first moment the chirality-odd twist-3 parton distribution $e(x)$ is related to the pion-nucleon $\sigma$-term which is important for phenomenology. However, the possible existence of a singular contribution proportional to $\delta(x)$…
A statistical framework in conjugation with the principle of detailed balance is employed to examine the low-energy properties i.e. charge radii and quadrupole moment of J$^P$=$\frac{1}{2}^+$ octet and J$^P$=$\frac{3}{2}^+$ decuplet baryon.…
The chiral quark model with a broken U(3) symmetry gives a simple and unified account for the proton spin and flavor puzzles, as well as the octet baryon magnetic moments.
We present a calculation of the nucleon sigma term on two-flavor QCD configurations with dynamical overlap fermions. We analyse the lattice data for the nucleon mass using the baryon chiral perturbation theory. Using partially quenched data…
It is shown that, based only on two empirically known facts besides two reasonable theoretical postulates, we are inevitably led to a conclusion that the quark orbital angular momentum carries nearly half of the total nucleon spin. We also…
We report on recent lattice QCD calculations of the strangeness magnetic moment of the nucleon and the nucleon electromagnetic form factors, when we allow the electromagnetic current to connect to quark loops as well as to the valence…
The NC and CC scattering of neutrino(antineutrino) on protons and nuclei with isotopic spin equal to zero is considered. It is shown that the measurement of the neutrino-antineutrino asymmetry in these processes could allow to obtain…
We present an analytic and parameter-free expression for the momentum dependence of the strange magnetic form factor of the nucleon and its corresponding radius which has been derived in Heavy Baryon Chiral Perturbation Theory. We also…
In these proceedings we discuss recent progress in nucleon structure using lattice QCD simulations at or near the physical value of the pion mass. Main focus will be given in observables such as the nucleon axial charge and the first…
We review some aspects of spin physics where QCD instantons play an important role. In particular, their large contributions in semi-inclusive deep-inelastic scattering and polarized proton on proton scattering. We also review their…