相关论文: Strangeness in the Nucleon
The total contribution of strange quarks to the intrinsic spin of the nucleon can be determined from a measurement of the strange-quark contribution to the nucleon's elastic axial form factor. We have studied the strangeness contribution to…
Effective quark magnetic moments are extracted from experimental measurements as a function of the strangeness magnetic moment of the nucleon. Assumptions made in even the most general quark model analyses are ruled out by this…
The strange form factors of the nucleon are studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. A comparison with the available experimental world data from the SAMPLE, PVA4, HAPPEX…
The properties of the nucleons in nuclear medium have been investigated in the context of the flux tube model incorporating strangeness $(s\bar{s})$ contribution to proton structure in conformity with the experimental indication. Proton is…
We revisit the classical relation between the strangeness content of the nucleon, the pion-nucleon sigma term and the $SU(3)_F$ breaking of the baryon masses in the context of Lorentz covariant chiral perturbation theory with explicit…
The strangeness contribution to the vector and axial form factors of the proton is presented for momentum transfers in the range 0.45 < $Q^2$ < 1.0 GeV$^2$. The results are obtained via a combined analysis of forward-scattering…
Using heavy baryon chiral perturbation theory to one loop, we derive an analytic and parameter-free expression for the momentum dependence of the strange magnetic form factor of the nucleon $G_M^{(s)} (Q^2)$ and its corresponding radius.…
After the EMC and subsequent experiments at CERN, SLAC and DESY on the deep inelastic scattering of polarized leptons on polarized nucleons, it is now established that the Q^2=0 value of the axial strange form factor of the nucleon, a…
Intrinsic strangeness contributions to low-energy strange quark matrix elements of the nucleon are modelled using kaon loops and meson-nucleon vertex functions taken from nucleon-nucleon and nucleon-hyperon scattering. A comparison with…
This study delves into the contribution of the strange quark within the proton, which influences several fundamental proton properties. By establishing a robust relationship between the proton's quantum anomalous energy and the sigma term,…
The present empirical information on the strangeness form factors indicates that the corresponding $uuds\bar s$ component in the proton is such that the $uuds$ subsystem has the flavor spin symmetry $[4]_{FS}[22]_F[22]_S$ and mixed orbital…
The strangeness magnetic moment of the proton is shown to be small in the chiral quark model. The dominant loop contribution is due to kaons. The K^* loop contributions are proportional to the difference between the strange and light…
The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The…
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…
The strangeness content of nucleon form factors is analyzed in a two-component model with a quark-like intrinsic structure surrounded by a meson cloud. A comparison with the available experimental data from the SAMPLE, PVA4, HAPPEX and G0…
The strange quark scalar content plays an important role in both the description of nucleon structure and in the determination of dark matter direct detection cross sections. As a measure of the strange-quark contribution to the nucleon…
The scalar strangeness content of the nucleon, characterized by the so-called strangeness-nucleon sigma term, is of fundamental importance in understanding its sea-quark flavor structure. We report a determination of the octet baryon sigma…
The contributions of strange quarks to the nucleon mass and the nucleon spin are investigated in a mixed action scheme employing domain wall valence quarks and quark loops on MILC asqtad dynamical fermion ensembles. Results are presented…
The strange form factors of the proton are basic to an understanding of proton structure, and are presently the focus of many experiments. Before the strangeness effects can be extracted from data, it is necessary to calculate and remove…
We present results on the spin and quark content of the nucleon using $N_f=2$ twisted mass clover-improved fermion simulations with a pion mass close to its physical value. We use recently developed methods to obtain accurate results for…