Related papers: Improved method for calculating nucleon strangenes…
We calculate the intrinsic strangeness of the nucleon, <N|ss|N> - <0|ss|0>, using the MILC library of improved staggered gauge configurations using the Asqtad and HISQ actions. Additionally, we present a preliminary calculation of the…
Measurement of the neutral weak vector form factors of the nucleon provides unique access to the strange quark content of the nucleon. These form factors can be studied using parity-violating electron scattering. A comprehensive program of…
In this paper a discussion is made of the article by the HERMES Collaboration, Phys.Lett. B666,446, where several important results concerning strange quark properties in the nucleon were presented. By analysing the sum of K+-…
We present preliminary results for strangeness form factors of the nucleon computed on the CLS ensembles with $N_f=2+1$ flavors of O($a$)-improved Wilson fermions. Our calculations are performed at two values of the lattice spacing ($a \in…
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…
We calculate cumulants of fluctuations of net-baryon number, net-electric charge and net-strangeness, in the framework of lattice regularized QCD. We use a highly improved staggered quark (HISQ) action on lattices with temporal extent of…
Flavour singlet contributions to the nucleon spin are elusive due to the fact that they cannot be determined directly in experiment but require extrapolations to the small x region. Direct calculations of these contributions are possible…
We calculate the second, fourth and sixth order quark number fluctuations in the deconfined phase of 2+1 flavor QCD using lattices with temporal extent Nt=4, 6, 8 and 12. We consider light, strange and charm quarks. We use p4 action for…
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…
Theoretical approaches to strange and other types of quark matter accounted for at the SQM2003 Meeting are reviewed. They range from simple statistical models through perturbative QCD supported mico-dynamical simulations til lattice gauge…
We present the N_f=2+1 clover fermion lattice QCD calculation of the nucleon strangeness form factors. We evaluate disconnected insertions using the Z(4) stochastic method, along with unbiased subtractions from the hopping parameter…
Observables from parity violation in elastic electron-nucleon scattering and neutral current quasi-elastic neutrino-nucleus scattering are employed as tools to improve the current knowledge on the strangeness content in the nucleon.
The nucleon strange and anti-strange distribution asymmetry is an important issue in the study of the nucleon structure. In this work, we show that the heavy quark recombination processes from a perturbative QCD picture can give a sizable…
We determine the nucleon axial, scalar and tensor charges and the nucleon $\sigma$-terms using twisted mass fermions. We employ three ensembles with approximately equal physical volume of about 5.5~fm, three values of the lattice spacing,…
The strangeness degrees of freedom in the parton structure of the nucleon are explored in the global analysis framework, using the new CTEQ6.5 implementation of the general mass perturbative QCD formalism of Collins. We systematically…
The nucleon axial form factor is a dominant contribution to errors in neutrino oscillation studies. Lattice QCD calculations can help control theory errors by providing first-principles information on nucleon form factors. In these…
Determination of baryon number (or mass) distribution of the strangelets, that may fragment out of the warm and excited strange quark matter ejected in the merger of strange stars in compact binary stellar systems in the Galaxy, is…
It has proven a significant challenge to experiment and phenomenology to extract precise values of the nucleon sigma terms. This difficulty opens the window for lattice QCD simulations to lead the field in resolving this aspect of nucleon…
We analyze the effect of a variation of the strange nucleon matrix element $\langle N| m_s \bar{s}s|N\rangle$ on the abundances of the light elements produced in the Big Bang. For that, we vary the nucleon mass in the leading eight…
The structure of the quark propagator of $QCD$ in a confining background is not known. We make an Ansatz for it, as hinted by a particular mechanism for confinement, and analyze its implications in the meson and baryon correlators. We…