Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userThe Structure Function Ratios F2(Li)/F2(D) and F2(C)/F2(D) at small x
70
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We present the structure function ratios F2(Li)/F2(D) and F2(C)/F2(D) measured in deep inelastic muon-nucleus scattering at a nominal incident muon energy of 200 GeV. The kinematic range 0.0001 < x < 0.7 and 0.01< Q^2 < 70 GeV^2 is covered. For values of $x$ less than $0.002$ both ratios indicate saturation of shadowing at values compatible with photoabsorption results.
rate research
Read More
We report on a study of exclusive radiative decays of the Upsilon(1S) resonance into a final state consisting of a photon and two K0s candidates. We find evidence for a signal for Upsilon(1S)->gamma f_2(1525); f_2(1525)->K0sK0s, at a rate (4.0+/-1.3+/-0.6)x10^{-5}, consistent with previous observations of Upsilon(1S)->gamma f_2(1525); f_2(1525)->K+K-, and isospin. Combining this branching fraction with existing branching fraction measurements of Upsilon(1S)->gamma f_2(1525) and J/psi->gamma f_2(1525), we obtain the ratio of branching fractions: B(Upsilon(1S)->gamma f_2(1525))/B(J/psi->gamma f_2(1525))=0.09+/-0.02, approximately consistent with expectations based on soft collinear effective theory.
Inclusive electron-proton and electron-deuteron inelastic cross sections have been measured at Jefferson Lab (JLab) in the resonance region, at large Bjorken x, up to 0.92, and four-momentum transfer squared Q2 up to 7.5 GeV2 in the experiment E00-116. These measurements are used to extend to larger x and Q2 precision, quantitative, studies of the phenomenon of quark-hadron duality. Our analysis confirms, both globally and locally, the apparent violation of quark-hadron duality previously observed at a Q2 of 3.5 GeV2 when resonance data are compared to structure function data created from CTEQ6M and MRST2004 parton distribution functions (PDFs). More importantly, our new data show that this discrepancy saturates by Q2 ~ 4 Gev2, becoming Q2 independent. This suggests only small violations of Q2 evolution by contributions from the higher-twist terms in the resonance region which is confirmed by our comparisons to ALEKHIN and ALLM97.We conclude that the unconstrained strength of the CTEQ6M and MRST2004 PDFs at large x is the major source of the disagreement between data and these parameterizations in the kinematic regime we study and that, in view of quark-hadron duality, properly averaged resonance region data could be used in global QCD fits to reduce PDF uncertainties at large x.
Analyses of structure functions (SFs) from neutrino and muon deep inelastic scattering data have shown discrepancies in F2 for x < 0.1. A new SF analysis of the CCFR collaboration data examining regions in x down to x=.0015 and 0.4 < Q^2 < 1.0 is presented. Comparison to corrected charged lepton scattering results for F2 from the NMC and E665 experiments are made. Differences between muon and neutrino scattering allow that the behavior of F2 from muon scattering could be different from F2 from neutrino scattering as Q^2 approaches zero. Comparisons between F2 muon and F2 neutrino are made in this limit.
We report on the first measurement of the F2 structure function of the neutron from semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to < 100 MeV and their angles to < 100 degrees relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The F2n data collected cover the nucleon resonance and deep-inelastic regions over a wide range of Bjorken x for 0.65 < Q2 < 4.52 GeV2, with uncertainties from nuclear corrections estimated to be less than a few percent. These measurements provide the first determination of the neutron to proton structure function ratio F2n/F2p at 0.2 < x < 0.8 with little uncertainty due to nuclear effects.
The adsorption and diffusion of F2 molecules on pristine graphene have been studied using first-principles calculations. For the diffusion of F2 from molecular state in gas phase to the dissociative adsorption state on graphene surface, a kinetic barrier is identified, which explains the inertness of graphene in molecular F2 at room temperature, and its reactivity with F2 at higher temperatures. Studies on the diffusion of F2 molecules on graphene surface determine the energy barriers along the optimal diffusion pathways, which help to understand the high stability of fluorographene.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
