arXiv subjects

M. V. Tokarev

Publications and source records attributed to M. V. Tokarev.

21 records · Page 2Linked to original sources

arXiv1996

Experimental constraints on coefficients of $α_S$-expansion of Gottfried sum rule

The $x$- and $Q^2$-dependences of the Gottfried sum rule $S_G(x,Q^2)$ based on the experimental data on proton and deuteron structure functions are studied. The dependence of $S_G(x,Q^2)$ on $Q^2$ for low $x$ points to flavour asymmetry of sea quark distributions. For the first time, the coefficients $c_1, c_2$ of the expansion of $S_G(x,Q^2)$ in $α_S/π$ up to second order are evaluated through the phenomenological analysis of NMC and H1 data. It is found that $c_1$ is negative while $c_2$ is positive. The obtained result is in disagreement with QCD predictions for these coefficients. We suggest measuring the low $x$-dependence of the $F_2^D$ deuteron structure function at HERA in order to study the $Q^2$-dependence of the Gottfried sum rule.

hep-ph↗

arXiv1996

On a Possibility to Determine the Sign of the Polarized Gluon Distribution

We investigate the possibility to draw conclusions on the sign of the spin-dependent gluon distribution, $ΔG(x, Q^2)$, from existing polarized DIS data. The spin-dependent parton distributions $Δu_v, Δd_v, Δ{\bar u}, Δ{\bar d}, Δ{s}$, and $ΔG$ are constructed in the framework of a phenomenological procedure taking into account some assumptions on signs of valence and sea parton distributions motivated by 't Hooft's mechanism of quark-quark interaction induced by instantons. The axial gluon anomaly and data on integral quark contributions to the proton spin, $Δ\tilde u, Δ\tilde d$, and $Δ\tilde s$, are also taken into account. Predictions for the $x$- and $Q^2$-dependencies of the polarized proton and neutron structure functions, $g_1^p$ and $g_1^n$, are compared to experimental data. It is shown that the neutron structure function, $g_1^n$, is especially sensitive to the sign of $ΔG(x, Q^2)$. The results of our analysis supports the conclusion that this sign should be positive.

hep-ph↗

arXiv1996

On QCD $Q^2$-evolution of Deuteron Structure Function $F_2^D(x_D,Q^2)$ for $x_D>1$

The deep-inelastic deuteron structure function (SF) $F_2^D(x_D,Q^2)$ in the covariant approach in light-cone variables is considered. The $x_D$ and $Q^2$-dependences of SF are calculated. The QCD analysis of generated data both for non-cumulative $x_D<1$ and cumulative $x_D>1$ ranges was performed. It was shown that $Q^2$-evolution of SF is valid for ranges $0.275<x_D<0.85$ and $1.1<x_D<1.4$ for the same value of QCD scale parameter $Λ$. It was found the $x_D$-dependence of SF for the ranges is essentially different.

hep-ph↗