相关论文: NON-SINGLET STRUCTURE FUNCTIONS AT SMALL X

The proton spin dependent structure function $g_1^p$ is analysed using the unified scheme incorporating both Altarelli-Parisi evolution and the double $ln^2(1/x)$ effects at low $x$. The latter are found to be very important in the region…

The behaviour of the quark coefficient function for the longitudinal structure function F_L in deep-inelastic scattering is investigated for large values of the Bjorken variable x. We combine a highly plausible conjecture on the large-x…

We examine critically the evidence for deviations from next-to-leading order perturbative DGLAP evolution in HERA data. We briefly review the status of perturbative small-x resummation and of global determinations of parton distributions.…

We extract the deep inelastic scattering cross-sections ratio $R= \sigma _L/\sigma _T$ in the range $10^{-4} \leq x \leq 10^{-1}$ from $F_2$ HERA data using very simple relations based on perturbative QCD. The result depends on only one…

In the leading twist approximation of the Wilson operator product expansion with "frozen" and analytic strong coupling constants we show that Bessel-inspired behavior of the structure function F2 at small x, obtained for a flat initial…

A summary of recent results reported in the Structure Functions and Low-x working group at the DIS 2009 Workshop is given. Recent measurements of deep inelastic scattering cross sections and structure functions at HERA and of proton…

Q**2 dependence of nuclear structure functions is important for understanding perturbative QCD in nuclear environment. However, current experimental data are not sufficient for studying nuclear dependence in the Q**2 evolution because the…

Structure function data together with other measurements from fixed-target deep inelastic scattering and hadron-hadron collider experiments which contribute to our knowledge of the parton density functions are reviewed. The inclusive…

We pursue the hypothesis that the events with a large rapidity gap, observed at HERA, reflect the scattering of electrons off lumps of wee partons inside the proton. A simple scaling behaviour is predicted for the diffractive structure…

We have studied the physical evolution kernels for nine non-singlet observables in deep-inelastic scattering (DIS), semi-inclusive e^+e^-annihilation and the Drell-Yan (DY) process, and for the flavour-singlet case of the photon- and…

We derive an energy density functional for non-relativistic spin one-half fermions in the limit of a divergent two-body scattering length. Using an epsilon expansion around d=4-epsilon spatial dimensions we compute the coefficient of the…

We present a comprehensive study of high-energy double logarithms in inclusive DIS. They appear parametrically as alpha_s^n ln^{2n-k} x at the n-th order in perturbation theory in the splitting functions for the parton evolution and the…

Study of parton distribution function (PDF) is a topic of significant interest in QCD. To overcome the shortcomings of conventional PDFs, several alternative methods have been suggested in recent years. The present work reports the x…

We briefly discuss recent results on the evolution of unpolarized parton densities and structure functions in massless perturbative QCD. Present partial results on the next-to-next-to-leading order (NNLO) evolution kernels prove sufficient…

We review recent developments in the determination of parton densities from deep inelastic and related data. We show how the asymmetries observed in the W+- rapidity distributions and in pp/pn Drell-Yan production further constrain the…

Quark-hadron duality is studied in a systematic way for both the unpolarized and polarized structure functions, by taking into account all the available data in the resonance region.In both cases, a detailed perturbative QCD based analysis…

In this paper, we analyze the scaling behavior of \emph{Diffusion Limited Aggregation} (DLA) simulated by Hastings-Levitov method. We obtain the fractal dimension of the clusters by direct analysis of the geometrical patterns in a good…

These notes are a summary of our efforts to answer the question in the title. Our answer is in the affirmative as: (i) HERA data indicate a large value of the gluon structure function; (ii) no contradictions with the asymptotic predictions…

This is a talk given at Ringberg Workshop:"New Trends in HERA Physics", 30 May - 4 June, 1999.In this talk we discuss how deeply the region of high parton densities has been studied experimentally at HERA. We show that the measurements of…

We present the results of our QCD analysis for nonsinglet unpolarized quark distributions and structure function $F_2(x,Q^2)$. New parameterizations are derived for the nonsinglet quark distributions for the kinematic wide range of $x$ and…