Related papers: New Structure Function Results at Low x and High Q…
A small electromagnetic sampling calorimeter, installed in the ZEUS experiment in 1995, significantly enhanced the acceptance for very low x and low Q^2 inelastic neutral current scattering, e^{+}p \to e^{+}X, at HERA. A measurement of the…
I investigate what a direct measurement of the longitudinal structure function F_L(x,Q^2) could teach us about the structure of the proton and the best way in which to use perturbative QCD for structure functions. I assume HERA running at a…
Using 3.9 $pb^{-1}$ of data from ep $\ra$ eX interactions recorded using the ZEUS detector in 1997,the proton structure function, F$_2$, has been measured in the range 0.015 GeV$^2$ $<$ Q$^2 <$ 0.65 GeV$^2$ and $6 \times 10^{-7} < x < 1…
In the following article we describe our measurement of the proton structure function $F_2$ and of the gluon momentum density $xg$ in $ep$ collisions with the ZEUS detector at HERA in 1993. The results for $F_2$ confirm our measurement from…
A measurement of the inclusive cross section for the deep-inelastic scattering of positrons off protons at HERA is presented at momentum transfers $8.5 \leq Q^2 \leq 35 GeV^2$ and large inelasticity $y = 0.7$, i.e. for the Bjorken-x range…
The strikingly different high energy behaviours of real photoabsorption cross-sections with Q^2 = 0 and the low x proton structure function at large Q^2 are studied from a laboratory frame viewpoint, in which the x and Q^2 dependence…
HERA $ep$ collider provides unique information on the proton structure. High center of mass energy $s=320$ GeV gives access to both the low Bjorken-$x$ domain and regime of high momentum transfers $Q$. Recently the H1 collaboration reported…
Measurements of the proton structure function $F_2$ in the $Q^2$ range $0.6 - 17 \rm GeV^2$ from ZEUS 1995 shifted vertex data and $Q^2 \simeq 1.5 - 20000 \rm GeV^2$ from 1996 and 1997 ZEUS data are presented. From the former and other ZEUS…
Recent results on structure functions and parton distribution functions at HERA are presented. Results on the measurements of the structure functions F2, FL and F3 will be covered, as well as the results of the most recent QCD fits to…
The results are presented of a study of the accuracy one may achieve at HERA in measuring the strong coupling constant $\alpha_s$ and the gluon distribution $xg(x,Q^{2})$ using future data of the structure function $F_{2}(x,Q^{2})$ which…
An extraction of the longitudinal proton structure function FL(x,Q2) from H1 data at low Q2 (about 1 GeV2) and low Bjorken x (about 0.00005) is reported. The analysis is based on the data collected in a dedicated low Q2 running period in…
Recent results from the HERA experiment H1 on the longitudinal stucture function $F_{L}$ of the proton are presented. They include proton structure function analyses with particular emphasis on those kinematic regions which are sensitive to…
First attempts are described to determine the unintegrated Parton Density Function of the gluon from a fit to measurements of the structure function $F_2(x,Q^2)$ and also $F_2^c(x,Q^2)$ measured at HERA. Reasonable descriptions of both…
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…
Recent structure function results from the H1 and ZEUS Collaborations are presented. The data cover a wide kinematic range of squared four-momentum transfers Q^2, from 0.2 GeV^2 to 30000 GeV^2, and Bjorken x between 5*10^-6 and 0.65. Data…
Measurements of the proton and deuteron $F_2$ structure functions are presented. The data, taken at Jefferson Lab Hall C, span the four-momentum transfer range $0.06 < Q^2 < 2.8$ GeV$^2$, and Bjorken $x$ values from 0.009 to 0.45, thus…
We discuss how the proton structure function F2 is described in the HERA kinematic range by double asymptotic expressions for low x and large Q^2. From a NLO double asymptotic approximation of recent data from the H1 experiment at HERA we…
The charm quark structure function $F^c_2$ and the longitudinal structure function $F_l^p$ are directly sensitive to the gluon content of proton and therefore are crucial in understanding of proton structure function, in particular at low…
From the new measurement of F_L at HERA we derive fixed-Q^2 averages <F_L/F_2>. We compare these with bounds which are rigorous in the framework of the standard dipole picture. The bounds are sharpened by including information on the charm…
Recent experimental results contributing to the understanding of the structure of the nucleon are reviewed. They include the final NMC results on proton and deuteron structure functions; a re-analysis of the CCFR data on F2 and xF3; new…