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A fit is made to the data for the proton structure function up to Q^2=10 GeV^2, including the real gamma p total cross-section. It is economical and simple, and its form is motivated by physical principles. It is extrapolated down to very…

High Energy Physics - Phenomenology · Physics 2009-10-22 A Donnachie , P V Landshoff

We observe that the DGLAP evolution equations at NNLO analysis predicts a ratio of the structure functions in region of small Bjorken variable $x$. The ratio $F_{L}(x,Q^{2})/F_{2}(x,Q^{2})$ is obtained and compared with the prediction of…

High Energy Physics - Phenomenology · Physics 2019-08-09 G. R. Boroun , B. Rezaei

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…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ewelina Maria Lobodzinska

New results from the H1 and ZEUS collaborations on the measurement of cross-sections at very high Q^2 (up to 25000 GeV^2) and on the proton structure function F_2(x,Q^2) for momentum transfers squared Q^2 >= 1.5 GeV^2 and Bjorken x >= 3.5…

High Energy Physics - Experiment · Physics 2007-05-23 Gregorio Bernardi

The neutron structure function F2n(x) is evaluated within the kinematic range 10**(-3)<x<1 from the deuteron and proton data by employing relativistic theoretical description of F2D(x) and several assumptions on the hihg-x asymptotics of…

High Energy Physics - Phenomenology · Physics 2015-06-25 George I. Smirnov , Valery V. Burov , Alexander V. Molochkov , Hiroshi Toki

In the semiclassical approach, inclusive and diffractive quark and gluon distributions are expressed in terms of correlation functions of Wilson loops. Each Wilson loop integrates the colour field strength in the area between the…

High Energy Physics - Phenomenology · Physics 2010-03-25 W. Buchmuller , T. Gehrmann , A. Hebecker

The drastic rise of the proton structure function F_2(x,Q^2) when the Bj\"orken variable x decreases, seen at HERA for a large span of Q^2, negative values for the 4-momentum transfer, may be damped when Q^2 increases beyond several…

High Energy Physics - Phenomenology · Physics 2014-11-17 P. Desgrolard , A. Lengyel , E. Martynov

The proton structure function in the diffraction region of small Bjorken-$x$ and $10 {\rm GeV}^2 \le Q^2 \le 100 {\rm GeV}^2$ behaves as $F_2 (x, Q^2) = F_2 (W^2) = f_0 \cdot (W^2)^{C_2}$, where $x = Q^2 / W^2$. The exponent $C_2$ of the…

High Energy Physics - Phenomenology · Physics 2011-04-06 Dieter Schildknecht

The use of the differential gluon structure function of the proton ${\cal F}(x,Q^{2})$ introduced by Fadin, Kuraev and Lipatov in 1975 is called upon in many applications of small-x QCD. We report here the first determination of ${\cal…

High Energy Physics - Phenomenology · Physics 2014-11-17 I. P. Ivanov , N. N. Nikolaev

We present an extraction of the lowest three moments of the proton longitudinal structure function F_L from world data between Q^2 = 0.75 and 45 (GeV/c)^2. The availability of new F_L data at low Bjorken x from HERA and at large x from…

Nuclear Experiment · Physics 2013-10-22 P. Monaghan , A. Accardi , M. E. Christy , C. E. Keppel , W. Melnitchouk , L. Zhu

The gluon contributions to $F_L(x,Q^2)$ in ${\cal O}(\alpha_s)$ are calculated taking into account the transverse momentum of the initial state parton. In comparison with collinear factorization $F_L(x,Q^2)$, is not affected at large $x$…

High Energy Physics - Phenomenology · Physics 2009-10-28 Johannes Blümlein

We present a QCD analysis of the proton structure function $F_2$ measured by the H1 experiment at HERA, combined with data from previous fixed target experiments. The gluon density is extracted from the scaling violations of $F_2$ in the…

High Energy Physics - Experiment · Physics 2012-08-27 H1 Collaboration

The Q^2 dependence of inclusive electron-proton scattering F_2 structure function data in both the nucleon resonance region and the deep inelastic region, at momentum transfers below 5 (GeV/c)^2, is investigated. Moments of F_2 are…

High Energy Physics - Phenomenology · Physics 2014-11-17 C. S. Armstrong , R. Ent , C. E. Keppel , S. Liuti , G. Niculescu , I. Niculescu

$Q^2$ evolution of structure functions in the nucleon and nuclei is investigated by using usual DGLAP equations and parton-recombination equations. Calculated results for proton's $F_2$ and for the ratio $F_2^{Ca}/F_2^D$ are compared with…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Miyama

Self-similarity based model of proton structure function at small \textit{x} was reported in the literature sometime back. The phenomenological validity of the model is in the kinematical region $ 6.2\, \times \, 10^{-7} \leq x \leq…

High Energy Physics - Phenomenology · Physics 2014-04-28 Akbari Jahan , D. K. Choudhury

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…

High Energy Physics - Phenomenology · Physics 2017-08-23 R. S. Thorne

We compute the proton structure function F_2^p at small x and large Q^2 at next-to-leading order in alpha_s(Q^2), including summations of all leading and subleading logarithms of Q^2 and 1/x in a way consistent with momentum conservation.…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. D. Ball , S. Forte

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…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Quadt

We present a global fit to the structure function F_2 measured in lepton-proton experiments at small values of Bjorken-x, x< 0.01, for all experimentally available values of Q^2, 0.045< Q^2 < 800 GeV^2, using the Balitsky -Kovchegov…

High Energy Physics - Phenomenology · Physics 2009-06-16 J. L. Albacete , N. Armesto , J. G. Milhano , C. A. Salgado

Measurements of the proton structure function F_2 for 0.11 < Q^2 < 20000 GeV^2 and 1.2 X 10^-5 < x < 0.65 from ZEUS 1994-1997 measurements are presented. From ZEUS 1994 and 1995 F_2 data the slopes d(F_2)/d(ln Q^2) at fixed x and d(ln…

High Energy Physics - Experiment · Physics 2007-05-23 Richard Cross