Investigation of proton structure function F_(2)^(p)at HERA in light of an analytical solution to the Balitsky–Kovchegov equation

In this paper,the proton structure function F_(2)^(p)(x,Q^(2))at small-x is investigated using an analytical solution to the Balitsky–Kovchegov(BK)equation.In the context of the color dipole description of deep inelastic scattering(DIS),the structure function F_(2)^(p)(x,Q^(2))is computed by applying the analytical expression for the scattering amplitude N(k,Y)derived from the BK solution.At transverse momentum k and total rapidity Y,the scattering amplitude N(k,Y)represents the propagation of the quark-antiquark dipole in the color dipole description of DIS.Using the BK solution we extracted the integrated gluon density xg(x,Q^(2))and then compared our theoretical estimation with the LHAPDF global data fits,NNPDF3.1sx and CT18.Finally,we have investigated the behavior of F_(2)^(p)(x,Q^(2))in the kinematic region of 10^(-5)≤x≤10^(-2)and 2.5 GeV^(2)≤Q^(2)≤60 GeV^(2).Our predicted results for F_(2)^(p)(x,Q^(2))within the specified kinematic region are in good agreement with the recent high-precision data for F_(2)^(p)(x,Q^(2))from HERA(H1 Collaboration)and the LHAPDF global parametrization group NNPDF3.1sx.

Analytic expression for the proton structure function in deep inelastic scattering

The analytic expression of proton in deep inelastic scattering is studied by using the color glass condensate model and the dipole picture. We get a better description of the HERA DIS data than the GBW model which was inspired by the Glauber model. We find that our model satisfies the unitarity limit and Froissart Bound which refers to an energy dependence of the total cross-section rising no more rapidly than ln^2 s.

Parton physics from large-momentum effective field theory

Parton physics,when formulated as light-front correlations,are difficult to study non-perturbatively,despite the promise of lightfront quantization.Recently an alternative approach to partons have been proposed by re-visiting original Feynman picture of a hadron moving at asymptotically large momentum.Here I formulate the approach in the language of an effective field theory for a large hadron momentum P in lattice QCD,LaMET for short.I show that using this new effective theory,parton properties,including light-front parton wave functions,can be extracted from lattice observables in a systematic expansion of 1/P,much like that the parton distributions can be extracted from the hard scattering data at momentum scales of a few GeV.

Gluon number fluctuations with heavy quarks at HERA

We study the effect of gluon number fluctuations （Pomeron loops） on the proton structure function at HERA. It is shown that the description of charm and bottom quarks and longitudinal structure functions are improved, with x^2/d.o.f=0.803 （fluctuations） as compared with x^2/d.o.f=0.908 （without fluctuations）, once the gluon number fluctuations are included. We find that in the gluon number fluctuation case the heavy quarks do not play an important role in the proton structure function as the saturation model. The successful description of the HERA data indicates that the gluon number fluctuation could be one of the key mechanisms to describe the proton structure function at HERA energies.

Gluon number fluctuations and diffusive scaling effect

The diffusive scaling is studied based on pomeron loop equations in the fixed coupling case. At Y 〉〉 YDS, the gluon number fluctuations become important, the geometric scaling is replaced by the diffusive scaling. In the diffusive scaling regime, the deep inelastic scattering （DIS） total scattering cross-section is a function of single variable ln[1/（r^2Qs^2（z））]. We show that the deep inelastic scattering experimental data lie on a single curve, which seems to indicate the existence of the diffusive scaling phenomenology in the deep inelastic scattering.

Magnetic and electro-catalytic properties of a copper complex with 2-(pyridylmethyl)amino-N,N-bis(2-methylene-4,6-difluorophenol)

A new material for both magnetic coupling and electrocatalytic hydrogen generation based on a copper complex,[（HL）CuCl-CuCl（HL）]HCl 1 is prepared by the reaction of 2-（pyridylmethyl）amino-N,N-bis（2-methylene-4,6-difluorophenol）（H2L） and CuCl2·2H2O.In solid,complex 1 is built from two copper units（[（HL）CuCl]）,and exhibits an antiferromagnetic exchange interaction between copper（Ⅱ） ions（J=-160cm^-1）.In liquid,1 can electrocatalyze hydrogen generation both from acetic acid with a turnover frequency（TOF） of 16.3 moles of hydrogen per mole of catalyst per hour at an overpotential（OP）of 941.6 mV（in DMF）,and a neutral buffer with a TOF of 1415.6 moles of hydrogen per mole of catalyst per hour at an OP of 787.6 mV.