Small x phenomenology on gluon evolution through the BFKL equation in light of a constraint in multi-Regge kinematics

Abstract

We investigate the impact of so called kinematic constraint on gluon evolution at small x. Implanting the constraint on the real emission term of gluon ladder diagram, we obtain an integrodifferential form of BFKL equation. Later we solve the equation analytically using the method of characteristics. We sketch the Bjorken x and transverse momentum k 2 t dependence of our solution of unintegrated gluon distributions f (x, k 2 t ) in kinematic constraint supplemented BFKL equation and contrasted the same with original BFKL equation. Then we extract the collinear gluon density xg(x, Q 2 ) from unintegrated gluon distributions f (x, k 2 t ) and compared our theoretical prediction with that of global data fits viz. NNPDF3.1sx and CT14. Finally we assess the sensitivity of f (x, k 2 t ) towards BFKL intercept λ for three canonical choices of λ viz. o.4, 0.5 and 0.6.As a consequence of these BFKL kinematics, so-called kinematic constraint or consistency constraint comes into the * pragyanp@tezu.ernet.in † mlalung@tezu.ernet.in ‡ jks@tezu.ernet.in

Investigation of proton structure function F2p at HERA in light of an analytical solution to the Balitsky–Kovchegov equation

“…The collaborations at HERA contributed high-precision data for measuring the proton structure function F p 2 at different kinematical regions of x and Q 2 [27,28]. Some recent works on the measurement of proton structure functions using various evolution equations and approaches are described in [29][30][31][32][33], and the results correlate well with the experimental data. In [34], for the first time, the reproduction of measurements of the DIS proton structure function at high energy from the color dipole description in momentum space was investigated.…”

On the different forms of the kinematical constraint in BFKL

“…The understanding of action of the kinematical constraint across the whole region of z will be particularly important for ongoing efforts to unify the BFKL and DGLAP evolution schemes [55,56,57] where effects of kinematical constrains may play a crucial role. Furthermore, the inclusion of the kinematical constraint is known to be relevant for BFKL phenomenology [20,58,59,60,61,62,63]. However, so far only the simplest version of it was used in the context of BFKL.…”