Seminar “Hadron Physics”

Date and Time: Friday, 22 November 2019, at 11:00 AM

Venue: Blokhintsev Hall (4th floor), Bogoliubov Laboratory of Theoretical Physics

Seminar topic: “Extracting the longitudinal structure function F_L(x,Q²) at small x from a Froissart-bounded parametrization of F₂(x,Q²)”

Speaker: A. V. Kotikov

Abstract:

We present a method to extract, in the leading and next-to-leading order approximations, the longitudinal deep-inelastic scattering structure function F_L(x,Q²) from the experimental data by relying on a Froissart-bounded parametrization of the transversal structure-function F₂(x,Q²) and, partially, on the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equations. Particular attention is paid on the kinematics of low and ultra-low values of the Bjorken variable x. Analytical expressions for F_L(x,Q²) in terms of the effective parameters of the parametrization of F₂(x,Q²) are presented explicitly. We argue that the obtained structure functions F_L(x,Q²) within both, the leading and next-to-leading order approximations, manifestly obey the Froissart boundary conditions. Numerical calculations and comparison with available data from ZEUS and H1-Collaborations at HERA demonstrate that the suggested method provides reliable structure functions F_L(x,Q²) at low x in a wide range of the momentum transfer (1~\GeV² < Q² < 3000~\GeV²) and can be applied as well in analyses of ultra-high energy processes with cosmic neutrinos.

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