Measurement of beauty photoproduction near threshold using di-electron events with the H1 detector at HERA

Abstract

The cross section for ep → e bbX in photoproduction is measured with the H1 detector at the ep-collider HERA. The decay channel bb → eeX is selected by identifying the semi-electronic decays of the b-quarks. The total production cross section is measured in the kinematic range given by the photon virtuality Q 2 ≤ 1 GeV 2 , the inelasticity 0.05 ≤ y ≤ 0.65 and the pseudorapidity of the b-quarks |η(b)|, |η(b)| ≤ 2. The differential production cross section is measured as a function of the average transverse momentum of the beauty quarks

CGC/saturation approach: an impact-parameter dependent model for diffraction production in DIS

“…The experimental data for diffractive production in DIS (see Ref. [40]) are presented using the following set of the kinematic variables:…”

DGLAP evolution for DIS diffraction production of high masses

“…Using Eq. (25b) we attempted to describe the combined set of the inclusive diffractive cross sections measured by H1 and ZEUS collaboration at HERA [21]. The measured cross sections were expressed in terms of reduced cross sections, σ D(4) r , which is related to the measured ep cross section by…”

“…In the experimental data from Ref. [21] the integral in t was performed in the region 0.09 ≤ t ≤ 0.55 GeV 2 , while our formulae are derived for the integration in t from 0 to ∞. Assuming that the b-dependence of the saturation scale Q s (Y 0 , b) is the same as was suggested in Ref.…”

“…(42) with the experimental data, choosing 42 experimental points (see Ref. [21]) with β ≤ 0.056. All other kinematic variables were the same, as in section III, in this comparison.…”

“…We compare the resulting formula we compare with the 42 experimental points (see Ref. [21]) with β ≤ 0.056, having the same other kinematic variables as in sections III and IV. We obtain the description with χ 2 = 97 andᾱ S = 0.0549.…”