180 research outputs found
Impact of Beauty and Charm H1-ZEUS Combined Measurements on PDFs and Determination of the Strong Coupling
In this QCD analysis, we investigate the impact of recent measurements of
heavy-flavor charm and beauty cross sections data sets on the simultaneous
determination of Parton Distribution Functions (PDFs) and the strong coupling,
. We perform three different fits based on Variable-Flavour
Number Scheme (VFNS) at the Leading Order (LO) and Next-to-Leading Order (NLO)
and choose the full HERA run I and II combined data as a new measurement of
inclusive Deep Inelastic Scattering (DIS) cross sections for our base data set.
We show that including charm and beauty cross sections data reduces the
uncertainty of gluon distribution and improves the fit quality up to 4.1\% from
leading order to next-to-leading order and up to 1.7\% for only NLO without and
with beauty and charm data contributions.Comment: 20 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1709.0840
Nuclear classical dynamics of H in intense laser field
In the first part of this paper, the different distinguishable pathways and
regions of the single and sequential double ionization are determined and
discussed. It is shown that there are two distinguishable pathways for the
single ionization and four distinct pathways for the sequential double
ionization. It is also shown that there are two and three different regions of
space which are related to the single and double ionization respectively. In
the second part of the paper, the time dependent Schr\"{o}dinger and Newton
equations are solved simultaneously for the electrons and the nuclei of H
respectively. The electrons and nuclei dynamics are separated on the base of
the adiabatic approximation. The soft-core potential is used to model the
electrostatic interaction between the electrons and the nuclei. A variety of
wavelengths (390 nm, 532 nm and 780 nm) and intensities (
and ) of the ultrashort intense laser
pulses with a sinus second order envelope function are used. The behaviour of
the time dependent classical nuclear dynamics in the absence and present of the
laser field are investigated and compared. In the absence of the laser field,
there are three distinct sections for the nuclear dynamics on the electronic
ground state energy curve. The bond hardening phenomenon does not appear in
this classical nuclear dynamics simulation.Comment: 16 pages, 7 figure
High-order harmonic generation by static coherent states method in single-electron atomic and molecular systems
We solve the time-dependent Schrodinger equation using the coherent states as basis sets for computing high harmonic generation (HHG) in a full-dimensional single-electron "realistic" system. We apply the static coherent states (SCS) method to investigate HHG in the hydrogen molecular ion induced by a linearly polarized laser field. We show that SCS gives reasonable agreement compared to the three dimensional unitary split-operator approach. Next, we study isolated attosecond pulse generation in H2+. To do so, we employ the well-known polarization gating technique, which combines two delayed counter-rotating circular laser pulses, and opens up a gate at the central portion of the superposed pulse. Our results suggest that the SCS method can be used for full-dimensional quantum simulation of higher dimensional systems such as the hydrogen molecule in the presence of an external laser field
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