18,298 research outputs found
Some aspects of global Lambda polarization in heavy-ion collisions
Large orbital angular momentum can be generated in non-central heavy-ion
collisions, and part of it is expected to be converted into final particle's
polarization due to the spin-orbit coupling. Within the framework of A
Multi-Phase Transport (AMPT) model, we studied the vorticity-induced
polarization of hyperons at the midrapidity region in
Au-Au collisions at energies GeV. Our results show
that the global polarization decreases with the collisional energies and is
consistent with the recent STAR measurements. This behavior can be understood
by less asymmetry of participant matter in the midrapidity region due to faster
expansion of fireball at higher energies. As another evidence, we discuss how
much the angular momentum is deposited in different rapidity region. The result
supports our asymmetry argument.Comment: 6 pages, 4 figures, CPOD 2017 proceedin
Fast DGT Based Receivers for GFDM in Broadband Channels
Generalized frequency division multiplexing (GFDM) is a recent multicarrier
5G waveform candidate with flexibility of pulse shaping filters. However, the
flexibility of choosing a pulse shaping filter may result in inter carrier
interference (ICI) and inter symbol interference (ISI), which becomes more
severe in a broadband channel. In order to eliminate the ISI and ICI, based on
discrete Gabor transform (DGT), in this paper, a transmit GFDM signal is first
treated as an inverse DGT (IDGT), and then a frequency-domain DGT is formulated
to recover (as a receiver) the GFDM signal. Furthermore, to reduce the
complexity, a suboptimal frequency-domain DGT called local DGT (LDGT) is
developed. Some analyses are also given for the proposed DGT based receivers.Comment: 28 pages, 8 figure
Research on Relationship between Agricultural Non-point Source Pollution and Economic Growth in Xinjiang: Based on Kuznets Curve
How to improve capability in preventing regional agricultural non-point source pollution, how to reduce the damage on agricultural environment caused by too fast economic growth and how to further improve agricultural production environment have became urgent issues. In this paper, the output coefficient method is used to estimate the discharge of agricultural non-point source pollution load in Xinjiang and its EKC characteristics are further analyzed, based on Kuznets Curve, so as to do empirical research on relationship between husbandry, planting, rural living and ecomonic growth. The results show that: (1) The total nitrogen (TN) and total phosphorus (TP) of agricultural non-point source pollution in Xinjiang are from big to small respectively: animal husbandry> planting industry> rural life; the non-point source pollution of animal husbandry mainly comes from cattle and sheep, the non-point source pollution of planting industry mainly comes from wheat, corn and cotton, and the non-point source pollution of rural life mainly comes from the growing rural population; (2)The relationship between agricultural non-point source pollution and economic growth in Xinjiang is not only an inverted“U”type, but also an inverted“N”type,“U”type and linear type
Transition Form Factors in the PQCD approach
Under two different scenarios for the light scalar mesons, we investigate the
transition form factors of mesons decay into a scalar meson in the
perturbative QCD approach. In the large recoiling region, the form factors are
dominated by the short-distance dynamics and can be calculated using
perturbation theory. We adopt the dipole parametrization to recast the
dependence of the form factors. Since the decay constants defined by the scalar
current are large, our predictions on the form factors are much larger
than the transitions, especially in the second scenario. Contributions
from various light-cone distribution amplitudes (LCDAs) are elaborated and we
find that the twist-3 LCDAs provide more than a half contributions to the form
factors. The two terms of the twist-2 LCDAs give destructive contributions in
the first scenario while they give constructive contributions in the second
scenario. With the form factors, we also predict the decay width and branching
ratios of the semileptonic and decays. The
branching ratios of channels are found to have the order of
while those of have the order of . These
predictions can be tested by the future experiments.Comment: 20 pages, 31 figure
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