12,196 research outputs found
Bounds of incidences between points and algebraic curves
We prove new bounds on the number of incidences between points and higher
degree algebraic curves. The key ingredient is an improved initial bound, which
is valid for all fields. Then we apply the polynomial method to obtain global
bounds on and .Comment: 11 page
NLO Productions of and with a Global Extraction of the Jet Transport Parameter in Heavy Ion collisions
In this work, we pave the way to calculate the productions of and
mesons at large in p+p and A+A collisions at the RHIC and
the LHC. The meson fragmentation functions (FFs) in vacuum at
next-to-leading order (NLO) are obtained by evolving NLO DGLAP evolution
equations with rescaled FFs at initial scale GeV from
a broken SU(3) model, and the FFs in vacuum are taken from AKK08
parametrization directly. Within the framework of the NLO pQCD improved parton
model, we make good descriptions of the experimental data on and
in p+p both at the RHIC and the LHC. With the higher-twist
approach to take into account the jet quenching effect by medium modified FFs,
the nuclear modification factors for meson and meson at
the RHIC and the LHC are presented with different sets of jet transport
coefficient . Then we make a global extraction of at the
RHIC and the LHC by confronting our model calculations with all available data
on 6 identified mesons: , , , , , and
. The minimum value of the total for productions of
these mesons gives the best value of for Au+Au
collisions with GeV at the RHIC, and for Pb+Pb collisions with TeV at the LHC
respectively, with the QGP spacetime evolution given by an event-by-event
viscous hydrodynamics model IEBE-VISHNU. With these global extracted values of
, the nuclear modification factors of , , ,
, , and in A+A collisions are presented, and
predictions of yield ratios such as and at
large in heavy-ion collisions at the RHIC and the LHC are provided.Comment: 9 pages, 13 figures, 1 tabl
Examining Virtual Tourism Community in China
This paper works to increase the body of knowledge on virtual community and incorporates a comparison using a different cultural environment β the context of China. We examine a virtual community of one of the largest travel companies in China - Mango. The Mango virtual community provides a platform for people to get to know each other, offer help and receive help when they have tourism related questions. The purpose of this study is to 1) investigate the usage pattern of a tourism virtual community, 2) apply social capital theory to virtual community, 3) validate prior virtual community research findings in a non-Western (China) tourism context 4) provide implications based on the analysis of user posting patterns. Our results also show collective action is generated by networks of relationships, reciprocity, trust, and social norms
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