11,134 research outputs found
Highlights from RHIC Spin Physics Program
The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory
delivers the world's highest energy polarized proton-proton collisions at a
center of mass energy up to 500 GeV and provides a unique opportunity to study
the quark and gluon spin structure of the proton and QCD dynamics at high
energy scale. RHIC has produced many exiting physics results in recent years.
The latest data from RHIC significantly constrain the gluon spin contribution
to the proton spin, and the parity violating single spin asymmetry are observed
for the first time in W production by both the PHENIX and STAR collaborations.
In this report, I present the latest results from the PHENIX and STAR
experiments, followed by a brief discussion of the future prospects of
transverse physics, particularly on the importance of the unique measurements
of Drell-Yan single spin asymmetry.Comment: 4 pages, MENU2010 proceeding
Higgs amplitude mode in massless Dirac fermion systems
The Higgs amplitude mode in superconductors is the condensed matter analogy
of Higgs bosons in particle physics. We investigate the time evolution of Higgs
amplitude mode in massless Dirac systems, induced by a weak quench of an
attractive interaction. We find that the Higgs amplitude mode in the
half-filling honeycomb lattice has a logarithmic decaying behaviour,
qualitatively different from the decay in the normal
superconductors. Our study is also extended to the doped cases in honeycomb
lattice. As for the 3D Dirac semimetal at half filling, we obtain an undamped
oscillation of the amplitude mode. Our finding is not only an important
supplement to the previous theoretical studies on normal fermion systems, but
also provide an experimental signature to characterize the superconductivity in
2D or 3D Dirac systems.Comment: 6 pages, 8 figure
Bounds for eigenvalue ratios of the Laplacian
For a bounded domain with a piecewise smooth boundary in an
-dimensional Euclidean space , we study eigenvalues of the
Dirichlet eigenvalue problem of the Laplacian. First we give a general
inequality for eigenvalues of the Laplacian. As an application, we study lower
order eigenvalues of the Laplacian and derive the ratios of lower order
eigenvalues of the Laplacian.Comment: 14 page
On QGP Formation in pp Collisions at 7 TeV
The possibility of QGP formation in central pp collisions at ultra-high
collision energy is discussed. Centrality-dependent \pt-spectra and
(pseudo)rapidity spectra of thermal photons (charged hadrons) from pp
collisions at 7 TeV are presented (addressed). Minimal-bias \pt-spectrum of
direct photons and charged hadrons is compared under the framework with and
without hydrodynamical evolution process.Comment: 4pages, 5figs, submitted to the Proceedings of the 22nd International
Conference on Ultra-relativistic Nucleus-Nucleus Collision (Quark Matter
2011), 23 - 28 May 2011, Annecy, Franc
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