著者
Avsar E Hatta Y Flensburg C Ollitrault J-Y Ueda T
出版者
IOP
雑誌
Journal of physics. G, Nuclear and particle physics (ISSN:09543899)
巻号頁・発行日
vol.38, no.12, pp.124053, 2011-11
被引用文献数
9 16

High-multiplicity proton–proton collisions at the LHC may exhibit collective phenomena such as elliptic flow. We study this issue using DIPSY, a brand-new Monte Carlo event generator which features almost-NLO BFKL dynamics and describes the transverse shape of the proton including all fluctuations. We predict the eccentricity of the collision as a function of the multiplicity and estimate the magnitude of elliptic flow. We suggest that flow can be signaled by a sign change in the four-particle azimuthal correlation.
著者
Umeda T Ohno H Kanaya K
出版者
IOP Publishing Ltd
雑誌
Journal of physics. G, Nuclear and particle physics (ISSN:09543899)
巻号頁・発行日
vol.35, no.10, pp.104157, 2008-10
被引用文献数
1 1

Dissociation temperatures of J/ψ, ψ' and χc states play key roles in the sequential J/ψ suppression scenario for high-energy heavy-ion collisions. We report on a study of charmonium dissociation temperatures in quenched lattice QCD. On anisotropic lattices, we first subtract the effects of the constant mode in finite temperature meson correlators, which have led to unphysical results in previous studies. We then extract ground and first exited state masses by diagonalizing correlation functions among different source and sink operators. To distinguish bound states from scattering states, we first compare the charmonium mass spectra under different spatial boundary conditions, and examine the shape and the volume dependence of their Bethe–Salpeter wavefunctions. From these studies, we found, so far, no sign of scattering states up to about 2.3Tc.
著者
Ohno H Umeda T Kanaya K WHOT-QCD Collaboration
出版者
IOP Publishing Ltd
雑誌
Journal of physics. G, Nuclear and particle physics (ISSN:09543899)
巻号頁・発行日
vol.36, no.6, pp.064027, 2009
被引用文献数
4

Dissociation of charmonia in hot QCD is studied on a quenched anisotropic lattice using standard plaquette gauge action and O(a) improved Wilson fermion action. Simulations are carried out at temperatures in the range 0.88 TC to 2.3 TC. We calculate effective masses and Bethe–Salpeter wavefunctions for the ground state (1S, 1P) and some excited states (2S, 2P) with variational analysis. To distinguish between bound states and scattering states, we apply two methods: first, we compare effective masses for charmonium correlation functions under different spatial boundary conditions. Because the scattering states are sensitive to the boundary conditions, finite volume effects are expected when a charmonium dissociates. Second, we study if the wavefunctions show a sign of scattering states which will be characterized by a broad wavefunction. We find no clear evidence of dissociation for the charmonium states up to 2.3 TC so far.