525 research outputs found
Gluon contribution to open heavy-meson production in heavy-ion collisions
A sizable contribution to heavy quark production in high-energy hadronic and
nuclear collisions comes from heavy quark-antiquark pair production from gluon
splitting during the parton shower evolution. We investigate the effect of
gluon-medium interaction on open heavy flavor spectra in ultra-relativistic
heavy-ion collisions. The interaction of hard gluons and heavy quarks with the
hot QCD medium is simulated by utilizing a Langevin transport model that
simultaneously incorporates contributions from collisional and radiative
processes. It is found that while the gluon splitting channel has quite an
important contribution to the single meson production cross section, its
influence on the final heavy meson nuclear modification turns out to be quite
modest because the average lifetime of hard gluons is short before splitting
into heavy quark-antiquark pairs during the evolution and propagation of the
parton shower.Comment: 5 pages, 6 figure
Probing medium-induced jet splitting and energy loss in heavy-ion collisions
The nuclear modification of jet splitting in relativistic heavy-ion
collisions at RHIC and the LHC energies is studied based on the higher twist
formalism. Assuming coherent energy loss for the two splitted subjets, a
non-monotonic jet energy dependence is found for the nuclear modification of
jet splitting function: strongest modification at intermediate jet energies
whereas weaker modification for larger or smaller jet energies. Combined with
the smaller size and lower density of the QGP medium at RHIC than at the LHC,
this explains the CMS-STAR groomed jet puzzle -- strong nuclear modification of
the momentum sharing distribution at the LHC whereas no obvious
modification of the distribution at RHIC. In contrast, the observed
nuclear modification pattern of the groomed jet distribution cannot be
explained solely by independent energy loss of the two subjets. Our result may
be tested in future measurements of groomed jets with lower jet energies at the
LHC and larger jet energies at RHIC, for different angular separations between
the two subjets.Comment: 10 pages, 12 figure
Modeling of heavy-flavor pair correlations in Au-Au collisions at 200 A GeV at the BNL Relativistic Heavy Ion Collider
We study the nuclear modification of angular and momentum correlations
between heavy quark pairs in ultrarelativistic heavy-ion collisions. The
evolution of heavy quarks inside the thermalized medium is described via a
modified Langevin approach that incorporates both elastic and inelastic
interactions with the medium constituents. The spacetime evolution of the
fireball is obtained from a (2+1)-dimensional viscous hydrodynamics simulation.
The hadronization of heavy quarks is performed utilizing a hybrid model of
fragmentation and coalescence. Our results show that the nuclear modification
of the transverse momentum imbalance of D\bar{D} pairs reflects the total
energy loss experienced by the heavy quarks and may help us probe specific
regions of the medium. The angular correlation of heavy flavor pairs,
especially in the low to intermediate transverse momentum regime, is sensitive
to the detailed energy loss mechanism of heavy quarks inside the QGP.Comment: 10 pages, 9 figure
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