40 research outputs found
The TMDICE Monte Carlo shower program and algorithm for jet-fragmentation via coherent medium induced radiations and scatterings
Parton jets in the hot and dense medium of a Quark Gluon Plasma (QGP) can
undergo multiple processes of scatterings off medium particles as well as
processes of coherent medium induced radiations. A Monte-Carlo algorithm and
resulting program is presented that allows to obtain jets that were formed by
these two types of processes from an initial highly energetic quark or gluon.
The program accounts for the increase in the momentum components of
jet-particles transverse to the jet-axis due to processes of scattering as well
as medium induced radiations in addition to energy-loss due to the medium
induced radiations.Comment: 16 pages, 1 figures; author's email address:
[email protected]
In-medium transverse momentum broadening effects on di-jet observables
Heavy ion collisions at high energies can be used as an interesting way to
recreate and study the medium of the quark-gluon plasma (QGP). We particularly
investigate the jets produced in hard binary collisions and their interactions
with a tentative medium. These jets were obtained numerically from the
Monte-Carlo simulations of hard collisions using the KATIE-algorithm [1], where
parton momenta within the colliding nucleons were describe by means of
unintegrated parton distribution functions (uPDF). We evolved these jets within
a medium that contains both, transverse kicks (yielding a broadening in
momentum transvers to the jet-axis) as well as medium induced radiation within
the MINCAS-algorithm [2] following the works of [3,4]. We produce qualitative
results for the decorrelation of dijets. In particular, we study deviations
from a transverse momentum broadening that follows a Gaussian distribution.
[1] A. van Hameren, Comput.Phys.Commun. 224 (2018) 371-380 [2] K. Kutak, W.
P{\l}aczek, R. Straka, Eur.Phys.J. C79 (2019) no.4, 317 [3] J.-P. Blaizot, F.
Dominguez, E. Iancu, Y. Mehtar-Tani, JHEP 1301 (2013) 143 [4] J.-P. Blaizot, F.
Dominguez, E. Iancu, Y. Mehtar-Tani, JHEP 1406 (2014) 07
Transverse momentum broadening of medium-induced cascades in expanding media
In this work, we explore the features of gluonic cascades in static and
Bjorken expanding media by numerically solving the full BDIM evolution
equations in longitudinal momentum fraction and transverse momentum
using the Monte Carlo event generator MINCAS. Confirming the
scaling of the energy spectra at low-, discovered in earlier works, we use
this insight to compare the amount of broadening in static and expanding media.
We compare angular distributions for the in-cone radiation for different medium
profiles with the effective scaling laws and conclude that the out-of-cone
energy loss proceeds via the radiative break-up of hard fragments, followed by
an angular broadening of soft fragments. While the dilution of the medium due
to expansion significantly affects the broadening of the leading fragments, we
provide evidence that in the low- regime, which is responsible for most of
the gluon multiplicity in the cascade, the angular distributions are very
similar when comparing different medium profiles at an equivalent, effective
in-medium path length. This is mainly due to the fact that in this regime, the
broadening is dominated by multiple splittings. Finally, we discuss the impact
of our results on the phenomenological description of the out-of-cone radiation
and jet quenching.Comment: 21 pages, 6 figures, matches accepted in European Physical Journal
In-medium transverse momentum broadening effects on di-jet observables
Heavy ion collisions at high energies can be used as an interesting way to recreate and study the medium of the quark-gluon plasma (QGP). We particularly investigate the jets produced in hard binary collisions and their interactions with a tentative medium. These jets were obtained numerically from the Monte-Carlo simulations of hard collisions using the Katie-algorithm, where parton momenta within the colliding nucleons were describe by means of unintegrated parton distribution functions (uPDF). We evolved these jets within a medium that contains both, transverse kicks (yielding a broadening in momentum transvers to the jet-axis) as well as medium induced radiation within the Mincas-algorithm following the works. We produce qualitative results for the decorrelation of dijets. In particular, we study deviations from a transverse momentum broadening that follows a Gaussian distribution
A New Model for Jet Energy Loss in Heavy Ion Collisions
We present a new model for jet quenching from coherent radiation in a brick
medium. The jet energy loss is simulated as a perturbative final-state vacuum
parton shower followed by a medium-induced shower originating from elastic and
radiative collisions with the medium constituents. Coherency is achieved by
starting with trial gluons that act as field dressing of the initial jet
parton. These are formed according to a Gunion-Bertsch seed. The QCD version of
the LPM effect is attained by increasing the phase of the trial gluons through
elastic scatterings with the medium. Above a phase threshold, the trial gluons
will be realised and can produce coherent radiation themselves. The model has
been implemented in a Monte Carlo code and has been validated by successfully
reproducing the BDMPS-Z prediction for the energy spectrum. The realistic case
with minimal assumptions are also produced and shown. In particular, we show
the influence of various parameters on the energy spectrum and transverse
momentum distribution, such as the in-medium quark masses, the energy transfer
in the recoil process, and the phase accumulation criteria, especially for low
and intermediate energy gluons. Future studies will allow for the interface
with full simulations of the quark-gluon-plasma with hydrodynamic evolution,
such as vHLLE, along with subsequent hadronisation of the jet partons in order
to produce realistic distributions that can be directly compared to LHC and
RHIC data.Comment: Proceedings for Hard Probes 2023 (Aschaffenburg, Germany, 26-31 March
2023). 6 pages, 8 figure
Mammalian WDR12 is a novel member of the Pes1–Bop1 complex and is required for ribosome biogenesis and cell proliferation
Target genes of the protooncogene c-myc are implicated in cell cycle and growth control, yet the linkage of both is still unexplored. Here, we show that the products of the nucleolar target genes Pes1 and Bop1 form a stable complex with a novel member, WDR12 (PeBoW complex). Endogenous WDR12, a WD40 repeat protein, is crucial for processing of the 32S precursor ribosomal RNA (rRNA) and cell proliferation. Further, a conditionally expressed dominant-negative mutant of WDR12 also blocks rRNA processing and induces a reversible cell cycle arrest. Mutant WDR12 triggers accumulation of p53 in a p19ARF-independent manner in proliferating cells but not in quiescent cells. Interestingly, a potential homologous complex of Pes1–Bop1–WDR12 in yeast (Nop7p–Erb1p–Ytm1p) is involved in the control of ribosome biogenesis and S phase entry. In conclusion, the integrity of the PeBoW complex is required for ribosome biogenesis and cell proliferation in mammalian cells