170 research outputs found
Effects of Minijets on Common Observables in Heavy-Ion Collisions with Uncommon Implications
In this brief review of the observable effects of minijets in heavy-ion
collisions the main points emphasized are that the quadruple moment
and the hadronic ( and ) spectra at low can both be
reproduced by minijet contributions to the recombination of thermal and shower
partons. Without using hydrodynamics the minijet approach does not trace the
evolution of the expanding system. The thermal distribution of the medium
partons at the time of hadronization is assumed, but rapid thermalization
initially is not required so as to allow minijets to leave their footprints on
the system in the final state. Azimuthal anisotropy due to minijets is directly
calculated in the momentum space without any fluid assumption relating the
spatial eccentricity to . There are no more parameters used, compared to
the hydro approach in fitting the data on and spectra. Thus both
approaches satisfy the sufficiency condition for a viable description of the
dynamical process involved.Comment: 15 pages, invited mini-review published in Int. J. Modern Physics E,
vol 2
Relating Meson and Baryon Fragmentation Functions by Shower-Parton Recombination
We relate the fragmentation functions of partons into mesons and baryons in
the framework of recombination of shower partons. The results are in reasonable
agreement with the data. The implication is that the meson and baryon
fragmentation functions are not independent when hadronization of the shower
partons are taken into account. The conclusion therefore closes a conceptual
gap in the system of fragmentation functions whose evolution has been
more extensively studied than their interrelationship.Comment: 10 pages in LaTex + 3 figures in ep
Proton enhancement at large p_T at LHC without structure in associated-particle distribution
The production of pions and protons in the range between 10 and 20
GeV/c for Pb+Pb collisions at LHC is studied in the recombination model. It is
shown that the dominant mechanism for hadronization is the recombination of
shower partons from neighboring jets when the jet density is high. Protons are
more copiously produced than pions in that range because the coalescing
partons can have lower momentum fractions, but no thermal partons are involved.
The proton-to-pion ratio can rise beyond 20. When such a high hadron is
used as a trigger particle, there will not be any associated particles that are
not in the background.Comment: Revised version with new material adde
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