168,595 research outputs found
Proton Production in d+Au Collisions and the Cronin Effect
Proton production in the intermediate p_T region in d+Au collisions is
studied in the parton recombination model. The recombination of soft and shower
partons is shown to be important in central collisions, but negligible in
peripheral collisions. It is found that the large nuclear modification factor
for proton production can be well reproduced by a calculation of the 3-quark
recombination process.Comment: 4 RevTeX pages + 2 eps figure
Solvable Lattice Gas Models with Three Phases
Phase boundaries in p-T and p-V diagrams are essential in material science
researches. Exact analytic knowledge about such phase boundaries are known so
far only in two-dimensional (2D) Ising-like models, and only for cases with two
phases. In the present paper we present several lattice gas models, some with
three phases. The phase boundaries are either analytically calculated or
exactly evaluated.Comment: 5 pages, 6 figure
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
Hadron Production in the Trans-fragmentation Region in Heavy-Ion Collisions
We study the production of hadrons in Au+Au collisions in the region
, which we refer to as the trans-fragmentation region (TFR), since
it corresponds roughly to , where , depending
on . We show how hadrons can be produced in that region when the
hadronization process is parton recombination. The inclusive -distributions
for proton and pion production are calculated with momentum degradation taken
into account. The results show that the proton yield is significantly higher
than that of the pions in the TFR. Without particle identification the existing
data cannot be used for comparison with our result on the ratio.
Without determination it is not feasible to relate the distribution
to the experimental distribution. Nevertheless, on theoretical grounds
we have shown why the production of hadrons in the TFR is not forbidden by
momentum conservation.Comment: 23 pages in LaTeX + 6 figures in ep
- …