Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multiple scattering and $p_t$-broadening at RHIC energies   In ultrarelativistic heavy-ion collisions, in the 2 GeV$<p_\perp<$ 6 GeV
transverse momentum region, the soft and semi-hard multiple scattering of the
incoming nucleons in the nuclear medium results in the broadening of the
expected hadronic (e.g. pion) $p_\perp$ spectra relative to proton-proton
($pp$) collisions. Thus, higher transverse-momentum regions are populated than
in $pp$ collisions. In a perturbative QCD based calculation we include the
intrinsic transverse momentum ($k_\perp$) of the partons in the nucleon
(determined from $pp$ collisions), augmented by the extra broadening obtained
via a systematic analysis of proton-nucleus ($pA$) collisions in the energy
range 17$<\sqrt{s}<$ 39 AGeV. The original polynomial spectra are modified, and
a nearly exponential spectrum appears in the region 2$\lesssim p_\perp\lesssim
3.5$ GeV. At present RHIC energies ($\sqrt{s}=$130 AGeV), the slope of the
calculated spectra is reminiscent of that of fluid-dynamical descriptions, but
lacks any thermal origin. We determine and discuss the size of the
modifications originating in multiple scattering, which lead to this state of
affairs.

28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics