Antiparticle to particle production ratios in hadron-hadron and $d$-Au collisions in the DPMJET-III Monte Carlo model

To understand baryon stopping we analyze new Relativistic Heavy Ion Collider and Fermilab data within the framework of the multichain Monte Carlo DPMJET-III. The present consideration is restricted to hadron-hadron and $d$-Au collisions, where the present version of the model can be trusted.

Figure 1

The diquark-conserving diagram for a nucleon-nucleus collision with two participants of the target nucleus.

Figure 2

The Glauber sea quark mechanism of baryon stopping (denoted as GSQBS) for a nucleon-nucleus collision with two participants of the target nucleus.

Figure 3

Standard DPM diagram for a nucleon-nucleon interaction with one additional soft secondary interaction induced by the unitarization procedure.

Figure 4

New DPM diagram for a nucleon-nucleon interaction with one additional soft secondary interaction induced by the unitarization procedure. We call this unitary sea quark mechanism for baryon-stopping USQBS [17].

Figure 5

$\sqrt{s}$ dependence of antiparticle-to-particle ratios in $p\text{−}p$ collisions at $y_{\mathrm{c}.\mathrm{m}.}=0$. Experimental data are from the BRAHMS Collaboration at RHIC [27], the ISR [39], and the NA27 Collaboration [40]. We compare DPMJET-III results with the experimental data.

Figure 6

Antiparticle-to-particle ratios, i.e., $\overline{p}/p$ (a), $K^{-}/K^{+}$ (b), and ${\pi }^{-}/{\pi }^{+}$ (c) in $p\text{−}p$ collisions at 200 GeV as function of the c.m. rapidity $y_{\mathrm{c}.\mathrm{m}.}$. We compare data from the BRAHMS Collaboration at RHIC [27] (including the systematic errors as given in the BRAHMS article) with the results obtained from DPMJET-III. We plot the $\overline{p}/p$ ratios for the full DPMJET model as well as for the model without the USQBS diagrams (“nostop”).

Figure 7

The $p/{\pi }^{+}$ particle production ratio as function of the transverse momentum in $\sqrt{s}=200$ GeV proton-proton collisions. We compare the ratio according to DPMJET-III with data from the STAR Collaboration [42].

Figure 8

Centrality dependence of charged antiparticle-to-particle ratios near midrapidity as measured by the PHOBOS Collaboration [25] in $d$-Au collisions at $\sqrt{s}=200$ GeV is compared to the DPMJET-III model.

Figure 9

${\pi }^{-}$ to ${\pi }^{+}$ (b) ratios in $d$-Au collisions at $\sqrt{s}=200$ GeV. We compare the data from the PHOBOS and the STAR Collaboration at RHIC [25, 43] to the results from the DPMJET-III model.

Figure 10

Anti-Λ-to-Λ ratio as function of the center-of-mass rapidity in minimum bias $d$-Au collisions at $\sqrt{s}=200$ GeV. We compare the experimental data from the STAR Collaboration at RHIC [26] to the results from the DPMJET-III model.

Figure 11

Net-Λ production as function of the center-of-mass rapidity in minimum bias $d$-Au collisions at $\sqrt{s}=200$ GeV. We compare the experimental data from he STAR Collaboration at RHIC [26] to the results from the DPMJET-III model.

Figure 12

Fragmentation into a baryon, the most important term in the fragmentation of a diquark.

Figure 13

Production of a antibaryon-baryon pair in the standard fragmentation of a diquark.

Figure 14

Nonstandard fragmentation of a diquark into a leading meson pair and a baryon.

Figure 15

The $A(\Lambda /\overline{\Lambda })$ asymmety. Plotted are the original DPMJET-III, the modified DPMJET-III, and the experimental data from the E791 Collaboration [9].

Figure 16

The $A(\Xi /\overline{\Xi })$ asymmety. Plotted are the original DPMJET-III, the modified DPMJET-III, and the experimental data from the E791 Collaboration [9].

Figure 17

The $A(\Omega /\overline{\Omega })$ asymmety. Plotted are the original DPMJET-III, the modified DPMJET-III, and the experimental data from the E791 Collaboration [9].

Figure 18

The net $\Xi \text{−}\overline{\Xi }$ contribution for charged an neutral hyperons for ${\pi }^{+}p$ and ${\pi }^{-}p$ scattering.

Figure 19

Rapidity distributions of produced $p,\overline{p},\Lambda ,\overline{\Lambda },\Xi$, and $\overline{\Xi }$ in proton-proton collisions at 158 GeV. We compare the rapidity distributions according to the modified DPMJET-III with experimental data from the NA49 Collaboration [10].