The production yields of antideuterons and antiprotons are measured in pp collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV, as a function of transverse momentum ($p_{\rm T}$) and rapidity ($y$), for the first time up to $|y|= 0.7$. The measured spectra are used to study the $p_{\rm T}$ and rapidity dependence of the coalescence parameter $B_2$, which quantifies the coalescence probability of antideuterons. The $p_{\rm T}$ and rapidity dependence of the obtained $B_2$ is extrapolated for $p_{\rm T}> 1.7$ GeV/$c$ and $|y|>0.7$ using the phenomenological antideuteron production model implemented in PYTHIA 8.3 as well as a baryon coalescence afterburner model based on EPOS 3. Such measurements are of interest to the astrophysics community, since they can be used for the calculation of the flux of antinuclei from cosmic rays, in combination with coalescence models.
Submitted to: PLB
e-Print: arXiv:2407.10527 | PDF | inSPIRE
CERN-EP-2024-187
Figure group
Figure 1
Antiproton (left panel) and antideuteron (right panel) $p_{\rm T}$-differential yields for different rapidity intervals, in MB events. Statistical and systematic uncertainties are represented by vertical bars and boxes, respectively. The statistical uncertainties are smaller than the size of the markers in the reported scale and, hence, not visible. The dash-dotted lines represent the fit of the spectra executed with a Lévy-Tsallis function. |   |
Figure 2
Integrated yields of antiprotons (left) and antideuterons (right) as a function of rapidity, compared with the corresponding predictions of three models (see text for details). Statistical and systematic uncertainties are represented by vertical bars and boxes, respectively. The statistical uncertainties are smaller than the size of the markers in the reported scale and, hence, not visible. In the insets of the figures, a zoom in the low-rapidity region is displayed. The integrated yields estimated by models are normalized to the measured ones, see text for details. |   |
Figure 3
Coalescence parameter $B_2$ as a function of the transverse momentum per nucleon for different rapidity intervals. Data are compared to model predictions from PYTHIA 8.3 (left panel) and from a coalescence model used as afterburner of EPOS 3 (right panel), shown as colored lines. Statistical and systematic uncertainties on the data points are represented by vertical bars and boxes, respectively. The statistical uncertainties of the data points are smaller than the size of the markers in the reported scale and, hence, not visible. |   |
Figure 4
Coalescence parameter $B_2$ as a function of rapidity, for fixed transverse momentum per nucleon values. Statistical and systematic uncertainties on the data points are represented by vertical bars and boxes, respectively. The statistical uncertainties are smaller than the size of the markers in the reported scale and, hence, not visible. Bands show the model predictions from PYTHIA 8.3 (left panel) and from a coalescence model used as afterburner of EPOS 3 (right panel), the width reflecting the statistical uncertainties. |   |