Production of K$^{0}_{\rm S}$, $\Lambda (\overline{\Lambda})$, $\Xi^{\pm}$ and $\Omega^{\pm}$ in jets and underlying events in pp and p-Pb collisions with ALICE

Recent ALICE results on the yield of (multi-)strange particles in pp and p--Pb collisions reveal the possibility that similar strange quark production mechanisms could be present in all collision systems.
The $p_{\rm T}$-dependent baryon-to-meson yield ratio in hadronic and nuclear collisions is sensitive to the collective expansion of the system, the partonic recombination into hadrons, the jet fragmentation and hadronization.

In this contribution, we explore the connection between (multi-)strange hadron yields enhancement and jet production via the measurement of the $p_{\rm T}$-differential spectrum of strange and multi-strange particles (${\rm K}_{\rm S}^{0}$,  $\Lambda$ ($\overline{\Lambda}$), $\Xi^{\pm}$ and $\Omega^{\pm}$) within jets and in the underlying event, in pp collisions at $\sqrt{s}=13$~TeV and p--Pb collisions at $\sqrt{s_{\rm NN}}=5.02$~TeV, respectively.

 

Submitted to: JHEP
e-Print: arXiv:2211.08936 | PDF | inSPIRE
CERN-EP-2022-218

Figure 1

Invariant mass distribution for $\kzero$, $\lmb$, $\X$, and $\Om$ in different $\pT$ intervals in MB \pPb collisions at \fivenn The candidates are reconstructed in $|\eta|<0.75$. The grey areas are used to determine the background (red dashed lines), see text for details.

Figure 2

Strange particle reconstruction efficiency in \pp collisions at \thirteen (left) and in \pPb collisions at \fivenn (right) for two selections: inside the jet cone ($R({\rm par, jet}) < 0.4$) and for the inclusive case The vertical bars represent the statistical uncertainties.

Figure 3

Fraction of $\lmb$ yield removed due to the subtraction of feed-down contributions from charged and neutral $\Xi$ baryons decays in pp collisions at \thirteen (left) and \pPb collisions at \fivenn (right) The vertical bars represent the statistical uncertainties.

Figure 4

$\pT$-differential density, $\dd\rho/\dd\pT$, of $\kzero$ (top left panel), $\lmb$ (top right panel), $\Xi$ (bottom left panel), and $\Omega$ (bottom right panel) in pp collisions at \thirteen The spectra of JE particles (red triangles), associated with hard scatterings, are compared with that of JC (green squares) and UE (blue open circles) selections The results from inclusive measurements (black closed circles) are presented as well The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure 5

$\pT$-dependent strange baryon-to-meson (top) and baryon-to-baryon (bottom) yield ratios in pp collisions at \thirteen For each case, the results of JE particles (red triangles) are compared with that of inclusive (black closed circles) and UE (blue open circles) particles The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure 6

$\pT$-differential density distributions for inclusive (left) and within jets (right) $\kzero$ (black closed circles), $\lmb$ (red open circles), $\Xi$ (blue squares), and $\Omega$ (green inverted triangles) in \pp collisions at \thirteen The spectra in data are compared with \Pyeight CR-BLC simulations Three modes, labeled as mode $0$ (solid line), $2$ (dashed line), and $3$ (dash-dotted line) are adopted in the simulations The \Pdratio ratios are shown in the four bottom panels where the spread of the three \Pyeight CR-BLC implementation modes are presented as bands For clarity, some of the spectra were scaled with the factors indicated in the legends The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure 7

$\pT$-dependent strange baryon-to-meson (top) and baryon-to-baryon (bottom) ratios in pp collisions at \thirteen For each case, the results of JE (red triangles) and inclusive (black closed circles) particles are compared with \Pyeight CR-BLC simulations The bands correspond to the combination of simulations, where the spread of the three different CR-BLC implementation modes The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure 8

$\pT$-differential density, $\dd\rho/\dd\pT$, of $\kzero$ (top left panel), $\lmb$ (top right panel), $\Xi$ (bottom left panel), and $\Omega$ (bottom right panel) in \pPb collisions at \fivenn The spectra of JE particles (red triangles), associated with hard scatterings, are compared with that of JC (green squares) and UE (blue open circles) selections The results from inclusive measurements (black closed circles) are presented as well The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure 9

$\pT$-dependent strange baryon-to-meson (top) and baryon-to-baryon (bottom) ratios for particles produced within jets in \pPb collisions at \fivenn For each case, the results for different event multiplicity classes are compared with that in pp collisions at \thirteen The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes See the text for details.

Figure A.1

$\pT$-dependent $\Xi$/$\lmb$ (left panel) and $\Om$/$\lmb$ (right panel) ratios in pp collisions at \thirteen For each case, the results of JE particles (red inverted-triangle) are compared with that of inclusive (black closed circles) The corresponding colour-rope predictions  implemented in the \Pyeight event generator  are compared to data as well.

Figure A.2

$\pT$-differential density, $\dd\rho/\dd\pT$, of $\kzero$ (left panel), $\lmb$ (middle panel) and $\Xi$ (right panel) for the \cent{0}{10} event multiplicity class in \pPb collisions at \fivenn The spectra of JE particles (red inverted-triangle), associated with hard scatterings, are compared with that of JC (green squares) and UE (blue open circles) selections The results from inclusive measurements (black closed circles) are presented as well The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure A.3

$\pT$-differential density, $\dd\rho/\dd\pT$, of $\kzero$ (left panel), $\lmb$ (middle panel) and $\Xi$ (right panel) for the \cent{10}{40} event multiplicity class in \pPb collisions at \fivenn The spectra of JE particles (red inverted-triangle), associated with hard scatterings, are compared with that of JC (green squares) and UE (blue open circles) selections The results from inclusive measurements (black closed circles) are presented as well The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure A.4

$\pT$-differential density, $\dd\rho/\dd\pT$, of $\kzero$ (left panel), $\lmb$ (middle panel) and $\Xi$ (right panel) for the \cent{40}{100} event multiplicity class in \pPb collisions at \fivenn The spectra of JE particles (red inverted-triangle), associated with hard scatterings, are compared with that of JC (green squares) and UE (blue open circles) selections The results from inclusive measurements (black closed circles) are presented as well The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure A.5

$\pT$-dependent $\lmb$/$\kzero$ ratio for \cent{0}{10} (left panel), \cent{10}{40} (middle panel) and \cent{40}{100} (right panel) event multiplicity classes For each case, the results of JE particles (red inverted-triangle) are compared with that of inclusive (black closed circles) and UE (blue open circles) particles The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure A.6

$\pT$-dependent $\Xi$/$\kzero$ ratio for \cent{0}{10} (left panel), \cent{10}{40} (middle panel) and \cent{40}{100} (right panel) event multiplicity classes For each case, the results of JE particles (red inverted-triangle) are compared with that of inclusive (black closed circles) and UE (blue open circles) particles The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.

Figure A.7

$\pT$-dependent $\Xi$/$\lmb$ ratio for \cent{0}{10} (left panel), \cent{10}{40} (middle panel) and \cent{40}{100} (right panel) event multiplicity classes For each case, the results of JE particles (red inverted-triangle) are compared with that of inclusive (black closed circles) and UE (blue open circles) particles The statistical uncertainties are represented by the vertical error bars and the systematic uncertainties by the boxes.