Measurement of prompt D-meson production in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV

The $p_{\rm T}$-differential production cross sections of the prompt charmed mesons $D^0$, $D^+$, $D^{*+}$ and $D_{\rm s}^{+}$ and their charge conjugate in the rapidity interval $-0.96 < y_{\rm cms} < 0.04$ were measured in p-Pb collisions at a centre-of-mass energy $\sqrt{s_{\rm NN}} = 5.02$ TeV with the ALICE detector at the LHC. The nuclear modification factor $R_{\rm pPb}$, quantifying the D-meson yield in p-Pb collisions relative to the yield in pp collisions scaled by the number of binary nucleon-nucleon collisions, is compatible within the 15-20% uncertainties with unity in the transverse momentum interval $1 < p_{\rm T} < 24$ GeV/$c$. No significant difference among the $R_{\rm pPb}$ of the four D-meson species is observed. The results are described within uncertainties by theoretical calculations that include initial-state effects. The measurement adds experimental evidence that the modification of the momentum spectrum of D mesons observed in Pb-Pb collisions with respect to pp collisions is due to strong final-state effects induced by hot partonic matter.

 

Phys. Rev. Lett. 113 (2014) 232301
HEP Data
e-Print: arXiv:arXiv:1405.3452 | PDF | inSPIRE
CERN-PH-EP-2014-090

Figure 1

$\pt$-differential inclusive production cross section of prompt $\Dzero$, $\Dplus$, $\Dstar$ and $\rm D^{+}_s$ mesons in $\pPb$ collisionsat $\sNN$=5.02 TeV. Statistical uncertainties (bars) and systematic uncertainties (boxes) are shown.

Figure 2

$\RpPb$ as a function of $\pt$ for prompt $\Dzero$, $\Dplus$, $\Dstar$ and $\rm D^{+}_s$ mesons in $\pPb$ collisions at $\sNN$=5.02 TeV. Statistical (bars), systematic (empty boxes), and normalization (full box) uncertainties are shown.

Figure 3

Average $\RpPb$ of prompt $\Dzero$, $\Dplus$and $\Dstar$ mesons as a function of $\pt$ compared to model calculations. Statistical (bars), systematic (empty boxes), and normalization (full box) uncertainties are shown.

Figure 4

Average $\RpPb$ of prompt $\Dzero$, $\Dplus$ and $\Dstar$ mesons as a function of $\pt$ compared to D-meson $\Raa$ in the 20% most central and in the 40-80% Pb-Pb collisions at $\sNN$=2.76 TeV. Statistical (bars), systematic (empty boxes), and normalization (full boxes) uncertainties are shown.