Measurement of deuteron spectra and elliptic flow in Pb–Pb collisions at $\sqrt{{s}_{\mathrm{NN}}}$ = 2.76 TeV at the LHC

The transverse momentum ( ${p}_{T}$ ) spectra and elliptic flow coefficient ( ${v}_{2}$ ) of deuterons and anti-deuterons at mid-rapidity ( $|y|<0.5$ ) are measured with the ALICE detector at the LHC in Pb–Pb collisions at $\sqrt{{s}_{\mathrm{NN}}}$ = 2.76 TeV. The measurement of the ${p}_{T}$ spectra of (anti-)deuterons is done up to 8 GeV $/c$ in 0–10% centrality class and up to 6 GeV $/c$ in 10–20% and 20–40% centrality classes. The ${v}_{2}$ is measured in the 0.8 < ${p}_{T}$ $<\phantom{\rule{3.33333pt}{0ex}}$ 5 GeV $/c$ interval and in six different centrality intervals (0–5, 5–10, 10–20, 20–30, 30–40 and 40–50%) using the scalar product technique. Measured $\pi $ ${}^{±}$ , K ${}^{±}$ and p+ $\overline{p}$ transverse-momentum spectra and ${v}_{2}$ are used to predict the deuteron ${p}_{T}$ spectra and ${v}_{2}$ within the Blast-Wave model. The predictions are able to reproduce the ${v}_{2}$ coefficient in the measured ${p}_{T}$ range and the transverse-momentum spectra for ${p}_{T}$ > 1.8 GeV $/c$ within the experimental uncertainties. The measurement of the coalescence parameter ${B}_{2}$ is performed, showing a ${p}_{T}$ dependence in contrast with the simplest coalescence model, which fails to reproduce also the measured ${v}_{2}$ coefficient. In addition, the coalescence parameter ${B}_{2}$ and the elliptic flow coefficient in the 20–40% centrality interval are compared with the AMPT model which is able, in its version without string melting, to reproduce the measured ${v}_{2}$ ( ${p}_{T}$ ) and the ${B}_{2}$ ( ${p}_{T}$ ) trend.