CERN Accelerating science

Invariant mass of (\he,\pim) (left) and (\antihe,\pip) (right) for events with 10--50\% centrality in the pair 2~$\leq$~\pt~$<$~10~\gmom\ interval. The data points are shown as full circle, while the squares represent the background distribution as described in the text. The curve represents the function used to perform the fit and used to evaluate the background and the raw signal.

Invariant mass of (\he,\pim) (left) and (\antihe,\pip) (right) for events with 10--50\% centrality in the pair 2~$\leq$~\pt~$<$~10~\gmom\ interval. The data points are shown as full circle, while the squares represent the background distribution as described in the text. The curve represents the function used to perform the fit and used to evaluate the background and the raw signal.

Left: Transverse momentum spectra multiplied by the B.R. of the \hyp~$\rightarrow$~\he~+~\pim\ decay for \hyp\ (full circle) and \antihyp\ (squares) for the most central (0--10\%) \PbPb\ collisions at \s\ = 2.76~TeV for $|y| <$ 0.5. Symbols are displaced for better visibility. Right: \antihyp\ to \hyp\ ratio as a function of \pt. In both panels statistical uncertainties are represented by bars and systematic uncertainties are represented by open boxes.

Left: Transverse momentum spectra multiplied by the B.R. of the \hyp~$\rightarrow$~\he~+~\pim\ decay for \hyp\ (full circle) and \antihyp\ (squares) for the most central (0--10\%) \PbPb\ collisions at \s\ = 2.76~TeV for $|y| <$ 0.5. Symbols are displaced for better visibility. Right: \antihyp\ to \hyp\ ratio as a function of \pt. In both panels statistical uncertainties are represented by bars and systematic uncertainties are represented by open boxes.

Measured d$N$/d(\ct) distribution and an exponential fit used to determine the lifetime. The bars and boxes are the statistical and systematic uncertainties, respectively.

\hyp\ lifetime ($\tau$) measured by in this analysis (red diamond) compared with published results. The band represents the world average of \hyp\ lifetime measurements $\left(\tau = 215^{+18}_{-16}\right)$ ps, while the dashed line represent the lifetime of $\Lambda$ as reported by the Particle Data Group \cite{Agashe:2014kda}.

Yield times branching ratios as a function of branching ratio (\dndy\ $\times \mathrm{B.R.}$ vs $B.R$). The horizontal line is the measured value and the band represents statistical and systematic uncertainties added in quadrature. Lines are different theoretical expectations as explained in the text.

The ratios \hyp/\he\ and \antihyp/\antihe\ determined by the present analysis (full circles) for matter and anti-matter compared with STAR results (squares) \cite{Abelev:2010sci} and theoretical predictions (lines) \cite{Andronic:2011thermal, petran:2013therm, Cleymans:2011pe, pal:2013hyp} as described in the legend.

Left: $B_2$ as a function of \pt\ /A for d (full circle) \cite{Abbas:2014nuclei}, \he\ (empty circle) \cite{Abbas:2014nuclei}, and \hyp\ (full squares). The $B_2^{(\mathrm{d},^{3}_{\Lambda}\mathrm{H})}$ and $B_2^{(\mathrm{d}, ^{3}\mathrm{He})}$ were evaluated as explained in the text. k$_1 = \frac{m_\mathrm{d}^2}{m_{^{3}\mathrm{He}}m_{\mathrm{p}}}$, and k$_2 = \frac{m_\mathrm{d}^2 m_{\Lambda}}{m_{\mathrm{p}}^2 m_{^{3}_{\Lambda}\mathrm H}}$. Right: $S_{3}$ ratio measured in this analysis compared with previous experimental results (E864 \cite{Armstrong:2002xh} and STAR \cite{Abelev:2010sci} (triangle and star, respectively)) and different theoretical models as indicated in the legend.

Left: $B_2$ as a function of \pt\ /A for d (full circle) \cite{Abbas:2014nuclei}, \he\ (empty circle) \cite{Abbas:2014nuclei}, and \hyp\ (full squares). The $B_2^{(\mathrm{d},^{3}_{\Lambda}\mathrm{H})}$ and $B_2^{(\mathrm{d}, ^{3}\mathrm{He})}$ were evaluated as explained in the text. k$_1 = \frac{m_\mathrm{d}^2}{m_{^{3}\mathrm{He}}m_{\mathrm{p}}}$, and k$_2 = \frac{m_\mathrm{d}^2 m_{\Lambda}}{m_{\mathrm{p}}^2 m_{^{3}_{\Lambda}\mathrm H}}$. Right: $S_{3}$ ratio measured in this analysis compared with previous experimental results (E864 \cite{Armstrong:2002xh} and STAR \cite{Abelev:2010sci} (triangle and star, respectively)) and different theoretical models as indicated in the legend.