We present a new generic framework which enables exact and fast evaluation of all multi-particle azimuthal correlations. The framework can be readily used along with a correction framework for systematic biases in anisotropic flow analyses due to various detector inefficiencies. A new recursive algorithm has been developed for higher order correlators for the cases where their direct implementation is not feasible. We propose and discuss new azimuthal observables for anisotropic flow analyses which can be measured for the first time with our new framework. The effect of finite detector granularity on multi-particle correlations is quantified and discussed in detail. We point out the existence of a systematic bias in traditional differential flow analyses which stems solely from the applied selection criteria on particles used in the analyses, and is also present in the ideal case when only flow correlations are present. Finally, we extend the applicability of our generic framework to the case of differential multi-particle correlations. PACS numbers: 25.75.Ld, 25.75.Gz, 05.70.Fh arXiv:1312.3572v2 [nucl-ex] 20 Dec 2013 p.d.f. of M particles for an event with multiplicity M was utilized in flow analyses for the first time. On the other hand, the very first experimental attempt to go beyond two-particle azimuthal correlations [4] date back to Bevalac work published in [5]. In that paper, a quantitative description of collectivity was attempted by generalizing the observable for two-particle correlations, namely the smaller angle between the transverse momenta of two produced particles, into the geometric mean of n (n > 2) azimuthal separations within the n-particle multiplet. However, it was realized immediately that the net contribution of low-order few-particle correlations is cumulative if one increases the number of particles in such multiplets, which triggered the demand for more sophisticated techniques that would instead suppress systematically such contributions for increasingly large multiplets [5].This was pursued further in a series of papers on multi-particle correlations and cumulants by Borghini et al (for a summary of the mathematical and statistical properties of cumulants we refer the reader to [6]). In the first paper of the series [7], Borghini et al defined cumulants in the context of flow analyses in terms of the moments of the distribution of the Q-vector amplitude [1,2,8]. As a landmark of their approach, the authors have introduced a formalism of generating functions accompanied with interpolation methods in the complex plane as the simplest and fastest way to calculate cumulants from experimental data. The formalism of generating functions is particularly robust against biases stemming from non-uniform detector acceptance, which is frequently the dominant systematic bias in anisotropic flow analyses. However, there were some serious drawbacks, which were recognized and discussed already by the authors in the original paper. Most notably, both two-and multi-particle cumulants were plagued ...

The production of (anti-)deuteron and (anti-) 3 He nuclei in Pb-Pb collisions at √ s NN = 2.76 TeV has been studied using the ALICE detector at the LHC. The spectra exhibit a significant hardening with increasing centrality. Combined blast-wave fits of several particles support the interpretation that this behavior is caused by an increase of radial flow. The integrated particle yields are discussed in the context of coalescence and thermal-statistical model expectations. The particle ratios, 3 He /d and 3 He /p, in Pb-Pb collisions are found to be in agreement with a common chemical freeze-out temperature of T chem ≈ 156 MeV. These ratios do not vary with centrality which is in agreement with the thermal-statistical model. In a coalescence approach, it excludes models in which nucleus production is proportional to the particle multiplicity and favors those in which it is proportional to the particle density instead. In addition, the observation of 31 anti-tritons in Pb-Pb collisions is reported. For comparison, the deuteron spectrum in pp collisions at √ s = 7 TeV is also presented. While the p/π ratio is similar in pp and Pb-Pb collisions, the d/p ratio in pp collisions is found to be lower by a factor of 2.2 than in Pb-Pb collisions.