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Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < p T,assoc < p T,trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p T bins, and the widths show no significant evolution with event multiplicity or p T . These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge.This Letter presents results extracted from two-particle correlation measurements in p-Pb collisions at √ s NN = 5.02 TeV, recorded with the ALICE detector [39] at the Large Hadron Collider (LHC). The correlations are measured over two units of 0370-2693/ √ s NN = 5.02 TeV proton-lead collisions with the ATLAS detector, arXiv:1212.5198 [hep-ex], 2012.

A good understanding of the transverse momentum () spectra is pivotal in the study of QCD matter created during the heavy-ion collision. Considering the difference in the underlying particle production mechanism, spectra can be divided into two distinct regions. Low-region corresponds to particle produced in soft-processes whereas particles produced in hard processes dominate the high-regime of the spectra. We will discuss a unified formalism to explain both low as well as high-region of the transverse momentum spectra in a consistent manner. This unified formalism is based on the generalisation of non-extensive statistical mechanics using the Pearson distribution. This generalised formalism also gives a strong insight into the study of elliptic flow in heavy-ion collision. Content of this proceeding is primarily based on the work [1].

Measurements of cross sections of inelastic and diffractive processes in proton–proton collisions at LHC energies were carried out with the ALICE detector. The fractions of diffractive processes in inelastic collisions were determined from a study of gaps in charged particle pseudorapidity distributions: for single diffraction (diffractive mass MX<200 GeV/c2) , and , respectively at centre-of-mass energies ; for double diffraction (for a pseudorapidity gap Δη>3) σDD/σINEL=0.11±0.03,0.12±0.05, and , respectively at . To measure the inelastic cross section, beam properties were determined with van der Meer scans, and, using a simulation of diffraction adjusted to data, the following values were obtained:  mb at and at . The single- and double-diffractive cross sections were calculated combining relative rates of diffraction with inelastic cross sections. The results are compared to previous measurements at proton–antiproton and proton–proton colliders at lower energies, to measurements by other experiments at the LHC, and to theoretical models.

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