We present the results of measurements of two-particle angular correlations between trigger particles reconstructed in the ALICE Forward Muon Spectrometer ($-4.0 < \eta < -2.5$) and associated particles reconstructed in the central barrel detectors ($|\eta| < 1.0$) in p--Pb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. At low transverse momentum ($p_{ \mathrm{ T}}$), the reconstructed trigger particles mainly originate from weak decays of primary pions and kaons, whereas at high $p_{ \mathrm{ T}}$, they originate mainly from the decay of heavy-flavor particles. The ridge structure elongated in the $\eta$-direction, discovered recently in p--Pb collisions, is found to persist to the pseudorapidity ranges studied here. The second-order Fourier coefficients of muons are extracted after subtracting the correlations obtained in low-multiplicity events from those in high-multiplicity events. The ratio of coefficients in the Pb-going and p-going directions is presented as a function of $p_{ \mathrm{ T}}$, and the coefficients are observed to have a similar $p_{ \mathrm{ T}}$ dependence in both directions with the Pb-going coefficients larger by 16$\pm$6\%. The results are compared with calculations from a multi-phase transport model.
Categories: nucl-ex hep-ex