The production of Z$^0$ bosons at large rapidities in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV is reported. Z$^0$ candidates are reconstructed in the dimuon decay channel (${\rm Z}^0 \rightarrow \mu^+\mu^-$), based on muons selected with pseudo-rapidity $-4.0<\eta<-2.5$ and $p_{\rm T}>20$ GeV/$c$. The invariant yield and the nuclear modification factor, $R_{\rm AA}$, are presented as a function of rapidity and collision centrality. The value of $R_{\rm AA}$ for the 0-20% central Pb-Pb collisions is $0.67 \pm 0.11 \, \mbox{(stat.)} \, \pm 0.03 \, \mbox{(syst.)} \, \pm 0.06 \, \mbox{(corr. syst.)}$, exhibiting a deviation of $2.6 \sigma$ from unity. The results are well-described by calculations that include nuclear modifications of the parton distribution functions, while the predictions using vacuum PDFs deviate from data by $2.3\sigma$ in the 0-90% centrality class and by $3\sigma$ in the 0-20% central collisions.
Invariant yield of Z$^{0}$ production in 2.5 < y < 4.0 divided by the average nuclear overlap function in the 0-90% centrality class. The first uncertainty is statistical, the second is systematic.
Nuclear modification factor of Z$^{0}$ production in 2.5 < y < 4.0 in the 0-90% centrality class. The first uncertainty is statistical, the second is systematic.
Invariant yield of Z$^{0}$ production in 2.5 < y < 4.0 divided by the average nuclear overlap function as a function of rapidity in the 0-90% centrality class. The first uncertainty is statistical, the second is the uncorrelated systematic and the third is the correlated systematic.
Invariant differential yields of deuterons and anti-deuterons in pp collisions at $\sqrt{s}$ = 0.9, 2.76 and 7 TeV and the yields of tritons, $^{3}$He nuclei and their anti-nuclei at $\sqrt{s}$ = 7 TeV have been measured with the ALICE detector at the LHC. The measurements cover a wide transverse momentum ($p_{\text{T}}$) range in the rapidity interval $|y|<0.5$, extending both the energy and the $p_{\text{T}}$ reach of previous measurements up to 3 GeV/$c$ for $A=2$ and 6 GeV/$c$ for $A=3$. The coalescence parameters of (anti-)deuterons and $^{3}\overline{\text{He}}$ nuclei exhibit an increasing trend with $p_{\text{T}}$ and are found to be compatible with measurements in pA collisions at low $p_{\text{T}}$ and lower energies. The integrated yields decrease by a factor of about 1000 for each increase of the mass number with one (anti-)nucleon. Furthermore, the deuteron-to-proton ratio is reported as a function of the average charged particle multiplicity at different center-of-mass energies.
Invariant differential yield of deuterons and antideuterons in inelastic pp collisions at $\sqrt{s}$ = 0.9 TeV. The uncertainties of $_{-0.8}^{+2.2}$% due to the extrapolation to inelastic pp collisions are not included in the systematic uncertainties.
Invariant differential yield of deuterons and antideuterons in inelastic pp collisions at $\sqrt{s}$ = 2.76 TeV. The uncertainties of $_{-2.8}^{+5.2}$% due to the extrapolation to inelastic pp collisions are not included in the systematic uncertainties.
Invariant differential yield of deuterons and antideuterons in inelastic pp collisions at $\sqrt{s}$ = 7 TeV. The uncertainties of $_{-2.0}^{+5.0}$% due to the extrapolation to inelastic pp collisions are not included in the systematic uncertainties.
In ultrarelativistic heavy-ion collisions, the event-by-event variation of the elliptic flow $v_2$ reflects fluctuations in the shape of the initial state of the system. This allows to select events with the same centrality but different initial geometry. This selection technique, Event Shape Engineering, has been used in the analysis of charge-dependent two- and three-particle correlations in Pb-Pb collisions at $\sqrt{s_{_{\rm NN}}} =2.76$ TeV. The two-particle correlator $\langle \cos(\varphi_\alpha - \varphi_\beta) \rangle$, calculated for different combinations of charges $\alpha$ and $\beta$, is almost independent of $v_2$ (for a given centrality), while the three-particle correlator $\langle \cos(\varphi_\alpha + \varphi_\beta - 2\Psi_2) \rangle$ scales almost linearly both with the event $v_2$ and charged-particle pseudorapidity density. The charge dependence of the three-particle correlator is often interpreted as evidence for the Chiral Magnetic Effect (CME), a parity violating effect of the strong interaction. However, its measured dependence on $v_2$ points to a large non-CME contribution to the correlator. Comparing the results with Monte Carlo calculations including a magnetic field due to the spectators, the upper limit of the CME signal contribution to the three-particle correlator in the 10-50% centrality interval is found to be 26-33% at 95% confidence level.
$v_2\{EP\}$ with $|\Delta\eta| > 2.0$ as a function of centrality for unbiased events in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV.
$v_2\{EP\}$ with $|\Delta\eta| > 2.0$ as a function of centrality for shape selected events (0-10% $q_2$) in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV.
$v_2\{EP\}$ with $|\Delta\eta| > 2.0$ as a function of centrality for shape selected events (10-20% $q_2$) in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV.
We present the results of three-dimensional femtoscopic analyses for charged and neutral kaons recorded by ALICE in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV. Femtoscopy is used to measure the space-time characteristics of particle production from the effects of quantum statistics and final-state interactions in two-particle correlations. Kaon femtoscopy is an important supplement to that of pions because it allows one to distinguish between different model scenarios working equally well for pions. In particular, we compare the measured 3D kaon radii with a purely hydrodynamical calculation and a model where the hydrodynamic phase is followed by a hadronic rescattering stage. The former predicts an approximate transverse mass ($m_{\mathrm{T}}$) scaling of source radii obtained from pion and kaon correlations. This $m_{\mathrm{T}}$ scaling appears to be broken in our data, which indicates the importance of the hadronic rescattering phase at LHC energies. A $k_{\mathrm{T}}$ scaling of pion and kaon source radii is observed instead. The time of maximal emission of the system is estimated using the three-dimensional femtoscopic analysis for kaons. The measured emission time is larger than that of pions. Our observation is well supported by the hydrokinetic model predictions.
Out projection of raw 3D LCMS K+- K+- correlation function for 0.2 < kT < 0.4 GeV/c bin.
Side projection of raw 3D LCMS K+- K+- correlation function for 0.2 < kT < 0.4 GeV/c bin
Long projection of raw 3D LCMS K+- K+- correlation function for 0.2 < kT < 0.4 GeV/c bin
The correlations between event-by-event fluctuations of anisotropic flow harmonic amplitudes have been measured in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV with the ALICE detector at the LHC. The results are reported in terms of multiparticle correlation observables dubbed Symmetric Cumulants. These observables are robust against biases originating from nonflow effects. The centrality dependence of correlations between the higher order harmonics (the quadrangular $v_4$ and pentagonal $v_5$ flow) and the lower order harmonics (the elliptic $v_2$ and triangular $v_3$ flow) is presented. The transverse momentum dependence of correlations between $v_3$ and $v_2$ and between $v_4$ and $v_2$ is also reported. The results are compared to calculations from viscous hydrodynamics and A Multi-Phase Transport ({AMPT}) model calculations. The comparisons to viscous hydrodynamic models demonstrate that the different order harmonic correlations respond differently to the initial conditions and the temperature dependence of the ratio of shear viscosity to entropy density ($\eta/s$). A small average value of $\eta/s$ is favored independent of the specific choice of initial conditions in the models. The calculations with the AMPT initial conditions yield results closest to the measurements. Correlations between the magnitudes of $v_2$, $v_3$ and $v_4$ show moderate $p_{\rm T}$ dependence in mid-central collisions. Together with existing measurements of individual flow harmonics, the presented results provide further constraints on the initial conditions and the transport properties of the system produced in heavy-ion collisions.
Centrality dependence of observables SC(5,2) in Pb-Pb collisions at 2.76 TeV.
Centrality dependence of observables SC(5,3) in Pb-Pb collisions at 2.76 TeV.
Centrality dependence of observables SC(4,3) in Pb-Pb collisions at 2.76 TeV.
An invariant differential cross section measurement of inclusive $\pi^{0}$ and $\eta$ meson production at mid-rapidity in pp collisions at $\sqrt{s}=8$ TeV was carried out by the ALICE experiment at the LHC. The spectra of $\pi^{0}$ and $\eta$ mesons were measured in transverse momentum ranges of $0.3
Invariant differential cross section of $\pi^0$ produced in inelastic pp collisions at center of mass energy 8 TeV, the uncertainty of $\sigma_{MB}$ of 2.6% is not included in the systematic error.
Invariant differential cross section of $\eta$ produced in inelastic pp collisions at center of mass energy 8 TeV, the uncertainty of $\sigma_{MB}$ of 2.6% is not included in the systematic error.
Integrated yields of $\pi^{0}$ mesons produced in inelastic pp collisions at center of mass energies of 2.76 and 8 TeV. The uncertainty of $\sigma_{MB}$ of $^{+3.9\%}_{-6.4\%}(model)\pm2.0(lumi)$% for $\sqrt{s}=2.76$ TeV and $\pm2.3$% for 8 TeV is not included in the systematic error.
The transverse momentum ($p_{\rm T}$) 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 $\sqrt{s_{\rm NN}} = 2.76$ TeV. The measurement of the $p_{\rm T}$ spectra of (anti-)deuterons is done up to 8 GeV/$c$ in 0-10% centrality class and up to GeV/$c$ in 10-20% and 20-40% centrality classes. The $v_2$ is measured in the $0.8
Deuteron $p_{\mathrm T}$ spectra for $p_{\mathrm T} > $ 4.4 GeV/$c$. Low $p_{\mathrm T}$ points can be found here 'http://hepdata.cedar.ac.uk/view/ins1380491'
$\overline{\mathrm d}/ d $ vs $p_{\mathrm T}$ for $p_{\mathrm T} > $ 4.4 GeV/$c$. Low $p_{\mathrm T}$ points can be found here 'http://hepdata.cedar.ac.uk/view/ins1380491'
v2 of anti-deuterons and deuterons vs $p_{\mathrm T}$ for different centrality intervals
The measurement of azimuthal correlations of charged particles is presented for Pb-Pb collisions at $\sqrt{s_{\rm NN}}=$ 2.76 TeV and p-Pb collisions at $\sqrt{s_{\rm NN}}=$ 5.02 TeV with the ALICE detector at the CERN Large Hadron Collider. These correlations are measured for the second, third and fourth order flow vector in the pseudorapidity region $|\eta|<0.8$ as a function of centrality and transverse momentum $p_{\rm T}$ using two observables, to search for evidence of $p_{\rm T}$-dependent flow vector fluctuations. For Pb-Pb collisions at 2.76 TeV, the measurements indicate that $p_{\rm T}$-dependent fluctuations are only present for the second order flow vector. Similar results have been found for p-Pb collisions at 5.02 TeV. These measurements are compared to hydrodynamic model calculations with event-by-event geometry fluctuations in the initial state to constrain the initial conditions and transport properties of the matter created in Pb-Pb and p-Pb collisions.
$v_2\{2\}$ with $|\eta| > 0.0$ for centrality class 0-5\% in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV.
$v_2\{2\}$ with $|\eta| > 0.0$ for centrality class 5-10\% in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV.
$v_2\{2\}$ with $|\eta| > 0.0$ for centrality class 10-20\% in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV.
The azimuthal anisotropy coefficient $v_2$ of prompt D$^0$, D$^+$, D$^{*+}$ and D$_s^+$ mesons was measured in mid-central (30-50% centrality class) Pb-Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{\rm NN}} = 5.02$ TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at mid-rapidity, $|y|<0.8$, in the transverse momentum interval $1
$v_2$ vs. $p_{\rm T}$ of $D^0$ mesons in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$=5.02 TeV in the centrality class 30-50% in the rapidity interval |$y$|<0.8. The second (sys) error is the systematic uncertainty from the B feed-down contribution. The first (sys) error is the systematic uncertainty from the other sources.
$v_2$ vs. $p_{\rm T}$ of $D^+$ mesons in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$=5.02 TeV in the centrality class 30-50% in the rapidity interval |$y$|<0.8. The second (sys) error is the systematic uncertainty from the B feed-down contribution. The first (sys) error is the systematic uncertainty from the other sources.
$v_2$ vs. $p_{\rm T}$ of $D^{*+}$ mesons in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$=5.02 TeV in the centrality class 30-50% in the rapidity interval |$y$|<0.8. The second (sys) error is the systematic uncertainty from the B feed-down contribution. The first (sys) error is the systematic uncertainty from the other sources.
We present the first ever measurements of femtoscopic correlations between the K$^0_{\rm S}$ and K$^{\rm \pm}$ particles. The analysis was performed on the data from Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding via the $a_0(980)$ resonance. The extracted kaon source radius and correlation strength parameters for K$^0_{\rm S}$K$^{\rm -}$ are found to be equal within the experimental uncertainties to those for K$^0_{\rm S}$K$^{\rm +}$. Comparing the results of the present study with those from published identical-kaon femtoscopic studies by ALICE, mass and coupling parameters for the $a_0$ resonance are constrained. Our results are also compatible with the interpretation of the $a_0$ having a tetraquark structure over that of a diquark.
Raw K0s K+ correlation function for all kT bin
Raw K0s K+ correlation function for kT < 0.675 GeV/c bin
Raw K0s K+ correlation function for kT > 0.675 GeV/c bin
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