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Pseudorapidity distributions of charged particles as a function of mid and forward rapidity mutiplicities in pp collisions at $\sqrt{s}$ = 5.02, 7 and 13 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Eur.Phys.J.C 81 (2021) 630, 2021.
Inspire Record 1818157 DOI 10.17182/hepdata.106205

The multiplicity dependence of the pseudorapidity density of charged particles in proton-proton (pp) collisions at centre-of-mass energies $\sqrt{s}$ = 5.02, 7 and 13 TeV measured by ALICE is reported. The analysis relies on track segments measured in the midrapidity range ($|\eta| < 1.5$). Results are presented for inelastic events having at least one charged particle produced in the pseudorapidity interval $|\eta|<1$ ($\mathrm{INEL}_{>0}$). The multiplicity dependence of the pseudorapidy density of charged particles is measured with mid and forward rapidity multiplicity estimators, the latter being less affected by autocorrelations. A detailed comparison with predictions from the PYTHIA 8 and EPOS LHC event generators is also presented. Both generators provide a good description of the data.

6 data tables match query

Charged-particle pseudorapidity density for forward multiplicity classes as a function of $\eta$ in pp collisions at $\sqrt{s} = 5.02\,\mathrm{TeV}$. Statistical errors are generally insignificant.

Charged-particle pseudorapidity density for forward multiplicity classes as a function of $\eta$ in pp collisions at $\sqrt{s} = 7\,\mathrm{TeV}$. Statistical errors are generally insignificant.

Charged-particle pseudorapidity density for forward multiplicity classes as a function of $\eta$ in pp collisions at $\sqrt{s} = 13\,\mathrm{TeV}$. Statistical errors are generally insignificant.

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Kaon-proton strong interaction at low relative momentum via femtoscopy in Pb-Pb collisions at the LHC

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Lett.B 822 (2021) 136708, 2021.
Inspire Record 1863041 DOI 10.17182/hepdata.114016

In quantum scattering processes between two particles, aspects characterizing the strong and Coulomb forces can be observed in kinematic distributions of the particle pairs. The sensitivity to the interaction potential reaches a maximum at low relative momentum and vanishing distance between the two particles. Ultrarelativistic heavy-ion collisions at the LHC provide an abundant source of many hadron species and can be employed as a measurement method of scattering parameters that is complementary to scattering experiments. This study confirms that momentum correlations of particles produced in Pb-Pb collisions at the LHC provide an accurate measurement of kaon-proton scattering parameters at low relative momentum, allowing precise access to the $ {K}^{-} p\rightarrow {K}^{-} p$ process. This work also validates the femtoscopic measurement in ultrarelativistic heavy-ion collisions as an alternative to scattering experiments and a complementary tool to the study of exotic atoms with comparable precision. In this work, the first femtoscopic measurement of momentum correlations of ${K}^{-} p\ ({K}^{+}\overline{p})$ and ${K}^{+}p ({K}^{-}\overline{p})$ pairs in Pb-Pb collisions at centre-of-mass energy per nucleon pair of $\sqrt{s_{\rm NN}} = 5.02$ TeV registered by the ALICE experiment is reported. The components of the ${K}^{-} p$ complex scattering length are extracted and found to be $\Re f_0=-0.91\pm~{0.03}$(stat)$^{+0.17}_{-0.03}$(syst) and $\Im f_0 = 0.92\pm~{0.05}$(stat)$^{+0.12}_{-0.33}$(syst). The results are compared with chiral effective field theory predictions as well as with existing data from dedicated scattering and exotic kaonic atom experiments.

12 data tables match query

K p (opposite charge) correlation function for centrality 0-5% from Pb-Pb collisions at 5020 GeV

K p (same charge) correlation function for centrality 0-5% from Pb-Pb collisions at 5020 GeV

K p (opposite charge) correlation function for centrality 5-10% from Pb-Pb collisions at 5020 GeV

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Event-by-event multi-harmonic correlations of different flow amplitudes in Pb-Pb collisions at $\sqrt{s_{_{\rm NN}}}=2.76$ TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Rev.Lett. 127 (2021) 092302, 2021.
Inspire Record 1839720 DOI 10.17182/hepdata.110113

The event-by-event correlations between three flow amplitudes are measured for the first time in Pb--Pb collisions, using higher-order Symmetric Cumulants. We find that different three-harmonic correlations develop during the collective evolution of the medium, when compared with correlations that exist in the initial state. These new results cannot be interpreted in terms of previous lower-order flow measurements, since contributions from two-harmonic correlations are explicitly removed in the new observables. Comparison with Monte Carlo simulations provides new and independent constraints for the initial conditions and system properties of nuclear matter created in heavy-ion collisions.

6 data tables match query

Centrality dependence of ${\rm SC}(2,3,4)$ in Pb--Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$~TeV.

Centrality dependence of ${\rm SC}(2,3,5)$ in Pb--Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$~TeV.

Centrality dependence of ${\rm SC}(2,4,6)$ in Pb--Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$~TeV.

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$\Upsilon$ production and nuclear modification at forward rapidity in Pb-Pb collisions at $\mathbf{\sqrt{\textit{s}_{\textbf{NN}}}=5.02}$ TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Lett.B 822 (2021) 136579, 2021.
Inspire Record 1829413 DOI 10.17182/hepdata.114190

The production of $\Upsilon$ mesons in Pb-Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{\rm NN}}$ = 5 TeV is measured with the muon spectrometer of the ALICE detector at the LHC. The yields as well as the nuclear modification factors are determined in the forward rapidity region $2.5<y<4.0$, as a function of rapidity, transverse momentum and collision centrality. The results show that the production of the $\Upsilon$(1S) meson is suppressed by a factor of about three with respect to the production in proton-proton collisions. For the first time, a significant signal for the $\Upsilon$(2S) meson is observed at forward rapidity, indicating a suppression stronger by about a factor 2-3 with respect to the ground state. The measurements are compared with transport, hydrodynamic, comover and statistical hadronisation model calculations.

14 data tables match query

Rapidity-differential yield of $\Upsilon(1\mathrm{S}) \rightarrow \mu^{+}\mu^{-}$ divided by the average nuclear overlap function $\langle T_{\mathrm{AA}} \rangle$ for the 0–90% centrality interval ($\langle T_{\mathrm{AA}} \rangle$ = 6.28 $\pm$ 0.06 mb$^{-1}$).

Rapidity-differential yield of $\Upsilon(2\mathrm{S}) \rightarrow \mu^{+}\mu^{-}$ divided by the average nuclear overlap function $\langle T_{\mathrm{AA}} \rangle$ for the 0–90% centrality interval ($\langle T_{\mathrm{AA}} \rangle$ = 6.28 $\pm$ 0.06 mb$^{-1}$).

$p_{\mathrm{T}}$-differential yield of $\Upsilon(1\mathrm{S}) \rightarrow \mu^{+}\mu^{-}$ divided by the average nuclear overlap function $\langle T_{\mathrm{AA}} \rangle$ for the 0–90% centrality interval ($\langle T_{\mathrm{AA}} \rangle$ = 6.28 $\pm$ 0.06 mb$^{-1}$).

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Azimuthal correlations of prompt D mesons with charged particles in pp and p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Eur.Phys.J.C 80 (2020) 979, 2020.
Inspire Record 1762354 DOI 10.17182/hepdata.95121

The measurement of the azimuthal-correlation function of prompt D mesons with charged particles in pp collisions at $\sqrt{s}$ = 5.02 TeV and p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with the ALICE detector at the LHC is reported. The D$^{\rm 0}$, D$^{\rm +}$, and D$^{\rm *+}$ mesons, together with their charge conjugates, were reconstructed at midrapidity in the transverse momentum interval 3 < $p_{\rm T}$ < 24 GeV/c and correlated with charged particles having $p_{\rm T}$ > 0.3 GeV/c and pseudorapidity $|\eta| <$ 0.8. The properties of the correlation peaks appearing in the near- and away-side regions (for $\Delta \varphi \approx$ 0 and $\Delta \varphi \approx \pi$, respectively) were extracted via a fit to the azimuthal correlation functions. The shape of the correlation functions and the near- and away-side peak features are found to be consistent in pp and p-Pb collisions, showing no modifications due to nuclear effects within uncertainties. The results are compared with predictions from Monte Carlo simulations performed with the PYTHIA, POWHEG+PYTHIA, HERWIG, and EPOS 3 event generators.

51 data tables match query

Comparison of the azimuthal-correlation distributions of D mesons (average of D$^{0}$, D$^{+}$, D$^{*+}$) with $3 < p_{\rm T} < 5$ GeV/$c$ and charged particles with $p_{\rm T} > 0.3$ GeV/$c$, in pp collisions at $\sqrt{s} = 5.02$ TeV and p-Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV, after baseline subtraction. Rapidity range for the D mesons are $|y^{\rm D}_{\rm cms}| < 0.5$ in pp, $-0.96 < y^{\rm D}_{\rm cms} < 0.04$ in p-Pb. Correlations are integrated for $|\Delta\eta|=|\eta_{\rm ch}-\eta_{\rm D}| < 1$. The azimuthal-correlation distributions are reported in the range $0 < \Delta\varphi < \pi$.

Comparison of the azimuthal-correlation distributions of D mesons (average of D$^{0}$, D$^{+}$, D$^{*+}$) with $5 < p_{\rm T} < 8$ GeV/$c$ and charged particles with $p_{\rm T} > 0.3$ GeV/$c$, in pp collisions at $\sqrt{s} = 5.02$ TeV and p-Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV, after baseline subtraction. Rapidity range for the D mesons are $|y^{\rm D}_{\rm cms}| < 0.5$ in pp, $-0.96 < y^{\rm D}_{\rm cms} < 0.04$ in p-Pb. Correlations are integrated for $|\Delta\eta|=|\eta_{\rm ch}-\eta_{\rm D}| < 1$. The azimuthal-correlation distributions are reported in the range $0 < \Delta\varphi < \pi$.

Comparison of the azimuthal-correlation distributions of D mesons (average of D$^{0}$, D$^{+}$, D$^{*+}$) with $8 < p_{\rm T} < 16$ GeV/$c$ and charged particles with $p_{\rm T} > 0.3$ GeV/$c$, in pp collisions at $\sqrt{s} = 5.02$ TeV and p-Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV, after baseline subtraction. Rapidity range for the D mesons are $|y^{\rm D}_{\rm cms}| < 0.5$ in pp, $-0.96 < y^{\rm D}_{\rm cms} < 0.04$ in p-Pb. Correlations are integrated for $|\Delta\eta|=|\eta_{\rm ch}-\eta_{\rm D}| < 1$. The azimuthal-correlation distributions are reported in the range $0 < \Delta\varphi < \pi$.

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Higher harmonic non-linear flow modes of charged hadrons in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
JHEP 05 (2020) 085, 2020.
Inspire Record 1778342 DOI 10.17182/hepdata.94869

Anisotropic flow coefficients, $v_n$, non-linear flow mode coefficients, $\chi_{n,mk}$, and correlations among different symmetry planes, $\rho_{n,mk}$ are measured in Pb-Pb collisions at $\sqrt{s_\rm{NN}}=5.02$ TeV. Results obtained with multi-particle correlations are reported for the transverse momentum interval $0.2<p_\rm{T}<5.0$ GeV/$c$ within the pseudorapidity interval $0.4<|\eta|<0.8$ as a function of collision centrality. The $v_n$ coefficients and $\chi_{n,mk}$ and $\rho_{n,mk}$ are presented up to the ninth and seventh harmonic order, respectively. Calculations suggest that the correlations measured in different symmetry planes and the non-linear flow mode coefficients are dependent on the shear and bulk viscosity to entropy ratios of the medium created in heavy-ion collisions. The comparison between these measurements and those at lower energies and calculations from hydrodynamic models places strong constraints on the initial conditions and transport properties of the system.

23 data tables match query

Centrality dependence of flow harmonics from $v_2$ to $v_9$.

Centrality dependence of flow harmonics from $v_2$ to $v_9$.

Centrality dependence of flow harmonics from $v_2$ to $v_9$.

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Production of (anti-)$^3$He and (anti-)$^3$H in p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Rev.C 101 (2020) 044906, 2020.
Inspire Record 1762356 DOI 10.17182/hepdata.94416

The transverse momentum ($p_{\rm{T}}$) differential yields of (anti-)$^3$He and (anti-)$^3$H measured in p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV with ALICE at the Large Hadron Collider (LHC) are presented. The ratios of the $p_{\rm{T}}$-integrated yields of (anti-)$^3$He and (anti-)$^3$H to the proton yields are reported, as well as the $p_{\rm{T}}$ dependence of the coalescence parameters $B_3$ for (anti-)$^3$He and (anti-)$^3$H. For (anti-)$^3$He, the results obtained in four classes of the mean charged-particle multiplicity density are also discussed. These results are compared to predictions from a canonical statistical hadronization model and coalescence approaches. An upper limit on the total yield of $^4\bar{\mathrm{He}}$ is determined.

24 data tables match query

Transverse momentum spectra of (anti-)$^3\mathrm{He}$ measured in $\mathrm{INEL}>0$ p--Pb collisions at $\sqrt{s_\mathrm{NN}} = 5.02$

Transverse momentum spectra of (anti-)$^3\mathrm{H}$ measured in $\mathrm{INEL}>0$ p--Pb collisions at $\sqrt{s_\mathrm{NN}} = 5.02$

$^3\overline{\mathrm{He}} /\,^3\mathrm{He}$ ratio in $\mathrm{INEL}>0$ p--Pb collisions at $\sqrt{s_\mathrm{NN}} = 5.02$

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Measurement of the (anti-)$^{3}$He elliptic flow in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adhya, Souvik Priyam ; et al.
Phys.Lett.B 805 (2020) 135414, 2020.
Inspire Record 1760170 DOI 10.17182/hepdata.95240

The elliptic flow ($v_{2}$) of (anti-)$^{3}$He is measured in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV in the transverse-momentum ($p_{\rm{T}}$) range of 2-6 GeV/$c$ for the centrality classes 0-20%, 20-40%, and 40-60% using the event-plane method. This measurement is compared to that of pions, kaons, and protons at the same center-of-mass energy. A clear mass ordering is observed at low $p_{\rm{T}}$, as expected from relativistic hydrodynamics. The violation of the scaling of $v_{2}$ with the number of constituent quarks at low $p_{\rm{T}}$, already observed for identified hadrons and deuterons at LHC energies, is confirmed also for (anti-)$^{3}$He. The elliptic flow of (anti-)$^{3}$He is underestimated by the Blast-Wave model and overestimated by a simple coalescence approach based on nucleon scaling. The elliptic flow of (anti-)$^{3}$He measured in the centrality classes 0-20% and 20-40% is well described by a more sophisticated coalescence model where the phase-space distributions of protons and neutrons are generated using the iEBE-VISHNU hybrid model with AMPT initial conditions.

4 data tables match query

Event-plane resolution $R_{\Psi_{2}}$ of the second harmonic as a function of the collision centrality.

Elliptic flow ($v_{2}$) of (anti-)$^{3}$He measured in Pb-Pb collisions at \sqrt{s_{\mathrm{NN}}} = 5.02 TeV for the centrality classes 0--20$\%$, 20--40$\%$, and 40--60$\%$. The statistical uncertainties are shown as vertical bars, systematic uncertainties as boxes.

Elliptic flow ($v_{2}$) of (anti-)$^{3}$He measured in Pb-Pb collisions at \sqrt{s_{\mathrm{NN}}} = 5.02 TeV for the centrality classes 0--20$\%$, 20--40$\%$, and 40--60$\%$. The statistical uncertainties are shown as vertical bars, systematic uncertainties as boxes.

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Scattering studies with low-energy kaon-proton femtoscopy in proton-proton collisions at the LHC

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adhya, Souvik Priyam ; et al.
Phys.Rev.Lett. 124 (2020) 092301, 2020.
Inspire Record 1737592 DOI 10.17182/hepdata.93732

The study of the strength and behaviour of the antikaon-nucleon ($\mathrm{\overline{K}N}$) interaction constitutes one of the key focuses of the strangeness sector in low-energy Quantum Chromodynamics (QCD). In this letter a unique high-precision measurement of the strong interaction between kaons and protons, close and above the kinematic threshold, is presented. The femtoscopic measurements of the correlation function at low pair-frame relative momentum of (K$^+$ p $\oplus$ K$^-$ $\overline{\mathrm{p}}$) and (K$^-$ p $\oplus$ K$^+$ $\overline{\mathrm{p}}$) pairs measured in pp collisions at $\sqrt{s}$ = 5, 7 and 13 TeV are reported. A structure observed around a relative momentum of 58 MeV/$c$ in the measured correlation function of (K$^-$ p $\oplus$ K$^+$ $\overline{\mathrm{p}}$) with a significance of 4.4. $\sigma$ constitutes the first experimental evidence for the opening of the $(\mathrm{\overline{K}^0 n} \oplus \mathrm{K^0 \overline{n}})$ isospin breaking channel due to the mass difference between charged and neutral kaons. The measured correlation functions have been compared to J\"{u}lich and Kyoto models in addition to the Coulomb potential. The high-precision data at low relative momenta presented in this work prove femtoscopy to be a powerful complementary tool to scattering experiments and provide new constraints above the $\mathrm{\overline{K}N}$ threshold for low-energy QCD chiral models.

7 data tables match query

K-p correlation function in p-p collisions at $\sqrt{s}=5$ TeV.

K-p correlation function in p-p collisions at $\sqrt{s}=7$ TeV.

K-p correlation function in p-p collisions at $\sqrt{s}=13$ TeV.

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Longitudinal and azimuthal evolution of two-particle transverse momentum correlations in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Lett.B 804 (2020) 135375, 2020.
Inspire Record 1762340 DOI 10.17182/hepdata.93887

This paper presents the first measurements of the charge independent (CI) and charge dependent (CD) two-particle transverse momentum correlators $G_{2}^{\rm CI}$ and $G_{2}^{\rm CD}$ in Pb--Pb collisions at $\sqrt{s_{\text{NN}}} = 2.76\;\text{\TeVe}$ by the ALICE collaboration. The two-particle transverse momentum correlator $G_{2}$ was introduced as a measure of the momentum current transfer between neighbouring system cells. The correlators are measured as a function of pair separation in pseudorapidity ($\Delta \eta$) and azimuth ($\Delta \varphi$) and as a function of collision centrality. From peripheral to central collisions, the correlator $G_{2}^{\rm CI}$ exhibits a longitudinal broadening while undergoing a monotonic azimuthal narrowing. By contrast, $G_{2}^{\rm CD}$ exhibits a narrowing along both dimensions. These features are not reproduced by models such as HIJING and AMPT. However, the observed narrowing of the correlators from peripheral to central collisions is expected to result from the stronger transverse flow profiles produced in more central collisions and the longitudinal broadening is predicted to be sensitive to momentum currents and the shear viscosity per unit of entropy density $\eta/s$ of the matter produced in the collisions. The observed broadening is found to be consistent with the hypothesized lower bound of $\eta/s$ and is in qualitative agreement with values obtained from anisotropic flow measurements.

12 data tables match query

Two-particle transverse momentum correlation $G_{2}^{\rm CI}$ for central (0-5%) Pb--Pb collisions at $\sqrt{s_{\rm NN}}=2.76\;\text{TeV}$.

Two-particle transverse momentum correlation $G_{2}^{\rm CI}$ for semi-central (30-40%) Pb--Pb collisions at $\sqrt{s_{\rm NN}}=2.76\;\text{TeV}$.

Two-particle transverse momentum correlation $G_{2}^{\rm CI}$ for perippheral (70-80%) Pb--Pb collisions at $\sqrt{s_{\rm NN}}=2.76\;\text{TeV}$.

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