The
ALICE
collaboration
Acharya, Shreyasi
;
Adamova, Dagmar
;
Adhya, Souvik Priyam
;
*et al. *

Eur.Phys.J. C80 (2020) 167, 2020.

http://inspirehep.net/literature/1748157
Inspire Record
1748157
DOI
10.17182/hepdata.93535
https://doi.org/10.17182/hepdata.93535
The production rates and the transverse momentum distribution of strange hadrons at mid-rapidity ($\ |y\ | < 0.5$) are measured in proton-proton collisions at $\sqrt{s}$ = 13 TeV as a function of the charged particle multiplicity, using the ALICE detector at the LHC. It is found that the production rates of $\rm{K}^{0}_{S}$, $\Lambda$, $\Xi$, and $\Omega$ increase with the multiplicity faster than what is reported for inclusive charged particles. The increase is found to be more pronounced for hadrons with a larger strangeness content. Possible auto-correlations between the charged particles and the strange hadrons are evaluated by measuring the event-activity with charged particle multiplicity estimators covering different pseudorapidity regions. The yields of strange hadrons are found to depend only on the mid-rapidity multiplicity for charged particle multiplicity estimators selecting in the forward region, which turn out to be more directly related to the number of Multiple Parton Interactions. Several features of the data are reproduced qualitatively by general purpose QCD Monte Carlo models that take into account the effect of densely-packed QCD strings in high multiplicity collisions. However, none of the tested models reproduce the data quantitatively. This work corroborates and extends the ALICE findings on strangeness production in proton-proton collisions at 7 TeV.

59
data tables

The
ALICE
collaboration
Acharya, Shreyasi
;
Adamova, Dagmar
;
Adhya, Souvik Priyam
;
*et al. *

Phys.Rev.Lett. 124 (2020) 092301, 2020.

http://inspirehep.net/literature/1737592
Inspire Record
1737592
DOI
10.17182/hepdata.93732
https://doi.org/10.17182/hepdata.93732
The study of the strength and behavior of the antikaon-nucleon (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⊕K−p¯) and (K-p⊕K+p¯) pairs measured in pp collisions at 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⊕K+p¯) with a significance of 4.4σ constitutes the first experimental evidence for the opening of the (K¯0n⊕K0n¯) isospin breaking channel due to the mass difference between charged and neutral kaons. The measured correlation functions have been compared to Jülich 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 K¯N threshold for low-energy QCD chiral models.

7
data tables

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.

The
ALICE
collaboration
Acharya, Shreyasi
;
Adamova, Dagmar
;
Adhya, Souvik Priyam
;
*et al. *

2019.

http://inspirehep.net/literature/1735349
Inspire Record
1735349
DOI
10.17182/hepdata.90845
https://doi.org/10.17182/hepdata.90845
This work presents new constraints on the existence and the binding energy of a possible $\Lambda$-$\Lambda$ bound state, the H-dibaryon, derived from $\Lambda$-$\Lambda$ femtoscopic measurements by the ALICE collaboration. The results are obtained from a new measurement using the femtoscopy technique in pp collisions at $\sqrt{s}=13$ TeV and p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV, combined with previously published results from p-Pb collisions at $\sqrt{s}=7$ TeV. The $\Lambda$-$\Lambda$ scattering parameter space, spanned by the inverse scattering length $f_0^{-1}$ and the effective range $d_0$, is constrained by comparing the measured $\Lambda$-$\Lambda$ correlation function with calculations obtained within the Lednicky model. The data are compatible with hypernuclei results and lattice computations, both predicting a shallow attractive interaction, and permit to test different theoretical approaches describing the $\Lambda$-$\Lambda$ interaction. The region in the $(f_0^{-1},d_0)$ plane which would accommodate a $\Lambda$-$\Lambda$ bound state is substantially restricted compared to previous studies. The binding energy of the possible $\Lambda$-$\Lambda$ bound state is estimated within an effective-range expansion approach and is found to be $B_{\Lambda\Lambda}=3.2^{+1.6}_{-2.4}\mathrm{(stat)}^{+1.8}_{-1.0}\mathrm{(syst)}$ MeV.

8
data tables

Exclusion plot for the $\Lambda$-$\Lambda$ binding energy (statistical uncertainty).

Exclusion plot for the $\Lambda$-$\Lambda$ binding energy (total uncertainty).

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

The
ALICE
collaboration
Acharya, Shreyasi
;
Adamova, Dagmar
;
Adhya, Souvik Priyam
;
*et al. *

2019.

http://inspirehep.net/literature/1733689
Inspire Record
1733689
DOI
10.17182/hepdata.91239
https://doi.org/10.17182/hepdata.91239
The cross section of jets reconstructed from charged particles is measured in the transverse momentum range of $5<p_\mathrm{T}<100\ \mathrm{GeV}/c$ in pp collisions at the center-of-mass energy of $\sqrt{s} = 5.02\ \mathrm{TeV}$ with the ALICE detector. The jets are reconstructed using the anti-$k_\mathrm{T}$ algorithm with resolution parameters $R=0.2$, $0.3$, $0.4$, and $0.6$ in the pseudorapidity range $|\eta|< 0.9-R$. The charged jet cross sections are compared with the leading order (LO) and to next-to-leading order (NLO) perturbative Quantum ChromoDynamics (pQCD) calculations. It was found that the NLO calculations agree better with the measurements. The cross section ratios for different resolution parameters were also measured. These ratios increase from low $p_\mathrm{T}$ to high $p_\mathrm{T}$ and saturate at high $p_\mathrm{T}$, indicating that jet collimation is larger at high $p_\mathrm{T}$ than at low $p_\mathrm{T}$. These results provide a precision test of pQCD predictions and serve as a baseline for the measurement in Pb$-$Pb collisions at the same energy to quantify the effects of the hot and dense medium created in heavy-ion collisions at the LHC.

4
data tables

The
ALICE
collaboration
Acharya, Shreyasi
;
Adamova, Dagmar
;
Adhya, Souvik Priyam
;
*et al. *

2019.

http://inspirehep.net/literature/1723697
Inspire Record
1723697
DOI
10.17182/hepdata.90955
https://doi.org/10.17182/hepdata.90955
Measurements of anisotropic flow coefficients ($v_n$) and their cross-correlations using two- and multi-particle cumulant methods are reported in collisions of pp at $\sqrt{s} = 13$ TeV, p-Pb at $\sqrt{s_{_{\rm NN}}} = 5.02$ TeV, Xe-Xe at $\sqrt{s_{_{\rm NN}}} = 5.44$ TeV, and Pb-Pb at $\sqrt{s_{_{\rm NN}}} = 5.02$ TeV recorded with the ALICE detector. These measurements are performed as a function of multiplicity in the mid-rapidity region $|\eta|<0.8$ for the transverse momentum range $0.2 < p_{\rm T} < 3.0$ GeV/$c$. An ordering of the coefficients $v_2 > v_3 > v_4$ is found in pp and p-Pb collisions, similar to that seen in large collision systems, while a weak $v_2$ multiplicity dependence is observed relative to nucleus--nucleus collisions in the same multiplicity range. Using the novel subevent method, $v_{2}$ measured in pp and p-Pb collisions with four-particle cumulants is found to be compatible with that from six-particle cumulants. The symmetric cumulants $SC(m,n)$ calculated with the subevent method which evaluate the correlation strength between $v_n^2$ and $v_m^2$ are also presented. The presented data, which add further support to the existence of long-range multi-particle azimuthal correlations in high multiplicity pp and p-Pb collisions, can neither be described by PYTHIA8 nor by IP-Glasma+MUSIC+UrQMD model calculations, and hence provide new insights into the understanding of collective effects in small collision systems.

43
data tables

$v_2\{2\}$ with $|\Delta \eta| > 1.4$ in pp collisions at $\sqrt{s} = 13$ TeV.

$v_3\{2\}$ with $|\Delta \eta| > 1.0$ in pp collisions at $\sqrt{s} = 13$ TeV.

$v_4\{2\}$ with $|\Delta \eta| > 1.0$ in pp collisions at $\sqrt{s} = 13$ TeV.