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Measurement of charged pion, kaon, and proton production in proton-proton collisions at sqrt(s) = 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.D 96 (2017) 112003, 2017.
Inspire Record 1608166 DOI 10.17182/hepdata.80168

Transverse momentum spectra of charged pions, kaons, and protons are measured in proton-proton collisions at sqrt(s) = 13 TeV with the CMS detector at the LHC. The particles, identified via their energy loss in the silicon tracker, are measured in the transverse momentum range of pt ~ 0.1-1.7 GeV and rapidities abs(y) < 1. The pt spectra and integrated yields are compared to previous results at smaller sqrt(s) and to predictions of Monte Carlo event generators. The average pt increases with particle mass and charged particle multiplicity of the event. Comparisons with previous CMS results at sqrt(s) = 0.9, 2.76, and 7 TeV show that the average pt and the ratios of hadron yields feature very similar dependences on the particle multiplicity in the event, independently of the center-of-mass energy of the pp collision.

89 data tables

Measured transverse momentum distributions of identified charged hadrons (PI+, K+ and P) at a centre-of-mass energy of 13 TeV.

Measured transverse momentum distributions of identified charged hadrons (PI+, K+ and P) at a centre-of-mass energy of 13 TeV.

Measured transverse momentum distributions of identified charged hadrons (PI-, K- and PBAR) at a centre-of-mass energy of 13 TeV.

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Production of charged pions, kaons and (anti-)protons in Pb-Pb and inelastic pp collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adhya, Souvik Priyam ; et al.
Phys.Rev.C 101 (2020) 044907, 2020.
Inspire Record 1759506 DOI 10.17182/hepdata.104923

Mid-rapidity production of $\pi^{\pm}$, $\rm{K}^{\pm}$ and ($\bar{\rm{p}}$)p measured by the ALICE experiment at the LHC, in Pb-Pb and inelastic pp collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV, is presented. The invariant yields are measured over a wide transverse momentum ($p_{\rm{T}}$) range from hundreds of MeV/$c$ up to 20 GeV/$c$. The results in Pb-Pb collisions are presented as a function of the collision centrality, in the range 0$-$90%. The comparison of the $p_{\rm{T}}$-integrated particle ratios, i.e. proton-to-pion (p/$\pi$) and kaon-to-pion (K/$\pi$) ratios, with similar measurements in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV show no significant energy dependence. Blast-wave fits of the $p_{\rm{T}}$ spectra indicate that in the most central collisions radial flow is slightly larger at 5.02 TeV with respect to 2.76 TeV. Particle ratios (p/$\pi$, K/$\pi$) as a function of $p_{\rm{T}}$ show pronounced maxima at $p_{\rm{T}}$ $\approx$ 3 GeV/$c$ in central Pb-Pb collisions. At high $p_{\rm{T}}$, particle ratios at 5.02 TeV are similar to those measured in pp collisions at the same energy and in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV. Using the pp reference spectra measured at the same collision energy of 5.02 TeV, the nuclear modification factors for the different particle species are derived. Within uncertainties, the nuclear modification factor is particle species independent for high $p_{\rm{T}}$ and compatible with measurements at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV. The results are compared to state-of-the-art model calculations, which are found to describe the observed trends satisfactorily.

17 data tables

$p_{T}$-distributions of pions ($\pi^{+}+\pi^{-}$) measured in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV.

$p_{T}$-distributions of pions ($\pi^{+}+\pi^{-}$) measured in pp collisions at $\sqrt{s}$ = 5.02 TeV.

$p_{T}$-distributions of kaons ($K^{+}+K^{-}$) measured in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV.

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Proton-Proton Interactions and Onset of Deconfinement

The NA61/SHINE collaboration Aduszkiewicz, A. ; Andronov, E.V. ; Anticic, T. ; et al.
Phys.Rev.C 102 (2020) 011901, 2020.
Inspire Record 1772241 DOI 10.17182/hepdata.95182

The NA61/SHINE experiment at the CERN SPS is performing a uniqe study of the phase diagram of strongly interacting matter by varying collision energy and nuclear mass number of colliding nuclei. In central Pb+Pb collisions the NA49 experiment found structures in the energy dependence of several observables in the CERN SPS energy range that had been predicted for the transition to a deconfined phase. New measurements of NA61/SHINE find intriguing similarities in p+p interactions for which no deconfinement transition is expected at SPS energies. Possible implications will be discussed.

12 data tables

K+/PI+ at y=0.

K+/PI+ at y=0.

<K+>/<PI+>.

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Evidence of rescattering effect in Pb-Pb collisions at the LHC through production of $\rm{K}^{*}(892)^{0}$ and $\phi(1020)$ mesons

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Lett.B 802 (2020) 135225, 2020.
Inspire Record 1762368 DOI 10.17182/hepdata.93150

Measurements of $\rm{K}^{*}(892)^{0}$ and $\phi(1020)$ resonance production in Pb-Pb and pp collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV with the ALICE detector at the Large Hadron Collider are reported. The resonances are measured at midrapidity ($|y|$ $<$ 0.5) via their hadronic decay channels and the transverse momentum ($p_{\rm{T}}$) distributions are obtained for various collision centrality classes up to $p_{\rm{T}}$ $=$ 20 GeV$/c$. The $p_{\rm{T}}$-integrated yield ratio $\rm{K}^{*}(892)^{0}$$/$K in Pb-Pb collisions shows significant suppression relative to pp collisions and decreases towards more central collisions. In contrast, the $\phi(1020)$$/$K ratio does not show any suppression. Furthermore, the measured $\rm{K}^{*}(892)^{0}$$/$K ratio in central Pb-Pb collisions is significantly suppressed with respect to the expectations based on a thermal model calculation, while the $\phi(1020)$$/$K ratio agrees with the model prediction. These measurements are an experimental demonstration of rescattering of $\rm{K}^{*}(892)^{0}$ decay products in the hadronic phase of the collisions. The $\rm{K}^{*}(892)^{0}$$/$K yield ratios in Pb-Pb and pp collisions are used to estimate the time duration between chemical and kinetic freeze-out, which is found to be $\sim$ 4-7 fm$/c$ for central collisions. The $p_{\rm{T}}$-differential ratios of $\rm{K}^{*}(892)^{0}$$/$K, $\phi(1020)$$/$K, $\rm{K}^{*}(892)^{0}$$/\pi$, $\phi(1020)$$/\pi$, $p/$$\rm{K}^{*}(892)^{0}$ and $p/$$\phi(1020)$ are also presented for Pb-Pb and pp collisions at $\sqrt{s_{\rm{NN}}}$ $=$ 5.02 TeV. These ratios show that the rescattering effect is predominantly a low-$p_{\rm{T}}$ phenomenon.

20 data tables

$p_{\rm T}$-distributions of $\rm{K}^{*0}$ (average of particle and anti-particle) meson measured in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV.

$p_{\rm T}$-distributions of $\rm{K}^{*0}$ (average of particle and anti-particle) meson measured in pp collisions at $\sqrt{s}$ = 5.02 TeV.

$p_{\rm T}$-distributions of $\phi$ meson measured in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV.

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Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p-Pb collisions at $\mathbf{\sqrt{{\textit s}_{\rm NN}}}$ = 5.02 TeV

The ALICE collaboration Adam, Jaroslav ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
Phys.Lett.B 760 (2016) 720-735, 2016.
Inspire Record 1415274 DOI 10.17182/hepdata.73749

The production of charged pions, kaons and (anti)protons has been measured at mid-rapidity ($-0.5 y 0$) in p-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV using the ALICE detector at the LHC. Exploiting particle identification capabilities at high transverse momentum ($p_{\rm T}$), the previously published $p_{\rm T}$ spectra have been extended to include measurements up to 20 GeV/$c$ for seven event multiplicity classes. The $p_{\rm T}$ spectra for pp collisions at $\sqrt{s}=7$ TeV, needed to interpolate a pp reference spectrum, have also been extended up to 20 GeV/$c$ to measure the nuclear modification factor ($R_{\rm pPb}$) in non-single diffractive p-Pb collisions. At intermediate transverse momentum ($2 p_{\rm T} 10$\,GeV/$c$) the proton-to-pion ratio increases with multiplicity in p-Pb collisions, a similar effect is not present in the kaon-to-pion ratio. The $p_{\rm T}$ dependent structure of such increase is qualitatively similar to those observed in pp and heavy-ion collisions. At high $p_{\rm T}$ ($>10$ GeV/$c$), the particle ratios are consistent with those reported for pp and Pb-Pb collisions at the LHC energies. At intermediate $p_{\rm T}$ the (anti)proton $R_{\rm pPb}$ shows a Cronin-like enhancement, while pions and kaons show little or no nuclear modification. At high $p_{\rm T}$ the charged pion, kaon and (anti)proton $R_{\rm pPb}$ are consistent with unity within statistical and systematic uncertainties.

13 data tables

pT-differential invariant yield of charged pions in p-Pb collisions with centre-of-mass energy/nucleon=5.02 TeV, measured for different V0A multiplicity classes. The first uncertainty is statistical, the second one is the total systematic uncertainty, while the third one is the uncorrelated systematic uncertainty which is multiplicity dependent.

pT-differential invariant yield of charged pions in p-Pb collisions with centre-of-mass energy/nucleon=5.02 TeV, measured for NSD events. The first uncertainty is statistical, the second one is the total systematic uncertainty, while the third one is the uncorrelated systematic uncertainty which is multiplicity dependent.

pT-differential invariant yield of charged kaons in p-Pb collisions with centre-of-mass energy/nucleon=5.02 TeV, measured for different V0A multiplicity classes. The first uncertainty is statistical, the second one is the total systematic uncertainty, while the third one is the uncorrelated systematic uncertainty which is multiplicity dependent.

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Inclusive particle production in 400-GeV/c p p interactions

Aguilar-Benitez, M. ; Allison, W.W. W. ; Batalov, A.A. ; et al.
Z.Phys.C 50 (1991) 405-426, 1991.
Inspire Record 314091 DOI 10.17182/hepdata.1435

We report on a study of inclusive particle production in pp-interactions at 400 GeV/c. The data are based on 472 K reconstructed events recorded in the NA 27 experiment using the LEBC-EHS facility at CERN. The production cross sections are determined of pseudo scalar (π±,0, η andK±), scalar (f0(975)), vector (ρ±,0(770), ω(783), ϕ(1020),K*0(892), and\(\bar K^{ * 0} \)(892)), and tensorf0 mesons, of protons and antiprotons, and theΔ++,+,0(1232), and Λ(1520) baryon resonances in the forward hemisphere of the center of mass system, as well as longitudinal and transverse momentum distributions. The results are compared with predictions of the FRITIOF model and with other experimental data.

61 data tables

No description provided.

No description provided.

No description provided.

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Multipion Bose-Einstein correlations in pp, p-Pb, and Pb-Pb collisions at the LHC

The ALICE collaboration Adam, Jaroslav ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
Phys.Rev.C 93 (2016) 054908, 2016.
Inspire Record 1411653 DOI 10.17182/hepdata.72937

Three- and four-pion Bose-Einstein correlations are presented in pp, p-Pb, and Pb-Pb collisions at the LHC. We compare our measured four-pion correlations to the expectation derived from two- and three-pion measurements. Such a comparison provides a method to search for coherent pion emission. We also present mixed-charge correlations in order to demonstrate the effectiveness of several analysis procedures such as Coulomb corrections. Same-charge four-pion correlations in pp and p-Pb appear consistent with the expectations from three-pion measurements. However, the presence of non-negligible background correlations in both systems prevent a conclusive statement. In Pb-Pb collisions, we observe a significant suppression of three- and four-pion Bose-Einstein correlations compared to expectations from two-pion measurements. There appears to be no centrality dependence of the suppression within the 0-50% centrality interval. The origin of the suppression is not clear. However, by postulating either coherent pion emission or large multibody Coulomb effects, the suppression may be explained.

31 data tables

Mixed charge (- - - +) C4QS, a4QS, c4QS at low KT4 in pp collisions projected against Q4.

Mixed charge (- - - +) C4QS, a4QS, c4QS at high KT4 in pp collisions projected against Q4.

Mixed charge (- - - +) C4QS, a4QS, c4QS at low KT4 in pPb collisions projected against Q4.

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Production of K$^{*}$(892)$^{0}$ and $\phi$(1020) in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

The ALICE collaboration Adam, Jaroslav ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
Eur.Phys.J.C 76 (2016) 245, 2016.
Inspire Record 1418181 DOI 10.17182/hepdata.72720

The production of K$^{*}$(892)$^{0}$ and $\phi$(1020) mesons has been measured in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV. K$^{*0}$ and $\phi$ are reconstructed via their decay into charged hadrons with the ALICE detector in the rapidity range $-0.5 < y <0$. The transverse momentum spectra, measured as a function of the multiplicity, have p$_{\mathrm{T}}$ range from 0 to 15 GeV/$c$ for K$^{*0}$ and from 0.3 to 21 GeV/$c$ for $\phi$. Integrated yields, mean transverse momenta and particle ratios are reported and compared with results in pp collisions at $\sqrt{s}$ = 7 TeV and Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV. In Pb-Pb and p-Pb collisions, K$^{*0}$ and $\phi$ probe the hadronic phase of the system and contribute to the study of particle formation mechanisms by comparison with other identified hadrons. For this purpose, the mean transverse momenta and the differential proton-to-$\phi$ ratio are discussed as a function of the multiplicity of the event. The short-lived K$^{*0}$ is measured to investigate re-scattering effects, believed to be related to the size of the system and to the lifetime of the hadronic phase.

30 data tables

Average charged particle pseudo-rapidity density, $\langle\mathrm{d}N_{\rm ch}/\mathrm{d}\eta_{\mathrm{lab}}\rangle$, measured at mid-rapidity in visible cross section event classes and average number of colliding nucleons, $\langle\mathrm{N_{coll}}\rangle$. Multiplicity classes are defined using the V0A estimator; values for $\langle\mathrm{d}N_{\rm ch}/\mathrm{d}\eta_{\mathrm{lab}}\rangle$ are corrected for vertexing and trigger efficiency. Since statistical uncertainties are negligible, only total systematic uncertainties are reported.

$p_{\rm T}$-differential yield of (K$^{*0}$ + $\overline{K^{*0}}$)/2 in p-Pb collisions with centre-of-mass energy/nucleon=5.02 TeV (NSD). Additional systematic error: +- 3.1% (normalization).

$p_{\rm T}$-differential yield of (K$^{*0}$ + $\overline{K^{*0}}$)/2 in p-Pb collisions with centre-of-mass energy/nucleon=5.02 TeV (0-20% multiplicity class).

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Inclusive cross sections, charge ratio and double-helicity asymmetries for $\pi^+$ and $\pi^-$ production in $p$$+$$p$ collisions at $\sqrt{s}$=200 GeV

The PHENIX collaboration Adare, A. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.D 91 (2015) 032001, 2015.
Inspire Record 1315330 DOI 10.17182/hepdata.71403

We present the midrapidity charged pion invariant cross sections and the ratio of $\pi^-$-to-$\pi^+$ production ($5<p_T<13$ GeV/$c$), together with the double-helicity asymmetries ($5<p_T<12$ GeV/$c$) in polarized $p$$+$$p$ collisions at $\sqrt{s} = 200$ GeV. The cross section measurements are consistent with perturbative calculations in quantum chromodynamics within large uncertainties in the calculation due to the choice of factorization, renormalization, and fragmentation scales. However, the theoretical calculation of the ratio of $\pi^-$-to-$\pi^+$ production when considering these scale uncertainties overestimates the measured value, suggesting further investigation of the uncertainties on the charge-separated pion fragmentation functions is needed. Due to cancellations of uncertainties in the charge ratio, direct inclusion of these ratio data in future parameterizations should improve constraints on the flavor dependence of quark fragmentation functions to pions. By measuring charge-separated pion asymmetries, one can gain sensitivity to the sign of $\Delta G$ through the opposite sign of the up and down quark helicity distributions in conjunction with preferential fragmentation of positive pions from up quarks and negative pions from down quarks. The double-helicity asymmetries presented are sensitive to the gluon helicity distribution over an $x$ range of $\sim$0.03--0.16.

3 data tables

Invariant cross section for $\pi^+$ and $\pi^-$ hadrons, as well as the statistical and systematic uncertainties. In addition, there is an absolute scale uncertainty of 9.6$\%$.

Double-helicity asymmetries and statistical uncertainties for $\pi^+$ and $\pi^-$ hadrons. The primary systematic uncertainties, which are fully correlated between points, are $1.4\times10^{-3}$ from relative luminosity and a $^{+7.0\%}_{-7.7\%}$ scaling uncertainty from beam polarization.

Ratio of charged pion cross section, as shown in Fig.6.


Centrality dependence of the nuclear modification factor of charged pions, kaons, and protons in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV

The ALICE collaboration Adam, Jaroslav ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
Phys.Rev.C 93 (2016) 034913, 2016.
Inspire Record 1377750 DOI 10.17182/hepdata.71310

Transverse momentum ($p_{\rm{T}}$) spectra of pions, kaons, and protons up to $p_{\rm{T}} = 20$ GeV/$c$ have been measured in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV using the ALICE detector for six different centrality classes covering 0-80%. The proton-to-pion and the kaon-to-pion ratios both show a distinct peak at $p_{\rm{T}} \approx 3$ GeV/$c$ in central Pb-Pb collisions that decreases towards more peripheral collisions. For $p_{\rm{T}} > 10$ GeV/$c$, the nuclear modification factor is found to be the same for all three particle species in each centrality interval within systematic uncertainties of 10-20%. This suggests there is no direct interplay between the energy loss in the medium and the particle species composition in the hard core of the quenched jet. For $p_{\rm{T}} < 10$ GeV/$c$, the data provide important constraints for models aimed at describing the transition from soft to hard physics.

16 data tables

Invariant yields of identified pions in Pb-Pb collisions.

Invariant yields of identified kaons in Pb-Pb collisions.

Invariant yields of identified protons in Pb-Pb collisions.

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