Nuclear modification factor of light neutral-meson spectra up to high transverse momentum in p-Pb collisions at $\sqrt{s_{NN}}$ = 8.16 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Lett.B 827 (2022) 136943, 2022.
Inspire Record 1856529 DOI 10.17182/hepdata.128138

Neutral pion ($\pi^{0}$) and $\eta$ meson production cross sections were measured up to unprecedentedly high transverse momenta ($p_{\rm T}$) in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV. The mesons were reconstructed via their two-photon decay channel in the rapidity interval $-1.3< y <0.3$ in the ranges of $0.4<p_{\rm T}<200$ GeV/$c$ and $1.0<p_{\rm T}<50$ GeV/$c$, respectively. The respective nuclear modification factor ($R_{\rm pPb}$) is presented for $p_{\rm T}$ up to of 200 and 30 GeV/$c$, where the former was achieved by extending the $\pi^{0}$ measurement in pp collisions at $\sqrt{s}$ = 8 TeV using the merged cluster technique. The values of $R_{\rm pPb}$ are below unity for $p_{\rm T}<10$ GeV/$c$, while they are consistent with unity for $p_{\rm T}>10$ GeV/$c$, leaving essentially no room for final state energy loss. The new data provide strong constraints for nuclear parton distribution and fragmentation functions over a broad kinematic range and are compared to model predictions as well as previous results at $\sqrt{s_{\rm NN}}$ = 5.02 TeV.

8 data tables

Invariant differential cross section of PI0 produced in inelastic p-Pb collisions at a centre-of-mass energy per nucleon of 8.16 TeV, the uncertainty of $\sigma_\mbox{MB}$ of 1.9% is not included in the systematic error.

Invariant differential cross section of PI0 produced in inelastic pp collisions at a centre-of-mass energy of 8 TeV, the uncertainty of $\sigma_\mbox{MB}$ of 2.6% is not included in the systematic error.

Invariant differential cross section of ETA produced in inelastic p-Pb collisions at a centre-of-mass energy per nucleon of 8.16 TeV, the uncertainty of $\sigma_\mbox{MB}$ of 1.9% is not included in the systematic error.

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Version 2
$\pi^0$ and $\eta$ meson production in proton-proton collisions at $\sqrt{s}=8$ TeV

The ALICE collaboration Acharya, Shreyasi ; Adam, Jaroslav ; Adamova, Dagmar ; et al.
Eur.Phys.J.C 78 (2018) 263, 2018.
Inspire Record 1620477 DOI 10.17182/hepdata.79044

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 $0.3<p_{\rm T}<35$ GeV/$c$ and $0.5<p_{\rm T}<35$ GeV/$c$, respectively. Next-to-leading order perturbative QCD calculations using fragmentation functions DSS14 for the $\pi^{0}$ and AESSS for the $\eta$ overestimate the cross sections of both neutral mesons, although such calculations agree with the measured $\eta/\pi^{0}$ ratio within uncertainties. The results were also compared with PYTHIA~8.2 predictions for which the Monash~2013 tune yields the best agreement with the measured neutral meson spectra. The measurements confirm a universal behavior of the $\eta/\pi^{0}$ ratio seen for NA27, PHENIX and ALICE data for pp collisions from $\sqrt{s}=27.5$ GeV to $\sqrt{s}=8$ TeV within experimental uncertainties. A relation between the $\pi^{0}$ and $\eta$ production cross sections for pp collisions at $\sqrt{s}=8$ TeV is given by $m_{\rm T}$ scaling for $p_{\rm T}>3.5$ GeV/$c$. However, a deviation from this empirical scaling rule is observed for transverse momenta below $p_{\rm T}<3.5$ GeV/$c$ in the $\eta/\pi^0$ ratio with a significance of $6.2\sigma$.

16 data tables

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 $\pi^0$ 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.

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Production of $\pi^0$ and $\eta$ mesons up to high transverse momentum in pp collisions at 2.76 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
Eur.Phys.J.C 77 (2017) 339, 2017.
Inspire Record 1512110 DOI 10.17182/hepdata.77976

The invariant differential cross sections for inclusive $\pi^{0}$ and $\eta$ mesons at midrapidity were measured in pp collisions at $\sqrt{s}=2.76$ TeV for transverse momenta $0.4<p_{\rm T}<40$ GeV/$c$ and $0.6<p_{\rm T}<20$ GeV/$c$, respectively, using the ALICE detector. This large range in $p_{\rm T}$ was achieved by combining various analysis techniques and different triggers involving the electromagnetic calorimeter (EMCal). In particular, a new single-cluster, shower-shape based method was developed for the identification of high-$p_{\rm T}$ neutral pions, which exploits that the showers originating from their decay photons overlap in the EMCal. The measured cross sections are found to exhibit a similar power-law behavior with an exponent of about $6.3$. Next-to-leading-order perturbative QCD calculations differ from the measured cross sections by about $30$% for the $\pi^0$, and between $30$-$50$% for the $\eta$ meson, while generator-level simulations with PYTHIA 8.2 describe the data to better than $10$-$30$%, except at $p_{\rm T}<1$ GeV/$c$. The new data can therefore be used to further improve the theoretical description of $\pi^{0}$ and $\eta$ meson production.

5 data tables

Invariant differential yields of $\pi^0$ produced in inelastic pp collisions at center-of-mass energy 2.76 TeV, the normalization uncertainties of 5.7% are not included in the systematic error.

Invariant differential yields of $\eta$ produced in inelastic pp collisions at center-of-mass energy 2.76 TeV, the normalization uncertainties of 5.7% are not included in the systematic error.

Invariant differential cross section of $\pi^0$ produced in inelastic pp collisions at center-of-mass energy 2.76 TeV, the uncertainty of $\sigma_{MB}$ of 2.5% is not included in the systematic error.

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Cross Section and Transverse Single-Spin Asymmetry of $\eta$ Mesons in $p^{\uparrow}+p$ Collisions at $\sqrt{s}=200$ GeV at Forward Rapidity

The PHENIX collaboration Adare, A. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.D 90 (2014) 072008, 2014.
Inspire Record 1300542 DOI 10.17182/hepdata.64267

We present a measurement of the cross section and transverse single-spin asymmetry ($A_N$) for $\eta$ mesons at large pseudorapidity from $\sqrt{s}=200$~GeV $p^{\uparrow}+p$ collisions. The measured cross section for $0.5<p_T<5.0$~GeV/$c$ and $3.0<|\eta|<3.8$ is well described by a next-to-leading-order perturbative-quantum-chromodynamics calculation. The asymmetries $A_N$ have been measured as a function of Feynman-$x$ ($x_F$) from $0.2<|x_{F}|<0.7$, as well as transverse momentum ($p_T$) from $1.0<p_T<4.5$~GeV/$c$. The asymmetry averaged over positive $x_F$ is $\langle{A_{N}}\rangle=0.061{\pm}0.014$. The results are consistent with prior transverse single-spin measurements of forward $\eta$ and $\pi^{0}$ mesons at various energies in overlapping $x_F$ ranges. Comparison of different particle species can help to determine the origin of the large observed asymmetries in $p^{\uparrow}+p$ collisions.

4 data tables

The measured ETA meson cross section, E*D3(SIG)/DP**3, versus PT at forward rapidity. The statistical and systematic uncertainties are type-A and type-B uncertainties respectively.

ASYM(PEAK) and ASYM(BG) for ETA mesons measured as a function of XF in the range 0.3 < ABS(XF) < 0.7 from the 4X4B triggered dataset. The values represented are the weighted mean of the South and North MPC (Muon Piston Calorimeter). The uncertainties listed are statistical only.

ASYM for ETA mesons measured as a function of XF in the range 0.2 < ABS(XF) < 0.7. Uncertainties listed are those due to the statistics, the XF uncorrelated uncertainties due to extracting the yields, and the correlated relative luminosity uncertainty.

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Inclusive double-helicity asymmetries in neutral pion and eta meson production in $\vec{p}+\vec{p}$ collisions at $\sqrt{s}=200$ GeV

The PHENIX collaboration Adare, A. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.D 90 (2014) 012007, 2014.
Inspire Record 1282448 DOI 10.17182/hepdata.64716

Results are presented from data recorded in 2009 by the PHENIX experiment at the Relativistic Heavy Ion Collider for the double-longitudinal spin asymmetry, $A_{LL}$, for $\pi^0$ and $\eta$ production in $\sqrt{s} = 200$ GeV polarized $p$$+$$p$ collisions. Comparison of the $\pi^0$ results with different theory expectations based on fits of other published data showed a preference for small positive values of gluon polarization, $\Delta G$, in the proton in the probed Bjorken $x$ range. The effect of adding the new 2009 \pz data to a recent global analysis of polarized scattering data is also shown, resulting in a best fit value $\Delta G^{[0.05,0.2]}_{\mbox{DSSV}} = 0.06^{+0.11}_{-0.15}$ in the range $0.05<x<0.2$, with the uncertainty at $\Delta \chi^2 = 9$ when considering only statistical experimental uncertainties. Shifting the PHENIX data points by their systematic uncertainty leads to a variation of the best-fit value of $\Delta G^{[0.05,0.2]}_{\mbox{DSSV}}$ between $0.02$ and $0.12$, demonstrating the need for full treatment of the experimental systematic uncertainties in future global analyses.

9 data tables

PI0 ASYM(LL) measurements from 2005.

PI0 ASYM(LL) measurements from 2006.

PI0 ASYM(LL) measurements from 2009.

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Neutral pion and $\eta$ meson production in proton-proton collisions at $\sqrt{s}=0.9$ TeV and $\sqrt{s}=7$ TeV

The ALICE collaboration Abelev, B. ; Abrahantes Quintana, A. ; Adamova, D. ; et al.
Phys.Lett.B 717 (2012) 162-172, 2012.
Inspire Record 1116147 DOI 10.17182/hepdata.58871

The first measurements of the invariant differential cross sections of inclusive $\pi^0$ and $\eta$ meson production at mid-rapidity in proton-proton collisions at $\sqrt{s}=0.9$ TeV and $\sqrt{s}=7$ TeV are reported. The $\pi^0$ measurement covers the ranges $0.4<p_T<7$ GeV/$c$ and $0.3<p_T<25$ GeV/$c$ for these two energies, respectively. The production of $\eta$ mesons was measured at $\sqrt{s}=7$ TeV in the range $0.4<p_T<15$ GeV/$c$. Next-to-Leading Order perturbative QCD calculations, which are consistent with the $\pi^0$ spectrum at $\sqrt{s}=0.9$ TeV, overestimate those of $\pi^0$ and $\eta$ mesons at $\sqrt{s}=7$ TeV, but agree with the measured $\eta/\pi^0$ ratio at $\sqrt{s}=7$ TeV.

4 data tables

The measured invariant differential section for inclusive PI0 production at a centre-of-mass energy of 7 TeV.

The measured invariant differential section for inclusive PI0 production at a centre-of-mass energy of 0.9 TeV.

The measured invariant differential section for inclusive ETA production at a centre-of-mass energy of 7 TeV.

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Transverse momentum dependence of meson suppression in Au+Au collisions at sqrt(s_NN) = 200 GeV

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 82 (2010) 011902, 2010.
Inspire Record 856259 DOI 10.17182/hepdata.106472

New measurements by the PHENIX experiment at RHIC for eta production at midrapidity as a function of transverse momentum (p_T) and collision centrality in sqrt(s_NN) = 200 GeV Au+Au and p+p collisions are presented. They indicate nuclear modification factors (R_AA) that are similar both in magnitude and trend to those found in earlier pi^0 measurements. Linear fits to R_AA in the 5--20 GeV/c p_T region show that the slope is consistent with zero within two standard deviations at all centralities although a slow rise cannot be excluded. Having different statistical and systematic uncertainties the pi^0 and eta measurements are complementary at high p_T/ thus, along with the extended p_T range of these data they can provide additional constraints for theoretical modeling and the extraction of transport properties.

25 data tables

$E\frac{dN^3}{dp^3}$ vs. $p_T$, 0% to 5% centrality $Au+Au$. 90% Limit on 18-20 and 20-22 GeV/c bins.

$E\frac{dN^3}{dp^3}$ vs. $p_T$, 0% to 10% centrality $Au+Au$. 90% Limit on 18-20 and 20-22 GeV/c bins.

$E\frac{dN^3}{dp^3}$ vs. $p_T$, 10% to 20% centrality $Au+Au$.

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Production of pi0 and eta mesons at large transverse momenta in pp and p Be interactions at 530-GeV/c and 800-GeV/c

The Fermilab E706 collaboration Apanasevich, L. ; Bacigalupi, J. ; Baker, W. ; et al.
Phys.Rev.D 68 (2003) 052001, 2003.
Inspire Record 585866 DOI 10.17182/hepdata.11186

We present results on the production of high transverse momentum pizero and eta mesons in pp and pBe interactions at 530 and 800 GeV/c. The data span the kinematic ranges: 1 < p_T < 10 GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive pizero cross sections are compared with next-to-leading order QCD calculations and to expectations based on a phenomenological parton-k_T model.

21 data tables

Invariant differetrial cross sections/nucleon for the inclusive reaction p Be --> pi0 X at 530 and 800 GEV, averaged over the c.m. rapidity interval -0.75 to 0.75 and -1.0 to 0.5 respectively.

Invariant differetrial cross sections/nucleon for the inclusive reaction p p --> pi0 X at 530 and 800 GEV, averaged over the c.m. rapidity interval -0.75 to 0.75 and -1.0 to 0.5 respectively.

The averaged invariant differential cross section/nucleon as a function of rapidity in the PT intervals 1.0-1.5, 1.5-2.0 and 2.0-2.5 GeV for the inclusive reaction p BE --> pi0 X at 530 and 800 GeV GeV.

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Measurement of single spin asymmetry in eta meson production in p(pol.) p and in anti-p(pol.) p interactions in the beam fragmentation region at 200-GeV/c.

The Fermilab E704 collaboration Adams, D.L. ; Bonner, B.E. ; Corcoran, M.D. ; et al.
Nucl.Phys.B 510 (1998) 3-11, 1998.
Inspire Record 449811 DOI 10.17182/hepdata.51687

We present experimental results on measuring a single spin asymmetry in η-meson production in the interaction of transversely polarized protons and antiprotons at p lab = 200 GeV / c with a proton target in the region 0.2 < x F < 0.7 for p ↑ p , 0.3 < x F < 0.7 for p ̄ ↑p and 0.7 < p T < 2.0 GeV / c . A comparison of single spin asymmetries in π- and η-meson production is made.

2 data tables

The true asymmetry for ETA production in proton-proton collisions.

The true asymmetry for ETA production in antiproton-proton collisions.


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.

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