rho0 production and possible modification in Au + Au and p + p collisions at s(NN)**(1/2) = 200-GeV.

The STAR collaboration Adams, J. ; Adler, C. ; Aggarwal, M.M. ; et al.
Phys.Rev.Lett. 92 (2004) 092301, 2004.
Inspire Record 624475 DOI 10.17182/hepdata.99052

We report results on rho(770)^0 -> pi+pi- production at midrapidity in p+p and peripheral Au+Au collisions at sqrt(s_NN) = 200 GeV. This is the first direct measurement of rho(770)^0 -> pi+pi- in heavy-ion collisions. The measured rho^0 peak in the invariant mass distribution is shifted by ~40 MeV/c^2 in minimum bias p+p interactions and ~70 MeV/c^2 in peripheral Au+Au collisions. The rho^0 mass shift is dependent on transverse momentum and multiplicity. The modification of the rho^0 meson mass, width, and shape due to phase space and dynamical effects are discussed.

1 data table match query

$\rho^{0}/\pi$ ratios as a function of c.m. system energy. The ratios are from measurements in $e^{+} e^{−}$ collisions at $10.45$ GeV, $29$ GeV and $91$ GeV c.m. system energy, $p$+$p$ at $6.8$ GeV, $19.7$ GeV, $27.5$ GeV, and $52.5$ GeV, Kp at $7.82$ GeV and $\pi^{-}$p at $19.6$ GeV. The errors on the ratios at $\sqrt{s_{NN}}= 200$ GeV are the quadratic sum of the statistical and systematic errors. The ratios at $\sqrt{s_{NN}}= 200$ GeV are offset from one another for clarity.


pi0 photoproduction on the proton for photon energies from 0.675-GeV to 2.875-GeV.

Dugger, M. ; Ritchie, Barry G. ; Ball, J.P. ; et al.
Phys.Rev.C 76 (2007) 025211, 2007.
Inspire Record 749989 DOI 10.17182/hepdata.51855

Differential cross sections for the reaction $\gamma p \to p \pi^0$ have been measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged photon beam with energies from 0.675 to 2.875 GeV. The results reported here possess greater accuracy in the absolute normalization than previous measurements. They disagree with recent CB-ELSA measurements for the process at forward scattering angles. Agreement with the SAID and MAID fits is found below 1 GeV. The present set of cross sections has been incorporated into the SAID database, and exploratory fits have been extended to 3 GeV. Resonance couplings have been extracted and compared to previous determinations.

43 data tables match query

Differential cross section for indicent photon energy 675 MeV.

Differential cross section for indicent photon energy 725 MeV.

Differential cross section for indicent photon energy 775 MeV.

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pi+-, K+-, p and anti-p production in Z0 --> q anti-q, Z0 --> b anti-b, Z0 --> u anti-u, d anti-d, s anti-s.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Eur.Phys.J.C 5 (1998) 585-620, 1998.
Inspire Record 473409 DOI 10.17182/hepdata.49385

The DELPHI experiment at LEP uses Ring Imaging Cherenkov detectors for particle identification. The good understanding of the RICH detectors allows the identification of charged pions, kaons and proto

1 data table match query

Differential cross section for P PBAR in Z0-->Q-QBAR events.


pi+- p differential cross sections at low energies.

Denz, H. ; Amaudruz, P. ; Brack, J.T. ; et al.
Phys.Lett.B 633 (2006) 209-213, 2006.
Inspire Record 699647 DOI 10.17182/hepdata.31620

Differential cross sections for pi- p and pi+ p elastic scattering were measured at five energies between 19.9 and 43.3 MeV. The use of the CHAOS magnetic spectrometer at TRIUMF, supplemented by a range telescope for muon background suppression, provided simultaneous coverage of a large part of the full angular range, thus allowing very precise relative cross section measurements. The absolute normalisation was determined with a typical accuracy of 5 %. This was verified in a simultaneous measurement of muon proton elastic scattering. The measured cross sections show some deviations from phase shift analysis predictions, in particular at large angles and low energies. From the new data we determine the real part of the isospin forward scattering amplitude.

12 data tables match query

Elastic PI- P cross section for incident kinetic energy 43.3 MeV for the rotated target data. Errors shown are statistical only.

Elastic PI- P cross section for incident kinetic energy 43.3 MeV. Errors shown are statistical only.

Elastic PI- P cross section for incident kinetic energy 37.1 MeV. Errors shown are statistical only.

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Wide-angle proton-proton elastic scattering from 1.3 to 3.0 gev/c

Williams, D.T. ; Bloodworth, I.J. ; Eisenhandler, E. ; et al.
Nuovo Cim.A 8 (1972) 447-469, 1972.
Inspire Record 78276 DOI 10.17182/hepdata.37468

Differential cross-sections for proton-proton elastic scattering have been measured covering the angular range from 50° to 90° c.m. at twelve incident momenta from 1.3 to 3.0 GeV/c. The angular distributions are quite smooth, but there is evidence of structure in the energy dependence of fixed-angle cross-sections at |t| ∼ 1 (GeV)2.

1 data table match query

No description provided.


Upsilon production in U+U collisions at 193 GeV with the STAR experiment

The STAR collaboration Adamczyk, L. ; Adkins, J.K. ; Agakishiev, G. ; et al.
Phys.Rev.C 94 (2016) 064904, 2016.
Inspire Record 1482939 DOI 10.17182/hepdata.98624

We present a measurement of the inclusive production of Upsilon mesons in U+U collisions at 193 GeV at mid-rapidity (|y| < 1). Previous studies in central Au+Au collisions at 200 GeV show a suppression of Upsilon(1S+2S+3S) production relative to expectations from the Upsilon yield in p+p collisions scaled by the number of binary nucleon-nucleon collisions (Ncoll), with an indication that the Upsilon(1S) state is also suppressed. The present measurement extends the number of participant nucleons in the collision (Npart) by 20% compared to Au+Au collisions, and allows us to study a system with higher energy density. We observe a suppression in both the Upsilon(1S+2S+3S) and Upsilon(1S) yields in central U+U data, which consolidates and extends the previously observed suppression trend in Au+Au collisions.

1 data table match query

(Color online) Quarkonium $R_{AA}$ versus binding energy in Au+Au and U+U collisions. Open symbols represent 0-60% centrality data, filled symbols are for 0-10% centrality. The $\Upsilon$ measurements in U+U collisions are denoted by red points. In the case of Au+Au collisions, the $\Upsilon$(1S) measurement is denoted by a blue square, while for the $\Upsilon$(2S+3S) states, a blue horizontal line indicates a 95% upper confidence bound. The black diamonds mark the high-$p_{T}$ $J/\psi$ measurement. The vertical lines represent nominal binding energies for the $\Upsilon$(1S) and $J/\psi$, calculated based on the mass defect, as 2$m_{D}$ $−m_{J/\psi}$ and 2$m_{B} −m_{$\Upsilon$}$, respectively (where $m_{X}$ is the mass of the given meson X) [39]. The shaded area spans between the binding energies of $\Upsilon$(2S) and $\Upsilon$(3S). The data points are slightly shifted to the left and right from the nominal binding energy values to improve their visibility.


Upsilon cross section in p+p collisions at sqrt(s) = 200 GeV

The STAR collaboration Abelev, B.I. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.D 82 (2010) 012004, 2010.
Inspire Record 842959 DOI 10.17182/hepdata.97119

We report on a measurement of the Upsilon(1S+2S+3S) -> e+e- cross section at midrapidity in p+p collisions at sqrt(s)=200 GeV. We find the cross section to be 114 +/- 38 (stat.) +23,-24 (syst.) pb. Perturbative QCD calculations at next-to-leading order in the Color Evaporation Model are in agreement with our measurement, while calculations in the Color Singlet Model underestimate it by 2 sigma. Our result is consistent with the trend seen in world data as a function of the center-of-mass energy of the collision and extends the availability of Upsilon data to RHIC energies. The dielectron continuum in the invariant mass range near the Upsilon is also studied to obtain a combined cross section of Drell-Yan plus (b b-bar) -> e+e-.

1 data table match query

Evolution of the Upsilon(1S+2S+3S) cross section with center-of-mass energy.


Two-pion Bose-Einstein correlations in pp collisions at sqrt(s)=900 GeV

The ALICE collaboration Aamodt, K ; Abel, N ; Abeysekara, U. ; et al.
Phys.Rev.D 82 (2010) 052001, 2010.
Inspire Record 860477 DOI 10.17182/hepdata.55128

We report on the measurement of two-pion correlation functions from pp collisions at $\sqrt{s}=900$ GeV performed by the ALICE experiment at the Large Hadron Collider. Our analysis shows an increase of the HBT radius with increasing event multiplicity, in line with other measurements done in particle- and nuclear collisions. Conversely, the strong decrease of the radius with increasing transverse momentum, as observed at RHIC and at Tevatron, is not manifest in our data.

1 data table match query

Simulated two-particle correlation functions, using PHOJET, for like-sign and unlike sign pion pairs.


Tuning and test of fragmentation models based on identified particles and precision event shape data.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Z.Phys.C 73 (1996) 11-60, 1996.
Inspire Record 424112 DOI 10.17182/hepdata.47800

Event shape and charged particle inclusive distributions are measured using 750000 decays of the Z to hadrons from the DELPHI detector at LEP. These precise data allow a decisive confrontation with models of the hadronization process. Improved tunings of the JETSET, ARIADNE and HERWIG parton shower models and the JETSET matrix element model are obtained by fitting the models to these DELPHI data as well as to identified particle distributions from all LEP experiments. The description of the data distributions by the models is critically reviewed with special importance attributed to identified particles.

3 data tables match query

Difference in Hemisphere Masses. Corrected to final state particles.

Energy-Energy Correlation EEC. Corrected to final state particles.

Asymmetry of the Energy-Energy Correlation AEEC. Corrected to final state particles.


Trends in Yield and Azimuthal Shape Modification in Dihadron Correlations in Relativistic Heavy Ion Collisions

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.Lett. 104 (2010) 252301, 2010.
Inspire Record 845169 DOI 10.17182/hepdata.146557

Fast parton probes produced by hard scattering and embedded within collisions of large nuclei have shown that partons suffer large energy loss and that the produced medium may respond collectively to the lost energy. We present measurements of neutral pion trigger particles at transverse momenta p^t_T = 4-12 GeV/c and associated charged hadrons (p^a_T = 0.5-7 GeV/c) as a function of relative azimuthal angle Delta Phi at midrapidity in Au+Au and p+p collisions at sqrt(s_NN) = 200 GeV. These data lead to two major observations. First, the relative angular distribution of low momentum hadrons, whose shape modification has been interpreted as a medium response to parton energy loss, is found to be modified only for p^t_T &lt; 7 GeV/c. At higher p^t_T, the data are consistent with unmodified or very weakly modified shapes, even for the lowest measured p^a_T. This observation presents a quantitative challenge to medium response scenarios. Second, the associated yield of hadrons opposite to the trigger particle in Au+Au relative to that in p+p (I_AA) is found to be suppressed at large momentum (IAA ~ 0.35-0.5), but less than the single particle nuclear modification factor (R_AA ~0.2).

16 data tables match query

Average away-side $I^{head}_{AA}$ above 2 GeV/$c$ for various $\pi^0$ trigger momenta in central and midcentral collisions where $|\Delta\phi - \pi| < \pi/6$. Note: a 6% scale uncertainty applies to all $I_{AA}$ values.

Away-side jet widths from a Gaussian fit by $h^{\pm}$ partner momentum for various $\pi^0$ trigger momenta in $p+p$ collisions.

Away-side jet widths from a Gaussian fit by $h^{\pm}$ partner momentum for various $\pi^0$ trigger momenta in Au+Au collisions.

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Transverse-energy distributions at midrapidity in $p$$+$$p$, $d$$+$Au, and Au$+$Au collisions at $\sqrt{s_{_{NN}}}=62.4$--200~GeV and implications for particle-production models

The PHENIX collaboration Adler, S.S. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 89 (2014) 044905, 2014.
Inspire Record 1273625 DOI 10.17182/hepdata.63512

Measurements of the midrapidity transverse energy distribution, $d\Et/d\eta$, are presented for $p$$+$$p$, $d$$+$Au, and Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV and additionally for Au$+$Au collisions at $\sqrt{s_{_{NN}}}=62.4$ and 130 GeV. The $d\Et/d\eta$ distributions are first compared with the number of nucleon participants $N_{\rm part}$, number of binary collisions $N_{\rm coll}$, and number of constituent-quark participants $N_{qp}$ calculated from a Glauber model based on the nuclear geometry. For Au$+$Au, $\mean{d\Et/d\eta}/N_{\rm part}$ increases with $N_{\rm part}$, while $\mean{d\Et/d\eta}/N_{qp}$ is approximately constant for all three energies. This indicates that the two component ansatz, $dE_{T}/d\eta \propto (1-x) N_{\rm part}/2 + x N_{\rm coll}$, which has been used to represent $E_T$ distributions, is simply a proxy for $N_{qp}$, and that the $N_{\rm coll}$ term does not represent a hard-scattering component in $E_T$ distributions. The $dE_{T}/d\eta$ distributions of Au$+$Au and $d$$+$Au are then calculated from the measured $p$$+$$p$ $E_T$ distribution using two models that both reproduce the Au$+$Au data. However, while the number-of-constituent-quark-participant model agrees well with the $d$$+$Au data, the additive-quark model does not.

1 data table match query

dE_T/deta normalized by the number of participant pairs as a function of the number of participants.


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.

4 data tables match query

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

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Transverse energy production and charged-particle multiplicity at midrapidity in various systems from $\sqrt{s_{NN}}=7.7$ to 200 GeV

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 93 (2016) 024901, 2016.
Inspire Record 1394433 DOI 10.17182/hepdata.96601

Measurements of midrapidity charged particle multiplicity distributions, $dN_{\rm ch}/d\eta$, and midrapidity transverse-energy distributions, $dE_T/d\eta$, are presented for a variety of collision systems and energies. Included are distributions for Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$, 130, 62.4, 39, 27, 19.6, 14.5, and 7.7 GeV, Cu$+$Cu collisions at $\sqrt{s_{_{NN}}}=200$ and 62.4 GeV, Cu$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV, U$+$U collisions at $\sqrt{s_{_{NN}}}=193$ GeV, $d$$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV, $^{3}$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV, and $p$$+$$p$ collisions at $\sqrt{s_{_{NN}}}=200$ GeV. Centrality-dependent distributions at midrapidity are presented in terms of the number of nucleon participants, $N_{\rm part}$, and the number of constituent quark participants, $N_{q{\rm p}}$. For all $A$$+$$A$ collisions down to $\sqrt{s_{_{NN}}}=7.7$ GeV, it is observed that the midrapidity data are better described by scaling with $N_{q{\rm p}}$ than scaling with $N_{\rm part}$. Also presented are estimates of the Bjorken energy density, $\varepsilon_{\rm BJ}$, and the ratio of $dE_T/d\eta$ to $dN_{\rm ch}/d\eta$, the latter of which is seen to be constant as a function of centrality for all systems.

15 data tables match query

Transverse energy in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV

Transverse energy in Au+Au collisions at $\sqrt{s_{NN}}$ = 130 GeV

Transverse energy in Au+Au collisions at $\sqrt{s_{NN}}$ = 62.4 GeV

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Total Hadronic Photoabsorption Cross-Sections on Hydrogen and Complex Nuclei from 4-GeV to 18-GeV

Caldwell, David O. ; Elings, V.B. ; Hesse, W.P. ; et al.
Phys.Rev.D 7 (1973) 1362, 1973.
Inspire Record 83727 DOI 10.17182/hepdata.22181

Final total cross sections are given for a counter experiment at SLAC on hadronic photon absorption in hydrogen, deuterium, carbon, copper, and lead at incident energies from 3.7 to 18.3 GeV. Some of the nucleon cross sections have been revised and the C, Cu, and Pb data from 3.7 to 7.4 GeV have not been reported previously. The cross sections for complex nuclei vary approximately as A0.9 in our energy range, indicating that the photon interacts, at least partially, as a strongly interacting particle. The energy dependences of the proton and neutron cross sections are also similar to those of hadron-nucleon cross sections and hence may be fitted by a typical Regge parametrization, yielding σT(γp)=(98.7±3.6)+(65.0±10.1)ν−12 μb and σT(γn)=(103.4±6.7)+(33.1±19.4)ν−12 μb, where ν is the photon energy in GeV. These extrapolate to the same value at infinite energy, consistent with Pomeranchukon exchange, and the energy-dependent part yields an isovector-to-isoscalar-exchange ratio of 0.18 ± 0.06. While these observations are qualitatively consistent with vector meson dominance, quantitatively vector dominance fails in relating our results to ρ photo-production on hydrogen or to experiments determining the ρ-nucleon cross section. Vector dominance cannot be rescued by assuming that the ρ-photon coupling constant depends on the photon mass. Instead, an additional short-range interaction is apparently required, possibly due to a heavy (≳ 2 GeV / c2) vector meson or to a bare-photon interaction. The additional interaction accounts for approximately 20% of the total photoabsorption cross section.

2 data tables match query

DATA ARE GROUPED IN SETS OF FOUR TAGGING ENERGIES FOR EACH INCIDENT POSITRON ENERGY.

CROSS SECTIONS FOR EACH INCIDENT POSITRON ENERGY AVERAGED OVER THE FOUR TAGGING ENERGIES.


Total Cross-Sections of pi+-, K+-, p, and anti-p on Protons and Deuterons Between 23-GeV/c and 280-GeV/c

Carroll, A.S. ; Chiang, I.-H. ; Kycia, T.F. ; et al.
Phys.Lett.B 61 (1976) 303-308, 1976.
Inspire Record 98502 DOI 10.17182/hepdata.27688

New measurements are reported of total cross sections for π ± , K ± , p and p on protons and deuterons at 11 momenta between 23 and 280 GeV/ c .

1 data table match query

No description provided.


Total Cross-Sections of $\pi^{\pm}$, $K^{\pm}$, p and $\bar{p}$ on Protons and Deuterons Between 200 GeV/c and 370 GeV/c

Carroll, A.S. ; Chiang, I.H. ; Kycia, T.F. ; et al.
Phys.Lett.B 80 (1979) 423-427, 1979.
Inspire Record 132765 DOI 10.17182/hepdata.27362

Total cross sections of π ± , K ± , p and p on protons and deuterons have been measured at 6 momenta between 200 and 370 GeV/ c .

1 data table match query

No description provided.


Three- and four-jet final states in photoproduction at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 792 (2008) 1-47, 2008.
Inspire Record 756660 DOI 10.17182/hepdata.45526

Three- and four-jet final states have been measured in photoproduction at HERA using the ZEUS detector with an integrated luminosity of 121 pb^-1. The results are presented for jets with transverse energy E_T^jet>6 GeV and pseudorapidity |eta^jet|<2.4, in the kinematic region given by the virtuality of the photon Q^2<1 GeV^2 and the inelasticity 0.2<y<0.85 and in two mass regions defined as 25<M_nj<50 GeV and M_nj>50 GeV, where M_nj is the invariant mass of the n-jet system. The four-jet photoproduction cross section has been measured for the first time and represents the highest-order process studied at HERA. Both the three- and four-jet cross sections have been compared with leading-logarithmic parton-shower Monte Carlo models, with and without multi-parton interactions. The three-jet cross sections have been compared to an order(alpha alpha_s^2) perturbative QCD calculation.

1 data table match query

Cross section D(SIG)/COS(PSI(3)) as a function of COS(PSI(3)) in two jet invariant mass regions, 25 to 50 and > 50 GeV . PSI(3) is the angle in the 3-jet CM frame between the plane containing the highest energy jet (P=4) and the beam, and the plane containing the three jets .


Three- and Four-jet Production at Low x at HERA

The H1 collaboration Aaron, F.D. ; Aktas, A. ; Alexa, C. ; et al.
Eur.Phys.J.C 54 (2008) 389-409, 2008.
Inspire Record 767896 DOI 10.17182/hepdata.45429

Three- and four-jet production is measured in deep-inelastic $ep$ scattering at low $x$ and $Q^2$ with the H1 detector using an integrated luminosity of $44{.}2 {\rm pb}^{-1}$. Several phase space regions are selected for the three-jet analysis in order to study the underlying parton dynamics from global topologies to the more restrictive regions of forward jets close to the proton direction. The measurements of cross sections for events with at least three jets are compared to fixed order QCD predictions of ${\mathcal{O}}(\alpha_{\rm s}^2)$ and ${\mathcal{O}}(\alpha_{\rm s}^3) $ and with Monte Carlo simulation programs where higher order effects are approximated by parton showers. A good overall description is provided by the ${\mathcal{O}}(\alpha_{\rm s}^3) $ calculation. Too few events are predicted at the lowest $x \sim 10^{-4}$, especially for topologies with two forward jets. This hints to large contributions at low $x$ from initial state radiation of gluons close to the proton direction and unordered in transverse momentum. The Monte Carlo program in which gluon radiation is generated by the colour dipole model gives a good description of both the three- and the four-jet data in absolute normalisation and shape.

1 data table match query

Differential cross section as a function the jet angle THETA for events with at least 4 jets.


Three Jet production in deep inelastic scattering at HERA

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Phys.Lett.B 515 (2001) 17-29, 2001.
Inspire Record 558699 DOI 10.17182/hepdata.46712

Three-jet production is studied for the first time in deep-inelastic positron-proton scattering. The measurement carried out with the H1 detector at HERA covers a large range of four-momentum transfer squared 5 < Q^2 < 5000 GeV^2 and invariant three-jet masses 25 < M_(3jet) < 140 GeV. Jets are defined by the inclusive k_T algorithm in the Breit frame. The size of the three-jet cross section and the ratio of the three-jet to the dijet cross section R_(3/2) are described over the whole phase space by the predictions of perturbative QCD in next-to-leading order. The shapes of angular jet distributions deviate significantly from a uniform population of the available phase space but are well described by the QCD calculation.

6 data tables match query

Distribution of jet energy fraction X3 = 2E(P=4)/M(P=4_5_6) in the 3 JET centre-of-mass frame for Q**2 from 5 to 100 GeV**2.

Distribution of jet energy fraction X3 = 2E(P=4)/M(P=4_5_6) in the 3 JET centre-of-mass frame for Q**2 from 150 to 5000 GeV**2.

Distribution of jet energy fraction X4 = 2E(P=5)/M(P=4_5_6) in the 3 JET centre-of-mass frame for Q**2 from 5 to 100 GeV**2.

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The scale dependence of the hadron multiplicity in quark and gluon jets and a precise determination of C(A)/C(F).

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 449 (1999) 383-400, 1999.
Inspire Record 495414 DOI 10.17182/hepdata.49173

Data collected at the Z resonance using the DELPHI detector at LEP are used to determine the charged hadron multiplicity in gluon and quark jets as a function of a transverse momentum-like scale. The colour factor ratio, \cacf, is directly observed in the increase of multiplicities with that scale. The smaller than expected multiplicity ratio in gluon to quark jets is understood by differences in the hadronization of the leading quark or gluon. From the dependence of the charged hadron multiplicity on the opening angle in symmetric three-jet events the colour factor ratio is measured to be: C_A/C_F = 2.246 \pm 0.062 (stat.) \pm 0.080 (syst.) \pm 0.095 (theo.)

1 data table match query

Charged multiplicity in events with a hard photon, as a function of the apparent centre-of-mass energy (SQRT(S)) of the hadronic system. The errors shown are statistical only.


The dependence of dijet production on photon virtuality in e p collisions at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Loizides, J.H. ; et al.
Eur.Phys.J.C 35 (2004) 487-500, 2004.
Inspire Record 649041 DOI 10.17182/hepdata.46279

The dependence of dijet production on the virtuality of the exchanged photon, Q^2, has been studied by measuring dijet cross sections in the range 0 < Q^2 < 2000 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb^-1. Dijet cross sections were measured for jets with transverse energy E_T^jet > 7.5 and 6.5 GeV and pseudorapidities in the photon-proton centre-of-mass frame in the range -3 < eta^jet <0. The variable xg^obs, a measure of the photon momentum entering the hard process, was used to enhance the sensitivity of the measurement to the photon structure. The Q^2 dependence of the ratio of low- to high-xg^obs events was measured. Next-to-leading-order QCD predictions were found to generally underestimate the low-xg^obs contribution relative to that at high xg^obs. Monte Carlo models based on leading-logarithmic parton-showers, using a partonic structure for the photon which falls smoothly with increasing Q^2, provide a qualitative description of the data.

14 data tables match query

The measured dijet DSIG/DQ**2/DET distributions. Here ET(P=4) is the transverse energy of the highest transverse energy jet.

The measured dijet DSIG/DQ**2/DET distributions. Here ET(P=4) is the transverse energy of the highest transverse energy jet.

The measured dijet DSIG/DQ**2/DET distributions. Here ET(P=4) is the transverse energy of the highest transverse energy jet.

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The Underlying event in hard interactions at the Tevatron anti-p p collider

The CDF collaboration Acosta, D. ; Affolder, T. ; Albrow, M.G. ; et al.
Phys.Rev.D 70 (2004) 072002, 2004.
Inspire Record 647490 DOI 10.17182/hepdata.22135

For comparison of inclusive jet cross sections measured at hadron-hadron colliders to next-to-leading order (NLO) parton-level calculations, the energy deposited in the jet cone by spectator parton interactions must first be subtracted. The assumption made at the Tevatron is that the spectator parton interaction energy is similar to the ambient level measured in minimum bias events. In this paper, we test this assumption by measuring the ambient charged track momentum in events containing large transverse energy jets at $\sqrt{s}=1800$ GeV and $\sqrt{s}=630$ GeV and comparing this ambient momentum with that observed both in minimum bias events and with that predicted by two Monte Carlo models. Two cones in $\eta$--$\phi$ space are defined, at the same pseudo-rapidity, $\eta$, as the jet with the highest transverse energy ($E_T^{(1)}$), and at $\pm 90^o$ in the azimuthal direction, $\phi$. The total charged track momentum inside each of the two cones is measured. The minimum momentum in the two cones is almost independent of $E_T^{(1)}$ and is similar to the momentum observed in minimum bias events, whereas the maximum momentum increases roughly linearly with the jet $E_T^{(1)}$ over most of the measured range. This study will help improve the precision of comparisons of jet cross section data and NLO perturbative QCD predictions. %this is new The distribution of the sum of the track momenta in the two cones is also examined for five different $E_T^{(1)}$ bins. The HERWIG and PYTHIA Monte Carlos are reasonably successful in describing the data, but neither can describe completely all of the event properties.

1 data table match query

Average PT inside the max and min cone for cm energy 1800 GeV.


Tests of the standard model and constraints on new physics from measurements of fermion pair production at 189-GeV to 209-GeV at LEP

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 33 (2004) 173-212, 2004.
Inspire Record 628491 DOI 10.17182/hepdata.43174

Cross-section and angular distributions for hadronic and lepton-pair final states in e+e- collisions at centre-of-mass energies between 189 GeV and 209 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. The measurements are used to determine the electromagnetic coupling constant alphaem at LEP2 energies. In addition, the results are used together with OPAL measurements at 91-183 GeV within the S-matrix formalism to determine the gamma-Z interference term and to make an almost model-independent measurement of the Z mass. Limits on extensions to the Standard Model described by effective four-fermion contact interactions or the addition of a heavy Z boson are also presented.

1 data table match query

CM energy values.


Systematic studies of the centrality and s(NN)**(1/2) dependence of dE(T)/d mu and d N(ch)/d mu in heavy ion collisions at mid-rapidity.

The PHENIX collaboration Adler, S.S. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 71 (2005) 034908, 2005.
Inspire Record 659749 DOI 10.17182/hepdata.142940

The PHENIX experiment at RHIC has measured transverse energy and charged particle multiplicity at mid-rapidity in Au+Au collisions at sqrt(s_NN) = 19.6, 130 and 200 GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments, and experiments at lower energies. The sqrt(s_NN) dependence of dE_T/deta and dN_ch/deta per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of dE_T/deta and dN_ch/deta is similar at all measured incident energies. At RHIC energies the ratio of transverse energy per charged particle was found independent of centrality and growing slowly with sqrt(s_NN). A survey of comparisons between the data and available theoretical models is also presented.

13 data tables match query

$B$/$A$ ratio from the fit to the data.

$B$/$A$ ratio from the fit to the data.

Parameter $\alpha$ from the fit to the data.

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Systematic Study of Azimuthal Anisotropy in Cu$+$Cu and Au$+$Au Collisions at $\sqrt{s_{_{NN}}} = 62.4$ and 200 GeV

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 92 (2015) 034913, 2015.
Inspire Record 1332240 DOI 10.17182/hepdata.150018

We have studied the dependence of azimuthal anisotropy $v_2$ for inclusive and identified charged hadrons in Au$+$Au and Cu$+$Cu collisions on collision energy, species, and centrality. The values of $v_2$ as a function of transverse momentum $p_T$ and centrality in Au$+$Au collisions at $\sqrt{s_{_{NN}}}$=200 GeV and 62.4 GeV are the same within uncertainties. However, in Cu$+$Cu collisions we observe a decrease in $v_2$ values as the collision energy is reduced from 200 to 62.4 GeV. The decrease is larger in the more peripheral collisions. By examining both Au$+$Au and Cu$+$Cu collisions we find that $v_2$ depends both on eccentricity and the number of participants, $N_{\rm part}$. We observe that $v_2$ divided by eccentricity ($\varepsilon$) monotonically increases with $N_{\rm part}$ and scales as ${N_{\rm part}^{1/3}}$. The Cu$+$Cu data at 62.4 GeV falls below the other scaled $v_{2}$ data. For identified hadrons, $v_2$ divided by the number of constituent quarks $n_q$ is independent of hadron species as a function of transverse kinetic energy $KE_T=m_T-m$ between $0.1<KE_T/n_q<1$ GeV. Combining all of the above scaling and normalizations, we observe a near-universal scaling, with the exception of the Cu$+$Cu data at 62.4 GeV, of $v_2/(n_q\cdot\varepsilon\cdot N^{1/3}_{\rm part})$ vs $KE_T/n_q$ for all measured particles.

1 data table match query

$v_2$ vs. $p_T$ and $v_2$/($\epsilon * N^{1/3}_{part} * n_q$) vs. ${KE}_T$/$n_q$ for $\pi$/$K$/$p$ in Au+Au at 200 GeV, in Au+Au at 62.4 GeV, and in Cu+Cu at 200 GeV. The values of $v_2$ and $p_T$ in Au+Au at 200 GeV, in Au+Au at 62.4 GeV, and in Cu+Cu at 200 GeV are the same for as figure 14, and the values of $v_2$, $n_q$, and $KE_T$ in Au+Au at 200 GeV, in Au+Au at 62.4 GeV, and in Cu+Cu at 200 GeV are the same for as figure 18.