Date

Comparison of eta and eta' production in the p p --> p p eta (eta') reactions near threshold.

Hibou, F. ; Bing, O. ; Boivin, M. ; et al.
Phys.Lett.B 438 (1998) 41-46, 1998.
Inspire Record 466930 DOI 10.17182/hepdata.28154

The total cross section of the pp -> pp eta' reaction has been measured at two energies near threshold by detecting the final protons in a magnetic spectrometer. The values obtained are about a factor of 70 less than for the corresponding eta production, in good agreement with the predictions of a one-pion-exchange model.

2 data tables match query

Axis error includes +- 10/10 contribution (Overall normalization error already included).

Axis error includes +- 10/10 contribution (Overall normalization error already included).


Search for multi - baryonic resonances in the anti-p + d ---> pi- + X reaction

Aslanides, E. ; Benabdelouahed, D. ; Bergdolt, A.M. ; et al.
Nucl.Phys.A 528 (1991) 608-620, 1991.
Inspire Record 323124 DOI 10.17182/hepdata.36714

The reaction p + d → π − + X has been studied at Saturne at 1.45, 2.10 and 2.70 GeV, using the spectrometer SPES III. The analysing power and the differential cross sections show no evidence for narrow structures which could be interpreted as a resonance in the three baryon system. At the lowest incident energy, the shapes of the experimental cross sections are well reproduced by phase-space distributions.

1 data table match query

Axis error includes +- 0.0/0.0 contribution (?////).


Near-threshold production of omega mesons in the p p --> p p omega reaction.

Hibou, F. ; Bing, O. ; Boivin, M. ; et al.
Phys.Rev.Lett. 83 (1999) 492-495, 1999.
Inspire Record 496452 DOI 10.17182/hepdata.40430

The total cross section for omega production in the pp -> pp omega reaction has been measured at five c.m. excess energies from 3.8 to 30 MeV. The energy dependence is easily understood in terms of a strong proton-proton final state interaction combined with a smearing over the width of the state. The ratio of near-threshold phi and omega production is consistent with the predictions of a one-pion-exchange model and the degree of violation of the OZI rule is similar to that found in the pi-p -> n omega/phi reactions.

1 data table match query

Axis error includes +- 0.0/0.0 contribution (?////Not given separately).


eta-helium quasi-bound states.

Willis, N. ; Le Bornec, Y. ; Zghiche, A. ; et al.
Phys.Lett.B 406 (1997) 14-19, 1997.
Inspire Record 441131 DOI 10.17182/hepdata.40436

The cross section and tensor analysing power t_20 of the d\vec{d}->eta 4He reaction have been measured at six c.m. momenta, 10 < p(eta) < 90 MeV/c. The threshold value of t_20 is consistent with 1/\sqrt{2}, which follows from parity conservation and Bose symmetry. The much slower momentum variation observed for the reaction amplitude, as compared to that for the analogous pd->eta 3He case, suggests strongly the existence of a quasi-bound state in the eta-4He system and optical model fits indicate that this probably also the case for eta-3He.

1 data table match query

The spin-averaged amplitude squared is defined as follows: ABS(AMP)**2 = (P_deut/P_eta)*D(SIG)/D(OMEGA) and obtained by assuming the angular distributions to be isotropic. The errors in this quantity includes a contribution from Delta(P_eta). The statistical error of about 2% are added quadratically to the systemat ic error.


Study of the Reaction d (p, pi+) t at t(p) = 410-MeV, 605-MeV and 809-MeV

Aslanides, E. ; Bertini, R. ; Bing, O. ; et al.
Phys.Rev.Lett. 39 (1977) 1654-1656, 1977.
Inspire Record 126515 DOI 10.17182/hepdata.20981

Pion production on a CD2 target has been measured using the high-resolution magnetic spectrometer SPES I. Differential cross sections for the reaction D(p, π+)T have been determed at Tp=410, 605, and 809 MeV. The present data, together with previous results establish a complete angular distribution of the reaction D(p, π+)T at ∼ 600 MeV and the energy dependence of the differential cross section for this reaction at several constant momentum transfers.

2 data tables match query

No description provided.

No description provided.


Total cross-section of the p p ---> p p eta reaction near threshold

Bergdolt, A.M. ; Bergdolt, G. ; Bing, O. ; et al.
Phys.Rev.D 48 (1993) R2969-R2973, 1993.
Inspire Record 364575 DOI 10.17182/hepdata.22579

The pp→ppη reaction is studied at energies near the η production threshold. The total cross sections at nominal machine energies of 1260, 1265, and 1300 MeV are 90±15, 790±120, and 3460±690 nb, respectively. None of the existing perturbative model calculations reproduces the energy dependence, which deviates strongly from phase space. This suggests that the cross section is enhanced in the near vicinity of the production threshold by a large η−pp scattering length.

1 data table match query

No description provided.


Near-threshold eta production in the p d --> p d eta reaction.

Hibou, F. ; Wilkin, Colin ; Bergdolt, A.M. ; et al.
Eur.Phys.J.A 7 (2000) 537-541, 2000.
Inspire Record 523315 DOI 10.17182/hepdata.43410

The total cross section of the p d -> p d eta reaction has been measured at two energies near threshold by detecting the final proton and deuteron in a magneti spectrometer. The values are somewhat larger than expected on the basis of two simple theoretical estimates.

1 data table match query

The first quoted error includes statistical and normalization uncertainties, the scond is that induced by the uncertainty in the excess energy.


Search for Anti-proton - Nucleus States With ($\bar{p}$, $p$) Reactions

Garreta, D. ; Birien, P. ; Bruge, G. ; et al.
Phys.Lett.B 150 (1985) 95-99, 1985.
Inspire Record 203156 DOI 10.17182/hepdata.49641

We have studied (p̄, p) reactions on 12 C , 63 Cu, and 209 Bi to search for possible nuclear states formed ny antiprotons and nuclei. The experiments used the 180 MeV antiproton beam from LEAR, and the high-resolution magnetic spectrometer, SPES II, to detect the outgoing protons. No evidence of antiproton-nucleus states was found. The gross features of the proton spectra are reasonably well described by intranuclear cascade model calculations, which consider proton emission following antiproton annihilations in the target nucleus.

1 data table match query

Parameters resulting from the best fits to the proton spectra with the expression D2(SIG)/D(OMEGA)/D(E) = CONST*SQRT(E)*EXP(-E/SLOPE).


Version 2
A measurement of soft-drop jet observables in $pp$ collisions with the ATLAS detector at $\sqrt{s} = 13$ TeV

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
Phys.Rev.D 101 (2020) 052007, 2020.
Inspire Record 1772062 DOI 10.17182/hepdata.92073

Jet substructure quantities are measured using jets groomed with the soft-drop grooming procedure in dijet events from 32.9 fb$^{-1}$ of $pp$ collisions collected with the ATLAS detector at $\sqrt{s} = 13$ TeV. These observables are sensitive to a wide range of QCD phenomena. Some observables, such as the jet mass and opening angle between the two subjets which pass the soft-drop condition, can be described by a high-order (resummed) series in the strong coupling constant $\alpha_S$. Other observables, such as the momentum sharing between the two subjets, are nearly independent of $\alpha_S$. These observables can be constructed using all interacting particles or using only charged particles reconstructed in the inner tracking detectors. Track-based versions of these observables are not collinear safe, but are measured more precisely, and universal non-perturbative functions can absorb the collinear singularities. The unfolded data are directly compared with QCD calculations and hadron-level Monte Carlo simulations. The measurements are performed in different pseudorapidity regions, which are then used to extract quark and gluon jet shapes using the predicted quark and gluon fractions in each region. All of the parton shower and analytical calculations provide an excellent description of the data in most regions of phase space.

252 data tables match query

Data from Fig 6a. The unfolded all-particle $log_{10}(\rho^2)$ distribution for anti-kt R=0.8 jets with $p_T$ > 300 GeV, after the soft drop algorithm is applied for $\beta$ = 0, in data. All uncertainties described in the text are shown on the data. The distributions are normalized to the integrated cross section, $\sigma$(resum), measured in the resummation region, $-3.7 < log_{10}(\rho^2) < -1.7$.

Data from Fig 6b. The unfolded charged-particle $log_{10}(\rho^2)$ distribution for anti-kt R=0.8 jets with $p_T$ > 300 GeV, after the soft drop algorithm is applied for $\beta$ = 0, in data. All uncertainties described in the text are shown on the data. The distributions are normalized to the integrated cross section, $\sigma$(resum), measured in the resummation region, $-3.7 < log_{10}(\rho^2) < -1.7$.

Data from Fig 6c. The unfolded all-particle $log_{10}(\rho^2)$ distribution for anti-kt R=0.8 jets with $p_T$ > 300 GeV, after the soft drop algorithm is applied for $\beta$ = 1, in data. All uncertainties described in the text are shown on the data. The distributions are normalized to the integrated cross section, $\sigma$(resum), measured in the resummation region, $-3.7 < log_{10}(\rho^2) < -1.7$.

More…

QCD analyses and determinations of alpha(s) in e+ e- annihilation at energies between 35-GeV and 189-GeV.

The JADE & OPAL collaborations Pfeifenschneider, P. ; Biebel, O. ; Movilla Fernandez, P.A. ; et al.
Eur.Phys.J.C 17 (2000) 19-51, 2000.
Inspire Record 513337 DOI 10.17182/hepdata.12882

We employ data taken by the JADE and OPAL experiments for an integrated QCD study in hadronic e+e- annihilations at c.m.s. energies ranging from 35 GeV through 189 GeV. The study is based on jet-multiplicity related observables. The observables are obtained to high jet resolution scales with the JADE, Durham, Cambridge and cone jet finders, and compared with the predictions of various QCD and Monte Carlo models. The strong coupling strength, alpha_s, is determined at each energy by fits of O(alpha_s^2) calculations, as well as matched O(alpha_s^2) and NLLA predictions, to the data. Matching schemes are compared, and the dependence of the results on the choice of the renormalization scale is investigated. The combination of the results using matched predictions gives alpha_s(MZ)=0.1187+{0.0034}-{0.0019}. The strong coupling is also obtained, at lower precision, from O(alpha_s^2) fits of the c.m.s. energy evolution of some of the observables. A qualitative comparison is made between the data and a recent MLLA prediction for mean jet multiplicities.

80 data tables match query

Overall result for ALPHAS at the Z0 mass from the combination of the ln R-matching results from the observables evolved using a three-loop running expression. The errors shown are total errors and contain all the statistics and systematics.

Weighted mean for ALPHAS at the Z0 mass determined from the energy evolutions of the mean values of the 2-jet cross sections obtained with the JADE and DURHAMschemes and the 3-jet fraction for the JADE, DURHAM and CAMBRIDGE schemes evaluted at a fixed YCUT.. The errors shown are total errors and contain all the statistics and systematics.

Combined results for ALPHA_S from fits of matched predicitions. The first systematic (DSYS) error is the experimental systematic, the second DSYS error isthe hadronization systematic and the third is the QCD scale error. The values of ALPHAS evolved to the Z0 mass using a three-loop evolution are also given.

More…