Intermediate mass fragments from Ar-40 + Au-197: Transition from the incomplete fusion to the participant spectator regime

Milkau, U. ; Berdermann, E. ; Berthier, B. ; et al.
Phys.Rev.C 44 (1991) 1242-1245, 1991.
Inspire Record 313914 DOI 10.17182/hepdata.26157

None

1 data table

No description provided.


Intermittency in hadronic decays of the Z0

The OPAL collaboration Akrawy, M.Z. ; Alexander, G. ; Allison, J. ; et al.
Phys.Lett.B 262 (1991) 351-361, 1991.
Inspire Record 314631 DOI 10.17182/hepdata.29397

A factorial moment analysis has been performed on the differential multiplicity distributions of hadronic final states of the Z 0 recorded with the OPAL detector at LEP. The moments of the one-dimensional rapidity and the two-dimensional rapidity versus azimuthal angle distributions are found to exhibit “intermittent” behaviour attributable to the jet structure of the events. The moments are reproduced by both parton shower and matrix element QCD based hadronisation models. No evidence for fluctuations beyond those attributable to jet structure is observed.

3 data tables

Corrected factorial moments of the rapidity distribution with respect to the sphericity axis. The errors shown are statistical only but include the statistical error onthe correction factor, added in quadrature.

Corrected factorial moments of the rapidity distribution with respect to the electron beam axis. The errors shown are statistical only but include the statistical error onthe correction factor, added in quadrature.

Corrected factorial moments of the rapidity (with respect to the sphericityaxis) versus PHI distribution. For each point the NUMBER of bins are constructe d from equal numbers of YRAP and PHI bins. The errors shown are statistical only but include the statistical error onthe correction factor, added in quadrature.


Version 2
Interpreting Reactor Antineutrino Anomalies with STEREO data

The STEREO collaboration Almazán, H. ; Bernard, L. ; Blanchet, A. ; et al.
Nature 613 (2023) 257-261, 2023.
Inspire Record 2165649 DOI 10.17182/hepdata.132368

Anomalies in past neutrino measurements have led to the discovery that these particles have non-zero mass and oscillate between their three flavors when they propagate. In the 2010's, similar anomalies observed in the antineutrino spectra emitted by nuclear reactors have triggered the hypothesis of the existence of a supplementary neutrino state that would be sterile i.e. not interacting via the weak interaction. The STEREO experiment was designed to study this scientific case that would potentially extend the Standard Model of Particle Physics. Here we present a complete study based on our full set of data with significantly improved sensitivity. Installed at the ILL (Institut Laue Langevin) research reactor, STEREO has accurately measured the antineutrino energy spectrum associated to the fission of 235U. This measurement confirms the anomalies whereas, thanks to the segmentation of the STEREO detector and its very short mean distance to the core (10~m), the same data reject the hypothesis of a light sterile neutrino. Such a direct measurement of the antineutrino energy spectrum suggests instead that biases in the nuclear experimental data used for the predictions are at the origin of the anomalies. Our result supports the neutrino content of the Standard Model and establishes a new reference for the 235U antineutrino energy spectrum. We anticipate that this result will allow to progress towards finer tests of the fundamental properties of neutrinos but also to benchmark models and nuclear data of interest for reactor physics and for observations of astrophysical or geo-neutrinos.

17 data tables

12B prediction used for the control of the energy scale. The three most intense beta decay branches of 12B have been taken into account, covering 99.94% of the total decay rate. The corresponding spectra are given in bins of 50 keV, normalized to their respective branching ratio. The [no rad. corr] notation stands for the fact that we didn't include the radiative corrections in our nominal simulation, as all radiated photons should be absorbed in the STEREO target volume. However the full effect of these corrections is included in the uncertainty of the predicted spectrum. It can be deduced from the comparison with the full calculation of the beta branches given here as well.

STEREO IBD Spectrum for phase-II and phase-III. The spectra are given in nu/day and normalized to reactor power in cm2/fission/MeV with 22 250keV-wide measured-energy bins, ranging from 1.625MeV (lower edge of lowest bin) to 7.125 MeV (upper edge of highest bin). The normalized rates (cm2/fission/MeV) are split between U5 and non-U5 components (Aluminium and Off-Equilibrium corrections).

STEREO Global Covariance Matrix for phase-II and phase-III. The matrix is given as a 44x44 matrix, with 44 bins for phase-II (bins 1-22) and phase-III (bins 23-44) corresponding to the prompt spectra with 22 250-keV bins, ranging from 1.625 to 7.125 MeV; it is expressed in (cm2/fission/MeV)².

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Intranuclear cascade percolation approach for protons and light fragments production in neon niobium reactions at 400-MeV and 800-MeV per nucleon

Montarou, G. ; Marroncle, J. ; Alard, J.P. ; et al.
Phys.Rev.C 47 (1993) 2764-2781, 1993.
Inspire Record 362233 DOI 10.17182/hepdata.26046

The results of intranuclear cascade calculations (ideal gas with two-body collisions and no mean field), complemented by a simple percolation procedure, are compared with experimental data on protons and light nuclear fragments (d, t, He3, and He4) measured in 400 and 800 MeV/nucleon Ne+Nb collisions using a large solid angle detector. The model reproduces quite well global experimental observables like nuclear fragment multiplicity distributions or production cross sections, and nuclear fragment to proton ratios. For rapidity distributions the best agreement occurs for peripheral reactions. Transverse momentum analysis confirms once again that the cascade, although being a microscopic approach, gives too small a collective flow, the best agreement being reached for Z=2 nuclear fragments. Nevertheless these comparisons are encouraging for further improvements of the model. Moreover, such an approach is easy to extend to any other models that could calculate the nucleon phase space distribution after the compression stage of the reaction, when light nuclear fragments emitted at large angles are constructed from percolation.

2 data tables

No description provided.

No description provided.


Invariant mass distributions for the pp to p p eta reaction at Q=10 MeV

Moskal, P. ; Czyżykiewicz, R. ; Czerwiński, E. ; et al.
Eur.Phys.J.A 43 (2010) 131-136, 2010.
Inspire Record 839339 DOI 10.17182/hepdata.54192

Proton-proton and proton-eta invariant mass distributions and the total cross section for the pp to pp eta reaction have been determined near the threshold at an excess energy of Q=10 MeV. The experiment has been conducted using the COSY-11 detector setup and the cooler synchrotron COSY. The determined invariant mass spectra reveal significant enhancements in the region of low proton-proton relative momenta, similarly as observed previously at higher excess energies of Q=15.5 MeV and Q= 40MeV.

3 data tables

Total cross section determined from the integral of the invariant mass distribution.

Distribution of the square of the invariant mass of the proton-proton system.

Distribution of the square of the invariant mass of the proton-eta system.


Invariant-mass distribution of jet pairs produced in association with a $W$ boson in $p \bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using the full CDF Run II data set

The CDF collaboration Aaltonen, T. ; Amerio, S. ; Amidei, D. ; et al.
Phys.Rev.D 89 (2014) 092001, 2014.
Inspire Record 1282906 DOI 10.17182/hepdata.64709

We report on a study of the dijet invariant-mass distribution in events with one identified lepton, a significant imbalance in the total event transverse momentum, and two jets. This distribution is sensitive to the possible production of a new particle in association with a $W$ boson, where the boson decays leptonically. We use the full data set of proton-antiproton collisions at 1.96 TeV center-of-mass energy collected by the Collider Detector at the Fermilab Tevatron and corresponding to an integrated luminosity of 8.9 fb$^{-1}$. The data are found to be consistent with standard-model expectations, and a 95$\%$ confidence level upper limit is set on the cross section for a $W$ boson produced in association with a new particle decaying into two jets.

2 data tables

The extracted cross section assuming that the new contribution (the excess over the expected background) has the same acceptance as that for a 140 GeV Higgs boson produced in association with a W boson.

The extracted cross section measured with a restriction on DELTAR(JET1 JET2) and assuming that the new contribution (the excess over the expected background) has the same acceptance as that for a 140 GeV Higgs boson produced in association with a W boson.


Investigation into the event-activity dependence of $\Upsilon$(nS) relative production in proton-proton collisions at $\sqrt{s} = $ 7 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 11 (2020) 001, 2020.
Inspire Record 1805867 DOI 10.17182/hepdata.95684

The ratios of the production cross sections between the excited $\Upsilon$(2S) and $\Upsilon$(3S) mesons and the $\Upsilon$(1S) ground state, detected via their decay into two muons, are studied as a function of the number of charged particles in the event. The data are from proton-proton collisions at $\sqrt{s} =$ 7 TeV, corresponding to an integrated luminosity of 4.8 fb$^{-1}$, collected with the CMS detector at the LHC. Evidence of a decrease in these ratios as a function of the particle multiplicity is observed, more pronounced at low transverse momentum $p_\mathrm{T}^{\mu\mu}$. For $\Upsilon$(nS) mesons with $p_\mathrm{T}^{\mu\mu}$ $\gt$ 7 GeV, where most of the data were collected, the correlation with multiplicity is studied as a function of the underlying event transverse sphericity and the number of particles in a cone around the $\Upsilon$(nS) direction. The ratios are found to be multiplicity independent for jet-like events. The mean $p_\mathrm{T}^{\mu\mu}$ values for the $\Upsilon$(nS) states as a function of particle multiplicity are also measured and found to grow more steeply as their mass increases.

30 data tables

The measured ratios $\Upsilon(2$S$)\,/\,\Upsilon(1$S$)$ and $\Upsilon(3$S$)\,/\,\Upsilon(1$S$)$ with $p_T(\Upsilon(n$S$))>7\,GeV$ and $|y(\Upsilon(n$S$))| < 1.2$, as a function of track multiplicity $N_{track}$

The measured ratios $\Upsilon(2$S$)\,/\,\Upsilon(1$S$)$ and $\Upsilon(3$S$)\,/\,\Upsilon(1$S$)$ with $p_T(\Upsilon(n$S$))>0\,GeV$ and $|y(\Upsilon(n$S$))| < 1.93$, as a function of track multiplicity $N_{track}$.

Mean $p_T$ values of the $\Upsilon(1$S$)$, $\Upsilon(2$S$)$, and $\Upsilon(3S)$ states with $p_T\,>\,7\,GeV$ and $|y|\,<\,1.2$ as a function of track multiplicity $N_{track}$

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Investigation of (K pi) Mass Enhancement Near 1870-MeV in the Reaction K- p --> K- pi+ n at 10-GeV/c and 16-GeV/c

The Aachen-Berlin-CERN-London-Vienna collaboration Grassler, H. ; Laven, H. ; Otter, G. ; et al.
Nucl.Phys.B 125 (1977) 189, 1977.
Inspire Record 119121 DOI 10.17182/hepdata.35408

An enhancement in the (K − π + ) mass distribution at 1871 ± 10 MeV with full width of 285 ± 40 MeV is observed in the charge-exchange reaction K − p → K − π + n at 10 and 16 GeV/ c . The energy dependence of its cross section, the shape of the differential cross section d σ /d t and the decay angular distributions are consistent with a production mechanism by pion exchange. No significant enhancement at the same mass is seen in the non-charge exchange reaction K − p → (K π ) − p. The experimental evidence is reviewed and it is suggested that there may be more than one K ∗ enhancement in the 1700–1900 mass region.

2 data tables

FOR ALL EVENTS WITH 1.7 < M(K- PI+) < 2 GEV. NO FORWARD DIP. 'THETA CUT'.

THE 14.3 GEV/C POINT IS FROM ANALYSING THE DATA OF M. SPIRO ET AL., PL 60B, 389 (1976) IN THE SAME WAY. 'THETA-CUT'.


Investigation of Elastic Electron - Deuteron Scattering in the Region of the Squared Transfer Momentum 0.36-f**-2 - 0.9-f**-2

Akimov, Yu.K. ; Arvanov, A.N. ; Badalian, G.V. ; et al.
Sov.J.Nucl.Phys. 29 (1979) 335, 1979.
Inspire Record 133089 DOI 10.17182/hepdata.18482

None

1 data table

No description provided.


Investigation of Two Photon Final States in $e^+ e^-$ Annihilation at $\sqrt{s}=34$.2-{GeV}

The CELLO collaboration Behrend, H.J. ; Chen, C. ; Fenner, H. ; et al.
Phys.Lett.B 123 (1983) 127-132, 1983.
Inspire Record 182585 DOI 10.17182/hepdata.30780

Two photon final states in e + e − annihilation have been analyzed at CM energies around 34 GeV. Good agreement with QED is observed. Lower limits for the QED cutoff parameters of Λ + > 59 GeV and Λ - > 44 GeV are determined. A search for two photons with missing energy yields an upper limit for the production of neutral particles which decay into a photon and a non-interacting particle. Constraints on the mass and the coupling strength of supersymmetric photinos are discussed.

2 data tables

Cross section for ABS(cos(theta)) <0.85.

No description provided.