Experimental Study of Differential Cross-sections in Charged Current Neutrino and Anti-neutrinos Interactions

The CHARM collaboration Jonker, M. ; Panman, J. ; Udo, F. ; et al.
Phys.Lett.B 109 (1982) 133-140, 1982.
Inspire Record 168613 DOI 10.17182/hepdata.6668

Inclusive neutrino and antineutrino charged-current interactions were studied using the electronic detector of the CHARM Collaboration exposed to the narrow-band beam of the CERN SPS. The relative contributions of quarks and antiquarks to the neutrino cross sections were deduced from the differential cross sectionsdσ/d y . The x and Q 2 dependence of the structure functions F 2 and F 3 were measured. Scaling violations were observed, in qualitative agreement with QCD. A value of the mass scale parameter of QCD,Λ = [0.29 ± 0.12 (stat.) ± 0.10 (syst.)] GeV, was deduced in a leading-order approximation, following the method of Buras and Gaemers.

7 data tables

No description provided.

No description provided.

No description provided.

More…

Observation of a threshold effect in the anomalous J/psi suppression.

The NA50 collaboration Abreu, M.C ; Alessandro, B ; Alexa, C ; et al.
Phys.Lett.B 450 (1999) 456-466, 1999.
Inspire Record 499915 DOI 10.17182/hepdata.49189

We report on a search for a phase transition from ordinary nuclear matter to a state of deconfined quarks and gluons as predicted by lattice QCD calculations. A new measurement of charmonium production in Pb-Pb interactions at 158 GeV/ c per nucleon agrees with our previous results and confirms the anomalous J/ ψ suppression we had already observed on a significantly smaller data sample. New event selection and analysis techniques show that, for peripheral collisions, the J/ ψ cross-section per nucleon-nucleon collision agrees with the precise suppression pattern inferred from a wide range of measurements extending from p-p up to S-U collisions. As the collisions become more central, the Pb-Pb cross-section exhibits a clear departure from this normal behaviour. The onset of the anomalous J/ ψ suppression reported here is the first clear observation of a threshold effect in heavy ion collisions and can be considered as a strong indication of the production of a deconfined quark-gluon phase in central Pb-Pb collisions.

2 data tables

The J/PSI cross section is the cross section for decay to muon pairs.

The J/PSI cross section is the cross section for decay to muon pairs. The ratios in this taBLE Are obtained from the minimum bias sample of events. See text if article for details.


J / psi and Drell-Yan cross-sections in Pb Pb interactions at 158 GeV/c per nucleon

The NA50 collaboration Abreu, M.C. ; Alessandro, B. ; Alexa, C. ; et al.
Phys.Lett.B 410 (1997) 327-336, 1997.
Inspire Record 459315 DOI 10.17182/hepdata.5631

First results are reported on J ψ and Drell-Yan cross-sections in PbPb reactions at 158 GeV/ c per nucleon. The ratio of cross-sections σ J/ψ /σ DY is studied as a function of the impact parameter of the collision estimated from the measured transverse energy.

5 data tables

No description provided.

No description provided.

The Drell-Yan cross sections are taken in the mass interval 2.9 to 4.5 GeV. SIG/SIG ratio are free from most systematic errors.

More…

J/psi, psi' and Drell-Yan production in S U interactions at 200-GeV per nucleon.

The NA38 collaboration Abreu, M.C. ; Astruc, J. ; Baglin, C. ; et al.
Phys.Lett.B 449 (1999) 128-136, 1999.
Inspire Record 482405 DOI 10.17182/hepdata.49239

A detailed study of J/ ψ , ψ ′ and Drell-Yan production in S-U collisions has been performed by experiment NA38 at the CERN SPS. This paper presents production cross sections and their centrality dependence, based on the largest sample of S-U events collected by the experiment.

2 data tables

Cross sections (times decay BR into di-muons) and ratios.

Centrality dependence of the rations of J/PSI/DY and PSI(3685)/J/PSI production.


Measurement of D* meson cross sections at HERA and determination of the gluon density in the proton using NLO QCD.

The H1 collaboration Adloff, C. ; Anderson, M. ; Andreev, V. ; et al.
Nucl.Phys.B 545 (1999) 21-44, 1999.
Inspire Record 481112 DOI 10.17182/hepdata.44123

With the H1 detector at the ep collider HERA, D* meson production cross sections have been measured in deep inelastic scattering with four-momentum transfers Q^2>2 GeV2 and in photoproduction at energies around W(gamma p)~ 88 GeV and 194 GeV. Next-to-Leading Order QCD calculations are found to describe the differential cross sections within theoretical and experimental uncertainties. Using these calculations, the NLO gluon momentum distribution in the proton, x_g g(x_g), has been extracted in the momentum fraction range 7.5x10^{-4}< x_g <4x10^{-2} at average scales mu^2 =25 to 50 GeV2. The gluon momentum fraction x_g has been obtained from the measured kinematics of the scattered electron and the D* meson in the final state. The results compare well with the gluon distribution obtained from the analysis of scaling violations of the proton structure function F_2.

13 data tables

Total cross section for DIS D*+- production in the specified kinemtaic range.

DIS cross section as a function of the transverse D* momentum in the laboratory frame.

DIS cross section as a function of the transverse D* momentum in the hadronic centre-of-mass frame.

More…

Kaon production in Au + Au collisions at 11.6-A-GeV/c.

The E-802 collaboration Ahle, L. ; Akiba, Y. ; Ashktorab, K. ; et al.
Phys.Rev.C 58 (1998) 3523-3538, 1998.
Inspire Record 483011 DOI 10.17182/hepdata.25644

A systematic study of the spectra and yields of K+ and K− is reported by experiment E866 as a function of centrality in Au+Au collisions at 11.6A GeV/c. The invariant transverse spectra for both kaon species are well described by exponentials in mt, with inverse slope parameters that are largest at midrapidity and which increase with centrality. The inverse slopes of the K+ spectra are slightly larger than the inverse slopes of the K− spectra. The kaon rapidity density peaks at midrapidity with the K+ distribution wider in rapidity than K−. The integrated total yields of K+ and K− increase nonlinearly and steadily with the number of projectile participants. The yield per participant for kaons is two to three times larger than the yield from N−N collisions. This enhancement suggests that the majority of kaons in central Au+Au reactions are produced in secondary hadronic collisions. There is no evidence for an onset of additional kaon production from a possible small volume of baryon-rich quark-gluon plasma. The differences between K+ and K− rapidity distributions and transverse spectra are consistent with a lower phase space for K− production due to a higher energy threshold. These differences also exclude simple thermal models that assume emission from a common equilibrated system.

2 data tables

In this case FRAGB=NUCLEAR FRAG + PROTONS.

In this case FRAGB = NUCLEAR FRAG + PROTONS.


Diffractive dijet production at HERA

The H1 collaboration Adloff, C. ; Anderson, M. ; Andreev, V. ; et al.
Eur.Phys.J.C 6 (1999) 421-436, 1999.
Inspire Record 474949 DOI 10.17182/hepdata.44206

Interactions of the type ep -> eXY are studied, where the component X of the hadronic final state contains two jets and is well separated in rapidity from a leading baryonic system Y. Analyses are performed of both resolved and direct photoproduction and of deep-inelastic scattering with photon virtualities in the range 7.5 < Q^2 < 80 GeV^2. Cross sections are presented where Y has mass M_Y < 1.6 GeV, the squared four-momentum transferred at the proton vertex satisfies |t| < 1 GeV^2 and the two jets each have transverse momentum p^jet_T > 5 GeV relative to the photon direction in the rest frame of X. Models based on a factorisable diffractive exchange with a gluon dominated structure, evolved to a scale set by the transverse momentum p^hat_T of the outgoing partons from the hard interaction, give good descriptions of the data. Exclusive qqbar production, as calculated in perturbative QCD using the squared proton gluon density, represents at most a small fraction of the measured cross section. The compatibility of the data with a breaking of diffractive factorisation due to spectator interactions in resolved photoproduction is investigated.

6 data tables

Transverse momentum distribution for two jet production in photoproduction events (one entry per jet).

Transverse momentum distribution for two jet production in DIS events (one entry per jet).

Differential pseudo rapidity distribution in the lab frame for photoproduction data (one entry per jet).

More…

A measurement of alpha(s)(Q**2) from the Gross-Llewellyn Smith sum rule.

Kim, J.H. ; Harris, Deborah A. ; Arroyo, C.G. ; et al.
Phys.Rev.Lett. 81 (1998) 3595-3598, 1998.
Inspire Record 475039 DOI 10.17182/hepdata.19536

We extract a set of values for the Gross-Llewellyn Smith sum rule at different values of 4-momentum transfer squared ($Q^{2}$), by combining revised CCFR neutrino data with data from other neutrino deep-inelastic scattering experiments for $1 < Q^2 < 15 GeV^2/c^2$. A comparison with the order $\alpha^{3}_{s}$ theoretical predictions yields a determination of $\alpha_{s}$ at the scale of the Z-boson mass of $0.114 \pm^{.009}_{.012}$. This measurement provides a new and useful test of perturbative QCD at low $Q^2$, because of the low uncertainties in the higher order calculations.

3 data tables

No description provided.

Total GLS integral and ALPHAS for each bin in Q2. Systematic errors are correlated in different Q2 bins. The second DSYS error in ALPHAS is due to the uncertainty in the theory.

ALPHAS extrapolated to the Z0 mass. The second DSYS error is due to the uncertainty in the theory.


ZEUS results on the measurement and phenomenology of F2 at low x and low Q**2.

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Eur.Phys.J.C 7 (1999) 609-630, 1999.
Inspire Record 475922 DOI 10.17182/hepdata.44218

Measurements of the proton structure function $F_2$ for $0.6 < Q^2 < 17 {GeV}^2$ and $1.2 \times 10^{-5} < x <1.9 \times 10^{-3}$ from ZEUS 1995 shifted vertex data are presented. From ZEUS $F_2$ data the slopes $dF_2/d\ln Q^2$ at fixed $x$ and $d\ln F_2/d\ln(1/x)$ for $x < 0.01$ at fixed $Q^2$ are derived. For the latter E665 data are also used. The transition region in $Q^2$ is explored using the simplest non-perturbative models and NLO QCD. The data at very low $Q^2$ $\leq 0.65 {GeV}^2$ are described successfully by a combination of generalised vector meson dominance and Regge theory. From a NLO QCD fit to ZEUS data the gluon density in the proton is extracted in the range $3\times 10^{-5} < x < 0.7$. Data from NMC and BCDMS constrain the fit at large $x$. Assuming the NLO QCD description to be valid down to $Q^2\sim 1 {GeV}^2$, it is found that the $q\bar{q}$ sea distribution is still rising at small $x$ and the lowest $Q^2$ values whereas the gluon distribution is strongly suppressed.

15 data tables
More…

Determination of the deep inelastic contribution to the generalised Gerasimov-Drell-Hearn integral for the proton and neutron.

The HERMES collaboration Ackerstaff, K. ; Airapetian, A. ; Akopov, N. ; et al.
Phys.Lett.B 444 (1998) 531-538, 1998.
Inspire Record 476388 DOI 10.17182/hepdata.44128

The virtual photon absorption cross section differences [sigma_1/2-sigma_3/2] for the proton and neutron have been determined from measurements of polarised cross section asymmetries in deep inelastic scattering of 27.5 GeV longitudinally polarised positrons from polarised 1H and 3He internal gas targets. The data were collected in the region above the nucleon resonances in the kinematic range nu < 23.5 GeV and 0.8 GeV**2 < Q**2 < 12 GeV**2. For the proton the contribution to the generalised Gerasimov-Drell-Hearn integral was found to be substantial and must be included for an accurate determination of the full integral. Furthermore the data are consistent with a QCD next-to-leading order fit based on previous deep inelastic scattering data. Therefore higher twist effects do not appear significant.

13 data tables

Gerasimov-Drell-Hearn sum rule for proton as a function of Q2.

Gerasimov-Drell-Hearn sum rule for neutron as a function of Q2 (integral spans from Q2/2M to infinity instead of zero to infinity, see paper).

Cross section difference for the proton data. Statistical errors only.

More…