Ackerstaff, K.
Max results
Sort by Reverse order

Showing 10 of 4624 results

Date

Measurement of D*+- production and the charm contribution to F2 in deep inelastic scattering at HERA.

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Eur.Phys.J.C 12 (2000) 35-52, 2000.
Inspire Record 505056 DOI 10.17182/hepdata.43895

The production of D*+-(2010) mesons in deep inelastic scattering has been measured in the ZEUS detector at HERA using an integrated luminosity of 37 pb^-1. The decay channels D*+ -> D0 pi+(+c.c.), with D0 -> K- pi+ or D0 ->K- pi- pi+ pi+, have been used to identify the D mesons. The e+p cross section for inclusive D*+- production with 1

22 data tables
Table 1

The measured cross section for D* production. The first is derived from theK2PI final state and the second from the K4PI final state.

Table 2

The differential cross section w.r.t. Q**2 from the K2PI final state. The asymmetric errors are the quadratic sum of the statistical and systematic errors. The statistical errors are also shown separately.

Table 3

The differential cross section w.r.t. X from the K2PI final state. The asymmetric errors are the quadratic sum of the statistical and systematic errors. The statistical errors are also shown separately.

More…

Study of Z Boson Pair Production in e+ e- collisions at LEP at S**(1/2) = 189-GeV

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 465 (1999) 363-375, 1999.
Inspire Record 507739 DOI 10.17182/hepdata.49105

The pair production of Z bosons is studied using the data collected by the L3 detector at LEP in 1998 in e+e- collisions at a centre-of-mass energy of 189 GeV. All the visible final states are considered and the cross section of this process is measured to be 0.74 +0.15 -0.14 (stat.) +/- 0.04 (syst.) pb. Final states containing b quarks are enhanced by a dedicated selection and their production cross section is found to be 0.18 +0.09 -0.07 (stat.) +/- 0.02 (syst.) pb. Both results are in agreement with the Standard Model predictions. Limits on anomalous couplings between neutral gauge bosons are derived from these measurements.

4 data tables
Table 1

The total cross section. Also given is the NC02 cross section in which only two conversion diagrams are considered.

Table 2

Cross section for the individual decay channels.

Table 3

Cross section for b-quark production.

More…

Measurement of the spin-density matrix elements in exclusive electroproduction of rho0 mesons at HERA.

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Eur.Phys.J.C 12 (2000) 393-410, 2000.
Inspire Record 505172 DOI 10.17182/hepdata.24209

Exclusive electroproduction of rho^0 mesons has been measured using the ZEUS detector at HERA in two Q^2 ranges, 0.25

8 data tables
Table 1

The spin-density matrix elements obtained from the BPC low Q**2 data set.

Table 2

The spin-density matrix elements obtained from the DIS high Q**2 data set.

Table 3

The spin-density matrix elements obtained from the low Q**2 BPC data set in two W intervals.

More…

Small angle muon and bottom quark production in p anti-p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 84 (2000) 5478-5483, 2000.
Inspire Record 503949 DOI 10.17182/hepdata.42072

This Letter describes a measurement of the muon cross section originating from b quark decay in the forward rapidity range 2.4 < y(mu) < 3.2 in pbarp collisions at sqrt(s) = 1.8 TeV. The data used in this analysis were collected by the D0 experiment at the Fermilab Tevatron. We find that NLO QCD calculations underestimate b quark production by a factor of four in the forward rapidity region. A cross section measurement using muon+jet data has been included in this version of the paper.

3 data tables
Table 1

The forward muon cross section (per unit rapidity).

Table 2

The cross section for muons originating from b-quark decay.

Table 3

Integrated cross sections for muons originating from b-quark decay. The statistical and systematic errors are added in quadrature.


rivet Analysis
Measurement of the inclusive differential cross-section for Z bosons as a function of transverse momentum in anti-p p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.D 61 (2000) 032004, 2000.
Inspire Record 503361 DOI 10.17182/hepdata.42104

We present a measurement of the differential cross section as a function of transverse momentum of the Z boson in ppbar collisions at sqrt{s}=1.8 TeV using data collected by the D0 experiment at the Fermilab Tevatron Collider during 1994--1996. We find good agreement between our data and the NNLO resummation prediction and extract values of the non-perturbative parameters for the resummed prediction from a fit to the differential cross section.

1 data table
Table 1

Differential cross section in the electron channel. The errors contain both statistical and systematic error excluding the overall normalization error.


Production of xi resonances in sigma induced reactions at 345 GeV/c

The WA89 collaboration Adamovich, M.I. ; Alexandrov, Yu.A. ; Baranov, S.P. ; et al.
Eur.Phys.J.C 11 (1999) 271-278, 1999.
Inspire Record 503785 DOI 10.17182/hepdata.43497

We report on a measurement of the differential and total cross sections of inclusive production of Xi resonances in Sigma - nucleus collisions at 345 GeV/c.

5 data tables
Table 1

Feynman X distribution for producton XI(1530)0 on copper and carbon. The quoted errors are statistical.

Table 2

PT**2 distribution for XI(1530) producton on copper and carbon. The uoted errors are statistical.

Table 3

Feynman X distribution (times BR) per nucleon for XI(1820) and XI(1950) production. The quoted errors are statistical.

More…

The charge form factor of the neutron from the reaction H-2(pol.)(e(pol.),e' n)p.

Passchier, I. ; Alarcon, R. ; Bauer, T.S. ; et al.
Phys.Rev.Lett. 82 (1999) 4988-4991, 1999.
Inspire Record 504073 DOI 10.17182/hepdata.31239

We report on the first measurement of spin-correlation parameters in quasifree electron scattering from vector-polarized deuterium. Polarized electrons were injected into an electron storage ring at a beam energy of 720~MeV. A Siberian snake was employed to preserve longitudinal polarization at the interaction point. Vector-polarized deuterium was produced by an atomic beam source and injected into an open-ended cylindrical cell, internal to the electron storage ring. The spin correlation parameter A^V_{ed} was measured for the reaction \pol{2H}(\pol{e},e'n)p at a four-momentum transfer squared of 0.21 (GeV/c)^2 from which a value for the charge form factor of the neutron was extracted.

1 data table
Table 1

No description provided.


Measurement of partial-wave contributions in p p --> p p pi0.

Meyer, H.O. ; Balewski, J.T. ; Doskow, J. ; et al.
Phys.Rev.Lett. 83 (1999) 5439-5442, 1999.
Inspire Record 504512 DOI 10.17182/hepdata.31354

We report a measurement of the spin-dependent total cross section ratios delta_sigma_T/sigma_tot and delta_sigma_L/sigma_tot of the pp --> pp pi^0 reaction between 325 MeV and 400 MeV. The experiment was carried out with a polarized internal target in a storage ring. Non-vertical beam polarization was obtained by the use of solenoidal spin rotators. Near threshold, the knowledge of both spin-dependent total cross sections is sufficient to deduce the strength of certain participating partial waves, free of any model.

2 data tables
Table 1

SIG(C=T1-1) and SIG(C=T11) means opposite and parallel transverse beam and target polarizations. The same is for longitudunal (L) polarizations. SIG(C=TOT)is unpolarized total cross section.

Table 2

SIG(C=L1-1) and SIG(L=11) means opposite and parallel longitudinal beam andtarget polarizations. SIG(C=TOT) is unpolarized total cross section.


Spin correlation coefficients in p(pol.) p(pol.) --> p n pi+ from 325-MeV to 400-MeV.

Saha, Swapan K. ; Daehnick, W.W. ; Flammang, R.W. ; et al.
Phys.Lett.B 461 (1999) 175-182, 1999.
Inspire Record 504511 DOI 10.17182/hepdata.31356

The spin correlation coefficient combinations Axx + Ayy, Axx - Ayy and the analyzing powers Ay(theta) were measured for pp-->pnpi+ at beam energies of 325, 350, 375 and 400 MeV. A polarized internal atomic hydrogen target and a stored, polarized proton beam were used. These polarization observables are sensitive to contributions of higher partial waves. A comparison with recent theoretical calculations is provided.

1 data table
Table 1

No description provided.


Strange meson enhancement in Pb Pb collisions.

The NA44 collaboration Bearden, I. ; Bøggild, H. ; Boissevain, J. ; et al.
Phys.Lett.B 471 (1999) 6-12, 1999.
Inspire Record 504074 DOI 10.17182/hepdata.31360

The NA44 Collaboration has measured yields and differential distributions of K+, K-, pi+, pi- in transverse kinetic energy and rapidity, around the center-of-mass rapidity in 158 A GeV/c Pb+Pb collisions at the CERN SPS. A considerable enhancement of K+ production per pi is observed, as compared to p+p collisions at this energy. To illustrate the importance of secondary hadron rescattering as an enhancement mechanism, we compare strangeness production at the SPS and AGS with predictions of the transport model RQMD.

4 data tables
Table 1

Inverse slope paramters of the (1/MT)*DN/DMT distribution.

Table 2

Rapidity distributions for K+ and K- production.. Statistical and systematic errors added in quadrature.

Table 3

Rapidity distributions for PI+ and PI- production.. Statistical and systematic errors added in quadrature.

More…