Date

Direct Photon Production From Pions and Protons at 200-{GeV}/$c$

The NA3 collaboration Badier, J. ; Bardadin-Otwinowska, M. ; Bemporad, C. ; et al.
Z.Phys.C 31 (1986) 341, 1986.
Inspire Record 219999 DOI 10.17182/hepdata.15881

Direct photon production has been studied by an experiment performed with the NA3 spectrometer at CERN, using incident negative and positive beams at 200 GeV/c interacting with an isoscalar Carbon target. Two different triggers have been used; one of them requires the photon conversion. The experiment is sensitive to direct photons produced with 3.0≦PT≦6 GeV/c and center-of-mass rapidity −0.4≦y*≦1.2. Inclusive cross sections are given for incident π± and protons, and compared with second order QCD predictions; finally an estimation of the gluon structure function of the nucleon is given.

2 data tables

Data from conversion trigger. Statistical errors only.

Data from calorimeter trigger. Statistical errors only.


Intermediate Vector Boson Properties at the {CERN} Super Proton Synchrotron Collider

The UA1 collaboration Arnison, G. ; Albrow, M.G. ; Allkofer, O.C. ; et al.
EPL 1 (1986) 327-345, 1986.
Inspire Record 219230 DOI 10.17182/hepdata.30283

The properties of a sample of 172 charged intermediate vector bosons decaying in the (eνe) channel and 16 neutral intermediate vector bosons decaying in the (e+e-) channel are described. Masses, decay widths, decay angular distributions, and production cross-sections are given; they are shown to be in excellent agreement with the expectations of the SU2 ⊗ U1 standard model. A limit is put on the number of light-neutrino types Nν ≤ 10 at 90% c.l.

2 data tables

W CROSS SECTIONS ARE GIVEN IN ARNISON ET AL., NC 44A, 1.

No description provided.


Direct Photon Pair Production From Pions and Protons at 200-{GeV}/$c$

The NA3 collaboration Badier, J. ; Bardadin-Otwinowska, M. ; Bemporad, C. ; et al.
Phys.Lett.B 164 (1985) 184-188, 1985.
Inspire Record 217947 DOI 10.17182/hepdata.30329

We present results from a direct photon pair search performed with the NA3 spectrometer, using incident positive and negative beams at 200 GeV/ c interacting with a carbon target. The experiment is sensitive to photons with p T >1.8 GeV / c and −0.4⩽y ∗ ⩽1.0 , one in each arm of the apparatus. A 3 standard deviation signal is seen in τ − and p interactions. The cross section is higher than the second order QCD calculations, but systematic errors are large.

1 data table

No description provided.


W Production Properties at the {CERN} {SPS} Collider

The UA1 collaboration Arnison, G. ; Albrow, M.G. ; Allkofer, C. ; et al.
Lett.Nuovo Cim. 44 (1985) 1-16, 1985.
Inspire Record 216595 DOI 10.17182/hepdata.37589

The production properties of a sample of 172 charged intermediate vector bosons produced at the CERN Super Proton Synchrotron Collider are described. The production cross-section, the longitudinal- and transverse-momentum distributions and the properties of hadronic jet activity produced in association with the weak bosons are in agreement with the expectations of the QCD-improved Drell-Yan mechanism.

1 data table

No description provided.


Inclusive High $p_T \pi^0$ Production From $\pi^\pm$ and Protons at 200-{GeV}/$c$

The NA3 collaboration Badier, J. ; Bardadin-Otwinowska, M. ; Bemporad, C. ; et al.
Z.Phys.C 30 (1986) 45, 1986.
Inspire Record 216588 DOI 10.17182/hepdata.15912

We have measured the inclusive cross-section for π0 production at large transverse momentum by 200 GeV/c positive and negative hadron beams on Carbon targets (2.9<PT<6 GeV/c; −0.4<y*<1.2). We used the NA3 spectrometer at the CERNSPS.

2 data tables

CONVERSION TRIGGER SELECTION.

CALORIMETER TRIGGER SELECTION.


INCLUSIVE JET PRODUCTION AT S**(1/2) = 546-GeV

The UA1 collaboration Arnison, G. ; Allkofer, O.C. ; Astbury, A. ; et al.
CERN-EP-85-116, 1985.
Inspire Record 216597 DOI 10.17182/hepdata.50065

None

1 data table

No description provided.


Comparison of Three Jet and Two Jet Cross-Sections in p anti-p Collisions at the CERN SPS p anti-p Collider

The UA1 collaboration Arnison, G. ; Allkofer, O.C. ; Astbury, A. ; et al.
Phys.Lett.B 158 (1985) 494, 1985.
Inspire Record 214736 DOI 10.17182/hepdata.30390

Results are presented on two-jet and three-jet cross sections, measured in the UA1 experiment at the CERN Super Proton Synchrotron (SPS) pp̄ Collider, at the highest available subprocess cms energies ( s ̂ >150 GeV ). Precise measurements of the two-jet angular distribution are consistent with previous results but show significant scale-breaking effects. The three-jet Dalitz plot and the three-jet angular distributions show evidence for final- and initial-state bremsstrahlung processes, in agreement with the leading-order QCD predictions. A comparison of the yield of wide-angle three-jet events with the yield of two-jet events at smaller scattering angles gives for the strong interaction coupling constant: α s ( K 3J K 2J )=0.16±0.02±0.03 at Q 2 ≈4000 GeV 2 , where the factor K 3J K 2J may plausibly be assumed to be close to unity.

2 data tables

No description provided.

No description provided.


$\psi \psi$ Production and Limits on Beauty Meson Production From 400-{GeV}/$c$ Protons

The NA3 collaboration Badier, J. ; Boucrot, J. ; Bourotte, J. ; et al.
Phys.Lett.B 158 (1985) 85, 1985.
Inspire Record 213878 DOI 10.17182/hepdata.30379

From a study of multimuon events obtained in a high luminosity proton-platinum experiment at 400 GeV/ c , we find 5 ± 4 ψψ events, which correspond to a production cross section σ ( ψψ = 27 ± 10 pb. The observed production is compared to the ψψ events previously found in the same apparatus from incoming π − ; a comparison with QCD predictions is performed, giving a good agreement with expectations from gluon-gluon fusion. Finally, using like-sign dimuon, trimuon and quadrimuon events, we give model-dependent upper limits on beauty meson production: 2 nb/nucleon for central models, 20 nb/nucleon for diffractive production.

1 data table

No description provided.


Intermediate Mass Dimuon Events at the {CERN} $p \bar{p}$ Collider at $\sqrt{s}=540$-{GeV}

The UA1 collaboration Arnison, G. ; Allkofer, O.C. ; Astbury, A. ; et al.
Phys.Lett.B 155 (1985) 442-456, 1985.
Inspire Record 213203 DOI 10.17182/hepdata.49630

We report the observation of 21 dimuon events at the CERN p p Collider with the UA1 detector. The events range in invariant dimuon mass from 2 to 22 GeV / c 2 . The properties of these events are given. The bulk of the events are consistent with heavy-flavour production (mainly b b ) with a few candidates for Drell-Yan production. There remain a few events which are difficult to interpret in terms of these processes, in particular two events with isolated, like-sign muons.

2 data tables

No description provided.

No description provided.


$D^{*\pm}$ Production in Jets at the {CERN} {SPS} Collider

The UA1 collaboration Arnison, G. ; Allkofer, O.C. ; Astbury, A. ; et al.
Phys.Lett.B 147 (1984) 222-226, 1984.
Inspire Record 203147 DOI 10.17182/hepdata.30497

We report evidence for the production of the charged D ∗ mesons in pp̄ collisions at s = 540 GeV . The search was confined to the charged particle fragments of hadronic jets, which are expected to be predominantly gluon jets in this experiment. The fragmentation function and production rate for D ∗ in jets of average transverse momentum of 28 GeV/ c are given.

1 data table

THE D*'S ARE CONSIDERED AS ARISING ONLY FROM FRAGMENTATION OF HADRONIC JETS ('GLUON' JETS). HERE THE <PT> OF THE JET IS AROUND 28 GEV THE DEFINITION OF Z IS P(D*).P(JET)/(P(JET))**2.