Date

Diffractive production of rho mesons and of rho pi systems by neutrinos and anti-neutrinos on protons

The WA21 collaboration Jones, G.T. ; Jones, R.W.L. ; Kennedy, B.W. ; et al.
Z.Phys.C 58 (1993) 375-386, 1993.
Inspire Record 363176 DOI 10.17182/hepdata.14426

Evidence is presented for diffractive production of ρ-mesons and of ρπ-systems invp and\(\bar \nu p\) chargedcurrent interactions. In the (anti-)neutrino energy range 10 GeV<Ev<60 GeV the cross sections for diffractive ρ and diffractive ρπ production are found to be (0.64±0.14 (stat.)±0.08 (syst.))% and (0.28±0.08 (stat.)±0.04 (syst.))% of the charged-current cross section. The diffractive ρπ signal is consistent with being entirely due to diffractivea1 production. However, the data cannot distinguish between diffractivea1 and diffractive nonresonant ρπ production. The experimental distributions ofW, Q2,xBj andyBj for diffractive ρ and ρπ events are consistent with model predictions.

4 data tables

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Production and decay of the D(s1)+ (2536)

The CLEO collaboration Alexander, James P. ; Bebek, C. ; Berkelman, Karl ; et al.
Phys.Lett.B 303 (1993) 377-384, 1993.
Inspire Record 352823 DOI 10.17182/hepdata.47264

Using the CLEO-II detector at CESR, we have observed the D s 1 (2536) + in the decay modes D s1 + →D ∗0 K + and D ∗+ K S + , and measured its fragmentation and production ratios. Using the helicity angle distribution of the daugter D ∗0 , we obtain new evidence for the assignment of 1 + for the spin and parity of the D s 1 + . We also set upper limits on the decays D s1 + →D s ∗+ λ, D 0 K + and D + K s 0 .

2 data tables

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Diffraction dissociation in anti-p p collisions at s**(1/2) = 1.8-TeV

The E710 collaboration Amos, Norman A. ; Avila, C. ; Baker, W.F. ; et al.
Phys.Lett.B 301 (1993) 313-316, 1993.
Inspire Record 342944 DOI 10.17182/hepdata.28955

We have studied single diffraction dissociation ( p p→ p X ) in proton-antiproton collisions at √ s =1.8TeV, covering the ranges 3⪅ M X ⪅200 GeV and 0.05⪅| t |⪅0.11 (GeV/ c ) 2 . Parameterizing the production to be of the form dσ ( d t d M 2 X ) = (M 2 X ) −α exp (bt) , we obtain α = 1.13±0.07 and b = 10.5±1.8(GeV/ c ) −2 . The total single diffraction dissociation cross section is 2 σ SD =8.1±1.7 mb. Comparisons are made to previous lower energy data, and to an earlier measurement by us at the same energy.

1 data table

Total single diffraction cross section.


Dependence of spectra and cross-sections yield of proton at the energy more than 0.4-GeV at fixed angles on atomic weights of colliding nuclei in nucleus-nucleus interactions

Agakishiev, G.N. ; Bekmirzaev, R. ; Kanarek, T. ; et al.
Phys.Atom.Nucl. 56 (1993) 1397-1405, 1993.
Inspire Record 345328 DOI 10.17182/hepdata.17221

None

3 data tables

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Observation of hard scattering in photoproduction at HERA

The ZEUS collaboration Derrick, M. ; Krakauer, D. ; Magill, S. ; et al.
Phys.Lett.B 297 (1992) 404-416, 1992.
Inspire Record 339388 DOI 10.17182/hepdata.45149

We report a study of electron proton collisions at very low Q 2 , corresponding to virtual photoproduction at centre of mass energies in the range 100–295 GeV. The distribution in transverse energy of the observed hadrons is much harder than can be explained by soft processes. Some of the events show back-to-back two-jet production at the rate and with the characteristics expected from hard two-body scattering. A subset of the two-jet events have energy in the electron direction consistent with that expected from the photon remnant in resolved photon processes.

1 data table

No description provided.


A Measurement of sigma(tot) (gamma p) at s**(1/2) = 210-GeV

The ZEUS collaboration Derrick, M. ; Krakauer, D. ; Magill, S. ; et al.
Phys.Lett.B 293 (1992) 465-477, 1992.
Inspire Record 339275 DOI 10.17182/hepdata.45171

The total photoproduction cross section is determined from a measurement of electroproduction with the ZEUS detector at HERA. The Q 2 values of the virtual photons are in the range 10 −7 < Q 2 <2×10 −2 GeV 2 . The γp total cross section in the γp centre of mass energy range 186–233 GeV is 154 ± 16 (stat.) ± 32 (syst.) μ b.

1 data table

Scattered electron in range 10 to 16 GeV.


Anti-proton - proton elastic scattering at s**(1/2) = 1020-GeV

The E710 collaboration Amos, Norman A. ; Avila, C. ; Baker, W.F. ; et al.
Nuovo Cim.A 106 (1993) 123-132, 1993.
Inspire Record 338043 DOI 10.17182/hepdata.42674

The antiproton-proton small-angle elastic-scattering distribution was measured at\(\sqrt s \) GeV at the Fermilab Tevatron Collider. A fit to the nuclear-scattering distribution in the range 0.065≤|t|≤0.21 (GeV/c)2 givesb=(16.2±0.5±0.5) (GeV/c)−2 for the logarithmic slope parameter. Using the optical theorem and the luminosity from Collider parameters, we obtain σtoto(1+ρ2)1/2 =(61.7±3.7±4.4)mb.

3 data tables

No description provided.

Cross sections derived assuming RE(AMP)/IM(AMP) = 0.140, see Phys. Lett. B188, 143 (1987).

Slope was derived in the t range -0.065 < t < -0.21 (GeV/c)**2.


Determination of the number of light neutrino species

The L3 collaboration Adriani, O. ; Aguilar-Benitez, M. ; Ahlen, S. ; et al.
Phys.Lett.B 292 (1992) 463-471, 1992.
Inspire Record 339090 DOI 10.17182/hepdata.29030

We have measured the cross-section of the production of single photon events in e + e − collisions near the Z 0 resonance. For an integrated luminosity of 9.6 pb −1 , we have observed 202 single photon candidates with energy between 0.9 and 3.5 GeV in the polar angular region between 45° and 135°. Assuming that the only stable weakly interacting particles are light neutrinos with standard model couplings, we determine the number of light neutrino species to be N v = 3.14 ± 0.24 (stat.)±0.12 (syst.). This corresponds to an invisible Z 0 width of Γ inv = 524 ± 40 ± 20 MeV.

1 data table

Corrected cross section.


Search for prompt muon neutrinos in 70-GeV proton interactions with iron nuclei

Bozhko, N.I. ; Borisov, A.A. ; Bugorsky, A.P. ; et al.
IFVE-92-110, 1992.
Inspire Record 340114 DOI 10.17182/hepdata.40668

None

1 data table

The cross section per nucleon is evaluated with assumption of the linear atomic number dependence. SIG(C=NEUTRINO) and SIG(C=ANTINEUTRINO) are corresponded to the NUMU and NUMUBAR data, respectevly. CLOOP-OVER.


Measurement of the e+ e- --> b anti-b and e+ e- --> c anti-c forward backward asymmetries at the Z0 resonance

The L3 collaboration Adriani, O. ; Aguilar-Benitez, M. ; Ahlen, S. ; et al.
Phys.Lett.B 292 (1992) 454-462, 1992.
Inspire Record 339089 DOI 10.17182/hepdata.29017

We have measured the forward-backward asymmetry in e + e − → b b and e + e − → c c processes using hadronic events containing muons or electrons. The data sample corresponds to 4100000 hadronic decays of the Z 0 . From a fit to the single lepton and dilepton p and p T spectra, we determine A b b =0.086±0.015±0.007 and A c c =0.083±0.038±0.027 at the effective center-of-mass energy √ s =91.24 GeV. These measurements yield a value of the electroweak mixing angle sin 2 θ w =0.2336±0.0029 .

4 data tables

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