Albajar, C.
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Measurement of the Two Photon Reaction $\gamma \gamma \to \pi^+ \pi^- \pi^+ \pi^-$ at Large Values of $Q^2$

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 41 (1988) 353-357, 1988.
Inspire Record 250570 DOI 10.17182/hepdata.15557

The process γγ→π+π−π+π− has been investigated in reactions of the typee+e−→e+e−π+π−π+π− in the single tag mode. The range of the four momentum squared of one of the virtual photons was 0.28 GeV2/c2≦Q2≦3.6 GeV2/c2, the average being 〈Q2〉=0.92 GeV2/c2; the other photon was quasi real. The reaction is mainly described by the channels γγ→ρ0ρ0 and γγ→4π (phase space), occuring with about equal probability. TheQ2-dependence of the cross section is in agreement with the ρ form factor.

2 data tables
Table 1

Data read from graph.. Additional overall systematic error 25%.

Table 2

Data read from graph.. Additional overall systematic error 25%.. The Q**2 approx 0 datum is deduced from the earlier TASSO paper, Brandelik et al, Phys. Lett. 97B(1980)448, (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+1151> RED = 1151 </a>) on rho0 rho0 production.


A Measurement of $\pi^0$ Production at Large Transverse Momentum in $\pi^- p$, $\pi^+ p$ and $p p$ Collisions at 300-{GeV}/$c$

The NA24 collaboration De Marzo, C. ; De Palma, M. ; Favuzzi, C. ; et al.
Phys.Rev.D 36 (1987) 16, 1987.
Inspire Record 236249 DOI 10.17182/hepdata.23354

Cross sections for inclusive π0 production at large transverse momentum pT were measured in π−p, π+p, and pp collisions at 300 GeV/c. The cross-section ratio σ(π−p→π0X)/σ(π+p→π0X) was found to be consistent with unity in the pT region of 1 to 5 GeV/c. The cross-section ratio σ(π+p→π0X)/σ(pp→π0X) however is growing with increasing pT and increasing π0 c.m.-system rapidity in agreement with parton-model expectations, where the partons in the pions have on average higher momenta than in the proton.

1 data table
Table 1

THERE IS ALSO A 1 PCT UNCERTAINTY IN THE PT SCALE AND A 7 PCT UNCERTAINTY IN THE NORMALISATION.


Limit on the Decay D0 $\to e^\pm \mu^\mp$

Riles, Keith ; Dorfan, J. ; Abrams, G.S. ; et al.
Phys.Rev.D 35 (1987) 2914, 1987.
Inspire Record 236093 DOI 10.17182/hepdata.23380

We have searched for the lepton-flavor-violating decay D0→e±μ∓ in 204 pb−1 of e+e− annihilation data at Ec.m.=29 GeV from the Mark II detector. No candidates were found; we estimate an upper limit on the cross section times branching ratio of σ(e+e−→D0,D¯0; inclusive)B(D0→e±μ∓)<0.35 pb at the 90% confidence level. Simple assumptions yield the rough limit B(D0→e±μ∓)<2.1×10−3. AE.

1 data table
Table 1

No description provided.


A Measurement of Direct Photon Production at Large Transverse Momentum in $\pi^- p$, $\pi^+ p$ and $p p$ Collisions at 300-{GeV}/$c$

The NA24 collaboration De Marzo, C. ; De Palma, M. ; Favuzzi, C. ; et al.
Phys.Rev.D 36 (1987) 8, 1987.
Inspire Record 236248 DOI 10.17182/hepdata.23324

Cross sections for inclusive direct photon production in π−p, π+p, and pp collisions at 300 GeV/c are measured at transverse momenta pT up to 7 GeV/c (xT=0.6). For π−p→γX also the rapidity distribution is presented. The cross-section ratio σ(π−p→γX)/σ(π+p→γX) is found to be 1 at pT=4 GeV/c and rises with increasing pT. This observation signals the occurrence of valence-quark–antiquark annihilation. The results are in good agreement with QCD predictions.

1 data table
Table 1

THERE IS ALSO A 1 PCT UNCERTAINTY IN THE PT SCALE AND A 7 PCT UNCERTAINTY IN THE NORMALISATION.


MULTIPLICITY DISTRIBUTION OF CHARGED PARTICLES IN anti-n p AND n p INTERACTIONS AND anti-n p ANNIHILATION AT 6.1-GeV/c

The Dubna-Bucharest-Kosice-Moscow-Sofiya collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Bruncko, D. ; et al.
Sov.J.Nucl.Phys. 47 (1988) 83, 1988.
Inspire Record 239906 DOI 10.17182/hepdata.39004

None

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


A-dependence of the Charm Production Cross-section in 320-{GeV}/$c \pi^-$ Interactions

The WA78 collaboration Cobbaert, H. ; Roosen, R. ; Catanesi, M.G. ; et al.
Phys.Lett.B 191 (1987) 456-461, 1987.
Inspire Record 236083 DOI 10.17182/hepdata.30162

Using a 320 GeV c π − beam incident on three different target materials Al, Fe, and U, the A -dependence of charm production is studied by measuring the yield of prompt single muons. Parametrizing the charm cross section as σ cc ( π − A) = σ 0 Aα the measured α values are α ( μ + ) = 0.76 ± 0.08 and α ( μ − ) = 0.83 ± 0.06.

2 data tables
Table 1

No description provided.

Table 2

Numbers of events per 10**6 incident PI-.


Beauty Production at the CERN Proton - anti-Proton Collider. 1.

The UA1 collaboration Albajar, C. ; Albrow, M.G. ; Allkofer, O.C. ; et al.
Phys.Lett.B 186 (1987) 237-246, 1987.
Inspire Record 236081 DOI 10.17182/hepdata.30202

We report evidence for beauty particle production through the observation of dimuon events from proton-antiproton collisions at energies of √ s =546 GeV and √ s =630 GeV at the CERN collider. Our data indicate that semi-leptonic decays of beauty particles are the dominant source of pairs of high- p T muons. The beauty flavour creation (gg or q¯q→b¯b ) cross-section needed to explain the dimuon rate is σ{ p¯p→b¯b +X, p b T 5 GeV/c, |η|<2.0}=(1.1±0.1±0.4) μb, which is in good agreement with QCD calculations. We also observe clear signals for ϒ→μ + μ − (hidden beauty) and high- p T J/ψ→μ + μ − , well above the backgraound of continuum muon pairs from the Drell-Yan mechanism.

1 data table
Table 1

No description provided.


The Cross-section of Diffraction Dissociation at the {CERN} {SPS} Collider

The UA4 collaboration Bernard, Denis ; Bozzo, M. ; Braccini, P.L. ; et al.
Phys.Lett.B 186 (1987) 227-232, 1987.
Inspire Record 235895 DOI 10.17182/hepdata.30212

Single diffraction dissociation was measured in the reaction p¯p→p¯X at the centre-of-mass energy √ s = 546 GeV. The mass M of the system X was deduced from the pseudorapidity distribution of the observed charged tracks. The cross section of single diffraction dissociation for M 2 /s⩽0.05isσ sd =9.4 ± 0.7 mb. Comparison to the ISR data shows that σ sd increases with energy less fast than the total and the elastic cross sections.

1 data table
Table 1

No description provided.


A Study of the Emc Effect Using Neutrino and Anti-neutrino Interactions in Neon and Deuterium

The WA25 & WA59 collaborations Guy, J. ; Saitta, B. ; Apeldoorn, G.Van ; et al.
Z.Phys.C 36 (1987) 337-348, 1987.
Inspire Record 236239 DOI 10.17182/hepdata.15733

Nearly 40000 neutrino and antineutrino interactions in BEBC are compared to measure the differences between neon and deuterium in the quark and antiquark distributions and in the nucleon structure functions. The ratio of Ne to D cross sections indicates some decrease betweenx∼0.2 andx∼0.6. They distributions show there is no significant increase in the neon sea, but prefer a small decrease. Taken altogether, thex andy distributions and the measured total cross-sections indicate some change in the shape of the valence distributions. No significant dependence onA is observed for either the shape of the sea or the ratio of longitudinal to transverse cross-sections.

12 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

rivet Analysis
Measurements of Total Hadronic and Inclusive $D^*$ Cross-sections in $e^+ e^-$ Annihilations Between 3.87-{GeV} and 4.5-{GeV}

Osterheld, A. ; Hofstadter, R. ; Horisberger, R. ; et al.
SLAC-PUB-4160, 1986.
Inspire Record 238081 DOI 10.17182/hepdata.18759

None

2 data tables
Table 1

R measurement.

Table 2

D* cross sections.