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A Measurement of the Muon Pair Production in $e^+ e^-$ Annihilation at 38.3-{GeV} $\le \sqrt{s} \le$ 46.8-{GeV}

The CELLO collaboration Behrend, H.J. ; Burger, J. ; Criegee, L. ; et al.

Phys.Lett.B 191 (1987) 209-216, 1987.

Inspire Record 244835 DOI 10.17182/hepdata.30180

The e + e − → μ + μ − reaction has been studied at centre of mass energies ranging between 38.3 abd 46.8 GeV with the CELLO detector at PETRA. We present results on the cross section and the charge asymmetry for this channel. Combining all the data at the average energy 〈 s 〉=43 GeV we obtain R μμ =〈 σ μμ / σ 0 〉=0.98±0.04±0.04, 〈 A μμ 〉=(−14.1±3.7±1.0)%, where σ 0 is the QED cross section and A μμ is the charge asymmetry corrected for pure radiative effects. These results are in good agreement with the expected values of R μμ =1.01 and A μμ =−14.5% at that energy.

3 data tables

Table 1

Mu-pair cross sections.

Table 2

Corrected angular distributions with data sample divided into two energy regions with means 39 and 44 GeV and total energy region.

Table 3

Forward-backward asymmetry.

$D$ Meson Production From 400 GeV/$c p p$ Interactions

The LEBC-EHS collaboration Aguilar-Benitez, M. ; Allison, W.W.M. ; Bailly, J.L. ; et al.

Phys.Lett.B 189 (1987) 476, 1987.

Inspire Record 245101 DOI 10.17182/hepdata.12913

We have measured the inclusive production properties of D and D messons produced from pp interactions at s =27.4 GeV . The differential production cross section is well represented by the empirical form d 2 σ d x F d P 2 T = 1 2 [σ ( D / D )(n+1)b](1−|x F |) n exp (−bp 2 T ) with n=4.9 ± 0.5, b=(1.0±0.1)( GeV /c) −2 , and the inclusive D / D cross section σ ( D / D ) is (30.2±3.3) ωb. The QCD fusion model predicts D / D production which is in good agreement with our data except for the magnitude of the cross section which depends sensitively on the assumed mass of the charm quark.

11 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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STUDY OF THE RESONANCE PRODUCTION IN anti-n p INTERACTIONS AT 6.1-GeV/c

The Dubna-Moscow-Bucharest-Kosice-Sofiya collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Bruncko, D. ; et al.

Sov.J.Nucl.Phys. 47 (1988) 468, 1988.

Inspire Record 246882 DOI 10.17182/hepdata.9876

None

9 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Inclusive Pion Production in 360-{GeV}/$c p p$ Interactions

The EHS-RCBC collaboration Bailly, J.L. ; Bartl, W. ; Buschbeck, B. ; et al.

Z.Phys.C 35 (1987) 309, 1987.

Inspire Record 245413 DOI 10.17182/hepdata.17437

In a study of proton-proton interactions at$\sqrt s= 26GeV$, inclusive distributions of single pions and systems of pions of various charge combinations are presented, as well as the production ratio obtained in association with various trigger particles. The results are compared to current phenomenological models in an attempt to understand multiparticle productions in hadron collisions.

1 data table

Table 1

Search for Charmed Mesons Produced in Hadronic Interactions

Ginther, G. ; Edelstein, R.M. ; Forsyth, C.P. ; et al.

Phys.Rev.D 35 (1987) 1541-1552, 1987.

Inspire Record 252546 DOI 10.17182/hepdata.23386

The hadronic production of charmed states was studied in a two-arm spectrometer using a 205-GeV/c negative-pion beam incident upon a beryllium target. One arm, filled with dense absorber, triggered the detectors upon the passage of a muon with a moderate transverse momentum and a total momentum of at least 4 GeV/c. The other arm was an open-geometry magnetic spectrometer which had both neutral- and charged-particle identification capabilities. The apparatus, the data, and an invariant-mass-plot search for evidence of charmed-meson production through several charged-particle decay modes are described. The Kπ, Kππ, and Kπππ mass plots fail to reveal significant D-meson signals. Based upon the Kπ mass plots, the 95%-confidence upper limit on the DD¯ production cross section is found to be less than 51 μb per nucleon for the production models tested. A search for evidence of charged-D* production yields 30±16 combinations above background in association with the expected trigger muon charge. Interpreted as a D* signal, this excess corresponds to a model-dependent inclusive DD¯ production cross section of 34±18−9+14 μb per nucleon. Model-dependent upper limits on the ratio of the F to D cross sections are also presented.

4 data tables

Table 1

Uncorrelated model for charmed mesons production.

Table 2

'Correlated' model for pair of charmed mesons production.

Table 3

Uncorrelated model for D/S+- mesons production.

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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.

Charged Particle Multiplicity and Angular Distributions in Proton Emulsion Interactions at 800-{GeV}

The BATON ROUGE-CRACOW-MOSCOW-TASHKENT collaboration Abduzhamilov, A. ; Barbier, L. ; Chernova, L.P. ; et al.

Phys.Rev.D 35 (1987) 3537-3540, 1987.

Inspire Record 254225 DOI 10.17182/hepdata.3930

The interaction of 800-GeV protons in nuclear emulsion has been investigated. The multiplicities and angular distributions of charged particles emitted by both the projectile and the target nucleus have been measured for 1718 inelastic events and are compared with the data obtained in proton-emulsion collisions at 67, 200, and 400 GeV. The target excitation is found to be independent of energy while the production of secondary particles continues to increase with incident proton energy.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

Measurement of Anti-neutron Proton Total and Annihilation Cross-sections From 100-{MeV}/c to 500-{MeV}/c

The BROOKHAVEN-HOUSTON-PENNSYLVANIA STATE-RICE collaboration Armstrong, T. ; Chu, C. ; Clement, J. ; et al.

Phys.Rev.D 36 (1987) 659-673, 1987.

Inspire Record 253128 DOI 10.17182/hepdata.26943

Total and annihilation n¯p cross sections from 100 to 500 MeV/c are reported, the first such measurements with good statistics in this momentum range. These cross sections are well represented by A+B/p, where p is the incident antineutron momentum, and are in agreement with previous n¯p and p¯n measurements. A comparison of these cross sections with phenomenological potential model calculations is good overall. However, the microscopic quark model gives unsatisfactory predictions. The agreement between previous p¯p annihilation cross sections and n¯p cross sections above 300 MeV/c is excellent. The total n¯p cross section is lower than the total p¯p cross section in this momentum range. Both of these types of behavior are predicted by potential models. The anticipated availability of future p¯p data below 300 MeV/c should indicate whether these trends continue at lower momenta.

1 data table

Table 1

No description provided.