Date

Production of $J / \psi$ via $\psi^{\prime}$ and $X$ Decay in 300-GeV/c Proton and $\pi^{\pm}$ Nucleon Interactions

The E705 collaboration Antoniazzi, L. ; Arenton, M. ; Cao, Z. ; et al.
Phys.Rev.Lett. 70 (1993) 383-386, 1993.
Inspire Record 336204 DOI 10.17182/hepdata.19754

The production of the χ1 and χ2 states of charmonium has been observed in 300 GeV/c π±N and pN interactions. The fraction of the total inclusive J/ψ production due to radiative χ decay has been determined to be 0.40±0.04, 0.37±0.03, and 0.30±0.04 for the π+, π−, and proton data, respectively. Total cross sections have been obtained of 131±18±14 and 188±30±21 nb/nucleon in the 300 GeV/c π−N interactions for χ1 and χ2 production. By measuring the contributions to the J/ψ production due to both ψ’ and radiative χ decay, the cross sections for direct J/ψ production have been determined to be 97±14, 102±14, and 89±12 nb/nucleon for π+, π−, and protons, respectively.

8 data tables

Fractions of total J/PSI production due to radiative CHI1 and CHI2 decays.

Fractions of total J/PSI production due to radiative CHI1 and CHI2 decays.

Fractions of total J/PSI production due to radiative CHI1 and CHI2 decays.

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Charm Meson Production in 600-GeV/c $\pi^-$ Emulsion Interactions

The Fermilab E653 collaboration Kodama, K. ; Ushida, N. ; Mokhtarani, A. ; et al.
Phys.Lett.B 284 (1992) 461-470, 1992.
Inspire Record 32383 DOI 10.17182/hepdata.29154

We present total and differential cross sections for charm mesons produced in 600 GeV/ c π - emulsion interactions. Fits to d 2 σ / dx F dp T 2 ∞ (1−| x F |) n exp (- bp T 2 ) for 676 electronically reconstructed D mesons with x F >0 give n =4.25±0.24 ( stat .)±0.23 ( syst .) and b =0.76±0.03±0.03 ( GeV / c ) -2 . The total inclusive D + and D 0 cross sections are σ ( π - N → D ± ; x F >0) = 8.66±0.46±1.96 μb nucleon and σ(π - N→D 0 D 0 ; x F >0)=22.05±1.37±4.82μb nucleonk, where a linear dependence on the mean atomic weight of the target is assumed. These results are compared to next-to-leading order QCD predictions.

2 data tables

Linear A-dependence. Different modes of the charm mesons detection were used (see text for detail). The differential cross section is fitted by the equation : D2(SIG)/D(XL)/D(PT**2) = CONST*(1-XL)**POWER*EXP(-SLOPE*PT**2).

Linear A-dependence.


Neutron - proton elastic scattering spin spin correlation parameter measurements between 500-MeV and 800-MeV. 2. C(SS) and C(LS) at forward cm angles

Shima, T. ; Hill, D. ; Johnson, K.F. ; et al.
Phys.Rev.D 47 (1993) 29-45, 1993.
Inspire Record 335383 DOI 10.17182/hepdata.22585

Results are presented for the spin-spin correlation parameters CSS and CLS for free np elastic scattering at neutron beam kinetic energies of 484, 634, 720, and 788 MeV and c.m. angles between 25° and 80°. The measurements were performed with a polarized neutron beam and a polarized proton target. These are the first measurements of this type to be reported in the forward angular region with a free polarized neutron beam. The observables CSS and CLS are both small at all energies, except for CLS at 788 MeV, which is larger than phase-shift analysis predictions by more than one standard deviation for most of the measured points.

8 data tables

No description provided.

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Coherent production of single pions and rho mesons in charged current interactions of neutrinos and anti-neutrinos on neon nuclei at the Fermilab tevatron

The E632 collaboration Willocq, S. ; Aderholz, M. ; Akbari, H. ; et al.
Phys.Rev.D 47 (1993) 2661-2674, 1993.
Inspire Record 334930 DOI 10.17182/hepdata.22725

The coherent production of π and ρ mesons in νμ (ν¯μ)-neon charged-current interactions has been studied using the Fermilab 15-foot bubble chamber filled with a heavy Ne-H2 mix and exposed to the Tevatron quadrupole triplet (anti)neutrino beam. The νμ (ν¯μ) beam had an average energy of 80 GeV (70 GeV). From a sample corresponding to approximately 28 000 charged-current interactions, net signals of (53±9) μ±π∓ coherent events and (19±7) μ±π∓π0 coherent events are extracted. For E>10 GeV, the coherent pion production cross section is determined to be (3.2±0.7)×10−38 cm2 per neon nucleus whereas the coherent ρ production cross section is (2.1±0.8)×10−38 cm2 per neon nucleus. These cross sections and the kinematical characteristics of the coherent events at |t|<0.1 GeV2 are found to be in general agreement with the predictions of a model based on the hadron dominance and, in the pion case, on the partially conserved axial-vector current hypothesis. Also discussed is the coherent production of systems consisting of three pions.

4 data tables

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An Observation of exclusive Lambda(c)+ decays into Sigma+ and mesons.

The ACCMOR collaboration Barlag, S. ; Becker, H. ; Bozek, A. ; et al.
Phys.Lett.B 283 (1992) 465-470, 1992.
Inspire Record 339920 DOI 10.17182/hepdata.29175

Using data from the NA32 experiment at CERN we have studied the Λ + c decays containing a Σ + among the decay products. The interactions of 230 GeV π − with a Cu target were analysed using a precise vertex telescope (charge-coupled devices and silicon microstrip detectors) and the ACCMOR spectrometer. We have found eleven Λ + c →Σ + π + π − , one Λ + c →Σ + K + K − , two Λ + c →Σ + K + π − and one Λ + c →Σ + π + π − π + π − decays practically without any backgroun d. We have measured the branching ratios with respect to the Λ + c →pK − π + channel.

1 data table

No description provided.


A Measurement of single and double prompt photon production at the CERN anti-p p collider

The UA2 collaboration Alitti, J. ; Ambrosini, G. ; Ansari, R. ; et al.
Phys.Lett.B 288 (1992) 386-394, 1992.
Inspire Record 336186 DOI 10.17182/hepdata.29113

A measurement of the cross-sections for single and double prompt photon production in p p interactions at s = 630 GeV is presented. The data sample corresponds to an integrated luminosity of 13.2 pb −1 . The results are in good agreement with the predictions of perturbative QCD. The signal from double prompt photon production has a statistical significance of 4.3 standard deviations.

2 data tables

There is an overall systematic error of 9 pct not included in the table.

Errors quoted include statistical and all PT dependent systematic uncertainties. There is in addition a 6.8 pct overall normalization uncertainty.


A Measurement of jet shapes in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Amidei, Dante E. ; Anway, Carol E. ; et al.
Phys.Rev.Lett. 70 (1993) 713-717, 1993.
Inspire Record 340125 DOI 10.17182/hepdata.19744

We present a measurement of jet shapes in p¯p collisions at √s =1.8 TeV at the Fermilab Tevatron using the Collider Detector at Fermilab (CDF). Qualitative agreement is seen with the predictions of recent next-to-leading [O(αs3)] calculations and with leading logarithm QCD based Monte Carlo simulations. The dependence of the jet shape on transverse energy is studied.

1 data table

No description provided.


Observation of the p wave singlet state of charmonium

Armstrong, T.A. ; Bettoni, D. ; Bharadwaj, V. ; et al.
Phys.Rev.Lett. 69 (1992) 2337-2340, 1992.
Inspire Record 338054 DOI 10.17182/hepdata.42562

We have performed a search for the 1P1 state of charmonium resonantly formed in p¯p annihilations, close to the center of gravity of the 3PJ states. We report results from the study of the J/ψ+π0 and J/ψ+2π final states. We have observed a statistically significant enhancement in the p¯+p→J/ψ+π0 cross section at √s ≃3526.2 MeV. This enhancement has the characteristics of a narrow resonance of mass, total width, and production cross section consistent with what is expected for the 1P1 state. In our search we have found no candidates for the reactions p¯+p→J/ψ+π0+π0 and p¯+p→J/ψ+π++π−.

2 data tables

No description provided.

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Proton and deuteron f2 structure functions in deep inelastic muon scattering

The New Muon collaboration Amaudruz, P. ; Arneodo, M. ; Arvidson, A. ; et al.
Phys.Lett.B 295 (1992) 159-168, 1992.
Inspire Record 338074 DOI 10.17182/hepdata.29003

The structure functions F p 2 and F d 2 measured by deep inelastic muon scattering at incident energies of 90 and 280 GeV are presented. These measurements cover a large kinematic range, 0.006⩽ x ⩽0.6 and 0.5⩽ Q 2 ⩽55GeV 2 , and include the first precise data at small x , where large scaling violations are observed. The data agree with earlier results from SLAC and BCDMS but exhibit differences with respect to those of EMC-NA2. Extrapolations to small x of recent phenomenological parton distributions are shown to disagree with the present results.

60 data tables

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A Measurement of the forward - backward charge asymmetry in hadronic decays of the Z0

The OPAL collaboration Acton, P.D. ; Alexander, G. ; Allison, J. ; et al.
Phys.Lett.B 294 (1992) 436-450, 1992.
Inspire Record 336774 DOI 10.17182/hepdata.29004

We present a measurement of the forward-backward charge asymmetry in hadronic decays of the Z 0 using data collected with the OPAL detector at LEP. The forward-backward charge asymmetry was measured using a weight function method which gave the number of forward events on a statistical basis. In a data sample of 448 942 hadronic Z 0 decays, we have observed a charge asymmetry of A h = 0.040±0.004 (stat.)±0.006 (syst.)±0.002 (B 0 B 0 mix.), taking into account the effect of B 0 B 0 mixing. In the framework of the standard model, this asymmetry corresponds to an effective weak mixing angle averaged over five quark flavours of sin 2 θ W = 0.2321 ± 0.0017 ( stat. ) ± 0.0027 ( syst. ) ± 0.0009 (B 0 B 0 mix.). The result agrees with the value obtained from the Z 0 line shape and lepton pair forward-backward asymmetry.

3 data tables

No description provided.

The second systematic error is due to the uncertainty in the correction for B.BBAR mixing which had been applied to the data.

The second systematic error is due to the uncertainty in the correction for B.BBAR mixing which had been applied to the data.