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POLARIZATION EFFECTS IN RHO0 MESON PRODUCTION IN ANTI-PROTON PROTON INTERACTIONS AT 22.4-GEV/C, 12-GEV/C, AND 5.7-GEV/C

Batyunya, B.V. ; Boguslavsky, I.V. ; Boos, E.G. ; et al.

Phys.Rev.Lett. 55 (1985) 562-565, 1985.

Inspire Record 221353 DOI 10.17182/hepdata.20274

The ρ0-meson spin alignment is studied in p¯p interactions at 22.4 and 12 GeV/c and in the reaction p¯p→2π++2π−+neutrals at 5.7 GeV/c. An essential ρ0-meson spin alignment is observed. The values of the ρ00T element of the ρ0-meson spin-density matrix in the transversity frame are 0.56 ± 0.07, 0.53 ± 0.05, and 0.54 ± 0.04 for the above-mentioned interactions, respectively. An increase of ρ00T with ρ0 transverse momentum is obtained.

4 data tables

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Charged $D^*$ Production in $e^+ e^-$ Annihilation at 29-{GeV} and a Limit on D0 - Anti-d0 Mixing

Yamamoto, H. ; Atwood, W.B. ; Baillon, P. ; et al.

Phys.Rev.Lett. 54 (1985) 522-525, 1985.

Inspire Record 205132 DOI 10.17182/hepdata.20325

We have studied inclusive D*± production using the DELCO detector at PEP. Our technique involved kaon identification in the momentum range above 3.2 GeV/c using a threshold gas Čerenkov counter. This leads to a model-independent upper limit on D0−D¯0 mixing of 8.1% (90% confidence level). We also have measured the charm fragmentation function, which peaks at x≡PD*(Ebeam2−MD*2)12 of 0.56±0.06(stat.), and the total cross section for D* production, σ(D*±)=0.140±0.021(stat.)±0.032(syst.) nb (x>0.3, with radiative correction).

2 data tables

Table 1

No description provided.

Table 2

SYSTEMATIC ERROR DOES NOT INCLUDE THE UNCERTAINTY ON THE BRANCHING RATIOS USED.

A Study of the Inclusive $K_s^0$, $\Lambda$, $\bar{\Lambda}$ Production in Diffractive $\gamma$P Interactions

Bhadra, S. ; Appel, J.A. ; Bartlett, D.F. ; et al.

Phys.Rev.Lett. 55 (1985) 2749, 1985.

Inspire Record 217669 DOI 10.17182/hepdata.20275

We have studied inclusive KS, Λ, and Λ¯ photoproduction over the ranges 40<Eγ<170 GeV and forward produced mass 2<MF<10 GeV. We observe equal Λ and Λ¯ production rates and spectra as expected in a diffractive process where the target proton remains unaltered. We show that the fraction of hadronic events with a strange particle produced in events with forward mass MF agrees well with the same measurement in e+e− annihilation at a center-of-mass energy Ec.m.=MF. The x=2PMF distributions of these three particles in the forward-mass rest frame are compared with theoretical predictions.

1 data table

Table 1

No description provided.

Continuum Dimuon Production in anti-p W Collisions at 125-GeV/c

Anassontzis, E. ; Katsanevas, S. ; Kostarakis, P. ; et al.

Phys.Rev.Lett. 54 (1985) 2572, 1985.

Inspire Record 213694 DOI 10.17182/hepdata.20379

The cross section for the reaction p¯N→μ+μ−X with muon pairs in the mass range 4<M<9 GeV/c2 and xF>0 was measured to be σ=0.104±0.005±0.008 nb/nucleon. The distributions dσdxF and M3dσdM were compared to the QCD-improved Drell-Yan model and to calculations including first-order QCD corrections, with use of deep-inelastic structure functions. Excellent agreement with the data was obtained if the calculations were multiplied by factors of 2.45 and 1.41, respectively.

1 data table

Table 1

No description provided.

DIFFERENCES BETWEEN PROTON AND PI- INDUCED PRODUCTION OF THE CHARMONIUM CHI STATES

Bauer, Daniel A. ; Graff, T.L. ; Lukens, P.T. ; et al.

Phys.Rev.Lett. 54 (1985) 753-756, 1985.

Inspire Record 216287 DOI 10.17182/hepdata.20333

The charmonium χ states are observed in both π− and p Be interactions near 200 GeV/c via their radiative decay into J/ψ. The χ(3510) and χ(3555) are produced with roughly equal cross sections in π− collisions while the χ(3555) dominates in p collisions. Simple gluon fusion can account for χ production with incident protons but additional mechanisms are needed for incident π−.

1 data table

Table 1

No description provided.

INCLUSIVE PRODUCTION OF OMEGA- AND ANTI-OMEGA+ BY K0(L) CARBON INTERACTIONS IN THE ENERGY RANGE 80-GEV/C - 280-GEV/C

Hartouni, Edward P. ; Atiya, M.S. ; Holmes, Stephen D. ; et al.

Phys.Rev.Lett. 54 (1985) 628-630, 1985.

Inspire Record 216075 DOI 10.17182/hepdata.20341

We have measured the total cross sections of Ω− and Ω¯+ forward (xF>~0) inclusive production in KL0-carbon interactions in the range EK0=80 to 280 GeV to be 3.5±1.4 and 2.4±1.0 μb, respectively. We observe that the xF distributions for both of these states are increasing from xF=0 to xF≈0.6. The p⊥2 distributions are described as an exponential function in p⊥ with an average p⊥2 of 0.540 GeV2/c2.

1 data table

Table 1

No description provided.

Observation of a Narrow K anti-K State in J/psi Radiative Decays

The MARK-III collaboration Baltrusaitis, R.M. ; Becker, J. ; Blaylock, G. ; et al.

Phys.Rev.Lett. 56 (1986) 107, 1986.

Inspire Record 217856 DOI 10.17182/hepdata.20254

Evidence is presented for a narrow state, called ξ, in the decay modes J/ψ→γξ, ξ→K+K−, and ξ→KS0KS0. In the K+K− mode, the ξ has a mass of 2.230±0.006±0.014 GeV/c2, a width of Γ=0.026−0.016+0.020± 0.017 GeV/c2, a product branching ratio of (4.2−1.4+1.7±0.8)×10 −5, and a statistical significance of ∼4.5 standard deviations. In the KS0KS0 mode, it has a mass of 2.232±0.007±0.007 GeV/c2, a width of Γ=0.018−0.015+0.023± 0.010 GeV/c2, a product branching ratio of (3.1−1.3+1.6±0.7)×10 −5, and a statistical significance of ∼3.6 standard deviations. Limits on ξ decay to other final states are presented.

1 data table

Table 1

No description provided.

The Production of Massive Muon Pairs in $\pi^-$ Nucleus Collisions

Greenlee, H.B. ; Frisch, Henry J. ; Grosso-Pilcher, C. ; et al.

Phys.Rev.Lett. 55 (1985) 1555, 1985.

Inspire Record 17013 DOI 10.17182/hepdata.20316

We present measurements of the differential cross section for the production of massive muon pairs in 225-GeV/c π−-nucleus collisions. We have used the data between the ψ and ϒ resonances in the framework of the Drell-Yan quark-antiquark annihilation model to predict the behavior of the cross section in the high-mass (mμμ>11 GeV/c2) region. The data are consistent with this extrapolation provided that a QCD leading-logarithmic evolution is included in the structure functions.

2 data tables

Table 1

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Polarization of $\Lambda^\prime$s and $\bar{\Lambda}$-primes in $P P$, $\bar{P} P$, and $K^- P$ Interactions at 176-{GeV}/c

Gourlay, S.A. ; Melanson, H.L. ; Abolins, M.A. ; et al.

Phys.Rev.Lett. 56 (1986) 2244-2247, 1986.

Inspire Record 232417 DOI 10.17182/hepdata.20240

We have measured the polarization of Λ's in inclusive pp and K−p reactions and of Λ¯'s in p¯p interactions at a beam momentum of 176 GeV/c. Data were taken in the beam-fragmentation region with hyperon transverse momenta from 0.2 to 1.5 GeV/c. The P¯ produced Λ¯'s have the same magnitude and sign of polarization as the p-produced Λ's, whereas the Λ's from K−p interactions are more highly polarized and in the opposite direction.

3 data tables

Table 1

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