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EXCLUSIVE PRODUCTION OF K+ K- pi+ pi- IN PHOTON-PHOTON COLLISIONS

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Armitage, J.C. ; et al.
Phys.Rev.Lett. 54 (1985) 2564, 1985.
Inspire Record 213402 DOI 10.17182/hepdata.20345

We report a measurement of the reaction γγ→K+K−π+π− in both tagged and untagged events at PEP. The cross section rises with invariant γγ mass to about 15 nb at 2 GeV and falls slowly at higher masses. We find clear evidence for the processes γγ→φπ+π− and γγ→K*0(892)Kπ. Upper limits (95% C.L.) of 1.5 and 5.7 nb in the mass range from 1.7 to 3.7 GeV are obtained for φρ0 and K*0K¯*0 production, respectively.

8 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

Untagged sample, (non-resonant).

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CHARM PRODUCTION IN NEUTRON NUCLEON INTERACTIONS

Tzeng, L. ; Mcbride, P.L. ; Cooper, P.S. ; et al.
Phys.Rev.Lett. 55 (1985) 1172-1175, 1985.
Inspire Record 221439 DOI 10.17182/hepdata.20303

Hadronic production of charmed particles in association with muons from their semileptonic decay has been observed in a high-resolution streamer-chamber experiment performed at Fermilab. A miss-distance analysis of the pictures gives a signal of 17.3±4.7 events. Depending on the production model this corresponds to a range of neutron-nucleon cross sections from 8 to 50 μb, assuming an A23 dependence.

2 data tables
Table 1

NEUTRON BEAM : 280 GEV - AVERAGE ENERGY, PEAKED AT 320 GEV WITH FWHW OF 130 GEV.

Table 2

NEUTRON BEAM : 280 GEV - AVERAGE ENERGY, PEAKED AT 320 GEV WITH FWHW OF 130 GEV.


DECAY DISTRIBUTION OF HIGH TRANSVERSE MOMENTUM RHO MESONS

Heppelmann, S. ; Blazey, G.C. ; Baller, B. ; et al.
Phys.Rev.Lett. 55 (1985) 1824-1827, 1985.
Inspire Record 221964 DOI 10.17182/hepdata.20301

The exclusive process π−p→ρ−p has been measured at 90° c.m. with an incident pion momentum of 9.9 GeV/c. We present data on the angular dependence of the decay ρ−→π−π0. We observe a strong azimuthal dependence in the decay in the c.m. helicity frame of the ρ. Such an azimuthal dependence is not compatible with SU(6) valence-quark perturbation calculations.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


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
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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OBSERVATION OF AN ENHANCEMENT IN ANTI-P P ---> PI+ PI- AND ANTI-P P ---> K+ K- CROSS-SECTIONS AT ANTI-P MOMENTUM OF APPROXIMATELY 500-MEV/C

Tanimori, T. ; Fujii, T. ; Kageyama, T. ; et al.
Phys.Rev.Lett. 55 (1985) 1835-1838, 1985.
Inspire Record 221965 DOI 10.17182/hepdata.20293

The reactions p¯p→π+π− and K+K− have been studied at 390, 490, 590, 690, and 780 MeV/c. An enhancement of about 150 μb has been observed in the cross sections of both reactions at the same beam momentum of 490 MeV/c. If this structure is interpreted as a meson resonance, it has a mass of 1940 ± 20 MeV and a width of less than 40 MeV.

11 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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A Measurement of $\bar{p} p$ and $p p$ Elastic Scattering in the Dip Region at $\sqrt{s}=53$-{GeV}

Breakstone, A. ; Crawley, H.B. ; Dallavalle, G.M. ; et al.
Phys.Rev.Lett. 54 (1985) 2180, 1985.
Inspire Record 212895 DOI 10.17182/hepdata.20368

We have measured the differential cross section for p¯p and pp elastic scattering at s=53 GeV in the interval 0.5<|t|<4.0 (GeV/c)2 at the CERN intersecting storage rings using the split-field magnet detector. The shape of the differential cross section differs significantly between p¯p and pp scattering in the region 1.1<|t|<1.5 (GeV/c)2, with p¯p data showing a less pronounced dip structure than pp data.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


MEASUREMENTS OF SPIN CORRELATION PARAMETER A(NN) AND ANALYZING POWER AT 90-degrees FOR P (polarized) P (polarized) ---> D PI+ BETWEEN 500-MEV AND 800-MEV

Glass, G. ; Bhatia, T.S. ; Hiebert, J.C. ; et al.
Phys.Rev.Lett. 53 (1984) 1984-1987, 1984.
Inspire Record 214991 DOI 10.17182/hepdata.20423

Measurements of the spin observables ANN(90∘) and AN0(90∘) for the reaction pp→dπ+ between 500 and 800 MeV are presented and compared with previous measurements and with predictions from theories and a partial-wave analysis. These are the first available measurements of ANN above 590 MeV.

1 data table
Table 1

ANALYSING POWER IS POL.POL(NAME=AN0).


Charged Multiplicity of Hadronic Events Containing Heavy Quark Jets

Rowson, P.C. ; Trilling, G. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 54 (1985) 2580-2583, 1985.
Inspire Record 212819 DOI 10.17182/hepdata.20380

The charged-particle multiplicities of hadronic events deriving from produced bottom or charm quarks have been measured in the Mark II detector at PEP in e+e− annihilation at 29GeV. For events containing one semileptonic and one hadronic weak decay, we find multiplicities of 15.2±0.5±0.7 for bottom and 13.0±0.5±0.8 for charm. The corresponding multiplicities of charged particles accompanying the pair of heavy hadrons are 5.2±0.5±0.9 for bottom, and 8.1±0.5±0.9 for charm.

7 data tables
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Search for Spinless Bosons in $e^+ e^-$ Annihilation

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Phys.Lett.B 154 (1985) 236-242, 1985.
Inspire Record 212873 DOI 10.17182/hepdata.45223

We have measured the cross sections for e + e − → e + e − , e + e − → μ + μ − , e + e − → γγ and e + e − → hadrons in an energy scan at center of mass energies between 39.79 and 46.72 GeV in 30 MeV steps. New spinless bosons, whose existence has been postulated as a possible means to explain the anomalously large radiative width of the Z 0 found at the CERN SPS p p collider, are ruled out in the scan region. The data are used to set limits on the couplings to lepton, photon and quark pairs of bosons with masses above 46.72 GeV.

1 data table
Table 1

SIG(C=SM) is the Standard Model predicted cross section.


LOW-ENERGY ANTI-PROTON NUCLEAR ABSORPTION CROSS-SECTIONS

Ashford, V. ; Sainio, M.E. ; Sakitt, M. ; et al.
Phys.Rev.C 31 (1985) 663-665, 1985.
Inspire Record 215612 DOI 10.17182/hepdata.50305

We have studied the absorption cross section of antiprotons on Al, Cu, and Pb for T=131.6 and 193.6 MeV. These results are compared with predictions of an optical model fitted to antiproton elastic scattering data on these nuclei and are in agreement with these predictions. The cross sections have an exponential dependence on the mass number A with an exponent of approximately 0.61.

1 data table
Table 1

No description provided.