Date

Formation of Delta (980) and A2 (1320) in Photon-photon Collisions

The Crystal Ball collaboration Antreasyan, D. ; Aschman, D. ; Besset, D. ; et al.
Phys.Rev.D 33 (1986) 1847, 1986.
Inspire Record 217547 DOI 10.17182/hepdata.23518

The reaction γγ→π0η has been investigated with the Crystal Ball detector at the DESY storage ring DORIS II. Formation of δ(980) and A2(1320) has been observed with γγ partial widths Γγγ(A2)=1.14±0.20±0.2 6 keV and Γγγ(δ)B(δ→πη)=0.19±0.07 −0.07+0.10 keV.

2 data tables

No description provided.

No description provided.


EVIDENCE FOR IOTA PRODUCTION IN HIGH-ENERGY e+ e- ANNIHILATION

The JADE collaboration Bartel, W. ; Becker, L. ; Cords, D. ; et al.
DESY-85-081, 1985.
Inspire Record 220907 DOI 10.17182/hepdata.45208

None

1 data table

Background subtracted.


$D \bar{D}$ Correlations in 360-{GeV}/$c \pi^- p$ Interactions

The NA27 & LEBC-EHS collaborations Aguilar-Benitez, M. ; Allison, W.W. ; Baland, J.F. ; et al.
Phys.Lett.B 164 (1985) 404-409, 1985.
Inspire Record 216598 DOI 10.17182/hepdata.49642

Charm-charm correlation properties are studied in detail for the first time using a sample of D D pairs produced in 360 GeV/ c π − p interactions. The data are compared with various models of charm production.

1 data table

No description provided.


HADRON MULTIPLICITY VARIATION WITH Q**2 AND SCALE BREAKING OF THE HADRON DISTRIBUTIONS IN DEEP INELASTIC MUON - PROTON SCATTERING

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Phys.Lett.B 165 (1985) 222-228, 1985.
Inspire Record 217810 DOI 10.17182/hepdata.30328

Measurements are presented of the variation with Q 2 (scaling violation) of the hadron multiplicity in deep inelastic muon-proton scattering. An increase in the average multiplicity of both the charged hadrons and K 0 mesons is observed with increasing Q 2 or x Bj for fixed centre-of-mass energy W . The study of the shape of the effective fragmentation function D h ( z , W , Q 2 ) shows that the increase of the particle yield with Q 2 takes place for low z particles. The variation of the hadron distributions with Q 2 is also studied in the current fragmentation region where a decrease in multiplicity is observed. Such effects are expected from QCD.

2 data tables

No description provided.

No description provided.


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

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

No description provided.


Upper Limits of the Proton Magnetic Form-factor in the Timelike Region From $\bar{p} p \to e^+ e^-$ at the {CERN} {ISR}

The Annecy(LAPP)-CERN-Genoa-Lyon-Oslo-Rome-Strasbourg-Turin collaboration Baglin, C. ; Baird, S. ; Bassompierre, G. ; et al.
Phys.Lett.B 163 (1985) 400-403, 1985.
Inspire Record 218159 DOI 10.17182/hepdata.49639

From the measurement of e + e - pairs from the reaction p̄p→e + e - at the CERN-ISR, using an antiproton beam and a hydrogen jet target, we derived upper limits for the proton magnetic form factor in the time-like region at Q 2 ⋍8.9( GeV c ) 2 and Q 2 ⋍12.5( GeV c ) 2 .

1 data table

No description provided.


Measurement of $D$ Meson Production in 200-{GeV} $\pi^-$ Be Interactions

The ACCMOR collaboration Bailey, R. ; Belau, E.R. ; Böhringer, T. ; et al.
Z.Phys.C 30 (1986) 51, 1986.
Inspire Record 221058 DOI 10.17182/hepdata.2112

We have measured the differential and total cross sections ofD meson production in 200 GeV π−-beryllium interactions, using a sample of 48 fully reconstructed and nearly background-freeD mesons in the decay channelsK∓π±,K∓π±π± andK∓π∓π±π±. A single electron trigger has been used to select events containing a pair of charmed particles. A vertex telescope of 6 silison microstrip detectors allowed the reconstruction of tracks of charged secondaries and the reconstruction of primary and decay vertices with high precision. The ratio of branching fractions for\(\mathop {D^0 }\limits^{( - )}\to K^ \mp\pi ^ \pm\) to\(\mathop {D^0 }\limits^{( - )}\to K^ \mp\pi ^ \mp\pi ^ \pm\pi ^ \pm\), and an upper limit for\(D^0- \bar D^0 \) mixing are presented.

5 data tables

'leading' D-mesons, i.e. D-mesons, containing quarks, from PI- beam. Also AD0-mesons from. D*- decays.

'non-leading' D-mesons.

No description provided.

More…

INCLUSIVE PRODUCTION OF THE DELTA (1232) RESONANCE IN MUON - PROTON SCATTERING AT 280-GeV/c

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Nucl.Phys.B 264 (1986) 739-751, 1986.
Inspire Record 218464 DOI 10.17182/hepdata.33712

Inclusive production of the Δ (1232) resonance has been measured in 280 GeV/ c muon-proton interactions. The production of the Δ ++ as a function of the variables χ BJ , W , Q 2 , χ F and p T 2 is investigated. The average Δ ++ multiplicity is found to be smaller, by a factor of 6.2 ± 1.2, than the average multiplicity of protons. An upper limit for Δ 0 production is obtained. The net hadronic charge distribution for events with a Δ ++ is presented. The results are compared to the predictions of the Lund and Fire string models.

2 data tables

No description provided.

No description provided.


Observation of a New Charmed Meson.

The ARGUS collaboration Albrecht, H. ; Binder, U. ; Harder, G. ; et al.
Phys.Rev.Lett. 56 (1986) 549, 1986.
Inspire Record 222219 DOI 10.17182/hepdata.20225

Using the ARGUS detector at the DORIS II e+e− storage ring at DESY, we have obtained evidence for a new charmed resonance which decays into D*±(2010)π∓. The observed mass and width are 2420±6 MeV/c2 and 70±21 MeV/c2, respectively. The fragmentation function is found to be hard, as expected for a state containing a leading charm quark produced by nonresonant e+e− annihilation.

2 data tables

No description provided.

Estimated production cross section obtained by comparison with observed D*(2010) production rate.