Date

A Comparison of the Energy Distributions of Hadrons Produced in Deep Inelastic Scattering of Muons on Hydrogen and Deuterium Targets

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.
Z.Phys.C 31 (1986) 175, 1986.
Inspire Record 227131 DOI 10.17182/hepdata.1817

The energy distribution of inclusive hadrons produced by 280 GeV muons on hydrogen and deuterium targets are compared. The sum of the scaled energy distributions of the positive and negative hadrons is found to be the same for the two targets. The difference of these distributions is observed to factorise inx andz and thez-dependence is found to be independent of the target type and have a form (1−z)2.1±0.2. The net charge of the hadronic jet is positive at highx even in the case when the scattering takes place on the neutron. These results are in good agreement with the expectations of the Quark Parton Model.

53 data tables

No description provided.

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No description provided.

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A Measurement of the Direct Photon Spectrum From the $\Upsilon$ (1s)

The CLEO collaboration Csorna, S.E. ; Mestayer, M.D. ; Panvini, R.S. ; et al.
Phys.Rev.Lett. 56 (1986) 1222, 1986.
Inspire Record 220652 DOI 10.17182/hepdata.20260

We have observed decays of the ϒ(1S) into hadronic final states containing high-energy photons. These are interpreted as coming from the decay ϒ(1S)→γ+gluon+gluon. We compare the shape of the observed photon energy spectrum with several theoretical predictions and deduce the value of the strong-coupling constant αs and the QCD scale parameter ΛMS― (MS― denotes the modified minimal-subtraction scheme) associated with each prediction.

2 data tables

DATA TAKEN ON THE PEAK OF THE UPSI(9460).

DATA TAKEN ON THE PEAK OF THE UPSI(9460).


Direct Photon Production From Pions and Protons at 200-{GeV}/$c$

The NA3 collaboration Badier, J. ; Bardadin-Otwinowska, M. ; Bemporad, C. ; et al.
Z.Phys.C 31 (1986) 341, 1986.
Inspire Record 219999 DOI 10.17182/hepdata.15881

Direct photon production has been studied by an experiment performed with the NA3 spectrometer at CERN, using incident negative and positive beams at 200 GeV/c interacting with an isoscalar Carbon target. Two different triggers have been used; one of them requires the photon conversion. The experiment is sensitive to direct photons produced with 3.0≦PT≦6 GeV/c and center-of-mass rapidity −0.4≦y*≦1.2. Inclusive cross sections are given for incident π± and protons, and compared with second order QCD predictions; finally an estimation of the gluon structure function of the nucleon is given.

2 data tables

Data from conversion trigger. Statistical errors only.

Data from calorimeter trigger. Statistical errors only.


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 Longitudinal Event Structure in Proton Diffractive Dissociation at the {ISR}

The R608 collaboration Smith, A.M. ; Meritet, L. ; Reyrolle, M. ; et al.
Phys.Lett.B 167 (1986) 248-254, 1986.
Inspire Record 219984 DOI 10.17182/hepdata.30272

We study the internal structure of a forward-going pπ + π − π + π − system, with invariant mass in the range 2.5-4 GeV, produced through diffractive dissociation of a beam proton at the ISR. The shape of the system, as seen in its center-of-mass, deviates strongly from isotropic phase space and possesses, rather, a longitudinal structure with a major axis along the incoming proton direction. The final state proton momentum is aligned in the direction of the incoming proton, an effect which becomes more pronounced with increasing diffractive mass.

2 data tables

Acceptance corrected distribution of momentum transfer to the diffractive (p-4pi) system. Data requested from authors.

No description provided.


Inclusive $\phi$ Production in $B$ Meson Decay

The CLEO collaboration Bortoletto, D. ; Chen, A. ; Garren, L. ; et al.
Phys.Rev.Lett. 56 (1986) 800, 1986.
Inspire Record 218314 DOI 10.17182/hepdata.20228

We have measured the inclusive branching ratio for B→φX to be 0.023±0.006±0.005. The momentum distribution of the φ mesons is compared with that expected from the cascade decays B→F→φ and B→D→φ. .AE

3 data tables

DATA SAMPLE CONSISTED OF 30.4 1/PB. DATA TAKEN ON THE PEAK OF THE UPSI(10575).

CONTINUUM DATA SAMPLE CONSISTED OF 12.8 1/PB. ENERGY JUST BELOW THE UPSI(10575).

69970 B BBAR EVENTS.


Direct Photon Pair Production From Pions and Protons at 200-{GeV}/$c$

The NA3 collaboration Badier, J. ; Bardadin-Otwinowska, M. ; Bemporad, C. ; et al.
Phys.Lett.B 164 (1985) 184-188, 1985.
Inspire Record 217947 DOI 10.17182/hepdata.30329

We present results from a direct photon pair search performed with the NA3 spectrometer, using incident positive and negative beams at 200 GeV/ c interacting with a carbon target. The experiment is sensitive to photons with p T >1.8 GeV / c and −0.4⩽y ∗ ⩽1.0 , one in each arm of the apparatus. A 3 standard deviation signal is seen in τ − and p interactions. The cross section is higher than the second order QCD calculations, but systematic errors are large.

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

1 data table

No description provided.


A STUDY OF eta FORMATION IN PHOTON-PHOTON COLLISIONS AT PEP

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Armitage, J.C. ; et al.
Phys.Rev.D 33 (1986) 844, 1986.
Inspire Record 217503 DOI 10.17182/hepdata.23508

The two-photon production of the η meson has been observed, and a value has been determined for the two-photon η decay width by a measurement of the cross section σ(e+e−→e+e−η) where η→γγ. The measurement was made with the TPC/Two-Gamma facility at the SLAC e+e− collider PEP, with an accumulated data sample of 64.5 pb−1. The η→γγ events were both triggered and detected by the pole-tip calorimeter. The measured two-photon η decay width is Γη→γγ=0.64±0.14 (statistical) ±0.13 (systematic) keV, in agreement with earlier similarly determined values.

1 data table

No description provided.