Kobayakawa, H.
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Determination of the Quark Density Ratio $d(x)/u(x)$ in the Proton

The Aachen-Bonn-CERN-Munich-Oxford collaboration Allen, P. ; Grassler, H. ; Lanske, D. ; et al.
Phys.Lett.B 103 (1981) 71-74, 1981.
Inspire Record 10562 DOI 10.17182/hepdata.31204

Data from an exposure of BEBC filled with hydrogen to a wideband neutrino beam are analysed to yield the structure function F v p 2 ( x ) for x > 0.2. Using our results in combination with data from electron-proton and muon-proton scattering, the quark density ratio d/u is determined as a function of x . The dominance u at large x is clearly seen. The results are compared with theoretical predictions.

6 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Inclusive $\rho^0$, $K^*$+- (892) and F Production in $\bar{p} p$ Interactions at 12-{GeV}/$c$

Karimaki, V. ; Kinnunen, R. ; Korkea-aho, M. ; et al.
Z.Phys.C 9 (1981) 117, 1981.
Inspire Record 164811 DOI 10.17182/hepdata.14087

Inclusive production of ϱ0,K*±(892), andf is studied in\(\bar p\)p interactions at 12 GeV/c. The inclusive cross sections for ϱ0,K*±(892), andf are found to be 6.7±0.3 mb, 1.0±0.2 mb, and 1.4±0.3 mb, respectively. The differential cross sections are presented as a function of c.m. rapidity, Feynmanx and square of the transverse momentumpT2. Comparison with the correspondingpp data shows some interesting differences which can be attributed to the\(\bar p\)p annihilation. The results are compared with the predictions of the quark fusion model.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Experimental Study of Electroweak Parameters at {PETRA} Energies (12-{GeV} $< E_{CMS} <$ 36.7-{GeV})

The MARK-J collaboration Barber, D.P. ; Becker, U. ; Bei, G.D. ; et al.
Phys.Rev.Lett. 46 (1981) 1663, 1981.
Inspire Record 164675 DOI 10.17182/hepdata.3303

We have performed a high-statistics measurement of Bhabha scattering and of the production of hadrons in electron-positron annihilation at PETRA energies (12 GeV<~s<~36.7 GeV). Combining the results with measurements of μ+μ− and τ+τ− production enables us to compare our results with electroweak theory. We find sin2θw=0.27±0.08. This is in good agreement with the value obtained from neutrino experiments which were carried out in entirely different kinematic regions.

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

ASYMMETRY WAS USED.

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A Determination of Quark Weak Couplings at {PETRA} Energies

The JADE collaboration Bartel, W. ; Cords, D. ; Dittmann, P. ; et al.
Phys.Lett.B 101 (1981) 361, 1981.
Inspire Record 164812 DOI 10.17182/hepdata.31227

Data on hadron production by e + e − annihilation at c.m. energies between 12 and 36.6 GeV have been collected using the JADE detector. They have been analysed in terms of single-photon and weak neutral-current exchange assuming production of quark-antiquark pairs with only d, u, s, c and b quarks to produce values for the quark weak neutral-current couplings. A further analysis in terms of the Glashow-Salam-Weinberg theory produced the result, sin 2 θ W = 0.22 ± 0.08 . The theory has therefore been tested in a new energy domain and within the context of the neutral weak couplings of the first, second and third generation quarks.

2 data tables
Table 1

No description provided.

Table 2

WIDTH(Z) = 2.5 GEV WAS ASSUMED. CONST(N=SIN2TW) WAS DETERMINED FROM RATIO(HADRONS/MU). FIRST ORDER QCD.


The Reaction $\gamma p \to p \pi^+ \pi^- \pi^+ \pi^-$ for Photon Energies From 25-{GeV} to 70-{GeV}

The Bonn-CERN-Ecole Poly-Glasgow-Lancaster-Manchester-Orsay-Paris-Rutherford-Sheffield collaboration Aston, D. ; Atkinson, M. ; Bailey, R. ; et al.
Nucl.Phys.B 189 (1981) 15-39, 1981.
Inspire Record 164533 DOI 10.17182/hepdata.34258

Measurements of the reaction γ p → p π + π − π + π − are presented, in which π + π − π + π − systems with masses up to 3 GeV are produced from fragmentation of the incident photon. The reaction is dominated by production of the large peak of the ϱ′(1600) meson and, at higher masses ≳2 GeV, y production of jet-like 4 π systems. The ϱ′(1600) meson is produced by a predominantly s -channel helicity conserving mechanism. At higher masses there are also indications of ϱπ peaks, of masses 1.3 GeV (the A 2 meson) and 1.75 GeV, produced with a recoiling π meson by a mechanism consistent with the Deck effect.

1 data table
Table 1

CORRECTED FOR TAILS OF BREIT-WIGNER RESONANCE USED IN FIT AND ALLOWING FOR 10 PCT BACKGROUND.


A Measurement of the Cross-Section for Four Pion Production in gamma gamma Collisions at SPEAR

Burke, D.L. ; Abrams, G.S. ; Alam, M.S. ; et al.
Phys.Lett.B 103 (1981) 153-156, 1981.
Inspire Record 165016 DOI 10.17182/hepdata.31168

We present a measurement of the cross section for the reaction e + e − → e + e − π + π − π + π − at SPEAR. This channel is found to be large and dominated by the process γγ → ϱ 0 ϱ 0 → π + π − π + π − . The cross section, which is small just above the four-pion threshold, exhibits a large enhancement near the ϱ 0 ϱ 0 threshold.

1 data table
Table 1

Axis error includes +- 0.0/0.0 contribution (THE QUOTED ERRORS INCLUDE VARIOUS SYSTEMATIC ERRORS ADDED QUADRATICALLY).


Evidence for Planar Events and a Forward Double Jet Structure in Deep Inelastic Muon Scattering

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.
Phys.Lett.B 100 (1981) 433-438, 1981.
Inspire Record 164536 DOI 10.17182/hepdata.31213

The final states of charged hadrons produced in 280 GeV μp scattering are analysed with respect to their planarity and jet structure. Distributions of p ⊥ 2 in and p ⊥ out 2 are presented. A two jet structure in the forward hemisphere is observed for events with high p ⊥ tracks are predicted by QCD models.

2 data tables
Table 1

PTIN**2 is the sum of the PTIN components squared.

Table 2

PTOUT**2 is the sum of the PTOUT components squared.


Experimental Test of the {Drell-Yan} Model in $p W \to \mu^+ \mu^- X$

Smith, S.R. ; Childress, S. ; Mockett, P.M. ; et al.
Phys.Rev.Lett. 46 (1981) 1607, 1981.
Inspire Record 164176 DOI 10.17182/hepdata.20659

We report a high-statistics study of the reaction p+W→μ++μ−+X with use of an intense 400-GeV/c proton beam, a magnetized-iron beam dump, and a wide-acceptance detector. Using data near xF=0, we have extracted the nucleon sea-quark distribution and find it to be a factor 1.6±0.3 larger than that obtained by inelastic charged-current neutrino scattering. We then compare the Drell-Yan prediction with our data including the previously unexplored region of large xF and find excellent agreement for a wide range of μ-pair invariant mass.

6 data tables
Table 1

Dimuon mass mass distribution at XFP=0.1.

Table 2

Dimuon production for varying mass as function of XFP.

Table 3

Dimuon production for varying mass as function of XFP.

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Study of Particle Ratios in Single and Double Pion Production in $P P$ Interactions at 405-{GeV}/c

Suzuki, A. ; Fukawa, M. ; Kichimi, H. ; et al.
Phys.Rev.D 24 (1981) 605-611, 1981.
Inspire Record 171446 DOI 10.17182/hepdata.4382

We present results on inclusive study of particle production ratios in 405-GeV/c pp interactions from a Fermilab experiment using the 30-in. hydrogen bubble chamber. Single- and double-pion ratios π+π−, π+π−π−π−, and π+π−π+π+ as a function of the Feynman variable x are presented. From these analyses, it is shown that the quark-recombination picture seems to work well for particle production in the fragmentation region. The data on π+π− ratios in association with a leading π± or Λ are compared with each other and also with the π+π−π−π− ratio. These results further support a prediction of the quark-recombination model.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Production of Vector and Tensor Mesons in Proton Proton Collisions at $\sqrt{s}=52$.5-{GeV}

The Annecy(LAPP)-CERN-College de France-Dortmund-Heidelberg-Warsaw collaboration Drijard, D. ; Fischer, H.G. ; Geist, Walter M. ; et al.
Z.Phys.C 9 (1981) 293, 1981.
Inspire Record 164535 DOI 10.17182/hepdata.14085

Inclusive production of ϱ0,f, andg0 mesons and ofKs0,K*0 (892), ϕ andK*0(1430)mesons has been measured at ∼2.6 and ∼1.1 GeV/c in proton-proton interactions at\(\sqrt s= 52.5\) GeV. The negative particle from the two-body decays of these resonances were identified by a threshold Cerenkov counter and used for triggering. Starting from the measured differential cross section, total inclusive cross sections for the vector and tensor mesons were determined using various parametrizations for they andpT dependence of the differential cross section. The experimental results are discussed in the framework of production models based on the parton picture. The strangeness suppresion factor λ=(0.30±0.10) due toSU(3) symmetry breaking of the quark sea is derived.

1 data table
Table 1

No description provided.