Wang, Jian
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Energy and Momentum Distributions of Muoproduced Hadrons

del Papa, C. ; Dorfan, David E. ; Flatte, Stanley M. ; et al.
Phys.Rev.D 15 (1977) 2425, 1977.
Inspire Record 109678 DOI 10.17182/hepdata.24649

We present inclusive distributions for final-state hadrons produced in inelastic muon-proton scattering. Over the total energy range 2<W<4.7 GeV and the momentum-transfer range 0.3<Q2<4.5 GeV2, the fractional momentum and energy distributions approximately scale. Distributions in transverse momentum display an interesting two-component behavior. They show no dependence on the virtual-photon "mass squared" Q2, and have average values typical of other hadron-initiated reactions. A comparison of our distributions with those seen in e+e− annihilation and neutrino-nucleon scattering shows agreement, in support of quark-parton fragmentation ideas. We further break these distributions down by event topology.

7 data tables
Table 1

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Table 2

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Structure Functions and Charge Ratios in Muon Nucleon Scattering

del Papa, C. ; Dorfan, David E. ; Flatte, Stanley M. ; et al.
Phys.Rev.D 17 (1978) 2843, 1978.
Inspire Record 120025 DOI 10.17182/hepdata.24430

We present the fractional energy distributions for positive and negative hadrons produced in muon-proton and muon-neutron scattering, and ensuing charge ratios for the photon fragmentation region. Data presented for a center-of-mass energy range 2.8<W<4.5 GeV and a virtual-photon mass-squared range 0.5≤Q2≤4.5 GeV2 indicate an overall equality of summed structure functions for neutron and proton targets, which exhibit approximate independence of Q2 and ω′, Implications in terms of quark-fragmentation ideas are discussed.

5 data tables
Table 1

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Table 3

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Cross-section Measurements for the Reactions $\nu p \to \mu^- \pi^+ p$ and $\nu p \to \mu^- K^+ p$ at High-Energies

Bell, J. ; Coffin, C.T. ; Diamond, R.N. ; et al.
Phys.Rev.Lett. 41 (1978) 1008, 1978.
Inspire Record 131344 DOI 10.17182/hepdata.24326

We present results for the reactions νp→μ−π+p and νp→μ−K+p at energies above 5 GeV. The average cross section for the first reaction between 15 and 40 GeV is (0.80±0.12) × 10−38 cm2 and for events with Mπ+p<1.4 GeV is (0.55±0.08) × 10−38 cm2. The ratio of the cross section for the second reaction to that for the first is 0.017±0.010.

4 data tables
Table 1

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Table 3

RAPIDITY IS MEASURED IN 'QUARK' REST FRAME DEFINED AS Y(Q)=Y(LAB)-LOG(W**2/M**2) WHERE Y(LAB)=0.5*LOG((E+PL)/(E-PL)).

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Pion Pair Production From $\gamma \gamma$ Interactions at {PEP} and the Radiative Width of the F0 Meson

The DELCO collaboration Courau, A. ; Johnson, R.P. ; Sherman, S.S. ; et al.
Phys.Lett.B 147 (1984) 227-231, 1984.
Inspire Record 202552 DOI 10.17182/hepdata.30498

Results are presented of an untagged e + e − → e + e − + π + π − experiment performed at PEP with the DELCO detector. In the invariant-mass range 0.7 ⩽ W ππ < 2.0 GeV/ c 2 , the QED e + e − background is identified and eliminated, and both the π + π − predictions and the μ + μ − and K + K − background substractions are normalized to the measurement of the e e + e − events. The results agree with a simple model of superposition and interference of the f 0 (1270) resonance, produced with helicity 2, with a Born-term continuum. From a fit of the model to the data, the radiative width of the f 0 is determined to be Γ f 0 → γγ = 2.70 ± 0.21 keV.

1 data table
Table 1

Data read from graph.


First Observation and Cross-section Measurement of $\nu_e e^- \to \nu_e e^-$

Allen, R.C. ; Bharadwaj, V. ; Brooks, G.A. ; et al.
Phys.Rev.Lett. 55 (1985) 2401, 1986.
Inspire Record 215874 DOI 10.17182/hepdata.20326

We report the first observation and cross-section measurement of νe+e−→νe+e−. Using neutrinos of energy less than 53 MeV, we observed 63±17 events consistent with ν+e−→ν+e−, of which 51±17 events are assigned to νe+e−→νe+e−. The resulting cross section, {[8.9±3.2(statistical) ±1.5(systematic)]×10−45 cm2/MeV} Eν, agrees with standard electroweak theory, rules out constructive interference between weak charged-current and neutral-current interactions, and begins to indicate the existence of interference between these two interactions.

1 data table
Table 1

No description provided.


Search for high mass narrow resonances in virtual photon photon interactions

The TPC / TWO GAMMA collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.Lett. 57 (1986) 3245-3248, 1986.
Inspire Record 239032 DOI 10.17182/hepdata.20201

We report on the first search with virtual photon-photon collisions for narrow, neutral resonances with even C parity in the mass range 4.5<W<19 GeV. The data were obtained via the process e+e−→e+e−γ*γ*→e e−+R with both the scattered e+ and e− detected. We find upper limits (95% confidence level) for the partial decay width of a resonance into two photons, ranging from 50 keV at W=4.5 GeV to 10 MeV at W=19 GeV. These limits constrain theoretical models involving neutral composite bosons.

1 data table
Table 1

No description provided.


rivet Analysis
Pion and kaon pair production in photon-photon collisions

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.Lett. 57 (1986) 404, 1986.
Inspire Record 228072 DOI 10.17182/hepdata.20204

We report measurements of the two-photon processes e+e−→e+e−π+π− and e+e−→e+e−K+K−, at an e+e− center-of-mass energy of 29 GeV. In the π+π− data a high-statistics analysis of the f(1270) results in a γγ width Γ(γγ→f)=3.2±0.4 keV. The π+π− continuum below the f mass is well described by a QED Born approximation, whereas above the f mass it is consistent with a QCD-model calculation if a large contribution from the f is assumed. For the K+K− data we find agreement of the high-mass continuum with the QCD prediction; limits on f′(1520) and θ(1720) formation are presented.

5 data tables
Table 1

Data read from graph. Additional overall systematic error 20% not included.

Table 2

Data read from graph.. Additional overall systematic error 20% not included.

Table 3

Data read from graph.. Additional overall systematic error 20% not included.. The Q**2 dependence is normalized to unity for the bin centred on Q**2 = 0.

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MEASUREMENT OF THE INCLUSIVE BRANCHING FRACTION tau- ---> tau-neutrino pi- pi0 NEUTRAL MESON(S)

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.Lett. 57 (1986) 1836, 1986.
Inspire Record 233422 DOI 10.17182/hepdata.38106

We measure an inclusive branching fraction of (13.9 ± 2.0−2.2+1.9)% for the decay τ−→ντπ−π0+nh0(n>~1), where h0 is a π0 or an η. The data sample, obtained with the time-projection-chamber detector facility at the SLAC e+e− storage ring PEP, corresponds to an integrated luminosity of 72 pb−1 at 29 GeV center-of-mass energy. The measured branching fraction is somewhat greater than the theoretical prediction and, with errors taken into account, could resolve the present difference between the inclusive and the sum of the exclusive τ± branching fractions into one charged prong.

2 data tables
Table 1

No description provided.

Table 2

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COMPARISON OF THE PARTICLE FLOW IN q anti-q g AND q anti-q gamma EVENTS IN e+ e- ANNIHILATION

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.Lett. 57 (1986) 945, 1986.
Inspire Record 230224 DOI 10.17182/hepdata.38183

We compare the particle flow in the event plane of three-jet qq¯g (quark-antiquark-gluon) events with the particle flow in radiative annihilation events qq¯γ (quark-antiquark-photon) for similar kinematic configurations. In the angular region between quark and antiquark jet, we find a significant decrease in particle density for qq¯g as compared to qq¯γ. This effect is predicted in QCD as a result of destructive interference between soft-gluon radiation from quark, antiquark, and hard gluon.

2 data tables
Table 1

No description provided.

Table 2

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Measurement of the Photon Structure Function F2 (Gamma) (x, Q**2) in the Region 0.2-GeV**2 < 7-GeV**2

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Z.Phys.C 34 (1987) 1, 1987.
Inspire Record 234578 DOI 10.17182/hepdata.15803

We present a measurement of the photon structure functionF2γ in the reactionee→eeX forQ2 in the range 0.2<Q2<7 GeV2, using 9,200 multihadron events obtained with the TPC/Two-Gamma detector at PEP. The data have been corrected for detector effects using a regularized unfolding procedure and are presented as a function ofx andQ2. The structure function shows scaling in the region 0.3<Q2<1.6 GeV2,x<0.3 and rises for higherQ2. AtQ2=5.1 GeV2 the results are compared with QCD and, within the scheme of Antoniadis and Grunberg, rather conservative bounds for the QCD scale parameter of 133±50<\(\Lambda _{\overline {{\rm M}S} } \)<268±98 MeV are obtained. A study of the final state structure shows that the rise ofF2γ is consistent with being entirely due to the pointlike component of the photon.

11 data tables
Table 1

No description provided.

Table 2

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Table 3

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