Perl, Martin L.
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The Influence of Fragmentation Models on the Determination of the Strong Coupling Constant in $e^+ e^-$ Annihilation Into Hadrons

The CELLO collaboration Behrend, H.J. ; Chen, C. ; Fenner, H. ; et al.
Nucl.Phys.B 218 (1983) 269-288, 1983.
Inspire Record 179447 DOI 10.17182/hepdata.8172

Hadronic events obtained with the CELLO detector at PETRA were compared with first-order QCD predictions using two different models for the fragmentation of quarks and gluons, the Hoyer model and the Lund model. Both models are in reasonable agreement with the data, although they do not completely reproduce the details of many distributions. Several methods have been applied to determine the strong coupling constant α S . Although within one model the value of α S varies by 20% among the different methods, the values determined using the Lund model are 30% or more larger (depending on the method used) than the values determined with the Hoyer model. Our results using the Hoyer model are in agreement with previous results based on this approach.

3 data tables
Table 1

DATA CORRECTED WITH HOYER MODEL (ALPHA-S=0.15).

Table 2

DATA CORRECTED WITH LUND MODEL (ALPHA-S=0.25).

Table 3

No description provided.


Determination of the Angular and Energy Dependence of Hard Constituent Scattering From $\pi^0$ Pair Events at the {CERN} Intersecting Storage Rings

The CERN-Columbia-Oxford-Rockefeller & CCOR collaborations Angelis, A.L.S. ; Besch, H.J. ; Blumenfeld, Barry J. ; et al.
Nucl.Phys.B 209 (1982) 284-300, 1982.
Inspire Record 179519 DOI 10.17182/hepdata.34059

We present data on proton-proton collisions, obtained at the CERN Intersecting Storage Rings, in which two roughly back-to-back π 0 's of high transverse momentum ( p T ) were produced. The angular distribution of the dipion axis relative to the collision axis is found to be independent of both the effective mass m of the dipion system and the centre-of-mass energy √ s of the proton-proton collision. The cross-sections d σ d m at the values of √ s satisfy a scaling law of the form d σ d m = G(x) m n , where x = m(π 0 , π 0 )//trs and n = 6.5 ± 0.5 . We show from our data that the leading π 0 carries most of the momentum of the scattered parton. Given this fact, the axis of the dipion system follows closely the direction of the scattered constituents, and we exploit this to determine the angular dependence of the hard-scattering subprocess. We also compare our data with the lowest order QCD predictions using structure functions as determined in deep-inelastic scattering and fragmentation functions from electron-positron annihilation.

1 data table
Table 1

No description provided.



Energy and Quantum Number Flow in $K^+ p$ and $\pi^+ p$ Interactions at 32-{GeV}/$c$ and 70-{GeV}/$c$

The Brussels-Serpukhov-Tbilisi-Genoa-Mons-Nijmegen-CERN collaboration Azhinenko, I.V. ; Belokopytov, Yu.A. ; Vorobev, A.P. ; et al.
Z.Phys.C 16 (1983) 291, 1983.
Inspire Record 181635 DOI 10.17182/hepdata.10881

Energy, charge and strangeness flow inK+p interactions at 32 and 70 GeV/c, and π+p interactions at 32 GeV/c are studied in terms of the angular variable λ=|x|/pT. The data ondQ/dλ anddE/dλ show only a weak indication of scale breaking between 32 and 70 GeV/c. For inclusive “non-diffractive”, inclusive “diffractive” and exclusive “non-diffractive” jets, the fraction of charge in any angular region ΔΩ away from the central region is found to be proportional to the energy fraction in the same interval. The data ondQ/dE versus λ are compatible with some versions of dual-sheet models and agree also with the LUND Monte-Carlo model. The data are also compared with\(v(\bar v)p\) interactions in BEBC. In exclusive channels the average ratiodQ/dS=0.78±0.04 is consistent, in the framework of fragmentation models, with a larger probability for the fragmentation of the\(\bar s\)-valence quark than theu-valence quark in theK+-meson.

16 data tables
Table 1

CHARGE FLOW IN NONDIFFRACTIVE PROTON-LIKE AND KAON-LIKE JETS.

Table 2

CHARGE FLOW IN NONDIFFRACTIVE PROTON-LIKE AND KAON-LIKE JETS.

Table 3

CHARGE FLOW IN NONDIFFRACTIVE PROTON-LIKE AND KAON-LIKE JETS.

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Observation of Baryons With High Transverse Momenta in $p$, $d$, He and C Nuclear Interactions With Tantalum Nuclei at 4.2-{GeV}/$c$

Akhababian, N. ; Baatar, Ts. ; Baldin, A.M. ; et al.
Sov.J.Nucl.Phys. 37 (1983) 559, 1983.
Inspire Record 180913 DOI 10.17182/hepdata.9923

None

10 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Observation of a Parity Violation in Cesium

Bouchiat, M.A. ; Guena, J. ; Hunter, L. ; et al.
Phys.Lett.B 117 (1982) 358, 1982.
Inspire Record 180105 DOI 10.17182/hepdata.30837

We have measured a parity violation in the 6S–7S transition of Cs in an electric field. Our result is Im E 1 pv β = -1.34 ± 0.22 ( rms statistical deviation ) ± ∼0.11 ( systematic uncertainty ) mV cm; E 1 pv is the parity violating electric dipole amplitude, ß is the vector polarizability. This result is consistent with the Weinberg-Salam prediction.

1 data table
Table 1

(7s)2S1/2:F=4 --> (6s)2S1/2:F=4 transition.


Pion - Proton Elastic Scattering at 20-{GeV}/$c$ and 50-{GeV}/$c$ Incident Momenta in the Momentum Transfer Range 0.7-{GeV}/$c < sqrt{t}< 8$-{GeV}/$c$

The Annecy(Lapp)-CERN-Bohr Inst-Genoa-Oslo-London collaboration Asad, Z. ; Baglin, C. ; Benso, S. ; et al.
Phys.Lett.B 118 (1982) 442, 1982.
Inspire Record 179091 DOI 10.17182/hepdata.30852

Measurements of the differential elastic cross sections for π − p scattering at incident momenta of 20 and 50 GeV c and π + p at 50 GeV c in the momentum transfer range 0.7 < |t|; < 8.0 ( GeV c ) 2 are presented. The data are compared with various models of elastic scattering.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


High $p_T \pi^0$ Production From $\alpha \alpha$ and $\alpha p$ Collisions at the {CERN} {ISR}

The CERN-Oxford-Rockefeller collaboration Angelis, A.L.S. ; Basini, G. ; Besch, H.J. ; et al.
Phys.Lett.B 116 (1982) 379-382, 1982.
Inspire Record 178877 DOI 10.17182/hepdata.30879

The invariant cross sections for π 0 meson production in alpha—alpha and alpha—proton collisions at the ISR were meas- ured up to transverse momenta of 7 GeV c and 8 GeV c , respectively. These measurements are compared with π 0 production in pp collisions at the same values of s / nucleon, and the variation of the nuclear A -dependence with p T is determined.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Measurement of the Proton - Anti-proton Elastic and Total Cross-section at a Center-of-mass Energy of 540-{GeV}

The UA4 collaboration Battiston, R. ; Bozzo, M. ; Braccini, P.L. ; et al.
Phys.Lett.B 117 (1982) 126-130, 1982.
Inspire Record 178898 DOI 10.17182/hepdata.30870

First results on the measurement of the elastic and total cross section at the CERN pp̄ Collider are presented. Combining the measurement of elastic scattering at low momentum transfer with the rate of inelastic interactions, a value of the total cross section of 66 mb with a 10% statistical error was obtained.

1 data table
Table 1

STATISTICAL ERROR ONLY.


POSSIBLE OBSERVATION OF DIBARYON RESONANCE IN PROCESSES OF RELATIVISTIC DEUTERON FRAGMENTATION

Ableev, V.G. ; Dimitrov, Kh. ; Filipkowski, A. ; et al.
JINR-E1-82-516, 1982.
Inspire Record 179223 DOI 10.17182/hepdata.39544

None

1 data table
Table 1

No description provided.