Date

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 match query

No description provided.


Search for Direct Single Photon Production at Large p(T) in Proton Proton Collisions at s**(1/2) = 62.4-GeV

The CERN-Columbia-Oxford-Rockefeller & CCOR collaborations Angelis, A.L.S. ; Besch, H.J. ; Blumenfeld, Barry J. ; et al.
Phys.Lett.B 94 (1980) 106-112, 1980.
Inspire Record 153483 DOI 10.17182/hepdata.27178

As part of a study of large p T phenomena in photon-proton collisions at the CERN ISR, a search for direct single photon production has been performed. A statistical division of the data sample into the fraction consistent with single photon and the fraction due to multiphoton decays of neutral hadrons is accomplished by measuring the average conversion probability for the sample in a one radiation length thick converter. The fraction of the sample attributable to direct single photon production is 〈 γ /all〉 = 0.074 ± 0.012 for 6 GeV/ c < p T 10 GeV/ c , and 〈 γ /all〉 = 0.26 ± 0.04 for p T > 10 GeV/ c , with an additional systematic uncertainty of ±0.05 for both values.

1 data table match query

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 match query

No description provided.

No description provided.


A Determination of the Pion Structure Function from Muon Pair Production

Newman, C.B. ; Anderson, K.J. ; Coleman, R.N. ; et al.
Phys.Rev.Lett. 42 (1979) 951, 1979.
Inspire Record 140037 DOI 10.17182/hepdata.20767

Data on muon-pair production by pions are used to determine the momentum distribution for valence quarks in the pion. The shape of a nucleon structure function is also obtained and is compared with a calculation based on existing data.

1 data table match query

No description provided.


Jets in High Transverse Energy Events at the {CERN} Intersecting Storage Rings

The CMOR collaboration Angelis, A.L.S. ; Basini, G. ; Besch, H.J. ; et al.
Nucl.Phys.B 244 (1984) 1-22, 1984.
Inspire Record 202452 DOI 10.17182/hepdata.33870

Most events with high neutral transverse energy, E T 0 , produced in pp colisions at √ s = 62.3 GeV, are jet-like. The evidence for this is presented, based on data collected using an electromagnetic calorimeter covering 90% of 2π in azimuth. The spectrum d N /d E T 0 has been measured over the E T 0 range from 10 to 35 GeV. Properties of the observed jets are discussed.

1 data table match query

No description provided.


Large Transverse Momentum $\pi^0$ Production in $\alpha \alpha d d$ and $p p$ Collisions at the {CERN} {ISR}

The BCMOR collaboration Angelis, A.L.S. ; Basini, G. ; Besch, H.J. ; et al.
Phys.Lett.B 185 (1987) 213-217, 1987.
Inspire Record 222768 DOI 10.17182/hepdata.30194

None

1 data table match query

No description provided.


A Study of massive electron pairs and associated particles produced at the CERN ISR

The CERN-Michigan State-Oxford-Rockefeller collaboration Angelis, A.L.S. ; Basini, G. ; Besch, H.J. ; et al.
Nucl.Phys.B 348 (1991) 1-22, 1991.
Inspire Record 298427 DOI 10.17182/hepdata.33054

A sample of 105 e + e − events with an invariant mass greater than 11 GeV/ c 2 produced in pp collisions at a center-of-mass energy of 62.3 GeV is discussed. Cross sections are presented as a function of mass and transverse momentum. The multiplicity, transverse momentum, and azimuthal dependence of associated particles are also studied.

3 data tables match query

No description provided.

No description provided.

No description provided.


Production of $\pi^0 \pi^0$ and $\pi^0 \eta$ in Photon - Photon Collisions

Edwards, C. ; Partridge, Richard ; Peck, C. ; et al.
Phys.Lett.B 110 (1982) 82-86, 1982.
Inspire Record 168793 DOI 10.17182/hepdata.30959

We investigate the four-photon final state produced in γγ colissions. In the π 0 π 0 channel we observe f(1270) production with predominantly helicity 2 and measure a partial width Γ γγ 2.9 +0.6 −0.4 ± keV (independent of assumptions on the helicity). We observe A 2 (1310) production in the π 0 η channel and find a partial width Γ γγ = 0.77 ± 0.18 ± 0.27 KeV (assuming helicity 2). We give an upper limit for f ≈ ηη .

3 data tables match query

Data read from graph. Systematic error on M is of order of 2% or less.

Data read from graph.

No description provided.


Hadron Production in $e^+ e^-$ Annihilation From $\sqrt{s}=5$-{GeV} to 7.4-{GeV}

Edwards, C. ; Partridge, Richard ; Peck, C. ; et al.
SLAC-PUB-5160, 1990.
Inspire Record 294419 DOI 10.17182/hepdata.18758

None

4 data tables match query

Data from Run 1. There is an additional overall systematic uncertainty of 5.2 pct.

Data from Run 2. There is an additional overall systematic uncertainty of 5.2 pct.

Average R value.

More…

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 match query

No description provided.

No description provided.