Hansen, K.H.
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Search for Direct $\gamma$ Production at Low Transverse Momentum in 63-{GeV} $p p$ Collisions

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Rev.D 36 (1987) 2615, 1987.
Inspire Record 246577 DOI 10.17182/hepdata.23325

We have searched for direct photons of low PT (≤1.0 GeV/c) at θc.m.=90° in pp collisions at √s =63 GeV. We used two independent methods: direct detection in NaI crystals and conversion to e+e− pairs. No signal is observed; the photon spectrum is well described by the decay of hadrons. The result is consistent with a direct low-PT photon signal reported at √s =12 GeV, but excludes a rapid growth of soft-photon production with √s .

1 data table match query
Table 1

No description provided.


Direct Photon Plus Away - Side Jet Production in $p p$ Collisions at $s^1$/2 = 63-{GeV} and a Determination of the Gluon Distribution

The Axial Field Spectrometer collaboration Åkesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Z.Phys.C 34 (1987) 293, 1987.
Inspire Record 235690 DOI 10.17182/hepdata.15800

We have determined the double inclusive cross-section for opposite-side high-pT photons and away-side jets withθγ≈θjet≈90° produced inpp collisions at the CERN Intersecting Storage Rings at\(\sqrt s= 63\) GeV. Under the assumption that these events arise predominantly from the QCD gluon Compton process we have calculated the gluon structure function in the range 0.15≦x≦0.30 at an average square of the four-momentum transfer of 40 GeV2/c2. The data favour a soft gluon distribution in the proton.

2 data tables match query
Table 1

No description provided.

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A Study of the Production of Two Direct Photons in $p p$ Collisions at the {CERN} {ISR}

The Axial Field Spectrometer collaboration Åkesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Z.Phys.C 32 (1986) 491-497, 1986.
Inspire Record 228954 DOI 10.17182/hepdata.15834

We have studied the processpp→γγ+X at\(\sqrt s= 63 GeV\) GeV in the central rapidity region. We report a positive signal at 96% C.L., a ratio γγ/e+e−=4.0±3.0 when the transverse momentum of each photon is above 2 GeV/c, and a cross-sectiondσ/dydMγγ=(5.5±2.7)×10−34 cm2/GeV when |y|<0.5,4<Mγγ<6 GeV.

1 data table match query
Table 1

No description provided.


Production of $\pi^0$ and Eta0 at 11-degrees in $p p$ Collisions at $\sqrt{s}=63$-{GeV}

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Z.Phys.C 18 (1983) 5, 1983.
Inspire Record 188928 DOI 10.17182/hepdata.16326

The inclusive π0 production cross-section and the η/π0 ratio have been measured inpp collisions at\(\sqrt s= 63 GeV\) at the CERN Intersecting Storage Rings in the rapidity range 2.00<y<2.75. The π0 cross-section exhibits a strongy-dependence and falls more steeply as a function ofpT, compared with the cross-section measured aty∼0. We find a value of 0.46±0.07 for the η/π0 ratio with no significantpT dependence over the range 2.0<pT<4.0 GeV/c.

2 data tables match query
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No description provided.

Table 2

No description provided.


Charged kaon and pion production at midrapidity in proton nucleus and sulphur nucleus collisions.

The NA44 collaboration Boggild, H. ; Boissevain, J. ; Dodd, J. ; et al.
Phys.Rev.C 59 (1999) 328-335, 1999.
Inspire Record 474831 DOI 10.17182/hepdata.25575

The NA44 collaboration has measured charged kaon and pion distributions at midrapidity in sulphur and proton collisions with nuclear targets at 200 and 450 GeV/c per nucleon, respectively. The inverse slopes of kaons are larger than those of pions. The difference in the inverse slopes of pions, kaons and protons, all measured in our spectrometer, increases with system size and is consistent with the buildup of collective flow for larger systems. The target dependence of both the yields and inverse slopes is stronger for the sulphur beam suggesting the increased importance of secondary rescattering for SA reactions. The rapidity density, dN/dy, of both K+ and K- increases more rapidly with system size than for pi+ in a similar rapidity region. This trend continues with increasing centrality, and according to RQMD, it is caused by secondary reactions between mesons and baryons. The K-/K+ ratio falls with increasing system size but more slowly than the pbar/p ratio. The pi-/pi+ ratio is close to unity for all systems. From pBe to SPb the K+/p ratio decreases while K-/pbar increases and ({K+*K-}/{p*pbar})**1/2 stays constant. These data suggest that as larger nuclei collide, the resulting system has a larger transverse expansion, baryon density and an increasing fraction of strange quarks.

8 data tables match query
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No description provided.

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A Comparison of Hadron Production in $p \bar{p}$ and $p p$ Collisions in the Central Region at $\sqrt{s}=53$-{GeV}

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Nucl.Phys.B 228 (1983) 409-423, 1983.
Inspire Record 190653 DOI 10.17182/hepdata.37131

We have studied the inclusive production of the hadrons π ± , K ± , p, p , Λ, Λ , ρ and ⋉ in the central region at the ISR s = 53 GeV , in both pp and p p collisions. Differences are observed only for K ± , p, and p production. We then study also correlations between low- p T pp and p p pairs in the two types of collisions, separating the contribution from baryon pair production and from the incident particles (stopping protons). We observe a positive correlation between two stopping protons; between the production of two pairs, and between a stopping proton and a pair production, there are negative correlations.

1 data table match query
Table 1

No description provided.


Production of high transverse momentum particles in p p collisions in the central region at the CERN ISR

The British-Scandinavian ISR collaboration Alper, B. ; Boggild, H. ; Jarlskog, G. ; et al.
Phys.Lett.B 44 (1973) 521-526, 1973.
Inspire Record 85256 DOI 10.17182/hepdata.28095

The inclusive production al all charged particles of transverse momentum p T between 1.5 and 4.4 GeV/ c at centre of mass angles 90° and 59.4° from p-p-collisions with √ s = 44 and 53 GeV has been measured. No strong energy dependence is observed for these transverse momenta.

6 data tables match query
Table 1

Errors are statistical only.

Table 2

Errors are statistical only.

Table 3

Errors are statistical only.

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Inclusive $\rho^0$ Production in $p p$ Collisions at the {CERN} {ISR}

The British-French-Scandinavian collaboration Albrow, M.G. ; Almehed, S. ; Booth, P.S.L. ; et al.
Nucl.Phys.B 155 (1979) 39-51, 1979.
Inspire Record 133360 DOI 10.17182/hepdata.34664

The inclusive production of ϱ 0 mesons in pp collisions has been measured at five c.m. energies from √ s = 23.6 to 63.0 GeV. The cross sections and the production spectra as a function of transverse momentum and rapidity are discussed.

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


The Dominance of Jets at Large Transverse Energy in a Full Azimuth Hadron Calorimeter at {ISR} Energies

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Lett.B 128 (1983) 354-360, 1983.
Inspire Record 190652 DOI 10.17182/hepdata.30701

Events with a large transverse energy in a calorimeter with full azimuthal coverage and | y | < 0.9 have been investigated in pp collisions at √ s = 30, 45, and 63 GeV. A striking change in the event structure, corresponding to a clear emergence of high- p T jets, is observed at √ s = 63 and 45 GeV in the region between 25 and 35 GeV in transverse energy. At √ s = 30 GeV, the data extend to E T ∼ 20 GeV, but no such change in the event structure is observed.

3 data tables match query
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No description provided.

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Bose-einstein Correlations in $\alpha \alpha$, $p p$ and $p \bar{p}$ Interactions

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Lett.B 129 (1983) 269-272, 1983.
Inspire Record 190654 DOI 10.17182/hepdata.30661

Bose-Einstein correlations between pions produced in the central region of rapidity in αα, pp and p p interactions have been studied at the ISR. The parameters r and τ c -often interpreted as the radius and depth of the π-emitting region - are found to be independent of incident particle type but to depend on the mean charged multiplicity. In high multiplicity events, the pions appear to originate from a larger space-time region.

12 data tables match query
Table 1

FOR DEFINITION OF R++ SEE PAPER.

Table 2

FOR DEFINITION OF R++ SEE PAPER.

Table 3

FOR DEFINITIONS OF R++ AND TAU*C SEE PAPER.

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