MEASUREMENTS OF ABSOLUTE PAIR PRODUCTION CROSS SECTIONS AT LOW ENERGIES

1958 ◽  
Vol 36 (9) ◽  
pp. 1154-1160 ◽  
Author(s):  
S. Standil ◽  
V. Shkolnik
Keyword(s):  
Pair Production ◽  
Cross Section ◽  
Gamma Rays ◽  
Cross Sections ◽  
Production Cross ◽  
Relative Method ◽  
Low Energies

Using an improved analysis in conjunction with a relative method for the measurement of absolute pair production cross sections, the pair production cross sections per atom of lead have been measured for the gamma rays emitted by Co60 and Sb124. The Z-dependence of this cross section was measured for the Co60 radiation using targets of Al, Fe, Cu, Mo, Ag, Sn, and Pb. The results obtained are generally in agreement with other experimental determinations and are, along with those of other investigators, represented graphically.

scholarly journals PRELIMINARY MEASUREMENTS OF THE QUARK-ANTIQUARK PRODUCTION CROSS-SECTION IN E+E- ANNIHILATIONS UP TO LEP2 HIGHEST ENERGIES

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 342-344
Author(s):  
GIUSEPPE DELLA RICCA
Keyword(s):  
Standard Model ◽  
Pair Production ◽  
Cross Section ◽  
Cross Sections ◽  
Production Cross Section ◽  
Production Cross ◽  
Delphi Detector ◽  
The Standard Model ◽  
Model Predictions ◽  
The Cross

Data collected with the DELPHI detector at [Formula: see text] up to LEP2 highest energies (i.e. exceeding 205 GeV) have been used to extract preliminary values of the cross-sections for quark-antiquark pair-production in e + e - annihilations. The values found were used to test the Standard Model predictions and to seek for physics beyond it.

THE ENERGIES AND RELATIVE PAIR PRODUCTION CROSS SECTIONS FOR Zn65 AND Na22 GAMMA RAYS

1959 ◽  
Vol 37 (9) ◽  
pp. 1055-1058 ◽  
Author(s):  
P. P. Singh ◽  
H. W. Dosso ◽  
G. M. Griffiths
Keyword(s):  
Pair Production ◽  
Gamma Rays ◽  
Cross Sections ◽  
Production Cross ◽  
Relative Pair

scholarly journals Top cross-sections and single top

2014 ◽  
Vol 31 ◽  
pp. 1460277 ◽  
Author(s):  
Reinhard Schwienhorst ◽  
Keyword(s):  
Pair Production ◽  
Cross Section ◽  
Cross Sections ◽  
Top Quark ◽  
Production Cross ◽  
Decay Modes ◽  
Single Top ◽  
Top Quark Production ◽  
Quark Production

This paper summarizes top quark cross-section measurements at the Tevatron and the LHC. Top quark pair production cross-sections have been measured in all decay modes by the ATLAS and CMS collaborations at the LHC and by the CDF and D0 collaborations at the Tevatron. Single top quark production has been observed at both the Tevatron and the LHC. The t-channel and associated Wt production modes have been observed at the LHC and evidence for s-channel production has been reported by the Tevatron collaborations.

ABSOLUTE PAIR PRODUCTION CROSS SECTION OF LEAD AT 2.76 MEV.

1956 ◽  
Vol 34 (11) ◽  
pp. 1126-1133 ◽  
Author(s):  
S. Standil ◽  
R. D. Moore
Keyword(s):  
Pair Production ◽  
Cross Section ◽  
Gamma Rays ◽  
Production Cross Section ◽  
Detection Efficiency ◽  
Production Cross ◽  
Separate Experiment ◽  
Annihilation Radiation ◽  
Coincidence Counting ◽  
Pair Production Cross Section

A value has been obtained for the absolute pair production cross section of lead for the 2.76 Mev. gamma rays of Na24. A collimated beam of these gamma rays was made to fall on a specially constructed target and the positrons produced in the target were detected by counting two-quanta annihilation events by means of two scintillation spectrometers in coincidence. The strength of the Na24 source was measured by a coincidence counting technique and the counter detection efficiency for annihilation radiation was measured with a calibrated Na22 source. The effect of absorption of the 0.511 Mev. annihilation radiation in the target was measured in a separate experiment. The value obtained for the cross section was 2.38 ± 0.62 barns.

scholarly journals INDIRECT SEARCHES FOR LEPTOQUARKS AT PRESENT AND FUTURE COLLIDERS

1988 ◽  
Vol 03 (04) ◽  
pp. 443-450 ◽  
Author(s):  
H. DREINER ◽  
J. ELLIS ◽  
D.V. NANOPOULOS ◽  
N.D. TRACAS ◽  
N.D. VLACHOS
Keyword(s):  
Total Cross Section ◽  
Pair Production ◽  
Cross Section ◽  
Cross Sections ◽  
Indirect Effects ◽  
Production Cross ◽  
Lepton Pair ◽  
Hadron Colliders ◽  
Scalar Particles ◽  
Lepton Pair Production

We explore the sensitivities of e+e− colliders (LEP, CLIC) and hadron-hadron colliders (CERN [Formula: see text], FNAL [Formula: see text], LHC pp and SSC pp) to the indirect effects of virtual scalar particles with superstring-inspired leptoquark and diquark couplings. We find that e+e− colliders have better sensitivities via total cross section measurements of [Formula: see text] than via asymmetry measurements, and that LEP 2 is much more sensitive than LEP 1. Hadron-hadron colliders are sensitive via lepton-pair production cross sections ( [Formula: see text]μ+μ−, τ+τ−).

scholarly journals Collinear expansion for color singlet cross sections

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Markus A. Ebert ◽  
Bernhard Mistlberger ◽  
Gherardo Vita
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Production Cross ◽  
Gluon Fusion ◽  
Building Blocks ◽  
Color Singlet ◽  
Final State ◽  
Beam Function ◽  
Kinematic Limit ◽  
State Radiation

Abstract We demonstrate how to efficiently expand cross sections for color-singlet production at hadron colliders around the kinematic limit of all final state radiation being collinear to one of the incoming hadrons. This expansion is systematically improvable and applicable to a large class of physical observables. We demonstrate the viability of this technique by obtaining the first two terms in the collinear expansion of the rapidity distribution of the gluon fusion Higgs boson production cross section at next-to-next-to leading order (NNLO) in QCD perturbation theory. Furthermore, we illustrate how this technique is used to extract universal building blocks of scattering cross section like the N-jettiness and transverse momentum beam function at NNLO.

scholarly journals Charged current Drell-Yan production at N3LO

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Claude Duhr ◽  
Falko Dulat ◽  
Bernhard Mistlberger
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Production Cross Section ◽  
Production Cross ◽  
Hadron Collider ◽  
Charge Asymmetry ◽  
Charged Current ◽  
Leading Order ◽  
Neutrino Pair ◽  
The Impact

Abstract We present the production cross section for a lepton-neutrino pair at the Large Hadron Collider computed at next-to-next-to-next-to-leading order (N3LO) in QCD perturbation theory. We compute the partonic coefficient functions of a virtual W± boson at this order. We then use these analytic functions to study the progression of the perturbative series in different observables. In particular, we investigate the impact of the newly obtained corrections on the inclusive production cross section of W± bosons, as well as on the ratios of the production cross sections for W+, W− and/or a virtual photon. Finally, we present N3LO predictions for the charge asymmetry at the LHC.

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