scholarly journals Measurement of the e+e− → π+π− process cross section with the SND detector at the VEPP-2000 collider in the energy region 0.525 < $$ \sqrt{s} $$ < 0.883 GeV

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
M. N. Achasov ◽  
◽  
A. A. Baykov ◽  
A. Yu. Barnyakov ◽  
K. I. Beloborodov ◽  
...  
Keyword(s):  
Cross Section ◽  
Systematic Uncertainty ◽  
Energy Region ◽  
The Cross ◽  
Spherical Neutral Detector ◽  
Integrated Luminosity

Abstract The cross section of the process e+e− → π+π− has been measured in the Spherical Neutral Detector (SND) experiment at the VEPP-2000 e+e− collider VEPP-2000 in the energy region 525 <$$ \sqrt{s} $$ s < 883 MeV. The measurement is based on data with an integrated luminosity of about 4.6 pb−1. The systematic uncertainty of the cross section determination is 0.8% at $$ \sqrt{s} $$ s > 0.600 GeV. The ρ meson parameters are obtained as mρ = 775.3 ± 0.5 ± 0.6 MeV, Γρ = 145.6 ± 0.6 ± 0.8 MeV, Bρ→e+e− × Bρ→π+π− = (4.89 ± 0.02 ± 0.04) × 10−5, and the parameters of the e+e− → ω → π+π− process, suppressed by G-parity, as Bω→e+e− × Bω→π+π− = (1.32 ± 0.06 ± 0.02) × 10−6 and and ϕρω = 110.7 ± 1.5 ± 1.0 degrees.

scholarly journals Study of the process e + e– → π+ π– π0 with the CMD-3 detector at the electron-positron collider VEPP-2000

2020 ◽  
Vol 56 (4) ◽  
pp. 449-458
Author(s):  
D. S. Vasileuskaya ◽  
D. N. Grigoriev ◽  
I. G. Dudko ◽  
V. L. Ivanov ◽  
V. F. Kazanin ◽  
...  
Keyword(s):  
Cross Section ◽  
Energy Region ◽  
Electron Positron ◽  
Born Cross Section ◽  
The Cross ◽  
Good Agreement ◽  
Integrated Luminosity

The cross section of the process e+ e– → π+ π– π0 was measured with the CMD-3 detector at the electron-positron collider VEPP-2000 in the energy region from 750 MeV to 800 MeV in c.m.s. This measurement was based on the data collected in 2013 and related to an integrated luminosity of about 7.8 pb–1. The procedure for obtaining the Born cross section and determining the parameters of the ω-meson was worked out. The preliminary ω-meson parameters mω = 782.70 ± 0.02 ± ± 0.11 MeV, Гω = 8.74 ± 0.05 ± 0.22 MeV, σ0(ω → π+ π– π) = 1545 ± 4 ± 39 nb were obtained. The results were compared with previous data and proven to demonstrate a good agreement with them.

Measurement of the cross section of the reaction pn → ppπ− in the energy region of dibaryon resonances (500–1000 MeV)

1982 ◽  
Vol 114 (6) ◽  
pp. 409-413 ◽  
Author(s):  
L.G. Dakhno ◽  
A.V. Kravtsov ◽  
E.A. Lobachev ◽  
M.M. Makarov ◽  
V.I. Medvedev ◽  
...  
Keyword(s):  
Cross Section ◽  
Energy Region ◽  
The Cross

scholarly journals Measurement of the cross-section and charge asymmetry of W bosons produced in proton–proton collisions at $$\sqrt{s}=8~\text {TeV}$$ with the ATLAS detector

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
O. Abdinov ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Charge Asymmetry ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Proton Proton ◽  
Proton Collisions ◽  
The Cross ◽  
Proton Proton Collisions ◽  
Integrated Luminosity

Abstract This paper presents measurements of the $$W^+ \rightarrow \mu ^+\nu $$W+→μ+ν and $$W^- \rightarrow \mu ^-\nu $$W-→μ-ν cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton–proton collisions at a centre-of-mass energy of 8 $$\text {TeV}$$TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of $$20.2~\text{ fb }^{-1}$$20.2fb-1. The precision of the cross-section measurements varies between 0.8 and 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.

scholarly journals Update of the e + e − → π+π− cross section measured by the spherical neutral detector in the energy region 400 < √s < 1000 MeV

2006 ◽  
Vol 103 (3) ◽  
pp. 380-384 ◽  
Author(s):  
M. N. Achasov ◽  
K. I. Beloborodov ◽  
A. V. Berdyugin ◽  
A. G. Bogdanchikov ◽  
A. V. Bozhenok ◽  
...  
Keyword(s):  
Cross Section ◽  
Energy Region ◽  
Spherical Neutral Detector

η PHOTO-PRODUCTION ON THE DEUTERON AT LNS, TOHOKU UNIVERSITY

2010 ◽  
Vol 19 (12) ◽  
pp. 2393-2399 ◽  
Author(s):  
T. Ishikawa
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Systematic Uncertainty ◽  
Cross Sections ◽  
Energy Region ◽  
Solid Angle ◽  
Total Cross Sections ◽  
Nuclear Science ◽  
Electro Magnetic ◽  
Photo Production

The differential and total cross sections were measured for the γp → ηp and γd → ηpn reactions at Eγ ≤ 1150 MeV by using an electro-magnetic (EM) calorimeter SCISSORS II at the Laboratory of Nuclear Science (LNS), Tohoku University. The total cross section on the deuteron shows a bump around Eγ = 1 GeV , while no bump is observed in the same energy region of that on the proton. This bump is attributed to be a nucleon resonance excited from the neutron, and it is a candidate of anti-decuplet penta-quark baryons with hidden strangeness. It was difficult, however, to detect all the γ's coming from η decay since the solid angle of SCISSORS II was only 12.6% in total. Statistics of the detected η produced events is poor and systematic uncertainty of the obtained cross section is not small due to low acceptance. A new EM calorimeter complex called FOREST with a solid angle of about 4π sr has been constructed. The spin and parity of the relevant resonance are expected to be determined by the experiments with FOREST.

Ion-Molekül-Reaktionen und Ladungsaustausch bei Stößen von O– auf O2 / Ion-Molecule Reactions and Charge Transfer in Collisions of O– on O2

1977 ◽  
Vol 32 (1) ◽  
pp. 13-16
Author(s):  
D. Vogt ◽  
W. Dreves ◽  
J. Mischke
Keyword(s):  
Charge Transfer ◽  
Cross Section ◽  
Charge Exchange ◽  
Energy Region ◽  
Lower Energy ◽  
Sharp Maximum ◽  
Ion Molecule Reactions ◽  
Low Energies ◽  
Lower Energy Region ◽  
The Cross

Abstract Investigations of the cross section for the reaction O- + O2 → O2- + O have been made for laboratory kinetic energies 0-100 eV. The reaction shows a sharp maximum in the cross section at low energies (5 eV lab.). By the use of the primary ion 18O- it can be shown that above 20 eV (lab.) there is only charge exchange whereas in the lower energy region ion-molecule-reactions as well as charge exchange occure. The reaction O- + O2 → O+ + … has also been observed above 27 eV (lab.).

The 98° differential cross sections for the reactions 13C(γ,n0)12C and 13C(γ,n1)12C

1977 ◽  
Vol 55 (19) ◽  
pp. 1704-1715 ◽  
Author(s):  
J. G. Woodworth ◽  
K. G. McNeill ◽  
J. W. Jury ◽  
P. D. Georgopulos ◽  
R. G. Johnson
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Energy Region ◽  
Level Structure ◽  
Similar Reaction ◽  
Differential Cross Sections ◽  
Isospin Splitting ◽  
The Cross ◽  
Theoretical Results

The differential cross sections at 98° for the reactions 13C(γ,n0)12C and 13C(γ,n1)12C were measured over the range of 6.0 to 37.0 MeV and 10.5 to 35.5 MeV, respectively. The cross sections are compared with previous results on the same nucleus or results from the similar reaction 12C(p,γ0)13N. In the region of the so-called pygmy resonance (about 13.5 MeV) there are many sharp resonances which correspond very well with the level structure of 13C as deduced from several other studies using various reactions. For the full energy region studied, further evidence for the isospin splitting of the 13C photoneutron cross section is obtained. In comparison of the cross sections with recent theoretical results, general agreement is obtained. However, several details of this comparison are in disagreement; the implications of this disagreement are discussed.

Analysis of the cross section for 232Th photofission in the subbarrier energy region

2009 ◽  
Vol 72 (6) ◽  
pp. 917-927 ◽  
Author(s):  
A. I. Blokhin ◽  
A. S. Soldatov
Keyword(s):  
Cross Section ◽  
Energy Region ◽  
The Cross

scholarly journals Study of the process e+e-→ π+π-π0η at the SND detector

2019 ◽  
Vol 212 ◽  
pp. 03009
Author(s):  
Alexander Botov
Keyword(s):  
Cross Section ◽  
Energy Region ◽  
Center Of Mass ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
Intermediate States ◽  
Reaction Proceeds ◽  
The Cross ◽  
Π State

The reaction e+e-→ π+π-π0η has been studied in the center-of-mass energy region below 2 GeV in the experiment with the SND detector at the VEPP-2000 e+e- collider. The reaction proceeds via the four intermediate states: ωη, $ \phi \eta $, a0(980)ρ, and a structureless π+π-π0η state, which may be, for example, ρ(1450)π state with ρ(1450) → ρ(770)η. The total e+e-→ π+π-π0η cross section and the cross section for its components, ωη, $ \phi \eta $, and a sum of a0(980)ρ and the structureless state, have been measured separately. Our results are in agreement with previous measurements and have comparable or better accuracies.

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