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.

scholarly journals MEASUREMENT OF THE $e^+e^- \to p \bar{p}$ CROSS SECTION WITH THE CMD-3 DETECTOR AT VEPP-2000

2014 ◽  
Vol 35 ◽  
pp. 1460457 ◽  
Author(s):  
R. R. AKHMETSHIN ◽  
A. V. ANISENKOV ◽  
V. M. AULCHENKO ◽  
V. S. BANZAROV ◽  
L. M. BARKOV ◽  
...  
Keyword(s):  
Energy Range ◽  
Cross Section ◽  
Drift Chamber ◽  
Event Selection ◽  
Preliminary Results ◽  
Electron Positron ◽  
Clean Sample ◽  
Good Agreement ◽  
Integrated Luminosity

We report preliminary results on the measurement of the [Formula: see text] cross section with the CMD-3 detector at the VEPP-2000 electron-positron collider based on 4.5 pb-1 of integrated luminosity collected in the c.m. energy range 1.92 - 2.0 GeV. Event selection using information from the Drift Chamber and Calorimeters provides a clean sample of [Formula: see text] events. The obtained results are in good agreement with the previous measurements.

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.

A measurement of the cross section for production of He + (2 S ) ions by electron impact excitation of ground state helium ions

1966 ◽  
Vol 290 (1420) ◽  
pp. 74-93 ◽  
Keyword(s):  
Plane Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Absolute Magnitude ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Close Coupling ◽  
Born Cross Section ◽  
The Absolute ◽  
The Cross

A crossed beams method has been used to measure the cross section for the production of He + (2 S ) by electrons incident upon He + (1 S ) in the energy range from threshold to 750 eV. The cross section was measured in arbitrary units with an accuracy of ± 5 % and at the higher energies its energy dependence is in close agreement with that calculated by means of the plane-wave Born approximation. Consequently the cross section has been normalized to the plane-wave Born cross section at energies between 435 and 750 eV to obtain the absolute magnitude. An independent estimate of the absolute magnitude was made to with in ± 30 % using only the experimental parameters, and the absolute cross sections given by the two methods agree within the experimental uncertainties. The normalized cross section is compared with cross sections given by the close-coupling approximation and various Coulomb-Born approximations. At the lower energies the normalized cross section is considerably smaller than any of the theoretical values, but the measurements are consistent with the existence of a finite cross section at threshold if the energy spread of the electron beam is taken in to account.

scholarly journals Double Higgs boson production and Higgs self-coupling extraction at CLIC

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Philipp Roloff ◽  
Ulrike Schnoor ◽  
Rosa Simoniello ◽  
Boruo Xu
Keyword(s):  
Higgs Boson ◽  
Cross Section ◽  
W Boson ◽  
Linear Collider ◽  
Invariant Mass Distribution ◽  
Gauge Coupling ◽  
High Energy ◽  
Electron Positron ◽  
The Cross ◽  
Detector Simulation

AbstractThe Compact Linear Collider (CLIC) is a future electron–positron collider that will allow measurements of the trilinear Higgs self-coupling in double Higgs boson events produced at its high-energy stages with collision energies from $$\sqrt{s}$$ s  = 1.4 to 3 TeV. The sensitivity to the Higgs self-coupling is driven by the measurements of the cross section and the invariant mass distribution of the Higgs-boson pair in the W-boson fusion process, $$\text {e}^{+}\text {e}^{-}\rightarrow {\text {H}\text {H}\nu \bar{\nu }}$$ e + e - → HH ν ν ¯ . It is enhanced by including the cross-section measurement of ZHH production at 1.4 TeV. The expected sensitivity of CLIC for Higgs pair production through W-boson fusion is studied for the decay channels $$\mathrm{b}\bar{\mathrm{b}}\mathrm{b}\bar{\mathrm{b}}$$ b b ¯ b b ¯   and $$\mathrm{b}\bar{\mathrm{b}}\mathrm{W}\mathrm{W}^{*}$$ b b ¯ W W ∗   using full detector simulation including all relevant backgrounds at $$\sqrt{s}$$ s = 1.4 TeV with an integrated luminosity of $$\mathcal {L}$$ L  = 2.5 ab$$^{-1}$$ - 1 and at $$\sqrt{s}$$ s = 3 TeV with $$\mathcal {L}$$ L  = 5 ab$$^{-1}$$ - 1 . Combining $$\text {e}^{+}\text {e}^{-}\rightarrow {\text {H}\text {H}\nu \bar{\nu }}$$ e + e - → HH ν ν ¯ and ZHH  cross-section measurements at 1.4 TeV with differential measurements in $$\text {e}^{+}\text {e}^{-}\rightarrow {\text {H}\text {H}\nu \bar{\nu }}$$ e + e - → HH ν ν ¯ events at 3 TeV, CLIC will be able to measure the trilinear Higgs self-coupling with a relative uncertainty of $$-8\%$$ - 8 % and $$ +11\%$$ + 11 % at 68% C.L., assuming the Standard Model. In addition, prospects for simultaneous constraints on the trilinear Higgs self-coupling and the Higgs-gauge coupling HHWW are derived based on the $${\text {H}\text {H}\nu \bar{\nu }}$$ HH ν ν ¯ measurement.

The inner shell ionization of atoms by electron impact

1940 ◽  
Vol 36 (1) ◽  
pp. 43-52 ◽  
Author(s):  
E. H. S. Burhop ◽  
H. S. W. Massey
Keyword(s):  
Experimental Data ◽  
Electron Impact ◽  
Cross Section ◽  
Nickel Silver ◽  
Inner Shell Ionization ◽  
Good For ◽  
The Cross ◽  
Shell Ionization ◽  
Good Agreement

Calculations have been made of the cross-section for ionization of the inner shells of atoms by electron impact in the cases of the K-shells of nickel, silver, mercury and of the three L-shells of silver and mercury.The agreement with experiment is reasonably good for the K-shell ionization, but only fair in the case of the rather meagre experimental data available for the L-shell. The values obtained for the relative ionization in the K- and L-shells are in good agreement with those to be expected from experiment.

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

Electron loss cross sections from rare gas atoms to Ar+

1982 ◽  
Vol 60 (7) ◽  
pp. 977-980
Author(s):  
B. Hird ◽  
S. P. Ali
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Energy Region ◽  
Rare Gas ◽  
Electron Loss ◽  
Rare Gases ◽  
Thin Target ◽  
Rare Gas Atoms ◽  
Good Agreement

Measurements of the σ10 cross section for a beam of Ar+ ions of energies between 30 and 120 keV passing through a thin target of the rare gases show good agreement with the few previous measurements in this energy region.

Charge transfer from rare gas atoms to Kr+

1982 ◽  
Vol 60 (7) ◽  
pp. 981-987 ◽  
Author(s):  
B. Hird ◽  
S. P. Ali
Keyword(s):  
Charge Transfer ◽  
Energy Dependence ◽  
Cross Section ◽  
Rare Gas ◽  
Zener Model ◽  
Energy Data ◽  
Model Predictions ◽  
Rare Gas Atoms ◽  
The Cross ◽  
Good Agreement

The cross section for electron capture by Kr+ ions from rare gas atoms between 30 and 120 keV is found to be in good agreement with previous measurements where these exist, except for neon. The Rapp–Francis model gives an acceptable fit to the energy dependence of these and higher energy data but is too large by a factor of about five. In contrast the Landau–Zener model predictions are too large for helium and neon and too small for the heavier targets unless metastable states of krypton with large polarizabilities dominate the cross section.

A new empirical formula for cross-sections of (n,nα) reactions

2020 ◽  
Vol 29 (08) ◽  
pp. 2050062
Author(s):  
Mustafa Yiğit
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Empirical Formula ◽  
Nuclear Reactions ◽  
Measured Cross Section ◽  
Future Studies ◽  
Present Formalism ◽  
The Cross ◽  
Neutron Cross Sections ◽  
Good Agreement

Studies on the cross-sections of (n,n[Formula: see text]) reactions which are energetically possible, about 14 MeV neutrons are quite scarce. In this paper, the cross-sections of (n,n[Formula: see text] nuclear reactions at [Formula: see text]14–15 MeV are analyzed by using a new empirical formula based on the statistical theory. We show that neutron cross-sections are closely related to the [Formula: see text]-value of nuclear reaction, in particular for (n,n[Formula: see text]) channels. Results obtained with this empirical formula show good agreement with the available measured cross-section values. We hope that the estimations on the cross-sections using the present formalism may be helpful in future studies in this field.

scholarly journals Cross Section Ionization By Electron Impact Of Helium Like Ions

2021 ◽  
Author(s):  
Manel Hariz Belgacem ◽  
Elhabib Guedda ◽  
Haikel Jelassi
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
The Cross ◽  
State 1 ◽  
Unstable States ◽  
Good Agreement

<sub></sub> In this paper we present our calculation of the cross section ionization by electron impact of C V, N VI and O VII. Using the Flexible Atomic Code (FAC), we obtain the cross sections for the ionization of these ions from the ground state 1<sup>1</sup>S, and from the unstable states 2<sup>1</sup>S and 2<sup>3</sup>S. Our results are in good agreement with those based on the Coulomb Born (CB) approximation and the available measurements.

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