scholarly journals Astrophysical S-factor for the 2H(ρ,γ)3He reaction at big-bang nucleosynthesis energies

2020 ◽  
Vol 227 ◽  
pp. 02015
Author(s):  
Isabela Tišma ◽  
Matej Lipoglavšek ◽  
Miha Mihoviloviĉ ◽  
Sabina Markelj ◽  
Matjaž Vencelj ◽  
...  
Keyword(s):  
Energy Range ◽  
Ab Initio ◽  
Center Of Mass ◽  
Big Bang ◽  
Angular Distributions ◽  
Mass Energy ◽  
Big Bang Nucleosynthesis ◽  
Center Of Mass Energy ◽  
S Factor ◽  
Γ Ray

We report on our latest experimental study of the 2H(ρ,γ)3He reaction in the energy range of interest for big-bang nucleosynthesis. The differential cross section at 135° and γ)-ray angular distributions were measured and compared with the results deduced from the latest ab-initio calculation. The astrophysical S-factor for the 2H(ρ,γ)3He reaction was obtained in the center-of-mass energy range E = 97-210 keV, and it is found to be in reasonable agreement with that predicted by the ab-initio calculation.

scholarly journals Non-strange dibaryons studied in coherent double neutral-meson photoproduction on the deuteron

2020 ◽  
Vol 241 ◽  
pp. 01007
Author(s):  
Takatsugu Ishikawa ◽  
Hisako Fujimura ◽  
Hiroshi Fukasawa ◽  
Ryo Hashimoto ◽  
Qinghua He ◽  
...  
Keyword(s):  
Invariant Mass Distribution ◽  
Center Of Mass ◽  
Resonance State ◽  
Angular Distributions ◽  
Neutral Meson ◽  
Mass Energy ◽  
Meson Photoproduction ◽  
Neutral Pions ◽  
Center Of Mass Energy ◽  
Interesting Object

The B = 2 bound/resonance state (dibaryon) is an interesting object, which can be a molecule consisting of two baryons or a spatially compact hexaquark hadron object. The yd ^ n°n°d reaction has been experimentally investigated at incident energies ranging from 0.58 to 1.15 GeV to study non-strange dibaryons. The angular distributions of deuteron emission in the yd center-of-mass energy cannot be reproduced by quasi-free production of two neutral pions followed by deuteron coalescence. Additionally a 2.14-GeV peak is observed in the n°d invariant mass distribution. These suggest a sequential process such as yd ^ RIS ^ n°RIV ^ n°n°d with an isoscalar dibaryon RIS and an isovector dibaryon RIV. Since the mass of the observed isoscalar dibaryons are close to the sum of the nucleon (N) and nucleon resonance (N*) masses, an S-wave NN* molecule may play a role as a doorway to a dibaryon.

scholarly journals Study of the process $$e^+e^- \rightarrow \eta \pi ^0\gamma $$ in the energy range $$\sqrt{s} = {1.05-2.00}$$ GeV with the SND detector

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
M. N. Achasov ◽  
A. Yu. Barnyakov ◽  
A. A. Baykov ◽  
K. I. Beloborodov ◽  
A. V. Berdyugin ◽  
...  
Keyword(s):  
Energy Range ◽  
Cross Section ◽  
Center Of Mass ◽  
Wide Energy Range ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
Wide Energy ◽  
Radiation Processes ◽  
Using Data ◽  
First Time

AbstractThe process $$e^+e^-\rightarrow \eta \pi ^0\gamma $$ e + e - → η π 0 γ is studied in the center-of-mass energy range 1.05–2.00 GeV using data with an integrated luminosity of 94.5 $$\hbox {pb}^{-1}$$ pb - 1 collected by the SND detector at the VEPP-2000 $$e^{+}e^{-}$$ e + e - collider. The $$e^+e^-\rightarrow \eta \pi ^0\gamma $$ e + e - → η π 0 γ cross section is measured for the first time. It is shown that the dominant mechanism of this reaction is the transition through the $$\omega \eta $$ ω η intermediate state. The measured cross section of the subprocess $$e^+e^-\rightarrow \omega \eta \rightarrow \eta \pi ^0\gamma $$ e + e - → ω η → η π 0 γ is consistent with previous measurements in the $$e^+e^-\rightarrow \pi ^+\pi ^-\pi ^0\eta $$ e + e - → π + π - π 0 η mode. It is found, with a significance of $$5.6\sigma $$ 5.6 σ , that the process $$e^+e^-\rightarrow \eta \pi ^0\gamma $$ e + e - → η π 0 γ is not completely described by hadronic vector-pseudoscalar intermediate states. The cross section of this missing contribution, which can originate from radiation processes, e. g. $$e^+e^-\rightarrow a_{0}(1450)\gamma $$ e + e - → a 0 ( 1450 ) γ , is measured. It is found to be 15–20 pb in the wide energy range from 1.3 to 1.9 GeV.

scholarly journals Study of the processe+e−→ηγin the center-of-mass energy range 1.07–2.00 GeV

2014 ◽  
Vol 90 (3) ◽  
Author(s):  
M. N. Achasov ◽  
V. M. Aulchenko ◽  
A. Yu. Barnyakov ◽  
K. I. Beloborodov ◽  
A. V. Berdyugin ◽  
...  
Keyword(s):  
Energy Range ◽  
Center Of Mass ◽  
Mass Energy ◽  
Center Of Mass Energy

scholarly journals An amplitude analysis of the process e+e-→ 4π in the center-of-mass energy range 900–2000 MeV with the CMD3 detector at the VEPP-2000 e+e- collider

2019 ◽  
Vol 212 ◽  
pp. 03008
Author(s):  
E. A. Kozyrev ◽  
R. R. Akhmetshin ◽  
A. N. Amirkhanov ◽  
A. V. Anisenkov ◽  
V. M. Aulchenko ◽  
...  
Keyword(s):  
Energy Range ◽  
Center Of Mass ◽  
Large Data ◽  
Mass Energy ◽  
Amplitude Analysis ◽  
Center Of Mass Energy

A large data sample of e+e-→ 4π collected by the CMD-3 experiment at the VEPP-2000 e+ e− collider allowed for an amplitude analysis of the process e+e−→ 4π in the center-of-mass energy range 900–2000 MeV. Various intermediate components were distinguished and dominance of the ωπ0 and a1π amplitudes has been proved.

scholarly journals Study of the process e+e−→K+K− in the center-of-mass energy range 1010–1060 MeV with the CMD-3 detector

2018 ◽  
Vol 779 ◽  
pp. 64-71 ◽  
Author(s):  
E.A. Kozyrev ◽  
E.P. Solodov ◽  
R.R. Akhmetshin ◽  
A.N. Amirkhanov ◽  
A.V. Anisenkov ◽  
...  
Keyword(s):  
Energy Range ◽  
Center Of Mass ◽  
Mass Energy ◽  
Center Of Mass Energy

scholarly journals Upgrade of the KEDR detector DAQ system

2020 ◽  
Vol 245 ◽  
pp. 01004
Author(s):  
Dmitriy Maximov ◽  
Alexey Talyshev ◽  
Alexander Ruban ◽  
Alexey Kozyrev
Keyword(s):  
Energy Range ◽  
Wide Spectrum ◽  
Center Of Mass ◽  
Decision Time ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
Data Transfers ◽  
Trigger Decision ◽  
High Level ◽  
Planned Activities

The KEDR experiment is ongoing at the VEPP-4M e+e− collider at Budker INP in Novosibirsk. The collider center of mass energy range covers a wide spectrum from 2 to 11 GeV. Most of the up-to-date statistics were taken at the lower end of the energy range around the charmonia region. Planned activities at greater energies up to the bottomonia would lead to a significant increase of event recording rates and accelerator backgrounds, thus stressing the existing DAQ and trigger systems beyond their limits. The described DAQ upgrade plan includes: the redesign of the trigger electronics using modern components to improve the trigger decision time; the development of new readout processors using ethernet connections; new software for collecting events and electronics management; high level of parallelization of data transfers and events processing; improved reliability based on readout computing cluster with redundancy. The upgraded DAQ system is going to be very flexible and could be considered as a concept prototype of the projected BINP Super Charm-Tau Factory.

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