Investigation of the synthesis of the unknown superheavy nuclei 309,312126

2019 ◽  
Vol 28 (07) ◽  
pp. 1950056 ◽  
Author(s):  
T. V. Nhan Hao ◽  
N. N. Duy ◽  
K. Y. Chae ◽  
N. Quang Hung ◽  
N. Nhu Le

In this paper, we applied the method developed by Santhosh and Safoora in [Phys. Rev. C  94 (2016) 024623; 95 (2017) 064611] to theoretically investigate the fusion, evaporation-residue (ER) and fission cross-sections of the synthesis of the unknown superheavy [Formula: see text]126 nuclei produced by using the [Formula: see text]Ni + [Formula: see text]Cf and [Formula: see text]Zn + [Formula: see text]Cm combinations. The charge asymmetry, mass asymmetry and fissility of the DiNuclear System (DNS) in the synthesis of the mentioned combinations are also estimated. The calculated results show that the ER cross-sections for the synthesis of the [Formula: see text]126 nuclei are predicted to be much less than 1.0[Formula: see text]fb. In particular, it has been found that there may exist a valley of the ER cross-sections in the synthesis of a superheavy [Formula: see text] element, which produces the [Formula: see text]126 isotope. Subsequently, a model for the mass dependence of the ER cross-section in the synthesis of the [Formula: see text]126 isotopes has been proposed for the first time. On the other hand, the quasi-fission process strongly dominates over the fusion in the two concerned interacting systems. The present results, together with those reported in the previous studies, indicate that the investigated projectile–target combinations are not capable for the synthesis of the [Formula: see text]126 isotopes due to tiny fusion cross-sections (about 2–3[Formula: see text]zb), which go beyond the limitations of available facilities. Further studies are thus recommended to search for alternative interacting systems. In conclusion, this work provides useful information for the synthesis of the gap isotopes [Formula: see text]126, which have not been well studied up to date.

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Claude Duhr ◽  
Falko Dulat ◽  
Bernhard Mistlberger

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.


2004 ◽  
Vol 13 (01) ◽  
pp. 293-300
Author(s):  
NEIL ROWLEY ◽  
NABILA GRAR

The creation of the nucleus of a superheavy element follows an extremely complex reaction path starting with the crossing of an external potential barrier (or distribution of barriers). This is followed by the evolution towards an equilibrated compound nucleus, which takes place in competition with pre-compound-nucleus fission (quasi-fission). Once formed the equilibrated compound nucleus must still survive against true fusion to yield a relatively long-lived evaporation residue. Much of this path is poorly understood, though recently, progress has been made on the role of the entrance-channel in quasi-fission. This will be briefly reported and a method proposed to measure the total capture cross section for such systems directly.


2009 ◽  
Vol 18 (04) ◽  
pp. 841-849 ◽  
Author(s):  
AVAZBEK NASIROV ◽  
GIOVANNI FAZIO ◽  
GIORGIO GIARDINA ◽  
GIUSEPPE MANDAGLIO ◽  
MARINA MANGANARO ◽  
...  

The decrease of the evaporation residue yields in reactions with massive nuclei is explained by an increase of the competition between quasifission and complete fusion processes and by the decrease of the survival probability of the heated and rotating nuclei against fission along the de-excitation cascade of the compound nucleus. The experimental data on the yields of evaporation residue, fusion-fission and quasifission fragments in the 48 Ca + 154 Sm reaction are analyzed in the framework of the combined theoretical method based on the dinuclear system concept and advanced statistical model. The measured yields of evaporation residues of the 48 Ca + 154 Sm reaction have been well reproduced and yields of fission fragments were analyzed using the partial fusion and quasifission cross sections calculated in the dinuclear system model. Such a way of calculation is used to find optimal conditions for the synthesis of the new element Z = 120 (A = 302) by studying the excitation functions of evaporation residues of the 54 Cr + 248 Cm , 58 Fe + 244 Pu , and 64 Ni + 238 U reactions. Our estimations show that the 54 Cr + 248 Cm reaction is preferable in comparison with the two others.


2005 ◽  
Vol 20 (02n03) ◽  
pp. 661-663
Author(s):  
◽  
FRÉDÉRIC KAPUSTA

Heavy b and c quark production in γγ collisions has been measured through semileptonic decays with the DELPHI detector at LEPII. The measured cross-sections are compared to NLO perturbative QCD calculations. The cross-section for b production is found to exceed QCD predictions. The K-lepton double tagging, used for the first time in γγ physics confirms this excess.


2013 ◽  
Vol 22 (08) ◽  
pp. 1350061 ◽  
Author(s):  
A. SULAKSONO

This paper studies the formation cross-sections of super heavy (SH) nuclei in some cold fusion reactions of radioactive neutron-rich projectiles with double-magic 208 Pb target. In this study, the cross-sections of capture, fusion and evaporation residues in one- and two-neutron (1n and 2n) channels are calculated by using neutron-rich Fe , Ni and Zn projectiles are compared to the cross-sections calculated using stable Fe , Ni and Zn projectiles. The heights of fusion barrier and their positions in all reactions considered in this study are also compared to the heights and positions calculated using the estimation method proposed by Dutt and Puri. For cold fusion reactions with stable Fe , Ni and Zn projectiles, the heights of fusion barrier and the cross-sections of evaporation residues in 1n and 2n channels are compared to their corresponding experimental data. In general, for reactions using projectiles with the same proton number, the neutron-rich projectile is found to yield relatively-heavier mass of SH nucleus and larger evaporation residue cross-section, compared to those of the corresponding stable projectiles. However, in certain reactions, the cross-sections of neutron-rich projectile can be slightly larger or slightly smaller than that of the corresponding stable projectile. This behavior is highly affected by the charge of projectile and the fission barrier of the formed compound nucleus (CN). In addition, the 292114 is found to be the heaviest compound nucleus formed in cold fusion reaction by using neutron-rich nuclei as the projectile, but the cross-section of evaporation residue in one-neutron channel is still around few pico barns (pb).


2016 ◽  
Vol 25 (01) ◽  
pp. 1650005
Author(s):  
D. Naderi

A combined dynamical model using concept of dinuclear systems (DNS) and one-dimensional (1D) Langevin equations was applied to investigate the effect of entrance channel on dynamics of heavy ions collision. The [Formula: see text]Si+[Formula: see text]Er, [Formula: see text]O+[Formula: see text]W and [Formula: see text]F+[Formula: see text]Ta reactions which formed the compound nucleus [Formula: see text]Pb have been considered to study this effect. We studied these reactions dynamically and calculated the ratio of evaporation residue cross-section to fusion cross-section [Formula: see text] as a tool for investigation of entrance channel effect. Results of combined model are compared with available experimental data and results of 1D Langevin equations. Obtained results based on combined model are in better agreement with experimental data in comparison with results of Langevin equations. We concluded for [Formula: see text]Si+[Formula: see text]Er and [Formula: see text]F+[Formula: see text]Ta reactions the results of combined model that support the quasi-fission process are different relative to Langevin dynamical approach, whereas for [Formula: see text]O+[Formula: see text]W system the two models give similar results.


2021 ◽  
Vol 129 (12) ◽  
pp. 1471
Author(s):  
И.В. Чернышова ◽  
Е.Э. Контрош ◽  
О.Б. Шпеник

Abstract– The interactions of low-energy electrons (<20 eV) with D-ribose molecules, namely, electron scattering and dissociative attachment, are studied. The results of these studies showed that the fragmentation of D-ribose molecules occurs effectively even at an electron energy close to zero. as well as in the energy range 5.50–9.50 eV. In the total cross section of electron scattering by molecules, resonance features at energies of 5.00–9.00 eV in the region of formation of ionic fragments C3H4O2–, C2H3O2–, OH–, associated with the destruction of molecular heterocycles, were experimentally discovered for the first time. The correlation of the features observed in the scattering and dissociative electron attachment cross sections is analyzed.


2020 ◽  
pp. 1-8
Author(s):  
H.C. Manjunatha ◽  
L. Seenappa ◽  
N. Sowmya ◽  
K.N. Sridhar

We have studied the 54–60Fe-induced fusion reactions to synthesize the superheavy nuclei296–302120 by studying the compound nucleus formation probability, survival probability, and evaporation residue cross-sections. The comparison of the evaporation residue cross-section for different targets reveals that the evaporation residue cross-section is larger for projectile target combination 58Fe+243Pu→301120. We have identified the most probable 58Fe-induced fusion reactions to synthesize superheavy nuclei 296–302120. The suggested reactions may be useful to synthesize the superheavy element Z = 120.


Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
O. Abdinov ◽  
...  

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.


2020 ◽  
Vol 108 (8) ◽  
pp. 593-602 ◽  
Author(s):  
Gaia Pupillo ◽  
Liliana Mou ◽  
Petra Martini ◽  
Micòl Pasquali ◽  
Alessandra Boschi ◽  
...  

AbstractDespite its insufficient availability, Copper-67 is currently attracting much attention for its enormous potential for cancer therapy as theranostic radionuclide. This work aims to accurately measure the unexplored cross section 70Zn(p,x)67Cu in the energy range 45–70 MeV and to evaluate its potential advantages in the case of high-intensity proton beams provided by compact cyclotrons. Thin target foils of enriched 70Zn were manufactured by lamination at the INFN-LNL and irradiated at the ARRONAX facility using the stacked-foils method. A radiochemical procedure for the separation of Cu, Ga and Zn contaminants and the isolation of 67Cu from the irradiated material was developed. The efficiency of the chemical processing was determined for each foil by monitoring the activity of selected tracer radionuclides (61Cu, 66Ga and 69mZn) through γ-spectrometry. Experimental data of the 70Zn(p,x)67Cu, 64Cu, 67Ga, 66Ga, 69mZn, 65Zn cross sections were measured for the first time in the energy range 45–70 MeV and compared with the theoretical results obtained by using the TALYS code. The 67Cu production yield by using enriched 70Zn thick targets was compared with the results obtained by using 68Zn targets in the same irradiation conditions.


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