scholarly journals Heavy target fragment yields in the interaction of 28 GeV protons with 238U

1983 ◽  
Vol 61 (4) ◽  
pp. 701-707 ◽  
Author(s):  
B. V. Jacak ◽  
W. Loveland ◽  
D. J. Morrissey ◽  
P. L. McGaughey ◽  
G. T. Seaborg
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Particle Emission ◽  
Nucleus Collision ◽  
Heavy Nuclei ◽  
Target Fragment ◽  
Heavy Target

The yields of target fragments from the interaction of 28 GeV protons with 238U have been measured, with special attention being given to those fragments with 160 ≤ A ≤ 200. From the measured fragment yields, isobarie production cross sections were calculated. Significant yields (σ(A) ~ 1–10 mb) of heavy target fragments (160 ≤ A ≤ 210) were found. These fragments are believed to be the non-fissioning survivors from the population of highly excited residual nuclei produced in the initial p-nucleus collision. A pedagogical calculation of the fission – particle emission competition shows how the initial highly excited heavy nuclei could evaporate ~20–50 particles while surviving fission competition.

scholarly journals Self-similarity approach for prediction and analysis of experiments at the accelerator complex NICA

2019 ◽  
Vol 204 ◽  
pp. 07003
Author(s):  
Elina G. Baldina ◽  
Anton A. Baldin
Keyword(s):  
Cross Sections ◽  
Quantitative Estimation ◽  
Production Cross ◽  
Meson Production ◽  
Accelerator Complex ◽  
Heavy Nuclei ◽  
Self Similarity ◽  
Nuclear Collisions ◽  
Relativistic Nuclear Collisions ◽  
The Given

The given functional self-similarity solution quantitatively describes angular, energy and A-dependences of inclusive production cross sections for hadrons in relativistic nuclear collisions. It is applied to quantitative estimation of D, as well as φ and J/ψ meson production in collider experiment at the NICA accelerator complex with heavy nuclei. The results can be used for optimization of kinematically registered parameters for investigation of collective phenomena.

KX-ray production cross sections for heavy target elements and14N,40Ar projectiles above the coulomb barrier

1986 ◽  
Vol 2 (1) ◽  
pp. 15-21 ◽  
Author(s):  
G. J. Balster ◽  
W. Huffelen ◽  
H. W. Wilschut ◽  
D. Chmielewska ◽  
Z. Sujkowski
Keyword(s):  
Cross Sections ◽  
Coulomb Barrier ◽  
Production Cross ◽  
Heavy Target

scholarly journals New studies and a short review of heavy neutron-rich transfer products

2020 ◽  
Vol 56 (9) ◽  
Author(s):  
H. M. Devaraja ◽  
S. Heinz ◽  
D. Ackermann ◽  
T. Göbel ◽  
F. P. Heßberger ◽  
...  
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Short Review ◽  
Heavy Nuclei ◽  
Model Calculations ◽  
Nucleon Transfer ◽  
Shell Effects ◽  
Fragmentation Reactions ◽  
Nuclear Shell ◽  
Nuclear Shell Effects

Abstract We present new results on multi-nucleon transfer reactions in low-energy collisions of $$^{48}\hbox {Ca}+{}^{238}\hbox {U}$$ 48 Ca + 238 U measured at the velocity filter SHIP of GSI Helmholtz Centre, where we observed around 90 different nuclides from Tl to Am ($$Z=$$ Z = 81–95). We followed the idea to use uranium targets for the synthesis of neutron-rich MNT products, particularly in the region below lead, which was triggered by model calculations. The $$\gamma $$ γ , $$\alpha $$ α and spontaneous fission activities of the populated nuclides have been analyzed for their identification. The cross-sections of the observed isotopes for elements $$Z = $$ Z = 81–93 as a function of their mass number have been investigated. Excitation energy, total kinetic energy and the influence of nuclear shell effects on the production cross-sections of the observed transfer products have been studied. Also we present a compact review and comparative analysis of various multi-nucleon transfer and fragmentation reactions which are aimed at the synthesis of neutron-rich nuclides along the $$N=126$$ N = 126 shell closure in heavy nuclei.

scholarly journals Eighty years of research on super-heavy nuclei

2018 ◽  
Vol 182 ◽  
pp. 02054 ◽  
Author(s):  
Sigurd Hofmann
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Heavy Ion ◽  
Experimental Investigations ◽  
Heavy Nuclei ◽  
Open Questions ◽  
Fission Barriers ◽  
Nuclear Shell ◽  
Closed Shells ◽  
Super Heavy Nuclei

Professor Walter Greiner, our mentor, colleague, and friend, passed away in the age of eighty. During his lifetime, the search for elements beyond uranium started and elements up to the so far heaviest one with atomic number 118 were discovered. In this talk I will present a short history from early searches for ‘trans-uraniums’ up to the production and safe identification of shell-stabilized ‘Super-Heavy Nuclei’ (SHN). The nuclear shell model reveals that these nuclei should be located in a region with closed shells for the protons at Z = 114, 120 or 126 and for the neutrons at N = 184. The outstanding aim of experimental investigations is the exploration of this region of spherical SHN. Systematic studies of heavy ion reactions for the synthesis of SHN revealed production cross-sections which reached values down to one picobarn and even below for the heaviest species. The systematics of measured cross-sections can be understood only on the basis of relatively high fission barriers as predicted for nuclei in and around the island of SHN. A key role in answering some of the open questions plays the synthesis of isotopes of element 120. Attempts aiming for synthesizing this element at the velocity filter SHIP will be reported.

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.

Formation of α clusters in dilute neutron-rich matter

Science ◽  
2021 ◽  
Vol 371 (6526) ◽  
pp. 260-264 ◽  
Author(s):  
Junki Tanaka ◽  
Zaihong Yang ◽  
Stefan Typel ◽  
Satoshi Adachi ◽  
Shiwei Bai ◽  
...  
Keyword(s):  
Cross Sections ◽  
Cluster Formation ◽  
Reaction Cross ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Heavy Nuclei ◽  
Α Decay ◽  
Neutron Skin Thickness ◽  
Reaction Cross Sections ◽  
Α Particles

The surface of neutron-rich heavy nuclei, with a neutron skin created by excess neutrons, provides an important terrestrial model system to study dilute neutron-rich matter. By using quasi-free α cluster–knockout reactions, we obtained direct experimental evidence for the formation of α clusters at the surface of neutron-rich tin isotopes. The observed monotonous decrease of the reaction cross sections with increasing mass number, in excellent agreement with the theoretical prediction, implies a tight interplay between α-cluster formation and the neutron skin. This result, in turn, calls for a revision of the correlation between the neutron-skin thickness and the density dependence of the symmetry energy, which is essential for understanding neutron stars. Our result also provides a natural explanation for the origin of α particles in α decay.

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