arXiv subjects

Giuseppe Mandaglio

Publications and source records attributed to Giuseppe Mandaglio.

9 recordsLinked to original sources

arXiv2024

Secondary beams at high-intensity electron accelerator facilities

The interaction of a high-current $O$(100~\textmu A), medium energy $O$(10\,GeV) electron beam with a thick target $O$(1m) produces an overwhelming shower of standard matter particles in addition to hypothetical Light Dark Matter particles. While most of the radiation (gamma, electron/positron, and neutron) is contained in the thick target, deep penetrating particles (muons, neutrinos, and light dark matter particles) propagate over a long distance, producing high-intense secondary beams. Using sophisticated Monte Carlo simulations based on FLUKA and GEANT4, we explored the characteristics of secondary muons and neutrinos and (hypothetical) dark scalar particles produced by the interaction of Jefferson Lab 11 GeV intense electron beam with the experimental Hall-A beam dump. Considering the possible beam energy upgrade, this study was repeated for a 20 GeV CEBAF beam.

physics.acc-ph↗

arXiv2022

First Simultaneous K$^-$p $\rightarrow (Σ^0/Λ) \, π^0$ Cross Sections Measurements at 98 MeV/c

We report the first simultaneous and independent measurements of the K$^{-}$p $\rightarrow Σ^0 \, π^{0}$ and K$^{-}$p $\rightarrow Λ\, π^{0}$ cross sections around 100 MeV/c kaon momentum. The kaon beam delivered by the DA$Φ$NE collider was exploited to detect K$^-$ absorptions on Hydrogen atoms, populating the gas mixture of the KLOE drift chamber. The precision of the measurements ($σ_{K^- p \rightarrow Σ^0 π^0} = 42.8 \pm 1.5 (stat.) ^{+2.4}_{-2.0}(syst.) \ \mathrm{mb}$ and $σ_{K^- p \rightarrow Λπ^0} = 31.0 \pm 0.5 (stat.) ^{+1.2}_{-1.2}(syst.) \ \mathrm{mb}\,$) is the highest yet obtained in the low kaon momentum regime.

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arXiv2020

$K^+Λ$(1405) photoproduction at the BGO-OD experiment

Since the discovery of the $Λ(1405)$, it remains poorly described by conventional constituent quark models, and it is a candidate for having an "exotic" meson-baryon or "penta-quark" structure, similar to states recently reported in the hidden charm sector. The $Λ(1405)$ can be produced in the reaction $γp \rightarrow K^+Λ(1405)$. The pure I=0 decay mode into $Σ^0π^0$ is prohibited for the mass-overlapping $Σ(1385)$. Combining a large aperture forward magnetic spectrometer and a central BGO crystal calorimeter, the BGO-OD experiment is ideally suited to measure this decay with the $K^+$ in the forward direction. Preliminary results are presented. *Supported by DFG (PN 388979758, 405882627).

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arXiv2020

Strangeness photoproduction at the BGO-OD experiment

The BGO-OD experiment at the University of Bonn's ELSA accelerator facility in Germany is ideally suited to investigate photoproduction at extreme forward angles. It combines a highly segmented BGO electromagnetic calorimeter at central angles and an open dipole magnetic spectrometer in the forward direction. This allows the detection of forward going kaons, and complex final states of mixed charge from hyperon decays. Current projects at the BGO-OD experiment include strangeness production of $γp \rightarrow K^+ Λ/Σ^0$ at forward angles, $K^0Σ^0$ with a deuteron target and $K^+Λ(1405)$ line shape and cross section measurements.

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arXiv2014

Entrance channel effects on the evaporation residue yields in reactions leading to the $^{220}$Th compound nucleus

The evaporation residue yields from compound nuclei $^{220}$Th formed in the $^{16}$O+$^{204}$Pb, $^{40}$Ar+$^{180}$Hf, $^{82}$Se+$^{138}$Ba, $^{124}$Sn+$^{96}$Zr reactions are analyzed to study the entrance channel effects by comparison of the capture, fusion and evaporation residue cross sections calculated by the combined dinuclear system (DNS) and advanced statistical models. The difference between evaporation residue (ER) cross sections can be related to the stages of compound nucleus formation or/and at its surviving against fission. The sensitivity of the both stages in the evolution of DNS up to the evaporation residue formation to the angular momentum of DNS is studied. The difference between fusion excitation functions are explained by the hindrance to complete fusion due to the larger intrinsic fusion barrier $B^*_{\rm fus}$ for the transformation of the DNS into a compound nucleus and the increase of the quasifission contribution due to the decreasing of quasifission barrier $B_{\rm qf}$ as a function of the angular momentum. The largest value of the ER residue yields in the very mass asymmetric $^{16}$O+$^{204}$Pb reaction is related to the large fusion probability and to the relatively low threshold of the excitation energy of the compound nucleus. Due to the large threshold of the excitation energy (35 MeV) of the $^{40}$Ar+$^{180}$Hf reaction, it produces less the ER yields than the almost mass symmetric $^{82}$Se+$^{138}$Ba reaction having the lowest threshold value (12 MeV).

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arXiv2013

Main restrictions in the synthesis of new superheavy elements: quasifission or/and fusion-fission

The synthesis of superheavy elements stimulates the effort to study the peculiarities of the complete fusion with massive nuclei and to improve theoretical models in order to extract knowledge about reaction mechanism in heavy ion collisions at low energies. We compare the theoretical results of the compound nucleus (CN) formation and evaporation residue (ER) cross sections obtained for the $^{48}$Ca+$^{248}$Cm and $^{58}$Fe+$^{232}$Th reactions leading to the formation of the isotopes A=296 and A=290, respectively, of the new superheavy element Lv (Z=116). The ER cross sections, which can be measured directly, are determined by the complete fusion and survival probabilities of the heated and rotating compound nucleus. That probabilities can not be measured unambiguously but the knowledge about them is important to study the formation mechanism of the observed products. For this aim, the $^{48}$Ca+$^{249}$Cf and $^{64}$Ni+$^{232}$Th reactions have been considered too. The use of the mass values of superheavy nuclei calculated in the framework of the macroscopic-microscopic model by Warsaw group leads to smaller ER cross section for all of the reactions (excluding the $^{64}$Ni+$^{232}$Th reaction) in comparison with the case of using the masses calculated by Peter Möller {\it et al}.

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arXiv2011

The high-lying $^6$Li levels at excitation energy around 21 MeV

The $^3$H+$^3$He cluster structure in $^6$Li was investigated by the $^3$H($α$,$^3$H $^3$He)n kinematically complete experiment at the incident energy $E_α$ = 67.2 MeV. We have observed two resonances at $E_x^*$ = 21.30 and 21.90 MeV which are consistent with the $^3$He($^3$H, $γ$)$^6$Li analysis in the Ajzenberg-Selove compilation. Our data are compared with the previous experimental data and the RGM and CSRGM calculations.

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arXiv2008

Role of the target orientation angle and orbital angular momentum in the evaporation residue production

The influence of the orientation angles of the target nucleus symmetry axis relative to the beam direction on the production of the evaporation residues is investigated for the $^{48}$Ca+$^{154}$Sm reaction as a function of the beam energy. At low energies ($E_{\rm c.m.}<$137 MeV), the yield of evaporation residues is observed only for collisions with small orientation angles ($α_T<45^0$). At large energies (about $E_{\rm c.m.}=$140--180 MeV) all the orientation angles $α_T$ can contribute to the evaporation residue cross section $σ_{ER}$ in the 10--100 mb range, and at $E_{c.m.}>$180 MeV $σ_{ER}$ ranges around 0.1--10 mb because the fission barrier for a compound nucleus decreases by increasing its excitation energy and angular momentum.

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arXiv2008

Bremsstrahlung emission during $α$-decay of $^{226}{\rm Ra}$

We obtained the spectrum of probability of the bremsstrahlung emission accompanying the $α$-decay of $^{226}{\rm Ra}$ (E$_α$=4.8 MeV) by measuring the $α$-$γ$ coincidences and using the model presented in our previous study on the $α-$decay of $^{214}{\rm Po}$ (E$_α$=7.7 MeV). We compare the experimental data with the quantum mechanical calculation and find a good agreement between theory and experiment. We discuss the differences between the photon spectra connected with the $α$-decay of the $^{226}{\rm Ra}$ and $^{214}{\rm Po}$ nuclei. For the two mentioned nuclei we analyze the bremsstrahlung emission contributions from the tunneling and external regions of the nucleus barrier into the total spectrum, and we find the destructive interference between these contributions. We also find that the emission of photons during tunneling of the $α$-particle gives an important contribution to the bremsstrahlung spectrum in the whole E$_γ$ energy range of the studied $^{226}$Ra nucleus.

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