We perform Glauber model calculations of the antiproton-nucleus elastic and quasielastic scattering and absorption in the beam momentum range $\sim 0.5\div10$ GeV/c. A good agreement of our calculations with available LEAR data and with earlier Glauber model studies of the $\bar p A$ elastic scattering allows us to make predictions at the beam momenta of $\sim 10$ GeV/c, i.e. at the regime of the PANDA experiment at FAIR. The comparison with the proton-nucleus elastic scattering cross sections shows that the diffractive minima are much deeper in the $\bar p A$ case due to smaller absolute value of the ratio of the real-to-imaginary part of the elementary elastic amplitude. Significant polarization signal for $\bar p A$ elastic scattering at 10 GeV/c is expected. We have also revealed a strong dependence of the $\bar p A$ absorption cross section on the slope parameter of the transverse momentum dependence of the elementary $\bar pN$ amplitude. The $\bar p A$ optical potential is discussed.
Studying antiproton scattering by nuclei (atoms) in the range of low energies, we found out that the increase in the antiproton-nucleus scattering amplitude through Coulomb interaction provides the possibility to investigate spin-dependent processes accompanying the interaction of antiprotons with nuclei (polarized or unpolarized) by means of mirror reflection of antiprotons from the vacuum-matter boundary, diffraction and channeling (surface diffraction and channeling) of antiprotons in crystals.
We study the production of charmed baryons in the antiproton-proton and antiproton-nucleus interactions within a fully covariant model that is based on an effective Lagrangian approach. The baryon production proceeds via the $t$-channel $D^0$ and $D^{*0}$ meson-exchange diagrams. We have also explored the production of the charm-baryon hypernucleus $^{16}_{Λ_c^+}$O in the antiproton - $^{16}$O collisions. For antiproton beam momenta of interest to the ${\bar P}ANDA$ experiment, the 0$^\circ$ differential cross sections for the formation of $^{16}_{Λ_c^+}$O hypernuclear states with simple parti…
Previous analytical formulas in the Glauber model for high-energy nucleus-nucleus collisions developed by Wong are utilized and extended to study antiproton-nucleus annihilations for both high and low energies, after taking into account the effects of Coulomb and nuclear interactions, and the change of the antiproton momentum inside a nucleus. The extended analytical formulas capture the main features of the experimental antiproton-nucleus annihilation cross sections for all energies and mass numbers. At high antiproton energies, they exhibit the granular property for the lightest nuclei and t…
We study the strangeness production in antiproton-nucleus collisions at the beam momenta from 200 MeV/c to 15 GeV/c within the Giessen Botzmann-Uehling-Uhlenbeck (GiBUU) transport model. The GiBUU model contains a very detailed description of the underlying antinucleon-nucleon cross sections, in-particular, of the strangeness production channels. We compare our calculations with the bubble chamber data on Λ- and K^0_S-production in antiproton-nucleus collisions and with the earlier intranuclear cascade calculations. The contributions of the various partial channels to the hyperon production ar…
Elastic scattering of antiprotons off $^4$He, $^{12}$C, and $^{16,18}$O is described for the first time with a totally microscopic approach based on the calculation of an optical potential (OP) describing the antiproton-target interaction. The OP is derived using the recent antiproton-nucleon ($\bar{p}N$) chiral interaction to calculate the $\bar{p}N$ $t$ matrix, while the target densities are computed with the ab initio no-core shell model using chiral interactions as well. Our results are in a good agreement with the existing experimental data and the results computed at different chiral ord…
We present the analysis of experimental data on forward antiproton production on nuclei. The calculations are done in the framework of a folding model which takes properly into account both incoherent direct proton-nucleon and cascade pion-nucleon antiproton production processes as well as internal nucleon momentum distribution. The effective antiproton-nucleon cross section in nuclear matter and the imaginary part of the antiproton nuclear optical potential are estimated to be 25-45 mb and -(38-56) MeV at normal nuclear matter density, respectively. The results of the performed analysis evide…
The influence of Coulomb interaction on the phenomenon of "optical" spin rotation of negatively charged particles (antiprotons, etc.) moving in matter with polarized nuclei is considered. It is shown that because the density of the antiproton (negative hyperon) wave function on the nucleus increases, the spin precession frequency grows as the particle decelerates. As a result, spin rotation of negatively charged particles becomes observable despite their rapid deceleration. This provides information about the spin--dependent part of the amplitude of coherent elastic zero--angle scattering in t…
We calculate, in a systematic way, the enhancement effect on antiproton-proton and antiproton-nucleus annihilation cross sections at low energy due to the initial state electrostatic interaction between the projectile and the target nucleus. This calculation is aimed at future comparisons between antineutron and antiproton annihilation rates on different targets, for the extraction of pure isospin channels.
The exclusive production of hyperon-antihyperon pairs close to their production threshold in antiproton - nucleus collisions offers a unique and hitherto unexplored opportunity to elucidate the behaviour of antihyperons in nuclei. For the first time we analyse these reactions in a microscopic transport model using the the Gießen Boltzmann-Uehling-Uhlenbeck transport model. The calculation take the delicate interplay between the strong absorption of antihyperons, their rescattering and refraction at the nuclear surface as well as the Fermi motion of the struck nucleon into account. We find a su…
Antiproton scattering off $^3\He$ and $^4\He$ targets is considered at beam energies below 300 MeV within the Glauber-Sitenko approach, utilizing the $\bar N N$ amplitudes of the Jülich model as input. A good agreement with available data on differential $\bar p ^4\He$ cross sections and on $\bar p ^3\He$ and $\pbar ^4\He$ reaction cross sections is obtained. Predictions for polarized total $\bar p ^3$He cross sections are presented, calculated within the single-scattering approximation and including Coulomb-nuclear interference effects. The kinetics of the polarization buildup is discussed.
The influence of Coulomb distortion on the polarization transfer in elastic proton and antiproton electron scattering at low energies is calculated in a distorted wave Born approximation. For antiproton electron scattering Coulomb effects reduce substantially the spin transfer cross section compared to the plane wave Born approximation whereas for proton electron scattering they lead to a dramatic increase for kinetic proton lab energies below about 20 keV.
One of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force since acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, we have no direct knowledge of the nuclear force between antinucleons. Here, we study antiproton pair correlations among data taken by the ST…
We examine the production of open charm in antiproton annihilation on finite nuclei. The enhancement of the subthreshold production cross section, even in a nucleus as light as carbon, should provide a clean signature of the reduction in the masses of these mesons in-medium. We also show that a careful analysis of the $D^+$ and $D^-$ spectra can yield important information on the cross section for $D^{\pm}N$ scattering.
Recent measurements of the cosmic ray (CR) antiproton flux have been shown to challenge existing CR propagation models. It was shown that the reacceleration models designed to match secondary to primary nuclei ratios (e.g., boron/carbon) produce too few antiprotons. Matching both the secondary to primary nuclei ratio and the antiproton flux requires artificial breaks in the diffusion coefficient and the primary injection spectrum suggesting the need for other approaches. In the present paper we discuss one possibility to overcome these difficulties. Using the measured antiproton flux AND B/C r…
On the basis of a dynamical Relativistic Mean Field (RMF) model we study the response of a nucleus on the antiproton implanted in its interior. We solve the Vlasov equation for the antiproton-nuclear system and show assuming a moderately attractive antiproton optical potential that the compressed state is formed on a rather short time scale of about 4-10 fm/c. The evolution of the system after antiproton annihilation is simulated using the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model. Finally, several sensitive observables to the antiproton annihilation in a compressed nuclear c…
We compare data of antineutron and antiproton annihilation cross sections on different targets at very low energies. After subtracting Coulomb effects, we observe that the ratio between the antineutron proton and antiproton proton annihilation cross sections is an oscillating function of the energy at momenta smaller 300 MeV/c. This nontrivial behavior is confirmed by the analysis of the relative number of antiproton-neutron and antiproton-proton annihilations in nuclei. We show that a part of the strong shadowing phenomena in antiproton-nucleus annihilations can be explained in terms of this …
We propose to use antiprotons to investigate the sizes of stable and neutron-rich exotic nuclei by measurements of the $\pbar A$ absorption cross section along isotopic chains in inverse kinematics. The expected effects are studied theoretically in a microscopic model. The $\pbar U$ optical potentials are obtained by folding free space $\pbar N$ scattering amplitudes with HFB ground state densities and solving the scattering equations by direct integration. The mass dependence of absorption cross sections is found to follow closely the nuclear root-mean-square radii. The total absorption cross…
Recent measurements of very low-energy ($p_{L}<100$ MeV/c) $\bar p$ annihilation on light nuclei reveal apparent suppression of annihilation upon increasing the atomic charge $Z$ and mass number $A$. Using $\bar p$-nucleus optical potentials $V_{\rm opt}$, fitted to $\bar p$-atom energy-shifts and -widths, we resolve this suppression as due to the strong effective repulsion produced by the very absorptive $V_{\rm opt}$. The low-energy $\bar p$-nucleus wavefunction is kept substantially outside the nuclear surface and the resulting reaction cross section saturates as function of the strength of…
We present a new energy-dependent partial-wave analysis of all antiproton-proton elastic and charge-exchange scattering data below 925 MeV/c antiproton laboratory momentum. The long-range parts of the chiral one- and two-pion exchange interactions are included exactly. The short-range interactions, including the coupling to the mesonic annihilation channels, are parametrized by a complex boundary condition at a radius of r=1.2 fm. The updated database, which includes significantly more high-quality charge-exchange data, contains 3749 scattering data. The fit results in chi^2_min/N_df=1.048, wh…
We investigate the polarization parameters in low-energy antiproton-proton elastic ($\bar{p}p\rightarrow\bar{p}p$) and charge-exchange ($\bar{p}p\rightarrow\bar{n}n$) scattering. The predictions for unmeasured observables are based on our new energy-dependent partial-wave analysis of all antiproton-proton scattering data below 925 MeV/$c$ antiproton laboratory momentum, which gives an optimal description of the existing database. Sizable and remarkable spin effects are observed, in particular for charge-exchange scattering. These result from the spin dependence of the long- and medium-range on…
Spin-dependent total pbar-d cross sections are considered using the optical theorem. For this aim the full spin dependence of the forward pbar-d elastic scattering amplitude is considered in a model independent way. The single-scattering approximation is used to relate this amplitude to the elementary amplitudes of pbar-p and pbar-n scattering and the deuteron form factor. A formalism allowing to take into account Coulomb-nuclear interference effects in polarized pbar-d cross sections is developed. Numerical calculations for the polarized total pbar-d cross sections are performed at beam energ…
We report on self-consistent calculations of $\bar{p}$ quasi-bound states in selected nuclei performed within the relativistic mean-field (RMF) model employing $\bar{p}$ coupling constants tuned to reproduce $\bar{p}$-atom data. We confirmed considerable polarization of the nuclear core induced by the antiproton. The $\bar{p}$ annihilation was treated dynamically, taking into account the reduced phase space in the nuclear medium as well as the compressed nuclear density. The energy available for the annihilation products was evaluated self-consistently, considering additional energy shift due …
The production of charmonia in the antiproton-nucleus reactions at $p_{\rm lab}=3-10$ GeV/c is studied within the Glauber model and the generalized eikonal approximation. The main reaction channel is charmonium formation in an antiproton-proton collision. The target mass dependence of the charmonium transparency ratio allows to determine the charmonium-nucleon cross section. The polarization effects in the production of $χ_{c2}$ states are evaluated.
We performed fully self-consistent calculations of $\bar{p}$-nuclear bound states within the relativistic mean-field (RMF) model. The G-parity motivated $\bar{p}$-meson coupling constants were adjusted to yield potentials consistent with $\bar{p}$-atom data. We confirmed large polarization effects of the nuclear core caused by the presence of the antiproton. The $\bar{p}$ absorption in the nucleus was incorporated by means of the imaginary part of a phenomenological optical potential. The phase space reduction for the $\bar{p}$ annihilation products was taken into account. The corresponding $\…
The recent experimental data obtained by the OBELIX group on $\bar{p}$D and $\bar{p}^4$He total annihilation cross sections are analyzed. The combined analysis of these data with existing antiprotonic atom data allows, for the first time, the imaginary parts of the S-wave scattering lengths for the two nuclei to be extracted. The obtained values are: $Im a^{sc}_0 = [- 0.62 \pm 0.02 ({stat}) \pm 0.04 ({sys})] fm$ for $\bar{p}$D and $Im a^{sc}_0 = [- 0.36\pm 0.03({stat})^{+0.19}_{-0.11}({sys})] fm$ for $\bar{p}^4$He. This analysis indicates an unexpected behaviour of the imaginary part of the $\…
We performed fully self-consistent calculations of $\bar{p}$-nuclear bound states using a complex ${\bar p}$-nucleus potential accounting for $\bar{p}$-atom data. While the real part of the potential is constructed within the relativistic mean-field (RMF) model, the $\bar{p}$ annihilation in the nuclear medium is described by a phenomenological optical potential. We confirm large polarization effects of the nuclear core caused by the presence of the antiproton. The ${\bar p}$ annihilation is treated dynamically, taking into account explicitly the reduced phase space for annihilation from deepl…
Antiproton-induced reactions on nuclei at the beam energies from hundreds MeV up to several GeV provide an excellent opportunity to study interactions of the antiproton and secondary particles (mesons, baryons and antibaryons) with nucleons. Antiproton projectile is unique in the sense that most of annihilation particles are relatively slow in the target nucleus frame. Hence, the prehadronic effects do not much influence their interactions with the nucleons of the nuclear residue. Moreover, the particles with momenta less than about 1 GeV/c are sensitive to the nuclear mean field potentials. T…
A brief review of antiproton--nucleus physics is presented. Some topics are related to early LEAR experiments, and others to more recent measurements or proposals. These include: exotic molecules, elastic and inelastic scattering, deep annihilation, strangeness production, neutron--antineutron oscillations, halo nuclei, antiproton production in nuclear reactions etc.
A successful unified description of $\bar p$ nuclear interactions near E=0 is achieved using a $\bar p$ optical potential within a folding model, $V_{\rm opt} \sim \bar v * ρ$, where a $\bar p p$ potential $\bar v$ is folded with the nuclear density $ρ$. The potential $\bar v$ fits very well the measured $\bar p p$ annihilation cross sections at low energies ($p_L < 200$ MeV/c) and the $1s$ and $2p$ spin-averaged level shifts and widths for the $\bar p$H atom. The density-folded optical potential $V_{\rm opt}$ reproduces satisfactorily the strong-interaction level shifts and widths over the en…
We investigate the structure and formation of charmed meson--nucleus systems, with the aim of understanding the charmed meson--nucleon interactions and the properties of the charmed mesons in the nuclear medium. The $\bar{D}$ mesic nuclei are of special interest, since they have tiny decay widths due to the absence of strong decays for the $\bar{D} N$ pair. Employing an effective model for the $\bar{D} N$ and $D N$ interactions and solving the Klein--Gordon equation for $\bar{D}$ and $D$ in finite nuclei, we find that the $D^{-}$-${}^{11}\rm{B}$ system has $1 s$ and $2p$ mesic nuclear states a…
Experimental annihilation cross sections of antineutrons and antiprotons at very low energies are compared. Features of Coulomb focusing are observed for $\bar p$ annihilation on protons. Direct comparisons for heavier targets are not straightforward due to lack of overlap between targets and energies of experimental results for $\bar p$ and $\bar n$. Nevertheless, the annihilation cross sections for $\bar n$ on nuclei cannot be described by an optical potential that fits well all the available data on $\bar p$ interactions with nuclei. Comparisons made with the help of this potential reveal i…
The nuclear interactions of atomic and low energy antiprotons are studied. Measurements of level shifts and widths in the lightest elements are analyzed and compared with new results obtained in heavy nuclei. Simple geometric properties of antiproton - nucleus interactions are demonstrated. Upon this background one finds some anomalies that indicate strong energy dependence in the subthreshold antiproton - nucleon interactions. The use of of antiproton in studies of the nuclear surface is briefly discussed.
Assuming a~simple spherical relativistic mean field model of the nucleus, we estimate the width of the antiproton--neutron annihilation ($Γ_n$) and the width of antiproton--proton ($Γ_p$) annihilation, in an antiprotonic atom system. This allows us to determine the halo factor $f$, which is then discussed in the context of experimental data obtained in measurements recently done on LEAR utility at CERN. Another quantity which characterizes the deviation of the average nuclear densities ratio from the corresponding ratio of the homogeneous densities is introduced too. It was shown that it is al…
The Giessen Boltzmann-Uehling-Uhlenbeck transport model is extended and applied to the antiproton-nucleus interactions in a wide beam momentum range. The model calculations are compared with the experimental data on $\bar p$-absorption cross sections on nuclei with an emphasis on extraction of the real part of an antiproton optical potential. The possibility of the cold compression of a nucleus by an antiproton in-flight is also considered.
A microscopic optical potential (OP) is derived from NN chiral potentials at the first-order term within the spectator expansion of the multiple scattering theory and adopting the impulse approximation. The performances of our OP are compared with those of a phenomenological OP in the description of elastic proton scattering data on different isotopic chains. An analogous scheme is adopted to construct a microscopic OP for elastic antiproton-nucleus scattering. The results of our OPs are in reasonably good agreement with the experimental data, for both elastic proton and antiproton-nucleus sca…
We update our recent analysis of pbar-d scattering, performed within the Glauber theory including the single- and double pbar-N scattering mechanisms. Specifically, now we consider also Nbar-N amplitudes from a new partial-wave analysis of pbar-p scattering data. Predictions for differential cross sections and the spin observables A_y^d, A_y^pbar, A_xx, A_yy are presented for antiproton beam energies between 50 and 300 MeV. Total polarized cross sections are calculated utilizing the optical theorem. The efficiency of the polarization buildup for antiprotons in a storage ring is investigated.
We study the $\bar D D$ (${\bar D}^0 D^0$ and $D^-D^+$) charm meson pair production in antiproton (${\bar p}$) induced reactions on nuclei at beam energies ranging from threshold to several GeV. Our model is based on an effective Lagrangian approach that has only the baryon-meson degrees of freedom and involves the physical hadron masses. The reaction proceeds via the $t$-channel exchanges of $Λ_c^+$, $Σ_c^+$, and $Σ_c^{++}$ baryons in the initial collision of the antiproton with one of the protons of the target nucleus. The medium effects on the exchanged baryons are included by incorporating…
A general algorithm for handling the energy dependence of hadron-nucleon amplitudes in the nuclear medium, consistently with their density dependence, has been recently applied to antikaons, eta mesons and pions interacting with nuclei. Here we apply this approach to antiprotons below threshold, analyzing experimental results for antiprotonic atoms across the periodic table. It is also applied to antiproton and antineutron interaction with nuclei up to 400 MeV/c, comparing with elastic scattering and annihilation cross sections. The underlying $\bar pN$ scattering amplitudes are derived from t…
Antiproton annihilations on nuclei provide a very interesting way to study the behaviour of strange particles in the nuclear medium. In low energy $\bar p$ annihilations, the hyperons are produced mostly by strangeness exchange mechanisms. Thus, hyperon production in $\bar p A$ interactions is very sensitive to the properties of the antikaon-nucleon interaction in nuclear medium. Within the Giessen Boltzmann-Uehling-Uhlenbeck transport model (GiBUU), we analyse the experimental data on $Λ$ and $K^0_S$ production in $\bar p A$ collisions at $p_{\rm lab}=0.2-4$ GeV/c. A satisfactory overall agre…
In the reaction of the antiproton-deuteron electromagnetic annihilation pbar + d --> e+e-n the value of the invariant mass M of the (e+e-) pair can be near or below the (pbar p) mass even for enough high momentum of incident antiproton. This allows to access the proton electromagnetic form factors in the time-like region of q^2 near the (pbar p) threshold. We estimate the cross section dsigma(pbar + d --> e+e-n)/dM for an antiproton beam momentum of 1.5 GeV/c. We find that near the (pbar p) threshold this cross section is about 1 pb/MeV. The case of heavy nuclei target is also discussed. Eleme…
Contrary to the reaction pbar + p --> e+ e- with a high momentum incident antiproton on a free target proton at rest, in which the invariant mass M of the (e+ e-) pair is necessarily much larger than the (pbar p) mass, in the reaction pbar + d --> n e+ e- the value of M can take values near or below the (pbar p) mass. In the antiproton-deuteron electromagnetic annihilation, this allows to access the proton electromagnetic form factors in the time-like region of q^2 near the (pbar p) threshold. We estimate the cross section dsigma(pbar +d --> e+ e- n)/dM for an antiproton beam momentum of 1.5 G…
We calculate the subthreshold production of antiprotons in the Lorentz-covariant RBUU approach employing a weighted testparticle method to treat the antiproton propagation and absorption nonperturbatively. We find that the pbar differential cross sections are highly sensitive to the baryon and antiproton selfenergies in the dense baryonic environment. Adopting the baryon scalar and vector selfenergies from the empirical optical potential for proton-nucleus elastic scattering and from Dirac-Brueckner calculations at higher density rho > rho_0 we examine the differential pbar spectra as a functi…
Formation mechanism of fragments with strangeness in collisions of antiprotons on nuclei has been investigated within the Lanzhou quantum molecular dynamics (LQMD) transport approach combined with a statistical model (GEMINI) for describing the decays of excited fragments. Production of strange particles in the antiproton induced nuclear reactions is modeled within the LQMD model, in which all possible reaction channels such as elastic scattering, annihilation, charge exchange and inelastic scattering in antibaryon-baryon, baryon-baryon and meson-baryon collisions have been included. A coalesc…
We study the possibility of producing a new kind of nuclear systems which in addition to ordinary nucleons contain a few antibaryons (antiproton, antilambda, etc.). The properties of such systems are described within the relativistic mean-field model by employing G-parity transformed interactions for antibaryons. Calculations are first done for infinite systems and then for finite nuclei from He to Pb. It is demonstrated that the presence of a real antibaryon leads to a strong rearrangement of a target nucleus resulting in a significant increase of its binding energy and local compression. Not…
Antiproton-nucleon ($\bar{p}N$) total cross sections are typically 3-4 times larger than the $NN$ ones at incident energies from a few hundreds to thousands MeV. We investigate antiproton-nucleus scattering as it could work as a probe of the nuclear structure giving the sensitivity differently from a proton probe. High-energy antiproton-nucleus reactions are reasonably described by the Glauber model with a minimal profile function that reproduces the $\bar{p}N$ and $\bar{p}$-$^{12}$C cross section data. In contrast to the proton-nucleus scattering, we find that the complete absorption occurs e…
The elastic scattering, Stark transitions and Coulomb deexcitation of excited antiprotonic hydrogen atom in collisions with hydrogenic atom have been studied in the framework of the fully quantum-mechanical close-coupling method for the first time. The total cross sections $σ_{nl \to n'l'}(E)$ and averaged on the initial angular momentum $l$ cross sections $σ_{n\to n'}(E)$ have been calculated for the initial states of $(\bar{p}p)_{n}$ atoms with the principal quantum number $n=3 - 14 $ and at the relative energies $E=0.05 - 50$ eV. The energy shifts of the $ns$ states due to the strong intera…
Elastic pbar-d scattering is studied within the Glauber theory based on the single- and double pbar-N scattering mechanisms. The full spin dependence of the elementary pbar-N scattering amplitudes is taken into account and both the S- and D-wave components of the deuteron are considered. The treatment of the spin dependence is done in a (properly modified) formalism developed recently by Platonova and Kukulin for the pd -> pd scattering process. Predictions for differential cross sections and the spin observables A_y^d, A_y^pbar, A_xx, A_yy are presented for antiproton beam energies between 50…
The influence on fusion of coupling to the breakup process is investigated for reactions where at least one of the colliding nuclei has a sufficiently low binding energy for breakup to become an important process. Elastic scattering, excitation functions for sub-and near-barrier fusion cross sections, and breakup yields are analyzed for $^{6,7}$Li+$^{59}$Co. Continuum-Discretized Coupled-Channels (CDCC) calculations describe well the data at and above the barrier. Elastic scattering with $^{6}$Li (as compared to $^{7}$Li) indicates the significant role of breakup for weakly bound projectiles. …
We present theoretical predictions for electron scattering on oxygen and calcium isotopic chains. The calculations are done within the framework of the distorted-wave Born approximation and the proton and neutron density distributions are evaluated adopting a relativistic Dirac-Hartree model. We present results for the elastic and quasi-elastic cross sections and for the parity-violating asymmetry. As a first step, the results of the models are tested in comparison with some of the data available for elastic and quasi-elastic scattering on 16O and 40Ca nuclei. Then, the evolution of some nucle…
We present the first example of a rigorous uncertainty quantification on elastic Nucleus-Nucleus scattering at energies near the Coulomb barrier. Experimental data has been analyzed using an energy dependent effective optical model potential with physical constraints imposed. We confirm the compatibility of these uncertainties with the well known Coulomb threshold anomaly, explained in terms of a dispersive relation, and contrast our results with previous analyses that suggest otherwise.
We show a relationship between elastic electron scattering observables and the elastic neutrino cross section that provides a straightforward determination of the latter from experimental data of the former and relates their uncertainties. An illustration of this procedure is presented using a Hartree-Fock mean field for the nuclear structure of a set of even-even nuclear targets, using the spectra of the neutrinos produced in pion decay at rest. We also analyze the prospects to measure the incoherent axial contribution to the neutrino elastic scattering in odd targets.
A parton picture of inclusive quasi-elastic electron-nucleus scattering, where individual nucleons are treated as (non point-like) partons of the nucleus, is presented. All the necessary target-mass corrections to asymptotic scaling are evaluated and a new scaling variable is obtained. Recent inclusive data from Jefferson Lab are analyzed and shown to scale in terms of the new variable. The new approach allows to extract in a model-independent way the nucleon light-cone momentum distribution in the nucleus.
The method of fusion barrier distribution has been widely used to interpret the effect of nuclear structure on heavy-ion fusion reactions around the Coulomb barrier. We discuss a similar, but less well known, barrier distribution extracted from large-angle quasi-elastic scattering. We argue that this method has several advantages over the fusion barrier distribution, and offers an interesting tool for investigating unstable nuclei.
Starting from the Feynman diagram representation of multiple scattering we consider the polarized $χ_c$(1P)-charmonia production in antiproton-nucleus reactions close to the threshold ($p_{\rm lab}=5-7$ GeV/c). The rescattering and absorption of the incoming antiproton and outgoing charmonium on nucleons are taken into account, including the possibility of the elastic and nondiagonal (flavor-conserving) scattering $χ_{cJ} N \to χ_{cJ^\prime} N$, $J,J^\prime=0,1,2$. The elementary amplitudes of the latter processes are evaluated by expanding the physical $χ_c$-states in the Clebsch-Gordan serie…
The observed cross sections of quasi-elastic scattering of 6He, 7Be, and 8B nuclei by 12C nuclei are described within the framework of the diffraction nuclear model and the model of nucleus-nucleus scattering in the high-energy approximation with a double folding potential, for intermediate energies of the incident particles. The calculations make use of realistic distributions of nucleon densities and take account of the Coulomb interaction and inelastic scattering with excitation of low-lying collective states of the target.
