The elastic backward proton-deuteron scattering is analyzed including relativistic effects in the deuteron and the mechanism of this reaction which includes the graphs corresponding to the emission, rescattering and absorption of the virtual pion by a deuteron nucleon in addition to the one-nucleon exchange graph. It allows one to obtain a rather satisfactory description of all the experimental data on the differential cross section, tensor analyzing power of the deuteron and transfer polarization in this reaction.
We study how d+3He beckward elastic scattering is connected with momentum distribution of the deuteron in 3He. With this aim th relativistic calculations in the framework of proton exchange is investigated. We also consider possible reaction mechanisms beyond the proton exchange
The elastic proton-deuteron backward reaction is analyzed within a covariant approach based on the Bethe-Salpeter equation with realistic meson-exchange interaction. Lorentz boost and other relativistic effects in the cross section and spin correlation observables, like tensor analyzing power and polarization transfer etc., are investigated in explicit form. Results of numerical calculations for a complete set of polarization observables are presented.
The tensor analyzing power $T_{20}$ and the polarization transfer coefficients $κ_0 (= 3/2 K_y^y)$ and $K_{xz}^y$ are investigated for dp backward elastic scattering by the invariant-amplitude method. Discrepancies between the conventional calculations and the experimental data on $T_{20}$ and $κ_0$ at high and intermediate energies are mostly dissolved by including imaginary parts in the amplitudes. The quantity $K_{xz}^y$ is shown to be useful in criticizing nuclear force assumptions.
The elastic backward proton-deuteron scattering is analyzed within a covariant approach based on the Bethe-Salpeter equation with realistic meson-exchange interaction. Contributions of the one-nucleon and one-pion exchange mechanisms to the cross section and polarization observables are investigated in explicit form. Results of numerical calculations for the cross section, tensor analyzing power and spin transfers are presented. The one-pion exchange contribution is essential for describing the spin averaged cross section, while in polarization observables it is found to be less important.
It is shown that owing to a dominance of $np-$pair transfer mechanism of backward elastic $p^3He$- scattering for incident proton kinetic energies $T_p>1$ GeV the cross section of this process is defined mainly by the values of the Faddeev component of the wave function of $^3He$ nucleus, $ϕ^{23}({\bf q}_{23}, {\bf p}_1)$, at high relative momenta $q_{23}> 0.6 GeV/c$ of the NN-pair in the $^1S_0-$ state and at low spectator momenta $p_1\sim 0-0.2$ GeV/c.
The elastic backward proton-deuteron scattering is analyzed within a covariant approach based on the invariant expansion of the reaction amplitude. The relativistic invariant equations for all the polarization observables are presented. Within the impulse approximation the relation of the tensor analyzing power $T_{20}$ and the polarization transfer $κ_0$ to $P$-wave components of the deuteron wave function is found. The comparison of the theoretical calculations with experimental data is presented. An experimental verification of the reaction mechanism is suggested by constructing some combin…
The elastic backward proton-deuteron scattering is analyzed including both relativistic effects in the deuteron and the reaction mechanism. It is shown that inclusion of the graphs corresponding to the emission, rescattering and absorption of the virtual pion by a deuteron nucleon in addition to the one-nucleon exchange graph allows a rather satisfactory description of all the experimental data on the differential cross section, tensor analyzing power of the deuteron and transfer polarization in this reaction.
The so called "barrier distribution" derived from quasi-elastic backscattering of heavy ions gives us, in fact, an information about the "reaction threshold distribution". For light nuclear systems these distributions are quite close, but for heavy ones (when interaction of nuclei becomes more and more complicated and the potential barrier can disappear at all) they may significantly differ. The same should hold also for weakly bound neutron rich projectiles, for which the neutron transfer and break-up reaction channels play an important role at near-barrier energies. This is not a terminology…
It is shown that the shoulder observed in the cross section of $p^3He$ backward elastic scattering at proton beam energies of 0.4 -- 0.7 GeV can be explained by the mechanism of virtual $π$-meson production with a dominant contribution from the subprocesses $pd^*\to ^3$He$ π^0$ and $p(pp)\to^3$He$ π^+$, where $d^*$ denotes the singlet deuteron and the $pp$ pair is in the $^1S_0$ state. At high energies, 1-3 GeV, the mechanism of $np$-pair transfer dominates and probes high-momentum $NN(^1S_0$) correlations in $^3$He.
The two-body transfer amplitude for the rearrangement process i+(jkl) - j+(ikl) is constructed on the basis of technique of 4-dimensional covariant nonrelativistic graphs. The developed formalism is applied to describing backward elastic $p^3He$ scattering in the energy range 0.5 - 1.7 GeV. Numerical calculations performed using the 5- channel wave function of the $^3He$ nucleus show that the transfer of a noninteracting np- pair dominates and explains satisfactorily the energy and angular dependence of the differential cross section at energies 0.9 - 1.7$ GeV. A weak sensitivity to high momen…
The elastic backward proton-deuteron scattering is analyzed within a fully covariant approach based on the invariant expansion of the reaction amplitude. The method of calculation of any observables for any reaction mechanism is developed. The cross section and spin observables, like tensor analyzing power and polarization transfer coefficient etc., are investigated in explicit form within framework of the impulse approximation using different kinds of the relativistic deuteron wave function (DWF) with P-wave components. Our results of numerical calculation for complete set of polarization obs…
We provide systematic analysis of the differential cross section of the proton-$^3{\rm He}$ elastic scattering at $θ_{\rm cm}=180^{\circ}$ and at $T_p<700$ MeV. Three mechanisms are discussed: 2N pair exchange in the triplet and singlet spin states, pion exchange and direct mechanism. It is shown that t Tp>150 MeV tree-body structure, including triplet and singlet states of the 2N pair, becomes of great importance for understanding energy dependence of the reaction observables. Prediction for the differential cross section and the polarization correlation $C_{00nn} which can be studied now in …
The mechanism of $p^3$He backward elastic scattering is studied. It is found that the triangle diagrams with the subprocesses $pd\to ^3$He$ π^0$, $pd^*\to ^3$He$ π^0$ and $p(pp)\to^3$He$ π^+$, where $d^*$ and $pp$ denote the singlet deuteron and diproton pair in the $^1S_0$ state, respectively, dominate in the cross section at 0.3-0.8 GeV, and their contribution is comparable with that for a sequential transfer of a $np$ pair at 1-1.5 GeV. The contribution of the $d^*+pp$, estimated on the basis of the spectator mechanism of the $p(NN)\to ^3$He$ π$ reaction, increases the $p^3$He$\to ^3$He$ p$…
The article is devoted to the relativistic study of elastic $pD$ backward scattering based on the one-nucleon exchange diagram. Calculations were performed using relativistic deuteron wave functions obtained by solving the Bethe-Salpeter equation in the Minkowski space with relativistic separable potentials. The unpolarized differential cross section as well as some polarization observables of the reaction for initial proton momentum up to 7.3 GeV were calculated. The obtained results are compared with the calculations of other authors.
Backward elastic $p ^3He$-scattering at incident proton kinetic energies $T_p>1$ GeV is investigated in the framework of the np-pair transfer mechanism and triangular diagram of one-pion exchange with a subprocess $pd\to ^3Heπ^0$ using a realistic three-body wave function of the $^3He$ nucleus. It is found that the $np-$pair transfer mechanism dominates owing to a rich high momentum component of the $^3He$ wave function. We show that the experimental cross section of this process is defined mainly by the values of the Faddeev component of the $^3He$ wave function, $ϕ^{23}({\bf q}_{23}, {\bf p}…
The deuteron break-up exclusive reaction $p+d \to N(180^{\circ}) + (NN)(0^{\circ})$ is considered in the framework of the one-nucleon-exchange mechanism at the incident proton kinetic energy 0.2--2 GeV and the relative energy of nucleons in the forward going final NN-pair $E_{NN}=0$--20 MeV, that is close to the kinematical conditions of the planned experiment at COSY. The off-energy-shell effects resulting, in particular, in the node of the half-off-shell $^1S_0$-state partial NN-scattering amplitude and the role of higher partial waves in the subprocess $pN\to pN$ are analysed and found to b…
The effects of relativistic kinematics are studied for nuclear collisions of equal mass nuclei. It is found that the relativistic and non-relativistic elastic scattering amplitudes are nearly indistinguishable, and, hence, the relativistic and non-relativistic differential cross sections become indistinguishable. These results are explained by analyzing the Lippmann-Schwinger equation with the first order optical potential that was employed in the calculation
The threshold electrodisintegration of the deuteron at backward angles is studied with a relativistic Hamiltonian, including a relativistic one-pion-exchange potential (OPEP) with off-shell terms as predicted by pseudovector coupling of pions to nucleons. The bound and scattering states are obtained in the center-of-mass frame, and then boosted from it to the Breit frame, where the evaluation of the relevant matrix elements of the electromagnetic current operator is carried out. The latter includes, in addition to one-body, also two-body terms due to pion exchange, as obtained, consistently wi…
Statistical fluctuations in the transverse distribution of sources in relativistic heavy ion collisions and an asymmetric emission profile associated with the wounded nucleons lead to rapidity dependence of the reaction plane. The size of this effect is estimated for the gold-gold collisions at the highest RHIC energy ($\sqrt{s_{NN}}=200 \mathrm{GeV}$) in the Glauber model using GLISSANDO. The hydrodynamical evolution of the resulting torqued fireball is carried out in 3+1 dimensions considering a perfect fluid. Hadronization is simulated using THERMINATOR including non-flow contribution comin…
A relativistic distorted-wave impulse-approximation model is applied to neutral-current and charged-current quasi-elastic neutrino-nucleus scattering. The effects of final state interactions are investigated and the sensitivity of the results to the strange nucleon form factors is discussed in view of their possible experimental determination
We solved the three-nucleon Faddeev equation including relativistic features such as relativistic kinematics, boost effects and Wigner spin rotations. As dynamical input a relativistic nucleon-nucleon interaction exactly on-shell equivalent to the AV18 potential has been used. The effects of Wigner rotations for elastic scattering observables were found to be small. The boost effects are significant at higher energies.They diminish the transition matrix elements at higher energies and lead in spite of the increased relativistic phase-space factor as compared to the nonrelativistic one to rathe…
For backward elastic scattering of deuterons by ^3He, cross sections σand tensor analyzing power T_{20} are measured at E_d=140-270 MeV. The data are analyzed by the PWIA and by the general formula which includes virtual excitations of other channels, with the assumption of the proton transfer from ^3He to the deuteron. Using ^3He wave functions calculated by the Faddeev equation, the PWIA describes global features of the experimental data, while the virtual excitation effects are important for quantitative fits to the T_{20} data. Theoretical predictions on T_{20}, K_y^y (polarization transfe…
Elastic $^{16}$O+$^{12}$C scattering is known to exhibit the nuclear rainbow pattern at incident energies $E_\text{lab}\gtrsim 200$ MeV, with the Airy structure of the far-side scattering cross section clearly seen at medium and large angles. Such a rainbow pattern is well described by the deep real optical potential (OP) given by the double-folding model (DFM). At lower energies, the extensive elastic $^{16}$O+$^{12}$C scattering data show consistently that the nuclear rainbow pattern at backward angles is deteriorated by an oscillating enhancement of elastic cross section that is difficult t…
Parity violating elastic electron scattering on neutron-rich nuclei is described in the framework of relativistic mean-field theory. Self-consistent ground state density distributions of Ne, Na, Ni and Sn isotopes are calculated with the relativistic Hartree- Bogoliubov model, and the resulting neutron radii are compared with available experimental data. For the elastic scattering of 850 MeV electrons on these nuclei, the parity-violating asymmetry parameters are calculated using a relativistic optical model with inclusion of Coulomb distortion effects. The asymmetry parameters for chains of i…
We use the ultra-relativistic quantum molecular dynamic UrQMD version 2.2 to study forward backward fluctuations and compare our results with the published data by the PHOBOS.
We present quasi-elastic neutrino-nucleus cross sections in the energy range from 150 MeV up to 5 GeV for the target nuclei 12C and 56Fe. A relativistic description of the nuclear dynamics and the neutrino-nucleus coupling is adopted. For the treatment of final-state interactions (FSI) we rely on two frameworks succesfully applied to exclusive electron-nucleus scattering: a relativistic optical potential and a relativistic multiple-scattering Glauber approximation. At lower energies, the optical-potential approach is considered to be the optimum choice, whereas at high energies a Glauber appro…
We analyze the multiplicity correlations between distant forward and backward rapidity regions in relativistic heavy-ion collisions in a superposition framework, where the particle production occurs through independent emission from correlated sources. This in principle allows for inferring information on the long-range forward-backward correlations of the sources in the earliest phase of the collision, based solely on the experimental information on the statistical features of the observed particle distributions. Our three-stage study incorporates the fluctuations of parton production in the …
We analyze the elastic scattering of protons on a 4n system. This was used as part of the detection technique of a recent experiment [1] to search for the 4n (tetraneutron) as a bound particle. We show that it is unlikely that this process alone could yield the events reported in ref. [1], unless the 4n has an anomalously large backward elastic scattering amplitude.
A detailed study of two-photon exchange in unpolarized and polarized elastic electron--nucleon scattering is presented, taking particular account of nucleon finite size effects. Contributions from nucleon elastic intermediate states are found to have a strong angular dependence, which leads to a partial resolution of the discrepancy between the Rosenbluth and polarization transfer measurements of the proton electric to magnetic form factor ratio, G_E/G_M. The two-photon exchange contribution to the longitudinal polarization transfer P_L is small, whereas the contribution to the transverse pola…
A new non-relativistic expansion in terms of the nucleon's momentum inside nuclear matter of the current for isobar electro-excitation from the nucleon is performed. Being exact with respect to the transferred energy and momentum, this yields new current operators which retain important aspects of relativity not taken into account in the traditional non-relativistic reductions. The transition current thus obtained differs from the leading order of the traditional expansion by simple multiplicative factors. These depend on the momentum and energy transfer and can be easily included together wit…
We present the first study to examine the validity of the relativistic impulse approximation (RIA) for describing elastic proton-nucleus scattering at incident laboratory kinetic energies lower than 200 MeV. For simplicity we choose a $^{208}$Pb target, which is a spin-saturated spherical nucleus for which reliable nuclear structure models exist. Microscopic scalar and vector optical potentials are generated by folding invariant scalar and vector scattering nucleon-nucleon (NN) amplitudes, based on our recently developed relativistic meson-exchange model, with Lorentz scalar and vector densiti…
The influence of relativistic contributions to elastic electron deuteron scattering is studied systematically at low and intermediate momentum transfers ($Q^2\leq 30$ fm$^{-2}$). In a $(p/M)$-expansion, all leading order relativistic $π$-exchange contributions consistent with the Bonn OBEPQ models are included. In addition, static heavy meson exchange currents including boost terms and lowest order $ρπγ$-currents are considered. Sizeable effects from the various relativistic two-body contributions, mainly from $π$-exchange, have been found in form factors, structure functions and the tensor po…
The experimental angular distributions for 20Ne+16O elastic transfer are reanalyzed using different forms of potential both phenomenological and semi-microscopic. The significant increase in cross sections at backward hemisphere due to the contribution of alphacluster transfer is investigated using the distorted wave Born approximation (DWBA) method. The spectroscopic amplitude (SA) for the configuration 20Ne as consisting of 16O (core) and an alpha-particle orbiting this core at the different concerned energies is extracted. The agreement between the experimental data and theoretical calculat…
We use the Ultra-relativistic Quantum Molecular Dynamic model (UrQMD v2.2) to study forward-backward fluctuations and compare our results with the data published by the PHOBOS experiment. The extracted effective cluster multiplicities show a clear centrality dependence within the present hadron-string transport approach. This behavior is not reproduced with models not taking into account final state rescattering.
We investigate the screening effects on the nucleon-nucleon elastic cross section inside nuclear matter at zero and finite temperature. The N-N interaction is described phenomenologically via meson exchanges ($σ$, $π$ and $ω$) in the framework of a relativistic lagrangian model. The expressions for the in-medium meson propagators, which take into account the effects of matter polarization and renormalized vacuum polarization, are used in the calculation of the various meson contributions to the total cross section in the one-boson exchange approximation. The final expressions allow a satisfact…
In this paper, we provide a procedure to calculate the bremsstrahlung spectrum for virtually any relativistic bare ion with charge 6$e$ or beyond, $Z\ge 6$, in ultraperipheral collisions with target nuclei. We apply the Weizsäcker-Williams method of virtual quanta to model the effect of the distribution of nuclear constituents on the interaction of the ion with the radiation target. This leads to a bremsstrahlung spectrum peaking at $2γ$ times the energy of the giant dipole resonance ($γ$ is the projectile energy in units of its rest energy). A central ingredient in the calculation is the cros…
The relationship between the backward elastic scattering probabilities and reaction cross sections is derived. This is a a very simple and useful method to extract reaction cross sections for heavy ion systems. We compare the results of our method with those using the traditional full elastic scattering angular distributions, for several systems, at energies near and above the Coulomb barrier. From the calculated reaction and capture cross sections using the present method, we derive the cross sections of other mechanisms for nearly spherical systems.
We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasi-elastic scattering on the deuteron, at backward angles (lab scattering angle of 108 degrees) for Q2 = 0.22 GeV^2/c^2 and 0.63 GeV^2/c^2 at beam energies of 362 MeV and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single photon exchange. Results for the proton are consistent with a model calculation which includes inelastic int…
Within a covariant Bethe-Salpeter approach the relativistic complex separable kernel of the neutron-proton interaction for the coupled $^3S_1^+$-$^3D_1^+$ partial-wave state is constructed. The rank-six separable potential elaborated earlier is real-valued, and therefore makes it possible to describe only the elastic part (phase shifts, low-energy parameters, deuteron properties, etc.) of the elastic neutron-proton scattering. The description of the inelasticity parameter comes out of the imaginary part introduced intthe potential. The complex potential parameters are obtained using the availa…
A relativistic distorted-wave impulse-approximation model is applied to quasi-elastic neutrino-nucleus scattering. The bound state is obtained in the framework of the relativistic mean field theory and the final state interaction is taken into account in the scattering state. Results for the charged- and neutral-current neutrino (antineutrino) reactions on $^{12}$C target nucleus are presented and the sensitivity of various quantities to the strange quark content of the nucleon weak current is discussed.
We analyze a generic model where wounded quarks are amended with strings in which both end-point positions fluctuate in spatial rapidity. With the assumption that the strings emit particles independently of one another and with a uniform distribution in rapidity, we are able to analyze the model semi-analytically, which allows for its detailed understanding. Using as a constraint the one-body string emission functions obtained from the experimental data for collisions at $\sqrt{s_{NN}}=200$ GeV, we explore the two-body correlations for various scenarios of string fluctuations. We find that the…
We discuss the torque effect in the initial fireball formed in relativistic heavy-ion collisions, manifesting itself, on the event-by-event basis, in a relative angle between the principal axes of the transverse momentum distributions in the forward and backward rapidity regions. The torque follows from two natural features: 1) the sources of particles (e.g. wounded nucleons) emit predominantly in their forward hemispheres, and 2) there exist fluctuations in the transverse distribution of sources from the two colliding nuclei. On the average, the standard event-by-event deviation of the relati…
Due to integrability, baryon-baryon scattering in the massless Gross-Neveu model at large N features only forward elastic scattering. A bare mass term breaks integrability and is therefore expected to induce backward elastic scattering as well as inelastic reactions. We confirm these expectations by a study of baryon-baryon scattering in the massive Gross-Neveu model near the non-relativistic limit. This restriction enables us to solve the time-dependent Hartree-Fock equations with controlled approximations, using a combination of analytical methods from an effective field theory and the numer…
We study in detail the barrier distributions extracted from large-angle quasi-elastic scattering of heavy ions at energies near the Coulomb barrier. Using a closed-form expression for scattering from a single barrier, we compare the quasi-elastic barrier distribution with the corresponding test function for fusion. We examine the isocentrifugal approximation in coupled-channels calculations of quasi-elastic scattering and find that for backward angles, it works well, justifying the concept of a barrier distribution for scattering processes. This method offers an interesting tool for investigat…
Relativistic corrections to the reaction kinematic parameters were made for elastic scattering of \nuc{6}{Li}, \nuc{12}{C} and \nuc{40}{Ar} from \nuc{40}{Ca}, \nuc{90}{Zr}, and \nuc{208}{Pb} targets at incident energies between 20 and 100 MeV/nucleon. Results of optical model calculations show that the effects of such corrections are important in describing the angular distributions of elastic scattering cross sections for heavy ion scattering at incident energies as low as around 40 MeV/nucleon. The effects on the total reaction cross sections on the other hand, were found to be small within …
A microscopic study of proton elastic scattering from unstable nuclei at intermediate energies using a relativistic formalism is presented. We have employed both the original relativistic impulse approximation (IA1) and the generalised impulse approximation (IA2) formalisms to calculate the relativistic optical potentials, with target densities derived from relativistic mean field (RMF) theory using the NL3 and FSUGold parameter sets. Comparisons between the optical potentials computed using both IA1 and IA2 formalisms, and the different RMF Lagrangians are presented for both stable and unstab…
Within a quasipotential framework a relativistic analysis is presented of the deuteron current. Assuming that the singularities from the nucleon propagators are important, a so-called equal time approximation of the current is constructed. This is applied to both elastic and inelastic electron scattering. As dynamical model the relativistic one boson exchange model is used. Reasonable agreement is found with a previous relativistic calculation of the elastic electromagnetic form factors of the deuteron. For the unpolarized inelastic electron scattering effects of final state interactions and r…
Two relativistic approaches to charged-current quasielastic neutrino-nucleus scattering are illustrated and compared: one is phenomenological and based on the superscaling behavior of electron scattering data and the other relies on the microscopic description of nuclear dynamics in relativistic mean field theory. The role of meson exchange currents in the two-particle two-hole sector is explored. The predictions of the models for differential and total cross sections are presented and compared with the MiniBooNE data.
We study the effects of double octupole and quadrupole phonon excitations in the 144Sm nucleus on quasi-elastic 16O+144Sm scattering at backward angles. To this end, we use the coupled-channels framework, taking into account explicitly the anharmonicities of the vibrations. We use the same coupling scheme as that previously employed to explain the experimental data of sub-barrier fusion cross sections for the same system. We show that the experimental data for the quasi-elastic cross sections are well reproduced in this way, although the quasi-elastic barrier distribution has a distinct high e…
Point-form relativistic quantum mechanics is applied to elastic electron-deuteron scattering. The deuteron is modeled using relativistic interactions that are scattering-equivalent to the nonrelativistic Argonne $v_{18}$ and Reid '93 interactions. A point-form spectator approximation (PFSA) is introduced to define a conserved covariant current in terms of single-nucleon form factors. The PFSA is shown to provide an accurate description of data up to momentum transfers of 0.5 ${\rm GeV}^2$, but falls below the data at higher momentum transfers. Results are sensitive to the nucleon form factor p…
The optical potential is a powerful instrument for calculations on a wide variety of nuclear reactions, in particular, for quasi-elastic lepton-nucleus scattering. Phenomenological optical potentials are successful in the description of data but may produce uncertainties in the interpretation of the results. Two recent theoretical optical potentials are presented: a global relativistic folding optical potential, that has been employed in relativistic models for quasi-elastic lepton-nucleus scattering, and a non relativistic optical potential derived from nucleon-nucleon chiral potentials at fo…
The electroweak response functions for inclusive electron scattering are calculated in the Relativistic Fermi Gas model, both in the quasi-elastic and in the $Δ$ peak regions. The impact of relativistic kinematics at high momentum transfer is investigated through an expansion in the initial nucleonic momentum, which is however exact in the four-momentum of the exchanged boson. The same expansion is applied to the meson exchange currents in the particle-hole sector: it is shown that the non-relativistic currents can be corrected by simple kinematical factors to account for relativity. The left-…
The quasipotential formalism for elastic scattering from relativistic bound states is formulated based on the instant constraint in the Breit frame. The quasipotential electromagnetic current is derived from Mandelstam's five-point kernel and obeys a two-body Ward identity. Breit-frame wave functions are obtained directly by solving integral equations with nonzero total three-momentum, thus accomplishing a dynamical boost. Calculations of electron-deuteron elastic form factors illustrate the importance of the dynamical boost versus kinematic boosts of the rest frame wave functions.
The effect of the self-energy on the photon-proton elastic scattering is investigated for the backward and the forward directions. The shape of the Thomson scattering at the photon energy $ω\to 0$ is broken by taking into account the self-energy of proton. The electromagnetic polarizabilities $\barα\pm\barβ$ are calculated by the lowest-order perturbative treatment.
A study of the deuteron structure in the framework of relativistic quantum mechanics is presented. Point-form (PF) relativistic quantum mechanics (RQM) is applied to the elastic eD scattering. The deuteron wave function and neutron form factors are fitted to the electromagnetic deuteron form factors. We also compare results obtained by different realistic deuteron wave functions stemming from Nijmegen-I, Nijmegen-II, JISP16, CD-Bonn, Paris, Argonne, Idaho and Moscow (with forbidden states) potentials. It is shown that the electromagnetic deuteron form factors may be described without exchange …
Elastic and radiative heavy quark interactions with light partons are studied with the partonic transport description BAMPS (Boltzmann Approach to MultiParton Scatterings). After calculating the cross section of radiative processes for finite masses in the improved Gunion-Bertsch approximation and verifying this calculation by comparing to the exact result, we study elastic and radiative heavy quark energy loss in a static medium of quarks and gluons. Furthermore, the full 3+1D space-time evolution of gluons, light quarks, and heavy quarks in ultra-relativistic heavy-ion collisions at the BNL …
The change of the transverse spin asymmetry in the scattering of highly-relativistic spin-polarized electrons from nuclei by vacuum polarization effects is calculated within the Uehling approximation. Results are provided for 1 - 100 MeV electrons scattering from 31P, 64Zn, 152Sm, 197Au and 207,208Pb at backward angles.
The elastic and alpha-production channels for the 6He+208Pb reaction are investigated at energies around the Coulomb barrier (E_{lab}=14, 16, 18, 22, and 27 MeV). The effect of the two-neutron transfer channels on the elastic scattering has been studied within the Coupled-Reaction-Channels (CRC) method. We find that the explicit inclusion of these channels allows a simultaneous description of the elastic data and the inclusive alpha cross sections at backward angles. Three-body Continuum-Discretized Coupled-Channels (CDCC) calculations are found to reproduce the elastic data, but not the trans…
