The application of a phenomenological model to inelastic nucleus-nucleus interactions for laboratory momenta below 5 GeV/c per nucleon of the incident nucleus

International Nuclear Information System (INIS)

Grishin, V.G.; Kladnitskaya, E.N.

1985-01-01

A phenomenological model for inelastic nucleus-nucleus interactions at momenta below 5 GeV/c per nucleon is described. Particle interactions inside the interacting nuclei are described by phenomenological models of hadron-nucleus and hadron-nucleon interactions. The Monte-Carlo model provides the kinematic variables for a set of events under study. The comparison of the model inclusive distri-- butions for different particles and nucleus-nucleus interactions agrees well with the experimental data

Studies of the nucleon-nucleus and the nucleon-nucleon interactions using polarized neutron beams

International Nuclear Information System (INIS)

Walter, R.L.; Howell, C.R.; Tornow, W.

1988-01-01

The results o four scattering measurements using beams of polarized neutrons are described. Results for the analyzing power A y (θ) for elastic scattering of neutrons from protons and deuterons are compared to calculations based on the Paris and the Bonn nucleon-nucleon interactions. Deficiencies particularly in the Bonn model are indicated. A nucleon-nucleus potential is derived from σ(θ) and A y (θ) data for n + 28 Si and p + 28 Si and the Coulomb correction terms are derived according to two approaches. A Fourier-Bessel expansion is used to investigate the form factors of the terms of the n + 208 Pb potential which are necessary to describe σ(θ) and A y (θ) data from 6 to 10 MeV. The nature of the spin-orbit term is also presented. (author)

Study of various models of nuclear interaction potentials: nucleon-nucleus and nucleus-nucleus systems

International Nuclear Information System (INIS)

Ngo, H.

1984-01-01

Several models, performed within a mean field theory, are developed for the calculation of nucleon-nucleus interaction potentials. The first part of the thesis deals with the nucleon-nucleus average interaction. It is mainly devoted to the calculation of dynamical corrections to the Hartree-Fock approximation. Two approaches are used: a microscopic model performed in the framework of the nuclear structure approach and a semi-phenomenological one, based on the application of the dispersion relations to the empirical imaginary potential. Both models take into account finite size effects like collectivity or threshold effects which are important at low energy. The Green's function properties are used for both models. The second part of this work is devoted to the interaction potential between two heavy ions. This calculation, which is performed in the framework of the sudden approximation, uses the energy density formalism (Thomas-Fermi approximation). It has been extended to finite temperature. At T=0 the experimental fusion barriers of heavy systems are reproduced within 4%. Their temperature dependence is studied. The proximity scaling is checked and a universal function is obtained at T=0 and at finite temperature. It is found that the proximity theorem is well satisfied on the average. The dispersion around the mean behaviour increases with increasing temperature. At last, P+A* and α+A* interaction potentials are calculated within a double folding model using a schematic effective interaction [fr

Single nucleon emission in relativistic nucleus-nucleus reactions

International Nuclear Information System (INIS)

Anon.

1992-01-01

Significant discrepancies between theory and experiment have previously been noted for nucleon emission via electromagnetic processes in relativistic nucleus-nucleus collisions. The present work investigates the hypothesis that these discrepancies have arisen due to uncertainties about how to deduce the experimental electromagnetic cross section from the total measured cross section. An optical-model calculation of single neutron removal is added to electromagnetic cross sections and compared to the total experimental cross sections. Good agreement is found thereby resolving some of the earlier noted discrepancies. A detailed comparison to the recent work of Benesh, Cook, and Vary is made for both the impact parameter and the nuclear cross section. Good agreement is obtained giving an independent confirmation of the parameterized formulas developed by those authors

Microscopic theory for nucleon-nucleus optical potential in intermediate energies

International Nuclear Information System (INIS)

He Guozhu; Cai Chonghai

1984-01-01

Based on the scattering theory of KMT and FGH we calculate the nucleon-nucleus optical potentials of 4 He, 16 O and 40 Ca from the Paris N-N potential given by M. Lacombe et al. The real part Vsub(R)(r) of our optential has the form of Woods-Saxon when the kinetic energy E of the incident nucleon is low. The depth of Vsub(R)(r) will decrease as E increases, and it turns into positive in the interior of nucleus when E approx.= 300 MeV. The repulsive effect in the interior of nucleus increases rapidly as E increases even more, butthere always exists some attractive effect at the surface of nucleus. Therefore, Vsub(R)(r) has generally the wine-bottle bottom shape. We also calculate the quatity Jv/N = (4π/N)∫sub(0)sub(infinity)Vsub(R)(r)r 2 dr. Our results are basically in acordance with those of M.Jaminon et al's relativistic Hatree calculation as well as the experimental results. In this work we also calculate the imaginary part of optical potential and its variation with the kinetic energy of the incident nucleon

Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies: Final report

International Nuclear Information System (INIS)

Burleson, G.R.

1987-01-01

We are applying for a three-year grant from the US Department of Energy to New Mexico State University to continue its support of our work on experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies, which has been carried out in collaboration with groups from various laboratories and universities. The nucleon-nucleon work is aimed at making measurements that will contribute to a determination of the isospin-zero amplitudes, as well as continuing our investigations of evidence for dibaryon resonances. It is based at the LAMPF accelerator in Los Alamos, New Mexico. Current and planned experiments include measurements of total cross-section differences in pure spin states and of spin parameters in neutron-proton scattering. The pion-nucleus work is aimed at improving our understanding both of the nature of the pion-nucleus interaction and of nuclear structure. It consists of two programs, one based at LAMPF and one based principally at the SIN laboratory in Switzerland. The LAMPF-based work involves studies of large-angle scattering, double-charge-exchange scattering, including measurements at a new energy range above 300 MeV, and a new program of experiments with polarized nuclear targets. The SIN-based work involves studies of quasielastic scattering and absorption, including experiments with a new large-acceptance detector system planned for construction there. We are requesting support to continue the LAMPF-based work at its current level and to expand the SIN-based work to allow for increased involvement in experiments with the new detector system. 57 refs

Hard breakup of two nucleons from the 3He nucleus

International Nuclear Information System (INIS)

Sargsian, Misak M.; Granados, Carlos

2009-01-01

We investigate a large angle photodisintegration of two nucleons from the 3 He nucleus within the framework of the hard rescattering model (HRM). In the HRM a quark of one nucleon knocked out by an incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with large relative momentum. Assuming the dominance of the quark-interchange mechanism in a hard nucleon-nucleon scattering, the HRM allows the expression of the amplitude of a two-nucleon breakup reaction through the convolution of photon-quark scattering, NN hard scattering amplitude, and nuclear spectral function, which can be calculated using a nonrelativistic 3 He wave function. The photon-quark scattering amplitude can be explicitly calculated in the high energy regime, whereas for NN scattering one uses the fit of the available experimental data. The HRM predicts several specific features for the hard breakup reaction. First, the cross section will approximately scale as s -11 . Second, the s 11 weighted cross section will have the shape of energy dependence similar to that of s 10 weighted NN elastic scattering cross section. Also one predicts an enhancement of the pp breakup relative to the pn breakup cross section as compared to the results from low energy kinematics. Another result is the prediction of different spectator momentum dependencies of pp and pn breakup cross sections. This is due to the fact that the same-helicity pp-component is strongly suppressed in the ground state wave function of 3 He. Because of this suppression the HRM predicts significantly different asymmetries for the cross section of polarization transfer NN breakup reactions for circularly polarized photons. For the pp breakup this asymmetry is predicted to be zero while for the pn it is close to (2/3).

Hadron-nucleus collisions

International Nuclear Information System (INIS)

Strugalski, Z.

1981-01-01

Qualitative picture of high energy hadron-nucleus collision process, emerging from the analysis of experimental data, is presented. Appropriate description procedure giving a possibility of reproducing various characteristics of this process in terms of the data on elementary hadron-nucleon interaction is proposed. Formula reproducing hadron-nucleus collision cross sections is derived. Inelastic collision cross sections for pion-nucleus and proton-nucleus reactions at wide energy interval are calculated for Pb, Ag, and Al targets. A-dependence of cross sections for pion-nucleus and proton-nucleus collisions at nearly 50 GeV/c momentum were calculated and compared with existing experimental data. Energy dependence of cross sections for hadron-nucleus collisions is determined simply by energy dependence of corresponding cross sections for hadron-nucleon collisions; A-dependence is determined simply by nuclear sizes and nucleon density distributions in nuclei

The nucleon-nucleus scattering at intermediate energies

International Nuclear Information System (INIS)

Auger, J.-P.

1976-01-01

The Glauber model has the merit to connect directly the nucleon-nucleus elastic differential cross section with the nucleon-nucleon amplitude and nuclear densities. The general agreement between the 1 GeV proton elastic scattering differential cross sections calculated without adjustable parameter and the experimental data (from He 4 to Pb 208 ) is rather satisfactory up to 2. - 2.5 fm -1 momentum transfer. Although the 1 GeV proton elastic scattering experiments constitute at present one of the best method in determining neutron densities, it seems that self-consistent calculations bring the best knowledge of these densities. The model independent analysis performed with electron and proton scattering experiments show that the difference between neutron and proton r.m.s. radius cannot be determined better than 25-30% for Pb 208 [fr

From Nucleons to Nucleus Concepts of Microscopic Nuclear Theory

CERN Document Server

Suhonen, Jouni

2007-01-01

From Nucleons to Nucleus deals with single-particle and collective features of spherical nuclei. Each nuclear model is introduced and derived in detail. The formalism is then applied to light and medium-heavy nuclei in worked-out examples, and finally the acquired skills are strengthened by a wide selection of exercises, many relating the models to experimental data. Nuclear properties are discussed using particles, holes and quasiparticles. A large number of matrix elements of standard operators have been tabulated for reference. From Nucleons to Nucleus is based on lectures on nuclear physics given by the author. Its main scope is thus to serve as a textbook for advanced students. But also researchers will appreciate it as wellbalanced reference to theoretical nuclear physics.

New aspects in nucleon-nucleus collisions and EAS properties around 10(6) GeV

International Nuclear Information System (INIS)

Capdevielle, J.N.; Gawin, J.

1985-01-01

At energies higher than 2 x 10 to the 5 GeV, very little information exists on detailed properties of nucleon-nucleon collision; the rare elements are coming from jets and as nondirect improvements from gamma-ray families. The results exhibit some conflicting features, or at least, very large fluctuations like copious production of gamma rays in opposition to Centauro-like events, which suggest that phase transition to quark-gluon plasma occurs in nucleus-nucleus collisions and even in nucleon-nucleus collision. The multicluster phenomenological model (MPM) is extrapolated for EAS simulation up to 5 x 10 to the 6 GeV to put in evidence some significant deviation between experimental data and prediction

Description of nuclear structure and cross sections for nucleon-nucleus scattering on the basis of effective Skyrme forces

International Nuclear Information System (INIS)

Kuprikov, V. I.; Pilipenko, V. V.; Soznik, A. P.; Tarasov, V. N.; Shlyakhov, N. A.

2009-01-01

The possibility of constructing such new versions of effective nucleon-nucleon forces that would make it possible to describe simultaneously the cross sections for nucleon-nucleus scattering and quantities characterizing nuclear matter and the structure of finite even-even nuclei is investigated on the basis of a microscopic nucleon-nucleus optical potential that is calculated by using effective Skyrme interaction. A procedure for optimizing the parameters of Skyrme forces by employing fits to specific angular distributions for neutron-nucleus scattering and by simultaneously testing the features of nuclear matter, the binding energy of the target nucleus, and its proton root-mean-square radius is proposed. A number of versions of modified Skyrme forces that ensure a reasonable description of both nucleon-nucleus scattering and the properties of nuclear structure are found on the basis of this procedure.

Simulated nucleon–nucleon and nucleon–nucleus reactions in the ...

Indian Academy of Sciences (India)

In this study, we have used quantum molecular dynamic (QMD) as a theoretical model to ... Nuclear reactions; quantum dynamics; cascade exciton model. ... particle incident on a nucleus will interact with individual nucleons, with the final ...

Nucleus-nucleus interaction constants at energies of 0.1-1.0 GeV/nucleon

International Nuclear Information System (INIS)

Dudkin, V.E.; P'yanov, I.I.; Stepnov, V.D.

1979-01-01

A method for calculating nucleus-nuclear reactions being a further development of the cascade model is proposed. The nucleus-nucleus interaction is represented as a superposition of a series of synchronous cascades initiated by nucleous and α-clusters getting into the nuclei overlapping region. Determination of an interaction partner and calculation of an elementary nucleon and α-cluster collision act are carried out using the same method as for calculation of the nucleon-nuclear cascade. Inelastic channels are not considered. The cross section values of cascade particle interaction, as well as of free particle interaction are given from the published literature. The experiment for verification of the calculation method is carried out. An emulsion chamber of the 0.3 l volume has been exposed at the 35 km height in the vicinity of the 64 deg nothern latitude during 8.5 hr. 223 disintegrations of nuclear emulsion by cosmic radiation nuclei at the 0.1-1.0 GeV/nucleon energy and the >2 charge are investigated. 147 interactions on photoemulsion light nuclei are singled out from these disintegrations. The average multiplicity of all the charged pions is 0.22+-0.05 for light and 0.44+-0.09 for heavy photoemulsion nuclei. The calculation is carried out for nitrogen nuclei interaction at the 0.35 GeV/nucleon energy. Parametric analysis of the calculation method has shown that the clusterization coefficients and the nuclear parameter effect secondary particle multiplicity (SPM) and weakly influence on their energy and angular distributions. The nuclear parameter change from 1.1 to 1.6 F decreases average SPM in different energy ranges down to 25-40%. The comparison of the calculation data with the experimental one obtained in the given paper and other ones, shows satisfactory agreement both for differential and average characteristics of secondary charged particles

Hadron-nucleus interactions in the nucleon resonance region

Energy Technology Data Exchange (ETDEWEB)

Gessler, Stefanie

2017-06-15

Experiments with high-energy hadron beams have found renewed attention. In the near future nuclear studies with hadron beams are planned at least at two facilities, namely J-PARC in Japan and GSI/FAIR. The aim of this work is an exploratory investigation of interactions of mesons and baryons with nuclei at energies of interest for future research with antiprotons at FAIR. The theoretical discussion is started with an introductory presentation of the optical model and Eikonal theory as appropriate tools for the description of scattering processes at high energies. In antiproton interactions with nucleons and nuclei, annihilation processes into pions are playing the major role for the reaction dynamics. Therefore, we consider first the interactions of pions with nuclei by deriving an extended selfenergy scheme for a large range of incident pion energies. In order to have a uniform description over a broad energy interval, the existing approaches had to be reconsidered and in essential parts reformulated and extended. A central result is the treatment of pion-nucleus self-energies from high lying N{sup *} resonances. Only by including those channels in a proper manner into the extended pion optical potential, pion-nucleus scattering could be described over the required large energy range. At low energies the well known Kisslinger potential is recapped. Next, the same type of reaction theory is used to analyze antiproton-nucleon and nucleus scattering from low to highly relativistic energies. The reaction dynamics of antiproton interactions with nuclear targets is discussed. We start with a new approach to antiproton-nucleon scattering. A free-space antiproton-nucleon T-matrix is derived, covering an energy range as wide as from 100 MeV up to 15 GeV. Eikonal theory is used to describe the antiproton scattering amplitudes in momentum and in coordinate space. We consider, in particular, interactions with nuclei at energies around and well above 1 GeV. The antiproton-nucleus

Hadron-nucleus interactions in the nucleon resonance region

International Nuclear Information System (INIS)

Gessler, Stefanie

2017-06-01

Experiments with high-energy hadron beams have found renewed attention. In the near future nuclear studies with hadron beams are planned at least at two facilities, namely J-PARC in Japan and GSI/FAIR. The aim of this work is an exploratory investigation of interactions of mesons and baryons with nuclei at energies of interest for future research with antiprotons at FAIR. The theoretical discussion is started with an introductory presentation of the optical model and Eikonal theory as appropriate tools for the description of scattering processes at high energies. In antiproton interactions with nucleons and nuclei, annihilation processes into pions are playing the major role for the reaction dynamics. Therefore, we consider first the interactions of pions with nuclei by deriving an extended selfenergy scheme for a large range of incident pion energies. In order to have a uniform description over a broad energy interval, the existing approaches had to be reconsidered and in essential parts reformulated and extended. A central result is the treatment of pion-nucleus self-energies from high lying N * resonances. Only by including those channels in a proper manner into the extended pion optical potential, pion-nucleus scattering could be described over the required large energy range. At low energies the well known Kisslinger potential is recapped. Next, the same type of reaction theory is used to analyze antiproton-nucleon and nucleus scattering from low to highly relativistic energies. The reaction dynamics of antiproton interactions with nuclear targets is discussed. We start with a new approach to antiproton-nucleon scattering. A free-space antiproton-nucleon T-matrix is derived, covering an energy range as wide as from 100 MeV up to 15 GeV. Eikonal theory is used to describe the antiproton scattering amplitudes in momentum and in coordinate space. We consider, in particular, interactions with nuclei at energies around and well above 1 GeV. The antiproton-nucleus

Particle correlations in proton-nucleus and nucleus-nucleus collisions

International Nuclear Information System (INIS)

Nagamiya, Sh.

1981-01-01

Particle correlations in proton-nucleus and nucleus-nucleus collisions at energies of 1-2 GeV/nucleon are investigated. The problems of measurement of the mean free path lambda of protons inside the nucleus and the interaction radius of nucleus-nucleus collisions is considered. The value of lambda has been determined in two-proton coincidence experiment in proton-nucleus interaction at 800 MeV. The observed value of lambda is slightly longer than the expected from free nucleon-nucleon collisions. Some preliminary results on proton emission beyond free nucleon-nucleon kinemaics are given

Weak and strong factorization properties in nucleus-nucleus collisions in the energy region 290-2100 MeV/nucleon

International Nuclear Information System (INIS)

La Tessa, C. . E-mail chiara@nephy.chalmers.se; Sihver, L.; Mancusi, D.; Zeitlin, C.; Miller, J.; Guetersloh, S.; Heilbronn, L.

2007-01-01

We have collected from the literature partial charge-changing cross sections for projectiles with charge 6=< Z=<26, energy ranging from 290 up to 2100 MeV/nucleon and interacting with several targets, in order to investigate weak and strong factorization properties. The same analysis methods as in our previous work have been applied to the data: we have shown that, except for hydrogen targets, weak and strong factorization properties are valid within 5%, thus confirming the results obtained in the first paper [C. La Tessa, et al., Test of weak and strong factorization in nucleus-nucleus collisions at several hundred MeV/nucleon, Nucl. Phys. A, in press]. Factorization parameters have been calculated and, in particular, target factors have been expressed with ad hoc analytical functions which describe the data trend very well. New expressions for weak and strong factorization properties can then be obtained by substituting the target factors with these functions: this formulation partially isolates the dependence of the partial charge-changing cross sections on the target and projectile mass numbers; moreover, fragment factors are the only parameters left in the formulas thus facilitating the future task of interpolating them with appropriate analytical expressions

Radial Dependence of the Nucleon Effective Mass in B sup 1 sup 0

CERN Document Server

Bever, L J D; Hicks, R; Jager, K D; Kelly, J; Lapikas, L; Miskimen, R; Neck, D V; Peterson, G; Steenhoven, G; Vries, H D

1998-01-01

The dynamic properties of the atomic nucleus depend strongly on correlations between the nucleons. We present a combined analysis of inelastic electron-scattering data and electron-induced proton knockout measurements in an effort to obtain phenomenological information on nucleon-nucleon correlations. Our results indicate that the ration of radial wave functions extracted from precise B sup 1 sup 0 (e,e') and B sup 1 sup 0 (e, e'p) measurements evolve from an interior depression for small Em, characteristic of short-range correlations, to a surface-peaked enhancement for larger Em, characteristic of long-range correlations. This observation can be interpreted in terms of the nucleon effective mass.

Three-body approach to the nucleon-nucleus optical potential

International Nuclear Information System (INIS)

Tandy, P.C.; Redish, E.F.; Bolle, D.

1976-01-01

In the Watson single scattering theory of the optical potential it is customary to approximate the propagation by two-body Green functions in order to simplify calculations. The reaction mechanism being described, however, is decidedly three-body in character. The central difficulty in building three-body models for nucleon-nucleus elastic scattering is to find the proper way of imbedding the superposed three-body reaction mechanism in the many-body problem without introducing serious overcounting effects. One would also like an explicit description of the intermediate state processes responsible for absorption. In this paper a three-body approximation to the optical potential theory is presented which overcomes the overcounting problem and is capable of including the following effects: (1) the proper kinematics of the struck nucleon, (2) its binding potential, (3) the identity of target nucleons, and (4) realistic wave functions and spectroscopic factors. The three-body model for the optical potential can be extended using unitarity methods to yield a unified three-body-like model of elastic scattering, pickup, and single nucleon knockout. (Auth.)

Charge Dependence and Electric Quadrupole Effects on Single-Nucleon Removal in Relativistic and Intermediate Energy Nuclear Collisions

Science.gov (United States)

Norbury, John W.

1992-01-01

Single nucleon removal in relativistic and intermediate energy nucleus-nucleus collisions is studied using a generalization of Weizsacker-Williams theory that treats each electromagnetic multipole separately. Calculations are presented for electric dipole and quadrupole excitations and incorporate a realistic minimum impact parameter, Coulomb recoil corrections, and the uncertainties in the input photonuclear data. Discrepancies are discussed. The maximum quadrupole effect to be observed in future experiments is estimated and also an analysis of the charge dependence of the electromagnetic cross sections down to energies as low as 100 MeV/nucleon is made.

Global variables and the dynamics or relativistic nucleus-nucleus collisions

International Nuclear Information System (INIS)

Cugnon, J.; L'Hote, D.

1983-01-01

Various global variables providing a simple description of high multiplicity events are reviewed. Many of them are calculated in the framework of an intra-nuclear cascade model, which describes the collision process as a series of binary on-shell relativistic baryon-baryon collisions and which includes inelasticity through the production of δ-resonances. The calculations are first made for the Ar+KCl system at 0.8 GeV/A, with global variables including either all the nucleons or only the participant nucleons. The shape and the orientation of the ellipsoid of sphericity are particularly investigated. For both cases, on the average, the large axis of the ellipsoid is found to point in the beam direction. This result is discussed in comparison with hydrodynamics predictions and in relation with the mean free path. A kind of small 'bounce-off effect' is detected for intermediate impact parameters. The possibility of extracting the value of the impact parameter b from the value of a global variable is shown to depend upon the variation of this variable with b and upon the fluctuation of the global variable for a given impact parameter. A quality factor is defined to quantify this possibility. No current global variable seems to be more appropriate than the number of participant nucleons for the impact parameter selection. The physical origin of the fluctuations inside the intranuclear cascade model is discussed and the possibility of extracting useful information on the dynamics of the system from the fluctuations is pointed out. The energy dependence of our results is discussed. Some results of the calculations at 250 and 400 MeV/A are also presented for the same system Ar+KCl. (orig.)

Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies: Annual progress report, 1988--1989

International Nuclear Information System (INIS)

1988-01-01

This report summarizes the work on experimental research in intermediate energy nuclear and particle physics carried out by New Mexico State University in 1988 under a grant from the US Department of Energy. The nucleon-nucleon research has involved studies of interactions between polarized neutrons and polarized protons. Its purpose is to help complete the determination of the nucleon-nucleon amplitudes at energies up to 800 MeV, as part of a program currently in progress at LAMPF, as well as to investigate the possibility of the existence of dibaryon resonances. The pion-nucleus research involves studies of this interaction in regions where it has not been adequately explored. These include experiments on elastic and double charge exchange scattering at energies above the /Delta/(1232) resonance, interactions with polarized nuclear targets, and investigations of pion absorption using a detector covering nearly the full solid angle region. 21 refs., 4 figs

Global observables in Si + nucleus collisions at 14.6 GeV per nucleon

International Nuclear Information System (INIS)

Shivakumar, B.; Greene, S.V.; Hemmick, T.K.; Majka, R.; Mitchell, J.T.; Rotondo, F.; Sandweiss, J.; Barrette, J.; Mark, S.K.; Pruneau, C.; Bellwied, R.; Braun-Munzinger, P.; David, G.; Herrmann, N.; Ingold, G.; Llope, W.J.; Muthuswamy, M.; Stachel, J.; Waters, L.; Cleland, W.E.; Jayananda, K.; Kraus, D.; Sonnadara, U.; Fatyga, M.; Hogue, R.W.; Lissauer, D.; Ludlam, T.; Makowiecki, D.; O'Brien, E.; Polychronakos, V.; Takai, H.; Throwe, T.; Woody, C.; Fox, D.; Sunier, J.; Van Hecke, H.; Hall, J.; Wolfe, D.; Heifetz, R.; Rawool-Sullivan, M.; Simon, J.; Sullivan, J.P.; Wolf, K.

1990-01-01

A simultaneous determination of the transverse energy produced, and the multiplicity of beam rapidity nucleons surviving nucleus interactions provides an effective way to quantify the extent of stopping achieved therein. The authors have studied collisions between 28 Si projectiles with energies E lab /A = 14.6 GeV and targets of Al, Cu, and Pb. Transverse energy production has been measured calorimetrically in a pseudorapidity interval -0.5 < η < 0.8, and correlated with the multiplicity of beam rapidity protons and neutrons detected in a 0.8 degree cone centered on the beam direction. Theoretical calculations have been performed to describe the data, and demonstrate quantitatively the large amount of nuclear stopping in these collisions. They also indicate the importance of rescattering in the production of transverse energy

Experimental evidence for dual diffractive resonances in nucleon-nucleus scattering

International Nuclear Information System (INIS)

Ion, D.B.; Ion-Mihai, R.

1981-09-01

Experimental data on nucleon-nucleus scattering for laboratory momenta between 0.9:10 GeV/c are analysed in terms of the dual diffractive resonance (DDR) mechanism. The experimental data for all the nuclei are found to agree well with the predictions of the collective DDR states dominance. (authors)

Experimental studies of nucleon-nucleon and pion-nucleus interactions at intermediate energies: Progress report, January 1, 1985-December 31, 1987

International Nuclear Information System (INIS)

1987-01-01

This report summarizes the work on experimental research in intermediate energy nuclear and particle physics carried out by New Mexico State University in 1985-87. These studies have involved investigations of nucleon-nucleon and pion-nucleus interactions. They have been carried out at the LAMPF accelerator at the Los Alamos National Laboratory, at the SIN laboratory near Zurich, Switzerland, and at the TRIUMF accelerator in Vancouver, Canada. 86 refs., 5 figs

Probing of the isospin-dependent mean field and nucleon-nucleon cross section in a medium by nucleon emissions

International Nuclear Information System (INIS)

Liu Jianye; Xing Yongzhong; Guo Wenjun

2003-01-01

We study the isospin effects of the mean field and two-body collision on the nucleon emissions at the intermediate energy heavy-ion collisions by using an isospin-dependent transport theory. The calculated results show that the nucleon emission number N n depends sensitively on the isospin effect of nucleon-nucleon cross section and weakly on the isospin-dependent mean field for neutron-poor system in higher beam energy region. In particular, the correlation between the medium correction of two-body collision and the momentum-dependent interaction enhances the dependence of nucleon emission number N n on the isospin effect of nucleon-nucleon cross section. On the contrary, the ratio of the neutron-proton ratio of the gas phase to the neutron-proton ratio of the liquid phase, i.e., the degree of isospin fractionation [(N/Z) gas ] b /[(N/Z) liq ] b depends sensitively on the isospin-dependent mean field and weakly on the isospin effect of two-body collision for neutron-rich system in the lower beam energy region. In this case, N n and [(N/Z) gas ] b /[(N/Z) liq ] b are the probes for extracting the information about the isospin-dependent nucleon-nucleon cross section in the medium and the isospin-dependent mean field, respectively

Target fragmentation in proton-nucleus and 16O-nucleus reactions at 60 and 200 GeV/nucleon

International Nuclear Information System (INIS)

Schmidt, H.R.; Albrecht, R.; Claesson, G.; Bock, R.; Gutbrod, H.H.; Kolb, B.W.; Lund, I.; Siemiarczuk, T.; Awes, T.C.; Baktash, C.; Ferguson, R.L.; Lee, I.Y.; Obenshain, F.E.; Plasil, F.; Sorensen, S.P.; Young, G.R.; Beckmann, P.; Berger, F.; Dragon, L.; Glasow, R.; Kampert, K.H.; Loehner, H.; Peitzmann, T.; Purschke, M.; Santo, R.; Franz, A.; Kristiansson, P.; Poskanzer, A.M.; Ritter, H.G.; Garpman, S.; Gustafsson, H.A.; Oskarsson, A.; Otterlund, I.; Persson, S.; Stenlund, E.

1988-01-01

Target remnants with Z 16 O-nucleus reactions at 60 and 200 GeV/nucleon were measured in the angular range from 30 0 to 160 0 (-1.7 16 O-induced reactions (≅ 300 MeV/c) than in proton-induced reactions (≅ 130 MeV/c). The baryon rapidity distributions are roughly in agreement with one-fluid hydrodynamical calculations at 60 GeV/nucleon 16 O+Au but are in disagreement at 200 GeV/nucleon, indicating the higher degree of transparency at the higher bombarding energy. Both, the transverse momenta of target spectators and the entropy produced in the target fragmentation region are compared to those attained in head-on collisions of two heavy nuclei at Bevalac energies. They are found to be comparable or do even exceed the values for the participant matter at beam energies of about 1-2 GeV/nucleon. (orig.)

Target fragmentation in proton-nucleus and 16O-nucleus reactions at 60 and 200 GeV/nucleon

International Nuclear Information System (INIS)

Schmidt, H.R.; Albrecht, R.; Claesson, G.; Bock, R.; Gutbrod, H.H.; Kolb, B.W.; Lund, I.; Siemiarczuk, T.; Awes, T.C.; Baktash, C.; Ferguson, R.L.; Lee, I.Y.; Obenshain, F.E.; Plasil, F.; Sorensen, S.P.; Young, G.R.; Beckmann, P.; Berger, F.; Dragon, L.; Glasow, R.; Kampert, K.H.; Loehner, H.; Peitzmann, T.; Purschke, M.; Santo, R.; Franz, A.; Kristiansson, P.; Poskanzer, A.M.; Ritter, H.G.; Garpman, S.; Gustafsson, H.A.; Oskarsson, A.; Otterlund, I.; Persson, S.; Stenlund, E.

1988-01-01

Target remnants with Z 16 O-nucleus reactions at 60 and 200 GeV/nucleon were measured in the angular range from 30 0 to 160 0 (-1.7 16 O-induced reactions (= 300 MeV/c) than in proton-induced reactions (= 130 MeV/c). The baryon rapidity distributions are roughly in agreement with one-fluid hydrodynamical calculations at 60 GeV/nucleon 16 O+Au but are in disagreement at 200 GeV/nucleon, indicating the higher degree of transparency at the higher bombarding energy. Both, the transverse momenta of target spectators and the entropy produced in the target fragmentation region are compared to those attained in head-on collisions of two heavy nuclei at Bevalac energies. They are found to be comparable or do even exceed the values for the participant matter at beam energies of about 1-2 GeV/nucleon. (orig.)

Formation of proton-fragments in hadron-nucleus and nucleus-nucleus collisions at high energies

International Nuclear Information System (INIS)

Bazarov, E.Kh.; Olimov, K.; Petrov, V.I.; Lutpullaev, S.L.

2006-01-01

resonances by the highly bound few nucleon systems. This phenomenon, showing up stronger at relatively small nuclei, is interpreted by the presence of the short time correlations of intranuclear nucleons. The more detailed analysis of 16 Op interactions at 3.25 A GeV/s showed that the structure observed at energy spectrum of protons in the range T ≅ 70-90 MeV in the oxygen rest frame is due to the decay of two-nucleon (deuteron-like) system as a result of its absorption of the slow pion. The universal singularity was found out in the momentum spectrum of protons flying forward in the rest frame of fragmenting nucleus, expressed by an independence of mechanism of formation of these protons (excluding the 'evaporated' protons) from the initial energy and the type of target-nucleus. The shape of the momentum spectrum of protons flying to the forward hemi-sphere in the rest frame of fragmenting nucleus does not depend on degree of nucleus excitation, which characterizes the extent of the intranuclear cascade. The existence of strong correlation between the shape of the momentum spectrum of proton-fragments, especially the slow ones, and the degree of excitation of the fragmenting nucleus was shown. (author)

Experimental determination of the effective nucleon-nucleon interaction for p-nucleus reactions at intermediate energies

International Nuclear Information System (INIS)

McClelland, J.B.; Aas, B.; Azizi, A.

1982-01-01

A complete measurement of the polarization transfer observables has been made for the first time in the (p,p') reaction at intermediate energies. Measurements are reported for the 12 C(p,p') 12 C reaction to the 1 + , T = 0(12.71 MeV) and 1 + , T = 1(15.11 MeV) states at 500 MeV at laboratory scattering angles of 3.5 0 , 5.5 0 , 7.5 0 , and 12.0 0 . Linear combinations of these observables are shown to exhibit a very selective dependence on the isoscalar and isovector spin-dependent components of the nucleon-nucleon interaction. To the extent of the validity of the single collision approximation, these amplitudes are compared directly to the free nucleon-nucleon amplitudes at small momentum transfers

Dimuon enhancement in nucleus-nucleus ultrarelativistic interactions

International Nuclear Information System (INIS)

Bordalo, Paula; Abreu, M.C.; Alessandro, B.; Alexa, C.; Arnaldi, R.; Astruc, J.; Atayan, M.; Baglin, C.; Baldit, A.; Bedjidian, M.; Bellaiche, F.; Beole, S.; Bohrani, A.; Boldea, V.; Bussiere, A.; Capelli, L.; Caponi, V.; Casagrande, L.; Castor, J.; Chambon, T.; Chaurand, B.; Chevrot, I.; Cheynis, B.; Chiavassa, E.; Cicalo, C.; Comets, M.P.; Constans, N.; Constantinescu, S.; Contardo, D.; Cruz, J.; De Falco, A.; De Marco, N.; Dellacasa, G.; Devaux, A.; Dita, S.; Drapier, O.; Ducroux, L.; Espagnon, B.; Fargeix, J.; Ferreira, R.; Filippov, S.N.; Fleuret, F.; Force, P.; Gallio, M.; Gavrilov, Y.K.; Gerschel, C.; Giubellino, P.; Golubeva, M.B.; Gonin, M.; Gorodetzky, P.; Grigorian, A.A.; Grossiord, J.Y.; Guber, F.F.; Guichard, A.; Gulkanyan, H.; Hakobyan, R.; Haroutunian, R.; Idzik, M.; Jouan, D.; Karavitcheva, T.L.; Kluberg, L.; Kossakowski, R.; Kurepin, A.B.; Landau, G.; Le Bornec, Y.; Lourenco, C.; Luquin, L.; Macciotta, P.; Mac Cormick, M.; Mandry, R.; Marzari-Chiesa, A.; Masera, M.; Masoni, A.; Mehrabyan, S.; Monteno, M.; Mourgues, S.; Musso, A.; Ohlsson-Malek, F.; Petiau, P.; Piccotti, A.; Pizzi, J.R.; Prado da Silva, W.L.; Puddu, G.; Quintans, C.; Racca, C.; Ramello, L.; Ramos, S.; Rato-Mendes, P.; Riccati, L.; Romana, A.; Ropotar, I.; Saturnini, P.; Scomparin, E.; Serci, S.; Shahoyan, R.; Silva, S.; Sitta, M.; Soave, C.; Sonderegger, P.; Tarrago, X.; Topilskaya, N.S.; Usai, G.L.; Varela, J.; Vercellin, E.; Villatte, L.

1999-01-01

The study of muon pairs in the mass region 1.5 μμ 2 in 450 GeV/c p-A, 200 GeV/nucleon S-U and 158 GeV/nucleon Pb-Pb collisions is presented. In p-A interactions, the dimuon signal mass spectra are well described by a superposition of Drell-Yan and charmed meson semi-leptonic decay contributions, in agreement with previous experiments when considering a linear A dependence. In nucleus-nucleus reactions, taking only into account these two physical ingredients, a dimuon enhancement both with increasing A·B and centrality is observed

Relativistic Random-Phase Approximation with Density-dependent Meson-nucleon Couplings at Finite Temperature

International Nuclear Information System (INIS)

Niu, Y.; Paar, N.; Vretenar, D.; Meng, J.

2009-01-01

The fully self-consistent relativistic random-phase approximation (RRPA) framework based on effective interactions with a phenomenological density dependence is extended to finite temperatures. The RRPA configuration space is built from the spectrum of single-nucleon states at finite temperature obtained by the temperature dependent relativistic mean field (RMF-T) theory based on effective Lagrangian with density dependent meson-nucleon vertex functions. As an illustration, the dependence of binding energy, radius, entropy and single particle levels on temperature for spherical nucleus 2 08P b is investigated in RMF-T theory. The finite temperature RRPA has been employed in studies of giant monopole and dipole resonances, and the evolution of resonance properties has been studied as a function of temperature. In addition, exotic modes of excitation have been systematically explored at finite temperatures, with an emphasis on the case of pygmy dipole resonances.(author)

Results of searches for the nucleon structure displays in high energy hadron-nucleus collisions

International Nuclear Information System (INIS)

Strugalski, Z.

1984-01-01

Hadron-nucleus collision data at projectile energy from a few GeV up to about eight thousand GeV were analysed in order to find effects in which a nucleon structure manifests itself. It was found that some nucleon structure displays in incident hadron deflection in its passage through atomic nuclei and in multiple production process, at energies above about 2 GeV. The distribution of the deflection angles consists of two components, the mean free path for multiparticle production is about three times larger than the expected one. These effects may be interpreted as caused by a nucleon structure

Nuclear surface diffuseness revealed in nucleon-nucleus diffraction

Science.gov (United States)

Hatakeyama, S.; Horiuchi, W.; Kohama, A.

2018-05-01

The nuclear surface provides useful information on nuclear radius, nuclear structure, as well as properties of nuclear matter. We discuss the relationship between the nuclear surface diffuseness and elastic scattering differential cross section at the first diffraction peak of high-energy nucleon-nucleus scattering as an efficient tool in order to extract the nuclear surface information from limited experimental data involving short-lived unstable nuclei. The high-energy reaction is described by a reliable microscopic reaction theory, the Glauber model. Extending the idea of the black sphere model, we find one-to-one correspondence between the nuclear bulk structure information and proton-nucleus elastic scattering diffraction peak. This implies that we can extract both the nuclear radius and diffuseness simultaneously, using the position of the first diffraction peak and its magnitude of the elastic scattering differential cross section. We confirm the reliability of this approach by using realistic density distributions obtained by a mean-field model.

On the A dependence in the process of dilepton production by high-energy nucleons

International Nuclear Information System (INIS)

Gevorkyan, S.R.; Zhamkochyan, V.M.

1978-01-01

The process of lepton pair production in nucleon-nucleus collisions for high energies is considered. It is shown, that with due regard for the N → π → μ + μ - inelastic transitions the experimentally observed A dependence of the cross section of the NA → μ + μ - X process can be explained in the framework of the multiple scattering theory

Semiclassical calculations of the imaginary part of the nucleon-nucleus optical potential

International Nuclear Information System (INIS)

Hasse, R.W.; Schuck, P.

1984-03-01

We calculate for finite nuclei the imaginary part of the nucleus-nucleon optical potential on and off shell by using the local Fermi gas approximation and a finite range two-body exchange force. Results are compared with those obtained by infinite nuclear matter calculations as well as using the local density or Glauber approximation

Measurement of 19F nucleus interaction at 4 GeV/c per nucleon

International Nuclear Information System (INIS)

Golovin, V.M.; Golutvin, I.A.; Dolya, S.N.

1986-01-01

The cross sections of 19 F nucleus interaction with the nuclei of different elements at 4 GeV/c x nucleon momentum in reactions are measured. In the finite state of these reactions the fragment with charge Z≤8 is formed. The experiment apparatus comprises a transmission detector where the nuclei trajectory at the target input has been measured with proportional chambers whereas the nuclear charge before and after the target has been measured by Cherenkov counters. Experimental data obtained with accuracy - 2% are presented for carbon, aluminium, copper, indium, tungsten, bismuth and uranium targets. The dependence of cross sections on atomic number of the target coincides except of cross section of interaction with heavy targets

Experimental studies of pion-nucleus and nucleon-nucleus interactions at intermediate energies. Progress report, April 1, 1991--March 31, 1994

International Nuclear Information System (INIS)

1993-01-01

This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991-94 under a grant from the U.S. Department of Energy. Most of these studies involved investigations of various pion-nucleus interactions and nucleon-nucleus charge-exchange reactions. The work was carried out with the LAMPF accelerator at the Los Alamos National Laboratory and the cyclotrons at the Paul Scherrer Institute (PSI) near Zurich, Switzerland, at Indiana University (IUCF), and at TRIUMF in Vancouver, Canada, as collaborative efforts among several laboratories and universities. We have also worked on plans and preparations for new experiments involving studies of the quark structure of nucleons and nuclei, which would be carried out at Fermilab (FNAL), near Chicago, and at the HERA facility at the DESY laboratory in Hamburg, Germany. The NMSU personnel included two faculty members, five postdoctoral research associates, nine graduate students, and one undergraduate student

Building the nucleus from quarks: The cloudy bag model and the quark description of the nucleon-nucleon wave functions

International Nuclear Information System (INIS)

Miller, G.A.

1984-01-01

In the Cloudy Bag Model hadrons are treated as quarks confined in an M.I.T. bag that is surrounded by a cloud of pions. Computations of the charge and magnetism distributions of nucleons and baryons, pion-nucleon scattering, and the strong and electromagnetic decays of mesons are discussed. Agreement with experimental results is excellent if the nucleon bag radius is in the range between 0.8 and 1.1 fm. Underlying qualitative reasons which cause the pionic corrections to be of the obtained sizes are analyzed. If bags are of such reasonably large sizes, nucleon bags in nuclei will often come into contact. As a result one needs to consider whether explicit quark degrees of freedom are relevant for Nuclear Physics. To study such possibilities a model which treats a nucleus as a collection of baryons, pions and six-quark bags is discussed. In particular, the short distance part of a nucleon-nucleon wave function is treated as six quarks confined in a bag. This approach is used to study the proton-proton weak interaction, the asymptotic D to S state ratio of the deuteron, the pp → dπ reaction, the charge density of /sup 3/He, magnetic moments of /sup 3/He and /sup 3/H and, the /sup 3/He-/sup 3/H binding energy difference. It is found that quark effects are very relevant for understanding nuclear properties

Spin-dependent parton distributions in the nucleon

Energy Technology Data Exchange (ETDEWEB)

Cloet, I.C. [Special Research Centre for the Subatomic Structure of Matter and Department of Physics and Mathematical Physics, University of Adelaide, SA 5005 (Australia); Bentz, W. [Department of Physics, School of Science, Tokai University Hiratsuka-shi, Kanagawa 259-1292 (Japan); Thomas, A.W. [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2005-04-15

Spin-dependent quark light-cone momentum distributions are calculated for a nucleon in the nuclear medium. We utilize a modified NJL model where the nucleon is described as a composite quark-diquark state. Scalar and vector mean fields are incorporated in the nuclear medium and these fields couple to the confined quarks in the nucleon. The effect of these fields on the spin-dependent distributions and consequently the axial charges is investigated. Our results for the 'spin-dependent EMC effect' are also discussed.

Momentum loss in proton-nucleus and nucleus-nucleus collisions

International Nuclear Information System (INIS)

Khan, F.; Townsend, L.W.

1993-12-01

An optical model description, based on multiple scattering theory, of longitudinal momentum loss in proton-nucleus and nucleus-nucleus collisions is presented. The crucial role of the imaginary component of the nucleon-nucleon transition matrix in accounting for longitudinal momentum transfer is demonstrated. Results obtained with this model are compared with Intranuclear Cascade (INC) calculations, as well as with predictions from Vlasov-Uehling-Uhlenbeck (VUU) and quantum molecular dynamics (QMD) simulations. Comparisons are also made with experimental data where available. These indicate that the present model is adequate to account for longitudinal momentum transfer in both proton-nucleus and nucleus-nucleus collisions over a wide range of energies

Target fragmentation in proton-nucleus and16O-nucleus reactions at 60 and 200 GeV/nucleon

Science.gov (United States)

Albrecht, R.; Awes, T. C.; Baktash, C.; Beckmann, P.; Claesson, G.; Berger, F.; Bock, R.; Dragon, L.; Ferguson, R. L.; Franz, A.; Garpman, S.; Glasow, R.; Gustafsson, H. Å.; Gutbrod, H. H.; Kampert, K. H.; Kolb, B. W.; Kristiansson, P.; Lee, I. Y.; Löhner, H.; Lund, I.; Obenshain, F. E.; Oskarsson, A.; Otterlund, I.; Peitzmann, T.; Persson, S.; Plasil, F.; Poskanzer, A. M.; Purschke, M.; Ritter, H. G.; Santo, R.; Schmidt, H. R.; Siemiarczuk, T.; Sorensen, S. P.; Stenlund, E.; Young, G. R.

1988-03-01

Target remnants with ZPlastic Ball detector. The excitation energy of the target spectator matter in central oxygen-induced collisions is found to be high enough to allow for complete disintegration of the target nucleus into fragments with Z<3. The average longitudinal momentum transfer per proton to the target in central collisions is considerably higher in the case of16O-induced reactions (≈300 MeV/c) than in proton-induced reactions (≈130 MeV/c). The baryon rapidity distributions are roughly in agreement with one-fluid hydrodynamical calculations at 60 GeV/nucleon16O+Au but are in disagreement at 200 GeV/nucleon, indicating the higher degree of transparency at the higher bombarding energy. Both, the transverse momenta of target spectators and the entropy produced in the target fragmentation region are compared to those attained in head-on collisions of two heavy nuclei at Bevalac energies. They are found to be comparable or do even exceed the values for the participant matter at beam energies of about 1 2 GeV/nucleon.

Medium energy nucleon-nucleus scattering theory by semi-classical distorted wave approximation

Energy Technology Data Exchange (ETDEWEB)

Ogata, Kazuyuki [Kyushu Univ., Fukuoka (Japan)

1998-07-01

The semiclassical distorted wave model (SCDW) is one of the quantum mechanical models for nucleon inelastic and charge exchange scattering at intermediate energies. SCDW can reproduce the double differential inclusive cross sections for multi-step direct processes quite well in the angular and outgoing energy regions where the model is expected to work. But the model hitherto assumed on-the-energy-shell (on-shell) nucleon-nucleon scattering in the nucleus, neglecting the difference in the distorting potentials for the incoming and the outgoing particles and also the Q-value in the case of (p,n) reactions. There had also been a problem in the treatment of the exchange of colliding nucleons. Now we modify the model to overcome those problems and put SCDW on sounder theoretical foundations. The modification results in slight reduction (increase) of double differential cross sections at forward (backward) angles. We also examine the effect of the in-medium modification of N-N cross sections in SCDW and find it small. A remedy of the disagreement at very small and large angles in terms of the Wigner transform of the single particle density matrix is also discussed. This improvement gives very promising results. (author)

Secondary particle multiplicity depending on the collisions of π--mesons with 12C nucleons at p=40 GeV/c

International Nuclear Information System (INIS)

Angelov, N.S.; Grishin, V.G.; Nad', Yu.; Kanarek, T.; Batskovich, S.

1978-01-01

The multiplicities of secondary charged particles in π -12 C-interactions with ν-protons of carbon nucleus at p=40 GeV/c (ν=1-5) is presented. It is shown that the dependence of the average values of particle multiplicities on ν approximately equals the dependence on initial pion energy in π - p-interactions in the range from 40 to 200 GeV. KNO scaling and the Wroblewski empirical law for interactions with several nucleons of 12 C nucleus are observed

Discrepancies between global nucleon-nucleon phase shifts and new data for n-p scattering at 16.9 MeV

International Nuclear Information System (INIS)

Tornow, W.; Lisowski, P.W.; Byrd, R.C.; Walter, R.L.

1977-01-01

Data for the analyzing power A/sub y/(theta) for n-p scattering at 16.9 MeV have been measured for the range from 50 to 145 0 (c.m.). Eleven values are reported to an accuracy of about +- 0.002, the highest overall precision ever obtained in any fast-neutron polarization experiment. Predictions based on phase-shift sets obtained from global analyses of nucleon-nucleon scattering disagree significantly with the new data. The data are sufficiently precise to show a dependence on the f-wave spin-orbit phase parameter

Target dependence of central rapidity Λ production in sulfur-nucleus collisions at 200 GeV/c per nucleon

International Nuclear Information System (INIS)

Andersen, E.; Barnes, P.D.; Blaes, R.; Braun, H.; Brom, J.M.; Castano, B.; Cherney, M.; Cohler, M.; Cruz, B. de la; Diebold, G.E.; Fernandez, C.; Franklin, G.; Garabatos, C.; Garzon, J.A.; Geist, W.M.; Greiner, D.; Gruhn, C.; Hafidouni, M.; Hrubec, J.; Huss, D.; Jacquot, J.L.; Jones, P.G.; Kuipers, J.P.M.; Ladrem, M.; Ladron de Guevara, P.; Liko, D.; Lopez-Ponte, S.; Lovhoiden, G.; MacNaughton, J.; Maher, C.J.; Michalon, A.; Michalon-Mentzer, M.E.; Mosquera, J.; Natkaniec, Z.; Nelson, J.M.; Neuhofer, G.; Perez de los Heros, C.; Plo, M.; Porth, P.; Powell, B.; Quinn, B.; Ramil, A.; Riester, J.L.; Rohringer, H.; Sakrejda, G.; Sakrejda, I.; Thorsteinsen, T.; Traxler, J.; Voltolini, C.; Yanez, A.; Yepes, P.; Zybert, R.

1992-01-01

Central rapidity Λ production has been measured in sulfur collisions with Cu, Ag, and Pb at 200 GeV/c per nucleon. Lambdas produced in these collisions were identified by their charged decays recorded by a time projection chamber. The Λ yields are compared as a function of target mass. For each target, the yields are reported as a function of Λ transverse kinetic energy and zero degree energy (a measure of collision centrality). In each system, the data exceed predictions of the VENUS size-2(4.02) model of sulfur-nucleus collisions. The observed excesses show no obvious variation with collision centrality from moderate to highly central collisions

Mechanisms of High Energy Hadron-Nucleus and Nucleus-Nucleus Collision Processes

International Nuclear Information System (INIS)

Strugalski, Z.

1994-01-01

Mechanisms of high energy hadron-nucleus and nucleus-nucleus collision processes are depicted qualitatively, as prompted experimentally. In hadron-nucleus collisions the interaction of the incident hadron in intranuclear matter is localized in small cylindrical volume, with the radius as large as the strong interaction range is, centered on the hadron course in the nucleus. The nucleon emission is induced by the hadron in its passing through the nucleus; particles are produced via intermediate objects produced in 2 → 2 endoergic reactions of the hadron and its successors with downstream nucleons. In nucleus-nucleus collisions, the outcome of the reaction appears as the composition of statistically independent hadron-nucleus collision outcomes at various impact parameters. Observable effects supporting such mechanisms are discussed. 51 refs

Spin observables in nucleon-nucleus scattering

International Nuclear Information System (INIS)

Moss, J.M.

1982-01-01

The curse of inelastic nucleon scattering and charge exchange has always been the enormous complexity of the nucleon-nucleon (N-N) interaction. This complexity, however, can also be viewed as the ultimate promise of nucleons as probes of nuclear structure. Given an adequate theoretical basis, inelastic nucleon scattering is capable of providing information not obtainable with other probes. Recently a revolution of experimental technique has taken place that makes it desirable to re-examine the question of what physics is ultimately obtainable from inelastic nucleon scattering. It is now feasible to perform complete polarization transfer (PT) experiments for inelastic proton scattering with high efficiency and excellent energy resolution. Programs to measure PT obsevables are underway at several laboratories, and results are beginning to appear. Objectives of this presentation are to examine how such experiments are done, and what physics is presently obtained and may ultimately be learned from them

The evolution time of nucleon spectrum in residual excited nucleus and calculation of the non-linear effects

International Nuclear Information System (INIS)

Kenzhebaev, Sh.K.; Djuraev, Sh.H.; Mannanov, D.E.; Khugaev, A.V.

1994-01-01

The investigation of nonstationary fermi-gas thermalization of nucleons in the residual excited nucleus as an open nonlinearize system and analytical methods of calculation are presented. (author). 9 refs

Effective number of inelastically interacting nucleons in rare nucleus-nucleus production processes

International Nuclear Information System (INIS)

Korotkikh, V.L.; Lokhtin, I.P.

1992-01-01

A model of nucleus-nucleus interaction using one inelastic NN-interaction is suggested for the exclusive production processes with small cross-section. A-dependence nuclear coherent and incoherent production cross-section are predicted. 20 refs.; 4 figs

Global features of nucleus-nucleus collisions in ultrarelativistic domain

International Nuclear Information System (INIS)

Savina, M.V.; Shmatov, S.V.; Slavin, N.V.; Zarubin, P.I.

1998-01-01

HIJING generator simulation of nucleus-nucleus collisions at ultrarelativistic energies is presented. It is shown that the global characteristics of nucleus-nucleus collisions, such as distribution of a charged multiplicity, total and electromagnetic transverse energy over pseudorapidity are rather sensitive to some predictions of models of high-exited nuclear medium formation, namely parton energy losses in dense nuclear matter. These losses result in appearance of a broad maximum in global variable distributions over pseudorapidity. The most profound of this effect occurs at central heavy ion collisions at LHC energy

Symmetry energy, its density slope, and neutron-proton effective mass splitting at normal density extracted from global nucleon optical potentials

International Nuclear Information System (INIS)

Xu Chang; Li Baoan; Chen Liewen

2010-01-01

Based on the Hugenholtz-Van Hove theorem, it is shown that both the symmetry energy E sym (ρ) and its density slope L(ρ) at normal density ρ 0 are completely determined by the nucleon global optical potentials. The latter can be extracted directly from nucleon-nucleus scatterings, (p,n) charge-exchange reactions, and single-particle energy levels of bound states. Averaging all phenomenological isovector nucleon potentials constrained by world data available in the literature since 1969, the best estimates of E sym (ρ 0 )=31.3 MeV and L(ρ 0 )=52.7 MeV are simultaneously obtained. Moreover, the corresponding neutron-proton effective mass splitting in neutron-rich matter of isospin asymmetry δ is estimated to be (m n * -m p * )/m=0.32δ.

Asymmetries in angular distributions of nucleon emission intensity in high energy hadron-nucleus collisions

International Nuclear Information System (INIS)

Strugalski, Z.

1982-01-01

Asymmetry in nucleon emission intensity angular distributions relatively to the hadron deflection plane and to two planes normal to it and related to it uniquely is analyzed, using appropriate experimental data on pion-xenon nucleus collisions at 3.5 GeV/c momentum. Quantative characteristics of the asymmetries found are presented in tables and on figures

Charge dependence and charge asymmetry in the nucleon-nucleon interaction due to processes involving Δ's

International Nuclear Information System (INIS)

Wells, T.B.

1978-01-01

The charge dependence and charge asymmetry of the nucleon-nucleon force arising from the exchange of a pion and a photon with the excitation of a nucleon resonance [Δ(1236)] is calculated. This charge dependence and asymmetry is studied through its effects on the 1 S nucleon-nucleon scattering lengths. The complexity of the calculation forces the use of approximations. The calculation is performed first with a pole approximation for the resonance and a second time with a Chew-Low description of the resonance. Both calculations neglect nuclear recoil. Estimates of this effect are made. The changes in the scattering lengths are small ( +- / 2 = 1.0225 G/sub π 0 / 2 will explain the proton-neutron scattering length

Role of delta excitations in pion-, photon- and nucleon-nucleus reactions studied with microscopic models

International Nuclear Information System (INIS)

Engel, A.

1995-01-01

Delta excitation plays a prominent role in intermediate heavy reactions. In this paper, comment is made on the calculations done for pion-, photon- and nucleon-nucleus reactions using the Boltzmann-Uehling-Uhlenbeck (BUU) model and the antisymmetrized molecular dynamics (AMD) model. First, it is recalled how to include delta degrees in microscopic models in general. Then, the comparison of the microscopic calculation performed by the author with the experimental data is presented. Deltas in microscopic models are discussed. Pion-nucleus reactions have been studied since pion beams became available, especially for exploring the delta resonance in a nuclear medium. The dependence of pion absorption cross section on incident pion energy is shown. The photon-induced pion production in the resonance energy region was studied with the BUU model. The calculated results of neutral pion photo-production are shown. In both inelastic proton scattering and (p,n) charge exchange reaction, the excitation of delta resonance can be observed clearly in the experimental data. The results of the AMD calculation for 12 C(p,p') reaction are shown. (K.I.)

Global phenomenological optical model potential for nucleon-actinide reactions at energies up to 300 MeV

International Nuclear Information System (INIS)

Han Yinlu; Liang Haiying; Guo Hairui; Shen Qingbiao; Xu Yongli

2010-01-01

A set of new global phenomenological optical model potential parameters for the actinide region with incident nucleon energies from 1 keV up to 300 MeV is obtained. They are based on a smooth, unique functional form for the energy dependence of the potential depths and on physically constrained geometry parameters. The available experimental data including the neutron total cross sections, nonelastic cross sections, elastic scattering cross sections, elastic scattering angular distributions, and proton reaction cross sections and elastic scattering angular distributions of 232 Th and 238 U are used. The new nucleon global optical model potential parameters obtained are analyzed and used to analyze the experimental data of nucleon-actinide reactions. It is found that the present form of the global optical model potential could reproduce both the neutron and the proton experimental data.

Nucleus-nucleus potential with repulsive core and elastic scattering. Part 1. Nucleus-nucleus interaction potential

International Nuclear Information System (INIS)

Davidovs'ka, O.Yi.; Denisov, V.Yu.; Nesterov, V.O.

2010-01-01

Various approaches for nucleus-nucleus interaction potential evaluation are discussed in details. It is shown that the antisymmetrization of nucleons belonging to different nuclei and the Pauli principle give the essential contribution into the nucleus-nucleus potential at distances, when nuclei are strongly overlapping, and lead to appearance of the repulsive core of nucleus nucleus interaction at small distances between nuclei.

Study of Λ-production in central nucleus-nucleus interactions at the momentum of 4.6 GeV/c per incident nucleon

International Nuclear Information System (INIS)

Anikina, M.; Golokhvastov, A.; Goncharova, L.

1983-01-01

Transverse momenta and rapidities of Λ particles produced in central nucleus-nucleus collisions at 4.5 GeV/c per nucleon (cC, CNe, ONe, CCu, CZr, CPb, OPb) have been studied and compared with those from ineiolastic He-Li interactns at the same incident momentum. Polarization of Λ hyperons was found to be consistent (within the errors) with zero (αP=-0.06+-0.11) for 224 Λ particles from central collisions. The upper limit of anti Λ/Λ production ratio was estimated to be less than 10 -2 at a 90% confidence level. The analyzed experimental data were obtained using the triggered 2 m streamer spectrometer SKM-200

Interacting gluon model for hadron-nucleus and nucleus-nucleus collisions in the central rapidity region

International Nuclear Information System (INIS)

Fowler, G.N.; Navarra, F.S.; Plumer, M.; Lawrence Berkeley Laboratory, Nuclear Science Division, Berkeley, California 94720); Vourdas, A.; Weiner, R.M.

1989-01-01

The interacting gluon model developed to describe the inelasticity distribution in hadron-nucleon collisions has been generalized and applied to hadron-nucleus and nucleus-nucleus interactions. Leading particle spectra and energy distributions in hadron-nucleus and nucleus-nucleus collisions are calculated

Charged pion coherent production in nucleus-nucleus collisions at incident energies between 86 and 330 MeV/nucleon

International Nuclear Information System (INIS)

Fassnacht, P.

1984-01-01

We have studied pion production in nucleus-nucleus collisions at foward angles for about twenty projectile target combinations. The incident energies were below or around 300 MeV/nucleon which is the threshold of the elementary reaction NN → NNπ. The study of the inclusive spectra shows some new ideas: shell effects in pion production, collective resonances excitations. These spectra have been analyzed following different models: hard-scattering models which describe the interaction on the basis of the elementary reaction NN → NNπ, statistical model and the pionic cloud model which is a coherent description of the interaction. In the study of the exclusive reactions, we established some empiric rules concerning the cross-section variations. These exclusive spectra were then analyzed in the framework of two-models: the semi-phenomenological model and the pionic fusion [fr

Nucleon-nucleus inelastic scattering using a relativistic impulse approximation with exchange

International Nuclear Information System (INIS)

Rost, E.; Shepard, J.R.

1987-01-01

We formulate a microscopic relativistic treatment of nucleon-nucleus inelastic scattering in a distorted wave impulse approximation. The interaction is taken from a Lorentz invariant formulation with explicit direct and exchange terms constrained by fitting to experimental NN amplitudes. This procedure allows us to apply the theory in the lower range of intermediate energies (100--400 MeV) where exchange effects are likely to be important. Application to inelastic scattering uses this interaction for both the distorting potentials and the transition interaction. Effects of explicit exchange are studied and a preliminary analysis of /sup 12/C(p,p') data is presented

Angular momentum and incident-energy dependence of nucleus-nucleus interaction

International Nuclear Information System (INIS)

Yamaguchi, S.

1991-01-01

The purpose of this paper is to understand intuitively the origin of the angular momentum and incident-energy dependence of the nucleus-nucleus interaction on the basis of the totally- antisymmetrized many-body theory. With the aim of understanding the structure of the nucleus-nucleus interaction, we show first that the nucleus-nucleus interaction can be written by the use of the density-distribution function and the phase-space distribution function instead of using the many-body wave function itself. And we show that the structure change of the density-distribution function with the increase of the angular momentum causes the angular momentum dependence of the nucleus-nucleus interaction and that the incident-energy dependence of the nucleus-nucleus interaction originates from the structure change of the phase-space distribution function

Relationship between Feshbach's and Green's function theories of the nucleon-nucleus mean field

International Nuclear Information System (INIS)

Capuzzi, F.; Mahaux, C.

1995-01-01

We clarify the relationship and difference between theories of the optical-model potential which had previously been developed in the framework of Feshbach's projection operator approach to nuclear reactions and of Green's function theory, respectively. For definiteness, we consider the nucleon-nucleus system but all results can readily be adapted to the atomic case. The effects of antisymmetrization are properly taken into account. It is shown that one can develop along closely parallel lines the theories of open-quotes holeclose quotes and open-quotes particleclose quotes mean fields. The open-quotes holeclose quotes one-body Hamiltonians describe the single-particle properties of the system formed when one nucleon is taken away from the target ground state, for instance in knockout of pickup processes. The particle one-body Hamiltonians are associated with the system formed when one nucleon is elastically scattered from the ground state, or is added to it by means of stripping reactions. An infinite number of particle, as well as of hole, Hamiltonians are constructed which all yield exactly the same single-particle wave functions. Many open-quotes equivalentclose quotes one-body Hamiltonians can coexist because these operators have a complicated structure: they are nonlocal, complex, and energy-dependent. They do not have the same analytic properties in the complex energy plane. Their real and imaginary parts fulfill dispersion relations which may be different. It is shown that hole and particle Hamiltonians can also be constructed by decomposing any vector of the Hilbert space into two parts which are not orthogonal to one another, in contrast to Feshbach's original theory; one interest of this procedure is that the construction and properties of the corresponding hole Hamiltonian can be justified in a mathematically rigorous way. We exhibit the relationship between the hole and particle Hamiltonians and the open-quotes mass operator.close quotes

Transverse and radial flow in intermediate energy nucleus-nucleus collisions

International Nuclear Information System (INIS)

Vestfall, D. Gary

1997-01-01

We have studied transverse and radial flow in nucleus-nucleus collisions ranging in energy from 15 to 155 MeV/nucleon. We have measured the impact parameter dependence of the balance energy for Ar + Sc and compared the results with Quantum Molecular Dynamics calculations with and without momentum dependence. We have shown that transverse flow and the balance energy dependence on the isospin of the system using the systems 58 Fe + 58 Fe, 58 Ni + 58 Ni, and 58 Mn + 58 Fe. These results are compared with Boltzmann-Uehling-Uehlenbeck calculations incorporating isospin-dependence. We have measured radial flow for Ar + Sc and find that about 50% of the observed energy is related to radial flow. (author)

Study on isotopic distribution produced by nucleus-nucleus collisions with modified SAA model

International Nuclear Information System (INIS)

Zhong Chen; Fang Deqing; Cai Xiangzhou; Shen Wenqing; Zhang Huyong; Wei Yibin; Ma Yugang

2003-01-01

Base on Brohm's Statistic-Ablation-Abrasion (SAA) model, the modified SAA model was developed via introducing the isospin dependence of nucleon distribution in nucleus and parameterized formulas for nucleon-nucleon cross section in nuclear matter. It can simulate well the isotopic distribution at both high and intermediate energies. By the improvement of computational method, the range of calculation of isotopic distribution can be increased from three order magnitude to eight order magnitude (even higher). It can reproduce experimental data and predict the isotopic distribution for very far from stability line which is very important from experimental viewpoint

Off-shell sensitivity, repulsive correlations and the pion-nucleus optical potential

Energy Technology Data Exchange (ETDEWEB)

Keister, B D [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

1977-07-01

Repulsive nucleon-nucleon correlations tend to reduce the dependence of pion-nucleus elastic scattering upon the off-shell pion-nucleon dynamics. However, optical potential calculations can in practice be quite sensitive to the particular choice of off-shell model parameters. It is argued that this sensitivity results from the nature of the optical potential as a one-body operator which introduces extra off-shell dependence not found in physical many-body process itself. Thus, one must be very careful in any attempt to extract correlation or off-shell information, or to predict pion-nucleus phase shifts, by means of an optical potential theory. Results of model calculations are presented for purposes of illustration.

K+-nucleus interaction

International Nuclear Information System (INIS)

Gibbs, W.R.

1984-01-01

The K + -nucleus system is reviewed and comparison with data is made. The principal conclusions are that the theoretical uncertainties in relating the K + -nucleus interaction to the K + -nucleon interaction are very small and hence the positive kaon makes an excellent probe of the nucleus. It is suggested that this particle may be more sensitive to non-nucleonic degrees of freedom (especially quarks) than classical probes

η production in proton-nucleus reactions

International Nuclear Information System (INIS)

Cassing, W.; Batko, G.; Vetter, T.; Wolf, G.

1991-01-01

The production of η-mesons in proton-nucleus reactions is analysed with respect to primary nucleon-nucleon (NN→NN η ) and secondary pion-nucleon (πN→ηN) production processes on the basis of Hartree-Fock groundstate momentum distributions and free on-shell production processes. The folding model adopted compares well for meson production with more involved simulations based on VUU transport equations. Similar to K + production in proton-nucleus reactions the η-mesons are primarily produced by the πN→ηN channel. However, η-mesons are absorbed in nuclei via excitation of the N * (1535) resonance which leads to strong distortions of the primordial spectra. On the other hand, the experimental mass dependence of the differential cross sections might yield information about the in-medium properties of this resonance. (orig.)

Experimental studies of the quark-gluon structure of nucleons and nuclei and of pion- and proton-nucleus interactions. Progress report, April 1, 1994--March 31, 1997

International Nuclear Information System (INIS)

1996-01-01

This report summarizes the work on experimental research in intermediate energy nuclear physics carried out by New Mexico State University from April 1, 1994, through March 31, 1996 under a grant from the US Department of Energy. During this period we began phasing out our programs of study of pion-nucleus and pion-nucleon interaction and of nucleon-nucleus charge-exchange reactions, which have been our major focus of the past two or three years. At the same time we continued moving in a new direction of research on studies of the internal structure of nucleons and nuclei in terms of quarks and gluons. The pion and nucleon work has been aimed at improving our understanding of the nature of pion and proton interactions in the nuclear medium and of various aspects of nuclear structure. The studies of the quark-gluon structure of nucleons are aimed at clarifying such problems as the nature of the quark sea and the relation of the nucleon spin to the spins of the quarks within the nucleon, questions which are of a very fundamental nature

WIMP-nucleus scattering in chiral effective theory

Science.gov (United States)

Cirigliano, Vincenzo; Graesser, Michael L.; Ovanesyan, Grigory

2012-10-01

We discuss long-distance QCD corrections to the WIMP-nucleon(s) interactions in the framework of chiral effective theory. For scalar-mediated WIMP-quark interactions, we calculate all the next-to-leading-order corrections to the WIMP-nucleus elastic cross-section, including two-nucleon amplitudes and recoil-energy dependent shifts to the single-nucleon scalar form factors. As a consequence, the scalar-mediated WIMP-nucleus cross-section cannot be parameterized in terms of just two quantities, namely the neutron and proton scalar form factors at zero momentum transfer, but additional parameters appear, depending on the short-distance WIMP-quark interaction. Moreover, multiplicative factorization of the cross-section into particle, nuclear and astro-particle parts is violated. In practice, while the new effects are of the natural size expected by chiral power counting, they become very important in those regions of parameter space where the leading order WIMP-nucleus amplitude is suppressed, including the so-called "isospin-violating dark matter" regime. In these regions of parameter space we find order-of-magnitude corrections to the total scattering rates and qualitative changes to the shape of recoil spectra.

Δ++ resonance production in multi-nucleon η-12C interactions at the momentum of 40GeV/c

International Nuclear Information System (INIS)

Huseynaliyev, Y.H; Rustamova, A.B; Huseynaliyeva, L.Y.

2012-01-01

Full text : Study of behavior of the characteristics in hadrons-nucleus interactions at high energy as a function of collision centrality. Centrality dependences are studied in relativistic and ultra-relativistic heavy-ion collisions too. In these experiments as a collision centrality the numbers of participant nucleons, the number of binary nucleon collisions and the mean number of projectile-nucleon interactions have been used. An easy option to set centrality is the use of the number of protons emitted in the reactions to consider multi-nucleon processes. By studying the multi-nucleon events in hadrons nucleon and nucleus interactions on a can get useful information about collective phenomena, for example formation of bound states of the resonances in the nucleus. Physics of these processes serves as a bridge that joins the study of mechanisms for the production of high-energy particles and new phases of strongly-interacting nuclear matter. As the characteristics of secondary particles the transverse momentum, cumulative number and kinetic energy dependences in laboratory frame of the R are studied. An invariant mass distribution of ηp pairs is constructed and the indication on occurrence of a Δ + + baryon resonance and relatively high contribution of deep-inelastic processes in multi-nucleon events are received

Scattering by bound nucleons

International Nuclear Information System (INIS)

Tezuka, Hirokazu.

1984-10-01

Scattering of a particle by bound nucleons is discussed. Effects of nucleons that are bound in a nucleus are taken as a structure function. The way how to calculate the structure function is given. (author)

The use of dispersion relations to construct unified nucleon optical potentials

International Nuclear Information System (INIS)

Hodgson, P.E.

1991-01-01

The dispersion relations provide a simple and accurate way of parametrizing the optical potential for a particular nucleus over a range of energies. A method is proposed for obtaining a global nucleon optical potential incorporating the dispersion relations. (author). 9 refs, 3 figs

Diffractive ''semioptical'' model for nucleus-nucleus collisions

International Nuclear Information System (INIS)

Barashenkov, V.S.; Musulmanbekov, Zh.Zh.

1979-01-01

Diffraction Glauber theory for nucleus-nucleus collisions is considered in approximation when the initial nucleus interacts as a whole with nucleons of the target nucleus. Such an approach, being intermediate between precise Glauber theory and its optical limit, essentially simplifies numerical calculations and gives a good agreement with experiments as well. (author)

Relationship between the symmetry energy and the single-nucleon potential in isospin-asymmetric nucleonic matter

International Nuclear Information System (INIS)

Xu, Chang; Li, Bao-An; Chen, Lie-Wen

2014-01-01

In this contribution, we review the most important physics presented originally in our recent publications. Some new analyses, insights and perspectives are also provided. We showed recently that the symmetry energy E sym (ρ) and its density slope L(ρ) at an arbitrary density ρ can be expressed analytically in terms of the magnitude and momentum dependence of the single-nucleon potentials using the Hugenholtz-Van Hove (HVH) theorem. These relationships provide new insights about the fundamental physics governing the density dependence of nuclear symmetry energy. Using the isospin and momentum (k) dependent MDI interaction as an example, the contribution of different terms in the single-nucleon potential to the E sym (ρ) and L(ρ) are analyzed in detail at different densities. It is shown that the behavior of E sym is mainly determined by the first-order symmetry potential U sym,1 (ρ, k) of the single-nucleon potential. The density slope L(ρ) depends not only on the first-order symmetry potential U sym,1 (ρ, k) but also on the second-order one U sym,2 (ρ, k). Both the U sym,1 (ρ, k) and U sym,2 (ρ, k) at normal density ρ 0 are constrained by the isospin- and momentum-dependent nucleon optical potential extracted from the available nucleon-nucleus scattering data. The U sym,2 (ρ, k) especially at high density and momentum affects significantly the L(ρ), but it is theoretically poorly understood and currently there is almost no experimental constraints known. (orig.)

Relationship between the symmetry energy and the single-nucleon potential in isospin-asymmetric nucleonic matter

Energy Technology Data Exchange (ETDEWEB)

Xu, Chang [Nanjing University, Department of Physics, Nanjing (China); Li, Bao-An [Texas A and M University-Commerce, Department of Physics and Astronomy, Commerce, Texas (United States); Chen, Lie-Wen [Shanghai Jiao Tong University, Department of Physics and Astronomy and Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai (China)

2014-02-15

In this contribution, we review the most important physics presented originally in our recent publications. Some new analyses, insights and perspectives are also provided. We showed recently that the symmetry energy E{sub sym} (ρ) and its density slope L(ρ) at an arbitrary density ρ can be expressed analytically in terms of the magnitude and momentum dependence of the single-nucleon potentials using the Hugenholtz-Van Hove (HVH) theorem. These relationships provide new insights about the fundamental physics governing the density dependence of nuclear symmetry energy. Using the isospin and momentum (k) dependent MDI interaction as an example, the contribution of different terms in the single-nucleon potential to the E{sub sym} (ρ) and L(ρ) are analyzed in detail at different densities. It is shown that the behavior of E{sub sym} is mainly determined by the first-order symmetry potential U{sub sym,1}(ρ, k) of the single-nucleon potential. The density slope L(ρ) depends not only on the first-order symmetry potential U{sub sym,1}(ρ, k) but also on the second-order one U{sub sym,2}(ρ, k). Both the U{sub sym,1}(ρ, k) and U{sub sym,2}(ρ, k) at normal density ρ {sub 0} are constrained by the isospin- and momentum-dependent nucleon optical potential extracted from the available nucleon-nucleus scattering data. The U{sub sym,2}(ρ, k) especially at high density and momentum affects significantly the L(ρ), but it is theoretically poorly understood and currently there is almost no experimental constraints known. (orig.)

Nuclear structure effects in multi-nucleon transfer and sequential fission reactions

International Nuclear Information System (INIS)

Biswas, D.C.

2001-01-01

The role of the nuclear structure in multi-nucleon transfer and sequential fission reactions has been discussed. The recent results on multi-nucleon transfer and transfer induced fission reaction, have brought out many interesting features in understanding the reaction mechanism and collective dynamics of heavy ion reactions. The structure of the projectile nucleus has strong influence on the transfer of multi-nucleons and/or clusters from the projectile to the target. The mechanism of multi-nucleon transfer between two heavy nuclei is a complex process which has a strong dependence on the ground state Q-value of the reaction as well as on the number of transferred nucleons

Is nucleon deformed?

International Nuclear Information System (INIS)

Abbas, Afsar

1992-01-01

The surprising answer to this question Is nucleon deformed? is : Yes. The evidence comes from a study of the quark model of the single nucleon and when it is found in a nucleus. It turns out that many of the long standing problems of the Naive Quark Model are taken care of if the nucleon is assumed to be deformed. Only one value of the parameter P D ∼1/4 (which specifies deformation) fits g A (the axial vector coupling constant) for all the semileptonic decay of baryons, the F/D ratio, the pion-nucleon-delta coupling constant fsub(πNΔ), the double delta coupling constant 1 fsub(πΔΔ), the Ml transition moment μΔN and g 1 p the spin structure function of proton 2 . All this gives strong hint that both neutron and proton are deformed. It is important to look for further signatures of this deformation. When this deformed nucleon finds itself in a nuclear medium its deformation decreases. So much that in a heavy nucleus the nucleons are actually spherical. We look into the Gamow-Teller strengths, magnetic moments and magnetic transition strengths in nuclei to study this property. (author). 15 refs

Nucleus-Nucleus Scattering in the High-Energy Approximation and the Optical Folding Potential

CERN Document Server

Lukyanov, V K; Lukyanov, K V

2004-01-01

For the nucleus-nucleus scattering, the complex potential is obtained which corresponds to the eikonal phase of an optical limit of the Glauber-Sitenko high-energy approximation. The potential does not include free parameters, its real and imaginary parts depend on energy and are determined by the reported data on the nuclear density distributions and nucleon-nucleon scattering amplitude. Alternatively, for the real part, the folding potential can be utilized which includes the effective NN-forces and the exchange term, as well. As a result, the microscopic optical potential is constructed where contributions of the calculated real and imaginary parts are formed by fitting the two respective factors. An efficient of the approach is confirmed by agreements of calculations with the experimental data on elastic scattering cross-sections.

Transport theory applied to hadron and light fragment production in high energy nucleus-nucleus collisions

International Nuclear Information System (INIS)

Schuermann, B.; Malfliet, R.; Mies, S.; Zwermann, W.

1984-01-01

Foundations of the transport theory for studying K + , K - , π - and light fragment production in nucleus-nucleus interactions at high energies are given. Inclusive production of protons, K + and π - in the Ne+NaF reaction at 400 MeV and 21 GeV/nucleon is consdered, their differential cross sections are caculated. Differential cross sections of K - and π - production in Si+Si → K + +X and Ne+NaF → π - +X reactions at the energy of 2.1 GeV/nucleon, their energy dependence are estimated. Comparison of the calculated and experimental data is graphically presented. The model of the transport theory is shown to successfully reproduce inclusive spectra of different particles (p, d, π, K + , K - ) in a wide energy range of incident particles (from 400 MeV to 2 GeV/nucleon). This approach can be generalized for lower energies by generating a mean nuclear potentiasl field

Multi-quark effects in high energy nucleon-nucleon and nucleus-nucleus collisions

International Nuclear Information System (INIS)

Besliu, C.; Caraciuc, I.; Jipa, A.; Olariu, A.; Topor-Pop, R.; Cotorobai, F.; Pantea, D.; Popa, L.; Popa, V.; Topor-Pop, V.

1988-02-01

Recent data obtained in two experiments performed in the framework of the Bucharest-Dubna collaboration are presented, i.e.: the observation of narrow dibaryonic resonances is neutron-proton interactions in 1mHBC at different momenta of incident neutrons in the range 1-5 GeV/c, and the cumulative production of negative pions in nucleus-nucleus interactions in SKM-200 streamer chamber at 4.5 GeV/c. (authors)

K+ nucleus total cross sections

International Nuclear Information System (INIS)

Sawafta, R.

1990-01-01

The scattering of K + mesons from nuclei has attracted considerable interest in the last few years. The K + holds a very special position as the weakest of all strongly interaction probes. The average cross section is not larger than about 10 mb at lab momenta below 800 MeV/c, corresponding to a mean free path in the nucleus larger than 5 fm. Thus the K + is capable of probing the entire volume of the nucleus. Single scattering of the K + with a nucleon in the nucleus dominates the nuclear scattering, and only small and calculable higher order corrections are needed. The nucleon is a dynamical entity and its internal structure can, in principle, be altered by its surrounding nuclear environment. This work reports an experiment in which the K + is used to compare the nucleon in the nucleus with a free nucleon

The transverse-energy distributions of 32S-nucleus collisions at 200 GeV per nucleon

International Nuclear Information System (INIS)

Akesson, T.; Atherton, H.; Beker, H.; Bettoni, D.; Boeggild, H.; Dederichs, K.; Devenish, R.C.E.; En'yo, H.; Esten, M.J.; Fabjan, C.W.; Mazzoni, M.A.; Nilsson, S.; Piuz, F.; Poulard, G.; Price, M.; Russ, J.; Schukraft, J.; Sekimoto, M.; Seman, M.; Shotton, P.; Sletten, H.; Thodberg, H.H.; Veenhof, R.; Wigmans, R.; Willis, W.; Almehed, S.; Haglund, R.; Hedeberg, V.; Johansson, S.; Loerstad, B.; Mjoernmark, U.; Angelis, A.L.S.; Dodd, J.R.; Lessard, L.; McCubbin, M.L.; Armenise, N.; Muciaccia, M.T.; Simone, S.; Aubry, P.; Beaudoin, G.; Beaulieu, J.M.; Depommier, P.; Lounis, A.; Bartels, H.W.; Drees, A.; Fischer, P.; Glaessel, P.; Goerlach, U.; Hoelscher, A.; Kroh, V.; Neubert, M.; Pfeiffer, A.; Specht, H.J.; Benary, O.; Dagan, S.; Heifetz, R.; Marzari-Chiesa, A.; Masera, M.; Oren, Y.; Bisi, V.; Giubellino, P.; Ramello, L.; Riccati, L.; Blevis, I.; Fraenkel, Z.; Tserruya, I.; Cleland, W.; Clemen, M.; Collick, B.; Murray, M.; Park, Y.M.; Thompson, J.; Corriveau, F.; Hamel, L.A.; Jarlskog, G.; Lamarche, F.; Leroy, C.; Mazzucato, E.; Sirois, Y.; Dell'Uomo, S.; Di Liberto, S.; Meddi, F.; Rosa, G.; DiGiacomo, N.; Van Hecke, H.; Jacak, B.; McGaughey, P.; Sondheim, W.; Sunier, J.; Dolgoshein, B.; Kalinovski, A.; Kantserov, A.; Nevski, P.; Smirnov, S.; Sumarokov, A.; Tcherniatin, V.; Tikhomirov, V.; Berlandsson, B.; Sellden, B.; Gaidot, A.; Gibrat-Debu, F.; London, G.; Pansart, J.P.; Vasseur, G.; McCubbin, N.A.; Romano, G.; Sidorov, V.

1988-01-01

Transverse-energy distributions have been measured for the collisions of the 32 S nucleus with Al, Ag, W, Pt, Pb and U target nuclei, at an incident energy of 200 GeV per nucleon. The shapes of these distribution reflect the geometry of the collisions, including the deformation effects. For central collisions, the transverse-energy production in the region -0.1 lab 0.5 , where A is the atomic mass number of the target. This increase is accompanied by a relative depletion in the forward region η lab > 2.9. These results are compared with those obtained under similar conditions with incident 16 O nuclei. A comparison is also made with the predictions of a Monte Carlo generator based on the dual parton model. Finally, we give estimates of the energy density reached and its dependence on the atomic mass number of the projectile. (orig.)

Particle spectra and correlations in sulfur-nucleus reactions at 200 GeV per nucleon

International Nuclear Information System (INIS)

Alber, T.

1995-08-01

In this work the production of negatively charged particles and two-particle correlations in nucleus-nucleus reactions at high energies are studied. The range of the acceptance of experiment NA35 at the CERN-SPS was increased in 1990 by adding a large volume Time Projection Chamber downstream of the streamer chamber. The analysis of the data taken during the run period 1991 shows that such a detector faces no basic problems when operated in a high multiplicity experiment. The scenario of particle production in sulfur-nucleus reactions is studied via the measurement of rapidity and transverse momentum distributions which show good agreement with the results from other data-sets of the same experiment. The width of the rapidity distribution is only a little narrower than observed in nucleon-nucleon collisions and is in contradiction to the assumption of a static source with isotropic particle emission. The shape of the transverse momentum distribution indicates an effective temperature at freeze-out of about 150 MeV. The analysis of the two-particle correlation benefits particularly from the high statistics collected for different reactions in different phase-space regions. This allows a differential analysis of the correlation function for the different components of the momentum difference in various regions of rapidity and transverse momentum. It is recalled that for an expanding source the experimentally obtained radius parameters are not a direct measure of the geometrical size of the source but measure a so-called region of homogeneity. This expectation is also confirmed by a microscopic simulation of the reaction. The experimental results for the radius parameters support such a description of the particle production mechanism in terms of an expanding source. (orig.)

Factorization of secondary particle multiplicities in nucleus-nucleus collisions at energy of some GeV on the projectile nucleon; Faktorizatsiya mnozhestvennostej vtorichnykh chastits v yadro-yadernykh soudareniyakh pri ehnergii neskol`ko GehV na nuklon snaryada

Energy Technology Data Exchange (ETDEWEB)

Basova, E S; Zhumanov, A; Nasrullaeva, Kh; Nasyrov, Sk Z; Petrov, N V; Sadykov, N O; Svechnikova, L N; Trofimova, T P; Tuleeva, U I; Tursunov, B P

1992-03-01

The nuclear photographic emulsion method was used to study multiplicity of secondaries in interaction of some GeV on nucleon of {sup 132} Xe nucleus with photoemulsion. The formulas suggested describing the experimental data of normalized, mean and specific secondary particle multiplicity in nucleus-nucleus collisions at given energy. These formulas have evidence for the factorization of mean and specific multiplicities relatively the target and projectile nucleus mass number. (author). 10 refs., 5 figs., 4 tabs.

Transverse-momentum distribution of produced particles in ultrarelativistic nucleus-nucleus collisions

International Nuclear Information System (INIS)

Ban-Hao, S.; Wong, C.

1985-01-01

In order to discern coherent or collective processes from incoherent processes in nucleus-nucleus reactions at high energies, we study the transverse-momentum distribution of the produced particles with an incoherent-multiple-collision model. In this model, the projectile nucleon makes successive inelastic collisions with nucleons in the target nucleus, the probability of such collisions being given by the thickness function and the nucleon-nucleon inelastic cross section. It is assumed that each baryon-baryon collision produces particles and degrades momenta just as a baryon-baryon collision in free space, and that there are no secondary collisions between the produced particles and the nucleons. We found that the average transverse momentum and the charged-multiplicity data at Fermilab and CERN ISR energies can be well explained by such a model. However, the average transverse momentum for some events observed by the Japanese-American cooperative emulsion experiment (JACEE) associated with large energy density in the central rapidity region differ markedly from the model results. Such a deviation indicates the presence of coherent or collective effects for these collisions and may indicate the possibility of a formation of quark-gluon plasma

Microscopic model of nucleus-nucleus collisions

International Nuclear Information System (INIS)

Harvey, B.G.

1986-04-01

The collision of two nuclei is treated as a collection of collisions between the nucleons of the projectile and those of the target nucleus. The primary projectile fragments contain only those nucleons that did not undergo a collision. The inclusive and coincidence cross sections result from the decay of the excited primary fragments. 15 refs., 5 figs

Dynamics of hadron-nucleus interactions

International Nuclear Information System (INIS)

Wallace, S.J.

1981-07-01

Recent progress in diffraction theory shows that proton-nucleus scattering at nonforward angles is dominated by the interference of waves from two or more bright spots. Analytic formulas based on asymptotic theories of diffraction yield valuable new insights into the scattering and these formulas can be readily extended to illuminate the role of dynamical ingredients, i.e., the nucleon-nucleon amplitudes. The governing parameters of the diffraction and some direct connections between the observed cross sections and the input dynamics are reviewed. New information regarding the nucleon-nucleon parameters based on recent phase shift analyses show some systematic differences from the effective NN amplitudes which produce fits to proton-nucleus diffraction data. Recent progress in understanding the role of Δ-isobars in proton-nucleus dynamics is reviewed. 126 references

Charged particle production in proton-, deuteron-, oxygen- and sulphur-nucleus collisions at 200 GeV per nucleon

CERN Document Server

Alber, T.; Bachler, J.; Bartke, J.; Bialkowska, H.; Bloomer, M.A.; Bock, R.; Braithwaite, W.J.; Brinkmann, D.; Brockmann, R.; Buncic, P.; Chan, P.; Cramer, J.G.; Cramer, P.B.; Derado, I.; Eckardt, V.; Eschke, J.; Favuzzi, C.; Ferenc, D.; Fleischmann, B.; Foka, P.; Freund, P.; Fuchs, M.; Gazdzicki, M.; Gladysz, E.; Grebieszkow, J.; Gunther, J.; Harris, J.W.; Hoffmann, M.; Jacobs, P.; Kabana, S.; Kadija, K.; Keidel, R.; Kowalski, M.; Kuhmichel, A.; Lee, J.Y.; Ljubicic, A, Jr.; Margetis, S.; Mitchell, J.T.; Morse, R.; Nappi, E.; Odyniec, G.; Paic, G.; Panagiotou, A.D.; Petridis, A.; Piper, A.; Posa, F.; Poskanzer, Arthur M.; Puhlhofer, F.; Rauch, W.; Renfordt, R.; Retyk, W.; Rohrich, D.; Roland, G.; Rothard, H.; Runge, K.; Sandoval, A.; Schmitz, N.; Schmoetten, E.; Sendelbach, R.; Seyboth, P.; Seyerlein, J.; Skrzypczak, E.; Spinelli, P.; Stock, R.; Strobele, H.; Teitelbaum, L.; Tonse, S.; Trainor, T.A.; Vasileiadis, G.; Vassiliou, M.; Vesztergombi, G.; Vranic, D.; Wenig, S.; Wosiek, B.; Zhu, X.

1998-01-01

The transverse momentum and rapidity distributions of net protons and negatively charged hadrons have been measured for minimum bias proton-nucleus and deuteron-gold interactions, as well as central oxygen-gold and sulphur-nucleus collisions at 200 GeV per nucleon. The rapidity density of net protons at midrapidity in central nucleus-nucleus collisions increases both with target mass for sulphur projectiles and with the projectile mass for a gold target. The shape of the rapidity distributions of net protons forward of midrapidity for d+Au and central S+Au collisions is similar. The average rapidity loss is larger than 2 units of rapidity for reactions with the gold target. The transverse momentum spectra of net protons for all reactions can be described by a thermal distribution with `temperatures' between 145 +- 11 MeV (p+S interactions) and 244 +- 43 MeV (central S+Au collisions). The multiplicity of negatively charged hadrons increases with the mass of the colliding system. The shape of the transverse mom...

K sup + nucleus total cross sections

Energy Technology Data Exchange (ETDEWEB)

Sawafta, R.

1990-01-01

The scattering of K{sup +} mesons from nuclei has attracted considerable interest in the last few years. The K{sup +} holds a very special position as the weakest of all strongly interaction probes. The average cross section is not larger than about 10 mb at lab momenta below 800 MeV/c, corresponding to a mean free path in the nucleus larger than 5 fm. Thus the K{sup +} is capable of probing the entire volume of the nucleus. Single scattering of the K{sup +} with a nucleon in the nucleus dominates the nuclear scattering, and only small and calculable higher order corrections are needed. The nucleon is a dynamical entity and its internal structure can, in principle, be altered by its surrounding nuclear environment. This work reports an experiment in which the K{sup +} is used to compare the nucleon in the nucleus with a free nucleon.

Determination of the shapes and sizes of the regions in which in hadron-nucleus collisions reactions leading to the nucleon emission, particle production, and fragment evaporation occur

International Nuclear Information System (INIS)

Strugalski, Z.

1985-01-01

Shapes and sizes of the regions in target-nuclei in which reactions leading to the nucleon emission, particle production and fragment evaporation occur are determined. The region of nucleon emission is of cylindrical shape, with the diameter as large as two nucleon diameters, centered on the incident hadron course. The reactions leading to the particle production happen predominantly along the incident hadron course in nuclear matter. The fragment evaporation goes from the surface layer of the part of the target-nucleus damaged in nucleon emission process

Models of the atomic nucleus. Unification through a lattice of nucleons. 2. ed.

International Nuclear Information System (INIS)

Cook, Norman D.

2010-01-01

This book-and-software package supplies users with an interactive experience for nuclear visualization via a computer-graphical interface, similar in principle to the molecular visualizations already available in chemistry. Models of the Atomic Nucleus explains the nucleus in a way that makes nuclear physics as comprehensible as chemistry or cell biology. The book/software supplements virtually any of the current textbooks in nuclear physics by providing a means for 3D visual display of the diverse models of nuclear structure. For the first time, an easy-to-master software for scientific visualization of the nucleus makes this notoriously 'nonvisual' field become immediately 'visible.' After a review of the basics, the book explores and compares the competing models, and addresses how the lattice model best resolves remaining controversies. The appendix explains how to obtain the most from the software provided on extras.springer.com. This new edition has been updated completely and expanded to cover recent developments in low energy nuclear reactions (LENR), and to show how the fcc nucleon lattice explains both the asymmetric fragments produced by the fission of Uranium and the symmetric fragments produced by the fission of Palladium. The associated software to visualize the models of atomic nuclei had been rewritten and updated to include all new developments. (orig.)

On the nucleon effective mass role to the high energy proton spallation reactions

Energy Technology Data Exchange (ETDEWEB)

Santos, B.M., E-mail: biank_ce@if.uff.br [Instituto de Física, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, 24210-346 Niterói, RJ (Brazil); Instituto Militar de Engenharia, Praça General Tibúrcio 80, 22290-270 Rio de Janeiro, RJ (Brazil); Pinheiro, A.R.C. [Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro, RJ (Brazil); Universidade Federal do Acre, BR 364 km 04, 69920-900 Rio Branco, AC (Brazil); Gonçalves, M. [Comissão Nacional de Energia Nuclear, Rua General Severiano 90, 22290-901 Rio de Janeiro, RJ (Brazil); Duarte, S.B. [Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro, RJ (Brazil); Cabral, R.G. [Instituto Militar de Engenharia, Praça General Tibúrcio 80, 22290-270 Rio de Janeiro, RJ (Brazil)

2016-04-15

We explore the effect of the nucleon effective mass to the dynamic evolution of the rapid phase of proton–nucleus spallation reactions. The analysis of the relaxation time for the non-equilibrium phase is studied by variations in the effective mass parameter. We determine the final excitation energy of the hot residual nucleus at the end of cascade phase and the de-excitation of the nuclear system is carried out considering the competition of particle evaporation and fission processes. It was shown that the excitation energy depends of the hot compound residual nucleus at the end of the rapid phase on the changing effective mass. The multiplicity of particles was also analyzed in cascade and evaporation phase of the reaction. The use of nucleon effective mass during cascade phase can be considered as an effect of the many-body nuclear interactions not included explicitly in a treatment to the nucleon–nucleon interaction inside the nucleus. This procedure represents a more realistic scenario to obtain the neutron multiplicity generated in this reaction, which is a benchmark for the calculation of the neutronic in the ADS reactors.

Electromagnetic structure of a bound nucleon

International Nuclear Information System (INIS)

Nogami, Y.

1977-01-01

The effect of binding on the electromagnetic (e.m.) structure of a nucleon in a nucleus is examined by means of a model consisting of a single nucleon which is bound in a harmonic oscillator potential and also coupled to the pion field through the Chew-Low interaction. The 'two-pion contribution' to the e.m. structure is considered. This is the part which is probably most susceptible to the binding effect. By the binding effect it is meant the one which arises because the nucleon wave functions, in the intermediate state as well as in the initial and final states, are distorted by the potential in which the nucleon is bound. This may be compared to a similar correction to the impulse approximation for pion-nucleus scattering. Unlike the latter which is likely to be quite appreciable, the binding correction to the e.m. structure of the nucleon is found to be negligibly small. The so-called quenching effect due to the Pauli principle when there are other nucleons is also discussed [pt

Three nucleon interaction and nuclear composition

International Nuclear Information System (INIS)

Pandharipande, V.R.

1983-01-01

The author discusses results of some of the calculations carried out by J. Carlson, I. Lagaris, J. Lomnitz-Adler, R.A. Smith, R.B. Wiringa and himself to study the three nucleon interaction. The group has attempted to calculate the wavefunctions and binding energies of 3 H, 3 He, 4 He and nuclear matter, with the variational method, from a nonrelativistic Hamiltonian. Only nucleon degrees of freedom are retained in this Hamiltonian; the effects of other degrees of freedom are implicit in the two and three nucleon potentials. The author discusses further the calculations carried out, in collaboration with B. Friman, and R.B. Wiringa, to study the composition of nuclei. Nucleons interact by many processes including exchange of pions with or without excitation to isobar (Δ) states. Thus the nucleus contains pions being exchanged, and some nucleons in the Δ state. The group attempts to calculate the number and momentum distribution of these exchanged pions, and the fraction of time a nucleon in the nucleus is in the Δ state. 21 references, 4 figures

HIJET: a Monte Carlo event generator for P-nucleus-nucleus collisions

International Nuclear Information System (INIS)

Ludlam, T.; Pfoh, A.; Shor, A.

1985-01-01

Comparisons are shown for the HIJET generated data and measured data for average multiplicities, rapidity distributions, and leading proton spectra in proton-nucleus and heavy ion reactions. The algorithm for the generator is one of an incident particle on a target of uniformly distributed nucleons. The dynamics of the interaction limit secondary interactions in that only the leading baryon may re-interact with the nuclear volume. Energy and four momentum are globally conserved in each event. 6 refs., 6 figs

Transverse momentum dependence of Bose-Einstein correlations in S+nucleus collisions at 200 GeV/nucleon

International Nuclear Information System (INIS)

Morse, R.J.

1994-07-01

The NA35 experiment has collected a high statistics set of momentum analyzed negative hadrons near and forward of mid-rapidity for central collisions of 200 GeV/Nucleon 32 S projectiles incident on S, Ag and Au targets. Using two pion momentum space correlations in order to study the size of the source of particle production, small dependences upon transverse momentum are found for the transverse source dimensions; however for the heaviest system, R long decreases by about 40% as transverse momentum is increased over the interval 50 T < 600 MeV/c. Preliminary model calculations using a microscopic phase space approach (RQMD) appear to reproduce the observed characteristics of the data

Low-energy pion double charge exchange and nucleon-nucleon correlations in nuclei

International Nuclear Information System (INIS)

Leitch, M.J.

1989-01-01

Recent measurements of pion double-charge exchange (DCX) at energies 20 to 70 MeV are providing a new means for studying nucleon-nucleon correlations in nuclei. At these energies the nucleus is relatively transparent, allowing simpler theoretical models to be used in interpreting the data and leading to a clearer picture. Also the contribution to DCX of sequential charge-exchange scattering through the intermediate analog state is suppressed near 50 MeV and transitions through non-analog intermediate states become very important. Recent theoretical studies by several groups have shown that while transitions through the analog route involve relatively long nucleon-nucleon distances, those through non-analog intermediate states obtain nearly half their strength from nucleon pairs with less than 1 fermi separation. Thus DCX near 50 MeV is an excellent way to study short-range nucleon-nucleon correlations. 31 refs., 29 figs., 4 tabs

A global analysis of the elastic 3He scattering in the framework of the optical model

International Nuclear Information System (INIS)

Trost, H.J.

1981-01-01

The elastic scattering of 3 He at projetile energies from 10 MeV to 220 MeV on target nuclei in the mass range 10 to 208 is coherently studied in the framework of the simple optical model. It succeeds to obtain in the whole range a reasonable description by means of the usual Woods-Saxon potentials. This is illustrated by the presentation of a global mass and energy dependent potential. The light target nuclei are included in these systematics without the introduction of any special procedures. The omission of the antisymmetrization by the use of a purely local potential and the spin-orbit interaction have no important influence in the determination of the central potential. The cancelling of the discerte ambiguity is globally guaranted by the presented parametrization. The tradional sum rule 'number of projectile nucleons multiplied by nucleon-nucleus potential is equal to nucleus-nuclear potential' is not fulfilled. Starting from existing theoretical papers the properties of the global 3 He potential can be quantitatively explained. On the base of the 3 He potentials determined here and existing nucleon and deuteron potentials finally an approach to a projectile systematic is indicated. (orig.) [de

Nucleon-nucleus optical model up to 200 MeV. Proceedings of a specialist meeting

International Nuclear Information System (INIS)

OECD Nuclear Energy Agency; Commissariat a l'Energie Atomique

1997-01-01

The proceedings of the Specialists Meeting on Nucleon-Nucleus Optical Model up to 200 MeV contains papers on different topics in connection with the nuclear optical potential research. The purpose of the meeting was to reach a common understanding between nuclear theorists, experimentalists and the applied community on the most reliable approaches to predicting nuclear cross-sections in the medium energy region. The discussion centred around such questions as 'What are the better theoretical models today?', and 'What experimental data are required to test the models?'. 23 items are indexed separately for the INIS database. (K.A.)

Some experimental results of the investigation of hadron-nucleus and nucleus-nucleus interactions

International Nuclear Information System (INIS)

Azimov, S.A.; Gulamov, K.G.; Chernov, G.M.

1978-01-01

Recent experimental data on the hadron-nucleus and nucleus-nucleus inelastic interactions are analyzed. A particular attention is paid to the description of the leading hadron spectra and of the spectra of nucleon recoils in hadron-nucleus interactions. Some of the results of the experimental studies of correlations between secondary particles are discussed. This discussion demonstrates that an analysis of the multiparticle phenomena is very promising regarding the discrimination between the different models for the hadron-nucleus and nucleus-nucleus interactions. It is pointed out that the actual mechanism of the hadron-nucleus and nucleus-nucleus interactions is a rather complex one and can be described comprehensively by none of the existing models

Conclusions and recommendations emerging from the specialists meeting on the nucleon-nucleus optical model up to 200 MeV

International Nuclear Information System (INIS)

Madland, D.

1997-01-01

Conclusions of the specialists meeting on the nucleon-nucleus optical model up to 200 MeV are drawn, from both the experimental and the theoretical point of view. Five general approaches to the medium-energy optical potential are discussed: Dirac and Schroedinger phenomenological potentials, dispersive potentials, semi-microscopic potentials, microscopic potentials and coupled-channel potentials. (K.A.)

Probing nuclear structure with nucleons; Sonder la structure nucleaire avec des nucleons

Energy Technology Data Exchange (ETDEWEB)

Bauge, E. [CEA Bruyeres-le-Chatel, Service de Physique Nucl aire, 91 (France)

2007-07-01

The goal of this lecture is to show how nucleon scattering can be used to probe the structure of target nuclei, and how nucleon scattering observables can be interpreted in terms of nuclear structure using microscopic optical potentials. After a brief overview of the specificities of nucleon-nucleus scattering, and a quick reminder on scattering theory, the main part of this lecture is devoted to the construction of optical potentials in which the target nuclei structure information is folded with an effective interaction. Several examples of such microscopic optical model potentials are given. (author)

Collective flow studies in central collisions between nuclei at several hundreds of MeV per nucleon

International Nuclear Information System (INIS)

Demoulins, M.

1990-02-01

The main purpose for studying collisions between heavy nuclei, in the 200-2000 MeV per nucleon energy range, is to determine the equation of state and the properties of dense and hot nuclear matter. The insensitiveness of the inclusive data to the equation of state has led experimental physicists to build large solid angle detectors capable of detecting simultaneously the tens of particles emitted in each event. Such measurements allow to estimate the impact parameter, the reaction plane on an event-by-event basis, and to calculate various global variables involving all particles emitted in each event. In this thesis, we study global variables which characterize the nuclear matter collective flow in a direction which is different from the direction of incident motion, for argon-nucleus collisions at 400 and 600 MeV by nucleon and for neon-nucleus collisions at 400 and 800 MeV by nucleon. The measurements have been performed with the DIOGENE detector installed at SATURNE. For the argon-beam experiments, two parallel plate avalanche counters have been used to locate the interaction point of each incoming ion with the target, which improves the reconstruction of the particle tracks in the DIOGENE central chamber. Double differential cross-sections, in the reaction plane and in the plane orthogonal to the reaction plane, are fitted with two-dimensional Gaussian distributions. Through this procedure, we get rid of geometrical acceptance effects. Several quantities, related to the collective flow (flow angle, aspect ratios, flow parameter), are thus extracted and corrected for the fluctuations of the estimated reaction plane. For argon-nucleus collisions at 400 MeV by nucleon, our results are in agreement with results obtained by other groups with different methods. For argon-nucleus collisions, the discrepancy between our experimental results and predictions of intranuclear cascade calculations is increasing with the mass asymmetry of the colliding system [fr

Collective flow studies in central collisions between nuclei at several hundreds of MeV per nucleon

International Nuclear Information System (INIS)

Demoulins, M.

1989-01-01

The main purpose for studying collisions between heavy nuclei, in the 200-2000 MeV per nucleon energy range, is to determine the equation of state and the properties of dense and hot nuclear matter. The insensitiveness of the inclusive data to the equation of state has led experimental physicists to build large solid angle detectors capable of detecting simultaneously the tens of particles emitted in each event. Such measurements allow to estimate the impact parameter, the reaction plane on an event-by-event basis, and to calculate various global variables involving all particles emitted in each event. In this thesis, we study global variables which characterize the nuclear matter collective flow in a direction which is different from the direction of incident motion, for argon-nucleus collisions at 400 and 600 MeV by nucleon and for neon-nucleus collisions at 400 and 800 MeV by nucleon. The measurements have been performed with the DIOGENE detector installed at SATURNE. For the argon-beam experiments, two parallel plate avalanche counters have been used to locate the interaction point of each incoming ion with the target, which improves the reconstruction of the particle tracks in the DIOGENE central chamber. Double differential cross sections, in the reaction plane and in the plane orthogonal to the reaction plane, are fitted with two-dimensional Gaussian distributions. Through this procedure, we get rid of geometrical acceptance effects. Several quantities, related to the collective flow (flow angle, aspect ratios, flow parameter), are thus extracted and corrected for the fluctuations of the estimated reaction plane. For the argon-nucleus collisions at 400 MeV by nucleon, our results are in agreement with results obtained by other groups with different methods. For argon-nucleus collisions, the discrepancy between our experimental results and predictions of intranuclear cascade calculations is increasing with the mass asymmetry of the colliding system [fr

Structure functions of nucleons and nuclei

Energy Technology Data Exchange (ETDEWEB)

Bentz, Wolfgang; Ito, Takuya [Department of Physics, Tokai University, Kanagawa (Japan); Cloet, Ian [Department of Physics, University of Washington, Seattle (United States); Thomas, Anthony [Jefferson Lab., Newport News, VA (United States); Yazaki, Koichi [RIKEN, Wako-shi, Saitama (Japan)

2009-07-01

We use an effective chiral quark theory to calculate the quark distributions and structure functions of nucleons and nuclei. The description of the single nucleon is based on the Faddeev framework, and nuclear systems are described in the mean field approximation. Particular amphasis is put on the prediction of the polarized EMC effect in nuclei, and on applications to deep inelastic neutrino-nucleus scattering. Concerning the polarized EMC effect, we discuss the quenching of the quark spin sum in nuclei and its implications for the spin dependent nuclear structure functions, and present results for several nuclei where an experimental observation is feasible. Concerning the case of deep inelastic neutrino-nucleus scattering, we estimate the effect of medium modifications of the quark distribution functions on the measured cross sections, and discuss an interesting resolution of the so called NuTeV anomaly. Finally, we discuss extensions of our model to describe fragmentation functions for semi-inclusive processes. The connection between our effective quark model description and the jet model of Field and Feynman is discussed.

Hadron-nucleon inelastic collision mean free path in nuclear matter

International Nuclear Information System (INIS)

Strugalski, Z.

1980-01-01

Characteristics of atomic nuclei, used as targets in high energy hadron-nucleus collision experiments, are defined on the basis of the data on the nuclei sizes and radial nucleon density distributions in nuclei. Average mean free path for inelastic hadron-nucleon collisions in nuclei is estimated using existing experimental data on the pion-xenon nucleus collisions and the connection of it with the cross-section for hadron-nucleon elementary inelastic collisions is discussed

Experiments on few-nucleon systems at MAMI

International Nuclear Information System (INIS)

Distler, M.O. . Author

2008-01-01

The experimental effort at the Mainz Microtron with respect to few-body physics is focused on a number of selected topics. The structure of 3 He has been studied in the reactions 3 He(ε, εn) and 3 He(ε, ε'p) with large (transversal) missing momenta and in quasi-elastic electron scattering. Experiments to determine the neutron electric form factor G en have been performed - a measurement at a four-momentum transfer Q 2 ∼ 1.5(GeV/c) 2 took place in July 2007. Electromagnetically induced two-nucleon knockout has been investigated in order to study the role of correlated nucleon-nucleon motion in the nucleus. Measurements of the (e,e' pn) reaction on 3 He and 16 O were performed for the first time. A triple-polarization experiment of type 3 He(ε, ε'p)d has been performed in August 2007, where, in addition, the spin of the knocked-out proton is analyzed. This measurement provides information on the spin-dependent momentum distribution of proton-deuteron clusters in the 3 He nucleus. By using this deuteron-tagging method spin-polarized 3 He might also serve as an effective polarized proton target for electron scattering experiments. Presented at the 20th Few-Body Conference, Pisa, Italy, 10-14 September 2007. (author)

The origin of nuclear mass number dependence in EMC-effect

International Nuclear Information System (INIS)

Kurihara, Y.; Date, S.; Nakamura, A.; Sato, H.; Sumiyoshi, H.; Yoshinada, K.

1985-03-01

The origin of the mass number dependence of the nucleon structure functions extracted from the deep inelastic lepton-nucleus scattering is investigated by factorizing the structure function into A and x dependent parts. It is found that the mass number dependence is determined by the probability of exotic components in multi-nucleon overlap. This suggests that the deformation of the nucleon structure function is caused by the interaction among nucleons during their overlap. (author)

Models of the atomic nucleus. Unification through a lattice of nucleons. 2. ed.

Energy Technology Data Exchange (ETDEWEB)

Cook, Norman D. [Kansai Univ., Osaka (Japan). Dept. Informatics

2010-07-01

This book-and-software package supplies users with an interactive experience for nuclear visualization via a computer-graphical interface, similar in principle to the molecular visualizations already available in chemistry. Models of the Atomic Nucleus explains the nucleus in a way that makes nuclear physics as comprehensible as chemistry or cell biology. The book/software supplements virtually any of the current textbooks in nuclear physics by providing a means for 3D visual display of the diverse models of nuclear structure. For the first time, an easy-to-master software for scientific visualization of the nucleus makes this notoriously 'nonvisual' field become immediately 'visible.' After a review of the basics, the book explores and compares the competing models, and addresses how the lattice model best resolves remaining controversies. The appendix explains how to obtain the most from the software provided on extras.springer.com. This new edition has been updated completely and expanded to cover recent developments in low energy nuclear reactions (LENR), and to show how the fcc nucleon lattice explains both the asymmetric fragments produced by the fission of Uranium and the symmetric fragments produced by the fission of Palladium. The associated software to visualize the models of atomic nuclei had been rewritten and updated to include all new developments. (orig.)

Symmetry energy of nucleonic matter with tensor correlations

Science.gov (United States)

Hen, Or; Li, Bao-An; Guo, Wen-Jun; Weinstein, L. B.; Piasetzky, Eli

2015-02-01

The nuclear symmetry energy (Esym(ρ ) ) is a vital ingredient of our understanding of many processes, from heavy-ion collisions to neutron stars structure. While the total nuclear symmetry energy at nuclear saturation density (ρ0) is relatively well determined, its value at supranuclear densities is not. The latter can be better constrained by separately examining its kinetic and potential terms and their density dependencies. The kinetic term of the symmetry energy, Esymkin(ρ0) , equals the difference in the per-nucleon kinetic energy between pure neutron matter (PNM) and symmetric nuclear matter (SNM), often calculated using a simple Fermi gas model. However, experiments show that tensor force induced short-range correlations (SRC) between proton-neutron pairs shift nucleons to high momentum in SNM, where there are equal numbers of neutrons and protons, but have almost no effect in PNM. We present an approximate analytical expression for Esymkin(ρ0) of correlated nucleonic matter. In our model, Esymkin(ρ0) =-10 MeV, which differs significantly from +12.5 MeV for the widely-used free Fermi gas model. This result is consistent with our analysis of recent data on the free proton-to-neutron ratios measured in intermediate energy nucleus-nucleus collisions as well as with microscopic many-body calculations, and previous phenomenological extractions. We then use our calculated Esymkin(ρ ) in combination with the known total symmetry energy and its density dependence at saturation density to constrain the value and density dependence of the potential part and to extrapolate the total symmetry energy to supranuclear densities.

The imaginary part of the nucleus - nucleus optical potential

International Nuclear Information System (INIS)

Phatak, S.C.; Sinha, B.

1978-01-01

The contribution to the imaginary nucleus - nucleus optical potential has been estimated by evaluating the energy - conserving seocond-order term in the perturbation series. The incoming nuclear field is supposed to excite nucleons in a nucleus in this calculation and the nuclear excitations are approximated by particle-hole excitations in a Fermi gas. The resulting imaginary potential compares favourably with phenomenological potentials. (author)

Influence of the density dependence factor in effective nucleon-nucleon forces and interaction of 4He-particles with stable nuclei

International Nuclear Information System (INIS)

Kuterbekov, K.A.; Zholdybayev, T.K.; Muchamedzhan, A.; Penionzhkevich, Yu.E.; Kukhtina, I.N.

2004-01-01

Full text: The most popular method for join analysis of experimental angular distributions (AD) and total cross sections (TCS) at low and moderate energies is semimicroscopic folding model (SFM) [1]. Since 4 He-particle is a core of exotic nuclei 6,8 He, it is topical to continue systematic investigations at various effective nucleon-nucleon forces. In [2] we investigated for the first time energy and mass dependencies of the parameters SFM at low and moderate energies. At that, as effective forces between nucleons of the colliding nuclei were used total M3Y-interaction [3] and nucleon densities calculated by the method of density functional [4]. In the present work based on SFM there were investigated influences of the density dependence factor in effective nucleon-nucleon forces (4 force options considered) on calculation of ADs and TCSs at interaction of 4 He-particles with stable nuclei (A = 12 - 208) at α-particle energies 21 - 141.5 MeV. Corresponding experimental AD and TCS data used for model verification are of high quality with low error both for angular and energy diapason. Therefore, conclusions made in the performed investigation contain important quantitative information and are valuable for consequent comparative analysis of experimental data on interaction of light exotic nuclei with stable nuclei

Percolation Model of Nuclear Multifragmentation in High Energy Nucleus-Nucleus Interactions

International Nuclear Information System (INIS)

Abdel-Waged, Kh.

1994-01-01

A hybrid model based on Reggeon theory inspired model of nuclear distribution, which was successful in explaining the cascading of particles in high energy nucleus-nucleus interactions, and percolation model is proposed. In the framework of this model the yield of the fragment in p + Ag, Au at 350 GeV and C + Ag, Au at 3.6 GeV/nucleon as well as the charge distribution of fragments in Kr, Xe and U interactions with emulsion at ∼ 1 GeV/nucleon is correctly described. 32 refs., 3 figs

Nuclear transparency and effective kaon-nucleon cross section from the A(e,e'K+) reaction

International Nuclear Information System (INIS)

Nuruzzaman; Dutta, D.; Arrington, J.; Fassi, L. El; Zheng, X. C.; Asaturyan, R.; Mkrtchyan, H.; Navasardyan, T.; Tadevosyan, V.; Benmokhtar, F.; Boeglin, W.; Markowitz, P.; Bosted, P.; Bruell, A.; Chudakov, E.; Ent, R.; Fenker, H. C.; Gaskell, D.; Jones, M. K.; Lung, A. F.

2011-01-01

We have determined the transparency of the nuclear medium to kaons from A(e,e ' K + ) measurements on 12 C, 63 Cu, and 197 Au targets. The measurements were performed at the Jefferson Laboratory and span a range in four-momentum-transfer squared Q 2 =1.1-3.0 GeV 2 . The nuclear transparency was defined as the ratio of measured kaon electroproduction cross sections with respect to deuterium (σ A /σ D ). We further extracted the atomic number (A) dependence of the transparency as parametrized by T=(A/2) α-1 and, within a simple model assumption, the in-medium effective kaon-nucleon cross sections. The effective cross sections extracted from the electroproduction data were found to be smaller than the free cross sections determined from kaon-nucleon scattering experiments, and the parameter α was found to be significantly larger than those obtained from kaon-nucleus scattering. We have included similar comparisons between pion- and proton-nucleon effective cross sections as determined from electron-scattering experiments and pion-nucleus and proton-nucleus scattering data.

A study of the nucleus-nucleus total reaction cross section of stable systems at intermediate energies: An application to 12C

Science.gov (United States)

Hu, Liyuan; Song, Yushou; Hou, Yingwei; Liu, Huilan; Li, Hui

2018-07-01

A semi-microscopic analytical expression of the nucleus-nucleus total reaction cross section (σR) was proposed based on the strong absorption model. It is suitable for stable nuclei at intermediate energies. The matter density distributions of nuclei and the nucleon-nucleon total cross section were both considered. Particularly, the Fermi motion effect of the nucleons in a nucleus was also taken into account. The parametrization of σR was applied to the colliding systems including 12C. The experimental data at energies from 30 to 1000 MeV/nucleon were well reproduced, according to which an approach of deriving σR without adjustable parameters was developed. The necessity of considering the Fermi motion effect in the parametrization was discussed.

Distance- and momentum-dependence of modern nucleon-nucleon interactions

International Nuclear Information System (INIS)

Feldmeier, Hans; Neff, Thomas; Weber, Dennis

2015-01-01

A phase-space representation of nuclear interactions, which depends on the distance r vector and relative momentum p vector of the nucleons, is presented. It visualizes in an intuitive way the non-local behavior introduced by cutoffs in momentum space or renormalization procedures that are used to adapt the interaction to low momentum many-body Hilbert spaces, as done in the unitary correlation operator method (UCOM) or with the similarity renormalization group (SRG). It allows to develop intuition about the various interactions and illustrates how the softened interactions reduce the short-range repulsion in favor of non-locality or momentum dependence while keeping the scattering phase shifts invariant. It also reveals that these effective interactions can have undesired complicated momentum dependencies at momenta around and above the Fermi momentum. Properties, similarities, and differences of the Argonne and the N3LO chiral potential, and their UCOM and SRG derivatives are discussed. (author)

The picture of the nuclei disintegration mechanism - from hadron-nucleus and nucleus-nucleus collisions experimental investigations at high energies

International Nuclear Information System (INIS)

Strugalska-Gola, E.; Strugalski, Z.; Chmielowski, W.

1997-01-01

The mechanism of the nuclei disintegration process in collisions of high-energy hadrons with nuclei is revealed experimentally. The disintegration appears as a complicated nuclear process developing in time and space in intranuclear matter, consisting at least of three stages which last together about 10 -24 - 10 -17 s after the impact. At the first stage, which lasts about 10 -24 - 10 -22 s, fast nucleons are densely emitted and the target-nucleus is locally damaged. At the second stage, lasting about 10 -22 - 10 -1 7 s, the damaged and unstable residual target nucleus uses to evaporate light fragments - mainly nucleons, deuterons, tritons, α-particles. At the final stage, the residual target-nucleus uses to split sometimes into two or more nuclear fragments

Why do nucleons cling. [Meson theory

Energy Technology Data Exchange (ETDEWEB)

Kumar, N [Hindu Coll., Delhi (India)

1976-10-01

The nature of the forces which bind nucleons together within the nucleus of an atom have been discussed in detail. The characteristic properties of the nucleons, such as spin, interaction range etc. and the meson theory of nuclear forces are described. The present researches indicate that the force between two nucleons in a many-nucleon system is not very different from the force between two free nucleons. Researches related to the origin of nuclear forces based on the meson theory are now mainly concerned with the role played by the heavier mesons and the two pion exchanges in the middle region around 0.7 fm. (10/sup -13/ cm).

Ab Initio Many-Body Calculations Of Nucleon-Nucleus Scattering

Energy Technology Data Exchange (ETDEWEB)

Quaglioni, S; Navratil, P

2008-12-17

We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and Pauli principle. We outline technical details and present phase shift results for neutron scattering on {sup 3}H, {sup 4}He and {sup 10}Be and proton scattering on {sup 3,4}He, using realistic nucleon-nucleon (NN) potentials. Our A = 4 scattering results are compared to earlier ab initio calculations. We find that the CD-Bonn NN potential in particular provides an excellent description of nucleon-{sup 4}He S-wave phase shifts. We demonstrate that a proper treatment of the coupling to the n-{sup 10}Be continuum is successful in explaining the parity-inverted ground state in {sup 11}Be.

Dissipation in nucleus-nucleus collisions

International Nuclear Information System (INIS)

Santanu Pal

1984-01-01

This paper deals with the mechanism of one- and two-body dissipations in nucleus-nucleus collisions. The average energy transferred to nuclear excitations is calculated using a time-dependent density matrix approach with lowest-order approximations. Considering the nuclei as Fermi gases, and using a gaussian-type NN interaction as the basic perturbation, simplified expressions are obtained for energy dissipations. These expressions are quite instructive to follow a number of interesting aspects of one- and two-body dissipations. It is theoretically observed that the memory time for the two-body dissipation is significantly smaller than that of one-body dissipation. A threshold-type dependence of the transferred energy on the relative velocity between the two nuclei is also observed. This threshold velocity is found to be related with the intrinsic nucleon kinetic energy for two-body dissipation and with the nuclear size for the one-body case. This observation further suggests that the total dissipated energy is shared between the two nuclei approximately in the ratio of their masses. The physical origin of these observations is also explained. Numerical calculations further illustrate some characteristic features of one- and two-body dissipations. (orig.)

Probing nuclear structure with nucleons

International Nuclear Information System (INIS)

Bauge, E.

2007-01-01

The goal of this lecture is to show how nucleon scattering can be used to probe the structure of target nuclei, and how nucleon scattering observables can be interpreted in terms of nuclear structure using microscopic optical potentials. After a brief overview of the specificities of nucleon-nucleus scattering, and a quick reminder on scattering theory, the main part of this lecture is devoted to the construction of optical potentials in which the target nuclei structure information is folded with an effective interaction. Several examples of such microscopic optical model potentials are given. (author)

Nuclear matter studies with density-dependent meson-nucleon coupling constants

International Nuclear Information System (INIS)

Banerjee, M.K.; Tjon, J.A.; Banerjee, M.K.; Tjon, J.A.

1997-01-01

Due to the internal structure of the nucleon, we should expect, in general, that the effective meson nucleon parameters may change in nuclear medium. We study such changes by using a chiral confining model of the nucleon. We use density-dependent masses for all mesons except the pion. Within a Dirac-Brueckner analysis, based on the relativistic covariant structure of the NN amplitude, we show that the effect of such a density dependence in the NN interaction on the saturation properties of nuclear matter, while not large, is quite significant. Due to the density dependence of the g σNN , as predicted by the chiral confining model, we find, in particular, a looping behavior of the binding energy at saturation as a function of the saturation density. A simple model is described, which exhibits looping and which is shown to be mainly caused by the presence of a peak in the density dependence of the medium modified σN coupling constant at low density. The effect of density dependence of the coupling constants and the meson masses tends to improve the results for E/A and density of nuclear matter at saturation. From the present study we see that the relationship between binding energy and saturation density may not be as universal as found in nonrelativistic studies and that more model dependence is exhibited once medium modifications of the basic nuclear interactions are considered. copyright 1997 The American Physical Society

On single nucleon wave functions in nuclei

International Nuclear Information System (INIS)

Talmi, Igal

2011-01-01

The strong and singular interaction between nucleons, makes the nuclear many body theory very complicated. Still, nuclei exhibit simple and regular features which are simply described by the shell model. Wave functions of individual nucleons may be considered just as model wave functions which bear little resemblance to the real ones. There is, however, experimental evidence for the reality of single nucleon wave functions. There is a simple method of constructing such wave functions for valence nucleons. It is shown that this method can be improved by considering the polarization of the core by the valence nucleon. This gives rise to some rearrangement energy which affects the single valence nucleon energy within the nucleus.

Neutrino-nucleus cross-sections: a unified theoretical approach for nucleon knock-out, coherent and incoherent pion production

CERN Document Server

Martini, M; G. Chanfray; Marteau, J

2010-01-01

Neutrino-nucleus cross-sections are needed to interpret neutrino oscillation data, as neutrino detectors involve complex nuclei. We present a theory of neutrino interactions with nuclei aimed at a unified description of the partial cross-sections, namely quasi-elastic and multi-nucleon emission, coherent and incoherent single pion production. We compare our approach to the available neutrino experimental data on carbon. We also discuss the evolution of the neutrino cross-sections with the mass number in view of future precision ex- periments which will use a liquid argon chamber.

Estimation of nuclear destruction in high energy nucleus-nucleus interactions

International Nuclear Information System (INIS)

Uzhinskij, V.V.

1995-01-01

It is assumed that: 1) a projectile particle invokes into target nucleus a cascade of quark-gluon exchanges; 2) the nucleons involved in the cascade are ejected from the nucleus which leads to the nuclear destruction. On these bases a simple model to estimate the nuclear destruction at the fast stage of the interaction is proposed. The allowed region of the model parameters is determined at the proton-emulsion high-energy interaction data analysis: an analysis of gold interactions with nuclei at an energy of 600 MeV/nucleon fixes the parameter values. The distributions on the energy in zero degree calorimeter (T ZDC ) in the interactions of Si+Al, Cu, Pb (14 GeV/nucleon) and Au+Au (10 GeV/nucleon) calculated in the framework of the model and in the cascade-evaporation model (CEM) are presented. The proposed model describes the nuclear destruction at intermediate and high energies better than CEM does. The estimation of the average values of impact parameter and the number of intra-nuclear collisions for Au+Au interactions in the events with different T ZDC is given. 34 refs., 11 figs

New aspects of the atomic nucleus

International Nuclear Information System (INIS)

Wilkinson, D.H.

1987-01-01

We are at last just beginning to identify convincing evidence for what we have long believed, namely that the nucleus is more than the sum of its neutron-proton parts taken pairwise because, for example, a cluster of three nucleons interacts differently from the sum of the interactions of its three pairs; there is an important collectivism in the life of a nucleus even before we ask what its nucleons are doing. (orig./WL)

Microscopic nucleon spectral function for finite nuclei featuring two- and three-nucleon short-range correlations: The model versus ab initio calculations for three-nucleon systems

Science.gov (United States)

Ciofi degli Atti, Claudio; Mezzetti, Chiara Benedetta; Morita, Hiko

2017-04-01

order of magnitude less than the effect of two-nucleon short-range correlations. Conclusions: The convolution model of the spectral function of the three-nucleon systems featuring both two- and three-nucleon short-range correlations and correctly depending upon the ab initio two-nucleon relative and center-of-mass momentum distributions provides in the correlation region a satisfactory approximation of the spectral function in a wide range of momentum and removal energy. The extension of the model to complex nuclei is expected to provide a realistic microscopic parameter-free model of the spectral function, whose properties are therefore governed by the features of realistic two-nucleon interactions and the momentum distributions in a given nucleus.

Dirac phenomenology and hyperon-nucleus interactions

Energy Technology Data Exchange (ETDEWEB)

Mares, J; Jennings, B K [TRIUMF, Vancouver, British Columbia (Canada); Cooper, E D [Fraser Valley Univ. College, Chilliwack, British Columbia (Canada). Dept. of Physics

1993-05-01

We discuss various aspects of hyperon-nucleus interactions in the relativistic mean field theory. First, characteristics of {Lambda}, {Sigma} and {identical_to} hypernuclei, as well as multi strange baryonic objects, are investigated. The spin-orbit splittings and magnetic moments are shown to be very sensitive to the value of the tensor coupling f{omega}y. Second, optical potentials for {Lambda} and {Sigma} scattering off nuclei are developed based on a global nucleon-nucleon Dirac optical potential and SU(3) symmetry. The tensor coupling has a large effect on the predictions for the analyzing power. Third, the Dirac approach is used in the calculations of the non-mesonic decay of {Lambda} hypernuclei. The large discrepancy between the decay rates and data suggests the need for additional meson exchanges. (authors). 62 refs.,7 figs., 6 tabs.

The effect of the new nucleon-nucleus elastic scattering data in LAHET trademark Version 2.8 on neutron displacement cross section calculations

International Nuclear Information System (INIS)

Pitcher, E.J.; Ferguson, P.D.; Russell, G.J.; Prael, R.E.; Madland, D.G.; Court, J.D.; Daemen, L.L.; Wechsler, M.S.

1997-01-01

The latest release of the medium-energy Monte Carlo transport code LAHET includes a new nucleon-nucleus elastic scattering treatment based on a global medium-energy phenomenological optical-model potential. Implementation of this new model in LAHET allows nuclear elastic scattering for neutrons with energies greater than 15 MeV and for protons with energies greater than 50 MeV. Previous investigations on the impact of the new elastic scattering data revealed that the addition of the proton elastic scattering channel can lead to a significant increase in the calculated damage energy under certain conditions. The authors report here results on the impact of the new elastic scattering data on calculated displacement cross sections in various elements for neutrons with energies in the range 16 to 3,160 MeV. Calculated displacement cross sections at 20 MeV in low-mass materials are in better agreement with SPECTER-calculated cross sections

Comparison of different source calculations in two-nucleon channel at large quark mass

Science.gov (United States)

Yamazaki, Takeshi; Ishikawa, Ken-ichi; Kuramashi, Yoshinobu

2018-03-01

We investigate a systematic error coming from higher excited state contributions in the energy shift of light nucleus in the two-nucleon channel by comparing two different source calculations with the exponential and wall sources. Since it is hard to obtain a clear signal of the wall source correlation function in a plateau region, we employ a large quark mass as the pion mass is 0.8 GeV in quenched QCD. We discuss the systematic error in the spin-triplet channel of the two-nucleon system, and the volume dependence of the energy shift.

Projectile fragmentation of a weakly-bound 11Be nucleus at 0.8 GeV/nucleon

International Nuclear Information System (INIS)

Kobayashi, T.

1990-01-01

The projectile fragmentation of a weakly-bound 11 Be projectile has been measured on a carbon target at 0.8 GeV/nucleon. The transverse momentum distribution of 10 Be fragments showed a two-Gaussian structure: a narrow component with σ ∼ 25 MeV/c on top of a wide component with σ ∼ 110 MeV/c. As in the case of 11 Li fragmentation, the narrow momentum distribution indicates a long tail in the neutron density distribution which is consistent with the large nuclear matter radius of the 11 Be nucleus. Neutrons were also measured in coincidence with 10 Be fragments. In contrast to 10 Be fragments, no narrow momentum distribution was observed for coincident neutrons

Similarity of multi-fragmentation of residual nucleus created in nucleus-nucleus interactions at high energies

International Nuclear Information System (INIS)

Abdel-Hafiez, A.; Chernyavski, M.M.; Orlova, G.I.; Gulamov, K.G.; Navotny, V.SH.; Uzhinskii, V.V.

2000-01-01

Experimental data on multi-fragmentation of residual krypton nuclei created in the interactions of the krypton nuclei with photoemulsion nuclei ut energy of 0.9 GeV per nucleon are presented in a comparison with the analogous data on fragmentation of gold residual nuclei at the energy of 10.7 GeV/nucleon. It is shown for the first time that there are two regimes of nuclear multifragmentation: the former is when less than one-half of nucleons of projectile nucleus are knocked out, the later is when more than one-half of nucleons are knocked out. Residual nuclei with closed masses created at different reactions are fragmenting practically simultaneously when more than one-half of nucleons of original nuclei are knocked out. The evidence of existence of a radial flow of the spectator fragment at the decay of residual krypton nuclei is found

S-wave π-nucleus repulsion and dirac phenomenology

International Nuclear Information System (INIS)

Chakravarti, S.; Jennings, B.K.

1993-12-01

A relativistic π-nucleon potential is extended to m* ≠ m to investigate the possibility of generating s-wave π-nucleus repulsion. We find that relativity does indeed generate significant repulsion, the exact amount depending on the details of the calculation. In contradistinction the tp approximation gives very little repulsion. (author). 18 refs., 3 tabs., 2 figs

Nucleon color oscillations in nuclei and the EMC-effect

International Nuclear Information System (INIS)

Smirnov, A.Yu.

1984-01-01

The problem of the EMC-effect is discussed. It is shown that the existence of long-range six-quark clusters in nuclei allows to understand why the nucleon structure function in a nucleus differs from that of a free nucleon

On a calculation of nucleon knock-out cross sections in a collision of relativistic nuclei

International Nuclear Information System (INIS)

Goryachev, B.I.; Lin'kova, N.V.

1985-01-01

It is shown that in the framework of the two-stage model one can obtain knock-out cross sections of the given number of nucleons from the nucleus-target at a certain number of nucleons knocked out from the nucleus-projectile. The first stage is considered as a fast process of nucleon collisions of interacting nuclei which is completed with knock out of one or several nucleons. The second stage-comparatively slow - is related to de-excitation of nuclei-fragments

On the theory of electroproduction of small relative momentum nucleon pairs on atomic nuclei

International Nuclear Information System (INIS)

Nagornyj, S.I.; Inopin, E.V.

1979-01-01

Problems concerning knocking-out of nucleon pairs from atomic nuclei by high-energy electrons are studied. Dependences of cross sections of different processes of the knocking-out on the nucleon relative momentum in a pair are considered. Probabilities of different processes of the knocking-out are compared. A comparison of probabilities of total and three-particle splittings of a 4 He nucleus is performed. On total splitting in the formation of the cross section energy dependence the levels of observable and non-observable subsystems shown to take place. It has been stated that the cross section cannot be increased at the expense of levels of both subsystems simultaneously

Pion production in nucleus--nucleus collisions

International Nuclear Information System (INIS)

Schroeder, L.S.

1975-06-01

Current work on pion production in high-energy nucleus-nucleus collisions is reviewed. The majority of existing data are of the inclusive variety in which a single final state pion is detected. Experimental data are compared and their possible contributions to obtaining new information on nuclear structure is discussed. Various models which attempt to explain the observed single-inclusive-pion spectra either on the basis of a nucleon-nucleus interaction in which Fermi motion is included or on some type of cooperative model are examined. Other areas of interest involving pion production include tests of charge symmetry and pion multiplicities. (9 figures, 1 table) (U.S.)

From nucleons to quarks in nuclei

International Nuclear Information System (INIS)

Laget, J.M.

1984-07-01

Nuclear Physics has now evolved from the study of the many nucleon problem, to the study of the interplay of the degrees of freedom of such a complex system and the internal degrees of freedom of each of its hadronic constituents. Extensive studies of electronuclear reactions have allowed us to disentangle the basic mechanisms of the interaction between two baryons in a nucleus. The pion exchange mechanism, which dominates at large distance has been singled out. The NΔ interaction, which enter the description of the intermediate range part, has been studied. Evidences for effects due to the quark structure of the nucleon have been found. They involve the short distance structure of the nucleus

Characteristics of intermediate-energy nucleons emitted from 50 GeV

International Nuclear Information System (INIS)

Goyal, D.P.; Singh, S.; Arya, N.S.

1984-01-01

The multiplicity and angular distributions of intermediate-energy (grey) nucleons are studied from 50 GeV π - -nucleus data and compared with those available from π - -nucleus and p-nucleus interactions at other energies. The value of is found to be dependent both on the energy as well as on the projectile. The former variation is attributable to kinematics and the latter explainable on the basis of the additive quark model. The angular distribution of grey particles is found to be independent of energy, projectile and target, which supports the view that grey particles are chiefly due to knock-on recoiling protons. The various versions of the cascade model, however, are unable to explain any of the observed features of grey-particle distributions

Global QCD Analysis of the Nucleon Tensor Charge with Lattice QCD Constraints

Science.gov (United States)

Shows, Harvey, III; Melnitchouk, Wally; Sato, Nobuo

2017-09-01

By studying the parton distribution functions (PDFs) of a nucleon, we probe the partonic scale of nature, exploring what it means to be a nucleon. In this study, we are interested in the transversity PDF-the least studied of the three collinear PDFs. By conducting a global analysis on experimental data from semi-inclusive deep inelastic scattering (SIDIS), as well as single-inclusive e+e- annihilation (SIA), we extract the fit parameters needed to describe the transverse moment dependent (TMD) transversity PDF, as well as the Collins fragmentation function. Once the collinear transversity PDF is obtained by integrating the extracted TMD PDF, we wish to resolve discrepancies between lattice QCD calculations and phenomenological extractions of the tensor charge from data. Here we show our results for the transversity distribution and tensor charge. Using our method of iterative Monte Carlo, we now have a more robust understanding of the transversity PDF. With these results we are able to progress in our understanding of TMD PDFs, as well as testify to the efficacy of current lattice QCD calculations. This work is made possible through support from NSF award 1659177 to Old Dominion University.

Jets in high energy nucleon-nucleon collisions

International Nuclear Information System (INIS)

Strugalski, Z.

1982-01-01

From the experimental studies of high-energy hardon-nucleon and nucleon-nucleon collisions, by means of nuclear targets applied as detectors, it follows that particles are produced via intermediate objects created first in a 2 → 2 type endoergic reaction. These objects, called generons, decay in flight into finally observed particles and resonances after their lifetime tausub(g) > or approximately 10 - 22 s. The jet structure of the outcome in nucleon-nucleon collisions is a simple and indispensable consequence of this particle production mechanism. The picture of the jet structure in the collision outcome observed in the CMS of the colliding nucleons depends on the energy of these nUcleons. New particle production scheme is proposed, which can be tested experimentally; corresponding simple relations between characteristics of colliding nucleons and of produced jets are proposed for a testing

Deuteron production in α-nucleus collisions from 200 to 800 MeV per nucleon

International Nuclear Information System (INIS)

Montarou, G.; Alard, J.P.; Augerat, J.; Fraysse, L.; Parizet, M.J.; Babinet, R.; Fodor, Z.; Girard, J.; Gosset, J.; Laspalles, C.; Lemaire, M.C.; L'Hote, D.; Lucas, B.; Poitou, J.; Schimmerling, W.; Terrien, Y.; Brochard, F.; Gorodetzky, P.; Racca, C.; Cugnon, J.; Vandermeulen, J.

1991-01-01

Deuteron spectra at laboratory angles from 30 degree to 90 degree were measured in α+(Pb, Cu, and C) collisions at 800, 600, and 200 MeV/nucleon, and α+(Pb and C) collisions at 400 MeV/nucleon. The coalescence relation between protons and deuterons was examined for the inclusive part of the spectra. The size of the interacting region was evaluated from the observed coalescence coefficients. The rms radius is typically 4--5 fm, depending of the target mass. The proton and deuteron energy spectra corresponding to central collisions were fitted assuming emission from a single source moving with a velocity intermediate between that of the projectile and the target. The extracted ''temperatures'' are independent of the nature of the emitted particle, indicating that the fragments have a common source. The best fits were achieved for 200- and 400-MeV/nucleon reactions. Spectra of deuteron-like pairs, including real deuterons and neutron-proton pairs that may be contained in a larger nuclear cluster, are compared to the prediction of an intranuclear cascade model incorporating a clustering algorithm based on a classical coalescence prescription. Best agreements between experimental and predicted deuteron-like spectra occur for 800- and 600-MeV/nucleon collisions

One-nucleon absorption of slow pions by atomic nuclei and π condensation

International Nuclear Information System (INIS)

Troitskij, M.A.; Koldaev, M.V.; Chekunaev, N.I.

1977-01-01

Solved is a problem of one-nucleon absorption of slow pions by real nuclei. Without ion condensate one-nucleon absorption forbiddenness decreases due to nucleus finiteness, as nucleus finiteness results in nucleon momentum nonconservation. As a result one-nucleon absorption probability differs from a zero and equals the order of 10 -3 . Calculated is one-nucleon absorption probability in nuclear matter as well as in atomic nuclei due to π condensate existence. The condensate part is shown to be considerable in a finite system as well. For heavy nuclei the condensate presence results in this probability increase about 100 times. Experiments on one-nucleon absorption of slow pions may be critical to elucidate a question of π condensate presence in nuclear systems. In conclusion experimental data available on pion absorption are discussed and it is paid attention to the necessity of carrying out further experiments

Effective pion--nucleon interaction in nuclear matter

International Nuclear Information System (INIS)

Celenza, L.S.; Liu, L.C.; Nutt, W.; Shakin, C.M.

1976-01-01

We discuss the modification of the interaction between a pion and a nucleon in the presence of an infinite medium of nucleons (nuclear matter). The theory presented here is covariant and is relevant to the calculation of the pion--nucleus optical potential. The specific effects considered are the modifications of the nucleon propagator due to the Pauli principle and the modification of the pion and nucleon propagators due to collisions with nucleons of the medium. We also discuss in detail the pion self-energy in the medium, paying close attention to off-shell effects. These latter effects are particularly important because of the rapid variation with energy of the fundamental pion--nucleon interaction. Numerical results are presented, the main feature being the appearance of a significant damping width for the (3, 3) resonance

A dependence of quasielastic charged-current neutrino-nucleus cross sections

Science.gov (United States)

Van Dessel, N.; Jachowicz, N.; González-Jiménez, R.; Pandey, V.; Van Cuyck, T.

2018-04-01

Background: 12C has been and is still widely used in neutrino-nucleus scattering and oscillation experiments. More recently, 40Ar has emerged as an important nuclear target for current and future experiments. Liquid argon time projection chambers (LArTPCs) possess various advantages in measuring electroweak neutrino-nucleus cross sections. Concurrent theoretical research is an evident necessity. Purpose: 40Ar is larger than 12C , and one expects nuclear effects to play a bigger role in reactions. We present inclusive differential and total cross section results for charged-current neutrino scattering on 40Ar and perform a comparison with 12C , 16O , and 56Fe targets, to find out about the A -dependent behavior of model predictions. Method: Our model starts off with a Hartree-Fock description of the nucleus, with the nucleons interacting through a mean field generated by an effective Skyrme force. Long-range correlations are introduced by means of a continuum random phase approximation approach. Further methods to improve the accuracy of model predictions are also incorporated in the calculations. Results: We present calculations for 12C , 16O , 40Ar , and 56Fe , showcasing differential cross sections over a broad range of kinematic values in the quasielastic regime. We furthermore show flux-folded results for 40Ar and we discuss the differences between nuclear responses. Conclusions: At low incoming energies and forward scattering we identify an enhancement in the 40Ar cross section compared to 12C , as well as in the high ω (low Tμ) region across the entire studied Eν range. The contribution to the folded cross section of the reaction strength at values of ω lower than 50 MeV for forward scattering is sizable.

Nucleon-nucleus scattering: a microscopic nonrelativistic approach

International Nuclear Information System (INIS)

Amos, K.; Dortmans, H.V.; Raynal, J.

1998-01-01

The authors are reviewing the nucleon based microscopic theory of nucleon-nucleus (NA) scattering and its applications taking in consideration the developments that have occurred within the last decade. The review comprises 12 Chapters. The first is a brief outline of some formal aspects of the nuclear optical potential and the scattering theory by which it is related to NN scattering amplitudes, t matrices and g matrices. Then follows a presentation of the momentum space NA optical potential formed by the folding of NN t- and g matrices with nuclear densities. Applications are discussed with the examples taken from the works of Elster et al. and of Arellano et al. A folding model defining the optical potential in coordinate space is then considered. That model presupposes an effective NN interaction to be comprised of density and energy dependent central, tensor, and two-body spin-orbit terms. Such effective interactions are basic for the computer codes DWBA91 and DWBA98 that are the current technology to calculate and use microscopic non-local coordinate space optical potentials. Thus in Chapter 4, we present the helicity formalism, the multipole expansions of the effective interactions, and the particle-hole matrix elements that underlay calculations made with those programs. A key feature of both the momentum and coordinate space formulations of the NA optical potentials are the NN t- and g matrices. Details of those are given in Chapter 5 and 6 respectively. Therein the on- and off-shell properties of the t- and g matrices from realistic bosom exchange potentials, as well as from potentials determined by inversion of phase shift data, are discussed. To form the coordinate space NA optical potentials requites the effective interaction in coordinate space. Thus a parametrisation scheme is needed to specify such front t- and g matrices. A scheme that has proven useful is then discussed. In fact, the effective interactions that result, when folded with nuclear

Interesting correlations among various parameters of charged secondaries in nucleus - nucleus interactions at 4.5 A GeV

International Nuclear Information System (INIS)

Khan, M. Saleem; Shukla, Praveen Prakash; Khushnood, H.

2015-01-01

The study of the characteristic of charged secondaries was the aim of most of the experiments on high energy nucleon-nucleon and nucleus-nucleus collisions. Investigation are carried out on the produced secondary charged particles with a common belief that these particles are more informative about the collisional dynamics and thus, could be effective in revealing the underlying physics of high energy relativistic interactions. So for understanding the mechanism of multiparticle production in high energy hadron-nucleus collisions, the correlations amongst the secondary charged particles are studied. Several workers have attempted to study the multiplicity correlations over widely different incident energies with different projectiles. The AALMT collaboration have also studied the multiplicity correlations in 200 GeV proton-nucleus collisions

Exact multiple scattering theory of two-nucleus collisions including the Pauli principle

International Nuclear Information System (INIS)

Gurvitz, S.A.

1981-01-01

Exact equations for two-nucleus scattering are derived in which the effects of the Pauli principle are fully included. Our method exploits a modified equation for the scattering of two identical nucleons, which is obtained at the beginning. Considering proton-nucleus scattering we found that the resulting amplitude has two components, one resembling a multiple scattering series for distinguishable particles, and the other a distorted (A-1) nucleon cluster exchange. For elastic pA scattering the multiple scattering amplitude is found in the form of an optical potential expansion. We show that the Kerman-McManus-Thaler theory of the optical potential could be easily modified to include the effects of antisymmetrization of the projectile with the target nucleons. Nucleus-nucleus scattering is studied first for distinguishable target and beam nucleus. Afterwards the Pauli principle is included, where only the case of deuteron-nucleus scattering is discussed in detail. The resulting amplitude has four components. Two of them correspond to modified multiple scattering expansions and the others are distorted (A-1)- and (A-2)- nucleon cluster exchange. The result for d-A scattering is extended to the general case of nucleus-nucleus scattering. The equations are simple to use and as such constitute an improvement over existing schemes

Are ''anomalons'' a bag ful'o colorful nucleons

International Nuclear Information System (INIS)

Kruse, F.; Noack, C.C.

1983-01-01

One of the more intriguing explanations of the possible existence of ''anomalons'' (if they do exist) would seem to be in terms of internal color excitations of nuclei. While it follows from confinement in QCD that isolated nuclei (as well as isolated nucleons) must be in color singlet states, the same is not necessarily so for nucleons bound together in a small region of space, viz. a nucleus. Thus one can envisage a nucleus in a color-excited state as composed of localized 3q-systems (i.e. nucleons) which, however, are not all color singlets. We have investigated a particularly simple example of such a model which retains as many of the features of ''normal'' nuclei as possible, and at the same time stays close to the physical picture of the M.I.T. bag model. We call this a ''nuclear bag.''

Effect of Δ-isobar excitation on spin-dependent observables of elastic nucleon-deuteron scattering

International Nuclear Information System (INIS)

Nemoto, S.; Oryu, S.; Chmielewski, K.; Sauer, P.U.

2000-01-01

Δ-isobar excitation in the nuclear medium yields an effective three-nucleon force. A coupled-channel formulation with Δ-isobar excitation developed previously is used. The three-particle scattering equations are solved by a separable expansion of the two-baryon transition matrix for elastic nucleon-deuteron scattering. The effect of Δ-isobar excitation on the spin-dependent observables is studied at energies above 50 MeV nucleon lab energy. (author)

The interaction of LAMBDA and nucleon in the LAMBDA hypernuclei

International Nuclear Information System (INIS)

Jin Xingnan

1988-01-01

The interaction of lambda particle and nucleon is discussed from phenomenological point of view. The effective interactions between the lambda particle and the nucleon in the hypernuclei are also presented in this paper. The structure effect of the hypernuclei will make influence to the effective interaction between the lambda particle and the nucleon in the hypernucei. The spin-orbital coupling of lambda particle in the lambda hypernucleus is much smaller than the spin-orbital coupling of nucleon in nucleus

A new form for the nucleon-nucleon potential

International Nuclear Information System (INIS)

Agarwal, B.K.

1976-01-01

The form of the internucleon force is considered. It is assumed that the nucleon-nucleon potential depends, in general, both on the distance ν and the angle theta. It is also assumed that the potential V(ν,ω) admits an analytic continuation into the complex ω-plane so that when ω=costheta is real it denotes the direction in which the potential is being determined. The analysis leads to a new parametryzation of the nucleon-nucleon potential

Inclusive proton spectra and total reaction cross sections for proton-nucleus scattering at 800 MeV

International Nuclear Information System (INIS)

McGill, J.A.

1981-08-01

Current applications of multiple scattering theory to describe the elastic scattering of medium energy protons from nuclei have been shown to be quite successful in reproducing the experimental cross sections. These calculations use the impulse approximation, wherein the scattering from individual nucleons in the nucleus is described by the scattering amplitude for a free nucleon. Such an approximation restricts the inelastic channels to those initiated by nucleon-nucleon scattering. As a first step in determining the nature of p + nucleus scattering at 800 MeV, both total reaction cross sections and (p,p') inclusive cross sections were measured and compared to the free p + p cross sections for hydrogen, deuterium, calcium 40, carbon 12, and lead 208. It is concluded that as much as 85% of all reactions in a nucleus proceed from interactions with a single nucleon in the nucleus, and that the impulse approximation is a good starting point for a microscopic description of p + nucleus interactions at 800 MeV

Multiplicity of secondaries in hadron-nucleus collisions and constituent quark rescattering

International Nuclear Information System (INIS)

Shabelsky, Yu.M.; Shekhter, V.M.

1980-01-01

A ratio of the relativistic secondary multiplicities for hadron-nucleus and hadron-nucleon interactions, Rsub(s)(hA), is considered in the central region and a part of the target nucleus fragmentation region. The multiplicities are obtained from the experimental average numbers of relativistic charged or negative particles by subtraction of the projectile fragment numbers estimated theoretically. Two hypotheses on the A dependence of the secondary multiplicity in a constituent quark interaction with a nucleus are discussed. An assumption that this multiplicity is independent of A leads to Rsub(s)(hA) = antiνsub(hA)/antiνsub(qA). An alternative assumption that the qA multiplicity increases with A due to quark rescattering from several nucleons gives Rsub(s)(hA) = antiνsub(hA). Comparison with experiment in the former case requires a great number of positively charged hadrons, probably protons, emitted from the nucleus. This number must rise significantly with both A and incident energy. The latter hypothesis is consistent with all data on as well as in pA collisions but disagrees by approximately 20% with in π - A interactions. (author)

High-energy elastic and quasi-elastic deuteron-nucleus scattering

International Nuclear Information System (INIS)

Tekou, Amouzou

1974-01-01

A study is made of deuteron-nucleus elastic and quasi-elastic scattering and the connection between the opaque nucleus model and the Glauber model is pointed out. The contributions to different cross-sections of the collisions in which the nucleus, excited by one of the nucleons of the deuteron, is brought back to the ground state by the other nucleon is analysed. Coherent deuteron disintegration is found to be highly improbable when the target nucleus is heavy and incoherent disintegration accounts for nearly all the deuteron disintegration. Thus a correct comparison between theoretical and experimental data on proton stripping must take the incoherent deuteron disintegration into consideration

Projective multifragments break-up and the electromagnetic field effect of target nucleus

International Nuclear Information System (INIS)

Nabil Yasin, M.

1994-12-01

This work presents a special type of interactions produced in emulsion targets exposed to different incident beams of light ions at a few GeV per nucleon. The events characterised by multifragment break-up of the projectile nucleus which are produced via peripheral collisions or due to the effect of the Coulomb field of the target nucleus have been selected. The size of impact parameter must be considered for determining the type of the interaction. The results are compared with other collected data at energies (up to 200 GeV/nucleon). The dependence of electromagnetic dissociation cross section on the incident projectile energy is investigated. Also, a comparison of the experimental data with the assumed virtual photon spectrum using Weizsaecker-Williams (WW) method is made. (author). 34 refs, 3 figs, 4 tabs

Energy-dependent microscopic optical potential for scattering of nucleons on light nuclei

Energy Technology Data Exchange (ETDEWEB)

Farag, M.Y.H.; Esmael, E.H. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Maridi, H.M. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Taiz University, Physics Department, Faculty of Applied Science, Taiz (Yemen)

2014-06-15

We present an energy-dependent microscopic optical model potential for elastic scattering of nucleons on light nuclei. The single-folding model is used for the real part of the optical potential (OP), while the imaginary part is derived within the high-energy approximation theory. The energy dependence of the OP is determined from the parameterization of the volume integrals those calculated from the best-fit OP that fit the experimental data of the cross sections and analyzing powers. This energy-dependent OP is successfully applied to analyze the proton elastic scattering of {sup 4,6,i8}He, {sup 6,7}Li, and {sup 9,10}Be nuclei at low and intermediate incident energies up to 200MeV/nucleon. (orig.)

Universality of many-body two-nucleon momentum distributions: Correlated nucleon spectral function of complex nuclei

Science.gov (United States)

Ciofi degli Atti, Claudio; Morita, Hiko

2017-12-01

Background: The nuclear spectral function is a fundamental quantity that describes the mean-field and short-range correlation dynamics of nucleons embedded in the nuclear medium; its knowledge is a prerequisite for the interpretation of various electroweak scattering processes off nuclear targets aimed at providing fundamental information on strong and weak interactions. Whereas in the case of the three-nucleon and, partly, the four-nucleon systems, the spectral function can be calculated ab initio within a nonrelativistic many-body Schroedinger approach, in the case of complex nuclei only models of the correlated, high-momentum part of the spectral function are available so far. Purpose: The purpose of this paper is to present a new approach such that the spectral function for a specific nucleus can be obtained from a reliable many-body calculation based upon realistic nucleon-nucleon interactions, thus avoiding approximations leading to adjustable parameters. Methods: The expectation value of the nuclear many-body Hamiltonian, containing realistic nucleon-nucleon interaction of the Argonne family, is evaluated variationally by a normalization-conserving linked-cluster expansion and the resulting many-body correlated wave functions are used to calculate the one-nucleon and the two-nucleon momentum distributions; by analyzing the high-momentum behavior of the latter, the spectral function can be expressed in terms of a transparent convolution formula involving the relative and center-of-mass (c.m.) momentum distributions in specific regions of removal energy E and momentum k . Results: It is found that as a consequence of the factorization of the many-body wave functions at short internucleon separations, the high-momentum behavior of the two-nucleon momentum distributions in A =3 ,4 ,12 ,16 ,40 nuclei factorizes, at proper values of the relative and c.m. momenta, into the c.m. and relative momentum distributions, with the latter exhibiting a universal A

Invariant potential for elastic pion--nucleus scattering

International Nuclear Information System (INIS)

Cammarata, J.B.; Banerjee, M.K.

1976-01-01

From the Wick-Dyson expansion of the exact propagator of a pion in the presence of a nucleus, an invariant potential for crossing symmetric elastic pion-nucleus scattering is obtained in terms of a series of pion-nucleon diagrams. The Chew-Low theory is used to develop a model in which the most important class of diagrams is effectively summed. Included in this model is the exclusion principle restriction on the pion-bound nucleon interaction, the effects of the binding of nucleons, a kinematic transformation of energy from the lab to the πN center of mass frame, and the Fermi motion and recoil of the target nucleons. From a numerical study of the effects of these processes on the π- 12 C total cross section, the relative importance of each is determined. Other processes contributing to the elastic scattering of pions not included in the present model are also discussed

Classical gluon production amplitude for nucleus-nucleus collisions:First saturation correction in the projectile

International Nuclear Information System (INIS)

Chirilli, Giovanni A.; Kovchegov, Yuri V.; Wertepny, Douglas E.

2015-01-01

We calculate the classical single-gluon production amplitude in nucleus-nucleus collisions including the first saturation correction in one of the nuclei (the projectile) while keeping multiple-rescattering (saturation) corrections to all orders in the other nucleus (the target). In our approximation only two nucleons interact in the projectile nucleus: the single-gluon production amplitude we calculate is order-g"3 and is leading-order in the atomic number of the projectile, while resumming all order-one saturation corrections in the target nucleus. Our result is the first step towards obtaining an analytic expression for the first projectile saturation correction to the gluon production cross section in nucleus-nucleus collisions.

Nucleus--nucleus potential

International Nuclear Information System (INIS)

Jaqaman, H.R.

1977-01-01

The nucleus--nucleus interaction is studied within the framework of the generator coordinate method that permits an easy incorporation of the full effects of antisymmetrization. It is found that the interaction, as far as the elastic scattering problem is concerned, can be described by a simple effective potential that is equivalent to the original many-body (and hence non-local) problem. The potential is obtained by dividing the wavefunction into a long-range part and a short-range part and requiring the former to satisfy a Schroedinger equation. This enables avoiding dealing with the troublesome short-range part of the wavefunction and provides a direct link with the optical model so that the potential obtained here is equivalent to the real part of the optical potential (the imaginary part is not investigated). The effective potential is found to consist of three parts: an interaction term between the nucleons belonging to different nuclei, a kinetic energy term due to the change in the intrinsic kinetic energy of the system as a result of the antisymmetrization, and finally an l-dependent part. The kinetic energy term is found to be very repulsive and effectively gives a hard core, and is calculated for the α--α and 16 O-- 16 O cases. The full potential is calculated for the α--α case for the S, D, and G partial waves and then used to calculate the corresponding phase shifts that are then compared with experimental results and other microscopic calculations. Finally, some recent results and analyses of fusion and deep inelastic reactions are reviewed that seem to indicate the presence of a hard core in the nucleus--nucleus potential. Such a hard core is present in the potential obtained in the sudden approximation

Conflicting coupling of unpaired nucleons in odd-odd nuclei

International Nuclear Information System (INIS)

Volkov, D.A.; Levon, A.I.

1990-01-01

Phenomenological approach is described, using it, energy spectra of odd-odd nucleus collective bands based on conflicting state of unpaired nucleons can be calculated. It is ascertained that in a conflicting bond unpaired nucleon acts as a spectator, i.e. energy spectra of collective bands in odd-odd nuclei are similar to the spectra of collective bands in heighbouring odd nuclei, which are based on the state of a strongly bound nucleon is included in the conflicting configuration

Coherent generation of mesons in nucleon-nucleon interactions

CERN Document Server

Takibaev, Z S; Zaitsev, K G

1974-01-01

The authors have at an experiment conducted at CERN searched for events of 0 four-prong type which satisfy coherent pion production. The 2-meter hydrogen bubble chamber at CERN was bombarded by 19.07 GeV protons. The cross-section for four final state particle events was 13.04 mb. the cross-section for the process pp to pp pi /sup +/ pi /sup -/ was 1.1 mb and the cross section for coherent pion production was found to vary according to the criteria used between 0.044 mb. and 0.2 mb. Some theoretical work is given using the Glauber formalism in which it is assumed that the nucleon behaves like a nucleus and contains sub-particles. From the theory and data an upper limit of 10 is put on the number of subparticles in the nucleon. (9 refs).

EMC-effect and QCD evolution of the threequark nucleon picture

International Nuclear Information System (INIS)

Grigoryan, L.A.; Shakhbazyan, V.A.

1985-01-01

It is shown that the EMC-effect can be explained in the framework of the QCD evolution of the threequark nucleon picture. In comparing with the experimental data it is found that the effective radius of nucleon, which is in the iron nucleus, increases by 10% as compared with the free nucleon case. A comparison with experimental data in the region of 0.25 ≤ x ≤ 0.65 is made

In medium modification of nucleon electromagnetic properties

International Nuclear Information System (INIS)

Khanna, F.; Rakhimov, A.; Yakhsiev, U.

1997-01-01

Since nucleons are composite objects, their internal structure is expected to be changed by nuclear environment. A Skyrme like Lagrangian is proposed to consider such effects, namely the modification of electromagnetic (EM) properties of the nucleon. The static properties and EM form factors were obtained. It was shown that the charge radius of the nucleon increased in medium and the mass and axial coupling constant are reduced. The enhancement of magnetic moment of proton is smaller than that obtained in non-topological soliton model.Obtained results may be useful in electron nucleus scattering analysis.(A.A.D.)

Exotic atoms and the kaon-nucleon interaction

International Nuclear Information System (INIS)

Batty, C.J.

1989-12-01

Recent progress in the study of p-bar-p and p-bar-nucleus atoms is briefly reviewed before moving on to a discussion of the kaon-nucleon interaction at low energies. The need for new definitive X-ray measurements for K - p atoms is emphasised. Finally some comments are made about K-bar-nucleus and Σ - , Ξ - and Ω - atoms. (author)

Percolation picture of disintegration of nuclei in the proton-nucleus interaction

International Nuclear Information System (INIS)

Botvina, A.S.; Lanin, L.V.

1992-01-01

Breakup of nuclei into fragments in the proton-nucleus interaction is studied. It is assumed that breakup occurs in two stages. During the first stage the incident particle interacts with individual nucleons of the nucleus, and high-energy reaction products are emitted from the nucleus. This stage is described by means of the intranuclear-cascade model. During the second stage some of the nuclei, whose excitation energy is high, or whose density is very inhomogeneous, break up. This breakup is described by means of a percolation model which takes into account the spatial distribution of nucleons in the nucleus and which generalizes the percolation description of the 'liquid-gas' phase transition for finite nuclei. Features of this breakup mechanism are studied. The analysis of the experimental data indicates that it is not sufficient to consider percolation only in the coordinate space, and that the momentum distribution of the nucleons in the nucleus must be taken into account

Charge dependence of the pion-nucleon coupling constant

Directory of Open Access Journals (Sweden)

V. A. Babenko

2015-07-01

Full Text Available On the basis of the Yukawa potential we study the pion-nucleon coupling constants for the neutral and charged pions assuming that nuclear forces at low energies are mainly determined by the exchange of virtual pions. We obtain the charged pseudovector pion-nucleon coupling constant f2π± = 0.0804(7 by making the use of experimental low-energy scattering parameters for the singlet pp- and np-scattering, and also by use of the neutral pseudovector pion-nucleon coupling constant f2π0 = 0.0749(7. Corresponding value of the charged pseudoscalar pion-nucleon coupling constant g2π0 / 4π = 14.55(13 is also determined. This calculated value of the charged pseudoscalar pion-nucleon coupling constant is in fully agreement with the experimental constant g2π0 / 4π = 14.52(26 obtained by the Uppsala Neutron Research Group. Our results show considerable charge splitting of the pion-nucleon coupling constant.

Coupled channels Marchenko inversion for nucleon-nucleon potentials

International Nuclear Information System (INIS)

Kohlhoff, H.; Geramb, H.V. von

1994-01-01

Marchenko inversion is used to determine local energy independent but channel dependent potential matrices from optimum sets of experimental phase shifts. 3 SD 1 and 3 PF 2 channels of nucleon-nucleon systems contain in their off-diagonal potential matrices explicitly the tensor force for T = 0 and 1 isospin. We obtain, together with single channels, complete sets of quantitative nucleon-nucleon potential results which are ready for application in nuclear structure and reaction analyses. The historic coupled channels inversion result of Newton and Fulton is revisited. (orig.)

Problem of determination of the elementary hardon-nucleon interaction amplitude from Glauber-theory analysis of elastic hardon-nucleus scattering and self-consistent FFS nuclear densities

International Nuclear Information System (INIS)

Saperstein, E.E.

1992-01-01

The influence of the detailed behavior of the nuclear densities on the Glauber-theory description of hadron-nucleus scattering is discussed in connection with the problem of determination of elementary hadron-nucleon amplitudes from such analysis. Arguments are given in favor of using the self-consistent FFS nuclear densities for this purpose. 20 refs., 6 figs

Global fits of the dark matter-nucleon effective interactions

International Nuclear Information System (INIS)

Catena, Riccardo; Gondolo, Paolo

2014-01-01

The effective theory of isoscalar dark matter-nucleon interactions mediated by heavy spin-one or spin-zero particles depends on 10 coupling constants besides the dark matter particle mass. Here we compare this 11-dimensional effective theory to current observations in a comprehensive statistical analysis of several direct detection experiments, including the recent LUX, SuperCDMS and CDMSlite results. From a multidimensional scan with about 3 million likelihood evaluations, we extract the marginalized posterior probability density functions (a Bayesian approach) and the profile likelihoods (a frequentist approach), as well as the associated credible regions and confidence levels, for each coupling constant vs dark matter mass and for each pair of coupling constants. We compare the Bayesian and frequentist approach in the light of the currently limited amount of data. We find that current direct detection data contain sufficient information to simultaneously constrain not only the familiar spin-independent and spin-dependent interactions, but also the remaining velocity and momentum dependent couplings predicted by the dark matter-nucleon effective theory. For current experiments associated with a null result, we find strong correlations between some pairs of coupling constants. For experiments that claim a signal (i.e., CoGeNT and DAMA), we find that pairs of coupling constants produce degenerate results

Multiplicity, momentum and angular characteristics of π- mesons for pC, dC, αC and CC interactions at 4.2 Gev/c per nucleon

International Nuclear Information System (INIS)

Agakishiev, N.N.; Akhababyan, N.; Armutlijsky, D.

1984-01-01

Multiplicity, momentum and angular characteristics of π - mesons produced in interactions of light nuclei (p, d, a, C) with carbon at a momentum of 4.2 GeV/c per nucleon are investigated. It is shown that the average multiplicity of π - mesons, , increases proportionally to the number of nucleons of the projectile nucleus which participate in the interaction with a carbon nucleus. A linear dependence of the dispersion of the π - meson multiplicity distribution on is observed. The shape of the π - meson distributions over Psub(lab.), THETAsub(lab.), Psub(tr) and ysub(lab.) weakly depends on the atomic weight of the projectile. The experimental data can be satisfactorily described by the Dubna version of the cascade model and by the multiple scattering model

Nucleon in nuclei from quasi-elastic electron scattering

International Nuclear Information System (INIS)

Gerard, A.

1987-04-01

One challenging problem in modern nuclear physics is to understand how the internal structure of the nucleon interferes with the dynamics of nucleons in a nucleus. The purpose of this paper is to review the present status of data in quasi-elastic electron scattering, to connect them with recent theoretical developments and to outline some future directions of research not accessible to present electron facilities

Spin symmetry in the Dirac sea derived from the bare nucleon-nucleon interaction

Science.gov (United States)

Shen, Shihang; Liang, Haozhao; Meng, Jie; Ring, Peter; Zhang, Shuangquan

2018-06-01

The spin symmetry in the Dirac sea has been investigated with relativistic Brueckner-Hartree-Fock theory using the bare nucleon-nucleon interaction. Taking the nucleus 16O as an example and comparing the theoretical results with the data, the definition of the single-particle potential in the Dirac sea is studied in detail. It is found that if the single-particle states in the Dirac sea are treated as occupied states, the ground state properties are in better agreement with experimental data. Moreover, in this case, the spin symmetry in the Dirac sea is better conserved and it is more consistent with the findings using phenomenological relativistic density functionals.

Nucleon-nucleon momentum correlation function for light nuclei

International Nuclear Information System (INIS)

Ma, Y.G.; Cai, X.Z.; Chen, J.G.; Fang, D.Q.; Guo, W.; Liu, G.H.; Ma, C.W.; Ma, E.J.; Shen, W.Q.; Shi, Y.; Su, Q.M.; Tian, W.D.; Wang, H.W.; Wang, K.; Wei, Y.B.; Yan, T.Z.

2007-01-01

Nucleon-nucleon momentum correlation function have been presented for nuclear reactions with neutron-rich or proton-rich projectiles using a nuclear transport theory, namely Isospin-Dependent Quantum Molecular Dynamics model. The relationship between the binding energy of projectiles and the strength of proton-neutron correlation function at small relative momentum has been explored, while proton-proton correlation function shows its sensitivity to the proton density distribution. Those results show that nucleon-nucleon correlation function is useful to reflect some features of the neutron- or proton-halo nuclei and therefore provide a potential tool for the studies of radioactive beam physics

Nucleon-nucleon correlations and the Coulomb Displacement Energy

International Nuclear Information System (INIS)

Van Neck, D.; Waroquier, M.; Heyde, K.

1997-01-01

Coulomb Displacement Energies (CDE) are accurately known for a wide range of nuclear masses. Assuming isospin independence in the nuclear Hamiltonian, the CDE can in first instance be interpreted as the Coulomb interaction energy between the density of the excess neutrons and the proton charge density in the parent nucleus. However, when using reasonable mean-field models for the proton and neutron density one underestimates the CDE by about 8% on average. This discrepancy is known as the Nolen-Schiffer anomaly, and various explanations have been put forward in the past. In this work the role of nucleon-nucleon correlations are re-examined. Calculations for the pair density functions in various nuclei are presented. Preliminary results suggest that the modifications to the mean-field pair density functions cause an enhancement of the CDE in the order of 4%, which is rather A-independent. (author)

First Monte Carlo Global Analysis of Nucleon Transversity with Lattice QCD Constraints

Science.gov (United States)

Lin, H.-W.; Melnitchouk, W.; Prokudin, A.; Sato, N.; Shows, H.; Jefferson Lab Angular Momentum JAM Collaboration

2018-04-01

We report on the first global QCD analysis of the quark transversity distributions in the nucleon from semi-inclusive deep-inelastic scattering (SIDIS), using a new Monte Carlo method based on nested sampling and constraints on the isovector tensor charge gT from lattice QCD. A simultaneous fit to the available SIDIS Collins asymmetry data is compatible with gT values extracted from a comprehensive reanalysis of existing lattice simulations, in contrast to previous analyses, which found significantly smaller gT values. The contributions to the nucleon tensor charge from u and d quarks are found to be δ u =0.3 (2 ) and δ d =-0.7 (2 ) at a scale Q2=2 GeV2.

Final stage of high energy hadron-nucleus nuclear collision reactions

International Nuclear Information System (INIS)

Strugal'ski, Z.; Jedrzejec, H.; Strugalska-Gola, E.; Mulas, E.

1996-01-01

The final or 'slow' stage of the hadron-nucleus collision reactions at high energy is considered on the basis of the collision mechanism prompted experimentally. The transmutation process of the damaged target nucleus into nucleons and stable nuclear fragments is discussed. Relations between intensities or multiplicities n p of the emitted fast protons and the mean intensities or multiplicities b > of the evaporated nucleons and nuclear fragments are presented. 14 refs

The Mathematical Model High Energy Collisions Process Hadron-Nucleus

International Nuclear Information System (INIS)

Wojciechowski, A.; Strugalska-Gola, E.; Strugalski, Z.

2002-01-01

During the passage high energy hadron by the heavy nucleus emitted are nucleons and many other particles from which most more group are nucleons and mesons π + π - π 0 . in this work we will present the mathematical model which is a simplified description of basic processes in the interior of the nucleus during passing of the hadron by the nucleus. Result of calculations we will compare with experimental results. Experimental data are based on photographs of 180 litre xenon bubble chambers (180 1 KKP) of Institute of Theoretical and Experimental Physics in Moscow (ITEF, Moscow) irradiated with the beam of mesons π - with momentum 3.5 GeV/c. (author)

Contribution of nucleonic degrees of freedom to the EMC effect

International Nuclear Information System (INIS)

Anisovich, V.V.; Sarantsev, A.V.; Starodubskii, V.E.

1987-01-01

The dispersion-integration method has been used to calculate the contribution of nucleonic degrees of freedom to the EMC effect. The structure of the amplitude of deep inelastic scattering is discussed for a nucleus with spin one half. The question of the functional form of the structure function of a nucleon off the mass shell is discussed

The nucleon-air nuclei interaction probability law with rising cross-sections

International Nuclear Information System (INIS)

Portella, H.M.; Oliveira Castro, F.M. de.

1988-01-01

The negative-binomial interaction probability law for nucleon of atmosphere is obtained as a consequence of the respective diffUsion equation. The mean-free path of the nucleon-nucleus interaction rises with the energy of the incident nucleon in the form 1/λ N (E) = (1+aln(E/E 0 ))/λ 0 N , E 0 =1 TeV. In the case of lambda N = constant the distribution law is poissonian. (author) [pt

Theories of the eta-meson-nucleus interaction

International Nuclear Information System (INIS)

Liu, L.C.

1994-01-01

It is sown that the pion-nucleon elastic scattering, eta-nucleon scattering length and the cross sections for pion-induced eta production on a nucleon satisfy a set of consistency relations. These relations are used to examine the ηN scattering lengths given by the various models. The nature of the threshold ηN interaction is discussed and recent advancements in ηN interaction is discussed and recent advancements in η-nucleus reaction theory are reviewed

Low-energy antikaon nucleon and nucleus interaction studies

Science.gov (United States)

Marton, Johann; Leannis Collaboration

2011-04-01

The antikaon (K-) interaction on nucleons and nuclei at low energy is neither simple nor well understood. Kaonic hydrogen is a very interesting case where the strong interaction of K- with the proton leads to an energy shift and a broadening of the 1s ground state. These two observables can be precisely studied with x-ray spectroscopy. The behavior at threshold is influenced strongly by the elusive Lambda(1405) resonance. In Europe the DAFNE electron-positron collider at Laboratori Nazionali di Frascati (LNF) provides an unique source of monoenergetic kaons emitted in the Phi meson decay. Recently the experiment SIDDHARTA on kaonic hydrogen and helium isotopes was successfully performed at LNF. A European network LEANNIS with an outreach to J-PARC in Japan was set up which is promoting the research on the antikaon interactions with nucleons and nuclei. This talk will give an overview of LEANNIS research tasks, the present status and an outlook to future perspectives. Financial support by the EU project HadronPhysics2 is gratefully acknowledged.

The swelling of nucleons in nuclei and the Roper resonance

International Nuclear Information System (INIS)

Desplanques, B.

1988-01-01

Conditions where some swelling of the nucleon occurs, and, in particular the relation of this effect with the attractive character of the force acting on it, are studied. It is found that short range repulsive correlations can turn the swelling into a shrinking, in spite of a globally attractive interaction, whereas repulsive velocity dependent forces can lead to some swelling. The role of the Roper resonance in this nucleon change of size is considered in some detail

On the nucleon renormalization in many nucleon problems due to pionic degrees of freedom

International Nuclear Information System (INIS)

Sauer, P.U.; Sawicki, M.; Furui, Sadataka.

1985-01-01

Conceptual problems of unified two-nucleon force models are discussed. The force models are based on the pion-nucleon vertex and attempt a description of the nucleon-nucleon interaction below and above pion threshold. The conceptual problems arise from the nucleon renormalization due to pionic degrees of freedom. Keeping channels with a single pion only no renormalization procedure can be given which is consistent in the one-nucleon and in the many-nucleon systems. The medium dependence of the one-pion exchange potential is illustrated. (author)

Elastic scattering of protons on 8Li nucleus in inverse kinematics

International Nuclear Information System (INIS)

Zhusupov, M.A.; Ibraeva, E.T.; Sanfirova, A.B.; Imambekov, O.

2002-01-01

In the present paper the proton elastic scattering on 8 Li in inverse kinematics is studies. The inverse kinematics means that a beam of radioactive nuclei is scattered on a stable hydrogen target. Proton as a target has an advantage during the interaction since it is stable and mechanism of proton-nucleus scattering is quite simple. 8 Li nucleus is considered in the three-body αtn-model with realistic potential of inter-cluster interactions. The wave function of this nucleus is calculated in the work where it was shown that such model well describes the main spectroscopic characteristics of the nucleus, root-mean square radius, binding energy, location of low laying energy levels, magnetic momentum and also total cross section and 7 Li(n, γ) 8 Li reaction rate at a wide energy region. Within Glauber-Sitenko multiply scattering theory, the differential cross section of elastic p 8 Li-scattering has been calculated. The first and the second multiplicities of scattering on nucleons and clusters of the nucleus were taken into account in Ω multiply scattering operator. There were considered several cases when as the initial parameters both amplitudes of nucleon-nucleon and nucleon-cluster scattering were taken. Sensitivity of the differential cross section both to the different wave functions of the target-nucleus and to the parameters of the elementary amplitudes and sensitivity to the scattering multiplicities at several beam energies has been investigated. Comparison with differential cross sections of elastic p 6 Li- and p 7 Li scattering has been carried out

Galileo-invariant theory of low energy pion-nucleus scattering

International Nuclear Information System (INIS)

Mach, R.

1980-01-01

Two classes of Galileo-invariant optical models are constructed for pion elastic scattering by nuclei. The first, the two-body model, has been obtained assuming that the pion-bound nucleon dynamics is determined by the pion-nucleon kinetic energy. In deriving the second model, the (A+1)-body dynamics has been taken into account. The technique of effective nucleon momenta maintains the nonlocal propagation of the pion-target nucleon subsystem through the nucleus in contrast with the standard static approximation

Do phase-shift analyses and nucleon-nucleon potential models yield the wrong 3Pj phase shifts at low energies?

International Nuclear Information System (INIS)

Tornow, W.; Witala, H.; Kievsky, A.

1998-01-01

The 4 P J waves in nucleon-deuteron scattering were analyzed using proton-deuteron and neutron-deuteron data at E N =3 MeV. New sets of nucleon-nucleon 3 P j phase shifts were obtained that may lead to a better understanding of the long-standing A y (θ) puzzle in nucleon-deuteron elastic scattering. However, these sets of 3 P j phase shifts are quite different from the ones determined from both global phase-shift analyses of nucleon-nucleon data and nucleon-nucleon potential models. copyright 1998 The American Physical Society

ψ' and J/ψ suppression in high-energy nucleon-nucleus and nucleus-nucleus collisions

International Nuclear Information System (INIS)

Wong, Cheuk-Yin.

1995-01-01

The observed features of ψ' to J/ψ suppression in pA and nucleus-nucleus collisions can be explained in terms of a two-component absorption model. For the hard component of the absorption due to the interaction of the produced c bar c systems with baryons at high relative energies, the absorption cross sections are insensitive to the radii of the c bar c systems, as described by the Additive Quark Model. For the soft component due to the low energy c bar c interactions with soft particles produced by other baryon-baryon collisions, the absorption cross sections are greater for ψ' than for J/ψ, because the breakup threshold for ψ' is much smaller than for ψ

The nucleon-nucleon spin-orbit interaction in the Skyrme model

International Nuclear Information System (INIS)

Riska, D.O.; Dannbom, K.

1987-01-01

The spin-orbit and quadratic spin-orbit components of the nucleon-nucleon interaction are derived in the Skyrme model at the classical level. These interaction components arise from the orbital and rotational motion of the soliton fields that form the nucleons. The isospin dependent part of the spin-orbit interaction is similar to the corresponding component obtained from boson exchange mechanisms at long distances although at short distances it is weaker. The isospin independent spin-orbit component is however different from the prediction of boson exchange mechanisms and has the opposite sign. The quadratic spin-orbit interaction is weak and has only an isospin dependent component

Experimental studies and microscopic analysis of the elastic scattering of low energy nucleons

International Nuclear Information System (INIS)

Tarrats-Saugnac, Annie.

1982-05-01

Data on the elastic scattering of low energy nucleons (between 20 and 40 MeV) by nuclei distributed throughout the entire mass table are examined in the framework of a microscopic approach. Two major problems occur at these low energies which do not occur at higher energies: the Pauli principle limits the interaction possibilities of projectiles with bound nucleons in the nucleus; it is not possible to neglect the antisymmetrization between projectiles and nucleon targets resulting in the addition of a nonlocal term to the potential. A quadratic moment approximation is used. As regards the inhibition of reactions inside the nucleus by the Pauli principle, an effective interaction with a relatively simple analytical form and easy to use for systematic analyses was determined [fr

Towards the results of global analysis of data on nucleon electromagnetic structure

International Nuclear Information System (INIS)

Bilen'kaya, S.I.; Dubnicka, S.; Dubnickova, A.Z.; Strizenec, P.

1991-01-01

Peculiar features of the recent global analysis of data on the nucleon electromagnetic structure are discussed on the detail in order to reconsider reliability of the predicted result that the electron-positron annihilation into a neutron-antineutron cross-section is considerably larger that the cross-section of the electron-positron annihilation into a proton-antiproton pair. 14 refs.; 3 figs.; 3 tabs

Galileo-invariant theory of low energy pion-nucleus scattering. II

International Nuclear Information System (INIS)

Mach, R.

1983-01-01

Two classes of Galileo-invariant optical models are constructed for pion elastic scattering by nuclei. The former, the two-body model, was obtained assuming that the pion-bound nucleon dynamics is determined by the pion-nucleon kinetic energy. In deriving the latter model, the (A+1)-body dynamics was taken into account. The technique of effective nucleon momenta maintains the nonlocal propagation of the pion-target nucleon subsystem through the nucleus in contrast with the standard static approximation. (author)

Classifiers for centrality determination in proton-nucleus and nucleus-nucleus collisions

Directory of Open Access Journals (Sweden)

Altsybeev Igor

2017-01-01

Full Text Available Centrality, as a geometrical property of the collision, is crucial for the physical interpretation of nucleus-nucleus and proton-nucleus experimental data. However, it cannot be directly accessed in event-by-event data analysis. Common methods for centrality estimation in A-A and p-A collisions usually rely on a single detector (either on the signal in zero-degree calorimeters or on the multiplicity in some semi-central rapidity range. In the present work, we made an attempt to develop an approach for centrality determination that is based on machine-learning techniques and utilizes information from several detector subsystems simultaneously. Different event classifiers are suggested and evaluated for their selectivity power in terms of the number of nucleons-participants and the impact parameter of the collision. Finer centrality resolution may allow to reduce impact from so-called volume fluctuations on physical observables being studied in heavy-ion experiments like ALICE at the LHC and fixed target experiment NA61/SHINE on SPS.

Double Polarized Neutron-Proton Scattering and Meson-Exchange Nucleon-Nucleon Potential Models

International Nuclear Information System (INIS)

Raichle, B.W.; Gould, C.R.; Haase, D.G.; Seely, M.L.; Walston, J.R.; Tornow, W.; Wilburn, W.S.; Raichle, B.W.; Gould, C.R.; Haase, D.G.; Seely, M.L.; Walston, J.R.; Tornow, W.; Wilburn, W.S.; Penttilae, S.I.; Hoffmann, G.W.

1999-01-01

We report on polarized beam - polarized target measurements of the spin-dependent neutron-proton total cross-section differences in longitudinal and transverse geometries (Δσ L and Δσ T , respectively) between E n =5 and 20MeV. Single-parameter phase-shift analyses were performed to extract the phase-shift mixing parameter var-epsilon 1 , which characterizes the strength of the nucleon-nucleon tensor interaction at low energies. Consistent with the trend of previous determinations at E n =25 and 50MeV, our values for var-epsilon 1 imply a stronger tensor force than predicted by meson-exchange nucleon-nucleon potential models and nucleon-nucleon phase-shift analyses. copyright 1999 The American Physical Society

The nuclear response and the imaginary potential for nucleus-nucleus collisions

International Nuclear Information System (INIS)

Phatak, S.C.; Sinha, B.

1983-01-01

The Fermi-gas model is used in this paper to study the nucleus-nucleus collision. The field produced by one of the nuclei is considered to act on nucleons in the other nucleus, which is treated as a Fermi gas of radius R. The imaginary part of the (non-local) nucleus-nucleus potential is then computed by evaluating the energy-conserving second-order term in which the intermediate states are particle-hole excitations produced in the Fermi gas. The equivalent local potential, obtained by using the Perey-Saxon method, is compared with phenomenological imaginary potentials. Later it is shown that, in the limit of small range of non-locality, the imaginary potential can be related to the nuclear response function. With this, one can write the nuclear friction coefficient that is used in phenomenological analyses of heavy-ion collisions in terms of the imaginary potential. (orig.)

Physical meaning of the yields from hadron-nucleon, hadron-nucleus, and nucleus-nucleus collisions observed in experiments

International Nuclear Information System (INIS)

Strugalski, Z.

1995-01-01

A physical meaning of the outcomes from hadronic and nuclear collision processes at high energies is presented, as prompted experimentally. The fast and slow stages in hadron-nucleus collisions are distinguished. Hadrons are produced via intermediate objects observed in hadron-nucleus collisions. The intermediate objects may be treated as the groups of quarks or the quark bags. 37 refs

The nucleus

International Nuclear Information System (INIS)

Marano, S.

1998-01-01

In 1911 E.Rutherford discovered the nucleus. Since then the nucleus has been investigated with more and more powerful tools but it remains the main field of study of nuclear physics. As it is impossible to take into account the interaction of all the nucleons, a theory based on the hypothesis that each nucleon undergoes an average interaction force has been set up. 2 representations have emerged: the Skyrme force and the Gogny force. Both representations match experimental results but are unable to describe fission yields or the multi-fragmentation of very hot nuclei. The mean-field theory can predict the shape of the nuclei according to its energy level. An experimental program involving the Vivitron accelerator and the Euroball detector is due to begin to validate it. By bombarding targets with exotic nuclei nuclear physicists detect new structures and test their collision models. About ten years ago nuclear halos were observed with lithium 11 nuclei. In this nucleus 2 neutrons move in a space larger than the nucleus itself. This discovery has triggered the elaboration of new theories based on nuclear clusters. At very high temperatures the mean-field theory predicts that nuclear matter acts as a fluid. Following the nuclei temperature different ways of decay appear: first evaporation then multi-fragmentation and vaporization. This ultimate stage occurs around 100 milliard celsius degree temperature when the nuclei decays in a multitude of light particles. Isomeric states are studied and could be seen as a way of storing energy. In a very pedagogical way this article gives information to understand the challenges that face nuclear physics today and highlights the contributions of Cea in this field. (A.C.)

Inclusive spectra of hadrons in proton-nucleus collisions

International Nuclear Information System (INIS)

Gevorkyan, S.R.; Gulkanyan, G.R.; Kotzinyan, A.M.; Zhamkochyan, V.M.

1985-01-01

A model is proposed, which allows one to describe all exprimental data on inclusive spectra of different hadrons produced on nuclei. The model is based on the following assumptions. After the first inelastic collision with nucleon in the nucleus the proton transforms into some excited system H, which collides with the other nucleons during its passage through the nucleus. Since in inelastic collisions the slow sea partons play the dominant role, the valence quarks of this system H coincide with those of proton. Fragmentation of H into hadrons (as well as into proton) is dilated in the lab system by the Lorentz factor E/m >> 1 and so it takes place out of the nucleus. Using the methods of multiple scattering theory one can receive the connection between inclusive spectra on nuclei and those on nucleons. The calculations of inclusive spectra of different hadrons (p, p, πsup(-+), ksup(+-)) were done, and a satisfactory description of the experimental data was obtained. It should be noted that this description was done without introduction of any free parameters. Analogous models are discussed, and their diffference from the method proposed is outlined

The nucleon-nucleon correlations and the integral characteristics of the potential distributions in nuclei

International Nuclear Information System (INIS)

Knyaz'kov, O.M.; Kukhtina, I.N.

1989-01-01

The integral characteristics of the potential distribution in nuclei, namely the volume integrals, moments and mean square radii are studied in the framework of the semimicroscopic approach to the interaction of low energy nucleons with nuclei on the base of the exchange nucleon-nucleon correlations and the density dependence of effective forces. The ratio of the normalized multipole moments of potential and matter distributions is investigated. The energy dependence of the integral characteristics is analyzed. 15 refs.; 2 tabs

Nuclear energy release in hadron-nucleus collisions

International Nuclear Information System (INIS)

Strugalski, Z.; Strugalska-Gola, E.

1998-01-01

Energy release process in nuclear reactions induced by fast hadrons in hadron-nucleus collisions is discussed. Some portion of the internal nuclear energy is released when the locally damaged in a collision, and instable therefore, residual target nucleus transits itself into light nuclear fragments (nucleons, D, T) and a stable lighter final nucleus or some number of stable lighter nuclei. It is not excluded that in some of the collisions the induced intranuclear nuclear reactions may be energy overcompensating. Corresponding reconnaissance should be made - in analysing the nuclear reactions induced in hadron-nucleus collisions

Unmatter Entities inside Nuclei, Predicted by the Brightsen Nucleon Cluster Model

Directory of Open Access Journals (Sweden)

Smarandache F.

2006-01-01

Full Text Available Applying the R. A. Brightsen Nucleon Cluster Model of the atomic nucleus we discuss how unmatter entities (the conjugations of matter and antimatter may be formed as clusters inside a nucleus. The model supports a hypothesis that antimatter nucleon clusters are present as a parton (sensu Feynman superposition within the spatial confinement of the proton (1H1, the neutron, and the deuteron (1H2. If model predictions can be confirmed both mathematically and experimentally, a new physics is suggested. A proposed experiment is connected to othopositronium annihilation anomalies, which, being related to one of known unmatter entity, orthopositronium (built on electron and positron, opens a way to expand the Standard Model.

Atomic Nuclei Utter Disintegration into Nucleons by High Energy Nuclear Projectiles

International Nuclear Information System (INIS)

Strugalski, Z.

1994-01-01

The disintegration process of atomic nuclei by high energy nuclear projectiles is described. The physical basis for this process is the passage of hadrons through layers of intranuclear matter accompanied by the nucleon emission from the target nuclei observed in experiments; kinetic energies of the nucleons are from about 20 up to about 400 MeV - in the target nucleus reference system. 22 refs., 3 tabs

The isospin dependence of the nucleus-nucleus inelastic cross-section at high energy

International Nuclear Information System (INIS)

Rashdan, M.; Farhan, A.M.; Hassib, E.; Kareem, W. Abdel

2006-01-01

The isospin dependence of the nucleus-nucleus inelastic cross-section at high energy is investigated within the multiple scattering theory. The multiple integrals are evaluated by Monte Carlo method as well as by the optical limit approximation of the Glauber model. Calculations are performed for 14-23 N, 16-24 O and 18-26 F isotopes colliding with carbon target around 1 GeV. It is found that rms radii and the density distributions show a halo structure of 22 N, 23 O and 24 F

A semiclassical distorted wave theory of inclusive nucleon inelastic scattering to continuum

International Nuclear Information System (INIS)

Kawai, M.; Luo, Y.L.

1989-01-01

A semiclassical model is presented for the one step process of the inclusive nucleon inelastic scattering to the continuum. In the model, we use distorted waves for describing the motion of the incident and the exit nucleon, and the Thomas-Fermi model for the initial and the final states of the target nucleus. The averaged two-body cross section inside the nucleus is given by Kikuchi-Kawai expression. The model gives a closed form formula for the double differential cross section. No free parameter is included. We apply the model to the inclusive nucleon inelastic scattering from Al, Sn and Bi at 62 MeV, and Ni at 164 MeV. The angular distribution experimental data are reproduced very well except for small and large angle regions. The calculated energy spectra agree with the experimental data very well in the middle angle region and at high exit energies. (author)

Nuclear sizes and intranuclear matter distribution -- from hadron-nucleus collisions

International Nuclear Information System (INIS)

Strugalska-Gola, E.; Strugalski, Z.

1999-01-01

The method of intranuclear matter studies by hadronic projectiles is found and worked out. It is tested on the pion-xenon nucleus collision events. Target-nucleus size and nucleon density distributions in it were estimated and described by formulas prompted experimentally

Phenomenological model for non-equilibrium deuteron emission in nucleon induced reactions

International Nuclear Information System (INIS)

Broeders, C.H.M.; Konobeyev, A.Yu.

2005-01-01

A new approach is proposed for the calculation of non-equilibrium deuteron energy distributions in nuclear reactions induced by nucleons of intermediate energies. It combines the model of the nucleon pick-up, the coalescence and the deuteron knock-out. Emission and absorption rates for excited particles are described by the pre-equilibrium hybrid model. The model of Sato, Iwamoto, Harada is used to describe the nucleon pick-up and the coalescence of nucleons from the exciton configurations starting from (2p, 1h). The model of deuteron knock-out is formulated taking into account the Pauli principle for the nucleon-deuteron interaction inside a nucleus. The contribution of the direct nucleon pick-up is described phenomenologically. The multiple pre-equilibrium emission of particles is taken into account. The calculated deuteron energy distributions are compared with experimental data from 12 C to 209 Bi. (orig.)

Separation of the transverse and longitudinal structure functions for the (e,e'p) coincidence reaction on the 40Ca nucleus

International Nuclear Information System (INIS)

Reffay-Pikeroen, Dominique

1987-01-01

The bound-nucleon current has been investigated in the region of the quasi-elastic peak, with (e,e'p) coincidence measurements where by the one-nucleon knock-out process is selected. This study is refined by the measurement of the separate transverse and longitudinal structure functions. The (e,e'p) reaction has been performed on the 40 Ca nucleus in a momentum transfer range from 330 to 825 MeV/c. We have chosen a range of proton momenta in the nucleus from 40 to 140 MeV and a missing energy range from 8 to 60 MeV which corresponds to the shells 1d3/2, 1d5/2, 2s1/2, 1s1/2, 1p3/2, 1p1/2 of 39 K as predicted by the shell model. The first aim of these measurements was to verify, on an exclusive process, the results of the inclusive measurements on this nucleus with transverse/longitudinal separation, since the inclusive results are presently difficult to interpret. More generally, the aim of this kind of measurements is to test the validity of the traditional theoretical approach to the quasi-elastic scattering: Schroedinger equation, impulse approximation, choice of a prescription for the off shell effect on the nucleonic current keeping the free nucleon electromagnetic form factors. The answer to the first question is the observation of a quenching of the longitudinal/transverse ratio, consistent with the effect observed in the inclusive experiments. Regarding the most general aspect of the study of the electromagnetic structure of the bound nucleus, this experiment has brought some entirely new results about the momentum transfer dependence of its electric and magnetic form factors. These results do not suggest any important deformation of the nucleon in the nucleus. We were able to derive an upper limit of 4 pc for a possible increase of the magnetic radius of the bound proton. Regarding the electric radius, the data still remain too inaccurate to draw final conclusions. (author) [fr

The picture of the nuclei disintegration mechanism - from nucleus-nucleus collision experimental data at high energies

International Nuclear Information System (INIS)

Strugalska-Gola, E.; Strugalski, Z.

1997-01-01

Experimental data on nuclear collisions at high energies, mainly obtained from photographic emulsions, are considered from the point of view of the picture of the nuclear collision processes mechanisms prompted experimentally. In fact, the disintegration products of each nucleus involved in a nuclear collision, in its own rest-frame, are similar to that produced by the impact of a number of nucleons of velocity equal to that of the moving primary nucleus

Neutrino-nucleus cross section in the impulse approximation regime

International Nuclear Information System (INIS)

Benhar, Omar; Farina, Nicola

2005-01-01

In the impulse approximation regime the nuclear response to a weakly interacting probe can be written in terms of the measured nucleon structure functions and the target spectral function, yielding the energy and momentum distribution of the constituent nucleons. We discuss a calculation of charged current neutrino-oxygen interactions in the quasielastic channel, carried out within nuclear many body theory. The proposed approach, extensively and successfully employed in the analysis of electron-nucleus scattering data, allows for a parameter free prediction of the neutrino-nucleus cross section, whose quantitative understanding will be critical to the analysis of the next generation of high precision neutrino oscillation experiments

Compound-nuclear tests of time reversal invariance in the nucleon-nucleon interaction

International Nuclear Information System (INIS)

French, J.B.; Pandey, A.; Smith, J.

1987-01-01

The theory for the effects of time-reversal noninvariance (TRNI) in complex systems is reviewed. Applied to the compound-nuclear data for energy-level, width and cross-section fluctuations (the latter for detailed-balance pairs of reactions proceeding through the compound nucleus) this gives bounds on multiparticle TRNI Hamiltonian matrix elements. Using a fluctuation-free form of statistical spectroscopy the results are reduced to bounds on α, the relative magnitude of the TRNI nucleon-nucleon interaction. The level and width analyses for heavy nuclei gave α ≤ 2 x 10 -3 at high (∼99%) statistical confidence; preliminary calculations for detailed balance with 24 Mg(α,p) 27 Al and its inverse gives α ≤ 4 x 10 -3 at the same high confidence, but ≤0.2 x 10 -3 at 80% confidence. Suggestions are made about experiments which should yield sharper bounds. 28 refs., 1 tab

Present status of nucleon-meson transport code NMTC/JAERI

International Nuclear Information System (INIS)

Takada, H.; Meigo, S.

2001-01-01

The nucleon-meson transport code NMTC/JAM has been developed for the neutronics design study of the joint project for high-intensity proton accelerators with a power of mega-watts. The applicable energy range is extended by the inclusion of the jet AA microscopic transport model (JAM). The nucleon-nucleus cross sections are also updated for accurate transport calculation. The applicability of NMTC/JAM is studied through the analyses of thick target experiments such as neutron transmission through shield and activation reaction rate measurements. (orig.)

Target dependence of K+-nucleus total cross sections

International Nuclear Information System (INIS)

Jiang, M.F.; Ernst, D.J.; Chen, C.M.

1995-01-01

We investigate the total cross section and its target dependence for K + -nucleus scattering using a relativistic momentum-space optical potential model which incorporates relativistically normalized wave functions, invariant two-body amplitudes, covariant kinematics, and an exact full-Fermi averaging integral. The definition of the total cross section in the presence of a Coulomb interaction is reviewed and the total cross section is calculated in a way that is consistent with what is extracted from experiment. In addition, the total cross sections for a nucleus and for the deuteron are calculated utilizing the same theory. This minimizes the dependence of the ratio of these cross sections on the details of the theory. The model dependence of the first-order optical potential calculations is investigated. The theoretical results are found to be systematically below all existing data

Momentum dependence of the imaginary part of the ω- and η{sup '}-nucleus optical potential

Energy Technology Data Exchange (ETDEWEB)

Friedrich, Stefan; Nanova, Mariana [II. Physikalisches Institut, Justus-Liebig-Universitaet Giessen (Germany); Collaboration: CBELSA/TAPS-Collaboration

2016-07-01

The attenuation of ω- and η{sup '}-mesons in cold nuclear matter has been studied in photonuclear reactions on {sup 12}C and {sup 93}Nb for photon energies of 1.2-2.9 GeV, using the tagged photon beam at the ELSA accelerator. ω- and η{sup '}-mesons have been identified via the ω → π{sup 0}γ and η{sup '} → π{sup 0}π{sup 0}η decays, respectively, registered with the CBELSA/TAPS detector system. The momentum dependence of the transparency ratio has been determined for both mesons. Results on the in-medium width of the ω- and η{sup '}-meson and the corresponding meson-nucleon inelastic cross sections will be compared to previous experimental data and recent theoretical predictions. The energy dependence of the imaginary part of the ω- and η{sup '}-nucleus optical potential has been extracted. The higher statistics and finer binning of the present data allow an extrapolation to the production threshold. Corresponding values for the imaginary part of the optical potential will be discussed in view of recent determinations of the ω and η{sup '} scattering lengths.

Study of single-nucleon spectroscopic characteristics in light nuclei

International Nuclear Information System (INIS)

Zhusupova, K.A.

1998-01-01

Single-nucleon characteristics of 1 p-shell nuclei are investigated in the thesis. These characteristics are necessary for describing nuclear processes leaded to separation of target nuclei or to addition of one nucleon to it. Multi-particle shell model and three-body cluster model (for 6 L i and 9 Be) are used. It is shown that shell model explains well spectroscopic S-factors for stripping and pick-up reactions of nucleon. Three body α2 N-model reproduces well S-factors and momentum distribution extracted from (e, e p) reactions for separation of proton from ground state of 6 L i nucleus accompanied by appearance of ground and high exited states of 5 He nucleolus. The classification and explanation for small value nucleon partial widths for high lying states for odd nuclei 1 p-shell with isospin T=3/2 are given. (author)

The spin-dependent neutralino-nucleus form factor for 127I

International Nuclear Information System (INIS)

Ressell, M.T.

1996-01-01

We present the results of detailed shell model calculations of the spin-dependent elastic form factor for the nucleus 127 I. the calculations were performed in extremely large model spaces which adequately describe the configuration mixing in this nucleus. Good agreement between the calculated and experimental values of the magnetic moment are found. Other nuclear observables are also compared to experiment. The dependence of the form factor upon the model space and effective interaction is discussed

Electromagnetic processes in nucleus-nucleus collisions relating to space radiation research

Science.gov (United States)

Norbury, John W.

1992-01-01

Most of the papers within this report deal with electromagnetic processes in nucleus-nucleus collisions which are of concern in the space radiation program. In particular, the removal of one and two nucleons via both electromagnetic and strong interaction processes has been extensively investigated. The theory of relativistic Coulomb fission has also been developed. Several papers on quark models also appear. Finally, note that the theoretical methods developed in this work have been directly applied to the task of radiation protection of astronauts. This has been done by parameterizing the theoretical formalism in such a fashion that it can be used in cosmic ray transport codes.

Invariant potential for elastic pion--nucleus scattering. Technical report No. 75-075

International Nuclear Information System (INIS)

Cammarata, J.B.; Banerjee, M.K.

1975-04-01

From the Wick-Dyson expansion of the exact propagator of a pion in the presence of a nucleus an invariant potential for crossing symmetric, elastic pion-nucleus scattering is obtained in terms of a series of pion-nucleon diagrams. The Chew-Low theory is used to develop a model in which the most important class of diagrams is effectively summed. Included in this model is the Exclusion Principle restriction on the pion-bound nucleon interaction, the effects of the binding of nucleons, a kinematic transformation of energy from the lab to the πN center of mass frames, and the Fermi motion and recoil of the target nucleons. From a numerical study of the effects of these processes on the π- 12 C total cross section, the relative importance of each is determined. Other processes contributing to the elastic scattering of pions not included in the present model are also discussed. (9 figures) (U.S.)

High energy nuclear collisions in the few GeV/nucleon region: projectile and target fragmentation

International Nuclear Information System (INIS)

Schroeder, L.S.

1980-06-01

A general review of nucleon-nucleus and nucleus-nucleus collisions for incident energies <10 GeV/nucleon is presented. The division of these interactions into peripheral and central collisions is briefly discussed. Subjects treated include the following: target and projectile fragmentation systematics, production of exotic nuclear fragments, studies of multiparticle final states, total cross section measurements, results from an experiment that indicate the production of projectile fragments with an anomalously short reaction mean free path, high-energy particle production at backward angles beyond simple N-N kinematic limits, and recent results on backward particle emission in studies with the Berkeley streamer chamber. Both the particle and nuclear physics aspects that are present are considered. A brief discussion of future trends in this energy range ends the presentation. 65 references, 37 figures

Impact Parameter Dependence of the Double Neutron/Proton Ratio of Nucleon Emissions in Isotopic Reaction Systems

International Nuclear Information System (INIS)

Xun-Chao, Zhang; Gao-Chan, Yong; Bao-An, Li; Lie-Wen, Chen

2009-01-01

Within the transport model IBUU04, we investigate the double neutron/proton ratio of free nucleons taken from two reaction systems using two Sn isotopes at a beam energy of 50 MeV/nucleon and with impact parameters 2 fm, 4 fm and 8 fm, respectively. It is found that the double neutron/proton ratio from peripheral collisions is more sensitive to the density dependence of the symmetry energy than those from mid-central and central collisions. (nuclear physics)

Nucleon-nucleon theory and phenomenology

International Nuclear Information System (INIS)

Signell, P.

1981-03-01

This project involves five inter-related subprojects: (1) derivation of the intermediate range nucleon-nucleon interaction using a new method that utilizes much shorter and simpler analytic continuation through the unphysical region that lies between the πN and ππ physical regions of the N anti N → ππ amplitude (with significantly improved accuracy for the nucleon-nucleon interaction); (2) construction of a short range phenomenological potential that, with the theoretical part mentioned above, gives a precise fit to the nucleon-nucleon data and is parameterized for easy use in nucleon calculations; (3) phase shift analyses of the world data below 400 MeV, especially the large amount of very precise data below 20 MeV and the new data near 55 MeV that have never been analyzed properly; (4) the introduction of a K-matrix formulation of the Optimal Polynomial Expansion in order to accelerate convergence of the partial wave series at LAMPF energies; and (5) setting up of a cooperatively evaluated permanent nucleon-nucleon data bank in the 0-1200 MeV range that can be used by all nucleon-nucleon reseachers

Isospin dependence of physical observables in Incomplete Fusion reactions at 25 MeV/nucleon

Energy Technology Data Exchange (ETDEWEB)

Lombardo, I., E-mail: ilombardo@lns.infn.i [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN Laboratori Nazionali del Sud, Catania (Italy); Agodi, C.; Alba, R. [INFN Laboratori Nazionali del Sud, Catania (Italy); Amorini, F. [INFN, Sezione di Catania, Catania (Italy); Dipartimento di Fisica, Universita di Catania, Catania (Italy); Anzalone, A. [INFN Laboratori Nazionali del Sud, Catania (Italy); Berceanu, I. [Institute for Physics and Nuclear Engineering, Bucharest (Romania); Cardella, G. [INFN, Sezione di Catania, Catania (Italy); Cavallaro, S. [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN Laboratori Nazionali del Sud, Catania (Italy); Chatterjee, M.B. [Saha Institute of Nuclear Physics, Kolkata (India); Coniglione, R. [INFN Laboratori Nazionali del Sud, Catania (Italy); DeFilippo, E. [INFN, Sezione di Catania, Catania (Italy); DiPietro, A.; Figuera, P. [INFN Laboratori Nazionali del Sud, Catania (Italy); Geraci, E.; Giuliani, G.; Grassi, L. [Dipartimento di Fisica, Universita di Catania, Catania (Italy); INFN, Sezione di Catania, Catania (Italy); Grzeszczuk, A. [Institute of Physics, University of Silesia, Katowice (Poland); LaGuidara, E. [INFN, Sezione di Catania, Catania (Italy); Centro Siciliano di Fisica Nucleare e Struttura della Materia, Catania (Italy); Lanzalone, G. [INFN Laboratori Nazionali del Sud, Catania (Italy); Libera Universita Kore, Enna (Italy); LeNeindre, N. [LPC Caen, CNRS-IN2P3, ENSICAEN, Universite de Caen, Caen (France)

2010-03-01

Isospin dependence of dynamical and thermodynamical physical quantities observed in the reactions {sup 40}Ca + {sup 40,48}Ca and {sup 40}Ca + {sup 46}Ti at 25 MeV/nucleon has been analyzed by means of the CHIMERA multi-detector.

One-boson-exchange approach to dilepton production in nucleon-nucleon collisions

International Nuclear Information System (INIS)

Haglin, K.L.

1991-01-01

The author calculates energy-dependent nucleon-nucleon elastic cross sections and electron-positron pair production differential cross sections for the processes pp → pp, np → np, and pp → ppe + e - , np → npe + e - at laboratory kinetic energies in the 1-5 GeV range. These calculations will be based on a one-boson-exchange (π, ρ, ω, σ, δ, η) approximation to the nucleon-nucleon scattering problem. Strong form factors are included in a manner which preserves gauge invariance. He finds excellent results as compared with data for the total elastic cross sections. The calculate differential elastic cross sections show only qualitative agreement with data. For dilepton production in n-p scattering the model overestimates the number of pairs as compared with proton on beryllium data. For the p-p case he finds the tensor coupling of the ρ to the nucleons to be clearly dominant. Data do not yet exist for the p-p case at these energies: the author predicts them

Nuclear re-interaction effects in quasi-elastic neutrino nucleus scattering

Energy Technology Data Exchange (ETDEWEB)

Co, G.; Bleve, C.; De Mitri, I.; Martello, D

2002-11-01

The quasi-elastic {nu}-nucleus cross section has been calculated by using a Fermi gas model corrected to consider the re-scattering between the emitted nucleon and the rest nucleus. As an example of the relevance of this effect we show results for the muon production cross section on {sup 16}O target.

Limits on the Spin-Dependent WIMP-Nucleon Cross Sections from the First Science Run of the ZEPLIN-III Experiment

International Nuclear Information System (INIS)

Lebedenko, V. N.; Bewick, A.; Currie, A.; Davidge, D.; Dawson, J.; Horn, M.; Howard, A. S.; Jones, W. G.; Joshi, M.; Liubarsky, I.; Lyons, K.; Quenby, J. J.; Sumner, T. J.; Thorne, C.; Walker, R. J.; Araujo, H. M.; Edwards, B.; Barnes, E. J.; Ghag, C.; Murphy, A. StJ.

2009-01-01

We present new experimental constraints on the WIMP-nucleon spin-dependent elastic cross sections using data from the first science run of ZEPLIN-III, a two-phase xenon experiment searching for galactic dark matter weakly interacting massive particles based at the Boulby mine. Analysis of ∼450 kg·days fiducial exposure allow us to place a 90%-confidence upper limit on the pure WIMP-neutron cross section of σ n =1.9x10 -2 pb at 55 GeV/c 2 WIMP mass. Recent calculations of the nuclear spin structure based on the Bonn charge-dependent nucleon-nucleon potential were used for the odd-neutron isotopes 129 Xe and 131 Xe. These indicate that the sensitivity of xenon targets to the spin-dependent WIMP-proton interaction could be much lower than implied by previous calculations, whereas the WIMP-neutron sensitivity is impaired only by a factor of ∼2.

Approximate treatment of the deuteron+nucleus interaction in the resonating-group formulation

International Nuclear Information System (INIS)

Kaneko, T.

1995-01-01

A simplified version of the microscopic resonating-group method (RGM), called model K, is formulated for the deuteron+nucleus problem by making the simplifications of approximately treating the total center-of-mass motion and keeping only the direct and knockon-exchange terms. For these terms, the important point is that they can be analytically derived without much difficulty, with the consequence that the adoption of this model can enhance the general utility of the RGM by rendering the calculations feasible even in heavy nuclear systems. By utilizing the information obtained from previous investigations in the nucleon+nucleus case and by studying the analytical structure of the RGM kernel functions, it can be determined that this model for deuteron+nucleus scattering should work well when the nucleon-number ratio of the target and incident nuclei is larger than about 10 and when the scattering energy is higher than about 20 MeV/nucleon. A test comparison with exact RGM results for d+ 16 O scattering at 30 MeV and a fit to experiment for d+ 40 Ca scattering at 49.52 MeV yield rather convincing evidence that this model has great simplicity and generality, and can be employed to conduct a systematic and large-scale study of existing data on deuteron+nucleus scattering. (orig.)

Effects of in-medium nucleon-nucleon cross sections on stopping observable and ratio of free protons in heavy-ion collisions at 400 MeV/nucleon

Energy Technology Data Exchange (ETDEWEB)

Su, Jun; Huang, Ching-Yuan [Sun Yat-sen University, Sino-French Institute of Nuclear Engineering and Technology, Zhuhai (China); Xie, Wen-Jie [Yuncheng University, Department of Physics, Yuncheng (China); Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Zhang, Feng-Shou [Beijing Normal University, The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing (China); Beijing Radiation Center, Beijing (China); National Laboratory of Heavy Ion Accelerator of Lanzhou, Center of Theoretical Nuclear Physics, Lanzhou (China)

2016-07-15

The effects of in-medium nucleon-nucleon cross sections on the stopping observable and ratio of free protons in heavy-ion collisions at 400 MeV/nucleon have been investigated within the framework of the IQMD+GEMINI model. Five kinds of in-medium corrections of nucleon-nucleon cross sections, which are considerably different in the referred energy and density, have been used in the model. It has been found that calculations of the stopping decrease when the in-medium cross sections decrease. Moreover, the ratio of free protons R{sub p} depends not only on the value of the in-medium factors but also on its isospin dependence. In order to investigate the isospin effect of in-medium factors on the ratio of free protons R{sub p}, the isospin dependence of in-medium factors has been adjusted and used in the model. The calculations have shown that the isospin dependence of in-medium factors does not impact the stopping, but impacts the ratio of free protons R{sub p}. When the in-medium factors relation f{sub nn}{sup med} > f{sub pp}{sup med} is used in the model, the calculated values of R{sub p} are larger than those in the f{sub nn}{sup med} < f{sub pp}{sup med} case. (orig.)

Impact parameter and energy dependence of the dynamics of nucleus-nucleus collisions below 100 MeV/u

International Nuclear Information System (INIS)

Peter, J.

1990-10-01

The multidetector array Mur + Tonneau has been used to perform a 4π detection of charged particles and fragments emitted in reactions between 40 Ar, at energies ranging from 25 to 85 MeV/u, and 27 Al or 58 Ni target. The events have been sorted as a function of the impact parameter value, using a new global variable, the average parallel velocity. The pre-equilibrium emission from the interaction region increases strongly when the incident energy increases and when the impact parameter decreases. It severely limits the mass and excitation energy of the equilibrated partial fusion nuclei, even in central collisions. The collective transverse momentum in the reaction plane (flow) is observed to strongly vary as a function of impact parameter and incident energy. Its value falls to zero in the range 70-80 MeV/u for central collisions. These results are compared to predictions based on the Landau-Vlasov and Boltzmann equations in order, to get information on the nucleon-nucleon cross section in medium and the equation of state of nuclear matter. 8 figs

Low mass dimuon production in 200 GeV/c per nucleon sulphur ion collisions on heavy targets

International Nuclear Information System (INIS)

Vasseur, G.

1989-11-01

The HELIOS/2 experiment at CERN studies, among other features, low mass muon pairs production in 200 GeV/c per nucleon sulphur-nucleus interactions, compared to proton-nucleus interactions at the same energy. As muons interact weakly with nuclear matter, they provide relatively clean information on the initial state of these collisions. In addition, an anomalous production of low mass dileptons, with an unusual quadratic dependence upon multiplicity, could be a signature of quark-gluon plasma. To get the target produced dimuon signal, two sources of backgrounds have to be removed: the dimuon production in the dump and the pion and kaon decays into muons. After subtraction of these backgrounds, acceptance correction and normalization, a dimuon signal is obtained, especially at low mass. It is compatible with known sources of low mass dimuons: vector meson decays and Dalitz pairs. In proton-nucleus, this result is in contradiction with previous experiments. In sulphur-nucleus, no great effect giving evidence of quark-gluon plasma formation is observed [fr

Relations between the simultaneous and sequential transfer of two nucleons

International Nuclear Information System (INIS)

Satchler, G.R.

1982-01-01

The transfer of two nucleons between projectile and target in a direct or peripheral reaction such as (p,t) or ( 16 O, 14 C) may occur in one-step or two-steps. These we refer to as simultaneous and sequential transfers, respectively. In the former, the interaction acts once and both nucleons are transferred. In the latter, the interaction acts once to transfer one nucleon, the system then propagates in one or more intermediate states and is followed by a second action of the interaction to transfer the second nucleon. This process may be symbolized for the above examples as (p,d;d,t) and ( 16 O, 15 N; 15 N, 14 C), implying the intermediate formation of a deuteron or the nucleus 15 N. (Of course, the intermediate system may exist in more than one state of excitation). For simplicity, the (t,p) reaction is chosen to illustrate the theory

The isospin dependent nucleon–nucleon inelastic cross section in the nuclear medium

Directory of Open Access Journals (Sweden)

Qingfeng Li

2017-10-01

Full Text Available The calculation of the energy-, density-, and isospin-dependent Δ production cross sections in nucleon–nucleon (NN scattering σNN→NΔ⁎ has been performed within the framework of the relativistic BUU approach. The NΔ cross sections are calculated in Born approximation taking into account the effective mass splitting of the nucleons and Δs in asymmetric matter. Due to the different mass splitting for neutron, proton and differently charged Δs, it is shown that, similar to the NN elastic ones, the reductions of NΔ inelastic cross sections in isospin-asymmetric nuclear medium are different from each other for all the individual channels and the effect is largest and of opposite sign for the Δ++ and Δ− states. This approach is also compared to calculations without effective mass splitting and with splitting derived from Dirac–Brueckerner (DB calculations. The isospin dependence of the NΔ cross sections is expected to influence the production of π+ and π− mesons as well as their yield ratio, and thus affect the use of the latter quantity as a probe of the stiffness of the symmetry energy at supranormal densities.

Charmonium-nucleon interactions from the time-dependent HAL QCD method

Science.gov (United States)

Sugiura, Takuya; Ikeda, Yoichi; Ishii, Noriyoshi

2018-03-01

The charmonium-nucleon effective central interactions have been computed by the time-dependent HAL QCD method. This gives an updated result of a previous study based on the time-independent method, which is now known to be problematic because of the difficulty in achieving the ground-state saturation. We discuss that the result is consistent with the heavy quark symmetry. No bound state is observed from the analysis of the scattering phase shift; however, this shall lead to a future search of the hidden-charm pentaquarks by considering channel-coupling effects.

The A-dependence of deep inelastic lepton-nuclear scattering from 6-quark clustering

International Nuclear Information System (INIS)

Chemtob, M.; Peschanszi, R.

1984-03-01

The correction to the nucleon valence quark structure functions implied by 6-quark clustering in nuclei are found to be in remarkable agreement with recent data from S.L.A.C. on the A-dependence of electron-nucleus deep inelastic scattering

Study of Relativistic Nucleus - Nucleus Collisions

CERN Multimedia

2002-01-01

The aim of the experiment is to survey the reaction mechanisms involved in the collision of 60~GeV/nucleon and 200~GeV/nucleon light ions ($^{16}$0 and $^{32}$S provided by a new GSI-LBL injector) with different nuclei, to determine the stopping power of nuclear matter and to search for evidence of the formation of quark matter by comparison to hadron-nucleus reactions at the same incident energies. \\\\ The experimental set-up consists of a 2 m Streamer Chamber in the Vertex Magnet used to detect all the charged particles emerging from the interaction as well as the neutral strange particles that decay inside the chamber. The high energy of the forward-going particles are detected by four sets of calorimeters. A highly segmented Photon Position Detector (PPD) backed up by a 240 segment Ring Calorimeter will cover one unit of rapidity around mid-rapidity. An Intermediate Calorimeter will cover the rest of the forward phase space except for the region around beam rapidity, where a Veto Calorimeter will detect be...

Proton induced nucleon knockout from 40Ca in the Dirac impulse approximation

International Nuclear Information System (INIS)

Maxwell, O.V.; Cooper, E.D.

1989-12-01

The (p,2p) reaction on 40 Ca at incident proton energies of 200 and 300 MeV is examined within a Dirac distorted wave impulse approximation. The relativistic Love-Franey t-matrix is evaluated at the nucleon-nucleon laboratory energy (as defined within the plane wave approximation), rather than the nucleon-nucleus laboratory energy. Particular attention is paid to the sensitivity of the calculated cross sections and analyzing powers to the properties of the bound states employed. It is found that the analyzing powers depend very little on the bound state properties, while the cross sections depend significantly only on the rms radii of the bound state wave functions. A major success of the model is its ability to fit the cross section data over a particular range of momentum transfers at both 200 and 300 MeV with the same bound state potential. Outside this momentum transfer range, the predicted cross sections are too low. The calculated analyzing powers agree well with the data at 200 MeV, but disagree with the data at 300 MeV. Values for the rms radii of the 1D 3/2 and 1D 5/2 states in 40 Ca are derived from the requirement that the peak positions of the calculated cross sections at 300 MeV agree with the empirical peak positions. Some preliminary results are also reported for neutron knockout from 40 Ca at 150 MeV

Models of direct reactions and quantum pre-equilibrium for nucleon scattering on spherical nuclei

International Nuclear Information System (INIS)

Dupuis, M.

2006-01-01

When a nucleon collides with a target nucleus, several reactions may occur: elastic and inelastic scatterings, charge exchange... In order to describe these reactions, different models are involved: the direct reactions, pre-equilibrium and compound nucleus models. Our goal is to study, within a quantum framework and without any adjustable parameter, the direct and pre-equilibrium reactions for nucleons scatterings off double closed-shell nuclei. We first consider direct reactions: we are studying nucleon scattering with the Melbourne G-matrix, which represents the interaction between the projectile and one target nucleon, and with random phase approximation (RPA) wave functions which describe all target states. This is a fully microscopic approach since no adjustable parameters are involved. A second part is dedicated to the study of nucleon inelastic scattering for large energy transfer which necessarily involves the pre-equilibrium mechanism. Several models have been developed in the past to deal with pre-equilibrium. They start from the Born expansion of the transition amplitude which is associated to the inelastic process and they use several approximations which have not yet been tested. We have achieved some comparisons between second order cross sections which have been calculated with and without these approximations. Our results allow us to criticize some of these approximations and give several directions to improve the quantum pre-equilibrium models. (author)

Multiparticle excitations in the 149 Gd superdeformed nucleus. Signature of new C4 nucleus symmetry

International Nuclear Information System (INIS)

Theisen, C.

1995-01-01

The use of 8 π and EUROGAM phase I multi-detectors for the study of high spin states of 149 Gd nucleus has revealed unexpected new phenomenons about the superdeformation in this nucleus. The new excited bands confirm the omnipresence of twin bands phenomenon. A new multi-particle excitation (two protons and one neutron) has been discovered. Thanks to the second generation EUROGAM detector, unexpected discoveries such as C 4 symmetry, level interactions, complete backbending were obtained for the second potential well. The knowledge of interacting levels gives informations about the nucleon-nucleon residual interaction and could allow the determination of SD bands excitation energy. The complex processing and analysis of high multiplicity events has led to the development of new computing tools. An automatic band research program has been written for the discovery of new excited bands, and an exact method for the elimination of uncorrected events has been developed. The improvements of multi-detector performances should allow the discovery of more exceptional phenomenons and new anomalies in the SD bands. (J.S.). 222 refs., 86 figs., 38 tabs

Experimental studies of pion-nucleus interactions at intermediate energies

International Nuclear Information System (INIS)

1991-01-01

This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991 under a great from the US Department of Energy. Most of these studies have involved investigations of various pion-nucleus interactions. The work has been carried out both with the LAMPF accelerator at the Los Alamos National Laboratory and with the cyclotron at the Paul Scherrer Institute (PSI) near Zurich, Switzerland. Part of the experimental work involves measurements of new data on double-charge-exchange scattering, using facilities at LAMPF which we helped modify, and on pion absorption, using a new detector system at PSI that covers nearly the full solid-angle region which we helped construct. Other work involved preparation for future experiments using polarized nuclear targets and a new high-resolution spectrometer system for detecting π 0 mesons. We also presented several proposals for works to be done in future years, involving studies related to pi-mesonic atoms, fundamental pion-nucleon interactions, studies of the difference between charged and neutral pion interactions with the nucleon, studies of the isospin structure of pion-nucleus interactions, and pion scattering from polarized 3 He targets. This work is aimed at improving our understanding of the pion-nucleon interaction, of the pion-nucleus interaction mechanism, and of nuclear structure

The quark model and the nature of the repulsive core of the nucleon-nucleon interaction

International Nuclear Information System (INIS)

Faessler, A.; Fernandez, F.; Luebeck, G.; Shimizu, K.

1982-01-01

The nature of the repulsive core of the nucleon-nucleon is studied in the quark model. The resonating group equation for nucleon-nucleon scattering is solved with the colour Fermi-Breit interaction including further a linear or quadratic confinement potential. It is shown that the colour magnetic interaction which is adjusted to the Δ-nucleon mass splitting favours the orbital symmetry and disfavours the completely symmetric orbital state. For the important orbital symmetry the relative S wave function between the two nucleons has to have a node. In the framework of the resonating group including the NN, ΔΔ and the hidden colour (CC) channels it is shown that this node produces a 3 S and 1 S phase shift which is identical to a hard core phase shift with a hard core radius γ 0 between 0.3 and 0.6 fm depending on the assumed root mean square radius of the quark part of the nucleon. (orig./HSI)

Medium energy inelastic proton-nucleus scattering with spin dependent NN interaction

International Nuclear Information System (INIS)

Ahmad, I.; Auger, J.P.

1981-12-01

The previously proposed effective profile expansion method for the Glauber multiple scattering model calculation has been extended to the case of proton-nucleus inelastic scattering with spin dependent NN interaction. Using the method which turns out to be computationally simple and of relatively wider applicability, a study of sensitivity of proton-nucleus inelastic scattering calculation to the sometimes neglected momentum transfer dependence of the NN scattering amplitude has been made. We find that the calculated polarization is particularly sensitive in this respect. (author)

Test of weak and strong factorization in nucleus-nucleuscollisions atseveral hundred MeV/nucleon

Energy Technology Data Exchange (ETDEWEB)

La Tessa, Chiara; Sihver, Lembit; Zeitlin, Cary; Miller, Jack; Guetersloh, Stephen; Heilbronn, Lawrence; Mancusi, Davide; Iwata,Yoshiuki; Murakami, Takeshi

2006-06-21

Total and partial charge-changing cross sections have been measured for argon projectiles at 400 MeV/nucleon in carbon, aluminum, copper, tin and lead targets; cross sections for hydrogen were also obtained, using a polyethylene target. The validity of weak and strong factorization properties has been investigated for partial charge-changing cross sections; preliminary cross section values obtained for carbon, neon and silicon at 290 and 400 MeV/nucleon and iron at 400 MeV/nucleon, in carbon, aluminum, copper, tin and lead targets have been also used for testing these properties. Two different analysis methods were applied and both indicated that these properties are valid, without any significant difference between weak and strong factorization. The factorization parameters have then been calculated and analyzed in order to find some systematic behavior useful for modeling purposes.

Nucleon pairs as the building blocks of a nucleus

International Nuclear Information System (INIS)

Trajdos, M.; Zajac, K.

1989-01-01

The effects induced by the interplay isovesctor and isoscalar components of the residual nucleon interactions were studied in the model based on six bosons: s μ + with J=0, T=1, μ=O,±1 and p μ + with J=1, μ=0, ±1, T=0. Low-lying energy levels, E2-transitions, p-boson structure of eigenstates, percentage of α clusters, (p,t) reactions and α elastic scattering were searched in even-even 156-166 Dy and N=92, Z=56-58 nuclei. 18 refs.; 8 figs.; 1 tab

Search for few-nucleon correlations in doubly inclusive processes

International Nuclear Information System (INIS)

Strikman, M.I.; Frankfurt, L.L.

1981-01-01

Earlier work showed that the few-nucleon correlation model is useful in calculation of the inclusive production of cumulative particles at high energies. Certain integrated characteristics of doubly inclusive spectra in high-energy processes are investigated and permit direct information to be obtained on the structure of the correlations. Scattering of a high-energy lepton by a light nucleus with production of a cumulative nucleon is studied, with particular attention to the average transverse momentum of the hadrons recorded, and the doubly inclusive cross section averaged over the transverse momenta of the particles emitted in the forward hemisphere. Expressions are obtained for the integrated cross sections

Delta-nucleus dynamics: proceedings of symposium

International Nuclear Information System (INIS)

Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P.

1983-10-01

The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta Δ(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe Δ-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented

Delta-nucleus dynamics: proceedings of symposium

Energy Technology Data Exchange (ETDEWEB)

Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P. (eds.)

1983-10-01

The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta ..delta..(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe ..delta..-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented. (WHK)

Compound nucleus effects in spin-spin cross sections

International Nuclear Information System (INIS)

Thompson, W.J.

1976-01-01

By comparison with recent data, it is shown that spin-spin cross sections for low-energy neutrons may be dominated by a simple compound-elastic level-density effect, independent of spin-spin terms in the nucleon-nucleus optical-model potential. (Auth.)

Calculating TMDs of a large nucleus: Quasi-classical approximation and quantum evolution

Directory of Open Access Journals (Sweden)

Yuri V. Kovchegov

2016-02-01

Full Text Available We set up a formalism for calculating transverse-momentum-dependent parton distribution functions (TMDs of a large nucleus using the tools of saturation physics. By generalizing the quasi-classical Glauber–Gribov–Mueller/McLerran–Venugopalan approximation to allow for the possibility of spin–orbit coupling, we show how any TMD can be calculated in the saturation framework. This can also be applied to the TMDs of a proton by modeling it as a large “nucleus.” To illustrate our technique, we calculate the quark TMDs of an unpolarized nucleus at large-x: the unpolarized quark distribution and the quark Boer–Mulders distribution. We observe that spin–orbit coupling leads to mixing between different TMDs of the nucleus and of the nucleons. We then consider the evolution of TMDs: at large-x, in the double-logarithmic approximation, we obtain the Sudakov form factor. At small-x the evolution of unpolarized-target quark TMDs is governed by BK/JIMWLK evolution, while the small-x evolution of polarized-target quark TMDs appears to be dominated by the QCD Reggeon.

Nucleon-nucleon scattering data

International Nuclear Information System (INIS)

Bystricky, J.; Lehar, F.

1981-01-01

The present review contains a compilation of p-p, n-n, n-p and p-n elastic scattering data, total cross sections for elastic and inelastic nucleon-nucleon processes as well as the slope parameters and the ratios of the real to the imaginary part of the forward scattering amplitude measured at all energies. The data are given in detailed tables with comments on each measurement. Summary tables, nucleon-nucleon kinematics formulae, transformation tables for kinematics, a detailed list of references and an author index complete the paper. (orig.)

Radial excitations in nucleon-nucleon scattering

International Nuclear Information System (INIS)

Silvestre-Brac, B.; Carbonell, J.; Gignoux, C.

1986-01-01

In the non-relativistic constituent quark model, the role of the radial excitations of the nucleon is studied within a resonating group approach of the nucleon-nucleon scattering. It is shown that, rather than the inclusion of new channels, it is important to include mixed-symmetry spin-isospin components in the nucleon wave function. It is also found that during the collision there is no significant deformation of the nucleon. (orig.)

Nucleon-nucleon scattering and different meson exchanges

International Nuclear Information System (INIS)

Osman, A.

1985-10-01

The iterative and noniterative diagrams with different meson exchange are investigated. The α, πβ and πγ meson exchange, (where α=π, rho, σ, ω, eta and delta; β=π, rho, σ and ω; γ=π and rho), are considered. These diagrams are taken to involve the nucleon-nucleon, the nucleon-isobar and the isobar-isobar intermediate states. The diagrams are calculated in momentum space following the noncovariant perturbation theory. The role of each of these diagrams is examined by calculating its contribution to the nucleon-nucleon interaction. The potential model is taken to include one-boson-exchange terms in addition to these diagrams. The nucleon-nucleon scattering phase shifts are described successfully showing the importance of tensor force. The contributions of the different parts are studied in the nucleon-nucleon scattering. (author)

The mechanisms of the hadron-nucleus collision processes and of the hadron-nucleus collision induced nuclear reactions - in the light of experimental data

International Nuclear Information System (INIS)

Strugalski, Z.; Strugalska-Gola, E.

1997-01-01

The mechanisms of the hadron-nucleus collision processes and of the hadron-nucleus collision induced nuclear reactions are described - as experimentally based. The target nuclei are damaged definitely and locally in the collisions and the configurations of the nucleons in them became instable. The configuration must transit into stable stages of the nuclear transition reaction products. The difference between the initial internal energy of the unstable residual nucleus and the total final energy of the stable products of the nuclear transition reaction may be released in some cases

Recent Developments in Neutrino/Antineutrino-Nucleus Interactions

Directory of Open Access Journals (Sweden)

Jorge G. Morfín

2012-01-01

Full Text Available Recent experimental results and developments in the theoretical treatment of neutrino-nucleus interactions in the energy range of 1–10 GeV are discussed. Difficulties in extracting neutrino-nucleon cross sections from neutrino-nucleus scattering data are explained and significance of understanding nuclear effects for neutrino oscillation experiments is stressed. Detailed discussions of the status of two-body current contribution in the kinematic region dominated by quasielastic scattering and specific features of partonic nuclear effects in weak DIS scattering are presented.

Problems of the π meson-nucleus interaction theory

International Nuclear Information System (INIS)

Kopaleishvili, T.I.

1984-01-01

The theory of multiple scattering as applied to PI-meson scattering on nuclei is outlined on the base of optical potential method: first in neglecting the real absorption of a pion by a nucleus and then for the case when this effect is taken into account. The pion interaction with a deuteron is considered both neglecting the pion absorption channel (the relativisitic problem of three bodies) and with account of the absorption channels and pion emission (in this case the problem is solved within the frames of the channel coupling theory for the pion-two nucleus system and the system of two nucleons). Approximate or model solutions to the problem of elastic pion-nuclear scattering primarily in the range of (3.3)-resonance are presented. The formulated theory permits to uniquely describe the observed processes caused by the strong pion interaction with a two-nucleon system

Investigation of the 9B nucleus and its cluster-nucleon correlations

Science.gov (United States)

Zhao, Qing; Ren, Zhongzhou; Lyu, Mengjiao; Horiuchi, Hisashi; Funaki, Yasuro; Röpke, Gerd; Schuck, Peter; Tohsaki, Akihiro; Xu, Chang; Yamada, Taiichi; Zhou, Bo

2018-05-01

In order to study the correlations between clusters and nucleons in light nuclei, we formulate a new superposed Tohsaki-Horiuchi-Schuck-Röpke (THSR) wave function which describes both spatially large spreading and cluster-correlated dynamics of valence nucleons. Using this new THSR wave function, the binding energy of 9B is significantly improved in comparison with our previous studies. We calculate the excited states of 9B and obtain an energy spectrum of 9B which is consistent with the experimental results. This includes the prediction of the first 1 /2+ excited state of 9B which is not yet fixed experimentally. We study the proton dynamics in 9B and find that the cluster-proton correlation plays an essential role for the proton dynamics in the ground state of 9B. Furthermore, we discuss the density distribution of the valence proton with special attention to its tail structure. Finally, the resonance nature of excited states of 9B is illustrated comparing root-mean-square radii between the ground and excited states.

Evaluation of the three-nucleon analyzing power puzzle

International Nuclear Information System (INIS)

Tornow, W.; Witala, H.

1998-01-01

The current status of the three-nucleon analyzing power puzzle is reviewed. Applying tight constraints on the allowed deviations between calculated predictions and accepted values for relevant nucleon-nucleon observables reveals that energy independent correction factors applied to the 3 P j nucleon-nucleon interactions can not solve the puzzle. Furthermore, using the same constraints, charge-independence breaking in the 3 P j nucleon-nucleon interactions can be ruled out as a possible tool to improve the agreement between three-nucleon calculations and data. The study of the energy dependence of the three-nucleon analyzing power puzzle gives clear evidence that the 3 P j nucleon-nucleon interaction obtained from phase-shift analyses and used in potential models are correct above about 25 MeV, i.e., the 3 P j nucleon-nucleon interactions have to be modified only at lower energies in order to solve the three-nucleon analyzing power puzzle, unless new three-nucleon forces can be found that account for the three-nucleon analyzing power puzzle without destroying the beautiful agreement between rigorous three-nucleon calculations and a large body of accurate three-nucleon data. (orig.)

Evaluation of the three-nucleon analyzing power puzzle

Energy Technology Data Exchange (ETDEWEB)

Tornow, W. [Duke Univ., Durham, NC (United States). Dept. of Physics]|[Triangle Univ. Nuclear Lab., Durham, NC (United States); Witala, H. [Uniwersytet Jagiellonski, Cracow (Poland). Inst. Fizyki

1998-07-20

The current status of the three-nucleon analyzing power puzzle is reviewed. Applying tight constraints on the allowed deviations between calculated predictions and accepted values for relevant nucleon-nucleon observables reveals that energy independent correction factors applied to the {sup 3}P{sub j} nucleon-nucleon interactions can not solve the puzzle. Furthermore, using the same constraints, charge-independence breaking in the {sup 3}P{sub j} nucleon-nucleon interactions can be ruled out as a possible tool to improve the agreement between three-nucleon calculations and data. The study of the energy dependence of the three-nucleon analyzing power puzzle gives clear evidence that the {sup 3}P{sub j} nucleon-nucleon interaction obtained from phase-shift analyses and used in potential models are correct above about 25 MeV, i.e., the {sup 3}P{sub j} nucleon-nucleon interactions have to be modified only at lower energies in order to solve the three-nucleon analyzing power puzzle, unless new three-nucleon forces can be found that account for the three-nucleon analyzing power puzzle without destroying the beautiful agreement between rigorous three-nucleon calculations and a large body of accurate three-nucleon data. (orig.) 18 refs.

Neutron scattering from 208Pb at 30.4 and 40.0 MeV and isospin dependence of the nucleon optical potential

Science.gov (United States)

Devito, R. P.; Khoa, Dao T.; Austin, Sam M.; Berg, U. E. P.; Loc, Bui Minh

2012-02-01

Background: Analysis of data involving nuclei far from stability often requires the optical potential (OP) for neutron scattering. Because neutron data are seldom available, whereas proton scattering data are more abundant, it is useful to have estimates of the difference of the neutron and proton optical potentials. This information is contained in the isospin dependence of the nucleon OP. Here we attempt to provide it for the nucleon-208Pb system.Purpose: The goal of this paper is to obtain accurate n+208Pb scattering data and use it, together with existing p+208Pb and 208Pb(p,n)208BiIAS* data, to obtain an accurate estimate of the isospin dependence of the nucleon OP at energies in the 30-60-MeV range.Method: Cross sections for n+208Pb scattering were measured at 30.4 and 40.0 MeV, with a typical relative (normalization) accuracy of 2-4% (3%). An angular range of 15∘ to 130∘ was covered using the beam-swinger time-of-flight system at Michigan State University. These data were analyzed by a consistent optical-model study of the neutron data and of elastic p+208Pb scattering at 45 and 54 MeV. These results were combined with a coupled-channel analysis of the 208Pb(p,n) reaction at 45 MeV, exciting the 0+ isobaric analog state (IAS) in 208Bi.Results: The new data and analysis give an accurate estimate of the isospin impurity of the nucleon-208Pb OP at 30.4 MeV caused by the Coulomb correction to the proton OP. The corrections to the real proton OP given by the CH89 global systematics were found to be only a few percent, whereas for the imaginary potential it was greater than 20% at the nuclear surface. On the basis of the analysis of the measured elastic n+208Pb data at 40 MeV, a Coulomb correction of similar strength and shape was also predicted for the p+208Pb OP at energies around 54 MeV.Conclusions: Accurate neutron scattering data can be used in combination with proton scattering data and (p,n) charge exchange data leading to the IAS to obtain reliable

Proton-proton correlations at small relative momentum in neon-nucleus collisions at E/A=400 and 800 MeV

International Nuclear Information System (INIS)

Dupieux, P.; Alard, J.P.; Augerat, J.; Bastid, N.; Charmensat, P.; Fraysse, L.; Marroncle, J.; Montarou, G.; Parizet, M.J.; Qassoud, D.; Rahmani, A.; Fodor, Z.

1988-01-01

Proton-proton small angle correlations have been measured in neon-nucleus collisions, using the 4π detector Diogene, at 400 and 800 MeV per nucleon incident energies. Values of the size of the emitting region are obtained by comparison with the Koonin formula, taking into account the biases of the apparatus. The dependence of the density of target mass and incident energy is also analysed. (orig.)

Low and intermediate energy pion-nucleus interactions in the cascade-exciton model

International Nuclear Information System (INIS)

Mashnik, S.G.

1993-01-01

A large variety of experimental data on pion-nucleus interactions in the bombarding energy range of 0-3000 MeV, on nucleon-induced pion production and on cumulative nucleon production, when a two-step process of pion production followed by absorption on nucleon pairs within a target is taken into account, are analyzed with the Cascade-Exciton Model of nuclear reactions.Comparison is made with other up-to-date models of these processes. The contributions of different pion absorption mechanisms and the relative role of different particle production mechanisms in these reactions are discussed

Warming up a nucleon

International Nuclear Information System (INIS)

Eletsky, V.L.

1991-01-01

The problem of temperature dependence of nucleon mass is addressed by considering a retarded correlator of two currents with quantum numbers of a nucleon at finite temperature T π in the chiral limit. It is shown that at Euclidean momenta the leading one-loop corrections arise from direct interaction of thermal pions with the currents. A dispersive representation for the correlator shows that this interaction smears the nucleon pole over frequency interval with width ∼ T. This interaction does not change the exponential fall-off of the correlator in Euclidean space but gives an O(T 2 /F π 2 ) contribution to the pre-exponential factor. 11 refs. (author)

Pion production and fragmentation of nuclei in high energy nucleus-nucleus collisions

International Nuclear Information System (INIS)

Oskarsson, A.

1983-01-01

In collisions between nuclei at high energies one can study the behaviour of nuclear matter under extreme conditions, regarding nuclear density and temperature. The Bevalac and the CERN SC beams have been used and nuclear emulsion and scintillation telescopes have measured the reaction products. Collisions at 50A-200A MeV and at 2A GeV have been investigated. Proton spectra from 12 C induced reactions at 85A MeV have been recorded for different targets. Energetic protons at large angles can be assumed to be emitted from a source moving with half the beam velocity and a temperature between 13 and 17 MeV, depending on the target. In collisions between nuclei, pions can be produced below 290A MeV due to the internal Fermi motion of the nucleons. Subthreshold pion production has been studied for 12 C induced reactions at 85A and 75A Mev. The cross-sections are consistent with a quasi-free nucleon-nucleon scattering picture, involving Fermi motion, Pauli blocking and pion reabsorption. 16 C induced reactions in emulsion have been studied at 75A, 175A and 2000A MeV. It is shown that the excitation of the parts of the nuclei which are not overlapping (the spectators) increases with the beam energy. The 16 O projectile frequently breaks up into multiple He fragments. These events are associated with large impact parameters. Central collisions with Ag, Br target at 50A-110A MeV have been analysed separately. It is shown that the momentum transfer to the target nucleus is limited to a value considerably lower than the full momentum transfer in a fusion reactions. Events are observed where there are numerous fragments with 3< Z<8. These multifragmentation events cannot be understood in a thermal approach. (author)

Future prospects in N-nucleus interactions

International Nuclear Information System (INIS)

Moss, J.M.

1983-01-01

A detailed examination of two research areas, polarization observables and antiproton-nucleus reactions, which should have near-term future impact on the understanding of the interaction of medium-energy nucleons in nuclei is made. More speculative future experiments employing cooled beams, double spectrometer systems, and large Q-value, low momentum-transfer reactions are also discussed. 25 references, 4 figures

Bombarding energy dependence of nucleon exchange and energy dissipation in the strongly damped reaction 209Bi + 136Xe

International Nuclear Information System (INIS)

Wilcke, W.W.; Schroeder, W.U.; Huizenga, J.R.; Birkelund, J.R.; Randrup, J.

1980-01-01

Although considerable progress has been achieved in the understanding of strongly damped reactions at energies several MeV/u above the Coulomb barrier, some important experimental results are not yet clearly understood. Among these is the degree of correlation between the nucleon exchange and the large energy losses observed. Experimental evidence suggesting nucleon exchange as described by a one-body model to be the major component of the dissipation mechanism is discussed. It is concluded that the previously unexplained bombarding energy dependence between energy loss and fragment charge dispersion can be understood on the basis of a nucleon exchange model, provided the Pauli exclusion principle is taken into account. No necessity is seen to invoke further energy dissipation mechanisms. 7 figures

NN → NN π: the new frontier in nucleon-nucleon interactions

International Nuclear Information System (INIS)

Silbar, R.R.

1986-01-01

The torch in nucleon-nucleon scattering has been passed to experimental and theoretical studies of pion production. Comparing two unitary models shows that most of the structures predicted for spin observables in NN → NNπ are model independent and roughly in agreement with the data. The contribution of rho- exchange is small, indicating the reaction is largely ''peripheral''. The energy dependence of these isobar models is smooth. The largely unstudied reactions producing neutral and negatively-charged pions show richer structure than positively-charged pion production. 6 refs

On slow particle production in hadron-nucleus interactions

International Nuclear Information System (INIS)

Stenlund, E.; Otterlund, I.

1982-01-01

A model for slow particle production in hadron-nucleus interactions is presented. The model succesfully predicts correlations between the number of knock-on particles and the number of particles associated with the evaporation process as well as correlations with the number of collisions, ν, between the incident hadron and the nucleons inside the target nucleus. The model provides two independent possibilities to determine the number of primary intranuclear collisions, ν, i.e. by its correlation to the number of knock-on particles or to the number of evaporated particles. The good agreement indicates that the model gives an impact-parameter sensitive description of hardron nucleus reactions. (orig.)

On the vector meson dominate hypothesis and the RA = σLA/σTA value in electron-nucleus deep inelastic scattering

International Nuclear Information System (INIS)

Peng Hongan; Liu Lianshou

1986-01-01

It is argued that the longitudinal part of space-like photon in its Breit frame is unable to transform into vector meson. Starting from this argument and adding a small amount of diquark component into the nucleon structure functions in nuclei, the A dependence of the R A = σ L A /σ T A value observed in electron nucleus DIS by the SLAC Group is explained

Isospin Mixing in the Nucleon and 4He and the Nucleon Strange Electric Form Factor

International Nuclear Information System (INIS)

Viviani, M.; Girlanda, L.; Kievsky, A.; Marcucci, L. E.; Rosati, S.; Schiavilla, R.; Kubis, B.; Lewis, R.

2007-01-01

In order to isolate the contribution of the nucleon strange electric form factor to the parity-violating asymmetry measured in 4 He(e-vector,e ' ) 4 He experiments, it is crucial to have a reliable estimate of the magnitude of isospin-symmetry-breaking (ISB) corrections in both the nucleon and 4 He. We examine this issue in the present Letter. Isospin admixtures in the nucleon are determined in chiral perturbation theory, while those in 4 He are derived from nuclear interactions, including explicit ISB terms. A careful analysis of the model dependence in the resulting predictions for the nucleon and nuclear ISB contributions to the asymmetry is carried out. We conclude that, at the low momentum transfers of interest in recent measurements reported by the HAPPEX Collaboration at Jefferson Lab, these contributions are of comparable magnitude to those associated with strangeness components in the nucleon electric form factor

Isospin mixing in the nucleon and He-4 and the nucleon strange electric form-factor

International Nuclear Information System (INIS)

M. Viviani; R. Schiavilla; B. Kubis; R. Lewis; L. Girlanda; A. Kievsky; L.E. Marcucci; S. Rosati

2007-01-01

In order to isolate the contribution of the nucleon strange electric form factor to the parity-violating asymmetry measured in 4 He((rvec e),e(prime)) 4 He experiments, it is crucial to have a reliable estimate of the magnitude of isospin-symmetry-breaking (ISB) corrections in both the nucleon and 4 He. We examine this issue in the present letter. Isospin admixtures in the nucleon are determined in chiral perturbation theory, while those in 4 He are derived from nuclear interactions, including explicit ISB terms. A careful analysis of the model dependence in the resulting predictions for the nucleon and nuclear ISB contributions to the asymmetry is carried out. We conclude that, at the low momentum transfers of interest in recent measurements reported by the HAPPEX collaboration at Jefferson Lab, these contributions are of comparable magnitude to those associated with strangeness components in the nucleon electric form factor

Some applications of the multiple scattering theory to the study of the hadron-nucleus interactions at intermediate energies

International Nuclear Information System (INIS)

Dedonder, J.-P.

1979-01-01

This work is devoted to the study of elastic hadron nucleus scattering. At first, an asymptotic evaluation leads to a closed, analytic expression of the eikonal amplitude. This approximate expression displays the role and the influence of the nuclear paremeters in, e.g., p-nucleus scattering around 1 GeV. Pion-nucleus scattering around the 3-3 resonance is then studied. A 3 body model calculation (pion, bound nucleon and residual nucleus represented by a potential) allows to study the importance of binding effects in this problem dominated by the strong energy dependence of the elementary amplitude. The last part is devoted to the construction in momentum space of a realistic optical potential and its comparison with experimental data. The scalling of π + and π - on neighbouring isotopes should allow the measure of the differences between the proton and neutron distributions in nuclei [fr

Effective nucleon-nucleon t matrix in the (p,2p) reaction

International Nuclear Information System (INIS)

Kudo, Y.; Kanayama, N.; Wakasugi, T.

1989-01-01

The cross sections and the analyzing powers for the /sup 40/Ca(p-arrow-right,2p) reactions at E/sub p/ = 76.1, 101.3, and 200 MeV are calculated in the distorted-wave impulse approximation using the Love-Franey effective nucleon-nucleon interaction. It is shown that the calculated individual contributions of the central, spin-orbit, and tensor parts in the Love-Franey interaction to the cross sections and the analyzing powers strongly depend on the incident proton energies. The spectroscopic factors extracted are consistent with the other reaction studies

Nucleon structure from lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Dinter, Simon

2012-11-13

In this thesis we compute within lattice QCD observables related to the structure of the nucleon. One part of this thesis is concerned with moments of parton distribution functions (PDFs). Those moments are essential elements for the understanding of nucleon structure and can be extracted from a global analysis of deep inelastic scattering experiments. On the theoretical side they can be computed non-perturbatively by means of lattice QCD. However, since the time lattice calculations of moments of PDFs are available, there is a tension between these lattice calculations and the results from a global analysis of experimental data. We examine whether systematic effects are responsible for this tension, and study particularly intensively the effects of excited states by a dedicated high precision computation. Moreover, we carry out a first computation with four dynamical flavors. Another aspect of this thesis is a feasibility study of a lattice QCD computation of the scalar quark content of the nucleon, which is an important element in the cross-section of a heavy particle with the nucleon mediated by a scalar particle (e.g. Higgs particle) and can therefore have an impact on Dark Matter searches. Existing lattice QCD calculations of this quantity usually have a large error and thus a low significance for phenomenological applications. We use a variance-reduction technique for quark-disconnected diagrams to obtain a precise result. Furthermore, we introduce a new stochastic method for the calculation of connected 3-point correlation functions, which are needed to compute nucleon structure observables, as an alternative to the usual sequential propagator method. In an explorative study we check whether this new method is competitive to the standard one. We use Wilson twisted mass fermions at maximal twist in all our calculations, such that all observables considered here have only O(a{sup 2}) discretization effects.

Nucleon structure from lattice QCD

International Nuclear Information System (INIS)

Dinter, Simon

2012-01-01

In this thesis we compute within lattice QCD observables related to the structure of the nucleon. One part of this thesis is concerned with moments of parton distribution functions (PDFs). Those moments are essential elements for the understanding of nucleon structure and can be extracted from a global analysis of deep inelastic scattering experiments. On the theoretical side they can be computed non-perturbatively by means of lattice QCD. However, since the time lattice calculations of moments of PDFs are available, there is a tension between these lattice calculations and the results from a global analysis of experimental data. We examine whether systematic effects are responsible for this tension, and study particularly intensively the effects of excited states by a dedicated high precision computation. Moreover, we carry out a first computation with four dynamical flavors. Another aspect of this thesis is a feasibility study of a lattice QCD computation of the scalar quark content of the nucleon, which is an important element in the cross-section of a heavy particle with the nucleon mediated by a scalar particle (e.g. Higgs particle) and can therefore have an impact on Dark Matter searches. Existing lattice QCD calculations of this quantity usually have a large error and thus a low significance for phenomenological applications. We use a variance-reduction technique for quark-disconnected diagrams to obtain a precise result. Furthermore, we introduce a new stochastic method for the calculation of connected 3-point correlation functions, which are needed to compute nucleon structure observables, as an alternative to the usual sequential propagator method. In an explorative study we check whether this new method is competitive to the standard one. We use Wilson twisted mass fermions at maximal twist in all our calculations, such that all observables considered here have only O(a 2 ) discretization effects.

Nonlinear effect of pion production in collisions of atomic nuclei

International Nuclear Information System (INIS)

Grin', Yu.T.

1982-01-01

The phenomenon of pion production in relativistic nucleon-nucleus and nucleus-nucleus interactions is investigated. The present experimental data are analyzed. It is shown that average multiplicity of pions in the (p, C), (C, C) collision reactions with the momentum p=4.2 GeV/cA and (p, Ar), (Ar, KCl) with the momentum p=2.3 GeV/cA non-linearly depends on the nucleon number. The calculated values of average multiplicity of negative pions per one nucleon of nucleus-pro ectile, probability of pion production and number of nucleon interactions for the investigated reactions are presented as a table. A comparative analysis of average multiplicities of pions per nucleon-participant in the nucleon-nucleus and nucleus-nucleus reactions at the p=2.3 GeV/cA momentum for argon and at the p=4.2 GeV/cA for carbon reveals that decrease of multiplicity by 30-35% is observed in nucleus-nucleus collision. Non-linearity is associated with decrease of effective interaction of each incident nucleon in the collision of nuclei as compared with the number of nucleon interactions in the ''elementary'' nucleon-nucleus reaction. Knock-out of nucleons from the colliding nuclei is the most probable reason for the decrease of the number of interactions

Gross and Fine Structure of Pion Production Excitation Functions in {bold {ital p}}-Nucleus and Nucleus-Nucleus Reactions

Energy Technology Data Exchange (ETDEWEB)

Jakobsson, B.; Berg, M.; Carlen, L.; Elmer, R.; Fokin, A.; Ghetti, R.; Martensson, J.; Noren, B.; Oskarsson, A.; Whitlow, H.J. [Department of Physics, University of Lund, Lund (Sweden); Ekstroem, C.; Ericsson, G.; Romanski, J.; van Veldhuizen, E.J.; Westerberg, L. [The Svedberg Laboratory and Department of Neutron Physics, University of Uppsala, Uppsala (Sweden); Julien, J. [Centre d`Etudes Nucleaires, Saclay (France); Skeppstedt, O. [Department of Physics, Chalmers Institute of Technology, Gothenburg (Sweden); Nyboe, K.; Thorsteinsen, T.F.; Amirelmi, S. [Department of Physics, University of Bergen, Bergen (Norway); Guttormsen, M.; Lo/vho/iden, G. [Department of Physics, University of Oslo, Oslo (Norway); Bellini, V.; Palazzolo, F.; Sperduto, M.L. [Istituto Nazionale di Fisica Nucleare/Laboratorio Nazionale del Sud, University of Catania, Catania (Italy); Bondorf, J.P.; Mishustin, I. [Niels Bohr Institute, Copenhagen (Denmark); Avdeichikov, V. [Joint Institute for Nuclear Research, Dubna (Russia); Lozhkin, O.V.; Murin, Y. [V.G. Khlopin Radium Institute, St.Petersburg (Russia)

1997-05-01

Slow ramping of the CELSIUS storage ring has been utilized to measure the yield of charged pions in proton and heavy ion induced collisions with continuously varying beam energy. Boltzmann-Uehling-Uhlenbeck predictions, including Fermi momenta of nucleons in nuclei, follow the general shape of the p-nucleus excitation functions quite well except for a general overestimation of the backward emission. For heavy ion reactions the calculated yield also falls off faster with decreasing beam energy than the data. No statistically significant narrow resonances are observed. {copyright} {ital 1997} {ital The American Physical Society}

J/$\\psi$ production in proton-nucleus and nucleus-nucleus interactions at the CERN SPS

CERN Document Server

Abreu, M C; Alexa, C; Arnaldi, R; Ataian, M R; Baglin, C; Baldit, A; Bedjidian, Marc; Beolè, S; Boldea, V; Bordalo, P; Borges, G; Bussière, A; Capelli, L; Castanier, C; Castor, J I; Chaurand, B; Chevrot, I; Cheynis, B; Chiavassa, E; Cicalò, C; Claudino, T; Comets, M P; Constans, N; Constantinescu, S; Cortese, P; De Falco, A; De Marco, N; Dellacasa, G; Devaux, A; Dita, S; Drapier, O; Ducroux, L; Espagnon, B; Fargeix, J; Force, P; Gallio, M; Gavrilov, Yu K; Gerschel, C; Giubellino, P; Golubeva, M B; Gonin, M; Grigorian, A A; Grossiord, J Y; Guber, F F; Guichard, A; Gulkanian, H R; Hakobyan, R S; Haroutunian, R; Idzik, M; Jouan, D; Karavitcheva, T L; Kluberg, L; Kurepin, A B; Le Bornec, Y; Lourenço, C; Macciotta, P; MacCormick, M; Marzari-Chiesa, A; Masera, M; Masoni, A; Monteno, M; Musso, A; Petiau, P; Piccotti, A; Pizzi, J R; Prado da Silva, W L; Prino, F; Puddu, G; Quintans, C; Ramello, L; Ramos, S; Rato-Mendes, P; Riccati, L; Romana, A; Santos, H; Saturnini, P; Scalas, E; Scomparin, E; Serci, S; Shahoyan, R; Sigaudo, F; Silva, S; Sitta, M; Sonderegger, P; Tarrago, X; Topilskaya, N S; Usai, G L; Vercellin, Ermanno; Villatte, L; Willis, N

2002-01-01

The NA38 and NA50 experiments at the CERN SPS have measured charmonium production in different colliding systems with the aim of observing a phase transition from ordinary hadronic matter towards a state in which quarks and gluons are deconfined (quark-gluon plasma, QGP). This experimental research is based on the prediction that the J/ psi yield should be suppressed in deconfined matter. The analysis of the data collected by the NA50 experiment with Pb-Pb collisions at 158 GeV/c per nucleon shows that the J/ psi is anomalously suppressed with respect to the pattern observed in proton-nucleus and light ion reactions. (9 refs).

Calculations of nucleus-nucleus microscopic optical potentials at intermediate energies

International Nuclear Information System (INIS)

Hanna, K.M.; Kuhtina, I.N.; Lukyanov, K.V.; Lukyanov, V.K.; Zemlyanaya, E.V.; Slowinski, B.

2006-01-01

Three types of microscopic nucleus-nucleus optical potentials are constructed using three patterns for their real and imaginary parts. Two of these patterns are the real V H and imaginary W H parts of the potential which reproduces the high-energy amplitude of scattering in the microscopic Glauber-Sitenko theory. Another template VDF is calculated within the standard double-folding model with the exchange term included. For either of the three tested potentials, the contribution of real and imaginary patterns is adjusted by introducing two fitted factors. Correspondingly, using numerical code ECIS, the elastic differential cross-sections were fitted to the experimental data on scattering of the 16,17 O heavy-ions at about hundred Mev/nucleon on various target-nuclei. The relativization effect is also included. The tables of the obtained factors which renormalize the strengths of the real and (or) imaginary parts of the calculated microscopic potentials are given

Nucleon-nucleon correlations in dense nuclear matter

International Nuclear Information System (INIS)

Alm, T.

1993-02-01

In this thesis new results on the problematics of the formation of nucleon-nucleon correlations in nuclear matter could be presented. Starting from a general study of the two-particle problem in matter we studied the occurrence of a suprafluid phase (pair condensate of nucleons). The Gorkov decoupling by means of anomalous Green functions was generalized, so that also Cooper pairs with spin 1 (triplet pairing) can be described. A generalized gap equation resulted, which permits to determine the order parameters of the suprafluied phase in arbitrary channels of the nucleon-nucleon scattering states. This equation was solvd in the 1 S 0 -, in the 3 P 2 - 3 F 2 , and in the 3 S 1 - 3 D 1 channel under application of realistic nucleon-nucleon potentials. The behaviour of the resulting gap parameters in the single channels was studied as function of density and temperature. (orig.) [de

The momentum distribution inside nucleus

International Nuclear Information System (INIS)

Fujita, T.

1985-01-01

Discussions are made on several reactions which can determine the momentum distribution inside nucleus. The first reaction discussed is the high energy heavy ion collision. This reaction involves many nucleons which interact strongly. Therefore, one must be careful for any possible final state interactions. The expression for the single particle momentum distribution is given. And it can be said that the expression is consistent with the description of the energetic neutrons from muon capture by heavy nucleus. The best way to determine the momentum distribution would be the lepton-nucleus scattering since it does not involve the strong interaction in the initial channel. Another reaction discussed is the backward proton production, which is governed by quite complicated reaction processes. Therefore, the determination of the momentum distribution is only indirect. Noverthless, it is found that this reaction presents a very interesting and important information on the momentum distribution. (Aoki, K.)

Few-Nucleon Research at TUNL: Probing Two- and Three-Nucleon Interactions with Neutrons

Science.gov (United States)

Howell, C. R.; Tornow, W.; Witała, H.

2016-03-01

The central goal of few-nucleon research at the Triangle Universities Nuclear Laboratory (TUNL) is to perform measurements that contribute to advancing ab-initio calculations of nuclear structure and reactions. The program aims include evaluating theoretical treatments of few-nucleon reaction dynamics through strategically comparing theory predictions to data, determining properties of the neutron-neutron interaction that are not accessible in two-nucleon reactions, and searching for evidence of longrange features of three-nucleon interactions, e.g., spin and isospin dependence. This paper will review studies of three- and four-nucleon systems at TUNL conducted using unpolarized and polarized neutron beams. Measurements of neutron-induced reactions performed by groups at TUNL over the last six years are described in comparison with theory predictions. The results are discussed in the context of the program goals stated above. Measurements of vector analyzing powers for elastic scattering in A=3 and A=4 systems, differential cross sections for neutron-deuteron elastic scattering and neutrondeuteron breakup in several final-state configurations are described. The findings from these studies and plans for the coming three years are presented in the context of worldwide activities in this front, in particular, research presented in this session.

Nucleon-deuteron scattering with Δ-isobar excitation: Perturbation theory

International Nuclear Information System (INIS)

Deltuva, A.; Chmielewski, K.; Sauer, P.U.

2003-01-01

A perturbative approach for the description of elastic and inelastic nucleon-deuteron scattering is developed. Its validity is discussed. The aim of the perturbative approach is the isolation of details of different reaction mechanisms. The dynamics is based on a two-baryon potential allowing for the excitation of a nucleon to a Δ isobar. The coupled-channel potential yields an effective three-nucleon force in three-nucleon scattering. The purely nucleonic reference potential is the charge-dependent CD-Bonn potential

Limits on Spin-Dependent WIMP-Nucleon Cross Section Obtained from the Complete LUX Exposure

Science.gov (United States)

Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fallon, S. R.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Velan, V.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

2017-06-01

We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129.5 kg yr exposure acquired by the Large Underground Xenon experiment (LUX), operating at the Sanford Underground Research Facility in Lead, South Dakota (USA). A profile likelihood ratio analysis allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σn=1.6 ×10-41 cm2 (σp=5 ×10-40 cm2 ) at 35 GeV c-2 , almost a sixfold improvement over the previous LUX spin-dependent results. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

One-Boson Approach to Dilepton Production in Nucleon-Nucleon Collisions.

Science.gov (United States)

Haglin, Kevin Lee

1990-01-01

We calculate energy dependent nucleon-nucleon total elastic cross sections and invariant mass dependent electron-positron pair production differential cross sections for the processes pp to pp, np to np and pp to ppe ^+e^-, pn to pne^+e ^- at laboratory kinetic energies in the 1-5 GeV range. These calculations will be based on relativistic quantum field theory in the one-boson-exchange (pi,rho,omega,sigma,delta, eta) approximation to the nucleon-nucleon scattering problem. There are several independent Feynman diagrams for each process--twenty-five for the case np to npe^+e^ - and forty-eight for the case pp to ppe^+e^- --which, for evaluation, require taking the trace of as many as ten gamma matrices and evaluating an angular integral of a quotient of polynomial functions of initial and final energies, particle masses, coupling constants and so on. These mathematical operations are carried out with the aid of the following algebraic manipulators: for the trace operations we use REDUCE 3.3 on the VAX at the ACS facility and for testing the angular integration algorithms we use MAPLE on the Cray-2 at the Minnesota Supercomputer Institute. Finally, we use Cray-2 Fortran for the resulting numerical substitutions. Gauge invariance is strictly observed while including strong and electromagnetic form factors. The numerical results for these calculations are compared with existing data from the Particle Data Group Booklet and compared with recently released data from the Dilepton Spectrometer (DLS) at the Bevalac of proton on Beryllium. For the latter comparison, the spectrometer's finite acceptance function is introduced before a rapidity and transverse momentum integration.

Effect of in-medium nucleon-nucleon cross section on proton-proton momentum correlation in intermediate-energy heavy-ion collisions

Science.gov (United States)

Wang, Ting-Ting; Ma, Yu-Gang; Zhang, Chun-Jian; Zhang, Zheng-Qiao

2018-03-01

The proton-proton momentum correlation function from different rapidity regions is systematically investigated for the Au + Au collisions at different impact parameters and different energies from 400 A MeV to 1500 A MeV in the framework of the isospin-dependent quantum molecular dynamics model complemented by the Lednický-Lyuboshitz analytical method. In particular, the in-medium nucleon-nucleon cross-section dependence of the correlation function is brought into focus, while the impact parameter and energy dependence of the momentum correlation function are also explored. The sizes of the emission source are extracted by fitting the momentum correlation functions using the Gaussian source method. We find that the in-medium nucleon-nucleon cross section obviously influences the proton-proton momentum correlation function, which is from the whole-rapidity or projectile or target rapidity region at smaller impact parameters, but there is no effect on the mid-rapidity proton-proton momentum correlation function, which indicates that the emission mechanism differs between projectile or target rapidity and mid-rapidity protons.

Antiproton-nucleus inelastic scattering and the spin-isospin dependence of the N anti N interaction

International Nuclear Information System (INIS)

Dover, C.B.

1985-01-01

A general overview of the utility of antinucleon (anti N)-nucleus inelastic scattering studies is presented, emphasizing both the sensitivity of the cross sections to various components of the N anti N transition amplitudes and the prospects for the exploration of some novel aspects of nuclear structure. We start with an examination of the relation between NN and N anti N potentials, focusing on the coherences predicted for the central, spin-orbit and tensor components, and how these may be revealed by measurements of two-body spin observables. We next discuss the role of the nucleus as a spin and isospin filter, and show how, by a judicious choice of final state quantum numbers (natural or unnatural parity states, isospin transfer ΔT=0 or 1) and momentum transfer q, one can isolate different components of the N anti N transition amplitude. Various models for the N anti N interaction which give reasonable fits to the available two-body data are shown to lead to strikingly different predictions for certain spin-flip nuclear transitions. We suggest several possible directions for future anti N-nucleus inelastic scattering experiments at LEAR, for instance the study of spin observables which would be accessible with polarized anti N beams, charge exchange reactions, and higher resolution studies of the (anti p, anti p') reaction. We compare the antinucleon and the nucleon as a probe of nuclear modes of excitation. 34 refs

In-medium short-range dynamics of nucleons: Recent theoretical and experimental advances

Energy Technology Data Exchange (ETDEWEB)

Atti, Claudio Ciofi degli, E-mail: ciofi@pg.infn.it

2015-08-14

The investigation of in-medium short-range dynamics of nucleons, usually referred to as the study of short-range correlations (SRCs), is a key issue in nuclear and hadronic physics. As a matter of fact, even in the simplified assumption that the nucleus could be described as a system of protons and neutrons interacting via effective nucleon–nucleon (NN) interactions, several non trivial problems arise concerning the description of in-medium (NN short-range dynamics, namely: (i) the behavior of the NN interaction at short inter-nucleon distances in medium cannot be uniquely constrained by the experimental NN scattering phase shifts due to off-shell effects; (ii) by rigorous renormalization group (RG) techniques entire families of phase equivalent interactions differing in the short-range part can be derived; (iii) the in-medium NN interaction may be, in principle, different from the free one; (iv) when the short inter-nucleon separation is of the order of the nucleon size, the question arises of possible effects from quark and gluon degrees of freedom. For more than fifty years, experimental evidence of SRCs has been searched by means of various kinds of nuclear reactions, without however convincing results, mainly because the effects of SRCs arise from non observable quantities, like, e.g., the momentum distributions, and have been extracted from observable cross sections where short- and long-range effects, effects from nucleonic and non nucleonic degrees of freedom, and effects from final state interaction, could not be unambiguously separated out. Recent years, however, were witness of new progress in the field: from one side, theoretical and computational progress has allowed one to solve ab initio the many-nucleon non relativistic Schrödinger equation in terms of realistic NN interactions, obtaining realistic microscopic wave functions, unless the case of parametrized wave functions used frequently in the past, moreover the development of advanced

On the imaginary part of the S-wave pion-nucleus optical potential

International Nuclear Information System (INIS)

Germond, J.F.; Lombard, R.J.

1991-01-01

The contribution of pion absorption to the imaginary part of the S-wave pion-nucleus optical potential is calculated with Slater determinantal antisymmetrized nuclear wave funtions, taking fully into accout the spin and isospin degrees of freedom. The potential obtained has an explicit dependence on the proton and neutron nuclear densities whose coefficients are directly related to the two-nucleon absorption coupling constants. The values of these coefficients extracted from mesic atoms data are in good agreement with those deduced from exclusive pion absorption experiments in 3 He, but larger than the predictions of the pion rescattering model. (orig.)

P-odd effects observed in the reactions with neutrons and isospin structure of weak nucleon-nucleon interaction

International Nuclear Information System (INIS)

Smotritskij, L.M.

2001-01-01

Application of resonance phase for two quasi-stationary states with similar spin and unlike parity is shown to enable to coordinate the experimentally observed signed dependence of P-odd effects in neutron reactions with the theory. The developed approach enables to obtain information on isospin structure of a weak nucleon-nucleon interaction [ru

The nucleon spin crisis bible

International Nuclear Information System (INIS)

Close, F.E.

1993-06-01

When the new data on polarised lepton nucleon scattering are compared at the same value of Q 2 and with a common set of assumptions, a consistent picture of the spin content of the nucleon begins to emerge. Higher order effects in O(α s ), higher twist effects, modern data on unpolarised structure functions and an updated value for F/D are all important in analysing the data. The detailed x dependences of the polarisation asymmetry in the valence quark region are shown to confirm 20 year old predictions of the quark model and I argue that these are an important ingredient in decoding the nucleon spin puzzle. (author)

The nucleon spin crisis bible

International Nuclear Information System (INIS)

Close, F.E.

1994-01-01

When the new data on polarised lepton nucleon scattering are compared at the same value of Q 2 and with a common set of assumptions, a consistent picture of the spin content of the nucleon begins to emerge. Higher order effects in 0(α s ), higher twist effects, modern data on unpolarized structure functions and an updated value for F/D are all important in analysing the data. The detailed x dependences of the polarisation asymmetry in the valence quark region are shown to confirm 20 year old predictions of the quark model and I argue that these are an important ingredient in decoding the nucleon spin puzzle. (author)

The nucleon spin crisis bible

Energy Technology Data Exchange (ETDEWEB)

Close, F.E.

1993-06-01

When the new data on polarised lepton nucleon scattering are compared at the same value of Q{sup 2} and with a common set of assumptions, a consistent picture of the spin content of the nucleon begins to emerge. Higher order effects in O({alpha}{sub s}), higher twist effects, modern data on unpolarised structure functions and an updated value for F/D are all important in analysing the data. The detailed x dependences of the polarisation asymmetry in the valence quark region are shown to confirm 20 year old predictions of the quark model and I argue that these are an important ingredient in decoding the nucleon spin puzzle. (author).

Internal spin structure of the nucleon

International Nuclear Information System (INIS)

Hughes, V.W.; Kuti, J.

1983-01-01

The study of the structure of the proton and neutron through deep inelastic scattering, initially with electrons but subsequently with muons and neutrinos as well, has played a central role in establishing the quark-parton theory of the composition of hadrons and of quantum chromodynamics (QCD). One important aspect of these theoretical and experimental developments is the two spin-dependent structure functions, which are independent of the two spin-averaged structure functions and define the internal spin structure of the nucleon. Since both quarks and gluons possess spin and the forces between them are spin dependent, we can expect important information on these forces and on nucleon structure to be obtained through the study of the spindependent aspects of the nucleon wave function, as has been the case before in atomic and nuclear physics

Multifragmentation in peripheral nucleus-nucleus collisions

International Nuclear Information System (INIS)

Trautmann, W.; Adloff, J.C.; Bouissou, P.; Hubele, J.; Imme, G.; Iori, I.; Kreutz, P.; Leray, S.; Lindenstruth, V.; Liu, Z.; Lynen, U.; Meijer, R.J.; Milkau, U.; Moroni, A.; Mueller, W.F.J.; Ngo, C.; Ogilvie, C.A.; Pochodzalla, J.; Raciti, G.; Rudolf, G.; Schuettauf, A.; Stuttge, L.

1993-10-01

The complete fragmentation of highly excited nuclear systems into fragments of intermediate mass is observed in heavy-ion reactions at relativistic bombarding energies in the range of several hundreds of MeV per nucleon. Similar features are found for peripheral collisions between heavy nuclei and for more central collisions between a heavy and a light nucleus. The partition space explored in multifragment decays is well described by the statistical multifragmentation models. The expansion before breakup is confirmed by the analysis of the measured fragment energies of ternary events in their own rest frame. Collective radial flow is confined to rather small values in these peripheral-type reactions. Many conceptually different models seem to be capable of reproducing the charge correlations measured for the multifragment decays. (orig.)

Parity violation in the compound nucleus

International Nuclear Information System (INIS)

Bowman, J.D.; Frankle, C.M.; Green, A.A.

1994-01-01

The status of parity violation in the compound nucleus is reviewed. The results of previous experimental results obtained by scattering polarized epithermal neutrons from heavy nuclei in the 3-p and 4-p p-wave strength function peaks are presented. Experimental techniques are presented. The extraction of the mean squared matrix element of the parity-violating interaction, M 2 , between compound-nuclear levels and the relationship of M 2 to the coupling strengths in the meson exchange weak nucleon-nucleon potential are discussed. The tendency of measured asymmetries to have a common sign and theoretical implications are discussed. New experimental results are presented that show that the common sign phenomenon is not universal, as theoretical models developed up to now would predict

Quenching of weak interactions in nucleon matter

International Nuclear Information System (INIS)

Cowell, S.; Pandharipande, V.R.

2003-01-01

We have calculated the one-body Fermi and Gamow-Teller charge-current and vector and axial-vector neutral-current nuclear matrix elements in nucleon matter at densities of 0.08, 0.16, and 0.24 fm -3 and proton fractions ranging from 0.2 to 0.5. The correlated states for nucleon matter are obtained by operating on Fermi-gas states by a symmetrized product of pair correlation operators determined from variational calculations with the Argonne-v18 and Urbana-IX two- and three-nucleon interactions. The squares of the charge- current matrix elements are found to be quenched by 20-25 % by the short-range correlations in nucleon matter. Most of the quenching is due to spin-isospin correlations induced by the pion exchange interactions which change the isospins and spins of the nucleons. A large part of it can be related to the probability for a spin-up proton quasiparticle to be a bare spin-up/down proton/neutron. Within the interval considered, the charge-current matrix elements do not have significant dependence on the matter density, proton fraction, and magnitudes of nucleon momenta; however, they do depend on momentum transfer. The neutral-current matrix elements have a significant dependence on the proton fraction. We also calculate the matrix elements of the nuclear Hamiltonian in the same correlated basis. These provide relatively mild effective interactions that give the variational energies in the Hartree-Fock approximation. The calculated two-nucleon effective interaction describes the spin-isospin susceptibilities of nuclear and neutron matter fairly accurately. However terms greater than or equal to three-body terms are necessary to reproduce the compressibility. Realistic calculations of weak interaction rates in nucleon matter can presumably be carried out using the effective operators and interactions studied here. All presented results use the simple two-body cluster approximation to calculate the correlated basis matrix elements. This allows for a clear

Insights into nucleon structure from parton distributions

Energy Technology Data Exchange (ETDEWEB)

Melnitchouk, Wally [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2017-05-01

We review recent progress in understanding the substructure of the nucleon from global QCD analysis of parton distribution functions (PDFs). New high-precision data onW-boson production in p ¯ p collisions have significantly reduced the uncertainty on the d=u PDF ratio at large values of x, indirectly constraining models of the medium modification of bound nucleons. Drell-Yan data from pp and pd scattering reveal new information on the d¯-u¯ asymmetry, clarifying the role of chiral symmetry breaking in the nucleon. In the strange sector, a new chiral SU(3) analysis finds a valence-like component of the strange-quark PDF, giving rise to a nontrivial s- ¯ s asymmetry at moderate x values. We also review recent analyses of charm in the nucleon, which have found conflicting indications of the size of the nonperturbative charm component.

Transverse energy and neutral pion spectra obtained from 16O- and 32S-induced reactions at 200 GeV/nucleon

International Nuclear Information System (INIS)

Plasil, F.; Albrecht, R.; Awes, T.C.

1989-01-01

The main goal of the CERN heavy-ion experiments is the search for an indication that the predicted state of deconfined quarks and gluons, the quark-gluon plasma (QGP), has been produced. The most promising indication that this may, in fact, be the case comes from the NA38 dimuon measurements, which are focused on the question of J//psi/ suppression. This effect was predicted to be one of the signatures of QGP formation before any measurements were made, and it is the subject of the two other talks at this conference that deal with nucleus-nucleus reactions at ultrarelativistic energies. In this presentation we consider the general (global) features of heavy-ion reactions at CERN energies, and we examine the degree to which they differ from mere superpositions of nucleon-nucleon collisions. We discuss the present status of our data analysis and our main conclusions from the first round of CERN experiments with emphasis on transverse energy measurements, on attained energy densities, and on the spectra of produced neutral pions. Because of time limitations we will not discuss our measurements of distributions of charged particles and the analysis of these distributions in terms of fluctuations nor the results that we have obtained with the Plastic Ball on the behavior of target spectator matter. 20 refs., 5 figs

EMC effect, antishadowing, and pointlike configurations in nucleons

International Nuclear Information System (INIS)

Strikman, M.I.; Frankfurt, L.L.

1985-01-01

Antishadowing of valence-quark distributions in a nucleus is estimated for small x. It is shown that the probability of pointlike configurations is suppressed in a bound nucleon. The possible relation of these phenomena to the EMC effect is discussed. Experiments are proposed to search for pointlike configurations in hadrons. Indications are obtained of the existence of an effect analogous to the EMC effect for x>0.3 in near-threshold eD scattering studied at SLAC

Few-Nucleon Research at TUNL: Probing Two- and Three-Nucleon Interactions with Neutrons

Directory of Open Access Journals (Sweden)

Howell C.R.

2016-01-01

Full Text Available The central goal of few-nucleon research at the Triangle Universities Nuclear Laboratory (TUNL is to perform measurements that contribute to advancing ab-initio calculations of nuclear structure and reactions. The program aims include evaluating theoretical treatments of few-nucleon reaction dynamics through strategically comparing theory predictions to data, determining properties of the neutron-neutron interaction that are not accessible in two-nucleon reactions, and searching for evidence of longrange features of three-nucleon interactions, e.g., spin and isospin dependence. This paper will review studies of three- and four-nucleon systems at TUNL conducted using unpolarized and polarized neutron beams. Measurements of neutron-induced reactions performed by groups at TUNL over the last six years are described in comparison with theory predictions. The results are discussed in the context of the program goals stated above. Measurements of vector analyzing powers for elastic scattering in A=3 and A=4 systems, differential cross sections for neutron-deuteron elastic scattering and neutrondeuteron breakup in several final-state configurations are described. The findings from these studies and plans for the coming three years are presented in the context of worldwide activities in this front, in particular, research presented in this session.

Study of the baryon-baryon interaction in nucleon-nucleon and pion-deuteron scattering

International Nuclear Information System (INIS)

Fuchs, M.

1993-01-01

After the definition of the Hamiltonian in general form by meson production and absorption the transition to operators pursued, which connect only spaces with definite meson numbers. In this approximation first the self-energy of a single baryon was calculated in its full energy and momentum dependence. Then the formal expressions for the T matrices of nucleon-nucleon and pion-deuteron scattering were derived. The essential components of these expressions are the baryon-baryon T matrix ant transition amplitudes from pion-deuteron channels to baryon-baryon states. The central chapter dealt with the calculation of the baryon-baryon interaction for the general form of the vertices, with the solution of the binding problem and the baryon-baryon T matrix. Finally followed the results on the nucleon-nucleon and pion-deuteron scattering. For this first the transition amplitudes from pion-deuteron states to intermediate baryon-baryon states and the Born graphs of the pion-deuteron scattering had to be calculated. After some remarks to the transition from partial-wave decomposed T matrices to scattering observables an extensive representation of the total, partial, and differential cross sections and a series of spin observables (analyzing powers and spin correlations) for the elastic proton-proton, neutron-proton, and pion-deuteron scattering as well for the fusion reaction pp→πd and the breakup reaction πd→pp follows. Thereby the energies reached from the nucleon-nucleon respectively pion-deuteron threshold up to 100 MeV above the delta resonance

Energy loss, range and fluence distributions, total reaction and projectile fragment production cross sections for proton-nucleus and nucleus-nucleus interactions

International Nuclear Information System (INIS)

Sihver, L.; Kanai, T.

1992-07-01

We have developed a computer code for calculations of energy loss (dE/dx) and range distributions for heavy ions in any media. The results from our calculations are in very good agreement with previous calculations. We have developed semiempirical total reaction cross section formulae for proton-nucleus (with Z p ≤26) and nucleus-nucleus (with Z p and Z t ≤26) reactions. These formulae apply for incident energies above 15 MeV and 100 MeV/nucleon respectively. From the total reaction cross sections, we can calculate the mean free paths and the fluence distributions of protons and heavy ions in any media. We have compared all the calculated reaction cross sections and the mean free paths with experimental data, and the agreement is good. We have also constructed a procedure for calculating projectile fragment production cross sections, by scaling semiempirical proton-nucleus partial cross section systematics. The scaling is performed using a scaling parameter deduced from our reaction cross sections formulae, and additional enhancements factors. All products with atomic number ranging from that of the projectile (Z p ) down to Z=2 can be calculated. The agreement between the calculated cross sections and the experimental data is better than earlier published results. (author)

The effect of higher order different meson exchange nucleon-nucleon interactions on the three-nucleon binding energy coupling problem

International Nuclear Information System (INIS)

Osman, A.; Ramadan, S.

1989-01-01

Faddeev equations of bound three-nucleon system are presented as a set of integral equations. To solve them, a sutable form of the nucleon-nucleon interactions is used: with the exchange of a scalar meson, a pseudoscalar meson and a massless vector meson. Higher orders of these different meson exchanges in the nucleon-nucleon interactions have been taken into account. With these nuclear forces and nucleon-nucleon interactions, the three-nucleon binding energy is calculated by solving the Faddeev integral equations. The obtained value of the three-nucleon binding energy is 8.441 MeV. The inclusion of the higher order terms of the different meson exchange in the nuclear nucleon-nucleon interaction is found to affect the three-nucleon binding by about 3.92%. 3 figs., 16 refs

Multiquark states in the deep inelastic muon-nucleus scattering

International Nuclear Information System (INIS)

Titov, A.I.

1983-01-01

The deep-inelastic muon-nucleus scattering in the region forbidden by the kinematics for the scattering on free nucleons, is analysed theoretically. The calculations have been performed under the assumption that the main contribution to the cross section in the considered region of the Bjorken scaling variable, 1 -4 -10 -5 for the nuclear structure function at x approximately equal to 1.4. As it is shown, one has to take into account the six-= ' quark states in extracting the scaling parameter of QCD from the muon-nucleus data at approximately 1

Some preliminary considerations on antiproton-nucleus experiments

International Nuclear Information System (INIS)

Yavin, A.I.

1981-05-01

The antiproton as a probe of the atomic nucleus is discussed in the expectation that fairly intense beams of high quality will be available in 1983 at the Low Energy Antiproton Ring (LEAR) facility at CERN and possibly also in some other laboratories at a later date. Several antiproton-nucleus experiments are proposed, and the possibility of observing antiprotonic nuclei as well as antineutronic nuclei is discussed. It is demonstrated that even for the study of the elementary nucleon-antinucleon systems it could be advantageous to use nuclei rather than protons as target. The possibility of investigating several antiprotonic atomic systems is also briefly discussed [fr

Weak interaction and nucleus: the relationship keeps on

International Nuclear Information System (INIS)

Martino, J.; Frere, J.M.; Naviliat-Cuncic, O.; Volpe, C.; Marteau, J.; Lhuillier, D.; Vignaud, D.; Legac, R.; Marteau, J.; Legac, R.

2003-01-01

This document gathers the lectures made at the Joliot-Curie international summer school in 2003 whose theme, that year, was the relationship between weak interaction and nucleus. There were 8 contributions whose titles are: 1) before the standard model: from beta decay to neutral currents; 2) the electro-weak theory and beyond; 3) testing of the standard model at low energies; 4) description of weak processes in nuclei; 5) 20.000 tonnes underground, an approach to the neutrino-nucleus interaction; 6) parity violation from atom to nucleon; 7) how neutrinos got their masses; and 8) CP symmetry

Field theoretical approach to proton-nucleus reactions. I - One step inelastic scattering

International Nuclear Information System (INIS)

Eiras, A.; Kodama, T.; Nemes, M.C.

1988-01-01

In this work we obtain a closed form expression to the double differential cross section for one step proton-nucleus reaction within a field theoretical framework. Energy and momentum conservation as well as nuclear structure effects are consistently taken into account within the field theoretical eikonal approximation. In our formulation the kinematics of such reaction is not dominated by the free nucleon-nucleon cross section but a new factor which we call relativistic differential cross section in a Born Approximation. (author) [pt

Classically dynamical behaviour of a nucleon in heavy nuclei

International Nuclear Information System (INIS)

Gu Jianzhong; Zhao Enguang; Zong Hongshi; Zhuo Yizhong; Wu Xizhen

1998-01-01

Within the framework of the two-center shell model the classically dynamical behaviour of a nucleon in heavy nuclei is investigated systematically with the change of nuclear shape parameters for the first time. It is found that as long as the nucleonic energy 0is appreciably higher than the height of the potential barrier there is a good quantum-classical correspondence of nucleonic regular (chaotic) motion. Thus, Bohigas, Giannoni and Schmit conjecture is confirmed once again. We find that the difference between the potential barrier for prolate nuclei and that for oblate ones is reponsible for the energy-dependence difference between the nucleonic chaotic dynamics for prolate nuclei and that for oblate ones. In addition, it is suggested that nuclear dissipation is shape-dependent, and strong nuclear dissipation can be expected for medium or large separations in the presence of a considerable neck deformation built on a pronounced octupole-like deformation, which provides us a dynamical understanding of nuclear shape dependence of nuclear dissipation. (orig.)

The effect of including tensor forces in nucleon-nucleon interaction on three-nucleon binding energy

International Nuclear Information System (INIS)

Osman, A.; Ramadan, S.

1986-01-01

Separable two-body interactions are used in considering the three-nucleon problem. The nucleon-nucleon potentials are taken to include attraction and repulsion as well as tensor forces. The separable approximation is used in order to investigate the effect of the tensor forces. The separable expansion is introduced in the three-nucleon problem, by which the Faddeev equations are reduced to a well-behaved set of coupled integral equations. Numerical calculations are carried out for the obtained integral equations using potential functions of the Yamaguchi, Gaussian, Takabin, Mongan and Reid forms. The present calculated values of the binding energies of the 3 H and 3 He nuclei are in good agreement with the experimental values. The effect of including the tensor forces in the nucleon-nucleon interactions is found to improve the three-nucleon binding energy by about 4.490% to 8.324%. 37 refs., 2 tabs. (author)

Three-nucleon hadronic and electromagnetic reactions with Δ-isobar excitation

International Nuclear Information System (INIS)

Deltuva, A.; Adam, J. Jr.; Fonseca, A.C.; Sauer, P.U.

2005-01-01

Three-nucleon hadronic and electromagnetic reactions are described. The description uses the purely nucleonic charge-dependent CD-Bonn potential and its coupled-channel extension CD-Bonn + Δ. Exact solutions of three-particle equations are employed for the initial and final states of the reactions. The Δ-isobar excitation yields an effective three-nucleon force and effective two- and three-nucleon currents beside other Δ-isobar effects; they are mutually consistent

Self-consistent theory of charged current neutrino-nucleus reactions

Energy Technology Data Exchange (ETDEWEB)

Paar, Nils; Marketin, Tomislav; Vretenar, Dario [Physics Department, Faculty of Science, University Zagreb (Croatia); Ring, Peter [Physik-Department, Technischen Universitaet Muenchen, D-85748 Muenchen (Germany)

2009-07-01

A novel theoretical framework has been introduced for description of neutrino induced reactions with nuclei. The properties of target nuclei are determined in a self-consistent way using relativistic mean-field framework based on effective Lagrangians with density dependent meson-nucleon vertex functions. The weak lepton-hadron interaction is expressed in the standard current-current form, the nuclear ground state is described in the relativistic Hartree-Bogolyubov model, and the relevant transitions to excited nuclear states are calculated in the proton-neutron relativistic quasiparticle random phase approximation. This framework has been employed in studies of charged-current neutrino reactions involving nuclei of relevance for neutrino detectors, r-process nuclei, and neutrino-nucleus cross sections averaged over measured neutrino fluxes and supernova neutrino distributions.

Relations between the simultaneous and sequential transfer of two nucleons

International Nuclear Information System (INIS)

Satchler, G.R.

1982-01-01

The transfer of two nucleons between projectile and target in a direct or peripheral reaction such as (p,t) or ( 16 O, 14 C) may occur in one-step or two-steps. These we refer to as simultaneous and sequential transfers, respectively. In the former, the interaction acts once and both nucleons are transferred. In the latter, the interaction acts once to transfer one nucleon, the system then propagates in one or more intermediate states and is followed by a second action of the interaction to transfer the second nucleon. This process may be symbolized for the examples as (p,d; d,t) and ( 16 O, 15 N; 15 N, 14 C), implying the intermediate formation of a deuteron or the nucleus 15 N. In terms of a perturbation theory expansion, such as the distorted-wave Born series, simultaneous transfer is possible in first order while sequential transfer requires second order. The nuclear forces are predominantly two-body in character; hence, in first-order only one of the two nucleons experiences an interaction. The possibility of finding that the other nucleon has also transferred arises only because its state within the projectile is not orthogonal to the state in the target into which it transfers. In the two-step process each nucleon is transferred under the direct influence of an interaction with the target. The one-step and two-step amplitudes are frequently comparable in magnitude for light-ion reactions while the two-step may dominate in reactions with heavy ions. Our purpose here is to gain some insight into the relationship between the two amplitudes by using a simple approximate form of the theory. For simplicity, we shall discuss a light-ion reaction and, to be specific, we choose the (t,p) reaction (or the inverse (p,t) reaction)

Theoretical predictions for α -decay chains of 118 290 -298Og isotopes using a finite-range nucleon-nucleon interaction

Science.gov (United States)

Ismail, M.; Adel, A.

2018-04-01

The α -decay half-lives of the recently synthesized superheavy nuclei (SHN) are investigated by employing the density dependent cluster model. A realistic nucleon-nucleon (NN ) interaction with a finite-range exchange part is used to calculate the microscopic α -nucleus potential in the well-established double-folding model. The calculated potential is then implemented to find both the assault frequency and the penetration probability of the α particle by means of the Wentzel-Kramers-Brillouin (WKB) approximation in combination with the Bohr-Sommerfeld quantization condition. The calculated values of α -decay half-lives of the recently synthesized Og isotopes and its decay products are in good agreement with the experimental data. Moreover, the calculated values of α -decay half-lives have been compared with those values evaluated using other theoretical models, and it was found that our theoretical values match well with their counterparts. The competition between α decay and spontaneous fission is investigated and predictions for possible decay modes for the unknown nuclei 118 290 -298Og are presented. We studied the behavior of the α -decay half-lives of Og isotopes and their decay products as a function of the mass number of the parent nuclei. We found that the behavior of the curves is governed by proton and neutron magic numbers found from previous studies. The proton numbers Z =114 , 116, 108, 106 and the neutron numbers N =172 , 164, 162, 158 show some magic character. We hope that the theoretical prediction of α -decay chains provides a new perspective to experimentalists.

Pion-nucleus scatter and the Pauli principle

International Nuclear Information System (INIS)

Dover, C.B.; Lemmer, R.H.

1976-01-01

A density expansion of the pion self-energy for pions in nuclear matter is reexamined. It is shown that a single hole-line expansion of the self-energy (i) is equivalent to using a strongly quenched πN scattering amplitude in the medium, and (ii) results in an inconsistent treatment of the virtual pions necessarily present in a field-theoretic description of the problem. Exchange of intermediate pions gives rise to nucleon-nucleon, as well as pion-nucleon scattering diagrams that both contribute to the pion self-energy in an essential way. The nucleon-nucleon scattering proceeds, for instance, via a one-pion-exchange potential that is, however, highly nonstatic for energy transfers between nucleons close to the incident energy. Such interactions are singled out automatically for special treatment in a field-theory approach to the problem, and should not be introduced in an ad hoc manner as part of an empirical NN interaction in nuclear matter. We evaluate the coherent and charge exchange contributions to the pion-nucleus optical potential, proportional to the total density and the neutron-proton density difference, respectively. The Pauli principle is found to provide a small correction to the coherent part, both in the hole-line and density expansion formalisms. However, the charge exchange part of the potential is almost completely damped at low energies in the hole-line expansion, while the inclusion of backward-going graphs (random-phase-approximation-type correlations) restores it to its value based on free space πN charge exchange amplitudes (i.e., no net Pauli effect)

Parity violation in the nucleon-nucleon interaction

International Nuclear Information System (INIS)

Haxton, W.C.

1989-01-01

I discuss the present status of our understanding of parity nonconservation (PNC) in the nucleon-nucleon interaction, and some of the difficulties inherent in nuclear tests of PNC. I also discuss the nucleon/nuclear anapole moment, the parity violating coupling of the photon, and its relation to the PNC NN interaction. 13 refs., 1 fig., 2 tabs

Possible Existence of (cc¯)–Nucleus Bound States

International Nuclear Information System (INIS)

Yokota, Akira; Oka, Makoto; Hiyama, Emiko

2014-01-01

Charmonium (cc¯) bound states in few-nucleon systems, 2 H, 4 He and 8 Be, are studied via Gaussian Expansion Method (GEM). We adopt a Gaussian potential as an effective (cc¯)–nucleon (N) interaction. The relation between two-body (cc¯)–N scattering length a cc¯−N and the binding energies B of (cc¯)–nucleus bound states are given. Recent lattice QCD data of a cc¯−N corresponds to B≃0.5 MeV for (cc¯)− 4 He and 2 MeV for (cc¯)− 8 Be in our results. (author)

Theoretical advancements and applications of the low-momentum nucleon-nucleon interaction

Science.gov (United States)

Holt, Jason Davidson

calculations with Vlow k can reproduce the key signatures identifying mixed-symmetry states in the prototypical nuclei 94Mo and 92Zr. While observed in numerous even-even nuclei, mixed-symmetry states have never been seen in an odd-mass nearly-spherical nucleus. We present the results of a joint experimental and theoretical study that succeeded in identifying the first states in such a nucleus 93Nb. The shell model calculations not only accurately predict the experimental measurements, but provide essential information necessary to confirm the presence of mixed-symmetry suggested by the experiments. Finally we present the first microscopic predictions for the evolution of MS states through the chain of N=52 isotones, where it is found that the collective MS structures exhibit an illuminating dependence on the underlying microscopic shell structure.

Composite model approach to the 2He4 nucleus ground state

International Nuclear Information System (INIS)

Mehrotra, I.; Agarwal, B.K.

1986-12-01

Assuming that the nucleons are (πμ) composite systems the helium nucleus is compared to a molecule consisting of four hydrogen-like atoms where pions are like nuclei and muons are like electrons. Ground state energy of 2 He 4 nucleus has been estimated in the framework of valence-bond method. Good agreement with the experimental value can be obtained if it is assumed that μ + μ - coupling is 3% stronger than the μ ± μ ± coupling. (author). 11 refs, 1 tab

Exact solution of the nucleons diffusion equation with increase inelastic cross section

International Nuclear Information System (INIS)

Portella, H.M.

1985-01-01

The successive aproximations method is applied to obtain an exact and compact analytical solution of the differential equation wich describes the diffusion of nucleonic component in the atmosphere, when the inelastic cross section of the air interaction nucleon-nucleus increases with the energy. The result is compared with the experimental data wich have been obtained in Chacaltaya (x=540g/cm 2 ) by the Brazil - Japan cooperation using emulsion chambers. The value of the constant a measurement of the variation of the cross section with the energy, that makes the best adjustment of the result found out with the experimental data is between 0.05 and 0.06. (M.C.K.) [pt

Nucleon-nucleon theory and phenomenology. Progress report and renewal proposal

International Nuclear Information System (INIS)

Signell, P.

1981-01-01

Progress is outlined on five inter-related subprojects: (1) derivation of the intermediate range nucleon-nucleon interaction with the new dramatically altered ππ s-wave interaction and using a new method that utilizes much shorter and simpler analytic continuation through the unphysical region that lies between the πN and ππ physical regions of the N anti N → ππ amplitude (with significantly improved accuracy for the nucleon-nucleon interaction); (2) construction of a short range phenomenological potential that, with the theoretical part mentioned above, gives a precise fit to the nucleon-nucleon data and is parameterized for easy use in nucleon calculations; (3) phase shift analyses of the world data below 400 MeV, especially the large amount of very precise data below 20 MeV and the new data near 55 MeV that have never been analyzed properly, and determining which phases are given by theory at which energies; (4) the introduction of our K-matrix formulation of the Optimal Polynomial Expansion in order to accelerate convergence of the partial wave series at LAMPF energies; and (5) setting up of a cooperatively evaluated and verified permanent nucleon-nucleon data bank in the 0 to 1200 MeV range that can be used by all nucleon-nucleon researchers (or anyone else) via Telenet dial-in and by means of a published compendium

Transverse momentum distributions inside the nucleon from lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Musch, Bernhard Ulrich

2009-05-29

Nucleons, i.e., protons and neutrons, are composed of quarks and gluons, whose interactions are described by the theory of quantum chromodynamics (QCD), part of the standard model of particle physics. This work applies lattice QCD to compute quark momentum distributions in the nucleon. The calculations make use of lattice data generated on supercomputers that has already been successfully employed in lattice studies of spatial quark distributions (''nucleon tomography''). In order to be able to analyze transverse momentum dependent parton distribution functions, this thesis explores a novel approach based on non-local operators. One interesting observation is that the transverse momentum dependent density of polarized quarks in a polarized nucleon is visibly deformed. A more elaborate operator geometry is required to enable a quantitative comparison to high energy scattering experiments. First steps in this direction are encouraging. (orig.)

Nucleon-nucleon optical model for energies to 3 GeV

International Nuclear Information System (INIS)

Funk, A.; Von Geramb, H.V.; University of Melbourne, VIC; Amos, K.A.

2001-01-01

Several nucleon-nucleon potentials, Paris, Nijmegen, Argonne, and those derived by quantum inversion, which describe the NN interaction for T Lab ≤ 300 MeV are extended in their range of application as NN optical models. Extensions are made in r-space using complex separable potentials definable with a wide range of form factor options including those of boundary condition models. We use the latest phase shift analyses SP00 (FA00, WI00) of Arndt et al. from 300 MeV to 3 GeV to determine these extensions. The imaginary parts of the optical model interactions account for loss of flux into direct or resonant production processes. The optical potential approach is of particular value as it permits one to visualize fusion, and subsequent fission, of nucleons when T Lab > 2 GeV. We do so by calculating the scattering wave functions to specify the energy and radial dependences of flux losses and of probability distributions. Furthermore, half-off the energy shell t-matrices are presented as they are readily deduced with this approach. Such t-matrices are required for studies of few- and many-body nuclear reactions

Nucleus-nucleus collisions at 60 to 200 GeV/nucleon: Photon measurement results from the WA80 experiment at CERN

International Nuclear Information System (INIS)

1990-11-01

Photon measurement results from 16 O+ 197 Au reactions at 200 GeV/nucleon obtained by the WA80 collaboration at the CERN SPS are presented. Transverse momentum spectra of neutral pions and of direct photons are shown. At an accuracy within 15% limits, all observed photons are accounted for by known hadronic decays

On the deep inelastic lepton-nucleus scattering

International Nuclear Information System (INIS)

Darbaidze, Ya.Z.; Garsevanishvili, V.R.; Menteshashvili, Z.R.

1979-01-01

Deep inelastic scattering of charged leptons on nuclei is considered in the lowest order in electromagnetic interaction. Expressions for the corresponding differential cross sections are obtained provided the scattered lepton and the fragment of the initial nucleus are detected in coincidence. Structure functions are analyzed by means of the automodelity principle. These functions are considered in the framework of the ''light front'' formalism for many-body systems. A hypothesis is put forward on the scale invariance of structure functions with respect to the xi-variable, which is some complicated dimensionless combination of kinematic invariants. A simple relation of this variable to the momenta of the nucleons inside the initial nucleus is pointed out

Isospin breaking in the pion-nucleon coupling constant and the nucleon-nucleon scattering length

Directory of Open Access Journals (Sweden)

V. A. Babenko

2016-08-01

Full Text Available Charge independence breaking (CIB in the pion-nucleon coupling constant and the nucleon-nucleon scattering length is considered on the basis of the Yukawa meson theory. CIB effect in these quantities is almost entirely explained by the mass difference between the charged and the neutral pions. Therewith charge splitting of the pion-nucleon coupling constant is almost the same as charge splitting of the pion mass. Calculated difference between the proton-proton and the neutron-proton scattering length in this case comprises ∼90% of the experimental value.

Nucleon structure functions, resonance form factors, and duality

International Nuclear Information System (INIS)

Davidovsky, V.V.; Struminsky, B.V.

2003-01-01

The behavior of nucleon structure functions in the resonance region is explored. For form factors that describe resonance production, expressions are obtained that are dependent on the photon virtuality Q 2 , which have a correct threshold behavior, and which take into account available experimental data on resonance decay. Resonance contributions to nucleon structure functions are calculated. The resulting expressions are used to investigate quark-hadron duality in electron-nucleon scattering by taking the example of the structure function F 2

One-nucleon pickup reactions and compound-nuclear decays

Science.gov (United States)

Escher, J. E.; Burke, J. T.; Casperson, R. J.; Hughes, R. O.; Scielzo, N. D.

2018-05-01

One-nucleon transfer reactions, long used as a tool to study the structure of nuclei, are potentially valuable for determining reaction cross sections indirectly. This is significant, as many reactions of interest to astrophysics and other applications involve short-lived isotopes and cannot be measured directly. We describe a procedure for obtaining constraints for calculations of neutron capture cross sections using observables from experiments with transfer reactions. As a first step toward demonstrating the method, we outline the theory developments used to properly describe the production of the compound nucleus 88Y* via the one-nucleon pickup reaction 89Y(p,d)88Y* and test the description with data from a recent experiment. We indicate how this development can be used to extract the unknown 87Y(n,γ) cross section from 89Y(p,dγ) data. The example illustrates a more generally applicable method for determining unknown cross sections via a combination of theory and transfer (or inelastic scattering) experiments.

General aspects of the nucleon-nucleon interaction and nuclear matter properties

Energy Technology Data Exchange (ETDEWEB)

Plohl, Oliver

2008-07-25

The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are

General aspects of the nucleon-nucleon interaction and nuclear matter properties

International Nuclear Information System (INIS)

Plohl, Oliver

2008-01-01

The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are

Analysis of the nucleon-nucleus reactions by the quantum molecular dynamics

International Nuclear Information System (INIS)

Chiba, Satoshi; Niita, Koji; Maruyama, Toshiki; Fukahori, Tokio; Takada, Hiroshi; Iwamoto, Akira

1995-01-01

The quantum molecular dynamics + statistical decay model has been applied to analyze the nucleon-induced nuclear reactions in the energy range from 50 to 3 GeV in order to verify its applicability to light-ion induced nuclear reactions. It was found that the present approach could give a quantitative description of various cross sections such as (p,p'), (p,n), (n,p) reactions from a wide range of targets and also target-like isotope production cross sections from p+Fe reaction, showing its basic ability as a tool for the study of intermediate energy nuclear reactions and nuclear data evaluation. (author)

Disconnected-Sea Quarks Contribution to Nucleon Electromagnetic Form Factors

Science.gov (United States)

Sufian, Raza Sabbir

We present comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon electric and magnetic form factors. The lattice QCD estimates of strange quark magnetic moment GsM (0) = -0.064(14)(09) microN and the mean squared charge radius E = -0.0043(16)(14) fm2 are more precise than any existing experimental measurements and other lattice calculations. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light-sea and strange quarks contribution to the nucleon magnetic moment is -0.022(11)(09) microN and to the nucleon mean square charge radius is -0.019(05)(05) fm 2. The most important outcome of this lattice QCD calculation is that while the combined light-sea and strange quarks contribution to the nucleon magnetic moment is small at about 1%, a negative 2.5(9)% contribution to the proton charge radius and a relatively larger positive 16.3(6.1)% contribution to the neutron charge radius come from the sea quarks in the nucleon. For the first time, by performing global fits, we also give predictions of the light-sea and strange quarks contributions to the nucleon electric and magnetic form factors at the physical point and in the continuum and infinite volume limits in the momentum transfer range of 0 ≤ Q2 ≤ 0.5 GeV2.

Three-nucleon forces

International Nuclear Information System (INIS)

Sauer, P.U.

2014-01-01

In this paper, the role of three-nucleon forces in ab initio calculations of nuclear systems is investigated. The difference between genuine and induced many-nucleon forces is emphasized. Induced forces arise in the process of solving the nuclear many-body problem as technical intermediaries toward calculationally converged results. Genuine forces make up the Hamiltonian. They represent the chosen underlying dynamics. The hierarchy of contributions arising from genuine two-, three- and many-nucleon forces is discussed. Signals for the need of the inclusion of genuine three-nucleon forces are studied in nuclear systems, technically best under control, especially in three-nucleon and four-nucleon systems. Genuine three-nucleon forces are important for details in the description of some observables. Their contributions to observables are small on the scale set by two-nucleon forces. (author)

Semi-phenomenological model of the nucleon-nucleon interaction

International Nuclear Information System (INIS)

Houriet, A.; Bagnoud, Y.

1977-01-01

A nucleon with isobars is used to elaborate a model of the nucleon-nucleon interaction at low energy (Esub(CM) 2 sub(r), the pion-nucleon renormalized coupling constant. The model establishes a very good coordination for deuteron and p-p scattering-polarization measurements ( 1 K 0 , 1 D 2 , 1 G 4 phase shifts), and permits the determination of f 2 sub(r) for every independent experimental value. For 21 such values, the mean value 2 sub(r)>=0.0785 with Δf 2 sub(r)=0.0024(3%) is obtained. (Auth.)

Spin-dependent Nucleon Structure Studies at MIT/Bates

International Nuclear Information System (INIS)

Botto, T.

2005-01-01

We present preliminary results from recent measurements of the proton, neutron and deuterium electro-magnetic form factors obtained by the BLAST collaboration at the MIT/Bates Linear Accelerator Facility. BLAST (Bates Large Acceptance Spectrometer Toroid) is a large-acceptance multi-purpose detector dedicated to studies of exclusive spin-dependent electron scattering from internal polarized targets. BLAST makes use of stored electron beam currents in excess of 150 mA with a 60-70% polarization. The electron beam is let through a 15 mm diameter, 60 cm long open-ended storage cell which is fed with ultra-pure, high-polarization H1,D1 gas from an Atomic Beam Source. The target polarization can be rapidly reversed between different vector and tensor target states, thus minimizing systematic uncertainties. The target spin can be oriented to any in-plane direction via a set of Helmholtz coils. Target polarizations in the storage cell of up to 80% (vector) and 70% (tensor) have been routinely achieved over a period of several months. Our data on the D-vector(e-vector,e'n) reaction off vector polarized deuterium allow for a unique extraction of the neutron charge form factor G E n . At same time, complementary measurements of G M n , T20 and the spin-dependent nucleon momentum distributions in deuterium are obtained via the D-vector(e-vector,e'), D (e-vector,e'd) and D (e-vector,e'p) reactions. In addition, BLAST data on vector polarized hydrogen will provide novel measurements of the GE/GM form-factor ratio on the proton as well as of the spin-dependent electro-excitation of the Δ(1232) resonance. Such comprehensive program on few body physics is now well underway and preliminary data will be presented

An enlarged superfluid model of atomic nucleus

International Nuclear Information System (INIS)

Dumitrescu, O.; Horoi, M.

1989-01-01

The well known superfluid model (or quasiparticle phonon nuclear model (QPNM)) of atomic nucleus is enlarged by including an adequate four-nucleon effective interaction in addition to the pairing and long-range effective residual interactions. New experimental data can be explained without affecting those observables already described by the QPNM and in addition new features can be enumerated: 1) superfluidities of the neutron and proton systems may be generated by one another; 2) the phase structure is enriched by a new superfluid phase dominated by alpha-type correlations (ATC) and 3) superfluid isomers and their bands of elementary excitations are predicted. Unusual large two-nucleon and alpha transfer reactions cross sections as well as some unusual large alpha decay widths can be explained. (author). 46 refs, 3 figs, 2 tabs

Nucleon-nucleon forces in the quark compound bag model and few-nucleon systems

International Nuclear Information System (INIS)

Kalashnikova, Yu.S.; Narodetskij, I.M.

1984-01-01

Role of quark-gluon degrees of freedom is discussed in nucleon-nucleon scattering at low and intermediate energies. It is shown that the existence of six-quark hags fixes the form of NN potential at small distances, which leads to the P-matrix satisfying the criterion of Jaffe and Low. The dynamical model of three-nucleon system is discussed taking into accoint the contribution of six-quark bags

Dependence of dipole transition gamma ray strength on the type of nucleus

International Nuclear Information System (INIS)

Cojocaru, V.; Stefanescu, Irina; Popescu, I.V.; Badica, T.; Olariu, A.

2000-01-01

The strength of gamma-ray transition is defined as the ratio between the experimental radiative width Γ γ and the theoretical radiative width calculated according to a model (for example Weisskopf single particle model, Γ W ). It is important to know on which parameters this strengths depend. In our previous work we put in evidence the dependence of the dipole transition gamma-ray strengths on the type of the nucleus. In this paper we look for a possible dependence of the quadrupole gamma-ray strengths on the type of nucleus (doubly-even, doubly-odd, with odd proton number and odd neutron number). All the input data are taken from the National Nuclear Data Center, Brookhaven. In order to demonstrate this possible dependence one can use the average of the strongest 10% transitions of given character. As the A dependence is concerned we use the following A-regions: 6-20, 21-44, 45-90, 91-150, 151-200. An average value for these transitions is also plotted both for the E2 and M2 transitions. Generally, all the functions log 10 vs A (S=Γ γ /Γ W ) have the same pattern as 'total' put in evidence by Endt. Moreover, there is a clear difference in the most A regions of the average S 10 values for different types of nuclei. As the RUL (Recommended Upper Limits W.u.) are concerned they have to be established as the highest experimental values of the transition strengths. In this work we suggest new RUL but this time in connection with the type of the nucleus. A table with the RUL depending on the nuclear type, for E2 and M2 transitions, respectively, is given. The number of M2 transitions is quite small. In this case, one might set the recommended upper limits with some precaution. (authors)

Nucleon self-energy in the relativistic Brueckner theory

Energy Technology Data Exchange (ETDEWEB)

Waindzoch, T; Fuchs, C; Faessler, A [Inst. fuer Theoretische Physik, Univ. Tuebingen (Germany)

1998-06-01

The self-energy of the nucleon in nuclear matter is calculated in the relativistic Brueckner theory. We solve the Thompson equation for the two nucleon scattering in the medium using different Bonn potentials. The self-energy has a rather strong momentum dependence while the equation of state compares well with previous calculations. (orig.)

Nucleon self-energy in the relativistic Brueckner theory

International Nuclear Information System (INIS)

Waindzoch, T.; Fuchs, C.; Faessler, A.

1998-01-01

The self-energy of the nucleon in nuclear matter is calculated in the relativistic Brueckner theory. We solve the Thompson equation for the two nucleon scattering in the medium using different Bonn potentials. The self-energy has a rather strong momentum dependence while the equation of state compares well with previous calculations. (orig.)

Deconfinement of quarks and gluons in nucleus-nucleus collisions

International Nuclear Information System (INIS)

Gorenstein, M.I.

2011-01-01

The energy dependence of hadron production in relativistic nucleus-nucleus collisions reveals the anomalies. They were predicted as the signals of the deconfinement phase transition and observed by NA49 collaboration in Pb+Pb collisions at the CERN SPS. This indicates the onset of the deconfinement in central nucleus-nucleus collisions at about 30 AGeV.

Elastic and inelastic proton-nucleus scattering at 156MeV: experimental study and analysis in impulse approximation

International Nuclear Information System (INIS)

Comparat, Vincent.

1975-01-01

In this work a high spatial resolution hodoscope is described. Scattered particles are detected in the image plane of a magnetic spectrometer by a proportional chamber with 96 wires of 1mm spacing. This hodoscope has been used for elastic and inelastic scattering experiments, of 156MeV protons, on 11 targets ranging from 12 C to 209 Bi. A phenomenological optical model calculation has been carried out to analyse the experimental elastic cross sections data. The dependance of the parameters as a function of the number of mass or the incident energy has been studied. The inelastic scattering results have been interpreted within the framework of the D.W.I.A. As the final results are dependant of the nucleon model, the optical potential parameters as well as the finite range approximation, several trials have been performed. Nevertheless, the DWIA seems to give about twice the experimental values for collective excitations in light or medium nuclei. The first order optical potential derived from the impulse approximation was calculated and the results compared to the experimental elastic cross sections. Several approximations were tested as non locality, off energy shell effects and the motion of the target nucleon. The usual approximation on these quantities are justified if the momentum transfer is less than 3fm -1 . The nucleon-nucleus transition matrix is obtained by solving the Lippmann-Schwinger equation, using the moment method. The first order optical potential derived from these calculations is not realistic. The intensity of the nucleon-nucleon transition is too important, and that explained the disagreement at low momentum transfers. This study shows that the multiple scattering expansion of the Lippmann-Schwinger equation, is not a good method to obtain the exact solution. It is better to do some approximations (i.e. of shell approximation) directly on the integral equation [fr

Lepton-nucleon scattering

International Nuclear Information System (INIS)

Windmolders, R.

1989-01-01

In this paper the following topics are reviewed: 1. the structure functions measured in deep inelastic e-N, μ-N and ν-N scattering; 2. nuclear effects on the structure functions; 3. nuclear effects on the fragmentation functions; 4. the spin dependent structure functions and their interpretation in terms of nucleon constituents. (orig./HSI)

Observation of Top Quark Production in Proton-Nucleus Collisions.

Science.gov (United States)

Sirunyan, A M; Tumasyan, A; Adam, W; Ambrogi, F; Asilar, E; Bergauer, T; Brandstetter, J; Brondolin, E; Dragicevic, M; Erö, J; Escalante Del Valle, A; Flechl, M; Friedl, M; Frühwirth, R; Ghete, V M; Grossmann, J; Hrubec, J; Jeitler, M; König, A; Krammer, N; Krätschmer, I; Liko, D; Madlener, T; Mikulec, I; Pree, E; Rad, N; Rohringer, H; Schieck, J; Schöfbeck, R; Spanring, M; Spitzbart, D; Waltenberger, W; Wittmann, J; Wulz, C-E; Zarucki, M; Chekhovsky, V; Mossolov, V; Suarez Gonzalez, J; De Wolf, E A; Di Croce, D; Janssen, X; Lauwers, J; Van De Klundert, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Abu Zeid, S; Blekman, F; D'Hondt, J; De Bruyn, I; De Clercq, J; Deroover, K; Flouris, G; Lontkovskyi, D; Lowette, S; Marchesini, I; Moortgat, S; Moreels, L; Python, Q; Skovpen, K; Tavernier, S; Van Doninck, W; Van Mulders, P; Van Parijs, I; Beghin, D; Bilin, B; Brun, H; Clerbaux, B; De Lentdecker, G; Delannoy, H; Dorney, B; Fasanella, G; Favart, L; Goldouzian, R; Grebenyuk, A; Kalsi, A K; Lenzi, T; Luetic, J; Maerschalk, T; Marinov, A; Seva, T; Starling, E; Vander Velde, C; Vanlaer, P; Vannerom, D; Yonamine, R; Zenoni, F; Cornelis, T; Dobur, D; Fagot, A; Gul, M; Khvastunov, I; Poyraz, D; Roskas, C; Salva, S; Tytgat, M; Verbeke, W; Zaganidis, N; Bakhshiansohi, H; Bondu, O; Brochet, S; Bruno, G; Caputo, C; Caudron, A; David, P; De Visscher, S; Delaere, C; Delcourt, M; Francois, B; Giammanco, A; Komm, M; Krintiras, G; Lemaitre, V; Magitteri, A; Mertens, A; Musich, M; Piotrzkowski, K; Quertenmont, L; Saggio, A; Vidal Marono, M; Wertz, S; Zobec, J; Aldá Júnior, W L; Alves, F L; Alves, G A; Brito, L; Correa Martins Junior, M; Hensel, C; Moraes, A; Pol, M E; Rebello Teles, P; Belchior Batista Das Chagas, E; Carvalho, W; Chinellato, J; Coelho, E; Da Costa, E M; Da Silveira, G G; De Jesus Damiao, D; Fonseca De Souza, S; Huertas Guativa, L M; Malbouisson, H; Melo De Almeida, M; Mora Herrera, C; Mundim, L; Nogima, H; Sanchez Rosas, L J; Santoro, A; Sznajder, A; Thiel, M; Tonelli Manganote, E J; Torres Da Silva De Araujo, F; Vilela Pereira, A; Ahuja, S; Bernardes, C A; Tomei, T R Fernandez Perez; Gregores, E M; Mercadante, P G; Novaes, S F; Padula, Sandra S; Romero Abad, D; Ruiz Vargas, J C; Aleksandrov, A; Hadjiiska, R; Iaydjiev, P; Misheva, M; Rodozov, M; Shopova, M; Sultanov, G; Dimitrov, A; Litov, L; Pavlov, B; Petkov, P; Fang, W; Gao, X; Yuan, L; Ahmad, M; Bian, J G; Chen, G M; Chen, H S; Chen, M; Chen, Y; Jiang, C H; Leggat, D; Liao, H; Liu, Z; Romeo, F; Shaheen, S M; Spiezia, A; Tao, J; Wang, C; Wang, Z; Yazgan, E; Zhang, H; Zhang, S; Zhao, J; Ban, Y; Chen, G; Li, J; Li, Q; Liu, S; Mao, Y; Qian, S J; Wang, D; Xu, Z; Zhang, F; Wang, Y; Avila, C; Cabrera, A; Chaparro Sierra, L F; Florez, C; González Hernández, C F; Ruiz Alvarez, J D; Segura Delgado, M A; Courbon, B; Godinovic, N; Lelas, D; Puljak, I; Ribeiro Cipriano, P M; Sculac, T; Antunovic, Z; Kovac, M; Brigljevic, V; Ferencek, D; Kadija, K; Mesic, B; Starodumov, A; Susa, T; Ather, M W; Attikis, A; Mavromanolakis, G; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Rykaczewski, H; Finger, M; Finger, M; Carrera Jarrin, E; Assran, Y; Elgammal, S; Mahrous, A; Dewanjee, R K; Kadastik, M; Perrini, L; Raidal, M; Tiko, A; Veelken, C; Eerola, P; Kirschenmann, H; Pekkanen, J; Voutilainen, M; Havukainen, J; Heikkilä, J K; Järvinen, T; Karimäki, V; Kinnunen, R; Lampén, T; Lassila-Perini, K; Laurila, S; Lehti, S; Lindén, T; Luukka, P; Siikonen, H; Tuominen, E; Tuominiemi, J; Tuuva, T; Besancon, M; Couderc, F; Dejardin, M; Denegri, D; Faure, J L; Ferri, F; Ganjour, S; Ghosh, S; Gras, P; Hamel de Monchenault, G; Jarry, P; Kucher, I; Leloup, C; Locci, E; Machet, M; Malcles, J; Negro, G; Rander, J; Rosowsky, A; Sahin, M Ö; Titov, M; Abdulsalam, A; Amendola, C; Antropov, I; Baffioni, S; Beaudette, F; Busson, P; Cadamuro, L; Charlot, C; Granier de Cassagnac, R; Jo, M; Lisniak, S; Lobanov, A; Martin Blanco, J; Nguyen, M; Ochando, C; Ortona, G; Paganini, P; Pigard, P; Salerno, R; Sauvan, J B; Sirois, Y; Stahl Leiton, A G; Strebler, T; Yilmaz, Y; Zabi, A; Zghiche, A; Agram, J-L; Andrea, J; Bloch, D; Brom, J-M; Buttignol, M; Chabert, E C; Chanon, N; Collard, C; Conte, E; Coubez, X; Fontaine, J-C; Gelé, D; Goerlach, U; Jansová, M; Le Bihan, A-C; Tonon, N; Van Hove, P; Gadrat, S; Beauceron, S; Bernet, C; Boudoul, G; Chierici, R; Contardo, D; Depasse, P; El Mamouni, H; Fay, J; Finco, L; Gascon, S; Gouzevitch, M; Grenier, G; Ille, B; Lagarde, F; Laktineh, I B; Lethuillier, M; Mirabito, L; Pequegnot, A L; Perries, S; Popov, A; Sordini, V; Vander Donckt, M; Viret, S; Toriashvili, T; Bagaturia, I; Autermann, C; Feld, L; Kiesel, M K; Klein, K; Lipinski, M; Preuten, M; Schomakers, C; Schulz, J; Teroerde, M; Zhukov, V; Albert, A; Dietz-Laursonn, E; Duchardt, D; Endres, M; Erdmann, M; Erdweg, S; Esch, T; Fischer, R; Güth, A; Hamer, M; Hebbeker, T; Heidemann, C; Hoepfner, K; Knutzen, S; Merschmeyer, M; Meyer, A; Millet, P; Mukherjee, S; Pook, T; Radziej, M; Reithler, H; Rieger, M; Scheuch, F; Teyssier, D; Thüer, S; Flügge, G; Kargoll, B; Kress, T; Künsken, A; Müller, T; Nehrkorn, A; Nowack, A; Pistone, C; Pooth, O; Stahl, A; Aldaya Martin, M; Arndt, T; Asawatangtrakuldee, C; Beernaert, K; Behnke, O; Behrens, U; Bermúdez Martínez, A; Bin Anuar, A A; Borras, K; Botta, V; Campbell, A; Connor, P; Contreras-Campana, C; Costanza, F; Diez Pardos, C; Eckerlin, G; Eckstein, D; Eichhorn, T; Eren, E; Gallo, E; Garay Garcia, J; Geiser, A; Grados Luyando, J M; Grohsjean, A; Gunnellini, P; Guthoff, M; Harb, A; Hauk, J; Hempel, M; Jung, H; Kasemann, M; Keaveney, J; Kleinwort, C; Korol, I; Krücker, D; Lange, W; Lelek, A; Lenz, T; Leonard, J; Lipka, K; Lohmann, W; Mankel, R; Melzer-Pellmann, I-A; Meyer, A B; Mittag, G; Mnich, J; Mussgiller, A; Ntomari, E; Pitzl, D; Raspereza, A; Savitskyi, M; Saxena, P; Shevchenko, R; Stefaniuk, N; Van Onsem, G P; Walsh, R; Wen, Y; Wichmann, K; Wissing, C; Zenaiev, O; Aggleton, R; Bein, S; Blobel, V; Centis Vignali, M; Dreyer, T; Garutti, E; Gonzalez, D; Haller, J; Hinzmann, A; Hoffmann, M; Karavdina, A; Klanner, R; Kogler, R; Kovalchuk, N; Kurz, S; Lapsien, T; Marconi, D; Meyer, M; Niedziela, M; Nowatschin, D; Pantaleo, F; Peiffer, T; Perieanu, A; Scharf, C; Schleper, P; Schmidt, A; Schumann, S; Schwandt, J; Sonneveld, J; Stadie, H; Steinbrück, G; Stober, F M; Stöver, M; Tholen, H; Troendle, D; Usai, E; Vanhoefer, A; Vormwald, B; Akbiyik, M; Barth, C; Baselga, M; Baur, S; Butz, E; Caspart, R; Chwalek, T; Colombo, F; De Boer, W; Dierlamm, A; Faltermann, N; Freund, B; Friese, R; Giffels, M; Harrendorf, M A; Hartmann, F; Heindl, S M; Husemann, U; Kassel, F; Kudella, S; Mildner, H; Mozer, M U; Müller, Th; Plagge, M; Quast, G; Rabbertz, K; Schröder, M; Shvetsov, I; Sieber, G; Simonis, H J; Ulrich, R; Wayand, S; Weber, M; Weiler, T; Williamson, S; Wöhrmann, C; Wolf, R; Anagnostou, G; Daskalakis, G; Geralis, T; Kyriakis, A; Loukas, D; Topsis-Giotis, I; Karathanasis, G; Kesisoglou, S; Panagiotou, A; Saoulidou, N; Kousouris, K; Evangelou, I; Foudas, C; Gianneios, P; Katsoulis, P; Kokkas, P; Mallios, S; Manthos, N; Papadopoulos, I; Paradas, E; Strologas, J; Triantis, F A; Tsitsonis, D; Csanad, M; Filipovic, N; Pasztor, G; Surányi, O; Veres, G I; Bencze, G; Hajdu, C; Horvath, D; Hunyadi, Á; Sikler, F; Veszpremi, V; Beni, N; Czellar, S; Karancsi, J; Makovec, A; Molnar, J; Szillasi, Z; Bartók, M; Raics, P; Trocsanyi, Z L; Ujvari, B; Choudhury, S; Komaragiri, J R; Bahinipati, S; Bhowmik, S; Mal, P; Mandal, K; Nayak, A; Sahoo, D K; Sahoo, N; Swain, S K; Bansal, S; Beri, S B; Bhatnagar, V; Chawla, R; Dhingra, N; Kaur, A; Kaur, M; Kaur, S; Kumar, R; Kumari, P; Mehta, A; Singh, J B; Walia, G; Kumar, Ashok; Shah, Aashaq; Bhardwaj, A; Chauhan, S; Choudhary, B C; Garg, R B; Keshri, S; Kumar, A; Malhotra, S; Naimuddin, M; Ranjan, K; Sharma, R; Bhardwaj, R; Bhattacharya, R; Bhattacharya, S; Bhawandeep, U; Dey, S; Dutt, S; Dutta, S; Ghosh, S; Majumdar, N; Modak, A; Mondal, K; Mukhopadhyay, S; Nandan, S; Purohit, A; Roy, A; Roy Chowdhury, S; Sarkar, S; Sharan, M; Thakur, S; Behera, P K; Chudasama, R; Dutta, D; Jha, V; Kumar, V; Mohanty, A K; Netrakanti, P K; Pant, L M; Shukla, P; Topkar, A; Aziz, T; Dugad, S; Mahakud, B; Mitra, S; Mohanty, G B; Sur, N; Sutar, B; Banerjee, S; Bhattacharya, S; Chatterjee, S; Das, P; Guchait, M; Jain, Sa; Kumar, S; Maity, M; Majumder, G; Mazumdar, K; Sarkar, T; Wickramage, N; Chauhan, S; Dube, S; Hegde, V; Kapoor, A; Kothekar, K; Pandey, S; Rane, A; Sharma, S; Chenarani, S; Eskandari Tadavani, E; Etesami, S M; Khakzad, M; Mohammadi Najafabadi, M; Naseri, M; Paktinat Mehdiabadi, S; Rezaei Hosseinabadi, F; Safarzadeh, B; Zeinali, M; Felcini, M; Grunewald, M; Abbrescia, M; Calabria, C; Colaleo, A; Creanza, D; Cristella, L; De Filippis, N; De Palma, M; Errico, F; Fiore, L; Iaselli, G; Lezki, S; Maggi, G; Maggi, M; Miniello, G; My, S; Nuzzo, S; Pompili, A; Pugliese, G; Radogna, R; Ranieri, A; Selvaggi, G; Sharma, A; Silvestris, L; Venditti, R; Verwilligen, P; Abbiendi, G; Battilana, C; Bonacorsi, D; Borgonovi, L; Braibant-Giacomelli, S; Campanini, R; Capiluppi, P; Castro, A; Cavallo, F R; Chhibra, S S; Codispoti, G; Cuffiani, M; Dallavalle, G M; Fabbri, F; Fanfani, A; Fasanella, D; Giacomelli, P; Grandi, C; Guiducci, L; Marcellini, S; Masetti, G; Montanari, A; Navarria, F L; Perrotta, A; Rossi, A M; Rovelli, T; Siroli, G P; Tosi, N; Albergo, S; Costa, S; Di Mattia, A; Giordano, F; Potenza, R; Tricomi, A; Tuve, C; Barbagli, G; Chatterjee, K; Ciulli, V; Civinini, C; D'Alessandro, R; Focardi, E; Lenzi, P; Meschini, M; Paoletti, S; Russo, L; Sguazzoni, G; Strom, D; Viliani, L; Benussi, L; Bianco, S; Fabbri, F; Piccolo, D; Primavera, F; Calvelli, V; Ferro, F; Ravera, F; Robutti, E; Tosi, S; Benaglia, A; Beschi, A; Brianza, L; Brivio, F; Ciriolo, V; Dinardo, M E; Fiorendi, S; Gennai, S; Ghezzi, A; Govoni, P; Malberti, M; Malvezzi, S; Manzoni, R A; Menasce, D; Moroni, L; Paganoni, M; Pauwels, K; Pedrini, D; Pigazzini, S; Ragazzi, S; Tabarelli de Fatis, T; Buontempo, S; Cavallo, N; Di Guida, S; Fabozzi, F; Fienga, F; Iorio, A O M; Khan, W A; Lista, L; Meola, S; Paolucci, P; Sciacca, C; Thyssen, F; Azzi, P; Bacchetta, N; Benato, L; Bisello, D; Boletti, A; Carlin, R; Carvalho Antunes De Oliveira, A; Checchia, P; De Castro Manzano, P; Dorigo, T; Dosselli, U; Gasparini, F; Gasparini, U; Gozzelino, A; Lacaprara, S; Margoni, M; Meneguzzo, A T; Pozzobon, N; Ronchese, P; Rossin, R; Simonetto, F; Torassa, E; Zanetti, M; Zotto, P; Zumerle, G; Braghieri, A; Magnani, A; Montagna, P; Ratti, S P; Re, V; Ressegotti, M; Riccardi, C; Salvini, P; Vai, I; Vitulo, P; Alunni Solestizi, L; Biasini, M; Bilei, G M; Cecchi, C; Ciangottini, D; Fanò, L; Leonardi, R; Manoni, E; Mantovani, G; Mariani, V; Menichelli, M; Rossi, A; Santocchia, A; Spiga, D; Androsov, K; Azzurri, P; Bagliesi, G; Boccali, T; Borrello, L; Castaldi, R; Ciocci, M A; Dell'Orso, R; Fedi, G; Giannini, L; Giassi, A; Grippo, M T; Ligabue, F; Lomtadze, T; Manca, E; Mandorli, G; Messineo, A; Palla, F; Rizzi, A; Savoy-Navarro, A; Spagnolo, P; Tenchini, R; Tonelli, G; Venturi, A; Verdini, P G; Barone, L; Cavallari, F; Cipriani, M; Daci, N; Del Re, D; Di Marco, E; Diemoz, M; Gelli, S; Longo, E; Margaroli, F; Marzocchi, B; Meridiani, P; Organtini, G; Paramatti, R; Preiato, F; Rahatlou, S; Rovelli, C; Santanastasio, F; Amapane, N; Arcidiacono, R; Argiro, S; Arneodo, M; Bartosik, N; Bellan, R; Biino, C; Cartiglia, N; Cenna, F; Costa, M; Covarelli, R; Degano, A; Demaria, N; Kiani, B; Mariotti, C; Maselli, S; Migliore, E; Monaco, V; Monteil, E; Monteno, M; Obertino, M M; Pacher, L; Pastrone, N; Pelliccioni, M; Pinna Angioni, G L; Romero, A; Ruspa, M; Sacchi, R; Shchelina, K; Sola, V; Solano, A; Staiano, A; Traczyk, P; Belforte, S; Casarsa, M; Cossutti, F; Della Ricca, G; Zanetti, A; Kim, D H; Kim, G N; Kim, M S; Lee, J; Lee, S; Lee, S W; Moon, C S; Oh, Y D; Sekmen, S; Son, D C; Yang, Y C; Lee, A; Kim, H; Moon, D H; Oh, G; Brochero Cifuentes, J A; Goh, J; Kim, T J; Cho, S; Choi, S; Go, Y; Gyun, D; Ha, S; Hong, B; Jo, Y; Kim, Y; Lee, K; Lee, K S; Lee, S; Lim, J; Park, S K; Roh, Y; Almond, J; Kim, J; Kim, J S; Lee, H; Lee, K; Nam, K; Oh, S B; Radburn-Smith, B C; Seo, S H; Yang, U K; Yoo, H D; Yu, G B; Kim, H; Kim, J H; Lee, J S H; Park, I C; Choi, Y; Hwang, C; Lee, J; Yu, I; Dudenas, V; Juodagalvis, A; Vaitkus, J; Ahmed, I; Ibrahim, Z A; Md Ali, M A B; Mohamad Idris, F; Wan Abdullah, W A T; Yusli, M N; Zolkapli, Z; Reyes-Almanza, R; Ramirez-Sanchez, G; Duran-Osuna, M C; Castilla-Valdez, H; De La Cruz-Burelo, E; Heredia-De La Cruz, I; Rabadan-Trejo, R I; Lopez-Fernandez, R; Mejia Guisao, J; Sanchez-Hernandez, A; Carrillo Moreno, S; Oropeza Barrera, C; Vazquez Valencia, F; Eysermans, J; Pedraza, I; Salazar Ibarguen, H A; Uribe Estrada, C; Morelos Pineda, A; Krofcheck, D; Butler, P H; Ahmad, A; Ahmad, M; Hassan, Q; Hoorani, H R; Saddique, A; Shah, M A; Shoaib, M; Waqas, M; Bialkowska, H; Bluj, M; Boimska, B; Frueboes, T; Górski, M; Kazana, M; Nawrocki, K; Szleper, M; Zalewski, P; Bunkowski, K; Byszuk, A; Doroba, K; Kalinowski, A; Konecki, M; Krolikowski, J; Misiura, M; Olszewski, M; Pyskir, A; Walczak, M; Bargassa, P; Beirão Da Cruz E Silva, C; Di Francesco, A; Faccioli, P; Galinhas, B; Gallinaro, M; Hollar, J; Leonardo, N; Lloret Iglesias, L; Nemallapudi, M V; Seixas, J; Strong, G; Toldaiev, O; Vadruccio, D; Varela, J; Afanasiev, S; Bunin, P; Gavrilenko, M; Golutvin, I; Gorbunov, I; Kamenev, A; Karjavin, V; Lanev, A; Malakhov, A; Matveev, V; Palichik, V; Perelygin, V; Shmatov, S; Shulha, S; Skatchkov, N; Smirnov, V; Voytishin, N; Zarubin, A; Ivanov, Y; Kim, V; Kuznetsova, E; Levchenko, P; Murzin, V; Oreshkin, V; Smirnov, I; Sosnov, D; Sulimov, V; Uvarov, L; Vavilov, S; Vorobyev, A; Andreev, Yu; Dermenev, A; Gninenko, S; Golubev, N; Karneyeu, A; Kirsanov, M; Krasnikov, N; Pashenkov, A; Tlisov, D; Toropin, A; Epshteyn, V; Gavrilov, V; Lychkovskaya, N; Popov, V; Pozdnyakov, I; Safronov, G; Spiridonov, A; Stepennov, A; Toms, M; Vlasov, E; Zhokin, A; Aushev, T; Bylinkin, A; Chistov, R; Danilov, M; Parygin, P; Philippov, D; Polikarpov, S; Tarkovskii, E; Andreev, V; Azarkin, M; Dremin, I; Kirakosyan, M; Terkulov, A; Baskakov, A; Belyaev, A; Boos, E; Dudko, L; Ershov, A; Gribushin, A; Kodolova, O; Korotkikh, V; Lokhtin, I; Miagkov, I; Obraztsov, S; Petrushanko, S; Savrin, V; Snigirev, A; Vardanyan, I; Blinov, V; Skovpen, Y; Shtol, D; Azhgirey, I; Bayshev, I; Bitioukov, S; Elumakhov, D; Godizov, A; Kachanov, V; Kalinin, A; Konstantinov, D; Mandrik, P; Petrov, V; Ryutin, R; Sobol, A; Troshin, S; Tyurin, N; Uzunian, A; Volkov, A; Adzic, P; Cirkovic, P; Devetak, D; Dordevic, M; Milosevic, J; Rekovic, V; Alcaraz Maestre, J; Bachiller, I; Barrio Luna, M; Cerrada, M; Colino, N; De La Cruz, B; Delgado Peris, A; Fernandez Bedoya, C; Fernández Ramos, J P; Flix, J; Fouz, M C; Gonzalez Lopez, O; Goy Lopez, S; Hernandez, J M; Josa, M I; Moran, D; Pérez-Calero Yzquierdo, A; Puerta Pelayo, J; Quintario Olmeda, A; Redondo, I; Romero, L; Soares, M S; Álvarez Fernández, A; Albajar, C; de Trocóniz, J F; Missiroli, M; Cuevas, J; Erice, C; Fernandez Menendez, J; Gonzalez Caballero, I; González Fernández, J R; Palencia Cortezon, E; Sanchez Cruz, S; Vischia, P; Vizan Garcia, J M; Cabrillo, I J; Calderon, A; Chazin Quero, B; Curras, E; Duarte Campderros, J; Fernandez, M; Garcia-Ferrero, J; Gomez, G; Lopez Virto, A; Marco, J; Martinez Rivero, C; Martinez Ruiz Del Arbol, P; Matorras, F; Piedra Gomez, J; Rodrigo, T; Ruiz-Jimeno, A; Scodellaro, L; Trevisani, N; Vila, I; Vilar Cortabitarte, R; Abbaneo, D; Akgun, B; Auffray, E; Baillon, P; Ball, A H; Barney, D; Bendavid, J; Bianco, M; Bloch, P; Bocci, A; Botta, C; Camporesi, T; Castello, R; Cepeda, M; Cerminara, G; Chapon, E; Chen, Y; d'Enterria, D; Dabrowski, A; Daponte, V; David, A; De Gruttola, M; De Roeck, A; Deelen, N; Dobson, M; du Pree, T; Dünser, M; Dupont, N; Elliott-Peisert, A; Everaerts, P; Fallavollita, F; Franzoni, G; Fulcher, J; Funk, W; Gigi, D; Gilbert, A; Gill, K; Glege, F; Gulhan, D; Harris, P; Hegeman, J; Innocente, V; Jafari, A; Janot, P; Karacheban, O; Kieseler, J; Knünz, V; Kornmayer, A; Kortelainen, M J; Krammer, M; Lange, C; Lecoq, P; Lourenço, C; Lucchini, M T; Malgeri, L; Mannelli, M; Martelli, A; Meijers, F; Merlin, J A; Mersi, S; Meschi, E; Milenovic, P; Moortgat, F; Mulders, M; Neugebauer, H; Ngadiuba, J; Orfanelli, S; Orsini, L; Pape, L; Perez, E; Peruzzi, M; Petrilli, A; Petrucciani, G; Pfeiffer, A; Pierini, M; Rabady, D; Racz, A; Reis, T; Rolandi, G; Rovere, M; Sakulin, H; Schäfer, C; Schwick, C; Seidel, M; Selvaggi, M; Sharma, A; Silva, P; Sphicas, P; Stakia, A; Steggemann, J; Stoye, M; Tosi, M; Treille, D; Triossi, A; Tsirou, A; Veckalns, V; Verweij, M; Zeuner, W D; Bertl, W; Caminada, L; Deiters, K; Erdmann, W; Horisberger, R; Ingram, Q; Kaestli, H C; Kotlinski, D; Langenegger, U; Rohe, T; Wiederkehr, S A; Backhaus, M; Bäni, L; Berger, P; Bianchini, L; Casal, B; Dissertori, G; Dittmar, M; Donegà, M; Dorfer, C; Grab, C; Heidegger, C; Hits, D; Hoss, J; Kasieczka, G; Klijnsma, T; Lustermann, W; Mangano, B; Marionneau, M; Meinhard, M T; Meister, D; Micheli, F; Musella, P; Nessi-Tedaldi, F; Pandolfi, F; Pata, J; Pauss, F; Perrin, G; Perrozzi, L; Quittnat, M; Reichmann, M; Sanz Becerra, D A; Schönenberger, M; Shchutska, L; Tavolaro, V R; Theofilatos, K; Vesterbacka Olsson, M L; Wallny, R; Zhu, D H; Aarrestad, T K; Amsler, C; Canelli, M F; De Cosa, A; Del Burgo, R; Donato, S; Galloni, C; Hreus, T; Kilminster, B; Pinna, D; Rauco, G; Robmann, P; Salerno, D; Schweiger, K; Seitz, C; Takahashi, Y; Zucchetta, A; Candelise, V; Chang, Y H; Cheng, K Y; Doan, T H; Jain, Sh; Khurana, R; Kuo, C M; Lin, W; Pozdnyakov, A; Yu, S S; Kumar, Arun; Chang, P; Chao, Y; Chen, K F; Chen, P H; Fiori, F; Hou, W-S; Hsiung, Y; Liu, Y F; Lu, R-S; Paganis, E; Psallidas, A; Steen, A; Tsai, J F; Asavapibhop, B; Kovitanggoon, K; Singh, G; Srimanobhas, N; Bat, A; Boran, F; Cerci, S; Damarseckin, S; Demiroglu, Z S; Dozen, C; Dumanoglu, I; Girgis, S; Gokbulut, G; Guler, Y; Hos, I; Kangal, E E; Kara, O; Kayis Topaksu, A; Kiminsu, U; Oglakci, M; Onengut, G; Ozdemir, K; Sunar Cerci, D; Tali, B; Tok, U G; Turkcapar, S; Zorbakir, I S; Zorbilmez, C; Karapinar, G; Ocalan, K; Yalvac, M; Zeyrek, M; Gülmez, E; Kaya, M; Kaya, O; Tekten, S; Yetkin, E A; Agaras, M N; Atay, S; Cakir, A; Cankocak, K; Köseoglu, I; Grynyov, B; Levchuk, L; Ball, F; Beck, L; Brooke, J J; Burns, D; Clement, E; Cussans, D; Davignon, O; Flacher, H; Goldstein, J; Heath, G P; Heath, H F; Kreczko, L; Newbold, D M; Paramesvaran, S; Sakuma, T; Seif El Nasr-Storey, S; Smith, D; Smith, V J; Belyaev, A; Brew, C; Brown, R M; Calligaris, L; Cieri, D; Cockerill, D J A; Coughlan, J A; Harder, K; Harper, S; Linacre, J; Olaiya, E; Petyt, D; Shepherd-Themistocleous, C H; Thea, A; Tomalin, I R; Williams, T; Auzinger, G; Bainbridge, R; Borg, J; Breeze, S; Buchmuller, O; Bundock, A; Casasso, S; Citron, M; Colling, D; Corpe, L; Dauncey, P; Davies, G; De Wit, A; Della Negra, M; Di Maria, R; Elwood, A; Haddad, Y; Hall, G; Iles, G; James, T; Lane, R; Laner, C; Lyons, L; Magnan, A-M; Malik, S; Mastrolorenzo, L; Matsushita, T; Nash, J; Nikitenko, A; Palladino, V; Pesaresi, M; Raymond, D M; Richards, A; Rose, A; Scott, E; Seez, C; Shtipliyski, A; Summers, S; Tapper, A; Uchida, K; Vazquez Acosta, M; Virdee, T; Wardle, N; Winterbottom, D; Wright, J; Zenz, S C; Cole, J E; Hobson, P R; Khan, A; Kyberd, P; Reid, I D; Teodorescu, L; Zahid, S; Borzou, A; Call, K; Dittmann, J; Hatakeyama, K; Liu, H; Pastika, N; Smith, C; Bartek, R; Dominguez, A; Buccilli, A; Cooper, S I; Henderson, C; Rumerio, P; West, C; Arcaro, D; Avetisyan, A; Bose, T; Gastler, D; Rankin, D; Richardson, C; Rohlf, J; Sulak, L; Zou, D; Benelli, G; Cutts, D; Garabedian, A; Hadley, M; Hakala, J; Heintz, U; Hogan, J M; Kwok, K H M; Laird, E; Landsberg, G; Lee, J; Mao, Z; Narain, M; Pazzini, J; Piperov, S; Sagir, S; Syarif, R; Yu, D; Band, R; Brainerd, C; Burns, D; Calderon De La Barca Sanchez, M; Chertok, M; Conway, J; Conway, R; Cox, P T; Erbacher, R; Flores, C; Funk, G; Ko, W; Lander, R; Mclean, C; Mulhearn, M; Pellett, D; Pilot, J; Shalhout, S; Shi, M; Smith, J; Stolp, D; Tos, K; Tripathi, M; Wang, Z; Bachtis, M; Bravo, C; Cousins, R; Dasgupta, A; Florent, A; Hauser, J; Ignatenko, M; Mccoll, N; Regnard, S; Saltzberg, D; Schnaible, C; Valuev, V; Bouvier, E; Burt, K; Clare, R; Ellison, J; Gary, J W; Ghiasi Shirazi, S M A; Hanson, G; Heilman, J; Karapostoli, G; Kennedy, E; Lacroix, F; Long, O R; Olmedo Negrete, M; Paneva, M I; Si, W; Wang, L; Wei, H; Wimpenny, S; Yates, B R; Branson, J G; Cittolin, S; Derdzinski, M; Gerosa, R; Gilbert, D; Hashemi, B; Holzner, A; Klein, D; Kole, G; Krutelyov, V; Letts, J; Masciovecchio, M; Olivito, D; Padhi, S; Pieri, M; Sani, M; Sharma, V; Tadel, M; Vartak, A; Wasserbaech, S; Wood, J; Würthwein, F; Yagil, A; Zevi Della Porta, G; Amin, N; Bhandari, R; Bradmiller-Feld, J; Campagnari, C; Dishaw, A; Dutta, V; Franco Sevilla, M; Gouskos, L; Heller, R; Incandela, J; Ovcharova, A; Qu, H; Richman, J; Stuart, D; Suarez, I; Yoo, J; Anderson, D; Bornheim, A; Lawhorn, J M; Newman, H B; Nguyen, T Q; Pena, C; Spiropulu, M; Vlimant, J R; Xie, S; Zhang, Z; Zhu, R Y; Andrews, M B; Ferguson, T; Mudholkar, T; Paulini, M; Russ, J; Sun, M; Vogel, H; Vorobiev, I; Weinberg, M; Cumalat, J P; Ford, W T; Jensen, F; Johnson, A; Krohn, M; Leontsinis, S; Mulholland, T; Stenson, K; Wagner, S R; Alexander, J; Chaves, J; Chu, J; Dittmer, S; Mcdermott, K; Mirman, N; Patterson, J R; Quach, D; Rinkevicius, A; Ryd, A; Skinnari, L; Soffi, L; Tan, S M; Tao, Z; Thom, J; Tucker, J; Wittich, P; Zientek, M; Abdullin, S; Albrow, M; Alyari, M; Apollinari, G; Apresyan, A; Apyan, A; Banerjee, S; Bauerdick, L A T; Beretvas, A; Berryhill, J; Bhat, P C; Bolla, G; Burkett, K; Butler, J N; Canepa, A; Cerati, G B; Cheung, H W K; Chlebana, F; Cremonesi, M; Duarte, J; Elvira, V D; Freeman, J; Gecse, Z; Gottschalk, E; Gray, L; Green, D; Grünendahl, S; Gutsche, O; Harris, R M; Hasegawa, S; Hirschauer, J; Hu, Z; Jayatilaka, B; Jindariani, S; Johnson, M; Joshi, U; Klima, B; Kreis, B; Lammel, S; Lincoln, D; Lipton, R; Liu, M; Liu, T; Lopes De Sá, R; Lykken, J; Maeshima, K; Magini, N; Marraffino, J M; Mason, D; McBride, P; Merkel, P; Mrenna, S; Nahn, S; O'Dell, V; Pedro, K; Prokofyev, O; Rakness, G; Ristori, L; Schneider, B; Sexton-Kennedy, E; Soha, A; Spalding, W J; Spiegel, L; Stoynev, S; Strait, J; Strobbe, N; Taylor, L; Tkaczyk, S; Tran, N V; Uplegger, L; Vaandering, E W; Vernieri, C; Verzocchi, M; Vidal, R; Wang, M; Weber, H A; Whitbeck, A; Acosta, D; Avery, P; Bortignon, P; Bourilkov, D; Brinkerhoff, A; Carnes, A; Carver, M; Curry, D; Field, R D; Furic, I K; Gleyzer, S V; Joshi, B M; Konigsberg, J; Korytov, A; Kotov, K; Ma, P; Matchev, K; Mei, H; Mitselmakher, G; Shi, K; Sperka, D; Terentyev, N; Thomas, L; Wang, J; Wang, S; Yelton, J; Joshi, Y R; Linn, S; Markowitz, P; Rodriguez, J L; Ackert, A; Adams, T; Askew, A; Hagopian, S; Hagopian, V; Johnson, K F; Kolberg, T; Martinez, G; Perry, T; Prosper, H; Saha, A; Santra, A; Sharma, V; Yohay, R; Baarmand, M M; Bhopatkar, V; Colafranceschi, S; Hohlmann, M; Noonan, D; Roy, T; Yumiceva, F; Adams, M R; Apanasevich, L; Berry, D; Betts, R R; Cavanaugh, R; Chen, X; Evdokimov, O; Gerber, C E; Hangal, D A; Hofman, D J; Jung, K; Kamin, J; Sandoval Gonzalez, I D; Tonjes, M B; Trauger, H; Varelas, N; Wang, H; Wu, Z; Zhang, J; Bilki, B; Clarida, W; Dilsiz, K; Durgut, S; Gandrajula, R P; Haytmyradov, M; Khristenko, V; Merlo, J-P; Mermerkaya, H; Mestvirishvili, A; Moeller, A; Nachtman, J; Ogul, H; Onel, Y; Ozok, F; Penzo, A; Snyder, C; Tiras, E; Wetzel, J; Yi, K; Blumenfeld, B; Cocoros, A; Eminizer, N; Fehling, D; Feng, L; Gritsan, A V; Maksimovic, P; Roskes, J; Sarica, U; Swartz, M; Xiao, M; You, C; Al-Bataineh, A; Baringer, P; Bean, A; Boren, S; Bowen, J; Castle, J; Khalil, S; Kropivnitskaya, A; Majumder, D; Mcbrayer, W; Murray, M; Rogan, C; Royon, C; Sanders, S; Schmitz, E; Tapia Takaki, J D; Wang, Q; Ivanov, A; Kaadze, K; Maravin, Y; Mohammadi, A; Saini, L K; Skhirtladze, N; Rebassoo, F; Wright, D; Baden, A; Baron, O; Belloni, A; Eno, S C; Feng, Y; Ferraioli, C; Hadley, N J; Jabeen, S; Jeng, G Y; Kellogg, R G; Kunkle, J; Mignerey, A C; Ricci-Tam, F; Shin, Y H; Skuja, A; Tonwar, S C; Abercrombie, D; Allen, B; Azzolini, V; Barbieri, R; Baty, A; Bi, R; Brandt, S; Busza, W; Cali, I A; D'Alfonso, M; Demiragli, Z; Gomez Ceballos, G; Goncharov, M; Hsu, D; Hu, M; Iiyama, Y; Innocenti, G M; Klute, M; Kovalskyi, D; Lee, Y-J; Levin, A; Luckey, P D; Maier, B; Marini, A C; Mcginn, C; Mironov, C; Narayanan, S; Niu, X; Paus, C; Roland, C; Roland, G; Salfeld-Nebgen, J; Stephans, G S F; Tatar, K; Velicanu, D; Wang, J; Wang, T W; Wyslouch, B; Benvenuti, A C; Chatterjee, R M; Evans, A; Hansen, P; Hiltbrand, J; Kalafut, S; Kubota, Y; Lesko, Z; Mans, J; Nourbakhsh, S; Ruckstuhl, N; Rusack, R; Turkewitz, J; Wadud, M A; Acosta, J G; Oliveros, S; Avdeeva, E; Bloom, K; Claes, D R; Fangmeier, C; Golf, F; Gonzalez Suarez, R; Kamalieddin, R; Kravchenko, I; Monroy, J; Siado, J E; Snow, G R; Stieger, B; Dolen, J; Godshalk, A; Harrington, C; Iashvili, I; Nguyen, D; Parker, A; Rappoccio, S; Roozbahani, B; Alverson, G; Barberis, E; Freer, C; Hortiangtham, A; Massironi, A; Morse, D M; Orimoto, T; Teixeira De Lima, R; Trocino, D; Wamorkar, T; Wang, B; Wisecarver, A; Wood, D; Bhattacharya, S; Charaf, O; Hahn, K A; Mucia, N; Odell, N; Schmitt, M H; Sung, K; Trovato, M; Velasco, M; Bucci, R; Dev, N; Hildreth, M; Hurtado Anampa, K; Jessop, C; Karmgard, D J; Kellams, N; Lannon, K; Li, W; Loukas, N; Marinelli, N; Meng, F; Mueller, C; Musienko, Y; Planer, M; Reinsvold, A; Ruchti, R; Siddireddy, P; Smith, G; Taroni, S; Wayne, M; Wightman, A; Wolf, M; Woodard, A; Alimena, J; Antonelli, L; Bylsma, B; Durkin, L S; Flowers, S; Francis, B; Hart, A; Hill, C; Ji, W; Liu, B; Luo, W; Winer, B L; Wulsin, H W; Cooperstein, S; Driga, O; Elmer, P; Hardenbrook, J; Hebda, P; Higginbotham, S; Kalogeropoulos, A; Lange, D; Luo, J; Marlow, D; Mei, K; Ojalvo, I; Olsen, J; Palmer, C; Piroué, P; Stickland, D; Tully, C; Malik, S; Norberg, S; Barker, A; Barnes, V E; Das, S; Folgueras, S; Gutay, L; Jones, M; Jung, A W; Khatiwada, A; Miller, D H; Neumeister, N; Peng, C C; Qiu, H; Schulte, J F; Sun, J; Wang, F; Xiao, R; Xie, W; Cheng, T; Parashar, N; Stupak, J; Chen, Z; Ecklund, K M; Freed, S; Geurts, F J M; Guilbaud, M; Kilpatrick, M; Li, W; Michlin, B; Padley, B P; Roberts, J; Rorie, J; Shi, W; Tu, Z; Zabel, J; Zhang, A; Bodek, A; de Barbaro, P; Demina, R; Duh, Y T; Ferbel, T; Galanti, M; Garcia-Bellido, A; Han, J; Hindrichs, O; Khukhunaishvili, A; Lo, K H; Tan, P; Verzetti, M; Ciesielski, R; Goulianos, K; Mesropian, C; Agapitos, A; Chou, J P; Gershtein, Y; Gómez Espinosa, T A; Halkiadakis, E; Heindl, M; Hughes, E; Kaplan, S; Kunnawalkam Elayavalli, R; Kyriacou, S; Lath, A; Montalvo, R; Nash, K; Osherson, M; Saka, H; Salur, S; Schnetzer, S; Sheffield, D; Somalwar, S; Stone, R; Thomas, S; Thomassen, P; Walker, M; Delannoy, A G; Heideman, J; Riley, G; Rose, K; Spanier, S; Thapa, K; Bouhali, O; Castaneda Hernandez, A; Celik, A; Dalchenko, M; De Mattia, M; Delgado, A; Dildick, S; Eusebi, R; Gilmore, J; Huang, T; Kamon, T; Mueller, R; Pakhotin, Y; Patel, R; Perloff, A; Perniè, L; Rathjens, D; Safonov, A; Tatarinov, A; Ulmer, K A; Akchurin, N; Damgov, J; De Guio, F; Dudero, P R; Faulkner, J; Gurpinar, E; Kunori, S; Lamichhane, K; Lee, S W; Libeiro, T; Mengke, T; Muthumuni, S; Peltola, T; Undleeb, S; Volobouev, I; Wang, Z; Greene, S; Gurrola, A; Janjam, R; Johns, W; Maguire, C; Melo, A; Ni, H; Padeken, K; Sheldon, P; Tuo, S; Velkovska, J; Xu, Q; Arenton, M W; Barria, P; Cox, B; Hirosky, R; Joyce, M; Ledovskoy, A; Li, H; Neu, C; Sinthuprasith, T; Wang, Y; Wolfe, E; Xia, F; Harr, R; Karchin, P E; Poudyal, N; Sturdy, J; Thapa, P; Zaleski, S; Brodski, M; Buchanan, J; Caillol, C; Dasu, S; Dodd, L; Duric, S; Gomber, B; Grothe, M; Herndon, M; Hervé, A; Hussain, U; Klabbers, P; Lanaro, A; Levine, A; Long, K; Loveless, R; Ruggles, T; Savin, A; Smith, N; Smith, W H; Taylor, D; Woods, N

2017-12-15

The first observation of top quark production in proton-nucleus collisions is reported using proton-lead data collected by the CMS experiment at the CERN LHC at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=8.16  TeV. The measurement is performed using events with exactly one isolated electron or muon candidate and at least four jets. The data sample corresponds to an integrated luminosity of 174  nb^{-1}. The significance of the tt[over ¯] signal against the background-only hypothesis is above 5 standard deviations. The measured cross section is σ_{tt[over ¯]}=45±8  nb, consistent with predictions from perturbative quantum chromodynamics.

Observation of Top Quark Production in Proton-Nucleus Collisions

Science.gov (United States)

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Escalante Del Valle, A.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Grossmann, J.; Hrubec, J.; Jeitler, M.; König, A.; Krammer, N.; Krätschmer, I.; Liko, D.; Madlener, T.; Mikulec, I.; Pree, E.; Rad, N.; Rohringer, H.; Schieck, J.; Schöfbeck, R.; Spanring, M.; Spitzbart, D.; Waltenberger, W.; Wittmann, J.; Wulz, C.-E.; Zarucki, M.; Chekhovsky, V.; Mossolov, V.; Suarez Gonzalez, J.; De Wolf, E. A.; Di Croce, D.; Janssen, X.; Lauwers, J.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; De Bruyn, I.; De Clercq, J.; Deroover, K.; Flouris, G.; Lontkovskyi, D.; Lowette, S.; Marchesini, I.; Moortgat, S.; Moreels, L.; Python, Q.; Skovpen, K.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Parijs, I.; Beghin, D.; Bilin, B.; Brun, H.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Dorney, B.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Kalsi, A. K.; Lenzi, T.; Luetic, J.; Maerschalk, T.; Marinov, A.; Seva, T.; Starling, E.; Vander Velde, C.; Vanlaer, P.; Vannerom, D.; Yonamine, R.; Zenoni, F.; Cornelis, T.; Dobur, D.; Fagot, A.; Gul, M.; Khvastunov, I.; Poyraz, D.; Roskas, C.; Salva, S.; Tytgat, M.; Verbeke, W.; Zaganidis, N.; Bakhshiansohi, H.; Bondu, O.; Brochet, S.; Bruno, G.; Caputo, C.; Caudron, A.; David, P.; De Visscher, S.; Delaere, C.; Delcourt, M.; Francois, B.; Giammanco, A.; Komm, M.; Krintiras, G.; Lemaitre, V.; Magitteri, A.; Mertens, A.; Musich, M.; Piotrzkowski, K.; Quertenmont, L.; Saggio, A.; Vidal Marono, M.; Wertz, S.; Zobec, J.; Aldá Júnior, W. L.; Alves, F. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Hensel, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Coelho, E.; Da Costa, E. M.; Da Silveira, G. G.; De Jesus Damiao, D.; Fonseca De Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Melo De Almeida, M.; Mora Herrera, C.; Mundim, L.; Nogima, H.; Sanchez Rosas, L. J.; Santoro, A.; Sznajder, A.; Thiel, M.; Tonelli Manganote, E. J.; Torres Da Silva De Araujo, F.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; Tomei, T. R. Fernandez Perez; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Misheva, M.; Rodozov, M.; Shopova, M.; Sultanov, G.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.; Fang, W.; Gao, X.; Yuan, L.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Chen, Y.; Jiang, C. H.; Leggat, D.; Liao, H.; Liu, Z.; Romeo, F.; Shaheen, S. M.; Spiezia, A.; Tao, J.; Wang, C.; Wang, Z.; Yazgan, E.; Zhang, H.; Zhang, S.; Zhao, J.; Ban, Y.; Chen, G.; Li, J.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Zhang, F.; Wang, Y.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; González Hernández, C. F.; Ruiz Alvarez, J. D.; Segura Delgado, M. A.; Courbon, B.; Godinovic, N.; Lelas, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Sculac, T.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Ferencek, D.; Kadija, K.; Mesic, B.; Starodumov, A.; Susa, T.; Ather, M. W.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Finger, M.; Finger, M.; Carrera Jarrin, E.; Assran, Y.; Elgammal, S.; Mahrous, A.; Dewanjee, R. K.; Kadastik, M.; Perrini, L.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Kirschenmann, H.; Pekkanen, J.; Voutilainen, M.; Havukainen, J.; Heikkilä, J. K.; Järvinen, T.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Laurila, S.; Lehti, S.; Lindén, T.; Luukka, P.; Siikonen, H.; Tuominen, E.; Tuominiemi, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Faure, J. L.; Ferri, F.; Ganjour, S.; Ghosh, S.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Kucher, I.; Leloup, C.; Locci, E.; Machet, M.; Malcles, J.; Negro, G.; Rander, J.; Rosowsky, A.; Sahin, M. Ö.; Titov, M.; Abdulsalam, A.; Amendola, C.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Charlot, C.; Granier de Cassagnac, R.; Jo, M.; Lisniak, S.; Lobanov, A.; Martin Blanco, J.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Stahl Leiton, A. G.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Zghiche, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Jansová, M.; Le Bihan, A.-C.; Tonon, N.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Finco, L.; Gascon, S.; Gouzevitch, M.; Grenier, G.; Ille, B.; Lagarde, F.; Laktineh, I. B.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Popov, A.; Sordini, V.; Vander Donckt, M.; Viret, S.; Toriashvili, T.; Bagaturia, I.; Autermann, C.; Feld, L.; Kiesel, M. K.; Klein, K.; Lipinski, M.; Preuten, M.; Schomakers, C.; Schulz, J.; Teroerde, M.; Zhukov, V.; Albert, A.; Dietz-Laursonn, E.; Duchardt, D.; Endres, M.; Erdmann, M.; Erdweg, S.; Esch, T.; Fischer, R.; Güth, A.; Hamer, M.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Knutzen, S.; Merschmeyer, M.; Meyer, A.; Millet, P.; Mukherjee, S.; Pook, T.; Radziej, M.; Reithler, H.; Rieger, M.; Scheuch, F.; Teyssier, D.; Thüer, S.; Flügge, G.; Kargoll, B.; Kress, T.; Künsken, A.; Müller, T.; Nehrkorn, A.; Nowack, A.; Pistone, C.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Arndt, T.; Asawatangtrakuldee, C.; Beernaert, K.; Behnke, O.; Behrens, U.; Bermúdez Martínez, A.; Bin Anuar, A. A.; Borras, K.; Botta, V.; Campbell, A.; Connor, P.; Contreras-Campana, C.; Costanza, F.; Diez Pardos, C.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Eren, E.; Gallo, E.; Garay Garcia, J.; Geiser, A.; Grados Luyando, J. M.; Grohsjean, A.; Gunnellini, P.; Guthoff, M.; Harb, A.; Hauk, J.; Hempel, M.; Jung, H.; Kasemann, M.; Keaveney, J.; Kleinwort, C.; Korol, I.; Krücker, D.; Lange, W.; Lelek, A.; Lenz, T.; Leonard, J.; Lipka, K.; Lohmann, W.; Mankel, R.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Ntomari, E.; Pitzl, D.; Raspereza, A.; Savitskyi, M.; Saxena, P.; Shevchenko, R.; Stefaniuk, N.; Van Onsem, G. P.; Walsh, R.; Wen, Y.; Wichmann, K.; Wissing, C.; Zenaiev, O.; Aggleton, R.; Bein, S.; Blobel, V.; Centis Vignali, M.; Dreyer, T.; Garutti, E.; Gonzalez, D.; Haller, J.; Hinzmann, A.; Hoffmann, M.; Karavdina, A.; Klanner, R.; Kogler, R.; Kovalchuk, N.; Kurz, S.; Lapsien, T.; Marconi, D.; Meyer, M.; Niedziela, M.; Nowatschin, D.; Pantaleo, F.; Peiffer, T.; Perieanu, A.; Scharf, C.; Schleper, P.; Schmidt, A.; Schumann, S.; Schwandt, J.; Sonneveld, J.; Stadie, H.; Steinbrück, G.; Stober, F. M.; Stöver, M.; Tholen, H.; Troendle, D.; Usai, E.; Vanhoefer, A.; Vormwald, B.; Akbiyik, M.; Barth, C.; Baselga, M.; Baur, S.; Butz, E.; Caspart, R.; Chwalek, T.; Colombo, F.; De Boer, W.; Dierlamm, A.; Faltermann, N.; Freund, B.; Friese, R.; Giffels, M.; Harrendorf, M. A.; Hartmann, F.; Heindl, S. M.; Husemann, U.; Kassel, F.; Kudella, S.; Mildner, H.; Mozer, M. U.; Müller, Th.; Plagge, M.; Quast, G.; Rabbertz, K.; Schröder, M.; Shvetsov, I.; Sieber, G.; Simonis, H. J.; Ulrich, R.; Wayand, S.; Weber, M.; Weiler, T.; Williamson, S.; Wöhrmann, C.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Kyriakis, A.; Loukas, D.; Topsis-Giotis, I.; Karathanasis, G.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Kousouris, K.; Evangelou, I.; Foudas, C.; Gianneios, P.; Katsoulis, P.; Kokkas, P.; Mallios, S.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Strologas, J.; Triantis, F. A.; Tsitsonis, D.; Csanad, M.; Filipovic, N.; Pasztor, G.; Surányi, O.; Veres, G. I.; Bencze, G.; Hajdu, C.; Horvath, D.; Hunyadi, Á.; Sikler, F.; Veszpremi, V.; Beni, N.; Czellar, S.; Karancsi, J.; Makovec, A.; Molnar, J.; Szillasi, Z.; Bartók, M.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Choudhury, S.; Komaragiri, J. R.; Bahinipati, S.; Bhowmik, S.; Mal, P.; Mandal, K.; Nayak, A.; Sahoo, D. K.; Sahoo, N.; Swain, S. K.; Bansal, S.; Beri, S. B.; Bhatnagar, V.; Chawla, R.; Dhingra, N.; Kaur, A.; Kaur, M.; Kaur, S.; Kumar, R.; Kumari, P.; Mehta, A.; Singh, J. B.; Walia, G.; Kumar, Ashok; Shah, Aashaq; Bhardwaj, A.; Chauhan, S.; Choudhary, B. C.; Garg, R. B.; Keshri, S.; Kumar, A.; Malhotra, S.; Naimuddin, M.; Ranjan, K.; Sharma, R.; Bhardwaj, R.; Bhattacharya, R.; Bhattacharya, S.; Bhawandeep, U.; Dey, S.; Dutt, S.; Dutta, S.; Ghosh, S.; Majumdar, N.; Modak, A.; Mondal, K.; Mukhopadhyay, S.; Nandan, S.; Purohit, A.; Roy, A.; Roy Chowdhury, S.; Sarkar, S.; Sharan, M.; Thakur, S.; Behera, P. K.; Chudasama, R.; Dutta, D.; Jha, V.; Kumar, V.; Mohanty, A. K.; Netrakanti, P. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Dugad, S.; Mahakud, B.; Mitra, S.; Mohanty, G. B.; Sur, N.; Sutar, B.; Banerjee, S.; Bhattacharya, S.; Chatterjee, S.; Das, P.; Guchait, M.; Jain, Sa.; Kumar, S.; Maity, M.; Majumder, G.; Mazumdar, K.; Sarkar, T.; Wickramage, N.; Chauhan, S.; Dube, S.; Hegde, V.; Kapoor, A.; Kothekar, K.; Pandey, S.; Rane, A.; Sharma, S.; Chenarani, S.; Eskandari Tadavani, E.; Etesami, S. M.; Khakzad, M.; Mohammadi Najafabadi, M.; Naseri, M.; Paktinat Mehdiabadi, S.; Rezaei Hosseinabadi, F.; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Calabria, C.; Colaleo, A.; Creanza, D.; Cristella, L.; De Filippis, N.; De Palma, M.; Errico, F.; Fiore, L.; Iaselli, G.; Lezki, S.; Maggi, G.; Maggi, M.; Miniello, G.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Ranieri, A.; Selvaggi, G.; Sharma, A.; Silvestris, L.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Battilana, C.; Bonacorsi, D.; Borgonovi, L.; Braibant-Giacomelli, S.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Chhibra, S. S.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Montanari, A.; Navarria, F. L.; Perrotta, A.; Rossi, A. M.; Rovelli, T.; Siroli, G. P.; Tosi, N.; Albergo, S.; Costa, S.; Di Mattia, A.; Giordano, F.; Potenza, R.; Tricomi, A.; Tuve, C.; Barbagli, G.; Chatterjee, K.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Lenzi, P.; Meschini, M.; Paoletti, S.; Russo, L.; Sguazzoni, G.; Strom, D.; Viliani, L.; Benussi, L.; Bianco, S.; Fabbri, F.; Piccolo, D.; Primavera, F.; Calvelli, V.; Ferro, F.; Ravera, F.; Robutti, E.; Tosi, S.; Benaglia, A.; Beschi, A.; Brianza, L.; Brivio, F.; Ciriolo, V.; Dinardo, M. E.; Fiorendi, S.; Gennai, S.; Ghezzi, A.; Govoni, P.; Malberti, M.; Malvezzi, S.; Manzoni, R. A.; Menasce, D.; Moroni, L.; Paganoni, M.; Pauwels, K.; Pedrini, D.; Pigazzini, S.; Ragazzi, S.; Tabarelli de Fatis, T.; Buontempo, S.; Cavallo, N.; Di Guida, S.; Fabozzi, F.; Fienga, F.; Iorio, A. O. M.; Khan, W. A.; Lista, L.; Meola, S.; Paolucci, P.; Sciacca, C.; Thyssen, F.; Azzi, P.; Bacchetta, N.; Benato, L.; Bisello, D.; Boletti, A.; Carlin, R.; Carvalho Antunes De Oliveira, A.; Checchia, P.; De Castro Manzano, P.; Dorigo, T.; Dosselli, U.; Gasparini, F.; Gasparini, U.; Gozzelino, A.; Lacaprara, S.; Margoni, M.; Meneguzzo, A. T.; Pozzobon, N.; Ronchese, P.; Rossin, R.; Simonetto, F.; Torassa, E.; Zanetti, M.; Zotto, P.; Zumerle, G.; Braghieri, A.; Magnani, A.; Montagna, P.; Ratti, S. P.; Re, V.; Ressegotti, M.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Alunni Solestizi, L.; Biasini, M.; Bilei, G. M.; Cecchi, C.; Ciangottini, D.; Fanò, L.; Leonardi, R.; Manoni, E.; Mantovani, G.; Mariani, V.; Menichelli, M.; Rossi, A.; Santocchia, A.; Spiga, D.; Androsov, K.; Azzurri, P.; Bagliesi, G.; Boccali, T.; Borrello, L.; Castaldi, R.; Ciocci, M. A.; Dell'Orso, R.; Fedi, G.; Giannini, L.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Manca, E.; Mandorli, G.; Messineo, A.; Palla, F.; Rizzi, A.; Savoy-Navarro, A.; Spagnolo, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Barone, L.; Cavallari, F.; Cipriani, M.; Daci, N.; Del Re, D.; Di Marco, E.; Diemoz, M.; Gelli, S.; Longo, E.; Margaroli, F.; Marzocchi, B.; Meridiani, P.; Organtini, G.; Paramatti, R.; Preiato, F.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bartosik, N.; Bellan, R.; Biino, C.; Cartiglia, N.; Cenna, F.; Costa, M.; Covarelli, R.; Degano, A.; Demaria, N.; Kiani, B.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Monteil, E.; Monteno, M.; Obertino, M. M.; Pacher, L.; Pastrone, N.; Pelliccioni, M.; Pinna Angioni, G. L.; Romero, A.; Ruspa, M.; Sacchi, R.; Shchelina, K.; Sola, V.; Solano, A.; Staiano, A.; Traczyk, P.; Belforte, S.; Casarsa, M.; Cossutti, F.; Della Ricca, G.; Zanetti, A.; Kim, D. H.; Kim, G. N.; Kim, M. S.; Lee, J.; Lee, S.; Lee, S. W.; Moon, C. S.; Oh, Y. D.; Sekmen, S.; Son, D. C.; Yang, Y. C.; Lee, A.; Kim, H.; Moon, D. H.; Oh, G.; Brochero Cifuentes, J. A.; Goh, J.; Kim, T. J.; Cho, S.; Choi, S.; Go, Y.; Gyun, D.; Ha, S.; Hong, B.; Jo, Y.; Kim, Y.; Lee, K.; Lee, K. S.; Lee, S.; Lim, J.; Park, S. K.; Roh, Y.; Almond, J.; Kim, J.; Kim, J. S.; Lee, H.; Lee, K.; Nam, K.; Oh, S. B.; Radburn-Smith, B. C.; Seo, S. h.; Yang, U. K.; Yoo, H. D.; Yu, G. B.; Kim, H.; Kim, J. H.; Lee, J. S. H.; Park, I. C.; Choi, Y.; Hwang, C.; Lee, J.; Yu, I.; Dudenas, V.; Juodagalvis, A.; Vaitkus, J.; Ahmed, I.; Ibrahim, Z. A.; Md Ali, M. A. B.; Mohamad Idris, F.; Wan Abdullah, W. A. T.; Yusli, M. N.; Zolkapli, Z.; Reyes-Almanza, R.; Ramirez-Sanchez, G.; Duran-Osuna, M. C.; Castilla-Valdez, H.; De La Cruz-Burelo, E.; Heredia-De La Cruz, I.; Rabadan-Trejo, R. I.; Lopez-Fernandez, R.; Mejia Guisao, J.; Sanchez-Hernandez, A.; Carrillo Moreno, S.; Oropeza Barrera, C.; Vazquez Valencia, F.; Eysermans, J.; Pedraza, I.; Salazar Ibarguen, H. A.; Uribe Estrada, C.; Morelos Pineda, A.; Krofcheck, D.; Butler, P. H.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Saddique, A.; Shah, M. A.; Shoaib, M.; Waqas, M.; Bialkowska, H.; Bluj, M.; Boimska, B.; Frueboes, T.; Górski, M.; Kazana, M.; Nawrocki, K.; Szleper, M.; Zalewski, P.; Bunkowski, K.; Byszuk, A.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Misiura, M.; Olszewski, M.; Pyskir, A.; Walczak, M.; Bargassa, P.; Beirão Da Cruz E Silva, C.; Di Francesco, A.; Faccioli, P.; Galinhas, B.; Gallinaro, M.; Hollar, J.; Leonardo, N.; Lloret Iglesias, L.; Nemallapudi, M. V.; Seixas, J.; Strong, G.; Toldaiev, O.; Vadruccio, D.; Varela, J.; Afanasiev, S.; Bunin, P.; Gavrilenko, M.; Golutvin, I.; Gorbunov, I.; Kamenev, A.; Karjavin, V.; Lanev, A.; Malakhov, A.; Matveev, V.; Palichik, V.; Perelygin, V.; Shmatov, S.; Shulha, S.; Skatchkov, N.; Smirnov, V.; Voytishin, N.; Zarubin, A.; Ivanov, Y.; Kim, V.; Kuznetsova, E.; Levchenko, P.; Murzin, V.; Oreshkin, V.; Smirnov, I.; Sosnov, D.; Sulimov, V.; Uvarov, L.; Vavilov, S.; Vorobyev, A.; Andreev, Yu.; Dermenev, A.; Gninenko, S.; Golubev, N.; Karneyeu, A.; Kirsanov, M.; Krasnikov, N.; Pashenkov, A.; Tlisov, D.; Toropin, A.; Epshteyn, V.; Gavrilov, V.; Lychkovskaya, N.; Popov, V.; Pozdnyakov, I.; Safronov, G.; Spiridonov, A.; Stepennov, A.; Toms, M.; Vlasov, E.; Zhokin, A.; Aushev, T.; Bylinkin, A.; Chistov, R.; Danilov, M.; Parygin, P.; Philippov, D.; Polikarpov, S.; Tarkovskii, E.; Andreev, V.; Azarkin, M.; Dremin, I.; Kirakosyan, M.; Terkulov, A.; Baskakov, A.; Belyaev, A.; Boos, E.; Dudko, L.; Ershov, A.; Gribushin, A.; Kodolova, O.; Korotkikh, V.; Lokhtin, I.; Miagkov, I.; Obraztsov, S.; Petrushanko, S.; Savrin, V.; Snigirev, A.; Vardanyan, I.; Blinov, V.; Skovpen, Y.; Shtol, D.; Azhgirey, I.; Bayshev, I.; Bitioukov, S.; Elumakhov, D.; Godizov, A.; Kachanov, V.; Kalinin, A.; Konstantinov, D.; Mandrik, P.; Petrov, V.; Ryutin, R.; Sobol, A.; Troshin, S.; Tyurin, N.; Uzunian, A.; Volkov, A.; Adzic, P.; Cirkovic, P.; Devetak, D.; Dordevic, M.; Milosevic, J.; Rekovic, V.; Alcaraz Maestre, J.; Bachiller, I.; Barrio Luna, M.; Cerrada, M.; Colino, N.; De La Cruz, B.; Delgado Peris, A.; Fernandez Bedoya, C.; Fernández Ramos, J. P.; Flix, J.; Fouz, M. C.; Gonzalez Lopez, O.; Goy Lopez, S.; Hernandez, J. M.; Josa, M. I.; Moran, D.; Pérez-Calero Yzquierdo, A.; Puerta Pelayo, J.; Quintario Olmeda, A.; Redondo, I.; Romero, L.; Soares, M. S.; Álvarez Fernández, A.; Albajar, C.; de Trocóniz, J. F.; Missiroli, M.; Cuevas, J.; Erice, C.; Fernandez Menendez, J.; Gonzalez Caballero, I.; González Fernández, J. R.; Palencia Cortezon, E.; Sanchez Cruz, S.; Vischia, P.; Vizan Garcia, J. M.; Cabrillo, I. J.; Calderon, A.; Chazin Quero, B.; Curras, E.; Duarte Campderros, J.; Fernandez, M.; Garcia-Ferrero, J.; Gomez, G.; Lopez Virto, A.; Marco, J.; Martinez Rivero, C.; Martinez Ruiz del Arbol, P.; Matorras, F.; Piedra Gomez, J.; Rodrigo, T.; Ruiz-Jimeno, A.; Scodellaro, L.; Trevisani, N.; Vila, I.; Vilar Cortabitarte, R.; Abbaneo, D.; Akgun, B.; Auffray, E.; Baillon, P.; Ball, A. H.; Barney, D.; Bendavid, J.; Bianco, M.; Bloch, P.; Bocci, A.; Botta, C.; Camporesi, T.; Castello, R.; Cepeda, M.; Cerminara, G.; Chapon, E.; Chen, Y.; d'Enterria, D.; Dabrowski, A.; Daponte, V.; David, A.; De Gruttola, M.; De Roeck, A.; Deelen, N.; Dobson, M.; du Pree, T.; Dünser, M.; Dupont, N.; Elliott-Peisert, A.; Everaerts, P.; Fallavollita, F.; Franzoni, G.; Fulcher, J.; Funk, W.; Gigi, D.; Gilbert, A.; Gill, K.; Glege, F.; Gulhan, D.; Harris, P.; Hegeman, J.; Innocente, V.; Jafari, A.; Janot, P.; Karacheban, O.; Kieseler, J.; Knünz, V.; Kornmayer, A.; Kortelainen, M. J.; Krammer, M.; Lange, C.; Lecoq, P.; Lourenço, C.; Lucchini, M. T.; Malgeri, L.; Mannelli, M.; Martelli, A.; Meijers, F.; Merlin, J. A.; Mersi, S.; Meschi, E.; Milenovic, P.; Moortgat, F.; Mulders, M.; Neugebauer, H.; Ngadiuba, J.; Orfanelli, S.; Orsini, L.; Pape, L.; Perez, E.; Peruzzi, M.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Pierini, M.; Rabady, D.; Racz, A.; Reis, T.; Rolandi, G.; Rovere, M.; Sakulin, H.; Schäfer, C.; Schwick, C.; Seidel, M.; Selvaggi, M.; Sharma, A.; Silva, P.; Sphicas, P.; Stakia, A.; Steggemann, J.; Stoye, M.; Tosi, M.; Treille, D.; Triossi, A.; Tsirou, A.; Veckalns, V.; Verweij, M.; Zeuner, W. D.; Bertl, W.; Caminada, L.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Rohe, T.; Wiederkehr, S. A.; Backhaus, M.; Bäni, L.; Berger, P.; Bianchini, L.; Casal, B.; Dissertori, G.; Dittmar, M.; Donegà, M.; Dorfer, C.; Grab, C.; Heidegger, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Klijnsma, T.; Lustermann, W.; Mangano, B.; Marionneau, M.; Meinhard, M. T.; Meister, D.; Micheli, F.; Musella, P.; Nessi-Tedaldi, F.; Pandolfi, F.; Pata, J.; Pauss, F.; Perrin, G.; Perrozzi, L.; Quittnat, M.; Reichmann, M.; Sanz Becerra, D. A.; Schönenberger, M.; Shchutska, L.; Tavolaro, V. R.; Theofilatos, K.; Vesterbacka Olsson, M. L.; Wallny, R.; Zhu, D. H.; Aarrestad, T. K.; Amsler, C.; Canelli, M. F.; De Cosa, A.; Del Burgo, R.; Donato, S.; Galloni, C.; Hreus, T.; Kilminster, B.; Pinna, D.; Rauco, G.; Robmann, P.; Salerno, D.; Schweiger, K.; Seitz, C.; Takahashi, Y.; Zucchetta, A.; Candelise, V.; Chang, Y. H.; Cheng, K. y.; Doan, T. H.; Jain, Sh.; Khurana, R.; Kuo, C. M.; Lin, W.; Pozdnyakov, A.; Yu, S. S.; Kumar, Arun; Chang, P.; Chao, Y.; Chen, K. F.; Chen, P. H.; Fiori, F.; Hou, W.-S.; Hsiung, Y.; Liu, Y. F.; Lu, R.-S.; Paganis, E.; Psallidas, A.; Steen, A.; Tsai, J. f.; Asavapibhop, B.; Kovitanggoon, K.; Singh, G.; Srimanobhas, N.; Bat, A.; Boran, F.; Cerci, S.; Damarseckin, S.; Demiroglu, Z. S.; Dozen, C.; Dumanoglu, I.; Girgis, S.; Gokbulut, G.; Guler, Y.; Hos, I.; Kangal, E. E.; Kara, O.; Kayis Topaksu, A.; Kiminsu, U.; Oglakci, M.; Onengut, G.; Ozdemir, K.; Sunar Cerci, D.; Tali, B.; Tok, U. G.; Turkcapar, S.; Zorbakir, I. S.; Zorbilmez, C.; Karapinar, G.; Ocalan, K.; Yalvac, M.; Zeyrek, M.; Gülmez, E.; Kaya, M.; Kaya, O.; Tekten, S.; Yetkin, E. A.; Agaras, M. N.; Atay, S.; Cakir, A.; Cankocak, K.; Köseoglu, I.; Grynyov, B.; Levchuk, L.; Ball, F.; Beck, L.; Brooke, J. J.; Burns, D.; Clement, E.; Cussans, D.; Davignon, O.; Flacher, H.; Goldstein, J.; Heath, G. P.; Heath, H. F.; Kreczko, L.; Newbold, D. M.; Paramesvaran, S.; Sakuma, T.; Seif El Nasr-storey, S.; Smith, D.; Smith, V. J.; Belyaev, A.; Brew, C.; Brown, R. M.; Calligaris, L.; Cieri, D.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Linacre, J.; Olaiya, E.; Petyt, D.; Shepherd-Themistocleous, C. H.; Thea, A.; Tomalin, I. R.; Williams, T.; Auzinger, G.; Bainbridge, R.; Borg, J.; Breeze, S.; Buchmuller, O.; Bundock, A.; Casasso, S.; Citron, M.; Colling, D.; Corpe, L.; Dauncey, P.; Davies, G.; De Wit, A.; Della Negra, M.; Di Maria, R.; Elwood, A.; Haddad, Y.; Hall, G.; Iles, G.; James, T.; Lane, R.; Laner, C.; Lyons, L.; Magnan, A.-M.; Malik, S.; Mastrolorenzo, L.; Matsushita, T.; Nash, J.; Nikitenko, A.; Palladino, V.; Pesaresi, M.; Raymond, D. M.; Richards, A.; Rose, A.; Scott, E.; Seez, C.; Shtipliyski, A.; Summers, S.; Tapper, A.; Uchida, K.; Vazquez Acosta, M.; Virdee, T.; Wardle, N.; Winterbottom, D.; Wright, J.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Reid, I. D.; Teodorescu, L.; Zahid, S.; Borzou, A.; Call, K.; Dittmann, J.; Hatakeyama, K.; Liu, H.; Pastika, N.; Smith, C.; Bartek, R.; Dominguez, A.; Buccilli, A.; Cooper, S. I.; Henderson, C.; Rumerio, P.; West, C.; Arcaro, D.; Avetisyan, A.; Bose, T.; Gastler, D.; Rankin, D.; Richardson, C.; Rohlf, J.; Sulak, L.; Zou, D.; Benelli, G.; Cutts, D.; Garabedian, A.; Hadley, M.; Hakala, J.; Heintz, U.; Hogan, J. M.; Kwok, K. H. M.; Laird, E.; Landsberg, G.; Lee, J.; Mao, Z.; Narain, M.; Pazzini, J.; Piperov, S.; Sagir, S.; Syarif, R.; Yu, D.; Band, R.; Brainerd, C.; Burns, D.; Calderon De La Barca Sanchez, M.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Flores, C.; Funk, G.; Ko, W.; Lander, R.; Mclean, C.; Mulhearn, M.; Pellett, D.; Pilot, J.; Shalhout, S.; Shi, M.; Smith, J.; Stolp, D.; Tos, K.; Tripathi, M.; Wang, Z.; Bachtis, M.; Bravo, C.; Cousins, R.; Dasgupta, A.; Florent, A.; Hauser, J.; Ignatenko, M.; Mccoll, N.; Regnard, S.; Saltzberg, D.; Schnaible, C.; Valuev, V.; Bouvier, E.; Burt, K.; Clare, R.; Ellison, J.; Gary, J. W.; Ghiasi Shirazi, S. M. A.; Hanson, G.; Heilman, J.; Karapostoli, G.; Kennedy, E.; Lacroix, F.; Long, O. R.; Olmedo Negrete, M.; Paneva, M. I.; Si, W.; Wang, L.; Wei, H.; Wimpenny, S.; Yates, B. R.; Branson, J. G.; Cittolin, S.; Derdzinski, M.; Gerosa, R.; Gilbert, D.; Hashemi, B.; Holzner, A.; Klein, D.; Kole, G.; Krutelyov, V.; Letts, J.; Masciovecchio, M.; Olivito, D.; Padhi, S.; Pieri, M.; Sani, M.; Sharma, V.; Tadel, M.; Vartak, A.; Wasserbaech, S.; Wood, J.; Würthwein, F.; Yagil, A.; Zevi Della Porta, G.; Amin, N.; Bhandari, R.; Bradmiller-Feld, J.; Campagnari, C.; Dishaw, A.; Dutta, V.; Franco Sevilla, M.; Gouskos, L.; Heller, R.; Incandela, J.; Ovcharova, A.; Qu, H.; Richman, J.; Stuart, D.; Suarez, I.; Yoo, J.; Anderson, D.; Bornheim, A.; Lawhorn, J. M.; Newman, H. B.; Nguyen, T. Q.; Pena, C.; Spiropulu, M.; Vlimant, J. R.; Xie, S.; Zhang, Z.; Zhu, R. Y.; Andrews, M. B.; Ferguson, T.; Mudholkar, T.; Paulini, M.; Russ, J.; Sun, M.; Vogel, H.; Vorobiev, I.; Weinberg, M.; Cumalat, J. P.; Ford, W. T.; Jensen, F.; Johnson, A.; Krohn, M.; Leontsinis, S.; Mulholland, T.; Stenson, K.; Wagner, S. R.; Alexander, J.; Chaves, J.; Chu, J.; Dittmer, S.; Mcdermott, K.; Mirman, N.; Patterson, J. R.; Quach, D.; Rinkevicius, A.; Ryd, A.; Skinnari, L.; Soffi, L.; Tan, S. M.; Tao, Z.; Thom, J.; Tucker, J.; Wittich, P.; Zientek, M.; Abdullin, S.; Albrow, M.; Alyari, M.; Apollinari, G.; Apresyan, A.; Apyan, A.; Banerjee, S.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Canepa, A.; Cerati, G. B.; Cheung, H. W. K.; Chlebana, F.; Cremonesi, M.; Duarte, J.; Elvira, V. D.; Freeman, J.; Gecse, Z.; Gottschalk, E.; Gray, L.; Green, D.; Grünendahl, S.; Gutsche, O.; Harris, R. M.; Hasegawa, S.; Hirschauer, J.; Hu, Z.; Jayatilaka, B.; Jindariani, S.; Johnson, M.; Joshi, U.; Klima, B.; Kreis, B.; Lammel, S.; Lincoln, D.; Lipton, R.; Liu, M.; Liu, T.; Lopes De Sá, R.; Lykken, J.; Maeshima, K.; Magini, N.; Marraffino, J. M.; Mason, D.; McBride, P.; Merkel, P.; Mrenna, S.; Nahn, S.; O'Dell, V.; Pedro, K.; Prokofyev, O.; Rakness, G.; Ristori, L.; Schneider, B.; Sexton-Kennedy, E.; Soha, A.; Spalding, W. J.; Spiegel, L.; Stoynev, S.; Strait, J.; Strobbe, N.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vernieri, C.; Verzocchi, M.; Vidal, R.; Wang, M.; Weber, H. A.; Whitbeck, A.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Brinkerhoff, A.; Carnes, A.; Carver, M.; Curry, D.; Field, R. D.; Furic, I. K.; Gleyzer, S. V.; Joshi, B. M.; Konigsberg, J.; Korytov, A.; Kotov, K.; Ma, P.; Matchev, K.; Mei, H.; Mitselmakher, G.; Shi, K.; Sperka, D.; Terentyev, N.; Thomas, L.; Wang, J.; Wang, S.; Yelton, J.; Joshi, Y. R.; Linn, S.; Markowitz, P.; Rodriguez, J. L.; Ackert, A.; Adams, T.; Askew, A.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Kolberg, T.; Martinez, G.; Perry, T.; Prosper, H.; Saha, A.; Santra, A.; Sharma, V.; Yohay, R.; Baarmand, M. M.; Bhopatkar, V.; Colafranceschi, S.; Hohlmann, M.; Noonan, D.; Roy, T.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Cavanaugh, R.; Chen, X.; Evdokimov, O.; Gerber, C. E.; Hangal, D. A.; Hofman, D. J.; Jung, K.; Kamin, J.; Sandoval Gonzalez, I. D.; Tonjes, M. B.; Trauger, H.; Varelas, N.; Wang, H.; Wu, Z.; Zhang, J.; Bilki, B.; Clarida, W.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Snyder, C.; Tiras, E.; Wetzel, J.; Yi, K.; Blumenfeld, B.; Cocoros, A.; Eminizer, N.; Fehling, D.; Feng, L.; Gritsan, A. V.; Maksimovic, P.; Roskes, J.; Sarica, U.; Swartz, M.; Xiao, M.; You, C.; Al-bataineh, A.; Baringer, P.; Bean, A.; Boren, S.; Bowen, J.; Castle, J.; Khalil, S.; Kropivnitskaya, A.; Majumder, D.; Mcbrayer, W.; Murray, M.; Rogan, C.; Royon, C.; Sanders, S.; Schmitz, E.; Tapia Takaki, J. D.; Wang, Q.; Ivanov, A.; Kaadze, K.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Skhirtladze, N.; Rebassoo, F.; Wright, D.; Baden, A.; Baron, O.; Belloni, A.; Eno, S. C.; Feng, Y.; Ferraioli, C.; Hadley, N. J.; Jabeen, S.; Jeng, G. Y.; Kellogg, R. G.; Kunkle, J.; Mignerey, A. C.; Ricci-Tam, F.; Shin, Y. H.; Skuja, A.; Tonwar, S. C.; Abercrombie, D.; Allen, B.; Azzolini, V.; Barbieri, R.; Baty, A.; Bi, R.; Brandt, S.; Busza, W.; Cali, I. A.; D'Alfonso, M.; Demiragli, Z.; Gomez Ceballos, G.; Goncharov, M.; Hsu, D.; Hu, M.; Iiyama, Y.; Innocenti, G. M.; Klute, M.; Kovalskyi, D.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Maier, B.; Marini, A. C.; Mcginn, C.; Mironov, C.; Narayanan, S.; Niu, X.; Paus, C.; Roland, C.; Roland, G.; Salfeld-Nebgen, J.; Stephans, G. S. F.; Tatar, K.; Velicanu, D.; Wang, J.; Wang, T. W.; Wyslouch, B.; Benvenuti, A. C.; Chatterjee, R. M.; Evans, A.; Hansen, P.; Hiltbrand, J.; Kalafut, S.; Kubota, Y.; Lesko, Z.; Mans, J.; Nourbakhsh, S.; Ruckstuhl, N.; Rusack, R.; Turkewitz, J.; Wadud, M. A.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Claes, D. R.; Fangmeier, C.; Golf, F.; Gonzalez Suarez, R.; Kamalieddin, R.; Kravchenko, I.; Monroy, J.; Siado, J. E.; Snow, G. R.; Stieger, B.; Dolen, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Nguyen, D.; Parker, A.; Rappoccio, S.; Roozbahani, B.; Alverson, G.; Barberis, E.; Freer, C.; Hortiangtham, A.; Massironi, A.; Morse, D. M.; Orimoto, T.; Teixeira De Lima, R.; Trocino, D.; Wamorkar, T.; Wang, B.; Wisecarver, A.; Wood, D.; Bhattacharya, S.; Charaf, O.; Hahn, K. A.; Mucia, N.; Odell, N.; Schmitt, M. H.; Sung, K.; Trovato, M.; Velasco, M.; Bucci, R.; Dev, N.; Hildreth, M.; Hurtado Anampa, K.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Li, W.; Loukas, N.; Marinelli, N.; Meng, F.; Mueller, C.; Musienko, Y.; Planer, M.; Reinsvold, A.; Ruchti, R.; Siddireddy, P.; Smith, G.; Taroni, S.; Wayne, M.; Wightman, A.; Wolf, M.; Woodard, A.; Alimena, J.; Antonelli, L.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Francis, B.; Hart, A.; Hill, C.; Ji, W.; Liu, B.; Luo, W.; Winer, B. L.; Wulsin, H. W.; Cooperstein, S.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Higginbotham, S.; Kalogeropoulos, A.; Lange, D.; Luo, J.; Marlow, D.; Mei, K.; Ojalvo, I.; Olsen, J.; Palmer, C.; Piroué, P.; Stickland, D.; Tully, C.; Malik, S.; Norberg, S.; Barker, A.; Barnes, V. E.; Das, S.; Folgueras, S.; Gutay, L.; Jones, M.; Jung, A. W.; Khatiwada, A.; Miller, D. H.; Neumeister, N.; Peng, C. C.; Qiu, H.; Schulte, J. F.; Sun, J.; Wang, F.; Xiao, R.; Xie, W.; Cheng, T.; Parashar, N.; Stupak, J.; Chen, Z.; Ecklund, K. M.; Freed, S.; Geurts, F. J. M.; Guilbaud, M.; Kilpatrick, M.; Li, W.; Michlin, B.; Padley, B. P.; Roberts, J.; Rorie, J.; Shi, W.; Tu, Z.; Zabel, J.; Zhang, A.; Bodek, A.; de Barbaro, P.; Demina, R.; Duh, Y. t.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Han, J.; Hindrichs, O.; Khukhunaishvili, A.; Lo, K. H.; Tan, P.; Verzetti, M.; Ciesielski, R.; Goulianos, K.; Mesropian, C.; Agapitos, A.; Chou, J. P.; Gershtein, Y.; Gómez Espinosa, T. A.; Halkiadakis, E.; Heindl, M.; Hughes, E.; Kaplan, S.; Kunnawalkam Elayavalli, R.; Kyriacou, S.; Lath, A.; Montalvo, R.; Nash, K.; Osherson, M.; Saka, H.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Delannoy, A. G.; Heideman, J.; Riley, G.; Rose, K.; Spanier, S.; Thapa, K.; Bouhali, O.; Castaneda Hernandez, A.; Celik, A.; Dalchenko, M.; De Mattia, M.; Delgado, A.; Dildick, S.; Eusebi, R.; Gilmore, J.; Huang, T.; Kamon, T.; Mueller, R.; Pakhotin, Y.; Patel, R.; Perloff, A.; Perniè, L.; Rathjens, D.; Safonov, A.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Damgov, J.; De Guio, F.; Dudero, P. R.; Faulkner, J.; Gurpinar, E.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Mengke, T.; Muthumuni, S.; Peltola, T.; Undleeb, S.; Volobouev, I.; Wang, Z.; Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Sheldon, P.; Tuo, S.; Velkovska, J.; Xu, Q.; Arenton, M. W.; Barria, P.; Cox, B.; Hirosky, R.; Joyce, M.; Ledovskoy, A.; Li, H.; Neu, C.; Sinthuprasith, T.; Wang, Y.; Wolfe, E.; Xia, F.; Harr, R.; Karchin, P. E.; Poudyal, N.; Sturdy, J.; Thapa, P.; Zaleski, S.; Brodski, M.; Buchanan, J.; Caillol, C.; Dasu, S.; Dodd, L.; Duric, S.; Gomber, B.; Grothe, M.; Herndon, M.; Hervé, A.; Hussain, U.; Klabbers, P.; Lanaro, A.; Levine, A.; Long, K.; Loveless, R.; Ruggles, T.; Savin, A.; Smith, N.; Smith, W. H.; Taylor, D.; Woods, N.; CMS Collaboration

2017-12-01

The first observation of top quark production in proton-nucleus collisions is reported using proton-lead data collected by the CMS experiment at the CERN LHC at a nucleon-nucleon center-of-mass energy of √{sN N }=8.16 TeV . The measurement is performed using events with exactly one isolated electron or muon candidate and at least four jets. The data sample corresponds to an integrated luminosity of 174 nb-1 . The significance of the t t ¯ signal against the background-only hypothesis is above 5 standard deviations. The measured cross section is σt t ¯=45 ±8 nb , consistent with predictions from perturbative quantum chromodynamics.

On the nucleon-nucleon potential obtained from non-linear coupling

International Nuclear Information System (INIS)

El Ghabaty, S.S.

1975-07-01

The static limit of a pseudoscalar symmetric meson theory of nuclear forces is examined. The Born-Oppenheimer potential is determined for the case of two very heavy nucleons exchanging pseudoscalar isovector pions with non-linear coupling. It is found that the non-linear terms induced by the γ 5 coupling are cancelled by the additional pion-nucleon coupling of the non-linear sigma model. The nucleon-nucleon potential thus obtained is the same as the Yukava potential except for strength at different separations between the two nucleons

Integrity of Cerebellar Fastigial Nucleus Intrinsic Neurons Is Critical for the Global Ischemic Preconditioning

Directory of Open Access Journals (Sweden)

Eugene V. Golanov

2017-09-01

Full Text Available Excitation of intrinsic neurons of cerebellar fastigial nucleus (FN renders brain tolerant to local and global ischemia. This effect reaches a maximum 72 h after the stimulation and lasts over 10 days. Comparable neuroprotection is observed following sublethal global brain ischemia, a phenomenon known as preconditioning. We hypothesized that FN may participate in the mechanisms of ischemic preconditioning as a part of the intrinsic neuroprotective mechanism. To explore potential significance of FN neurons in brain ischemic tolerance we lesioned intrinsic FN neurons with excitotoxin ibotenic acid five days before exposure to 20 min four-vessel occlusion (4-VO global ischemia while analyzing neuronal damage in Cornu Ammoni area 1 (CA1 hippocampal area one week later. In FN-lesioned animals, loss of CA1 cells was higher by 22% compared to control (phosphate buffered saline (PBS-injected animals. Moreover, lesion of FN neurons increased morbidity following global ischemia by 50%. Ablation of FN neurons also reversed salvaging effects of five-minute ischemic preconditioning on CA1 neurons and morbidity, while ablation of cerebellar dentate nucleus neurons did not change effect of ischemic preconditioning. We conclude that FN is an important part of intrinsic neuroprotective system, which participates in ischemic preconditioning and may participate in naturally occurring neuroprotection, such as “diving response”.

Nucleon quark structure and strong meson-nucleon form factors

International Nuclear Information System (INIS)

Efimov, G.V.; Ivanov, M.A.

1987-01-01

The nucleon is considered as a three-quark system in virton-quark model. The main statistic properties of proton and neutron are calculated: magnetic moments, electromagnetic radii, G A /G V ratio in weak neutron decay. Strong meson-nucleon form factors which determine nucleon-nucleon potential are obtained as a function of squared transfer momentum of mesons. The results are compared with phenomenological form factors used for description of phases of NN-scattering in the one-boson-, exchange model

Pion-nucleon vertex function with one nucleon off shell

International Nuclear Information System (INIS)

Mizutani, T.; Rochus, P.

1979-01-01

The pion-nucleon vertex function with an off-mass-shell nucleon is obtained through sideways dispersion relations with the P 11 and S 11 pion-nucleon phase shifts as only input. Contrary to the recent calculation of Nutt and Shakin, we find that the proper and improper vertex functions behave quite differently, indicating the importance of the nucleon propagator dressing. In particular the proper vertex function is found to have two poles in the unphysical region

Method of a fast selection of inelastic nucleus-nucleus collisions for the CMS experiment

International Nuclear Information System (INIS)

Krasnov, V.A.; Malakhov, A.I.; Savina, M.V.; Shmatov, S.V.; Zarubin, P.I.

1998-01-01

On the basis of the HIJING generator simulation of heavy ion collisions at ultrarelativistic energy scale, a method of a fast selection of inelastic nucleus-nucleus interactions is proposed for the CMS experiment at LHC. The basic idea is to use the time coincidence of signals with resolution better than 1 ns from the two very forward calorimeter arms covering the acceptance 3<|η|<5. The method efficiency is investigated by variation of energy thresholds in the calorimeters for different colliding ion species, namely, PbPb, NbNb, CaCa, OO, pPb, pCa, pp. It is shown that a stable efficiency of event selection (∼98%) is provided in an energy threshold range up to 100 GeV for nuclear collisions at 5 TeV/nucleon in the centre of mass system. In the pp collision case the relevant efficiency drops from 93% down to 80%

Description of nucleon scattering on 208Pb by a fully Lane-consistent dispersive spherical optical model potential

Science.gov (United States)

Sun, W. L.; Wang, J.; Soukhovitskii, E. Sh.; Capote, R.; Quesada, J. M.

2017-09-01

A fully Lane-consistent dispersive spherical optical potential is proposed to describe nucleon scattering interaction with doubly magic nucleus 208Pb up to 200 MeV. The experimental neutron total cross sections, elastically scattered nucleon angular distributions and (p,n) data had been used to search the potential parameters. Good agreement between experiments and the calculations with this potential is observed. Meanwhile, the application of the determined optical potential with the same parameters to neighbouring near magic Pb-Bi isotopes is also examined to show the predictive power of this potential.

The reactive content of the proton-nucleus impulse - approximation Dirac optical potential

International Nuclear Information System (INIS)

Carlson, B.V.; Isidro Filho, M.P.; Hussein, M.S.

1984-01-01

The total reaction cross sections for intermediate energy proton scattering on 40 Ca and 208 Pb are calculated within the Dirac-Eikonal formalism. Comparison with data indicate that the recently proposed impulse-approximation Dirac optical potential for nucleon-nucleus scattering, is not absorptive enough. (Author) [pt

Measurement of the transverse energy spectrum in proton-nucleon collisions

International Nuclear Information System (INIS)

Bettoni, D.

1988-01-01

The author describes a measurement of the transverse energy spectrum in proton-nucleon interactions carried out at the CERN SPS using the HELIOS spectrometer. The measurement is of particular interest in that it is performed in a rapidity region away from central rapidity, where experimental data is scarce. In this rapidity region very interesting physics is anticipated and the measurement of the proton-nucleon collisions is essential as a basis to understand the more complicated proton-nucleus and nucleus-nucleus interactions. Both these topics are part of the experimental program of HELIOS. The measurement was done using a deuterium target enclosed in an iron tube. The contribution to the transverse energy spectrum from the p-Fe events is discriminated against by reconstructing the primary interaction vertex using drift chamber information. The measured spectrum is corrected via Monte Carlo to deconvolute the effect of reinteractions. High spatial resolution and multi-track resolving power are achieved with the use of a cool gas, such that the electron characteristic energy is close to the thermal limit: this implies a small diffusion coefficient and a consequently good positional accuracy. Of vital importance are the low value of the drift velocity, the fast, differentiating electronics and a careful shaping of the electric field configuration to improve the isochrony of the drift collection. The author reports on the design and tests of drift chamber prototypes built along the above lines, with which a spatial accuracy of 0.06 mm and a double track resolution of 0.6 mm were measured. He also describes the final drift chamber system and its operation in HELIOS

Quark bags, P-matrix and nucleon-nucleon scattering

International Nuclear Information System (INIS)

Narodetskij, I.M.

1984-01-01

This paper is an extended version of the talk given at IX European Conference on Few Body Problems in Physics, Tbilisi, 1984. It reviews recent developments of the quark compound bag (QCB) model including explicit examples of the QCB nucleon-nucleon potentials, description of the deuteron properties, calculation of the six quark admixture in the deuteron and applications to the three-nucleon system

Nucleon quark distributions in a covariant quark-diquark model

Energy Technology Data Exchange (ETDEWEB)

Cloet, I.C. [Special Research Centre for the Subatomic Structure of Matter and Department of Physics and Mathematical Physics, University of Adelaide, SA 5005 (Australia) and Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)]. E-mail: icloet@physics.adelaide.edu.au; Bentz, W. [Department of Physics, School of Science, Tokai University, Hiratsuka-shi, Kanagawa 259-1292 (Japan)]. E-mail: bentz@keyaki.cc.u-tokai.ac.jp; Thomas, A.W. [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)]. E-mail: awthomas@jlab.org

2005-08-18

Spin-dependent and spin-independent quark light-cone momentum distributions and structure functions are calculated for the nucleon. We utilize a modified Nambu-Jona-Lasinio model in which confinement is simulated by eliminating unphysical thresholds for nucleon decay into quarks. The nucleon bound state is obtained by solving the Faddeev equation in the quark-diquark approximation, where both scalar and axial-vector diquark channels are included. We find excellent agreement between our model results and empirical data.

Sum rule measurements of the spin-dependent compton amplitude (nucleon spin structure at Q2 = 0)

International Nuclear Information System (INIS)

Babusci, D.; Giordano, G.; Baghaei, H.; Cichocki, A.; Blecher, M.; Breuer, M.; Commeaux, C.; Didelez, J.P.; Caracappa, A.; Fan, Q.

1995-01-01

Energy weighted integrals of the difference in helicity-dependent photo-production cross sections (σ 1/2 - σ 3/2 ) provide information on the nucleon's Spin-dependent Polarizability (γ), and on the spin-dependent part of the asymptotic forward Compton amplitude through the Drell-Hearn-Gerasimov (DHG) sum rule. (The latter forms the Q 2 =0 limit of recent spin-asymmetry experiments in deep-inelastic lepton-scattering.) There are no direct measurements of σ 1/2 or σ 3/2 , for either the proton or the neutron. Estimates from current π-photo-production multipole analyses, particularly for the proton-neutron difference, are in good agreement with relativistic-l-loop Chiral calculations (χPT) for γ but predict large deviations from the DHG sum rule. Either (a) both the 2-loop corrections to the Spin-Polarizability are large and the existing multipoles are wrong, or (b) modifications to the Drell-Hearn-Gerasimov sum rule are required to fully describe the isospin structure of the nucleon. The helicity-dependent photo-reaction amplitudes, for both the proton and the neutron, will be measured at LEGS from pion-threshold to 470 MeV. In these double-polarization experiments, circularly polarized photons from LEGS will be used with SPHICE, a new frozen-spin target consisting of rvec H · rvec D in the solid phase. Reaction channels will be identified in SASY, a large detector array covering about 80% of 4π. A high degree of symmetry in both target and detector will be used to minimize systematic uncertainties

Energy dependence of the thermodynamical parameters in nucleus-nucleus collisions from 1A to 200A GeV

International Nuclear Information System (INIS)

Hong, Byung Sik

1999-01-01

The energy dependence of the thermodynamical parameters in nucleus-nucleus collisions are studied from 1A to 200A GeV in the framework of the statistical thermal model. The energy and entropy densities, as well as the pressure, of hot and dense hadronic matter are calculated by using the available input parameters of the model. No discontinuity or steep rise in the thermodynamical parameters has been found. The equation of state in terms of the speed of sound is investigated as a function of the energy density, and it increases monotonically up to 200A GeV. The estimated sonic velocities above 10A GeV are very close to that of an ideal ultrarelativistic hadron gas in the presence of resonances

Proton nucleus elastic scattering at 800 MeV: the role of intermediate isobars

International Nuclear Information System (INIS)

Auger, J.P.; Maillet, J.P.; Lazard, C.; Lombard, R.J.

1984-10-01

Proton nucleus elastic scattering at 800 MeV has been calculated in the Glauber model for 16 O, 40 Ca, 48 Ca and 208 Pb. Nuclear densities are taken from Hartree-Fock-BCS calculations. For the nucleon-nucleon amplitudes, use is made of two recent phase shift analysis. The effects of intermediate isobars are included by means of a simple model. The results show that the experimental data are qualitatively understood. The polarization turns out to be quite sensitive to the intermediate isobar effects, which consequently need to be calculated more carefully

Dependence of two-proton radioactivity on nuclear pairing models

Science.gov (United States)

Oishi, Tomohiro; Kortelainen, Markus; Pastore, Alessandro

2017-10-01

Sensitivity of two-proton emitting decay to nuclear pairing correlation is discussed within a time-dependent three-body model. We focus on the 6Be nucleus assuming α +p +p configuration, and its decay process is described as a time evolution of the three-body resonance state. For a proton-proton subsystem, a schematic density-dependent contact (SDDC) pairing model is employed. From the time-dependent calculation, we observed the exponential decay rule of a two-proton emission. It is shown that the density dependence does not play a major role in determining the decay width, which can be controlled only by the asymptotic strength of the pairing interaction. This asymptotic pairing sensitivity can be understood in terms of the dynamics of the wave function driven by the three-body Hamiltonian, by monitoring the time-dependent density distribution. With this simple SDDC pairing model, there remains an impossible trinity problem: it cannot simultaneously reproduce the empirical Q value, decay width, and the nucleon-nucleon scattering length. This problem suggests that a further sophistication of the theoretical pairing model is necessary, utilizing the two-proton radioactivity data as the reference quantities.

Study of hyperon-nucleon interactions with d(e,e'K) reactions

International Nuclear Information System (INIS)

Lee, T.-S. H.

1998-01-01

The dependence of the d(e,eprimeK + ) reaction cross sections on the hyperon-nucleon interactions is investigated. It is shown that the data obtained with Longitudinal-Transverse separation or polarized photons can distinguish a class of Nijmegen models of hyperon-nucleon interactions which are χ 2 -equivalent in fitting the existing 35 data points of hyperon-nucleon reactions

Investigation of the nucleon structure and the nucleon-nucleon interaction by electron-deuteron scattering

International Nuclear Information System (INIS)

Simon, G.G.

1978-01-01

In this thesis results of measurements of the differential cross sections of the elastic and inelastic electron deuteron scattering are presented. The data were taken at several scattering angles and in the electron energy range of 150 MeV up to 320 MeV. The extracted form factors and structure functions are compared with theoretical results which are sensitive to details of nucleon structure and of the nucleon-nucleon forces. (FKS)

Development of axial asymmetry in the neutron-rich nucleus {sup 110}Mo

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H., E-mail: hiroshi@ribf.riken.jp [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yamaguchi, K.; Odahara, A. [Department of Physics, Osaka University, Machikaneyama-machi 1-1, Osaka 560-0043 Toyonaka (Japan); Sumikama, T. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Nishimura, S. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yoshinaga, K. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Li, Z. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Miyashita, Y. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Sato, K. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Prochniak, L. [Institute of Physics, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 1, 20-031 Lublin (Poland); Baba, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Berryman, J.S. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Blasi, N. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Bracco, A.; Camera, F. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, via Celoria 16, I-20133 Milano (Italy); Chiba, J. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Doornenbal, P. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Go, S.; Hashimoto, T.; Hayakawa, S. [Center for Nuclear Study, University of Tokyo, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan)

2011-10-19

The neutron-rich nucleus {sup 110}Mo has been investigated by means of {gamma}-ray spectroscopy following the {beta}-decay of {sup 110}Nb, produced using in-flight fission of a {sup 238}U beam at 345 MeV/nucleon at the RIBF facility. In addition to the ground-band members reported previously, spectroscopic information on the low-lying levels of the quasi-{gamma} band built on the second 2{sup +} state at 494 keV has been obtained for the first time. The experimental finding of the second 2{sup +} state being lower than the yrast 4{sup +} level suggests that axially-asymmetric {gamma} softness is substantially enhanced in this nucleus. The experimental results are compared with model calculations based on the general Bohr Hamiltonian method. The systematics of the low-lying levels in even-even A{approx}110 nuclei is discussed in comparison with that in the neutron-rich A{approx}190 region, by introducing the quantity E{sub S}/E(2{sub 1}{sup +}), E{sub S}=E(2{sub 2}{sup +})-E(4{sub 1}{sup +}), as a global signature of the structural evolution involving axial asymmetry.

Effects of chiral three-nucleon forces on 4He-nucleus scattering in a wide range of incident energies

Science.gov (United States)

Toyokawa, Masakazu; Yahiro, Masanobu; Matsumoto, Takuma; Kohno, Michio

2018-02-01

An important current subject is to clarify the properties of chiral three-nucleon forces (3NFs) not only in nuclear matter but also in scattering between finite-size nuclei. Particularly for elastic scattering, this study has just started and the properties are not understood for a wide range of incident energies (E_in). We investigate basic properties of chiral 3NFs in nuclear matter with positive energies by using the Brueckner-Hartree-Fock method with chiral two-nucleon forces at N3LO and 3NFs at NNLO, and analyze the effects of chiral 3NFs on 4He elastic scattering from targets ^{208}Pb, ^{58}Ni, and ^{40}Ca over a wide range of 30 ≲ E_in/A_P ≲ 200 MeV by using the g-matrix folding model, where A_P is the mass number of the projectile. In symmetric nuclear matter with positive energies, chiral 3NFs make the single-particle potential less attractive and more absorptive. The effects mainly come from the Fujita-Miyazawa 2π-exchange 3NF and become slightly larger as E_in increases. These effects persist in the optical potentials of 4He scattering. As for the differential cross sections of 4He scattering, chiral-3NF effects are large for E_in/A_P ≳ 60 MeV and improve the agreement of the theoretical results with the measured ones. Particularly for E_in/A_P ≳ 100 MeV, the folding model reproduces measured differential cross sections pretty well. Cutoff (Λ) dependence is investigated for both nuclear matter and 4He scattering by considering two cases of Λ=450 and 550 MeV. The uncertainty coming from the dependence is smaller than chiral-3NF effects even at E_in/A_P=175 MeV.

On the sensitivity of nucleon-nucleon correlations to the form of short-range potential

International Nuclear Information System (INIS)

Gmitro, M.; Kvasil, J.; Lednicky, R.; Lyuboshitz, V.L.

1986-01-01

Nucleon-nucleon correlation characteristics are calculated for several phenomenological and realistic strong potentials. The results show that a square-well potential reasonably well approximates the nucleon-nucleon interaction if one calculates the correlations between nucleons generated in a region with an r.m.s. radius larger than 1.5-2 fm. Vice versa, the correlations of nucleons emitted from a smaller generation region are sensitive to the form of the assumed nucleon-nucleon potential. (author)

Chiral symmetry and the nucleon--nucleon interaction

International Nuclear Information System (INIS)

Brown, G.E.

1977-01-01

The nucleon--nucleon interaction is understood in terms of a dynamic model, the sigma model. The anti NN → ππ helicity amplitudes are assumed to be physical data, and the dynamical model must reproduce these data, more or less. 14 references

Temperature dependent relativistic microscopic optical potential and mean free paths of nucleons

International Nuclear Information System (INIS)

Han Yinlu; Shen Qingbiao; Zhuo Yizhong

1993-01-01

The relativistic microscopic optical potential, mean free paths and Schroedinger equivalent potential of nucleons at finite temperature in nuclear matter are studied based on Walecka's model and thermo field dynamics. We let only the Hartree-Fock self-energy of nucleon represent to be the real part of the microscopic optical potential and the fourth order of meson exchange diagrams, i.e. the core polarization represent the imaginary part of microscopic optical potential in nuclear matter. The microscopic optical potential of finite nuclei is obtained with the local density approximation

Nucleon-nucleon interaction with quark exchanges and prediction to colour van der Waals potential

International Nuclear Information System (INIS)

Osman, A.

1985-11-01

The nucleon-nucleon interaction is considered by including the colour nucleon clusters. The nucleon-nucleon system is treated as a six-quark system. The obtained local potentials reduce the short-range repulsion. The resulted nucleon-nucleon potential by using a quark-quark potential well agrees with the central-force potentials. The phase shifts calculated by using these local potentials are in good agreement with those obtained from other methods. Introducing the quark-quark potential in the nucleon-nucleon interaction, leads to a colour van der Waals potential very strong compared with that predicted by experiments. (author)

Radiative capture of nucleons at astrophysical energies with single-particle states

International Nuclear Information System (INIS)

Huang, J.T.; Bertulani, C.A.; Guimaraes, V.

2010-01-01

Radiative capture of nucleons at energies of astrophysical interest is one of the most important processes for nucleosynthesis. The nucleon capture can occur either by a compound nucleus reaction or by a direct process. The compound reaction cross sections are usually very small, especially for light nuclei. The direct capture proceeds either via the formation of a single-particle resonance or a non-resonant capture process. In this work we calculate radiative capture cross sections and astrophysical S-factors for nuclei in the mass region A<20 using single-particle states. We carefully discuss the parameter fitting procedure adopted in the simplified two-body treatment of the capture process. Then we produce a detailed list of cases for which the model works well. Useful quantities, such as spectroscopic factors and asymptotic normalization coefficients, are obtained and compared to published data.

Dependence of displacement fields on the damage cluster nucleus geometry

International Nuclear Information System (INIS)

Grigor'ev, A.N.; Zabela, A.G.; Nikolajchuk, L.I.; Prokhorenko, E.M.; Khizhnyak, N.A.

1988-01-01

Displacement fields in doped crystals of cubic and hexagonal structures containing extended defects are studied. The numerical results are presented depending on the damage cluster nucleus geometry. All calculations are based on analytical representations of displacement fields in an integral form using elasticity theory equations. The investigation results are vital for radiation physics as they permit to predict and calculate both the character and geometry of distortions near damaged region cluster and determine cluster parameters on the basis of the known structure of distortions. Dependences are obtained for the following monocrystals: Mg, ZnO, CdS, W, Au. 6 refs.; 3 figs

Application of RQMD and FRITIOF models for description of nucleus-nucleus interactions at energy of 3.36 GeV/nucleon

International Nuclear Information System (INIS)

Galoyan, A.S.; Kladnitskaya, E.N.; Rogachevskij, O.V.; Uzhinskij, V.V.

2001-01-01

Experimental data on proton and π - -meson rapidity distributions in CC-interactions at 3.36 GeV/nucleon in the events with different multiplicities of produced π - -mesons are presented. The data are compared with predictions of RQMD and FRITIOF models. It is shown that the RQMD model reproduces satisfactorily the π - -meson distributions, but unsatisfactorily describes the protons characteristics. The FRITIOF model gives good results at tuning the free parameters of the model

Nucleon-antinucleon interaction

International Nuclear Information System (INIS)

Dover, C.B.

1983-01-01

The current status of our understanding of the low energy nucleon-antinucleon (N anti N) interaction is reviewed. We compare several phenomenological models which fit the available N anti N cross section data. The more realistic of these models employ an annihilation potential W(r) which is spin, isospin and energy dependent. The microscopic origins for these dependences are discussed in terms of quark rearrangement and annihilation processes. It is argued that the study of N anti N annihilation offers a powerful means of studying quark dynamics at short distances. We also discuss how one may try to isolate coherent meson exchange contributions to the medium and long range part of the N anti N potential. These pieces of the N anti N interaction are calculable via the G-parity transformation from a model for the NN potential; their effects are predicted to be seen in N anti N spin observables, to be measured at LEAR. The possible existence of quasi-stable bound states or resonances of the anti N plus one or more nucleons is discussed, with emphasis on few-body systems. 42 references

Overview of polarization in intermediate energy nucleon-nucleus inelastic scattering

International Nuclear Information System (INIS)

Carey, T.

1985-01-01

The general role that polarization transfer (PT) can play in the ''dissection'' of medium-energy N-nucleus inelastic reactions is reviewed, specifically concentrating on the importance of complete sets of PT observables for the study of nuclear structure. The discussion is largely in the context of plane-wave impulse approximations, with the effects of distortions considered through comparisons between simple plane-wave predictions and DWIA computations. 31 refs., 11 figs

Internal Spin Structure of the Nucleon in Polarized Deep Inelastic Muon-Nucleon Scattering

International Nuclear Information System (INIS)

Wislicki, W.

1998-01-01

We present the study of the internal spin structure of the nucleon in spin-dependent deep inelastic scattering of muons on nucleons. The data were taken by the NA47 experiment of the Spin Muon Collaboration (SMC) on the high energy muon beam at CERN. The experiment used the polarized proton and deuteron targets. The structure function g 1 p (x) and g 1 d (x) were determined from the asymmetries of the spin-dependent event rates in the range of 0.003 2 >=10 GeV 2 . Using the first moments of these structure functions an agreement with the Bjorken sum rule prediction was found within one standard deviation. The first moments of g 1 (x), for both proton and deuteron, are smaller than the Ellis-Jaffe sum rule prediction. This disagreement can be interpreted in terms of negative polarization of the strange sea in the nucleon. The singlet part of the axial current matrix element can be interpreted as an overall spin carried by quarks in the nucleon. Its value is significantly smaller than nucleon spin. Semi-inclusive asymmetries of yields of positive and negative hadrons produced on both targets were also measured and analysed in term of quark-parton model, together with inclusive asymmetries. From this analysis the quark spin distributions were determined, separately for valence u and d quarks and for non-strange sea quarks. Valence u quarks are positively polarized and their polarization increases with x. Valence d quarks are negatively polarized and their polarization does not exhibit any x-dependence. The non-strange sea is unpolarized in the whole measured range of x. The first moments of the valance quark spin distributions were found consistent with the values obtained from weak decay constants F and D and their second moments are consistent with lattice QCD calculations. In the QCD analysis of the world data the first moment of the gluon spin distribution was found with a large error. Also, a search for a non-perturbative anomaly at high x was done on the world

Nucleon parton distributions in chiral perturbation theory

International Nuclear Information System (INIS)

Moiseeva, Alena

2013-01-01

Properties of the chiral expansion of nucleon light-cone operators have been studied. In the framework of the chiral perturbation theory we have demonstrated that convergency of the chiral expansion of nucleon parton distributions strongly depends on the value of the variable x. Three regions in x with essentially different analytical properties of the resulting chiral expansion for parton distributions were found. For each of the regions we have elaborated special power counting rules corresponding to the partial resummation of the chiral series. The nonlocal effective operators for the vector and the axial nucleon parton distributions have been constructed at the zeroth and the first chiral order. Using the derived nonlocal operators and the derived power counting rules we have obtained the second order expressions for the nucleon GPDs H(x,ξ,Δ 2 ), H(x,ξ,Δ 2 ),E(x,ξ,Δ 2 ) valid in the region x>or similar a 2 χ .

Nucleon exchange and heat partition in damped collisions

International Nuclear Information System (INIS)

Planeta, R.; Kwiatkowski, K.; Zhou, S.H.; Viola, V.E.; Breuer, H.; McMahan, M.A.; Randrup, J.; Mignerey, A.C.

1989-01-01

Mass and charge distributions have been measured for damped projectile-like fragments in the reaction /sup 74/Ge+/sup 165/Ho at 8.5 MeV per nucleon bombarding energy. Coincidences were measured between angle-correlated reaction partners in order to derive the primary mass distribution and the excitation energy distribution for projectile-like fragments. The evolution of the primary N and Z distributions as a function of energy loss is found to deviate significantly from predictions of the nucleon exchange transport model. The fraction of excitation energy residing in the projectile-like fragment is shown to depend both upon energy loss and the direction of the nucleon flow

Energy and system size dependence of phi meson production in Cu+Cu and Au+Au collisions

Energy Technology Data Exchange (ETDEWEB)

STAR Coll

2008-10-28

We study the beam-energy and system-size dependence of {phi} meson production (using the hadronic decay mode {phi} {yields} K{sup +}K{sup -}) by comparing the new results from Cu + Cu collisions and previously reported Au + Au collisions at {radical}s{sub NN} = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented are from midrapidity (|y| < 0.5) for 0.4 < p{sub T} < 5 GeV/c. At a given beam energy, the transverse momentum distributions for {phi} mesons are observed to be similar in yield and shape for Cu + Cu and Au + Au colliding systems with similar average numbers of participating nucleons. The {phi} meson yields in nucleus-nucleus collisions, normalized by the average number of participating nucleons, are found to be enhanced relative to those from p + p collisions with a different trend compared to strange baryons. The enhancement for {phi} mesons is observed to be higher at {radical}s{sub NN} = 200 GeV compared to 62.4 GeV. These observations for the produced {phi}(s{bar s}) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus-nucleus collisions and cannot be alone due to canonical suppression of their production in smaller systems.

Symmetry energy of the nucleus in the relativistic Thomas-Fermi approach with density-dependent parameters

Science.gov (United States)

Haddad, S.

2017-11-01

The symmetry energy of a nucleus is determined in a local density approximation and integrating over the entire density distribution of the nucleus, calculated utilizing the relativistic density-dependent Thomas-Fermi approach. The symmetry energy is found to decrease with increasing neutron excess in the nucleus. The isovector coupling channel reduces the symmetry energy, and this effect increases with increased neutron excess. The isovector coupling channel increases the symmetry energy integral in ^{40}Ca and reduces it in ^{48}Ca, and the interplay between the isovector and the isoscalar channels of the nuclear force explains this isotope effect.

The multidimensional nucleon structure

Directory of Open Access Journals (Sweden)

Pasquini Barbara

2016-01-01

Full Text Available We discuss different kinds of parton distributions, which allow one to obtain a multidimensional picture of the internal structure of the nucleon. We use the concept of generalized transverse momentum dependent parton distributions and Wigner distributions, which combine the features of transverse-momentum dependent parton distributions and generalized parton distributions. We show examples of these functions within a phenomenological quark model, with focus on the role of the spin-spin and spin-orbit correlations of quarks.

Nucleon-nucleon interaction with quark exchange and prediction of the color van der Waals potential

International Nuclear Information System (INIS)

Osman, A.

1988-01-01

The nucleon-nucleon interaction is considered by including the color nucleon clusters. The nucleon-nucleon system is treated as a six-quark system. The obtained local potentials reduce the short-range repulsion. The resulting nucleon-nucleon potential, using a quark-quark potential, agress well with the central-force potentials. The phase shifts calculated by using these local potentials are in good agreement with those obtained from other methods. Introducing the quark-quark potential in the nucleon-nucleon interaction leads to a color van der Waals potential much stronger than that implied by experiments

Yields of clustered DNA damage induced by charged-particle radiations of similar kinetic energy per nucleon: LET dependence in different DNA microenvironments

International Nuclear Information System (INIS)

Keszenman, D.J.; Sutherland, B.M.

2010-01-01

To determine the linear energy transfer (LET) dependence of the biological effects of densely ionizing radiation in relation to changes in the ionization density along the track, we measured the yields and spectrum of clustered DNA damages induced by charged particles of different atomic number but similar kinetic energy per nucleon in different DNA microenvironments. Yeast DNA embedded in agarose in solutions of different free radical scavenging capacity was irradiated with 1 GeV protons, 1 GeV/nucleon oxygen ions, 980 MeV/nucleon titanium ions or 968 MeV/nucleon iron ions. The frequencies of double-strand breaks (DSBs), abasic sites and oxypurine clusters were quantified. The total DNA damage yields per absorbed dose induced in non-radioquenching solution decreased with LET, with minor variations in radioquenching conditions being detected. However, the total damage yields per particle fluence increased with LET in both conditions, indicating a higher efficiency per particle to induce clustered DNA damages. The yields of DSBs and non-DSB clusters as well as the damage spectra varied with LET and DNA milieu, suggesting the involvement of more than one mechanism in the formation of the different types of clustered damages.

Nucleon-nucleon partial-wave analysis to 1100 MeV

International Nuclear Information System (INIS)

Arndt, R.A.; Hyslop, J.S. III; Roper, L.D.

1987-01-01

Comprehensive analyses of nucleon-nucleon elastic-scattering data below 1100 MeV laboratory kinetic energy are presented. The data base from which an energy-dependent solution and 22 single-energy solutions are obtained consists of 7223 pp and 5474 np data. A resonancelike structure is found to occur in the 1 D 2 , 3 F 3 , 3 P 2 - 3 F 2 , and 3 F 4 - 3 H 4 partial waves; this behavior is associated with poles in the complex energy plane. The pole positions and residues are obtained by analytic continuation of the ''production'' piece of the T matrix obtained in the energy-dependent solution. The new phases differ somewhat from previously published VPIandSU solutions, especially in I = 0 waves above 500 MeV, where np data are very sparse. The partial waves are, however, based upon a significantly larger data base and reflect correspondingly smaller errors. The full data base and solution files can be obtained through a computer scattering analysis interactive dial-in (SAID) system at VPIandSU, which also exists at many institutions around the world and which can be transferred to any site with a suitable computer system. The SAID system can be used to modify solutions, plan experiments, and obtain any of the multitude of predictions which derive from partial-wave analyses of the world data base

Proton-Nucleus Elastic Cross Sections Using Two-Body In-Medium Scattering Amplitudes

Science.gov (United States)

Tripathi, R. K.; Wilson, John W.; Cucinotta, Francis A.

2001-01-01

Recently, a method was developed of extracting nucleon-nucleon (NN) cross sections in the medium directly from experiment. The in-medium NN cross sections form the basic ingredients of several heavy-ion scattering approaches including the coupled-channel approach developed at the Langley Research Center. The ratio of the real to the imaginary part of the two-body scattering amplitude in the medium was investigated. These ratios are used in combination with the in-medium NN cross sections to calculate elastic proton-nucleus cross sections. The agreement is excellent with the available experimental data. These cross sections are needed for the radiation risk assessment of space missions.

Nucleon-nucleon scattering phase shifts

International Nuclear Information System (INIS)

Bryan, R.

1978-01-01

Here are presented 0 to 800 MeV nucleon-nucleon elastic and inelastic phase parameters derived by several groups: Arndt and Roper; Hoshizaki; Bugg; Bystricky, Lechanoine, and Lehar; and Bryan, Clark, and VerWest. Resonant-like behavior appears in the 1 D 2 and 3 F 3 states above the inelastic threshold in Hoshizaki's analysis but not in Arndt and Roper's. The np data are inadequate to permit determination of the I = O phase parameters above 600 MeV. 27 references

Theoretical aspects of the nucleon-nucleon workshop

International Nuclear Information System (INIS)

Silbar, R.R.

1984-01-01

This report concentrates on the inelastic NN system from 300 to 1500 MeV. Topics covered include the visibility of quark signals, dibaryons, the model dependence of predicted NN inelasticities, and a review of how well present conventional models compare with a rapidly expanding database. The general conclusion is that there is so far no clear evidence in the NN system at intermediate energies for unconventional dibaryon resonances. Short remarks are also made concerning one theoretical contribution on elastic scattering and on new experimental results for deuteron photo-disintegration and pion-nucleon charge exchange. 11 references

The nucleon-nucleon interaction in the framework of the boson exchange model

International Nuclear Information System (INIS)

Niephaus, G.H.

1984-01-01

The aim of this thesis was the description of the nucleon-nucleon interaction in a microscopically founded model. For this the description of the 2-nucleon problem by an interacting 2-nucleon-pion system was presented. The starting point of our description was a relativistic eigenvalue equation for the system of mesons and two baryons. The interaction of the baryons with the mesons was described by interaction Hamiltonians. By the elimination of antinucleon states by means of a unitary tansformation (Foldy-Wouthuysen transformation) the interaction Hamiltonians for nucleons could be generated for the field-theoretical Lagrangian densities. The Hamiltonians for resonant baryon states were obtained by means of a simplified procedure from the corresponding Lagrangian densities. Because the determination of Lagrangian densities is not unique, for the pion-nucleon coupling two alternative Lagrangian densities were allowed. For the interaction of positive-energy nucleonic states these two coupling yield nearly equal results; the production or annihilation of negative-energy nucleon states (antiparticles) the predictions however are very different. (orig./HSI) [de

Study of the incident pion deflection in passing through atomic nucleus

International Nuclear Information System (INIS)

Strugalski, Z.; Pawlak, T.; Pluta, J.

1982-01-01

Pion-xenon nucleus collision events at 3.5 GeV/c momentum are studied in which the incident pion is deflected only, without particle production; the deflection is accompanied by emission of nucleons. The multiplicity of the protons emitted is a measure of the nuclear matter layer thickness passed by the pion. It can be concluded that: a) a definite simple relation exists between the pion deflection angle and the thickness of the nuclear matter layer traversed by this pion; b) the deflection angle of the incident pion increases in a definite manner with increasing the thickness of the nuclear matter layer traversed by this pion; c) the average kinetic energy, average longitudinal momentum and average transverse momentum of the protons emitted do not depend on the pion deflection angle

Proton and neutron polarized targets for nucleon-nucleon experiments at SATURNE II

International Nuclear Information System (INIS)

Ball, J.; Combet, M.; Sans, J.L.; Benda, B.; Chaumette, P.; Deregel, J.; Durand, G.; Dzyubak, A.P.; Gaudron, C.; Lehar, F.; Janout, Z.; Khachaturov, B.A.

1996-01-01

A SATURNE polarized target has been used for nucleon-nucleon elastic scattering and transmission experiments for 15 years. The polarized proton target is a 70 cm 3 cartridge loaded with Pentanol-2. For polarized neutron target, two cartridges loaded with 6 LiD and 6 LiH are set in the refrigerator and can be quickly inserted in the beam. First experiments using 6 Li products in quasielastic pp or pn analyzing power measurements are compared with the same observables measured in a free nucleon-nucleon scattering using polarized proton targets. Angular distribution as a function of a kinematically conjugate angle and coplanarity in nucleon-nucleon scattering is shown for different targets. (author)

Influence of neutron halo in the interaction of 6He nucleus of 35 MeV/nucleon with 197Au and 238U

International Nuclear Information System (INIS)

Perier, Yann

1997-01-01

In this study, we have attempted to answer some of the questions still open concerning neutron halo nuclei. The interest of the latter lies in their very peculiar structure. The analysis of the kinematical features of the halo nucleus fragments originating from the dissociation following the interaction with a target nucleus is an essential tool for probing this structure. We studied the 6 He + Au, U at 35 A.MeV system with a new method. Simultaneous measurements of the halo nucleus core, the halo neutrons and the excitation energy deposited in the target nucleus assessed with ORION allowed us to obtain information about the formation of the 5 He nucleus and about the partial validity of the sudden approximation at moderate bombarding energy. The study of the core nucleus and neutron angular distributions confirmed that it is difficult to extract information on the internal structure at the halo neutrons from their widths. The halo neutron longitudinal momentum distributions were studied. Their widths were found to increase as the impact parameter decreases. The 4 He - core parallel momentum distributions were also investigated. The widths are weakly dependent on the excitation energy deposited in the target nucleus, but increase with the 4 He emission angle as for the halo neutrons. The ratio between one- and two-neutron stripping cross sections seems to indicate that the two halo neutrons are strongly correlated with a large dineutron component, as ascertained by a calculation in the framework of the Serber model. (author)

On light cluster production in nucleon induced reactions at intermediate energy

Energy Technology Data Exchange (ETDEWEB)

Lacroix, D.; Blideanu, V.; Durand, D

2004-09-01

A dynamical model dedicated to nucleon induced reaction between 30-150 MeV is presented. It considers different stages of the reaction: the approaching phase, the in-medium nucleon-nucleon collisions, the cluster formation and the secondary de-excitation process. The notions of influence area and phase-space exploration during the reaction are introduced. The importance of the geometry of the reaction and of the conservation laws are underlined. The model is able to globally reproduce the absolute cross sections for the emission of neutron and light charged particles for proton and neutron induced reactions on heavy and intermediate mass targets ({sup 56}Fe and {sup 208}Pb). (authors)

On light cluster production in nucleon induced reactions at intermediate energy

International Nuclear Information System (INIS)

Lacroix, D.; Blideanu, V.; Durand, D.

2004-09-01

A dynamical model dedicated to nucleon induced reaction between 30-150 MeV is presented. It considers different stages of the reaction: the approaching phase, the in-medium nucleon-nucleon collisions, the cluster formation and the secondary de-excitation process. The notions of influence area and phase-space exploration during the reaction are introduced. The importance of the geometry of the reaction and of the conservation laws are underlined. The model is able to globally reproduce the absolute cross sections for the emission of neutron and light charged particles for proton and neutron induced reactions on heavy and intermediate mass targets ( 56 Fe and 208 Pb). (authors)

Nucleon parton distributions in a light-front quark model

International Nuclear Information System (INIS)

Gutsche, Thomas; Lyubovitskij, Valery E.; Schmidt, Ivan

2017-01-01

Continuing our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity-independent and the helicity-dependent parton distributions, analytically matching the results of global fits at the initial scale μ∝ 1 GeV; they also contain the correct Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution. We also calculate the transverse parton, Wigner and Husimi distributions from a unified point of view, using our light-front wave functions and expressing them in terms of the parton distributions q_v(x) and δq_v(x). Our results are very relevant for the current and future program of the COMPASS experiment at SPS (CERN). (orig.)

Nucleon parton distributions in a light-front quark model

Energy Technology Data Exchange (ETDEWEB)

Gutsche, Thomas [Universitaet Tuebingen, Institut fuer Theoretische Physik, Kepler Center for Astro and Particle Physics, Tuebingen (Germany); Lyubovitskij, Valery E. [Universitaet Tuebingen, Institut fuer Theoretische Physik, Kepler Center for Astro and Particle Physics, Tuebingen (Germany); Tomsk State University, Department of Physics, Tomsk (Russian Federation); Tomsk Polytechnic University, Laboratory of Particle Physics, Mathematical Physics Department, Tomsk (Russian Federation); Universidad Tecnica Federico Santa Maria, Departamento de Fisica y Centro Cientifico Tecnologico de Valparaiso (CCTVal), Valparaiso (Chile); Schmidt, Ivan [Universidad Tecnica Federico Santa Maria, Departamento de Fisica y Centro Cientifico Tecnologico de Valparaiso (CCTVal), Valparaiso (Chile)

2017-02-15

Continuing our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity-independent and the helicity-dependent parton distributions, analytically matching the results of global fits at the initial scale μ∝ 1 GeV; they also contain the correct Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution. We also calculate the transverse parton, Wigner and Husimi distributions from a unified point of view, using our light-front wave functions and expressing them in terms of the parton distributions q{sub v}(x) and δq{sub v}(x). Our results are very relevant for the current and future program of the COMPASS experiment at SPS (CERN). (orig.)

anti K-nucleon interactions

Energy Technology Data Exchange (ETDEWEB)

Chand, Ramesh

1963-10-15

Total scattering and absorption cross sections for anti K-nucleon collisions in I = 1, p_3/2 - channel are given as functions of the two sets of energy dependent anti KN scattering parameters solutions, called solution A' and solution B'. These scattering parameters are obtained by linear interpolations between Watson's amplitudes around 400 MeV/c and the amplitude at the position of the pole in the anti KN scattering amplitude corresponding to the p_3/2-wave 1385 MeV Y₁-resonance with 50 MeV width. The zero-range expansion for p-wave anti K-nucleon phase shift and the scattering parameters of Watson's solution B are found to be in violation of the requirements of causality and of positive definiteness of transition probabilities. (auth)

A hadron-nucleus collision event generator for simulations at intermediate energies

CERN Document Server

Ackerstaff, K; Bollmann, R

2002-01-01

Several available codes for hadronic event generation and shower simulation are discussed and their predictions are compared to experimental data in order to obtain a satisfactory description of hadronic processes in Monte Carlo studies of detector systems for medium energy experiments. The most reasonable description is found for the intra-nuclear-cascade (INC) model of Bertini which employs microscopic description of the INC, taking into account elastic and inelastic pion-nucleon and nucleon-nucleon scattering. The isobar model of Sternheimer and Lindenbaum is used to simulate the inelastic elementary collisions inside the nucleus via formation and decay of the DELTA sub 3 sub 3 -resonance which, however, limits the model at higher energies. To overcome this limitation, the INC model has been extended by using the resonance model of the HADRIN code, considering all resonances in elementary collisions contributing more than 2% to the total cross-section up to kinetic energies of 5 GeV. In addition, angular d...

Solitary wave exchange potential and nucleon-nucleon interaction

International Nuclear Information System (INIS)

Prema, K.; Raghavan, S.S.; Sekhar Raghavan

1986-11-01

Nucleon-nucleon interaction is studied using a phenomenological potential model called solitary wave exchange potential model. It is shown that this simple model reproduces the singlet and triplet scattering data and the deuteron parameters reasonably well. (author). 6 refs, 2 figs, 1 tab

Nucleon-nucleon scattering in the functional quantum theory of the non-linear spinor field

International Nuclear Information System (INIS)

Philipp, W.

1975-01-01

The nucleon-nucleon and nucleon-antinucleon scattering cross sections are calculated in the frame of the functional quantum field theory by means of two different approximation methods: averaging by integration of indefinite integrals and pulse averaging. The results for nucleon-nucleon scattering are compared with experimental data, with calculations using a modified functional scalar product and with results in first order perturbation theory (V-A-coupling). As for elastic nucleon-antinucleon scattering, the S matrix is investigated for crossing symmetry. Scattering of 'nucleons' of different mass results in different cross sections even in the lowest-order approximation. (BJ) [de

Backward emission in hadron-nucleus collisions

International Nuclear Information System (INIS)

Stelte, N.; Weiner, R.

1981-01-01

Backward emission of hadrons in reactions of the type: P + T → a + anything, where the projectile P is a hadron, T a nuclear target and a a hadron or a light nucleus has been the subject of experimental investigation in the last decade in an energy range E starting in the hundred MeV region and extending up to 400 GeV projectile energy. The main interest in these reactions lies in the fact that they provide information about collective behavior of nucleons in nuclei (cumulative effect, i.e., the presence of secondary particles in a region of momentum space which cannot be populated by nucleon-nucleon interactions) although some authors have recently patronized this effect. In particular the consequences of nuclear limiting fragementation together with the cumulative effect can be used to obtain important information on transport properties and the equation of state of nuclear matter. Limiting fragmentation is a phenomenon discovered in the GeV region and applied to the reaction implies that in the high E limit two separate rapidity regions exist, one for the projectile and another for the target so that in each of the regions the inclusive cross section dsigma/dEd Ω becomes independent of the incoming energy. Here E and Ω refer to the kinetic energy and solid angle of the emitted particle

Local and non-local potentials for deuteron elastic scattering

International Nuclear Information System (INIS)

Ramirez, J.A.

1976-01-01

The nucleon--nucleus local potential (central and spin--orbit) and the deuteron--nucleus nonlocal potential (central, spin--orbit, spin--radial tensor) are calculated by the folding-model (FM). Simple analytic expressions are obtained for the nucleon--nucleus potential by the use of Gaussians to represent the nucleon--nucleus potential and the charge and mass densities of the target. The analytic expressions give qualitative descriptions of phenomenological nucleon--nucleus interactions. A systematic target--mass dependence of realistic local FM deueron potentials is also included. Local-equivalent, energy-dependent, deuteron potentials are obtained from the nonlocal FM deuteron potentials and the energy dependence of the local potential parameters are presented. The local FM deuteron potential is tested for 60 Ni(d,d) 60 Ni at E/sub α/ = 15 MeV by comparing the predictions of the FM potentials with data in which all five polarization moments were measured. A qualitative fit to the data is obtained, but it overestimates the volume integral of the central potential by 7%. Energy-dependence effects are estimated by evaluating the local-equivalent potentials at E/sub α/ = 30 MeV and comparing the predictions to the E/sub α/ = 15 MeV potentials. The energy dependence of the central potential dominates the angular dependence of all five observables while the energy dependence of the spin--orbit and tensor potentials produces only scale changes (approx. 3%) in the vector and tensor analyzing powers. The scattering formalism for a spin-1 on a spin-0 target nucleus, and a description of the coupled--channels computer code DDUNC1 which treats the spin--radial tensor potential exactly, are included

An upgraded version of the nucleon meson transport code: NMTC/JAERI97

Energy Technology Data Exchange (ETDEWEB)

Takada, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yoshizawa, Nobuaki; Kosako, Kazuaki; Ishibashi, Kenji

1998-02-01

The nucleon-meson transport code NMTC/JAERI is upgraded to NMTC/JAERI97 which has new features not only in physics model and nuclear data but also in computational procedure. NMTC/JAERI97 implements the following two new physics models: an intranuclear cascade model taking account of the in-medium nuclear effects and the preequilibrium calculation model based on the exciton one. For treating the nucleon transport process more accurately, the nucleon-nucleus cross sections are revised to those derived by the systematics of Pearlstein. Moreover, the level density parameter derived by Ignatyuk is included as a new option for particle evaporation calculation. Other than those physical aspects, a new geometry package based on the Combinatorial Geometry with multi-array system and the importance sampling technique are implemented in the code. Tally function is also employed for obtaining such physical quantities as neutron energy spectra, heat deposition and nuclide yield without editing a history file. The resultant NMTC/JAERI97 is tuned to be executed on the UNIX system. This paper explains about the function, physics models and geometry model adopted in NMTC/JAERI97 and guides how to use the code. (author)

Model dependence of the 2H electric dipole moment

International Nuclear Information System (INIS)

Afnan, I. R.; Gibson, B. F.

2010-01-01

Background: Direct measurement of the electric dipole moment (EDM) of the neutron is in the future; measurement of a nuclear EDM may well come first. The deuteron is one nucleus for which exact model calculations are feasible. Purpose: We explore the model dependence of deuteron EDM calculations. Methods: Using a separable potential formulation of the Hamiltonian, we examine the sensitivity of the deuteron EDM to variation in the nucleon-nucleon interaction. We write the EDM as the sum of two terms, the first depending on the target wave function with plane-wave intermediate states, and the second depending on intermediate multiple scattering in the 3 P 1 channel, the latter being sensitive to the off-shell behavior of the 3 P 1 amplitude. Results: We compare the full calculation with the plane-wave approximation result, examine the tensor force contribution to the model results, and explore the effect of short-range repulsion found in realistic, contemporary potential models of the deuteron. Conclusions: Because one-pion exchange dominates the EDM calculation, separable potential model calculations will provide an adequate description of the 2 H EDM until such time as a measurement better than 10% is obtained.

Investigation of the nucleon-nucleon tensor force in three-nucleon system

Energy Technology Data Exchange (ETDEWEB)

Clajus, M.; Egun, P.M.; Gruebler, W.; Hautle, P. (Eidgenoessische Technische Hochschule, Zurich (Switzerland). Inst. fuer Mittelenergiephysik); Slaus, I. (Institut Rudjer Boskovic, Zagreb (Yugoslavia)); Vuaridel, B. (Michigan Univ., Ann Arbor (USA) Brookhaven National Lab., Upton, NY (USA)); Sperisen, F. (Indiana Univ., Bloomington (USA). Cyclotron Facility); Kretschmer, W.; Rauscher, A.; Schuster, W.; Weidmann, R.; Haller, M. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.)); Bruno, M.; Cannata, F.; D' Agostino, M. (Istituto Nazionale di Fisica Nucleare, Bologna (Italy)); Witala, H.; Cornelius, T.; Gloeckle, W. (Bochum Univ. (Germany, F.R.)); Schmelzbach, P.A. (Paul Scherrer Inst., Villigen (Switzerland))

1990-08-16

Proton-deuteron elastic scattering has been investigated at E{sub p}=22.7 MeV by comparison of rigorous Faddeev calculations with experimental results. The observable most sensitive to the tensor force is the nucleon-nucleon polarization transfer coefficient K{sub y}sup(y'). The new angular distribution of K{sub y}sup(y') clearly favours the tensor force of the Bonn A potential, which is weaker than the one of the Paris potential. (orig.).

Toy model for pion production in nucleon-nucleon collisions

International Nuclear Information System (INIS)

Hanhart, C.; Miller, G. A.; Myhrer, F.; Sato, T.; Kolck, U. van

2001-01-01

We develop a toy model for pion production in nucleon-nucleon collisions that reproduces some of the features of the chiral Lagrangian calculations. We calculate the production amplitude and examine some common approximations

Parity violation in nuclei: studies of the weak nucleon-nucleon interaction

International Nuclear Information System (INIS)

Mcdonald, A.B.

1980-03-01

The Weinberg-Salam Unified Model of weak and electromagnetic interactions has been very successful in explaining parity violation and neutral current effects in neutrino-nucleon, electron-nucleon and neutrino-electron interactions. A wide variety of nuclear physics parity violation experiments are in progress to measure effects of the weak nucleon-nucleon interaction in few nucleon systems and certain heavier nuclei where enhancements are expected. The current status of these experiments will be reviewed, including details of an experiment at Chalk River to search for parity violation in the photodisintegration of deuterium and an extension of our previous measurements of parity mixing in 21 Ne. The interpretation of results in terms of basic models of the weak interaction will be discussed. (Auth)

Spin of two-nucleon system and nucleon-antinucleon combination in the S-state

International Nuclear Information System (INIS)

Baranik, A.T.; El-Naghy, A.; Ramadan, S.

1988-08-01

The spin of the two nucleon combination was studied. It was found that the resultant combination could be treated as a boson with spin one or zero, and the spin one state is more stable than the spin zero state. In the case of nucleon-antinucleon combination the spin zero state is more stable than the spin one state. The approach succeeded in describing the general features of the nucleon-nucleon and nucleon antinucleon scattering and polarization. (author). 3 refs, 4 figs

Shear viscosity of neutron-rich nucleonic matter near its liquid–gas phase transition

International Nuclear Information System (INIS)

Xu, Jun; Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An; Ma, Yu Gang

2013-01-01

Within a relaxation time approach using free nucleon–nucleon cross sections modified by the in-medium nucleon masses that are determined from an isospin- and momentum-dependent effective nucleon–nucleon interaction, we investigate the specific shear viscosity (η/s) of neutron-rich nucleonic matter near its liquid–gas phase transition. It is found that as the nucleonic matter is heated at fixed pressure or compressed at fixed temperature, its specific shear viscosity shows a valley shape in the temperature or density dependence, with the minimum located at the boundary of the phase transition. Moreover, the value of η/s drops suddenly at the first-order liquid–gas phase transition temperature, reaching as low as 4–5 times the KSS bound of ℏ/4π. However, it varies smoothly for the second-order liquid–gas phase transition. Effects of the isospin degree of freedom and the nuclear symmetry energy on the value of η/s are also discussed

Pionic background for nucleon-nucleon observables

International Nuclear Information System (INIS)

Ballot, J.L.; Robilotta, M.R.

1992-01-01

A method is presented that allows the unambiguous definition of the one pion exchange contribution to nucleon-nucleon scattering observables and then use it to determine those waves where values of phase shifts and mixing parameters may be understood as sums of pionic and non-pionic dynamical effects. This helps the assessment of the explicative power of the various existing phenomenological potentials and may eventually lead to ways of discriminating their effectiveness. (author) 16 refs.; 19 figs.; 2 tabs

Nucleon-nucleon interaction of a chiral σ-ω model at finite temperature

International Nuclear Information System (INIS)

Rukeng Su

1994-01-01

By using the imaginery time Green's function method, the nucleon-nucleon interaction of the chiral σ-ω model has been investigated under the one-loop approximation. The effective masses of the pion, σ-meson and ω-meson at finite temperature are given. We have found that the potential well of the nucleon-nucleon interaction becomes shallow as the temperature increases. At a critical temperature T c (70 MEV) the potential well disappears. (author)

Measurement of the Production Cross Section for the Charmed Baryon $\\Lambda_c$ in 250 GeV/c Pion-Nucleon Interactions

Energy Technology Data Exchange (ETDEWEB)

dos Reis, Alberto Correa [Rio de Janeiro, CBPF

1992-04-01

This work a presents a measurement of the total cross section for the charmed baryon $\\Lambda_c$ times the branching fraction of the mode $\\Lambda_c \\to pK\\bar{\\mu}$, for the kinematical region $x_F$ > O in $\\pi$-nucleus interactions at 250 GeV/c. This measurement is made with data from the experiment E769, collected during 1987/1988 at the FERMILAB Tagged Photon Laboratory. A segmented target of berillium, aluminum, copper and tungsten was used. Based on the A dependence measurement, made by E769, and on the available branching fractions, the total cross section per nucleon is calculated. The result is compared with other experiments and with some theoretical predictions inspired on QCD.

A new potential of π-nucleus scattering and its application to nuclear structure study using elastic scattering and charge exchange reactions

International Nuclear Information System (INIS)

Durand, Gerard.

1974-01-01

First the different theories used for studying pion-nucleus scattering and especially Glauber microscopic model and Kisslinger optical model are summarized. From the comparison of these two theories it was concluded that Kisslinger's was better for studying pion-nucleus scattering near the (3/2-3/2) resonance. The potential was developed, with a local corrective term, proposed by this author. This new term arises from taking into account correctly the Lorentz transformation from the pion-nucleon center of mass to the pion nucleus center of mass system. A coupled-channel formalism was developed allowing the study of pion-nucleus elastic scattering and also the study of single and double charge exchange reactions on nucleus with N>Z. The influence of the new term and the shape of nucleon densities on π- 12 C scattering was studied near 200MeV. It was found that at the nucleus surface the neutron density was larger than the proton density. On the other hand, a maximum of sensibility to the different nuclear parameters was found near 180MeV and for elastic scattering angles greater than 100 deg. The calculations of the total cross section for simple and double charge exchange for 13 C and 63 Cu yielded results simular to those of previous theories and showed the same discrepancy between theory and experiment in the resonance region [fr

Asymmetry dependence of nucleon correlations in spherical nuclei extracted from a dispersive-optical-model analysis

International Nuclear Information System (INIS)

Mueller, J. M.; Shane, R.; Waldecker, S. J.; Dickhoff, W. H.; Charity, R. J.; Sobotka, L. G.; Crowell, A. S.; Esterline, J. H.; Fallin, B.; Howell, C. R.; Westerfeldt, C.; Youngs, M.; Crowe, B. J. III; Pedroni, R. S.

2011-01-01

Neutron elastic-scattering angular distributions were measured at beam energies of 11.9 and 16.9 MeV on 40,48 Ca targets. These data plus other elastic-scattering measurements, total and reaction cross-sections measurements, (e,e ' p) data, and single-particle energies for magic and doubly magic nuclei have been analyzed in the dispersive optical-model (DOM), generating nucleon self-energies (optical-model potentials) that can be related, via the many-body Dyson equation, to spectroscopic factors and occupation probabilities. It is found that, for stable nuclei with N≥Z, the imaginary surface potential for protons exhibits a strong dependence on the neutron-proton asymmetry. This result leads to a more modest dependence of the spectroscopic factors on asymmetry. The measured data and the DOM analysis of all considered nuclei clearly demonstrate that the neutron imaginary surface potential displays very little dependence on the neutron-proton asymmetry for nuclei near stability (N≥Z).

The study of the components of matter collective flow in the collisions of {sup 64} Zn on {sup 58} Ni at 35 to 79 MeV/u; Etude des composantes de l`ecoulement collectif de matiere dans les collisions {sup 64} Zn sur {sup 58} Ni de 35 a 79 MeV/u

Energy Technology Data Exchange (ETDEWEB)

Popescu, R [Caen Univ., 14 (France). Lab. de Physique Corpusculaire

1995-06-01

In a nucleus-nucleus collision the collective motion of matter, emitted from the overlapping region, give information on the properties of nuclear matter out-of-equilibrium. The characteristics of this motion have been studied on the {sup 64} Zn on {sup 58} Ni system up to 79 MeV per nucleon, using the flow parameter and the azimuthal distributions. We studied the evolution of those quantities with the incident energy, the impact parameter and the charge of particle. The experiment has been done at GANIL using the multidetectors of light particles and fragments, Mur and Tonneau. For estimating the impact parameter, two global variables have been used: the average parallel velocity and the total perpendicular momentum. For determining the reaction plane two methods have been used: the transverse momentum analysis and the azimuthal correlation method. The results are not sensitive to the global variable or method. The measured values revealed the inversion of the direction of sideward flow. The energy of vanishing flow ranges from 55 to 75 MeV per nucleon when the impact parameter increases from 1 to 6 fm. In the same way, the aspect of the azimuthal distribution changes from in-plane to out-of-plane enhancement when the energy increases, providing with a new indication of change in the interaction dynamics. The energy of isotropic emission lies between 45 and 65 MeV per nucleon depending of the impact parameter. For alpha particles, the flow parameter and the azimuthal asymmetry are greater than for protons, due to a smaller thermal dispersion. A Landau-Vlasov model using a non-local Gogny force is able to reproduce the global characteristics experimentally observed (rapidity and transverse momentum distributions). The calculated flow and azimuthal asymmetry values reproduce the experimental ones for an incompressibility modulus near 230 MeV. The study of the dependence on nucleon-nucleon cross section in nuclear medium must be pursued. (author) 37 refs.

The study of the components of matter collective flow in the collisions of 64 Zn on 58 Ni at 35 to 79 MeV/u

International Nuclear Information System (INIS)

Popescu, R.

1995-06-01

In a nucleus-nucleus collision the collective motion of matter, emitted from the overlapping region, give information on the properties of nuclear matter out-of-equilibrium. The characteristics of this motion have been studied on the 64 Zn on 58 Ni system up to 79 MeV per nucleon, using the flow parameter and the azimuthal distributions. We studied the evolution of those quantities with the incident energy, the impact parameter and the charge of particle. The experiment has been done at GANIL using the multidetectors of light particles and fragments, Mur and Tonneau. For estimating the impact parameter, two global variables have been used: the average parallel velocity and the total perpendicular momentum. For determining the reaction plane two methods have been used: the transverse momentum analysis and the azimuthal correlation method. The results are not sensitive to the global variable or method. The measured values revealed the inversion of the direction of sideward flow. The energy of vanishing flow ranges from 55 to 75 MeV per nucleon when the impact parameter increases from 1 to 6 fm. In the same way, the aspect of the azimuthal distribution changes from in-plane to out-of-plane enhancement when the energy increases, providing with a new indication of change in the interaction dynamics. The energy of isotropic emission lies between 45 and 65 MeV per nucleon depending of the impact parameter. For alpha particles, the flow parameter and the azimuthal asymmetry are greater than for protons, due to a smaller thermal dispersion. A Landau-Vlasov model using a non-local Gogny force is able to reproduce the global characteristics experimentally observed (rapidity and transverse momentum distributions). The calculated flow and azimuthal asymmetry values reproduce the experimental ones for an incompressibility modulus near 230 MeV. The study of the dependence on nucleon-nucleon cross section in nuclear medium must be pursued. (author)

Predicting the optical observables for nucleon scattering on even-even actinides

Science.gov (United States)

Martyanov, D. S.; Soukhovitskiĩ, E. Sh.; Capote, R.; Quesada, J. M.; Chiba, S.

2017-09-01

The previously derived Lane consistent dispersive coupled-channel optical model for nucleon scattering on 232Th and 238U nuclei is extended to describe scattering on even-even actinides with Z = 90-98. A soft-rotator-model (SRM) description of the low-lying nuclear structure is used, where the SRM Hamiltonian parameters are adjusted to the observed collective levels of the target nucleus. SRM nuclear wave functions (mixed in K quantum number) have been used to calculate the coupling matrix elements of the generalized optical model. The “effective” deformations that define inter-band couplings are derived from the SRM Hamiltonian parameters. Conservation of nuclear volume is enforced by introducing a dynamic monopolar term to the deformed potential, leading to additional couplings between rotational bands. The fitted static deformation parameters are in very good agreement with those derived by Wang and collaborators using the Weizsäcker-Skyrme global mass model (WS4), allowing use of the latter to predict cross sections for nuclei without experimental data. A good description of the scarce “optical” experimental database is achieved. SRM couplings and volume conservation allow a precise calculation of the compound-nucleus formation cross sections, which is significantly different from that calculated with rigid-rotor potentials coupling the ground-state rotational band. The derived parameters can be used to describe both neutron- and proton-induced reactions. Supported by International Atomic Energy Agency, through the IAEA Research Contract 19263, by the Spanish Ministry of Economy and Competitivity under Contracts FPA2014-53290-C2-2-P and FPA2016-77689-C2-1-R.

Nucleon Spin Structure: Longitudinal and Transverse

International Nuclear Information System (INIS)

Chen, Jian-Ping

2011-01-01

Inclusive Deep-Inelastic Scattering (DIS) experiments have provided us with the most extensive information on the unpolarized and longitudinal polarized parton (quark and gluon) distributions in the nucleon. It has becoming clear that transverse spin and transverse momentum dependent distributions (TMDs) study are crucial for a more complete understanding of the nucleon structure and the dynamics of the strong interaction. The transverse spin structure and the TMDs are the subject of increasingly intense theoretical and experimental study recently. With a high luminosity electron beam facility, JLab has played a major role in the worldwide effort to study both the longitudinal and transverse spin structure. Highlights of recent results will be presented. With 12-GeV energy upgrade, JLab will provide the most precise measurements in the valence quark region to close a chapter in longitudinal spin study. JLab will also perform a multi-dimensional mapping of the transverse spin structure and TMDs in the valence quark region through Semi-Inclusive DIS (SIDIS) experiments, providing a 3-d partonic picture of the nucleon in momentum space and extracting the u and d quark tensor charges of the nucleon. The precision mapping of TMDs will also allow a detailed study of the quark orbital motion and its dynamics.

Two-current nucleon observables in Skyrme model

International Nuclear Information System (INIS)

Chemtob, M.

1987-01-01

Three independent two-current nucleon observables are studied within the two-flavor Skyrme model for the πρω system. The effecive lagrangian is that of the gauged chiral symmetry approach, consistent with the vector meson dominance, in the linear realization (for the vector mesons) of the global chiral symmetry. The first application deals with the nucleon electric polarizability and magnetic susceptibility. Both seagull and dispersive contributions appear and we evaluate the latter in terms of the sums over intermediate states. The results are compared with existing quark model results as well as with empirical determinations. The second application concerns the zero-point quantum correction to the skyrmion mass. We apply a chiral perturbation theory approach to evaluate the ion loop contribution to the nucleon mass. The comparison with the conventional Skyrme model result reveals an important sensitivity to the stabilization mechanism. The third application is to lepton-nucleon deep inelastic scattering in the Bjorken scaling limit. The structure tensor is calculated in terms of the representation as a commutator product of two currents. Numerical results are presented for the scaling function F 2 (x). An essential use is made of the large N c (number of colors) approximation in all these applications. In the numerical computations we ignore the distortion effects, relative to the free plane wave limit, on the pionic fluctuations. (orig.)

Calculation of the nucleon structure function from the nucleon wave function

Science.gov (United States)

Hussar, Paul E.

1993-01-01

Harmonic oscillator wave functions have played an historically important role in our understanding of the structure of the nucleon, most notably by providing insight into the mass spectra of the low-lying states. High energy scattering experiments are known to give us a picture of the nucleon wave function at high-momentum transfer and in a frame in which the nucleon is traveling fast. A simple model that crosses the twin bridges of momentum scale and Lorentz frame that separate the pictures of the nucleon wave function provided by the deep inelastic scattering data and by the oscillator model is presented.

Nucleon exchange and excitation energy division in damped collisions

International Nuclear Information System (INIS)

Viola, V.E.; Planeta, R.; Kwiatkowski, K.; Zhou, S.H.; Breuer, H.

1989-01-01

In this paper we will examine both the dependence of nucleon exchange on target-projectile properties and the question of temperature equilibration and heat partition during scission. Primary emphasis will be placed on the results of a recent study of the 74 Ge + 165 Ho system, which allows us to address these two questions simultaneously. The results can thus be directly compared with the predictions of the nucleon-exchange model. (author)

Anomalous transition strength in the proton-unbound nucleus {sup 109}{sub 53}I{sub 56}

Energy Technology Data Exchange (ETDEWEB)

Procter, M.G., E-mail: mark.procter@postgrad.manchester.ac.uk [School of Physics and Astronomy, Schuster Laboratory, The University of Manchester, Manchester M13 9PL (United Kingdom); Cullen, D.M. [School of Physics and Astronomy, Schuster Laboratory, The University of Manchester, Manchester M13 9PL (United Kingdom); Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland); Scholey, C.; Ruotsalainen, P. [Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland); Angus, L. [University of The West of Scotland, High Street, Paisley PA1 2BE (United Kingdom); Baeck, T.; Cederwall, B. [Department of Physics, Royal Institute of Technology, SE-10691 Stockholm (Sweden); Dewald, A.; Fransen, C. [Institut fuer Kernphysik, Universitaet zu Koeln, D-50937, Koeln (Germany); Grahn, T. [Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland); Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Greenlees, P.T. [Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland); Hackstein, M. [Institut fuer Kernphysik, Universitaet zu Koeln, D-50937, Koeln (Germany); Jakobsson, U.; Jones, P.M.; Julin, R.; Juutinen, S.; Ketelhut, S.; Leino, M. [Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland); Liotta, R. [Department of Physics, Royal Institute of Technology, SE-10691 Stockholm (Sweden); Lumley, N.M. [School of Physics and Astronomy, Schuster Laboratory, The University of Manchester, Manchester M13 9PL (United Kingdom)

2011-10-13

A lifetime measurement has been made for the first excited 11/2{sup +} state in the proton-unbound nucleus {sup 109}{sub 53}I{sub 56} using the recoil-distance Doppler-shift method in conjunction with recoil-proton tagging. The experimental reduced transition probability is considerably smaller than the prediction of theoretical shell-model calculations using the CD-Bonn nucleon-nucleon potential. The discrepancy between the theoretical and experimental reduced transition strengths in this work most likely arises from the inability of the current shell-model calculations to accurately account for the behavior of the unbound nuclear states.

Identical bands in (even, odd) nuclei as evidence for spectator nucleons

Energy Technology Data Exchange (ETDEWEB)

Schmeing, N C [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

1992-08-01

An explanation is sought for ``identical`` moments of inertia for pairs of rotational bands in superdeformed nuclei differing in particle number. The authors postulate that certain nucleons do not participate in the collective rotation. The energy of superdeformed {sup 152}Dy has been calculated using this model with a deformed Woods-Saxon potential and full mixing of oscillator shells. A significant reduction in energy is achieved when the protons and neutron with asymptotic quantum number N < 4 constitute a nonrotating factor, as compared to the conventional prolate nucleus. 9 refs.

The nucleon-nucleon interaction from a realistic pseudoscalar-vector chiral lagrangian

International Nuclear Information System (INIS)

Kaiser, N.; Meissner, U.G.; Massachusetts Inst. of Tech., Cambridge

1990-01-01

We investigate the static nucleon-nucleon potential in the framework of a non-linear chiral meson theory. The model includes pions as well as the vector mesons ρ and ω. All parameters are fixed in the meson sector and predictions about the nucleon-nucleon interaction follow without adjusting any parameters. We use an S-matrix approach to calculate correlated two-pion exchange between two solitons. The most prominent feature of this two-pion exchange is that it leads very natural to attraction in the scalar-isoscalar channel. We also discuss the effect of πp correlations on the central potential, and present the spectral function related to the correlated two-pion exchange. Furthermore, we study the form factors of the nucleon sources related to the two-pion exchange and find that they are of dipole type with typical cutoff scales Λ D ≅ 700 MeV. We also discuss the destructive interference of π- and ρ-exchange in the isovector tensor potential. Altogether, we present a unified treatment of meson exchange phenomenology based on a serious model of the nucleon. Finally, we point out the limitations of the model and discuss some further applications. (orig.)

Low-energy particle production and residual nuclei production from high-energy hadron-nucleus collisions

International Nuclear Information System (INIS)

Alsmiller, F.S.; Alsmiller, R.G. Jr.; Hermann, O.W.

1987-01-01

The high-energy hadron-nucleus collision model, EVENTQ, has been modified to include a calculation of the excitation and kinetic energy of the residual compound nucleus. The specific purpose of the modification is to make it possible to use the model in the high-energy radiation transport code, HETC, which, in conjunction with MORSE, is used to transport the low energy particles. It is assumed that the nucleons in the nucleus move in a one-dimensional potential well and have the momentum distribution of a degenerate Fermi gas. The low energy particles produced by the deexcitation of the residual compound nucleus, and the final residual nucleus, are determined from an evaporation model. Comparisons of multiplicities and residual nuclei distributions with experimental data are given. The ''grey'' particles, i.e., charged particles with 0.25 < β < 0.7, are in good agreement with experimental data but the residual nuclei distributions are not. 12 refs., 3 figs

Nucleon many-body problem using quantum-mechanical few-body technique

International Nuclear Information System (INIS)

Horiuchi, Wataru

2016-01-01

A nucleus is treated as a quantum-mechanical many-body system consisting of protons and neutrons that interact with each other by nuclear force. This paper explains the variational calculation using the correlated basis function as a powerful technique for obtaining the precise solution of Schroedinger equation of many-body, and tries to understand the nucleon many-body system from the viewpoint of a few-body through the application cases of various nuclear systems. It describes the important correlation that characterizes the nucleon many-body system such as the mean field, cluster, and tensor of bound state, and shows that non-bound state is also describable. Since such precise theory is mantic, it is essential for explaining the nature of unknown unstable nuclei, and for determining the nuclear reaction rate under the environment of the stars difficult for experiment. The method is general and flexible, and can be applied to various quantum-mechanical many-body problems. For example, the multi-body calculation of atoms and molecules, hypernuclei, and hadron spectroscopy can be carried out only by changing the potential and particles. (A.O.)

The nucleon axial mass and the MiniBooNE quasielastic neutrino-nucleus scattering problem

International Nuclear Information System (INIS)

Nieves, J.; Ruiz Simo, I.; Vicente Vacas, M.J.

2012-01-01

The charged-current double differential neutrino cross section, measured by the MiniBooNE Collaboration, has been analyzed using a microscopical model that accounts for, among other nuclear effects, long range nuclear (RPA) correlations and multinucleon scattering. We find that MiniBooNE data are fully compatible with the world average of the nucleon axial mass in contrast with several previous analyses which have suggested an anomalously large value. We also discuss the reliability of the algorithm used to estimate the neutrino energy.

Induced Hyperon-Nucleon-Nucleon Interactions and the Hyperon Puzzle.

Science.gov (United States)

Wirth, Roland; Roth, Robert

2016-10-28

We present the first ab initio calculations for p-shell hypernuclei including hyperon-nucleon-nucleon (YNN) contributions induced by a similarity renormalization group transformation of the initial hyperon-nucleon interaction. The transformation including the YNN terms conserves the spectrum of the Hamiltonian while drastically improving model-space convergence of the importance-truncated no-core model, allowing a precise extraction of binding and excitation energies. Results using a hyperon-nucleon interaction at leading order in chiral effective field theory for lower- to mid-p-shell hypernuclei show a good reproduction of experimental excitation energies while hyperon separation energies are typically overestimated. The induced YNN contributions are strongly repulsive and we show that they are related to a decoupling of the Σ hyperons from the hypernuclear system, i.e., a suppression of the Λ-Σ conversion terms in the Hamiltonian. This is linked to the so-called hyperon puzzle in neutron-star physics and provides a basic mechanism for the explanation of strong ΛNN three-baryon forces.

Nucleon Resonance Physics

Energy Technology Data Exchange (ETDEWEB)

Burkert, Volker D.

2016-07-25

Recent results of meson photo-production at the existing electron machines with polarized real photon beams and the measurement of polarization observables of the final state baryons have provided high precision data that led to the discovery of new excited nucleon and $\\Delta$ states using multi-channel partial wave analyses procedures. The internal structure of several prominent excited states has been revealed employing meson electroproduction processes. On the theoretical front, lattice QCD is now predicting the baryon spectrum with very similar characteristics as the constituent quark model, and continuum QCD, such as is represented in the Dyson-Schwinger Equations approach and in light front relativistic quark models, describes the non-perturbative behavior of resonance excitations at photon virtuality of $Q^2 > 1.5GeV^2$. In this talk I discuss the need to continue a vigorous program of nucleon spectroscopy and the study of the internal structure of excited states as a way to reveal the effective degrees of freedom underlying the excited states and their dependence on the distance scale probed.

Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons

International Nuclear Information System (INIS)

Sadler, M.E.; Isenhower, L.D.

1992-01-01

This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments

Meson cloud in the nucleon and its consequences in various phenomena

International Nuclear Information System (INIS)

Szczurek, A.

1997-06-01

Consequences of the meson cloud in the nucleon and search for its evidences in various phenomena in both soft and hard processes were discussed. The cut-off parameters of the form factors (FF) for meson-baryon vertices are determined from high-energy particle production data. An universal cut-off parameter for processes involving octet baryons has been found. Relativistic calculations of the effects of the pion cloud on the electromagnetic properties of the nucleon are presented. Light-cone formalism was used to construct the nucleon wave function. The elastic electromagnetic nucleon FF G p,n E (Q 2 ) and G p,n M (Q 2 ) are computed in terms of matrix elements of current operator and the nucleon wave function. The Q 2 -dependence of contributions to the nucleon FF from the various sectors of the model space is calculated. The observed deviations from FF scaling and dipole parameterization is discussed. A set of formulae for longitudinal momentum distribution functions (splitting functions) of mesons in the nucleon has been determined. The value of the Gottfried Sum Rule obtained from model (S G =0.224) agrees with that obtained by the NMC. The calculated axial coupling constants for semileptonic decays of the octet baryons agree with the experimental data. Enhanced production of events at large x in comparison to standard sets of quark distributions with rather mild Q 2 -dependence was predicted. The semi-inclusive cross section for producing slow protons in charged current deep inelastic (anti-)neutrino scattering nucleons is calculated as a function of the x and the proton momentum. The possible consequences of the meson cloud in the nucleon for the production of the W and Z bosons in hadron-hadron collisions were discussed. A good description of the total W and Z production cross sections measured in the proton-antiproton collisions as well as the lepton asymmetry have been obtained. The model predicts an enhancement of the cross section for the W production in

Nucleon-nucleon theory and phenomenology. Progress report and renewal proposal, June 1, 1981-May 31, 1982

International Nuclear Information System (INIS)

Signell, P.

1981-01-01

This project has involved five inter-related subprojects: (1) derivation of the intermediate range nucleon-nucleon interaction using a new method that utilizes much shorter and simpler analytic continuation through the unphysical region that lies between the πN and ππ physical regions of the N anti N → ππ amplitude (with signifantly improved accuracy for the nucleon-nucleon interaction); (2) construction of a short range phenomenological potential that, with the theoretical part mentioned above, gives a precise fit to the nucleon-nucleon data and is parameterized for easy use in nucleon calculations; (3) phase shift analyses of the world data below 400 MeV, especially the large amount of very precise data below 20 meV and the new data near 55 MeV that have never been analyzed properly; (4) the introduction of a K-matrix formulation of the Optimal Polynomial Expansion in order to accelerate convergence of the partial wave series at LAMPF energies; and (5) setting up of a cooperatively evaluated permanent nucleon-nucleon data bank in the 1-1200 MeV range that can be used by all nucleon-nucleon researchers

Resonance estimates for single spin asymmetries in elastic electron-nucleon scattering

International Nuclear Information System (INIS)

Barbara Pasquini; Marc Vanderhaeghen

2004-01-01

We discuss the target and beam normal spin asymmetries in elastic electron-nucleon scattering which depend on the imaginary part of two-photon exchange processes between electron and nucleon. We express this imaginary part as a phase space integral over the doubly virtual Compton scattering tensor on the nucleon. We use unitarity to model the doubly virtual Compton scattering tensor in the resonance region in terms of γ* N → π N electroabsorption amplitudes. Taking those amplitudes from a phenomenological analysis of pion electroproduction observables, we present results for beam and target normal single spin asymmetries for elastic electron-nucleon scattering for beam energies below 1 GeV and in the 1-3 GeV region, where several experiments are performed or are in progress

Unified semimicroscopic approach scattering of low energy protons and alpha-particles by nuclei

International Nuclear Information System (INIS)

Dao Tien Khoa; Kukhtina, I.N.; Knyaz'kov, O.M.; Feofilov, G.A.

1988-01-01

The unified approach has been developed to the description of the interaction of low energy nucleons and α-particles with nuclei. The analysis of elastic and inelastic scattering of 25.05 MeV protons and 104 MeV α-particles from 90 Zr is made. The differences in deformations of neutron and proton density distributions for 90 Zr nucleus are extracted. The energy dependence of the obtained α-particle - nucleus semimicroscopic potential is investigated, including the energy dependence for the geometry of the potential. The feaures of angular distributions of elastic α-particle scattering and the role of nucleon-nucleon correlations are analysed as a function of α-particle energy

Excitation of Nucleon Resonances

International Nuclear Information System (INIS)

Burkert, Volker D.

2001-01-01

I discuss developments in the area of nucleon resonance excitation, both necessary and feasible, that would put our understanding of nucleon structure in the regime of strong QCD on a qualitatively new level. They involve the collection of high quality data in various channels, a more rigorous approach in the search for ''missing'' resonances, an effort to compute some critical quantities in nucleon resonance excitations from first principles, i.e. QCD, and a proposal focused to obtain an understanding of a fundamental quantity in nucleon structure

The dependence of J/ψ-nucleon inelastic cross section on the Feynman variable

International Nuclear Information System (INIS)

Duan Chungui; Liu Na; Miao Wendan

2011-01-01

By means of two typical sets of nuclear parton distribution functions, meanwhile taking account of the energy loss of the beam proton and the nuclear absorption of the charmonium states traversing the nuclear matter in the uniform framework of the Glauber model, a leading order phenomenological analysis is given in the color evaporation model of the E866 experimental data on J/ψ production differential cross section ratios R Fe/Be (x F ). It is shown that the energy loss effect of beam proton on R Fe/Be (x F ) is more important than the nuclear effects on parton distribution functions in the high Feynman variable x F region. It is found that the J/ψ-nucleon inelastic cross section depends on the Feynman variable x F and increases linearly with x F in the region x F > 0.2. (authors)

Conflicting Coupling of Unpaired Nucleons and the Structure of Collective Bands in Odd-Odd Nuclei

International Nuclear Information System (INIS)

Levon, A.I.; Pasternak, A.A.

2011-01-01

The conflicting coupling of unpaired nucleons in odd-odd nuclei is discussed. A very simple explanation is suggested for the damping of the energy spacing of the lowest levels in the rotational bands in odd-odd nuclei with the 'conflicting' coupling of an odd proton and an odd neutron comparative to those of the bands based on the state of a strongly coupled particle in the neighboring odd nucleus entering the 'conflicting' configuration.

Studying the Puzzle of the Pion Nucleon Sigma Term

Science.gov (United States)

Kane, Christopher; Lin, Huey-Wen

2017-09-01

The pion nucleon sigma term (σπN) is a fundamental parameter of QCD and is integral in the experimental search for dark matter particles as it is used to calculate the cross section of interactions between potential dark matter candidates and nucleons. Recent calculations of this term from lattice-QCD data disagree with calculations done using phenomenological data. This disparity is large enough to cause concern in the dark matter community as it would change the constraints on their experiments. We investigate one potential source of this disparity by studying the flavor dependence on LQCD data used to calculate σπN. To calculate σπN, we study the nucleon mass dependence on the pion mass and implement the Hellmann-Feynman Theorem. Previous calculations only consider LQCD data that accounted for 2 and 3 of the lightest quarks in the quark sea. We extend this study by using new high statistic data that considers 2, 3, and 4 quarks in the quark sea to see if the exclusion of the heavier quarks can account for this disparity. National Science Foundation.

Inclusive negative-hadron production from high-energy nu-bar-nucleus charged-current interactions

International Nuclear Information System (INIS)

Berge, J.P.; Bogert, D.; Endorf, R.; Hanft, R.; Malko, J.A.; Moffatt, G.; Nezrick, F.A.; Scott, W.; Smart, W.; Wolfson, J.; Ammosov, V.V.; Amrakhov, A.H.; Denisov, A.G.; Ermolov, P.F.; Gapienko, V.A.; Klukhin, V.I.; Koreshev, V.I.; Pitukhin, P.V.; Rjabov, V.G.; Slobodyuk, E.A.; Sirotenko, V.I.; Efremenko, V.I.; Gorichev, P.A.; Kaftanov, V.S.; Khovansky, V.D.; Kliger, G.K.; Kolganov, V.Z.; Krutchinin, S.P.; Kubantsev, M.A.; Rosanov, A.N.; Savitsky, M.M.; Shevchenko, V.G.; Coffin, C.T.; Diamond, R.N.; French, H.; Louis, W.; Roe, B.P.; Ross, R.T.; Seidl, A.A.; Sinclair, D.

1978-01-01

We present data on inclusive negative-hadron production from charged-current antineutrino interactions in a 21% Ne--H mixture. Inclusive single-particle distributions are presented and are shown to be insensitive to the momentum transferred to the hadron vertex. Comparisons made to inclusive data from π - p and π - n interactions indicate a close similarity between the hadrons resulting from π-nucleon and nu-bar-nucleus interactions. The general features of the nu-bar-nucleus data are found to be similar to those seen in nu-barp interactions. This last observation implies that nu-barp and nu-barn interactions are similar and that nuclear effects are small

Partial inelasticity coefficients of negative pions in p, d, α, 12C + 12C and p, 12C + 181Ta collisions at 4.2 GeV/c per nucleon

International Nuclear Information System (INIS)

Olimov, K.K.; Olimov, K.; Gulamov, K.G.; Olimov, A.K.; Lutpullaev, S.L.; Yuldashev, B.S.; Haseeb, M.Q.

2015-01-01

The partial inelasticity coefficients of the negative pions were determined in minimum bias p, d, α, 12 C + 12 C and p, 12 C + 18 Ta collisions at 4.2A GeV/c taking into account the average number of participant nucleons of a projectile nucleus. In nucleus–nucleus collisions, the average values of partial inelasticity coefficients (〈K(π-)〉) of the negative pions did not depend on the mass numbers of projectile and target nuclei. Increase of 〈K(π - )〉 in going from p + 12 C to d, α, 12 C + 12 C collisions was due to an additional source of production of fast negative pions in nucleus–nucleus collisions — a charge exchange conversion of one or more neutrons of a projectile nucleus into a proton and π - . Linking the experimental results of the present analysis at intermediate energy with those obtained at high and ultra-high energies, it was concluded that the average values of partial inelasticity coefficients of pions in nucleon–nucleus and nucleus–nucleus collisions manifest a transitive behavior. At intermediate energies, the values of 〈K(π - )〉 were smaller by a factor of two and more as compared to those at high energies, and they increased further with increasing incident energy, reaching a plateau at E 0 > 100A GeV. (author)

Study of Hadron Production in Hadron-Nucleus and Nucleus-Nucleus Collisions at the CERN SPS

CERN Multimedia

Klochkov, V; Herve, A E; Kowalski, S; Kaptur, E A; Kowalik, K L; Dominik, W M; Matulewicz, T N; Krasnoperov, A; Feofilov, G; Vinogradov, L; Kovalenko, V; Johnson, S R; Planeta, R J; Rubbia, A; Marton, K; Messerly, B A; Puzovic, J; Bogomilov, M V; Bravar, A; Renfordt, R A E; Deveaux, M; Engel, R R; Grzeszczuk, A; Davis, N; Kuich, M; Lyubushkin, V; Kondratev, V; Kadija, K; Diakonos, F; Slodkowski, M A; Rauch, W H; Pistillo, C; Laszlo, A; Nakadaira, T; Hasegawa, T; Sadovskiy, A; Morozov, S; Petukhov, O; Mathes, H; Roehrich, D; Marcinek, A J; Marino, A D; Grebieszkow, K; Di luise, S; Wlodarczyk, Z; Rybczynski, M A; Wojtaszek-szwarc, A; Nirkko, M C; Sakashita, K; Golubeva, M; Kurepin, A; Manic, D; Kolev, D I; Kisiel, J E; Koziel, M E; Rondio, E; Larsen, D T; Czopowicz, T R; Seyboth, P; Turko, L; Guber, F; Marin, V; Busygina, O; Strikhanov, M; Taranenko, A; Cirkovic, M; Roth, M A; Pulawski, S M; Aduszkiewicz, A M; Bunyatov, S; Vechernin, V; Nagai, Y; Anticic, T; Dynowski, K M; Mackowiak-pawlowska, M K; Stefanek, G; Pavin, M; Fodor, Z P; Nishikawa, K; Tada, M; Blondel, A P P; Stroebele, H W; Posiadala, M Z; Kolesnikov, V; Andronov, E; Zimmerman, E D; Antoniou, N; Majka, Z; Dumarchez, J; Naskret, M; Ivashkin, A; Tsenov, R V; Koziel, M G; Schmidt, K J; Melkumov, G; Popov, B; Panagiotou, A; Richter-was, E M; Morgala, S J; Paolone, V; Damyanova, A; Gazdzicki, M; Unger, M T; Wilczek, A G; Stepaniak, J M; Seryakov, A; Susa, T; Staszel, P P; Brzychczyk, J; Maksiak, B; Tefelski, D B

2007-01-01

The NA61/SHINE (SHINE = SPS Heavy Ion and Neutrino Experiment) experiment is a large acceptance hadron spectrometer at the CERN SPS for the study of the hadronic final states produced in interactions of various beam particles (pions, protons, C, S and In) with a variety of fixed targets at the SPS energies. The main components of the current detector were constructed and used by the NA49 experiment. The physics program of NA61/SHINE consists of three main subjects. In the first stage of data taking (2007-2009) measurements of hadron production in hadron-nucleus interactions needed for neutrino (T2K) and cosmic-ray (Pierre Auger and KASCADE) experiments will be performed. In the second stage (2009-2011) hadron production in proton-proton and proton-nucleus interactions needed as reference data for a better understanding of nucleus-nucleus reactions will be studied. In the third stage (2009-2013) energy dependence of hadron production properties will be measured in nucleus-nucleus collisions as well as in p+p a...

Differences Between a Single- and a Double-Folding Nucleus-^{9}Be Optical Potential

Science.gov (United States)

Bonaccorso, A.; Carstoiu, F.; Charity, R. J.; Kumar, R.; Salvioni, G.

2016-05-01

We have recently constructed two very successful n-^9Be optical potentials (Bonaccorso and Charity in Phys Rev C89:024619, 2014). One by the Dispersive Optical Model (DOM) method and the other (AB) fully phenomenological. The two potentials have strong surface terms in common for both the real and the imaginary parts. This feature makes them particularly suitable to build a single-folded (light-) nucleus-^9Be optical potential by using ab-initio projectile densities such as those obtained with the VMC method (Wiringa http://www.phy.anl.gov/theory/research/density/). On the other hand, a VMC density together with experimental nucleon-nucleon cross-sections can be used also to obtain a neutron and/or proton-^9Be imaginary folding potential. We will use here an ab-initio VMC density (Wiringa http://www.phy.anl.gov/theory/research/density/) to obtain both a n-^9Be single-folded potential and a nucleus-nucleus double-folded potential. In this work we report on the cases of ^8B, ^8Li and ^8C projectiles. Our approach could be the basis for a systematic study of optical potentials for light exotic nuclei scattering on such light targets. Some of the projectiles studied are cores of other exotic nuclei for which neutron knockout has been used to extract spectroscopic information. For those cases, our study will serve to make a quantitative assessment of the core-target part of the reaction description, in particular its localization.

Transverse energy distribution, charged particle multiplicities and spectra in 16O-nucleus collisions

International Nuclear Information System (INIS)

Sunier, J.W.

1987-01-01

The HELIOS (High Energy Lepton and Ion Spectrometer) experiment, installed at the CERN Super Proton Synchrotron, proposes to examine in details the physical properties of a state of high energy created in nuclei by ultra-relativistic nucleus-nucleus collisions. It is generally believed that, at high densities or temperatures, a phase transition to a plasma of quark and gluons will occur. The dynamic of the expansion of such a plasma and its subsequent condensation into a hadron gas should markedly affect the composition and momentum distribution of the emerging particles and photons. The HELIOS experimental setup therefore combines 4π calorimetric coverage with measurements of inclusive particle spectra, two particle correlations, low and high mass lepton pairs and photons. The emphasis is placed on transverse energy flow (E/sub T/) measurements with good energy resolution, and the ability to trigger the acquisition of data in a variety of E/sub T/ ranges, thereby selecting the impact parameter or the violence of the collisions. This short note presents HELIOS results, for the most part still preliminary, on 16 O-nucleus collisions at the incident energies of 60 and 200 GeV per nucleon. The E/sub T/ distributions from Al, Ag and W targets are discussed and compared to the associated charged particle multiplicities from W. Charged particle and (converted) photon spectra measured with the external magnetic spectrometer are compared for 16 O + W and p + W collisions at 200 GeV per nucleon. 5 refs., 7 figs

Nucleonic gauging

International Nuclear Information System (INIS)

Bond, A.

1977-01-01

The present position of nucleonic techniques for process measurements, is considered from the technical and cost viewpoints. Systems considered include level, density, thickness (including coating thickness), moisture, and sulphur in hydrocarbons gauges and also belt weighers. The advantages of such systems are discussed and the cost-benefit position considered. The combination of nucleonic measuring equipment with a microcomputer is examined. (U.K.)

Pion photoproduction in nucleons at low energies

International Nuclear Information System (INIS)

Carvalho, F.A.B.R. de.

1983-01-01

A new semiphenomenological analysis of the multipoles for pion photoproduction from nucleons, in the region of the first π-N resonance is presented. Through an energy dependent model, multipoles with isospin 1/2 and 3/2 and total angular momentum J [pt

A measurement of the A-dependence of the J/PSI cross section by comparing data on hydrogen and tungsten targets at 39.5 GeV/c

International Nuclear Information System (INIS)

Corden, M.J.; Dowell, J.D.; Garvey, J.; Homer, R.J.; Jobes, M.; Kenyon, I.R.; McMahon, T.J.; Owen, R.C.; Sumorok, K.C.T.; Vallance, R.J.

1982-01-01

J/PSI production on hydrogen and tungsten targets has been compared at 39.5 GeV/c and the variation of the A-dependence of the J/PSI cross section as a function of psub(t) 2 and xsub(F) has been measured. The A-dependence parameter, α, rises with increasing p 2 2 and falls with increasing xsub(F). Both effects are shown not to be due to the Fermi motion of nucleons in the tungsten nucleus. (orig.)

Problem of construction of the operator of the electromagnetic current of a nucleus

International Nuclear Information System (INIS)

Korchin, A.Y.; Shebeko, A.V.

1984-01-01

The idea of R. G. Sachs [Phys. Rev. 74, 433 (1948)] in the phenomenological theory of exchange currents in nuclei is developed to obtain an expression for the Hamiltonian of a nucleus. An expression is obtained for the current which has the same isospin structure as the pion and seagull currents in the theory of meson exchange currents. Sachs' result follows for the case of point nucleons

mu. -nucleon atoms

Energy Technology Data Exchange (ETDEWEB)

Dobretsov, Yu; Dolgoshein, B; Kirillov-Ugryumov, V

1980-12-01

The properties and formation are described of ..mu..-nucleon atoms, the Larmor method of muon spin precession is discussed and the experimental confirmation of the existence of ..mu..-nucleon atoms is shown. The prospects of their use are indicated.

Detector development and background estimation for the observation of Coherent Neutrino Nucleus Scattering (CNNS)

Energy Technology Data Exchange (ETDEWEB)

Guetlein, Achim; Ciemniak, Christian; Feilitzsch, Franz von; Lanfranchi, Jean-Come; Oberauer, Lothar; Potzel, Walter; Roth, Sabine; Schoenert, Stefan; Sivers, Moritz von; Strauss, Raimund; Wawoczny, Stefan; Willers, Michael; Zoeller, Andreas [Technische Universitaet Muenchen, Physik-Department, E15 (Germany)

2012-07-01

The Coherent Neutrino Nucleus Scattering (CNNS) is a neutral current process of the weak interaction and is thus flavor independent. A low-energetic neutrino scatters off a target nucleus. For low transferred momenta the wavelength of the transferred Z{sup 0} boson is comparable to the diameter of the target nucleus. Thus, the neutrino interacts with all nucleons coherently and the cross section for the CNNS is enhanced. To observe CNNS for the first time we are developing cryogenic detectors with a target mass of about 10 g each and an energy threshold of less than 0.5 keV. The current status of this development is presented as well as the estimated background for an experiment in the vicinity of a nuclear power reactor as a strong neutrino source.

Isospin splitting of nucleon effective mass and symmetry energy in isotopic nuclear reactions

Science.gov (United States)

Guo, Ya-Fei; Chen, Peng-Hui; Niu, Fei; Zhang, Hong-Fei; Jin, Gen-Ming; Feng, Zhao-Qing

2017-10-01

Within an isospin and momentum dependent transport model, the dynamics of isospin particles (nucleons and light clusters) in Fermi-energy heavy-ion collisions are investigated for constraining the isospin splitting of nucleon effective mass and the symmetry energy at subsaturation densities. The impacts of the isoscalar and isovector parts of the momentum dependent interaction on the emissions of isospin particles are explored, i.e., the mass splittings of and (). The single and double neutron to proton ratios of free nucleons and light particles are thoroughly investigated in the isotopic nuclear reactions of 112Sn+112Sn and 124Sn+124Sn at incident energies of 50 and 120 MeV/nucleon, respectively. It is found that both the effective mass splitting and symmetry energy impact the kinetic energy spectra of the single ratios, in particular at the high energy tail (larger than 20 MeV). The isospin splitting of nucleon effective mass slightly impacts the double ratio spectra at the energy of 50 MeV/nucleon. A soft symmetry energy with stiffness coefficient of γ s=0.5 is constrained from the experimental data with the Fermi-energy heavy-ion collisions. Supported by Major State Basic Research Development Program in China (2014CB845405, 2015CB856903), National Natural Science Foundation of China (11722546, 11675226, 11675066, U1332207) and Youth Innovation Promotion Association of Chinese Academy of Sciences

Meson cloud in the nucleon and its consequences in various phenomena

Energy Technology Data Exchange (ETDEWEB)

Szczurek, A. [The H. Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)

1997-06-01

Consequences of the meson cloud in the nucleon and search for its evidences in various phenomena in both soft and hard processes were discussed. The cut-off parameters of the form factors (FF) for meson-baryon vertices are determined from high-energy particle production data. An universal cut-off parameter for processes involving octet baryons has been found. Relativistic calculations of the effects of the pion cloud on the electromagnetic properties of the nucleon are presented. Light-cone formalism was used to construct the nucleon wave function. The elastic electromagnetic nucleon FF G{sup p,n}{sub E}(Q{sup 2}) and G{sup p,n}{sub M} (Q{sup 2}) are computed in terms of matrix elements of current operator and the nucleon wave function. The Q{sup 2}-dependence of contributions to the nucleon FF from the various sectors of the model space is calculated. The observed deviations from FF scaling and dipole parameterization is discussed. A set of formulae for longitudinal momentum distribution functions (splitting functions) of mesons in the nucleon has been determined. The value of the Gottfried Sum Rule obtained from model (S{sub G}=0.224) agrees with that obtained by the NMC. The calculated axial coupling constants for semileptonic decays of the octet baryons agree with the experimental data. Enhanced production of events at large x in comparison to standard sets of quark distributions with rather mild Q{sup 2}-dependence was predicted. The semi-inclusive cross section for producing slow protons in charged current deep inelastic (anti-)neutrino scattering nucleons is calculated as a function of the x and the proton momentum. The possible consequences of the meson cloud in the nucleon for the production of the W and Z bosons in hadron-hadron collisions were discussed. A good description of the total W and Z production cross sections measured in the proton-antiproton collisions as well as the lepton asymmetry have been obtained. The model predicts an enhancement of the

Inequalities and bounds for nucleon-nucleon scattering

International Nuclear Information System (INIS)

Ramandurai, K.S.

1979-08-01

The objective of this work is to derive model-independent inequalities and bounds for nucleon-nucleon elastic scattering amplitudes based on well-established theoretical principles and symmetries. Two classes of methods are used: algebraic and variational. In the algebraic part, the author derives inequalities and bounds for NN amplitudes and observables using their mutual relations and x symmetries. In the variational part, he employs Lagrange's method of undetermined multipliers to evaluate the bounds. He tests the predictions of a sample of proposed phase shifts at three different energies using the results obtained

Weak interaction and nucleus: the relationship keeps on; Interaction faible et noyau: l'histoire continue

Energy Technology Data Exchange (ETDEWEB)

Martino, J [Subatech, Ecole des Mines de Nantes, 44 - Nantes (France); Frere, J M; Naviliat-Cuncic, O; Volpe, C; Marteau, J; Lhuillier, D; Vignaud, D; Legac, R; Marteau, J; Legac, R

2003-07-01

This document gathers the lectures made at the Joliot-Curie international summer school in 2003 whose theme, that year, was the relationship between weak interaction and nucleus. There were 8 contributions whose titles are: 1) before the standard model: from beta decay to neutral currents; 2) the electro-weak theory and beyond; 3) testing of the standard model at low energies; 4) description of weak processes in nuclei; 5) 20.000 tonnes underground, an approach to the neutrino-nucleus interaction; 6) parity violation from atom to nucleon; 7) how neutrinos got their masses; and 8) CP symmetry.

μ-nucleon atoms

International Nuclear Information System (INIS)

Dobretsov, Yu.; Dolgoshejn, B.; Kirillov-Ugryumov, V.

1980-01-01

The properties and formation are described of μ-nucleon atoms, the Larmor method of muon spin precession is discussed and the experimental confirmation of the existence of μ-nucleon atoms is shown. The prospects of their use are indicated. (J.P.)

Importance of momentum dependence interaction on the isospin effects of two-body dissipation

International Nuclear Information System (INIS)

Yang Yanfang; Guo Wenjun; Zhao Qiang; Liu Jianye; Zuo Wei

2002-01-01

The role of momentum dependence equation of state on the nuclear stopping for the isospin dependence and the isospin independence of in-medium nucleon-nucleon cross section is studied by using the isospin dependence quantum molecular dynamics. The nuclear stopping depends strongly on the isospin dependence of in-medium nucleon-nucleon cross section and weakly on the isospin dependence of the mean field-symmetry potential from above the Fermi energy to about 150 MeV/u for the small impact parameters. A detail study indicates that the difference between the nuclear stopping for the isospin dependence and the isospin independence of in-medium nucleon-nucleon cross section depends sensitively on the momentum dependence interaction, namely, the difference between the nuclear stopping for the isospin dependence and the isospin independence of in-medium nucleon-nucleon cross section in the present of momentum dependence interaction is larger than that without the momentum dependence interaction (MDI) for the mass symmetry and mass asymmetry reaction systems, neutron-rich and neutron-poor reaction systems. Namely, MDI increases the sensitivity of the nuclear stopping on the isospin dependence nucleon-nucleon cross section. Therefore, the knowledge on the isospin dependence of in-medium nucleon-nucleon cross section can be extracted more accurately from nucleon stopping as a probe if the momentum dependence interaction is taken into account

Electromagnetic and axial-vector form factors of the quarks and nucleon

Science.gov (United States)

Dahiya, Harleen; Randhawa, Monika

2017-11-01

In light of the improved precision of the experimental measurements and enormous theoretical progress, the nucleon form factors have been evaluated with an aim to understand how the static properties and dynamical behavior of nucleons emerge from the theory of strong interactions between quarks. We have analyzed the vector and axial-vector nucleon form factors (GE,Mp,n(Q2) and GAp,n(Q2)) using the spin observables in the chiral constituent quark model (χCQM) which has made a significant contribution to the unraveling of the internal structure of the nucleon in the nonperturbative regime. We have also presented a comprehensive analysis of the flavor decomposition of the form factors (GEq(Q2), GMq(Q2) and GAq(Q2) for q = u,d,s) within the framework of χCQM with emphasis on the extraction of the strangeness form factors which are fundamental to determine the spin structure and test the chiral symmetry breaking effects in the nucleon. The Q2 dependence of the vector and axial-vector form factors of the nucleon has been studied using the conventional dipole form of parametrization. The results are in agreement with the available experimental data.

Multiparticle excitations in the {sup 149} Gd superdeformed nucleus. Signature of new C{sub 4} nucleus symmetry; Excitations multiparticules dans le noyau superdeforme {sup 149}Gd. Signature d`une symetrie nouvelle C{sub 4} du noyau

Energy Technology Data Exchange (ETDEWEB)

Theisen, C

1995-01-01

The use of 8 {pi} and EUROGAM phase I multi-detectors for the study of high spin states of {sup 149} Gd nucleus has revealed unexpected new phenomenons about the superdeformation in this nucleus. The new excited bands confirm the omnipresence of twin bands phenomenon. A new multi-particle excitation (two protons and one neutron) has been discovered. Thanks to the second generation EUROGAM detector, unexpected discoveries such as C{sub 4} symmetry, level interactions, complete backbending were obtained for the second potential well. The knowledge of interacting levels gives informations about the nucleon-nucleon residual interaction and could allow the determination of SD bands excitation energy. The complex processing and analysis of high multiplicity events has led to the development of new computing tools. An automatic band research program has been written for the discovery of new excited bands, and an exact method for the elimination of uncorrected events has been developed. The improvements of multi-detector performances should allow the discovery of more exceptional phenomenons and new anomalies in the SD bands. (J.S.). 222 refs., 86 figs., 38 tabs.

Nucleon-gold collisions at 200 A GeV using tagged d + Au interactions in the PHOBOS detector

Science.gov (United States)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Sarin, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.; Zhang, J.; Phobos Collaboration

2015-09-01

Forward calorimetry in the PHOBOS detector has been used to study charged hadron production in d +Au , p +Au , and n +Au collisions at √{sN N}=200 GeV . The forward proton calorimeter detectors are described and a procedure for determining collision centrality with these detectors is detailed. The deposition of energy by deuteron spectator nucleons in the forward calorimeters is used to identify p +Au and n +Au collisions in the data. A weighted combination of the yield of p +Au and n +Au is constructed to build a reference for Au +Au collisions that better matches the isospin composition of the gold nucleus. The pT and centrality dependence of the yield of this improved reference system is found to match that of d +Au . The shape of the charged-particle transverse momentum distribution is observed to extrapolate smoothly from p +p ¯ to central d +Au as a function of the charged-particle pseudorapidity density. The asymmetry of positively and negatively charged hadron production in p +Au is compared to that of n +Au . No significant asymmetry is observed at midrapidity. These studies augment recent results from experiments at the CERN Large Hadron Collider and BNL Relativistic Heavy Ion Collider facilities to give a more complete description of particle production in p +A and d +A collisions, essential for the understanding the medium produced in high-energy nucleus-nucleus collisions.

Double polarized neutron-proton scattering and nucleon-nucleon tensor force: An alternative analysis

International Nuclear Information System (INIS)

Tornow, W.; Gould, C.R.; Haase, D.G.; Walston, J.R.; Raichle, B.W.

2002-01-01

Previous neutron-proton total cross-section difference measurements Δσ L and Δσ T between E n =7.43 and 17.1 MeV have been analyzed in a new way that reduces experimental systematic uncertainties. The results obtained for the 3 S 1 - 3 D 1 mixing parameter ε 1 are very similar to the published values, substantiating the previous conclusion that the nucleon-nucleon tensor force at low energies is stronger than predicted by the Nijmegen partial-wave analysis and, therefore, by all the recent high-precision nucleon-nucleon potential models as well

Sea quarks contribution to the nucleon magnetic moment and charge radius at the physical point

Science.gov (United States)

Sufian, Raza Sabbir; Yang, Yi-Bo; Liang, Jian; Draper, Terrence; Liu, Keh-Fei; χ QCD Collaboration

2017-12-01

We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form factors. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We adopt a model-independent extrapolation of the nucleon magnetic moment and the charge radius. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light and strange disconnected-sea quarks contribution to the nucleon magnetic moment is μM(DI )=-0.022 (11 )(09 ) μN and to the nucleon mean square charge radius is ⟨r2⟩E(DI ) =-0.019 (05 )(05 ) fm2 which is about 1 /3 of the difference between the ⟨rp2⟩E of electron-proton scattering and that of a muonic atom and so cannot be ignored in obtaining the proton charge radius in the lattice QCD calculation. The most important outcome of this lattice QCD calculation is that while the combined light-sea and strange quarks contribution to the nucleon magnetic moment is small at about 1%, a negative 2.5(9)% contribution to the proton mean square charge radius and a relatively larger positive 16.3(6.1)% contribution to the neutron mean square charge radius come from the sea quarks in the nucleon. For the first time, by performing global fits, we also give predictions of the light and strange disconnected-sea quarks contributions to the nucleon electric and magnetic form factors at the physical point and in the continuum and infinite volume limits in the momentum transfer range of 0 ≤Q2≤0.5 GeV2 .