Physical Review CPub Date : 2011-04-15DOI: 10.1103/PhysRevC.83.044320
H. K. Toft, A. Larsen, A. Bürger, M. Guttormsen, A. Görgen, H. Nyhus, T. Renstrøm, S. Siem, G. Tveten, A. Voinov
{"title":"Evolution of the pygmy dipole resonance in Sn isotopes","authors":"H. K. Toft, A. Larsen, A. Bürger, M. Guttormsen, A. Görgen, H. Nyhus, T. Renstrøm, S. Siem, G. Tveten, A. Voinov","doi":"10.1103/PhysRevC.83.044320","DOIUrl":"https://doi.org/10.1103/PhysRevC.83.044320","url":null,"abstract":"Nuclear level density and {gamma}-ray strength functions of {sup 121,122}Sn below the neutron separation energy are extracted with the Oslo method using the ({sup 3}He,{sup 3}He{sup '{gamma}}) and ({sup 3}He,{alpha}{gamma}) reactions. The level densities of {sup 121,122}Sn display steplike structures, interpreted as signatures of neutron pair breaking. An enhancement in both strength functions, compared to standard models for radiative strength, is observed in our measurements for E{sub {gamma}} > or approx. 5.2 MeV. This enhancement is compatible with pygmy resonances centered at {approx_equal}8.4(1) and {approx_equal}8.6(2) MeV, respectively, and with integrated strengths corresponding to {approx_equal}1.8{sub -5}{sup +1}% of the classical Thomas-Reiche-Kuhn sum rule. Similar resonances were also seen in {sup 116-119}Sn. Experimental neutron-capture cross reactions are well reproduced by our pygmy resonance predictions, while standard strength models are less successful. The evolution as a function of neutron number of the pygmy resonance in {sup 116-122}Sn is described as a clear increase of centroid energy from 8.0(1) to 8.6(2) MeV, but with no observable difference in integrated strengths.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"58 1","pages":"044320"},"PeriodicalIF":3.1,"publicationDate":"2011-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85775331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review CPub Date : 2010-07-22DOI: 10.1103/PhysRevC.83.042201
D. Dutta, Jen-Chieh Peng, I. Cloët, D. Gaskell
{"title":"Pion-induced Drell-Yan processes and the flavor-dependent EMC effect","authors":"D. Dutta, Jen-Chieh Peng, I. Cloët, D. Gaskell","doi":"10.1103/PhysRevC.83.042201","DOIUrl":"https://doi.org/10.1103/PhysRevC.83.042201","url":null,"abstract":"Pion-induced Drell-Yan processes are proposed as a potential tool to measure the flavor dependence of the EMC effect, that is, the flavor-dependent modification of quark distributions in the nuclear medium. Existing pionic Drell-Yan data are compared with calculations using a recent model for nuclear quark distributions that incorporates flavor-dependent nuclear effects. While no firm conclusions can yet be drawn, we demonstrate that existing Drell-Yan data seem to imply a flavor dependence of the EMC effect. We highlight how pion-induced Drell-Yan experiments on nuclear targets can access important new aspects of the EMC effect, not probed in deep inelastic scattering, and will therefore provide very stringent constrains for models of nuclear quark distributions. Predictions for possible future pion-induced Drell-Yan experiments are also presented.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"30 1","pages":"042201"},"PeriodicalIF":3.1,"publicationDate":"2010-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90043904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review CPub Date : 2009-12-03DOI: 10.1103/PhysRevC.81.044901
S. C. B. Abelev, E. al.
{"title":"Observation of pi{sup +}pi{sup -}pi{sup +}pi{sup -} photoproduction in ultraperipheral heavy-ion collisions at sq root(s{sub NN})=200 GeV at the STAR detector","authors":"S. C. B. Abelev, E. al.","doi":"10.1103/PhysRevC.81.044901","DOIUrl":"https://doi.org/10.1103/PhysRevC.81.044901","url":null,"abstract":"We present a measurement of pi{sup +}pi{sup -}pi{sup +}pi{sup -} photonuclear production in ultraperipheral Au-Au collisions at sq root(s{sub N{sub N}})=200 GeV from the STAR experiment. The pi{sup +}pi{sup -}pi{sup +}pi{sup -} final states are observed at low transverse momentum and are accompanied by mutual nuclear excitation of the beam particles. The strong enhancement of the production cross section at low transverse momentum is consistent with coherent photoproduction. The pi{sup +}pi{sup -}pi{sup +}pi{sup -} invariant mass spectrum of the coherent events exhibits a broad peak around 1540+-40 MeV/c{sup 2} with a width of 570+-60 MeV/c{sup 2}, in agreement with the photoproduction data for the rho{sup 0}(1700). We do not observe a corresponding peak in the pi{sup +}pi{sup -} final state and measure an upper limit for the ratio of the branching fractions of the rho{sup 0}(1700) to pi{sup +}pi{sup -} and pi{sup +}pi{sup -}pi{sup +}pi{sup -} of 2.5% at 90% confidence level. The ratio of rho{sup 0}(1700) and rho{sup 0}(770) coherent production cross sections is measured to be 13.4+-0.8{sub stat.}+-4.4{sub syst.}%.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"61 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2009-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86630699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Large Q 2 electrodisintegration of the deuteron in the virtual nucleon approximation","authors":"M. Sargsian","doi":"10.1063/1.3647152","DOIUrl":"https://doi.org/10.1063/1.3647152","url":null,"abstract":"The two-body breakup of the deuteron is studied at high-Q{sup 2} kinematics, with the main motivation to probe the deuteron at small internucleon distances. Such studies are associated with the probing of the high-momentum component of the deuteron wave function. For this, two main theoretical issues have been addressed: electromagnetic interaction of the virtual photon with the bound nucleon and the strong interaction of produced baryons in the final state of the breakup reaction. Within virtual nucleon approximation we developed a new prescription to account for the bound nucleon effects in electromagnetic interaction. The final-state interaction at high-Q{sup 2} kinematics is calculated within the generalized eikonal approximation (GEA). We studied the uncertainties involved in the calculation and performed comparisons with the first experimental data on deuteron electrodisintegration at large Q{sup 2}. We demonstrate that the experimental data confirm the GEA's early prediction that the rescattering is maximal at approx70 deg. of recoil nucleon production relative to the momentum of the virtual photon. Comparisons also show that the forward recoil nucleon angles are best suited for studies of the electromagnetic interaction of bound nucleons and the high-momentum structure of the deuteron. Backward recoil angle kinematics show sizable effects owing to themore » DELTA-isobar contribution. The latter indicates the importance of further development of the GEA to account for the inelastic transitions in the intermediate state of the electrodisintegration reactions.« less","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"61 1","pages":"014612"},"PeriodicalIF":3.1,"publicationDate":"2009-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77226300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review CPub Date : 2007-04-05DOI: 10.1103/PhysRevC.76.014312
T. Lesinski, M. Bender, K. Bennaceur, T. Duguet, Jean-Arcady Meyer
{"title":"The tensor part of the Skyrme energy density functional. I. Spherical nuclei","authors":"T. Lesinski, M. Bender, K. Bennaceur, T. Duguet, Jean-Arcady Meyer","doi":"10.1103/PhysRevC.76.014312","DOIUrl":"https://doi.org/10.1103/PhysRevC.76.014312","url":null,"abstract":"We perform a systematic study of the impact of the J^2 tensor term in the Skyrme energy functional on properties of spherical nuclei. In the Skyrme energy functional, the tensor terms originate both from zero-range central and tensor forces. We build a set of 36 parameterizations, which covers a wide range of the parameter space of the isoscalar and isovector tensor term coupling constants, with a fit protocol very similar to that of the successful SLy parameterizations. We analyze the impact of the tensor terms on a large variety of observables in spherical mean-field calculations, such as the spin-orbit splittings and single-particle spectra of doubly-magic nuclei, the evolution of spin-orbit splittings along chains of semi-magic nuclei, mass residuals of spherical nuclei, and known anomalies of charge radii. Our main conclusion is that the currently used central and spin-orbit parts of the Skyrme energy density functional are not flexible enough to allow for the presence of large tensor terms.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"81 1","pages":"014312"},"PeriodicalIF":3.1,"publicationDate":"2007-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80984078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review CPub Date : 2006-05-01DOI: 10.1088/0954-3899/32/5/B03
G. Ramachandran, Y. Y. Oo, S. Shilpashree
{"title":"Deuteron photodisintegration with polarized photons at astrophysical energies","authors":"G. Ramachandran, Y. Y. Oo, S. Shilpashree","doi":"10.1088/0954-3899/32/5/B03","DOIUrl":"https://doi.org/10.1088/0954-3899/32/5/B03","url":null,"abstract":"Following precise experimental studies at the Duke Free-Electron Laser Laboratory, we discuss the photodisintegration of deuterons with 100% linearly polarized photons using a model independent theoretical approach taking together M1 and E1 amplitudes simultaneously. The isoscalar M1{sub s} contribution is also taken exactly into account. From the existing experimental measurement on doubly polarized thermal neutron capture, it is seen that the isoscalar M1{sub s} contribution could be of the same order of magnitude as the experimentally measured cross sections at energies relevant to Big Bang Nucleosynthesis (BBN). Therefore appropriate measurements on deuteron photodisintegration are suggested to empirically determine the M1{sub s} contribution at astrophysical energies.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"35 1","pages":"052801"},"PeriodicalIF":3.1,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89438470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review CPub Date : 2005-07-15DOI: 10.1103/PhysRevC.72.045501 10.1103/PhysRevC.83.019901
S. Sjue
{"title":"Polarized neutron β-decay: Proton asymmetry and recoil-order currents","authors":"S. Sjue","doi":"10.1103/PhysRevC.72.045501 10.1103/PhysRevC.83.019901","DOIUrl":"https://doi.org/10.1103/PhysRevC.72.045501 10.1103/PhysRevC.83.019901","url":null,"abstract":"We present an analytic, recoil-order calculation of the proton asymmetry from polarized neutron ensuremath{beta}-decay. The differential decay rate in terms of electron energy and proton direction follows, parametrized in terms of the most general Lorentz-invariant hadron current coupled to a left-handed lepton current. Implications for experimental efforts to measure recoil-order currents are discussed.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"17 1","pages":"045501"},"PeriodicalIF":3.1,"publicationDate":"2005-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81752727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review CPub Date : 2004-04-15DOI: 10.1103/PhysRevC.70.044901
J. Adams, M. Aggarwal, Z. Ahammed, J. Amonett, B. Anderson, D. Arkhipkin, G. S. Averichev, Y. Bai, J. Balewski, O. Barannikova, L. Barnby, J. Baudot, S. Bekele, V. Belaga, R. Bellwied, J. Berger, B. I. Bezverkhny, S. Bharadwaj, V. Bhatia, H. Bichsel, A. Billmeier, L. Bland, C. Blyth, B. Bonner, M. Botje, A. Boucham, A. Brandin, A. Bravar, M. Bysterský, R. Cadman, X. Cai, H. Caines, M. Sanchez, J. Carroll, J. Castillo, D. Cebra, P. Chaloupka, S. Chattopdhyay, H. Chen, Y. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, J. Coffin, T. Cormier, J. Cramer, H. Crawford, D. Das, S. Das, M. M. Moura, A. Derevschikov, L. Didenko, T. Dietel, W. Dong, X. Dong, J. Draper, F. Du, A. Dubey, V. Dunin, J. Dunlop, M. Mazumdar, V. Eckardt, W. Edwards, L. Efimov, V. Emelianov, J. Engelage, G. Eppley, B. Erazmus, M. Estienne, P. Fachini, J. Faivre, R. Fatémi, J. Fedorišin, K. Filimonov, P. Filip, E. Finch, V. Fine, Y. Fisyak, K. J. Foley, K. Fomenko, J. Fu, C. Gagliardi, J. Gans, M. Ganti, L. Gaudichet, F. Geurts, V. G
{"title":"Centrality and pseudorapidity dependence of charged hadron production at intermediate p{sub t} in Au+Au collisions at {radical}s{sub NN} = 130 GeV","authors":"J. Adams, M. Aggarwal, Z. Ahammed, J. Amonett, B. Anderson, D. Arkhipkin, G. S. Averichev, Y. Bai, J. Balewski, O. Barannikova, L. Barnby, J. Baudot, S. Bekele, V. Belaga, R. Bellwied, J. Berger, B. I. Bezverkhny, S. Bharadwaj, V. Bhatia, H. Bichsel, A. Billmeier, L. Bland, C. Blyth, B. Bonner, M. Botje, A. Boucham, A. Brandin, A. Bravar, M. Bysterský, R. Cadman, X. Cai, H. Caines, M. Sanchez, J. Carroll, J. Castillo, D. Cebra, P. Chaloupka, S. Chattopdhyay, H. Chen, Y. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, J. Coffin, T. Cormier, J. Cramer, H. Crawford, D. Das, S. Das, M. M. Moura, A. Derevschikov, L. Didenko, T. Dietel, W. Dong, X. Dong, J. Draper, F. Du, A. Dubey, V. Dunin, J. Dunlop, M. Mazumdar, V. Eckardt, W. Edwards, L. Efimov, V. Emelianov, J. Engelage, G. Eppley, B. Erazmus, M. Estienne, P. Fachini, J. Faivre, R. Fatémi, J. Fedorišin, K. Filimonov, P. Filip, E. Finch, V. Fine, Y. Fisyak, K. J. Foley, K. Fomenko, J. Fu, C. Gagliardi, J. Gans, M. Ganti, L. Gaudichet, F. Geurts, V. G","doi":"10.1103/PhysRevC.70.044901","DOIUrl":"https://doi.org/10.1103/PhysRevC.70.044901","url":null,"abstract":"We present STAR measurements of charged hadron production as a function of centrality in Au+Au collisions at {radical}(s{sub NN})=130 GeV. The measurements cover a phase space region of 0.2 p{sub T}{sup cut}, and studied the results in the framework of participant and binary scaling. No clear evidence is observed for participant scaling of charged hadron yield in the measured p{sub T} region. The relative importance of hard scattering processes is investigated through binary scaling fraction of particle production.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"36 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2004-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73860114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review CPub Date : 2004-03-11DOI: 10.1103/PhysRevC.69.047301
T. Nikšić, D. Vretenar, G. Lalazissis, P. Ring
{"title":"Ground-state properties of rare-earth nuclei in the relativistic Hartree-Bogoliubov model with density-dependent meson-nucleon couplings","authors":"T. Nikšić, D. Vretenar, G. Lalazissis, P. Ring","doi":"10.1103/PhysRevC.69.047301","DOIUrl":"https://doi.org/10.1103/PhysRevC.69.047301","url":null,"abstract":"The relativistic mean-field effective interaction with density-dependent meson-nucleon couplings DD-ME1 is tested in the calculation of deformed nuclei. Ground-state properties of six isotopic chains $(60ensuremath{leqslant}Zensuremath{leqslant}70)$ in the region of rare-earth nuclei are calculated by using the relativistic Hartree-Bogoliubov (RHB) model with the DD-ME1 mean-field interaction, and with the Gogny D1S force for the pairing interaction. Results of fully self-consistent RHB calculations for the total binding energies, charge isotope shifts, and quadrupole deformation parameters are compared with the available empirical data.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"45 1","pages":"047301"},"PeriodicalIF":3.1,"publicationDate":"2004-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82703653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review CPub Date : 2002-08-06DOI: 10.1103/PhysRevC.66.041601
L. Moretto, J. B. Elliott, L. Phair, G. Wozniak
{"title":"Negative heat capacities and first order phase transitions in nuclei","authors":"L. Moretto, J. B. Elliott, L. Phair, G. Wozniak","doi":"10.1103/PhysRevC.66.041601","DOIUrl":"https://doi.org/10.1103/PhysRevC.66.041601","url":null,"abstract":"Anomalous negative heat capacities have been claimed as indicators of first-order phase transitions in finite systems in general, and for nuclear systems in particular. A thermodynamic approach allowing for all Q-value terms is used to evaluate heat capacities in finite van der Waals fluids and finite lattice systems in the coexistence region. Fictitious large effects and negative heat capacities are observed in lattice systems when periodic boundary conditions are introduced. Small anomalous effects are predicted for small drops and for finite lattice systems. A straightforward application of the analysis to nuclei shows that negative heat capacities cannot be observed for $Ag60.$","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":"68 1","pages":"041601"},"PeriodicalIF":3.1,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79640954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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