javier roca maza – curriculum vitaejroca/doc/cv/cv-eng-140110.pdf · 2014. 1. 10. · javierroca...

Javier Roca MazaCurriculum Vitae

Personal InformationFamily name Roca MazaGiven name Javier

Address Via Pacini 34, I-20131 MilanoCell Phone (+39) 338 117 00 94

e-mail [email protected] of birth 3rd of June 1978Place of birth Barcelona

Citizenship SpanishPassportnumber

AAC464902

Expirationdate

23rd of September 2020

Present positionPostDoc - researcher

Institution University of MilanPhysics Department

Office Via Celoria 16, I-20133 MilanoSezione Fisica del Nucleo, LITA building1st floor, room number A/1/C1

e-mail [email protected] (+39) 02 503 17 225

Fax (+39) 02 503 17 487Website www.mi.infn.it/~jroca/

Via Pacini 34 – Milano, Italy 20131H (+39) 338 117 00 94 • T (+39) 02 503 17 225

B [email protected] • Í www.mi.infn.it/ jroca/ 1/16

mailto:[email protected]:[email protected]://www.mi.infn.it/~jroca/mailto:[email protected]://www.mi.infn.it/~jroca/

Education2009 Course on Pedagogical Aptitude

Institution University of Barcelona, SpainPhD Thesis

2005–2010 University of Barcelona, SpainTitle Isospin asymmetry in stable and exotic nuclei

Supervisors Prof. Xavier Viñas i Gausí and Prof. Mario Centelles i AixalàGrade “Excel.lent Cum Laude”

Description Physical properties of nuclei, such as the mass, neutron and proton distributions,collective excitations, fission properties, etc. are influenced by the isospin dependenceof the nuclear strong interaction. The symmetry energy and its density dependenceaccount for the effects observed in nuclei with proton-neutron differences. Therefore,the accurate characterization of this property entails profound consequences instudying the nucleus. It also impacts on diverse areas such as nuclear astrophysics andtests of the Standard Model via atomic parity violation. The experimental situationwill change considerably within the next years. The advent of new techniques tosynthesize and perform experiments with exotic nuclei will allow this change. Thissituation have motivated the studies presented along this Thesis where some aspectsof the isospin dependence of the nuclear force have been investigated. Our aimwas to understand the effects that such dependence produce on different nuclearobservables of both, stable and exotic nuclei.

Stage From September to December 2007 at the Physics Department of the Florida StateUniversity. Collaboration project with Prof. Jorge Piekarewicz.

Advanced Studies Diploma Thesis2005–2007 University of Barcelona, Spain

Title Cooling by approximation to a N2 thermal bathSupervisor Prof. Eduard Vives

Grade “Excel.lent”Description Hardware and software set up of a cooling system by approximation to a nitrogen

thermal bath. That is a fully automatic device which allow the measurement ofdifferent thermodynamical properties of the material under study as a function ofthe temperature. From room temperature to nearly 77 K.

2005–2007 University of Barcelona, SpainTitle ESEN−Elastic Scattering of Electrons by Nuclei

Supervisor Prof. Francesc SalvatGrade “Excel.lent”

Description Modification of the ELSEPA code for the calculation of elastic electron scatteringby stable and exotic nuclei and analysis of scattering observables with modernmicroscopic nuclear mean-field models.

Master Degree in Physics2000–2004 University of Barcelona, Spain



mailto:[email protected]://www.mi.infn.it/~jroca/

AverageGrade

“Notable”, 7.6 in a scale from 0 to 10

Experience2014–2018 Italian Qualification for Associate Professor in the area 02/A2–Theoretical physics

of fundamental interactions. Bibliometric indicators reported by the commission:

-the number of articles during the last 10 years normalized by the academic age was34-the number of citations during the last 10 years normalized by the academic agewas 59.6-the contemporary h index was 11

Reviewer2012–Present Referee of Physical Review C

ISSN 1089-490X (online), 0556-2813 (print)

2012–Present Nuclear Physics AISSN 0375-9474

Research2012–Present PostDoc position. Research Grant.

Institution University of Milan, Physics Department

2010–2012 PostDoc position. Fellowship for foreign researchers.Institution Istituto Nazionale di Fisica Nucleare (INFN), Milan section

2010 PostDoc position. Contract (6 months).Institution University of Barcelona. Physics Department.

Teaching2013–2014 Co-supervisor of Master Thesis.Institution University of Milan

Student Valentina CraveiaTitle Elastic properties and collective modes of a neutron star crust (to be confirmed).

2013 Co-supervisor of Bachelor Thesis.Institution University of Milan

Student Davide BasilicoTitle Magnetic field effects on the composition of a neutron star outer crust (Italian).



https://abilitazione.cineca.it/ministero.php/public/elencodomande/settore/02%252FA2/fascia/2http://dx.doi.org/10.1007/s11192-007-1722-zhttp://www.mi.infn.it/~jroca/doc/thesis/thesis-davide-basilico.pdfmailto:[email protected]://www.mi.infn.it/~jroca/

2010–2011 Co-supervisor of Master Thesis.Institution University of MilanStudent Giacomo Pozzi

Title A Microscopic Model for the Collective Response in Odd Nuclei.

2009 Teaching to the 2nd course of “ESO” (basic physics) during my Course on Peda-gogical Aptitude

Institution IES Les Corts, Barcelona, Spain

2008–2010 Teaching assistant for the course of Laboratori de Termodinàmica (Physics), Subjectof the degree in Physics

Institution University of Barcelona.

Awards2011 Special Mention in the Dissertation Award in Nuclear Physics (2009-2011) of the

Nuclear Physics Division of the European Physical Society.

Fellowships2012–2014 PostDoctoral type-A fellowship from the University of Milan

2010-2012 PostDoctoral fellowship for non-italian citizens in theoretical physics.

2006-2010 Training University Lecturers (FPU) studentship (2 years) and contract (2 years)from the Spanish government for the accomplishment of my PhD courses and thesis.

2005 Studentship from the Spanish Government for the collaboration with the Departa-ment d’Estructura i Constituent de la Matèria at the University of Barcelona.This collaboration was developed within the framework of the research project enti-tled: Static and Dynamic Properties of Correlated Bosonic and Fermionic Systems.

2000-2004 Studentship from the Spanish government (providing full support for the Universitytuition).

Computer skillsAdvanced OS: Linux, WindowsAdvanced Fortran77

LanguagesSpanish NativeCatalan Native



http://www.mi.infn.it/~jroca/doc/thesis/thesis-giacomo-pozzi.pdfmailto:[email protected]://www.mi.infn.it/~jroca/

English Fluent spoken and writtenItalian Fluent spoken and written

Bibliometric indicators of my publications2008 First publication academic age < 6 years

30 Total number of publications publications per year > 5{ In A-class journals: 18{ In conference proceedings: 11{ In book or chapter: 1

Source: Thompson & Reuters AuthorID: E-4541-2013{ Total citations: 348 { Citations per year > 55{ h index: 10 { Contemporary h: 11Source: Scopus (no data on 2013) AuthorID: 25641764000{ Total citations: 339 { Citations per year > 65{ h index: 9 { Contemporary h: 12Source: Google Schoolar Citations{ Total citations: 512 { Citations per year > 85{ h index: 11 { Contemporary h: 12

List of PublicationsP1 Impact of the symmetry energy on the outer crust of non-accreting neutron stars

Authors X.Roca-Maza and J.PiekarewiczJournal Phys. Rev. C 78 025807

Year 2008

P2 Nuclear symmetry energy probed by neutron skin thickness of nucleiAuthors M. Centelles, X. Roca-Maza, X. Viñas, M. WardaJournal Phys. Rev. Lett. 102 122502

Year 2009

P3 Neutron skin thickness in droplet model with surface width dependence: indicationsof softness of the nuclear symmetry energy

Authors M. Warda, X. Viñas, X. Roca-Maza, M. CentellesJournal Phys. Rev. C 80 024316

Year 2009

P4 Analysis of bulk and surface contributions in the neutron skin of nucleiVia Pacini 34 – Milano, Italy 20131

H (+39) 338 117 00 94 • T (+39) 02 503 17 225B [email protected] • Í www.mi.infn.it/ jroca/ 5/16

http://www.researcherid.com/rid/E-4541-2013http://www.scopus.com/authid/detail.url?authorId=25641764000http://scholar.google.com/citations?user=BdppmzsAAAAJ&hl=cahttp://dx.doi.org/10.1103/PhysRevC.78.025807http://dx.doi.org/10.1103/PhysRevLett.102.122502http://dx.doi.org/10.1103/PhysRevC.80.024316http://dx.doi.org/10.1103/PhysRevC.80.024316http://dx.doi.org/10.1103/PhysRevC.81.054309mailto:[email protected]://www.mi.infn.it/~jroca/

Authors M. Warda, X. Viñas, X. Roca-Maza, M. CentellesJournal Phys. Rev. C 81 054309

Year 2010

P5 Origin of the neutron skin thickness of 208Pb in nuclear mean-field modelsAuthors M. Centelles, X. Roca-Maza, X. Viñas, M. WardaJournal Phys. Rev. C 82 054314

Year 2010

P6 Theoretical study of elastic electron scattering off stable and exotic nucleiAuthors X.Roca-Maza,M. Centelles, F. Salvat, X, ViñasJournal Phys. Rev. C 78 044332

Year 2008

P7 Neutron skin of 208Pb, nuclear symmetry energy, and the parity radius experimentAuthors X. Roca-Maza, M. Centelles, X. Viñas, M. WardaJournal Phys. Rev. Lett. 106 252501

Year 2011

P8 Relativistic mean field interaction with density dependent meson-nucleon verticesbased on microscopical calculations

Authors X. Roca-Maza, X. Viñas, M. Centelles, P. Ring and P. SchuckJournal Phys. Rev. C 84 054309

Year 2011

P9 Influence of the symmetry energy on the giant monopole resonance of neutron-richnuclei

Authors M. Centelles, S.K. Patra, X. Roca-Maza, B.K. Sharma, P.D. Stevenson, X. ViñasJournal J. Phys. G 37 075107

Year 2010

P10 Garvey-Kelson Relations for Nuclear Charge RadiiAuthors J. Piekarewicz, M. Centelles, X. Roca-Maza, X. ViñasJournal Eur. Phys. J. A 46 379-386

Year 2010

P11 Low-lying dipole response: isospin character and collectivity in 68Ni, 132Sn and208Pb

Authors X. Roca-Maza, G. Pozzi, M. Brenna, K. Mizuyama and G. ColòVia Pacini 34 – Milano, Italy 20131

H (+39) 338 117 00 94 • T (+39) 02 503 17 225B [email protected] • Í www.mi.infn.it/ jroca/ 6/16

http://dx.doi.org/10.1103/PhysRevC.82.054314http://dx.doi.org/10.1103/PhysRevC.78.044332http://dx.doi.org/10.1103/PhysRevLett.106.252501http://dx.doi.org/10.1103/PhysRevC.84.054309http://dx.doi.org/10.1103/PhysRevC.84.054309http://dx.doi.org/10.1088/0954-3899/37/7/075107http://dx.doi.org/10.1088/0954-3899/37/7/075107http://dx.doi.org/10.1140/epja/i2010-11051-8http://dx.doi.org/10.1103/PhysRevC.85.024601http://dx.doi.org/10.1103/PhysRevC.85.024601mailto:[email protected]://www.mi.infn.it/~jroca/

Journal Phys. Rev. C 85 024601Year 2012

P12 Electric dipole polarizability and the neutron skinAuthors J. Piekarewicz, B. K. Agrawal, G. Colò, W. Nazarewicz, N. Paar, P.-G. Reinhard, X.

Roca-Maza and D. VretenarJournal Phys. Rev. C 85 041302(R)

Year 2012

P13 Second-order equation of state with the full Skyrme interaction: toward new effec-tive interactions for beyond-mean-field models

Authors K. Moghrabi, M. Grasso, X. Roca-Maza and G. ColòJournal Phys. Rev. C 85 044323

Year 2012

P14 Constraints on the symmetry energy and neutron skins from experiments and theoryAuthors M. B. Tsang, J. R. Stone, F. Camera, P. Danielewicz, S. Gandolfi, K. Hebeler, C. J.

Horowitz, Jenny Lee, W. G. Lynch, Z. Kohley, R. Lemmon, P. Möller, T. Murakami,S. Riordan, X. Roca-Maza, F. Sammarruca, A. W. Steiner, I. Vidaña, and S. J.Yennello


P15 A new Skyrme interaction with improved spin-isospin propertiesAuthors X.Roca-Maza, G. Colò and H. SagawaJournal Phys. Rev. C 86 031306(R)

Year 2012

P16 Localized form of Fock terms in nuclear covariant density functional theoryAuthors Haozhao Liang, Pengwei Zhao, Peter Ring, Xavier Roca-Maza, and Jie MengJournal Phys. Rev. C 86 021302(R)

Year 2012

P17 Electron scattering in isotonic chains as a probe of the proton shell structure ofunstable nuclei

Authors X. Roca-Maza, M. Centelles, F. Salvat, X. ViñasJournal Phys. Rev. C 87 014304

Year 2013



http://dx.doi.org/10.1103/PhysRevC.85.041302http://dx.doi.org/10.1103/PhysRevC.85.044323http://dx.doi.org/10.1103/PhysRevC.85.044323http://dx.doi.org/10.1103/PhysRevC.86.015803http://dx.doi.org/10.1103/PhysRevC.86.031306http://dx.doi.org/10.1103/PhysRevC.86.021302http://dx.doi.org/10.1103/PhysRevC.87.014304http://dx.doi.org/10.1103/PhysRevC.87.014304mailto:[email protected]://www.mi.infn.it/~jroca/

P18 Giant Quadrupole Resonances in 208Pb, the nuclear symmetry energy and the neu-tron skin thickness

Authors X. Roca-Maza, M. Brenna, B. K. Agrawal, P. F. Bortignon, G. Colò, Li-Gang Cao,N. Paar, and D. Vretenar


P19 Electric Dipole Polarizability in 208Pb: correlations suggested by the Droplet ModelAuthors X. Roca-Maza, M. Brenna, G. Colò, M. Centelles, X. Viñas, B. K. Agrawal, et al.Journal In preparation

Year 2013

P20 Constraints on the symmetry energy near normal density from atomic masses andneutron skins in heavy nuclei

Authors X. Roca-Maza, X. Viñas, M. Centelles, and M. WardaJournal Invited contribution to the European Physical Journal A, special volume on nuclear

symmetry energy, in preparation.Year 2013

P21 Influence of the single-particle structure on the nuclear surface and the neutron skinAuthors M. Warda, M. Centelles, X. Viñas, and X. Roca-MazaJournal In preparation

Year 2013

Conference Proceedings & Volume ContributionsC1 The Impact of the Nuclear Symmetry Energy on the Structure and Composition of

the Outer CrustAuthors X. Roca-Maza, T. Garía, M. Centelles and J. PiekarewiczChapter “Neutron Star Crust”. Nova Publishers. ISBN: 978-1-62081-960-9.

Year 2012

C2 Study of the neutron skin thickness of 208Pb in mean field modelsAuthors X. Roca-Maza, M. Centelles, X. Viñas, M. WardaJournal J. Phys. : Conf. Ser. 321 012052

Year 2011

C3 Nuclear symmetry energy and neutron skin thicknessAuthors M. Warda, M. Centelles, X. Viñas and X. Roca-Maza



http://dx.doi.org/10.1103/PhysRevC.87.034301http://dx.doi.org/10.1103/PhysRevC.87.034301http://inspirehep.net/record/927434http://inspirehep.net/record/927434http://dx.doi.org/10.1088/1742-6596/321/1/012052http://dx.doi.org/10.5506/APhysPolB.43.209mailto:[email protected]://www.mi.infn.it/~jroca/

Journal A. Phys. Pol. B 43 209Year 2012

C4 Neutron skin thickness in neutron rich nuclei: bulk and surface contributions andshell effects

Authors X. Viñas, M. Warda, M. Centelles and X. Roca-MazaJournal Int. J. Mod. Phys. E 21 12500292

Year 2012

C5 Density dependence of the symmetry energy from neutron skin thickness in finitenuclei

Authors X. Viñas, M. Centelles, X. Roca-Maza, and M. WardaJournal AIP Conf. Proc. 1491 101

Year 2012

C6 The pygmy dipole strength, the neutron radius of 208Pb and the symmetry energyAuthors X. Roca-Maza, M. Brenna, M. Centelles, G. Colò, K. Mizuyama, G. Pozzi, X. Viñas

and M. WardaJournal J. Phys. : Conf. Ser. 342 012009

Year 2012

C7 Sensitivity of the electric dipole polarizability to the neutron skin thickness in 208PbAuthors X. Roca-Maza, B. K. Agrawal, G. Colò, W. Nazarewicz, N. Paar, J. Piekarewicz,

P.-G. Reinhard, D. VretenarJournal AIP Conf. Proc. 1491 204

Year 2012

C8 Local covariant density functional constrained by the relativistic Hartree-Fock the-ory

Authors H. Z. Liang, J. Meng, P. Ring, X. Roca-Maza, P. W. ZhaoJournal AIP Conf. Proc. 1491 230

Year 2012

C9 New Skyrme energy density functional for a better description of the Gamow-TellerResonance

Authors X.Roca-Maza, G. Colò and H. SagawaJournal Phys. Scr. T154 014011

Year 2013



http://dx.doi.org/10.1142/S0218301312500292http://dx.doi.org/10.1142/S0218301312500292http://dx.doi.org/10.1063/1.4764212http://dx.doi.org/10.1063/1.4764212http://dx.doi.org/10.1088/1742-6596/342/1/012009http://dx.doi.org/10.1063/1.4764239http://dx.doi.org/10.1063/1.4764245http://dx.doi.org/10.1063/1.4764245http://dx.doi.org/10.1088/0031-8949/2013/T154/014011http://dx.doi.org/10.1088/0031-8949/2013/T154/014011mailto:[email protected]://www.mi.infn.it/~jroca/

C10 Low-lying dipole response in stable and exotic nucleiAuthors M. Brenna, X. Roca-Maza, G. Colò, P. F. Bortignon, K. Mizuyama, and G. PozziJournal Phys. Scr. T154 014020

Year 2013

C11 Microscopic calculations beyond mean-field with zero-range effective interactionsAuthors M. Brenna, G. Colò, P. F. Bortignon and X. Roca-MazaJournal EPJ Web of Conferences 38 04005

Year 2013C12 A beyond-mean-field example with zero-range effective interactions in infinite nu-

clear matterAuthors K. Moghrabi, M. Grasso, X. Roca-Maza, G. Colò, and N. Van GiaiJournal EPJ Web of Conferences 38 06002

Year 2013C13 Nuclear Symmetry Energy: constraints from Giant Quadrupole Resonances and

Parity Violating Electron ScatteringAuthors X. Roca-Maza, B. K. Agrawal, P. F. Bortignon, M. Brenna, M. Centelles, G. Colò,

Li-Gang Cao, N. Paar, X. Viñas, D. Vretenar, and M. WardaJournal EPJ Web of Conferences, in preparation

Year 2013

Conference Talks & SeminarsTitle The nuclear symmetry energy: constraints from giant resonances and parity violat-

ing electron scatteringConference Talk at the International Nuclear Physics Conference 2013

Place Firenze (Italy) 2-7 June.Year 2013

Title The Nuclear Symmetry Energy: constraints from Giant ResonancesConference Invited Seminar at the Physics Department of Surrey University

Place Guildford (UK) 14 May.Year 2013

Title Elastic electron scattering as a revitalized experimental tool in modern nuclearphysics: a theoretical point of view.

Conference Internal Seminar of the Nuclear Physics SectionPlace Milano (Italy) 8 May.Year 2013



http://dx.doi.org/10.1088/0031-8949/2013/T154/014020http://dx.doi.org/10.1051/epjconf/20123804005http://dx.doi.org/10.1051/epjconf/20123806002http://dx.doi.org/10.1051/epjconf/20123806002http://www.mi.infn.it/~jroca/doc/seminars/2013-jun-2-firenze.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2013-jun-2-firenze.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2013-may-14-guildford.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2013-may-8-milano.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2013-may-8-milano.pdfmailto:[email protected]://www.mi.infn.it/~jroca/

Title Local covariant density functional constrained by the relativistic Hartree-Fock the-ory.

Conference Internal Seminar of the Nuclear Physics SectionPlace Milano (Italy) 6 May.Year 2013

Title Parity Violating Asymmetry, Dipole Polarizability, and the Neutron Skin Thickness.Conference Invited talk at the Calcium Radius Experiment (CREX) Workshop at Jefferson Lab

Place Newport News (USA) 17-19 March.Year 2013

Title Electron scattering as a probe of surface properties and proton shell structure ofunstable nuclei.

Conference Invited RIBF Nuclear Physics Seminar at RIKEN Nishina Center.Place Wako (Japan) 8 March.Year 2013

Title The Nuclear Symmetry Energy: constraints from Giant Resonances.Conference Talk at the “Trobades de Nadal”.

Place Barcelona (Spain) 19-20 December.Year 2012

Title New Skyrme energy density functional for a better description of charge-exchangeresonances.

Conference Invited talk at the 19th Nuclear Physics Workshop - Marie & Pierre Curie.Place Kazimierz (Poland) 26-30 September.Year 2012

Title Dipole Polarizability and Parity Violating Asymmetry in 208Pb.Conference Invited key note talk at the 2nd European Nuclear Physics Conference - EuPNC

2012.Place Bucharest (Romania) 16-21 September.Year 2012

Title Dipole Polarizability and Parity Violating Asymmetry in 208Pb.Conference Talk at the conference Nuclear Dynamics and Structure II.

Place Opatija (Croatia) 9-13 July.Year 2012



http://www.mi.infn.it/~jroca/doc/seminars/2013-may-6-milano.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2013-may-6-milano.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2013-mar-17-newportnews.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2013-mar-8-wakoshi.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2013-mar-8-wakoshi.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2012-dic-19-bcn.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2012-sep-26-kazimierz.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2012-sep-26-kazimierz.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2012-sep-16-bucharest.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2012-jul-9-opatija.pdfmailto:[email protected]://www.mi.infn.it/~jroca/

Title Dipole Polarizability and Parity Violating Asymmetry in 208Pb.Conference Invited talk at the workshop The Nuclear Dipole Polarizability and its Impact on

Nuclear Structure and Astrophysics.Place Trento (Italy) 18-22 June.Year 2012

Title Pygmy dipole resonances in stable and unstable nuclei.Conference Talk at the 1st Topical Workshop on Modern Aspects in Nuclear Structure.

Place Bormio (Italy) 22-25 February.Year 2012

Title The pygmy dipole strength, the neutron radius of 208Pb and the symmetry energy.Conference Talk at the II Iberian nuclear astrophysics meeting.

Place Salamanca (Spain), 22-23 September.Year 2011

Title Relativistic mean field interaction with density dependent meson-nucleon verticesbased on microscopical calculations

Seminar University of Coimbra. Physics Department.Place Coimbra (Portugal), 20 September 2011.Year 2011

Title The Dipole Strength: Microscopic Properties and Correlations with the SymmetryEnergy and the Neutron Skin Thickness

Conference Invited talk at the International Symposium on Nuclear Symmetry Energy.Place Northampton (MA), 17-20 June.Year 2011

Title Density dependence of the nuclear symmetry energy estimated from neutron skinthickness in finite nuclei.

Conference Talk at the JAPAN-ITALY EFES Workshop.Place Turin (Italy), 6-8 September.Year 2010

Title Density dependence of the nuclear symmetry energy estimated from neutron skinthickness in finite nuclei.

Seminar University of Milan. Physics Department.Place Milan (Italy), 3 November.Year 2010



http://www.mi.infn.it/~jroca/doc/seminars/2012-jun-18-trento.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2012-feb-22-bormio.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2011-sep-23-salamanca.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2011-sep-20-coimbra.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2011-sep-20-coimbra.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2011-jun-17-northampton.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2011-jun-17-northampton.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2010-sep-8-torino.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2010-sep-8-torino.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2010-nov-3-milano.pdfhttp://www.mi.infn.it/~jroca/doc/seminars/2010-nov-3-milano.pdfmailto:[email protected]://www.mi.infn.it/~jroca/

Title The Smoothness of Physical ObservablesSeminar University of Barcelona. Physics Department.

Place Barcelona (Spain), 29 May.Year 2009

Brief Professional BiographyResearch Activities

I started my research activity in 2005 together with my DEA studies. Currently and during my PhDI focused on different aspects in Nuclear Physics. One of the main topics is the nuclear symmetryenergy and its connection to ground state and excited state properties of finite nuclei. The nuclearsymmetry energy is a basic property of the nuclear Equation of State, it represents the energy costper particle to convert all protons into neutrons in symmetric nuclear matter, and still lacks of anaccurate characterization. It impacts on a variety of physical systems, from the very big: the sizeof a neutron star or its composition and structure [P1,C1]; to the very small: the neutron skinthickness of a heavy nucleus [P2,P3,P4,P5,P14,P20,P21,C2,C3,C4,C5].

I have also devoted part of my research to the theoretical study of elastic electron scattering bystable and exotic nuclei [P6,P17]. This is mainly motivated by the advent of new Rare Ion BeamFacilites around the world that host projects (like ELIse at GSI, Germany, or SCRIT at RIKEN,Japan) aimed at measuring elastic electron cross sections in exotic nuclei.

The gained experience has allowed us to connect our previous knowledge on the symmetry energy,the neutron skin thickness in nuclei and the elastic electron scattering by nuclei to study the NuclearMean Field predictions for the measured Parity Violating Asymmetry in 208Pb at the JeffersonLaboratory (USA) [P5,P7,C6].

In parallel to all these investigations, I have always been concerned about the connection betweenab initio calulations of infinite nuclear matter based on empirical nucleon-nucleon potentials (such asBrueckner-Hartee-Fock or Dirac-Brueckner-Hartee-Fock calculations) and finite nuclei. Nowadays,medium-heavy and heavy mass nuclei can only be extensively calculated by using Effective MeanField techniques and the predictions of this approach for infinite nuclear matter are not always ingood agreement with available ab initio calculations. As a first attempt to build a bridge betweenab initio and effective mean field theories, we have developed a relativistic mean field model withdensity dependent meson-nucleon vertices based on state-of-the-art ab initio results [P8].

We have also analyzed theoretically the effects of the symmetry energy on the Giant MonopoleResonance —a nuclear excitation of atomic nuclei— in neutron-rich nuclei [P9]; and a systematicstudy of nuclear charge radii along the whole periodic table by taking advantage of the Garvey andKelson Relations extended for such an investigation[P10].

In 2010, at the Sezione di Milano of the INFN, my research took a different direction. Althoughmany times related with my previous experience, I started the study of nuclear excitations withinthe Random Phase Aproximation (RPA) and the Particle Vibration Coupling approach. In partmotivated by my previous experience on the symmetry eneregy and in part motivated by the factthat such a property may be related to a new exotic mode that appear in neutron-rich nuclei, namelyPygmy Dipole Resonance (the group in Milano has predicted such a relation but it is still under



http://www.mi.infn.it/~jroca/doc/seminars/2009-may-29-bcn.pdfmailto:[email protected]://www.mi.infn.it/~jroca/

debate), we started a detailed investigation of such an exotic mode in different nuclei and by meansof different Skyrme mean field interactions [P11,C6,C10]. Moreover, we are currently trying toconfirm or disproof the correlation between the Pygmy Dipole Resonance and the symmetry energyby means of a more rigorous statistical analysis (covariance analysis of some selected mean-fieldmodels) as well as the model correlation between the dipole polarizability and the neutron skinthickness of medium and heavy nuclei [P12,P19,C7]. We argue in [P12,C7] that experiments on thedipole polarizability can complement PREx-like experiments and allow us to better constraint thedensity dependence of the symmetry energy at saturation. In addition, we show in [P19] that thedipole polarizability in heavy mass nuclei times the symmetry energy at saturation correlates withthe neutron skin thickness and also with the slope of the symmetry energy at saturation. Hence,further encouraging measrements on such an observable.

At the same time, I had the opportunity to learn about the Particle Vibration Coupling approach andhelp in the supervision of the Master thesis of Giacomo Pozzi (see teaching activity). In this thesis,G. Pozzi developed an original model for the calculation of the dipole response of 67,69Ni motivatedby the need of understanding the measurements on those nuclei performed by the experimentalgroup at Milano.

Parallel to that, we started also new collaborations. The first one is with the Orsay group with whichwe try to develope a Skyrme-like Beyond Mean Field approach (first order in perturbation theorybeyond the mean field) for the calculation of infinite nuclear matter [P13,C12] and eventually finitenuclei [C11] —currently under development. In a second project, in collaboration between Milanoand Aizu, we built a new Skyrme interaction (SAMi) which overcomes some drawbacks of existingmean field models such as the inaccurate description of spin-isospin properties in nuclei [P15,C9].In the near future, we also plan to include the tensor channel in the SAMi effective interactionin order to further improve the accuracy in the description of charge-exchange resonances. In athird project, I had also the oportunity to collaborate with the Beijing group in developing a newtechniche for expressing Fock terms in a local from [P16,C8]. This work may provide importantimplications on both the building of new effective interactions and the developement of beyondmean-field calculations where the effect of exchange terms should be included. On this regard, ourfirst step is developing a point coupling relativistic effective interaction based on a similar fittingprocedure than in [P8] but in this case including the Fierz transformations in order to account forthe effect of the exchange (or Fock) terms.

On the other side, the use of a new experimental technique in combination with a monocromatic andpolarized high energy γ−ray source available at Duke University has allowed to improve the accuracyon the determination of the Isovector Giant Quadrupole Resonance. This fact has motivated ourtheoretical investigation on such a collective nuclear mode on the bases of different microscopicmodels. Specifically, we have anayzed the connection of the excitation energy of the IVGQR[P18,C13] and of the quadrupole polarizability [C13] with the isospin properties of the nucleareffective interaction.

Following our studies on the neutron skin thickness, we have recently analyzed the effects of thesingle-particle properties on its formation and, in general, on the nuclear surface. For this purpose,we have analyzed the predictions of different mean-field models along some selected isotopic chains[P21].

As previously mentioned, the symmetry energy is one of the common threads in my theoreticalinvestigations and the experience gained on this topic as well as the different collaborations settled




along my scientifical carrear have allowed me to participate in a summary paper writen as anoutcome of the NuSYM symposium celebrated in 2011 in the Smith College, Northampton (USA)[P14] and also to be invited together with X. Viñas and M. Centelles from Barcelona Universityand M. Warda from Lublin University to write a review paper on a special volume on the nuclearsymmetry energy to be published by the European Physical Journal A [P20].

Future Perspectives

Many attempts have been made to give an approximate solution to the nuclear many body problemin the past and this effort continues also in the present. One of the most successful and commonlyused approaches to describe the nucleus is based on effective interactions, either in the relativistic orin the non-relativistic frameworks as pointed out earlier. Effective interactions have been traditionallyimplemented at the mean-field level where an independent particle picture is adopted. Such anapproach provides a rather accurate description of the bulk properties of nuclei and, generally, lessaccurate predictions for detailed spectroscopic properties, excitations and reaction processes in nuclei.For this reason, we are in the first stages of development of a new approach beyond the mean-fieldfor the calculation of finite nuclei: (i) as a first test, the first order correction to the mean-fieldenergy will be included; (ii) more realistically, instead, the interaction between the nucleonic and thevibrational degrees of freedom will be then studied at the same level of approximation. In both cases,the parameters of the effective interaction will be refitted to reproduce some selected empirical data.Such a strategy aims to provide a unified description not only of the bulk properties of nuclei butalso of the nuclear excitations.

In close connection, we also plan to study the low-lying dipole strength in odd nuclei by usingthe particle-vibration coupling approach and a study of spin-isospin resonances in exotic nucleiusing a non-relativistic SAMi-like interaction with tensor terms in the Hamiltonian with the aimof understanding and further overcoming some drawbacks of existing effective interactions in thedescription of spin-isospin properties in nuclei.

As briefly highlighted, we also plan to build a point coupling relativistic effective interaction where theeffective Lagrangian contains all possible channels allowed by the symmetries, that is, scalar, vector,pseudo-scalar, pseudo-vector and tensor terms all in both the isoscalar and isovector channels. Onlyfour of these channels will be fitted to experimental data and the rest will be fixed self-consistentlyduring the Hartree-calculations via the Fierz transformations. In this way the parameter spaceis reduced, the predictive power of the approach is not compromised and the tecnical difficultiesinherent in Fock terms are avoided keeping its effects in an effective but efficient way.

The recent experimental determination of the analyzing power in polarized electron scattering off208Pb by the PREx collaboration at the Jefferson Laboratory have settled a new puzzle for nucleartheoriticians. The analyzing power, or transverse asymmetry, is zero at the first Born approximationand non-zero in the experiment. Actually, it has been shown to be dominated by two photonexchange contributions in light nuclei. However, the same type of calculations fail dramaticallyfor the case of 208Pb. We plan to include to the effect of Coulomb distortions –thought to beimportant in heavy mass nuclei– in the calculations of this observable assuming an imaginary partin the optical potential that is though to simulate the effect of two (or more) photon exchange.

Related with the measurement of the analyzing power in polarized electron scattering, we are startinga collaboration with the experimental group at the Jefferson Laboratory responsible of the Mottpolarimeter with the aim of improving its performance. This will impact on many experiments




planed before and after the upgrade of this important facility for the study of the fundamentalinteractions.

Finally, the Self-Confining Rare Isotope Target (SCRIT) facility is planed to become completelyoperative the next year and will become a world-unique experimental tool for the study of fundamentalproperties in exotic nuclei. The first measurements will determine the unknown electromagneticdistribution of unstable Sn (Z=50) isotopes via elastic electron scattering. The initial target willbe 132Sn predicted to be a doubly magic nucleus with spherical shape by succesful nuclear models.Although not planned yet, the measurement of the dipole response in exotic nuclei might be feasibleusing the SCRIT facility via the experimental study of inelastically scattered electrons at forwardangles. Motivated by this exciting experimental developements, we plan to investigate the influenceof the experimental determination of the electromagnetic charge radius and the electric dipolepolarizability in an exotic nucleus such as 132Sn on the characterization of the isovector properties ofthe nuclear effective interaction. If succesful, the measurement of this two observables employing thesame facility and for different isotopes will be strongly encouraged since systematic measurementswill reduce the experimental uncertainties on the studied quantities and, hopefully, on the propertiesof the symmetry energy around saturation density.




Personal InformationPresent positionPostDoc - researcher

EducationPhD ThesisAdvanced Studies Diploma ThesisMaster Degree in Physics

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AwardsFellowshipsComputer skillsLanguagesBibliometric indicators of my publicationsSource: Thompson & Reuters AuthorID: E-4541-2013Source: Scopus (no data on 2013) AuthorID: 25641764000Source: Google Schoolar Citations

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javier roca maza – curriculum vitaejroca/doc/cv/cv-eng-140110.pdf · 2014. 1. 10. · javierroca...

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