Theoretical nuclear physics

Transcription

1 Theoretical nuclear physics Laura Elisa Marcucci (Univ. Pisa & INFN-Pisa) The Pisa Group Ignazio Bombaci (Univ. Pisa & INFN-Pisa) Angela Bonaccorso (INFN-Pisa) Alejandro Kievsky (INFN-Pisa) Laura Elisa Marcucci (Univ. Pisa & INFN-Pisa) Sergio Rosati (Prof. Emerito, Univ. Pisa & INFN-Pisa) Michele Viviani (INFN-Pisa) Adelchi Fabrocini (Univ. Pisa & INFN-Pisa, )

2 Nuclei: system of interacting particles (neutron and proton = nucleon) Nucleon: system of elementary particles (quarks) held together by gluons 270 isotopes on Earth 1000 (not stable) isotopes, with A=2 300

3 Laboratories

4 Lawrence Livermore National Laboratory... and in Japan (J-PARC, SPring-8, KEK, RIKEN,...)

5 Best laboratories... ever! A computer simulation, based on theoretical predictions, of the first three seconds of a supernovae explosion [University of Chicago Flash Center] Nuclear astrophysics Nuclear physics

6 Research activities in nuclear physics and astrophysics 1) What governs the transition of quark and gluons into nucleons and pions Which are the right degrees of freedom What is the nature of nuclear force 2) What is the origin of simple patterns in complex nuclei Where are the proton/neutron drip lines 3) What is the nature of neutron stars and dense hadronic matter 4) What are the nuclear reactions that drive stars and stellar explosions... and many more astrophysical questions 1) & 4): A. Kievsky, L.E. Marcucci, S. Rosati, M. Viviani 2) A. Bonaccorso 3) I. Bombaci

7 Research activity 1: A. Kievsky, L.E. Marcucci, S. Rosati, M. Viviani Nuclear interaction: VNN+VNNN Until 15 years ago VNN + VNNN semiphenomenological VNN with 40 parameters fitted to A=2 data 2/datum 1 VNNN : 2-3 parameters fitted to B(A=3,4) no simple connection to QCD Then... chiral effective field theory (χeft) and Lattice QCD

8 Chiral Effective Field Theory (χeft) QCD quark and gluons ( heavy degrees of freedom) Nuclear physics nucleons and pions ( light degrees of freedom) EFT processes with E p mπ ΛQCD 1 GeV heavy d.o.f. integrated out contact interactions with light d.o.f. and lowenergy constants (LECs) obtained from experiment perturbative theory: matrix elements O(p/ΛQCD)ν χeft implement EFT and spontaneous breaking of QCD's chiral symmetry Advantages: a) right treatment of πn interaction b) nuclear force hierarchy accurate VNN+VNNN Disadvantage: limited to processes occurring at low-energy E 1-2 mπ S. Weinberg, Phys. Lett. B 251, 288 (1990); Nucl. Phys. B 363, 3 (1991) V. Bernard, N. Kaiser, and U.G. Meissner, Int. J. Mod. Phys. E 4, 193 (1995)... E. Epelbaum et al., Phys. Rev. C 66, (2002) D.R. Entem and R. Machleidt, Phys. Rev. C 68, (2003) E. Epelbaum, Prog. Part. Nucl. Phys. 57, 654 (2006) E. Epelbaum, H.W. Hammer, and U.G. Meissner, Rev. Mod. Phys. 81, 1773 (2009) REVIEW

9 Pisa: only available method to study A=3,4 scattering states at low-energies ( kev astrophysical interest) Accurate techniques to solve the few-body nuclear problem A=3,4 bound and zero-energy scattering states VNN VNN + VNNN VNN VNN + VNNN AV18 AV18/UIX N3LO N3LO/N2LO Exp. B(3H) [MeV] B(3He) [MeV] B(4He) [MeV] and [fm] (10) 4 and [fm] (2) 1 an H [fm] (29) 4.45(10) 3 an H [fm] (11) 3.32(2) 3 3 A. Kievsky et al., J. Phys. G: Nucl. Part. Phys. 35, (2008)

10 p-3he elastic scattering M. Viviani et al., arxiv:

11 3 Application to reactions of astrophysical interest: p+d 3He+γ - pp chain - Big Bang Nucleosynthesis (one of the largest uncertainty for the calculated 7Li abundance) Reactions of astrophysical interest studied over the years: p+p d+e++νe p+3he 4He +e++νe T.S. Park et al., Phys. Rev. C 67, (2003) n+d 3H+γ L. Girlanda et al., Phys. Rev. Lett. 105, (2010) μ +d n+n+νμ μ +3He 3H+νμ L.E. Marcucci et al., Phys. Rev. C 83, (2011) M. Viviani et al., Phys. Rev. C 61, (2000) L.E. Marcucci et al., Phys. Rev. C 72, (2005) E.G. Adelberger et al., arxiv: , Rev. Mod. Phys. in press

12 Research activity 2: A. Bonaccorso Light nuclei weakly bound, p Halo, n Halo, Borromeian nuclei Sn T1/2 6 He 0.9 MeV 806 msec 8 B 0.14 MeV 770 msec sec 11 Be 0.5 MeV 11 Li 0.22 MeV 8.5 msec 17 F 0.6 MeV 64.5 sec 0.5 MeV 49 msec 19 C anomalous large radii large diffuseness inversion of shells long tail of the wave functions I. Tanihata, Prog. Part. Nucl. Phys. 35, 505 (1995) Fundamental research to define the drip lines

13 Be-10Be-11Be 9 9 Be 10 Be LNS - Catania ISOLDE - CERN Be 11 dσ/dω elastic reduced by ~ 50% for 11Be Possible explanation: breakup channel neutron-halo A. Di Pietro et al., Phys. Rev. Lett. 105, (2010) asi = diffuseness. For normal systems: asi ~ 0.65 fm Predicted by A. Bonaccorso and F. Carstoiu, Nucl. Phys. A 706, 322 (2002): asi =3.2 fm

14 Borromean and unbound nuclei Be+12C n + 12 Be + X 14 First evidence of a p1/2 g.s. for 13Be H. Simon et al., Nucl. Phys. A 791, 267 (2007) - GSI data G. Blanchon et al., Nucl. Phys. A 784, 49 (2007) - theory G. Blanchon, PhD Thesis, Univ. of Pisa 2008, Studies to determine Vn-core predict structure of other nuclei recently confirmed by Y. Kondo et al., Phys. Lett. B 690, 245 (2010) G. Blanchon et al., Phys. Rev. C 82, (2010)

15 Li-11Li Li(2 H, p) Li ground state is a virtual s-state (see cold atoms) Spectrum of 10Li from 11Li fragmentation 11 Li+12C n + 9 Li + X p s s p d G. Blanchon et al., Nucl. Phys. A 739, 259 (2004) G. Blanchon et al., Nucl. Phys. A 791, 363 (2007) H.B. Jeppensen et al., Phys. Lett. B 642, 449 (2006)

16 Research activity 3: I. Bombaci Neutron Stars M = (1-2) MSUN R ~ 10 km ρc = (4-8) ρ0 R/Rg ~ 2-4 Space-time in strong gravity (GR) Dense hadronic matter EOS Quantum many-body syst. under strong interactions MSUN = x 1033 g (mass of the Sun) ρ0 = 2.8 x 1014 g/cm3 (nucl. saturation dens.) Rg 2GM/c2 (Schwarzschild radius) Structural properties of Neutron Stars measured properties of Neutron Stars Emission models (PSR mechanism, NS atmosphere). ISM composition. Distance. Observational data

17 Nucleonic Stars Hadronic Stars Hyperon Stars Hybrid Stars Quark Stars Strange Stars Bombaci and Drago, INFN notizie 13, 15 (2003) Thecore coreof ofthe themost mostmassive massive The NeutronStars Stars isisone oneof ofthe the Neutron bestcandidates candidatesin inthe the best Universewhere whereaadeconfined deconfined Universe phaseof ofhadronic hadronicmatter matter phase (quarkmatter) matter)can canbe befound found (quark

18 Microscopic EOS for hyperonic matter and hyperonic star structure EOS for hybrid star structure I. Vidaña et al., Astron. & Astrophys. 399, 687 (2003) I. Bombaci, Eur. Phys. J. A 31, 810 (2007)

19 Quark matter nucleation in Neutron Stars and in proto-neutron Stars Hadronic Stars above a threshold value of their gravitational mass are metastable to the conversion to Quark Stars (QS) 1) Mcr, critical mass of HS 2) Two families of compact stars 3) Stellar conversion HS QS Econv 1053 erg possible energy source for some GRBs Z. Berezhiani et al., Astrophys. Jour. 586, 1250 (2003) I. Bombaci et al., Astrophys. Jour. 614, 314 (2004) G. Lugones and I. Bombaci, Phys. Rev. D 72, (2005) I. Bombaci et al., Astron. & Astrophys. 462, 1017 (2007) I. Bombaci et al., Phys. Rev. D 77, (2008) I. Bombaci et al., Phys. Lett. B 680, 448 (2009) I. Bombaci et al., Astron. & Astrophys. 528, A71 (2011)

20 Where are we going: research activity 1 NNN force from χeft at the same χ-order as NN force Solve old-standing puzzles in few-body systems L. Girlanda et al., arxiv: , submitted to Phys. Rev. C Use χeft for nuclear electro-weak current operators: consistent study of fundamental reactions S. Pastore et al., Phys. Rev. C 80, (2009) L. Girlanda et al., Phys. Rev. Lett. 105, (2010) L.E. Marcucci et al., Phys. Rev. C 83, (2011) Ab initio calculations of A 4 nuclear systems Few techniques for A>4 nuclear systems (NCSM, GFMC/VMC, AFDMC); none for scattering states Hyperspherical Harmonics methods (Pisa) can be pushed to study these systems M. Gattobigio et al., Phys. Rev. C 83, (2011) Studies of Parity Violating (PV) strong interaction (W/Z exchange between q in N & q in π): large experimental and theoretical activity R. Schiavilla et al., Phys. Rev. C 78, (2008) M. Viviani et al., Phys. Rev. C 82, (2010)

21 Detailed study of reactions of astrophysical interest L.E. Marcucci et al., Nucl. Phys. A 777, 111 (2006) Big Bang Nucleosynthesis (BBN) abundances of primordial light nuclei (d,3he, 4He, 7Li) Cosmic Microwave Background

22 Where are we going: research activity 2 Until 2009: EURISOL Design Study possibility to influence the different research-lines

23 Where are we going: research activity 3 A massive NS: PSR J M = (1.97 ± 0.04) MSUN Demorest et al., Nature 467, 1081 (2010) Microscopic EOS for hyperonic matter: very soft EOS non compatible with PSR J Need for extra pressure at high density Need for improved VNY and VYY and three-body forces (VNNY VNYY VYYY) Large experimental activity (GSI, J-PARC) A preliminary study: I. Vidaña et al., Eurphys. Lett. 94, (2011)

24 Summarizing... Recent activity ( ) 37 publications on peer-reviewed journals (19 on journals with IF > 3) 45 contributions to international conferences (34 invited) Following arxiv: (WoS, PY=2008, SA= Nucl. Phys., TS=theory) Top-10 % papers All papers