nuclear physics at the unitn - nupecc · francesco pederiva. giuseppina orlandini, mini-workshop...

Giuseppina Orlandini, Mini-Workshop NUPECC, ECT*, March 11, 2016

Nuclear Physics at the Nuclear Physics at the UniTnUniTn



Staff members: Winfried Leidemann Giuseppina Orlandini Francesco Pederiva




PhD Students: Paolo Andreatta Lorenzo Andreoli Lorenzo Contessi Sergio Deflorian Fabrizio Ferrari Ruffino





Many international collaborations (USA, Canada, Israel, Russia)





Many international collaborations (USA, Canada, Israel, Russia)

All are also INFN affiliated


Many active international collaborations also with:Many active international collaborations also with:

ex Trento students:

Sonia Bacca (TRIUMF) Stefano Gandolfi (Los Alamos) Diego Lonardoni (Argonne) Mirco Miorelli (TRIUMF) Alessandro Roggero (INT- Seattle)

ex ECT* postdocs:

Nir Barnea (Hebrew Univ. Jerusalem)

ECT*/INFN postdoc:

Chen Ji


““ Ab initioAb initio studies of nuclear studies of nuclear structure and reactions structure and reactions ““

➔ Aim:

➔ Methods:

➔ Some illustrative results:

The NP activity can be summarized under the titleThe NP activity can be summarized under the title

a) structure b) reactions


AIM:AIM:


Low-Energy QCD

Nuclear observables

Aim 1: Help building the bridge between Nuclear Physics and QCD


Low-Energy QCD

Nuclear observables

“effective” degrees of freedomprotons, neutrons, pions



Low-Energy QCD

Nuclear observables


Nuclear Interactions NN, 3N ...phenomenological, meson exchange,

EFT (consistent & improvable )

Nucleons and pions on the

Lattice



Low-Energy QCD

Nuclear observables

Ab initio Many-body methods

Ab initio Few-body methods


\Nuclear Interactions NN, 3N ...phenomenological, meson exchange,



Lattice



Low-Energy QCD

Nuclear observables







Lattice



Low-Energy QCD

Nuclear observables



benchmarks





Lattice



Low-Energy QCD

Nuclear observables





Lattice

valid

atio

n


Pre

dict

ion




Aim 2: Connections between Nuclear Physics and Nuclear Astrophysics


Nuclear Astrophysics

Nuclear Physics




Nuclear Physics


Abundances Nucleosynthesis Neutron Stars Spectrum of GW



Nuclear Physics

Astrophysical models





Nuclear Physics




NP Inputs: E.W. and H processes EoS Hypernuclei





Nuclear Physics








Nuclear Physics




Val

idat

ion

Pre

dic

tion




METHODS:METHODS:


Ab initioAb initio methods methods “Modern ab initio approaches and applications in few-nucleon physics with A ≥ 4”

• Solution of relevant many-body QM equation, • given an interaction as input, • with approximations improvable in a controlled way • ( convergence, error estimate benchmark)


rea

ctio

ns

stru

ctu

re

Few-body Many-body

Hyperspherical Harmonics

(HH)

Monte Carlo(MC)

Integral Transforms(IT)

The basic methodsThe basic methods

Coupled Cluster(CC)


Ab initio methods developed by Trento NP members: Ab initio methods developed by Trento NP members:


Ab initio methods developed by Trento NP members Ab initio methods developed by Trento NP members

EIHHEIHH ≡≡ EEffective ffective IInteraction nteraction HHyperspherical yperspherical HHarmonics armonics rapid convergence of HH expansions for bound states. Allows A>3---->6,7??rapid convergence of HH expansions for bound states. Allows A>3---->6,7?? N. Barnea , W. Leidemann, G. Orlandini (2000)N. Barnea , W. Leidemann, G. Orlandini (2000)

AFDMC AFDMC ≡ ≡ AAuxiliary uxiliary FField ield DDiffusion iffusion MMonte onte CCarlo arlo different from GFMC allows to extend MC calculations to a large number of different from GFMC allows to extend MC calculations to a large number of

particles particles

S. Fantoni, S. Gandolfi, F. Pederiva, K. Schmidt (2003)S. Fantoni, S. Gandolfi, F. Pederiva, K. Schmidt (2003)

CIMCCIMC ≡ ≡ CConfigurationonfiguration IInteraction nteraction MMonte onte CCarloarlo

combination of coupled cluster and Monte Carlo theoriescombination of coupled cluster and Monte Carlo theories

A. Roggero, A. Mukherjee, F. Pederiva (2013)A. Roggero, A. Mukherjee, F. Pederiva (2013)

LITLIT ≡ ≡ LLorentzorentz IIntegral ntegral TTransform ransform for Ractions. for Ractions. Reduces theReduces the continuum state problem to acontinuum state problem to a b.s b.s problem. problem.

V. Efros, W. leidemann, G. Orlandini (1994)V. Efros, W. leidemann, G. Orlandini (1994)





particles particles



combination of combination of coupled clustercoupled cluster and Monte Carlo methods and Monte Carlo methods








particles particles



combination ofcombination of coupled cluster coupled cluster and Monte Carlo theoriesand Monte Carlo theories




These are methods for nuclear structureThese are methods for nuclear structure (bound states)(bound states)





particles particles



combination of combination of coupled clustercoupled cluster and and Monte CarloMonte Carlo methods methods


LITLIT ≡ ≡ LLorentzorentz IIntegral ntegral TTransform ransform Reduces theReduces the continuum continuum problem to a problem to a bound state bound state problemproblem


method for reactions:method for reactions:

G. Orlandini – Mini-Workshop NUPECC, ECT*, March 11, 2016

Integral transform approach

Φ = ∫ dE K( E, f ( E )



Φ = ∫ dE K( E, f ( E )

Very useful if one IS NOT able to calculate f (E ), but IS able to calculate Φ



Φ = ∫ dE K( E, f ( E )

Very useful if one IS NOT able to calculate f (E ), but IS able to calculate Φ It requires to invert the integral transform



Φ = ∫ dE K( E, f ( E )


Physical application:

f (E ) is a cross section to states in the many-body continum.



Φ = ∫ dE K( E, f ( E )


Physical application:

f (E ) is a cross section to states in the many-body continum.The choice of appropriate K( E, makes it possible to

calculate Φ with bound-state methodsand to invert the transform


Some illustrative results:Some illustrative results: a) structure


Ex. N.1: The bridge between LQCD and

Nuclear Physics (if the pion were “heavy”!!)

Unquenched Unquenched LLattice attice QCDQCD with with heavy pionsheavy pions is now able to is now able to give some 1,2,3,(4) - nucleon massesgive some 1,2,3,(4) - nucleon masses

see e.g. M.Savage - see e.g. M.Savage - arXiv:1510.01787arXiv:1510.01787..





see e.g. M.Savage - see e.g. M.Savage - arXiv:1510.01787arXiv:1510.01787.. Using EFT one can build a Using EFT one can build a heavy pion (–-> pionless)heavy pion (–-> pionless)

Lagrangian ---> Hamiltonian and Lagrangian ---> Hamiltonian and fit LQCD datafit LQCD data





see e.g. M.Savage - see e.g. M.Savage - arXiv:1510.01787arXiv:1510.01787.. Using EFT one can build a Using EFT one can build a heavy pion (–-> pionless)heavy pion (–-> pionless)

Lagrangian ---> Hamiltonian and Lagrangian ---> Hamiltonian and fit LQCD datafit LQCD data

Using HH and AFDMC one can calculate Using HH and AFDMC one can calculate

nuclear structure properties nuclear structure properties


N. Barnea, L. Contessi, D. Gazit, F. Pederiva and U. van Kolck



LQCD NP with EFT


Z

Z

Z

Z

S

Ex. N.2: Ex. N.2: HyperHypernuclear Physicsnuclear Physics


the bridge to QCD with the bridge to QCD with strangenessstrangeness EoSEoS with with hyperonshyperons has consequences on the has consequences on the

structure of neutron starsstructure of neutron stars

HypernucleiHypernuclei



structure of neutron starsstructure of neutron stars However, the construction of a YN potential is much However, the construction of a YN potential is much

more problematic due to lack of scattering datamore problematic due to lack of scattering data

––-> Interactions (phen. - meson ex. - EFT) have to -> Interactions (phen. - meson ex. - EFT) have to be fitted on Ebe fitted on E

BB of existing hypernuclei of existing hypernuclei




structure of neutron starsstructure of neutron stars However, the construction of a YN potential is much However, the construction of a YN potential is much

more problematic due to lack of scattering datamore problematic due to lack of scattering data

––-> Interactions (phen. - meson ex. - EFT) have to -> Interactions (phen. - meson ex. - EFT) have to be fitted on Ebe fitted on E

BB of existing hypernuclei of existing hypernuclei

Importance of ab initio calculations of both finite Importance of ab initio calculations of both finite systems Esystems E

BB and EoS ! and EoS !

Importance of benchmarks between Few-body and Importance of benchmarks between Few-body and Many-Body methods Many-Body methods



Benchmark between Benchmark between HHHH and and MCMC

Z

ZF.Ferrari Ruffino et al. (Preliminary!)

AV4' and U are “phenomelogical” and N potentials.However..


Since has T=0, N comes from 2 exchange e.g.

N

N


N

N

N

N

N

N

Then 3-body force is as important


Phenomenological fittedwith AFDMC to data

on EB

Add as explicit d.o.f. in HH and use meson exchange and

potentials (Nijmegen)

Either: Or:

Then 3-body force is as important


Equation of State from AFDMC calculations

-neutron matter-neutron matter

Phenomenological fitted with AFDMC

to data on EB

D.Lonardoni, A.Lovato, S.Gandolfi, F.Pederiva Phys. Rev. Lett. 114, 092301 (2015)


YNN repulsion pushes theonset of hyperons at muchhigher densities

N

NN

of

Equation of State from AFDMC calculations

-neutron matter-neutron matter

D.Lonardoni, A.Lovato, S.Gandolfi, F.Pederiva Phys. Rev. Lett. 114, 092301 (2015)


Implication for Implication for Neutron StarsNeutron StarsMass of Neutron Star ( in solar mass units)


Hyperons not present in Neutron Star cores

Too much energy needed to win repulsion

Implication for Implication for Neutron StarsNeutron Stars Mass of Neutron Star ( in solar mass units)


Alternative to the purely phenomenological approach to hypernuclear N and NN interactions :

Add as explicit d.o.f. and use meson exchange

and potentials (Nijmegen)


Add as explicit d.o.f. and use meson exchange

and potentials (Nijmegen)

Benchmark results HHH versus Gaussian Expansion Method

(by Hiyama et al. )

F.Ferrari Ruffino et al. (Preliminary)

Alternative to the purely phenomenological approach to hypernuclear N and NN interactions :


Some illustrative results:Some illustrative results: b) Reactions


Ex. N.3: Ex. N.3: Monopole excitation of Monopole excitation of 44HeHe

by (e,e') or (by (e,e') or ( ')') Very narrow Very narrow 00+ + resonanceresonance in the continuum in the continuum

Transition form factor FTransition form factor Ftrtr(q) has been (q) has been

measured by (e,e') [(measured by (e,e') [(') has been proposed]') has been proposed]






Using IT method (Using IT method (LLITIT) coupled with ) coupled with EIHHEIHH b.s. b.s. method one can calculate Fmethod one can calculate F

trtr(q) ((q) (separating separating

resonance and background contributions!resonance and background contributions!))






Using IT method (Using IT method (LLITIT) coupled with ) coupled with EIHHEIHH b.s. b.s. method one can calculate Fmethod one can calculate F

trtr(q) ((q) (separating separating

resonance and background contributions!resonance and background contributions!)) We find large potential dependenceWe find large potential dependence We find hints for a “breathing mode” We find hints for a “breathing mode”

interpretationinterpretation


S.Bacca N.Barnea,W.Leidemann and G.O.et al. PRL 110 042503 (2013)

Very large potential dependence !!!

F t

r

EIHH + LIT methodsBoth phenomenological and EFT potentialsWith and without 3-body forces


In a recent LIT calculation W. Leidemann PRC 91, 054001(2015)

also the small resonance width could be resolved with a proper choice of basis (HH basis only for A-1 nucleons)


In a recent LIT calculation W. Leidemann PRC 91, 054001(2015)

also the small resonance width could be resolved with a proper choice of basis (HH basis only for A-1 nucleons)

Calculated width: th

keV

Experimental width: exp

keV


Ex. N.4: Ex. N.4: E1 cross sections & Dipole E1 cross sections & Dipole

PolarizabilitiesPolarizabilities Giant Resonances of Giant Resonances of 44He, He, 77Li, Li, 1616O, O, 4040Ca ... Ca ...

Recent and planned measurements of Recent and planned measurements of 2222O and O and 4848CaCa




Recent and planned measurements of Recent and planned measurements of 2222O and O and 4848CaCa Coupling IT method (Coupling IT method (LLIT and IT and SSITIT) with ) with EIHHEIHH

and and CCCC b.s. methods we have been able to predict: b.s. methods we have been able to predict:






A pronounced GR also in 4He (confirmed by experiments at Lund and recently at TUNL)







the centroid of the GR in 16O










A pronounced GR also in 4He

(confirmed by experiments at Lund and recently at TUNL)

the centroid of the GR in 16O low energyenergy peak in 22O











the centroid of the GR in 16O low energyenergy peak in 22O Polarizability of 48Ca






S. Bacca et al. Phys. Rev. C 90, 064619 (2014)

LIT +CC(SD) methods

N3LO EFT potential

S. Bacca, et al.Phys.Rev.Lett. 111 122502 (1913)


A good kernel for Monte Carlo methods:

combination of Sumudu kernels:

(A.Roggero, F. Pederiva, G.O. PRB 88, 094302 (2013))


KP( e – eP

(A.Roggero, F. Pederiva, G.Orlandini arXiv-1209.5638)

3. arXiv:1209.5638

http://arxiv.org/abs/1209.5638


A good kernel for Monte Carlo methods:


KP( e – eP

KP(

(A.Roggero, F. Pederiva, G.O. PRB 88, 094302 (2013))


G.Hagen at al.

Dipole Polarizability of 48Ca(SIT + CC methods)

48Ca

Exp. Rp

Blue band: Various EFT potentials


The np group at UnitnThe np group at Unitn


The np group at UnitnThe np group at UnitnMarco TRAINI


The np group at UnitnThe np group at UnitnRenzo LEONARDI


THANK YOU!THANK YOU!

The np group at UnitnThe np group at UnitnRenzo LEONARDI

nuclear physics at the unitn - nupecc · francesco pederiva. giuseppina orlandini, mini-workshop...

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