Lunch Seminar, July 4Lunch Seminar, July 4

Current understanding of the nuclear forceCurrent understanding of the nuclear force

Hiroyuki KamanoHiroyuki Kamano

http://www.kek.jp/ja/news/topics/2007/INPC2007.html

& Symposium for Centennial Celebration of Hideki Yukawa (June 3)& Symposium for Centennial Celebration of Hideki Yukawa (June 3)

Impact and contribution of Yukawa’s meson theory Impact and contribution of Yukawa’s meson theory to the modern nuclear physics were mentioned.to the modern nuclear physics were mentioned.Impact and contribution of Yukawa’s meson theory Impact and contribution of Yukawa’s meson theory to the modern nuclear physics were mentioned.to the modern nuclear physics were mentioned.

W. Weise “Overview and perspectives in Nuclear Physics” : Plenary talk in W. Weise “Overview and perspectives in Nuclear Physics” : Plenary talk in INPC2007INPC2007

or or heavy mesonheavy meson (( … …)) exchangeexchangeor or heavy mesonheavy meson (( … …)) exchangeexchange

~1-2 fm 2 fm << 1 fm

AttractiveAttractiveRepulsiveRepulsivecorecore

Treatment of quark-gluon d.o.f.Treatment of quark-gluon d.o.f.will be inevitable!will be inevitable!

phenomenological approachphenomenological approach

““Nuclear Force from Lattice QCD” Nuclear Force from Lattice QCD” by N. Ishii, S. Aoki, T. Hatsuda, to be published in PRL this week.by N. Ishii, S. Aoki, T. Hatsuda, to be published in PRL this week.

First successful calculation of the nuclear force from First successful calculation of the nuclear force from quark-gluon d.o.f. quark-gluon d.o.f. ..

1.1. CalculateCalculate the (s-wave projected) NN wave the (s-wave projected) NN wave functionfunction using the Lattice QCD simulations.using the Lattice QCD simulations.

2.2. Obtain the central NN potential at each Obtain the central NN potential at each fixed fixed EE from the relation: from the relation:

Nature 445,157 (2007)Nature 445,157 (2007)

Several articles for this research Several articles for this research also appeared in newspapers also appeared in newspapers June 21June 21..

StrategyStrategy

( : s-wave projected NN w.f.; : reduced mass)( : s-wave projected NN w.f.; : reduced mass)

NN potential:NN potential:Review article by Prof. F. WilczekReview article by Prof. F. Wilczek

⇒ ⇒ Calculated using Calculated using “Blue Gene/L” at KEK“Blue Gene/L” at KEK

Lattice QCD captures the essential features of the NN potential Lattice QCD captures the essential features of the NN potential in all regionin all region!!

Lattice QCD result of the NN central potentialLattice QCD result of the NN central potential

Yukawa’s theory Yukawa’s theory (1(1 exchange) exchange)

Lattice QCDLattice QCD

Yukawa’s result (long distance)Yukawa’s result (long distance) Repulsive core (short distance) Repulsive core (short distance)

Yukawa’s result (long distance)Yukawa’s result (long distance) Repulsive core (short distance) Repulsive core (short distance)

pure Vcpure Vc

““effective” Vceffective” Vc= pure Vc + = pure Vc + VcVc

coupling effect coupling effect with with 33DD11 state. state.

Summary and PerspectivesSummary and Perspectives

Further improvements are needed for the quantitative estimations:Further improvements are needed for the quantitative estimations:-- 　　 Include the virtual pair contributionInclude the virtual pair contribution　 　 (non-quenched calculation)(non-quenched calculation)- Use the physical mass.- Use the physical mass.

Calculation of other components of the NN potential (LS, tensor etc.)Calculation of other components of the NN potential (LS, tensor etc.)

Investigation of Investigation of physical originphysical origin of the repulsive core. of the repulsive core.

Application to (“Application to (“predictionprediction” of) Nucleon-” of) Nucleon-HyperonHyperon1)1) and and HyperonHyperon--HyperonHyperon potentials.potentials.

1) 1) Hyperon = Baryon with “strangeness”Hyperon = Baryon with “strangeness”2) 2) J-PARC = Japan Proton Accelerator Research ComplexJ-PARC = Japan Proton Accelerator Research Complex

Closely related to the experimental research of hypernuclei at J-PARC2)

Which contributions and/or mechanisms Which contributions and/or mechanisms are responsible for the repulsive core?are responsible for the repulsive core?

⇔ ⇔ Interpretation of Interpretation of Yukawa’s theory:Yukawa’s theory: