1NuPECC meeting, 18 Nov. 2005

Few-body physics: Three-body force effects

Nasser Kalantar-Nayestanaki

Kernfysisch Versneller Instituut

Groningen

November 18, 2005

Few-body physics: Three-body force effects

Bound-state energies with GFMCC

ourt

esy

S. P

iepe

r, A

rgon

ne

(+3NF)

Few-body physics: Three-body force effects

• Study of the nucleon-nucleon interaction beyond the elastic scattering– Real-photon bremsstrahlung– Virtual-photon bremsstrahlung

• Study of three-body systems– Hadronic probes (three-body force effects) &– Electromagnetic probes &

• Study of strangeness in proton and deuteron

Few-body activities at KVI

Few-body physics: Three-body force effects

Three-Body Forces in Nature

Few-body physics: Three-body force effects

Three-Body Forces in Nature

Few-body physics: Three-body force effects

N

N

N

Three-body forces in Nuclear physics

3

1

3

1

2

2 jiij

i i

vm

H

Vvm

Hji

iji i

3

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Few-body physics: Three-body force effects

A three-body force is a force that does not exist in a system of two objects but appears in a system of three objects (three-body system like in Euler's three-body problem) or more. In physics, an intuitive example of a three-body force is the case of charged, metallic spheres: the charge distribution at the surface of two spheres placed close to each other will be modified, and thus the total force felt by a third sphere cannot be described by the sum of the forces from the two other spheres taken individually. The fundamental strong interaction seems to exhibits such behaviours. In particle physics, the interactions between the three quarks that compose baryons can be described in a diquark model which is equivalent to the hypothesis of a three-body force. There is growing evidence in the field of nuclear physics that three-body forces exist among the nucleons inside atomic nuclei (three-nucleon force).

Three-body forces and Wikipedia

As an analogy, if we identify bodies with humanbeings and forces with emotions, jealousy is agood example of three-body force: it is not felt as long as only two persons are acting, but it canshow up as soon as a third person enters into the scene. Retrieved from "http://en.wikipedia.org/wiki/Three-body_force"

Few-body physics: Three-body force effects

Total nd Cross sections

High precision data from Los Alamos

W.P. Abfalterer et al., PRL 81, 57 (1998)

nd scattering

np scattering

Only 2NF

Few-body physics: Three-body force effects

AGOR Facility

Detectors

SALAD1995-2002

BINA2004-???

BBS

PB

Few-body physics: Three-body force effects

pd elastic scattering cross sections

K. Ermisch et al.,

PRC 68, 054004 (2003),

PRC 71, 064004 (2005)

Few-body physics: Three-body force effects

pd elastic scattering cross sections

K. Ermisch et al.,

PRC 68, 054004 (2003),

PRC 71, 064004 (2005)

Few-body physics: Three-body force effects

pd elastic scattering cross sections

K. Ermisch et al.,

PRC 68, 054004 (2003),

PRC 71, 064004 (2005)

Few-body physics: Three-body force effects

pd elastic scattering cross sections

K. Ermisch et al.,

PRC 68, 054004 (2003),

PRC 71, 064004 (2005)

Few-body physics: Three-body force effects

pd elastic scattering cross sections

K. Ermisch et al.,

PRC 68, 054004 (2003),

PRC 71, 064004 (2005)

Few-body physics: Three-body force effects

pd elastic scattering cross sections

K. Ermisch et al.,

PRC 68, 054004 (2003),

PRC 71, 064004 (2005)

Few-body physics: Three-body force effects

pd elastic scattering cross sections

(the

ory

–dat

a)/d

ata

K. Ermisch et al.,

PRC 68, 054004 (2003),

PRC 71, 064004 (2005)

Few-body physics: Three-body force effects

pd elastic scattering cross sections

(the

ory

–dat

a)/d

ata

K. Ermisch et al.,

PRC 68, 054004 (2003),

PRC 71, 064004 (2005)

Few-body physics: Three-body force effects

Effect of 3NF as a function of Energy Ermisch et al.,

PRC71, 064004 (2005)

Few-body physics: Three-body force effects

Spin-Transfer Coefficients

Preliminary results

@ Ed = 180 MeV

Few-body physics: Three-body force effects

The break-up channel

p d p p n

St. Kistryn, PRC 68, 054004 (2003);&

PRC 72,044006 (2005)

Few-body physics: Three-body force effects

The break-up channel

2NF+3NF – 2NF

2NF+3NF

Bochum-Cracow Group(2NF=CDB, 3NF=TM’)Ep = 190 MeV

p d p p n

Few-body physics: Three-body force effects

The new 4 detector, BINA

BINA @ KVIBINA @ KVI

beam

~3

mete

rs

Big Instrument for Nuclear-polarization Analysis (BINA)

Few-body physics: Three-body force effects

The new 4 detector, BINA

150 phoswichScintillators=Target chamber

Forward scintillators (E-wall)

Thin scintillators forparticle identification

Wire chambers + analyzer

Few-body physics: Three-body force effects

The new 4 detector, BINA

Few-body physics: Three-body force effects

Summary & Outlook• The search for 3BF effects is taking place at

several laboratories.• At KVI, we have set up a comprehensive program

to study the three-body systems.• The situation for the three-body systems is like the

situation of NN of some 30 years ago!• The four-body systems is virgin territory at this

moment and needs desperate attention.

Few-body physics: Three-body force effects

Acknowledgements

H.R. Amir Ahmadi, J.C.S. Bacelar, R. Benard, A.M. van den Berg, R. Castelijns,M. Eslami-Kalantari, R. Bieber, K. Ermisch, E. Van Garderen, V.M. Hannen, M.N. Harakeh, M. de Huu, H. Huisman, M. Kis, H. Löhner, H. Mardanpour, A. Mehmandoost, J.G. Messchendorp, M. Mahjour-Shafiei, A. Ramazani, S. Schadmand, S. Shende, M. Volkerts, S.Y. van der Werf, H. Wörtche

+ KVI theory group

+ Cracow Experimental Group

+ Theoretical support from Bochum-Cracow + Hannover group

+ TAPS collaboration