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KEK Theory Center Workshop on Short-range Correlations and Tensor Structure at J-PARC September 25, 2009 Search for Direct Evidence of Tensor Interaction via ( p , d ) Reaction Hooi Jin, ONG Research Center for Nuclear Physics (RCNP) Osaka University. Tensor Interaction s in Atomic Nuclei.
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KEK Theory Center Workshop on Short-range Correlations and Tensor Structure at J-PARCSeptember 25, 2009Search for Direct Evidence of Tensor Interaction via (p,d) ReactionHooi Jin, ONGResearch Center for Nuclear Physics (RCNP)Osaka University
Tensor Interactions in Atomic Nuclei • Tensor interactions • Fundamental nuclear interactions that provide attractive force • Caused by pion exchange • Evidences of tensor interactions • Admixtures of D-wave in d, • Deviation of magnetic moments (of double-closed+1 nuclei) from the Schmidt values • Varying magic numbers in neutron-rich nuclei
Varying magic numbers in neutron-rich nuclei: one of the hot topics in nuclear physics • Possible role of tensor interactions inchanging the spin-orbit splitting... T. Otsuka et al, PRL95, 232502(2005)
But thus farthe “evidences” from nuclei heavier than d and aare indirect… Is “direct” evidence on the tensor interactions possible, experimentally? Tensor interactions: Intermediate range Mean field
Theoretical Momentum Distribution +N+N model W. Horiuchi and Y. Suzuki, PRC76, 024311(2007) pn pair (lines) pp pair (symbols) R. Schiavilla et al., PRL 98, 132501 (2007) T. Neff and H. Feldmeier, NPA713, 311(2003)
How to measure high momentum components? • (e,e'p), (e,e'pp), (e,e'pn), etc. • (p,2p), etc.
(p,d): Selective measurement of high momentum components + Measurement for quasi-free (p,pd) reaction Ep = 1GeV ‡ G. W. Bennett et al., PRL19, 387(1967) † K. Sekiguchi et al., PRL95, 162301(2004)
Subjects of Study: 12C and 16O • Measure the internal momentum, in particular, the High Momentum Component Selection Rule:J=0, L=S=2
Momentum Transfer • Cover momentum transfer at around 2 fm-1 (394 MeV/c) q=30° (p+12C -> d+11C) q=15° (p+12C) -> d+11C q=0° (p+12C) -> d+11C q=0° (p+12C) -> p+d+10B
Experiment Setup RCNP Grand RAIDEN d Θd Target p
Online Data: 16O Target States in 15O 16O(p,d) Ep=392 MeV Θd= 10°
Online Data: 12C Target 12C (p,d) Ep = 198 MeV Θd= 10° 12C (p,d) Ep= 392 MeV Θd = 20°
Online Data: (p,pd) channel • deuteron-proton coincidence events. 14N ground state Ep [MeV] Ed [MeV]
positive-parity states 11C Level scheme 0.0 3/2- 12C (p,d) Ep = 198 MeV Θd = 10° 12C (p,d) Ep = 295 MeV Θd = 10° 12C (p,d) Ep = 392 MeV Θd = 10°
positive-parity states 15O Level scheme 0.0 1/2- 16O (p,d) Ep = 198 MeV Θd = 10° 16O (p,d) Ep = 295 MeV Θd = 10° 16O (p,d) Ep = 392 MeV Θd = 10°
Summary • (p,d) and (p,pd) reactions on 12C and 16O targets have been measured with the Grand RAIDEN spectrometer at RCNP, Osaka Univ., using proton beam at energies 198, 295, 392 MeV. • Reaction involving high-momentum components has been observed.
Acknowledgment RCNP-E314 collaborators: RCNP I. Tanihata, A. Tamii, H. Okamura, M. Yosoi, T. Suzuki, K. Hirota, T. Naito, H. Matsubara, J. Zenihiro, Y. Yasuda, T. Adachi, Y. Tameshige, K. Suda, D. Ishikawa, H. Toki, T. Myo, Y. Ogawa Dep. of Phys., Osaka Univ. K. Matsuta, M. Fukuda, M. Mihara, D.Nishimura Miyazaki Univ. H. Sakaguchi Kyoto Univ. T. Kawabata Tsukuba Univ. A. Ozawa RIKEN Nishina Center K. Sekiguchi, K. Ikeda Nara Women’s Univ. M. Taniguchi
Acknowledgment Thank you very much for your attention! The organizers & KEK Theory Center Thank you very much for the invitation and financial support!