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Relating holographic QCD models to hidden local symmetry models Property of X(3872) as a hadronic molecule with negative parity Masayasu Harada “New Hadons” Workshop 2010 @RIKEN (February 28, 2011) MH, S.Matsuzaki, K.Yamawaki, PRD82, 076010 (2010) MH and M. Rho,. arXiv:1010.1971 MH and Y.L. Ma, arXiv:1010.3607
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Relating Holographic QCD Models to Hidden Local Symmetry Models MH, S.Matsuzaki, K.Yamawaki, PRD82, 076010 (2010) MH and M. Rho,. arXiv:1010.1971
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◎ A possible V-A mixing term violates charge conjugation but conserves parity generates a mixing between transverse and A 1 ☆ Motivation : V-A mixing in dense baryonic matter M.H. and C.Sasaki, Phys. Rev. C 80, 054912 (2009) ◎ Dispersion relations meson A 1 meson
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☆ Determination of mixing strength C ◎ An estimation from dominance e-e- e+e+ A1 ρ + C ~ 0.1 GeV × (n B / n 0 ) n 0 : normal nuclear matter density ◎ An estimation in a holographic QCD (AdS/QCD) model ・ Infinite tower of vector mesons ( , ’, ”, …) in AdS/QCD models ・ These effects of infinite mesons can generate V-A mixing ・ This summation was done in an AdS/QCD model S.K.Domokos, J.A.Harvey, PRL99 (2007) a very rough estimation
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Can infinite tower of mesons contribute ? This is related to a long-standing problem of QCD not clearly understood: Why does the / meson dominance work well ? ・ In our works, MH, S.Matsuzaki, K.Yamawaki, PRD82, 076010 (2010) MH and M. Rho,. arXiv:1010.1971 we developed ways to relate holographic models to hidden local symmetry (HLS) models for pi and rho for handling infinite number of vector mesons.
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Example 1: EM form factor In Sakai-Sugimoto model infinite tower of mesons contributes. k=1 : meson k=2 : ’ meson k=3 : ” meson … = 1.31 + (-0.35) + (0.05) + (-0.01) + … ’’ ’’ ’’’ meson dominance ⇒ ; In the Hidden Local Symmetry EM form factor is parameterized as ・ Reduction of Sakai-Sugimoto model ⇒
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Example 1: EM form factor meson dominance 2 /dof = 226/53=4.3 ; SS model : 2 /dof = 147/53=2.8 best fit in the HLS : 2 /dof=81/51=1.6 Exp data : NA7], NPB277, 168 (1996) J-lab F(pi), PRL86, 1713(2001) J-lab F(pi), PRC75, 055205 (2007) J-lab F(pi)-2, PRL97, 192001 (2006) Infinite tower works well as the meson dominance ! MH, S.Matsuzaki, K.Yamawaki, PRD82, 076010 (2010) cf : MH, K.Yamawaki, Phys.Rept 381, 1 (2003)
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Example 2: transition form factor MH, S.Matsuzaki, K.Yamawaki, arXiv:1007.4715 cf : MH, K.Yamawaki, Phys.Rept 381, 1 (2003) best fit in the HLS : 2 /dof=24/30=0.8 Sakai-Sugimoto model : 2 /dof=45/31=1.5 meson dominance : 2 /dof=124/31=4.0
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Example 3: Proton EM form factor M.H. and M.Rho, arXiv:1010.1971 [hep-ph] meson dominance : 2 /dof=187 best fit in the HLS : 2 /dof=1.5 a = 4.55 ; z = 0.55 Violation of / meson dominance may indicate existence of the contributions from the higher resonances. Contribution from heavier vector mesons actually exists in several physical processes even in the low-energy region Sakai-Sugimoto: Hong-Rho-Yi-Yee model : 2 /dof=20.2 a = 3.01 ; z = -0.042
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Property of X(3872) as a Hadronic Molecule with Negative Parity MH and Y.L. Ma, arXiv:1010.3607
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X(3872) was first observed by Belle Collaboration: S. K. Choi et al. [Belle Collaboration], Phys. Rev. Lett.91, 262001 (2003) [arXiv: hep-ex/0309032]. Confirmed by the CDF, the D0 and the BaBar. Possible structures for X(3872) Hybrid state, F.E.Close ;B.A.Li,… Tetraquark state, J.Vijande, … Chrmonium-molecule mixing state, E.Braaten, Y.b.Dong, S.Takeuchi,... Molecular state with J PC = 1 ++, N.A.Tornqvist, Y.b.Dong, M.B.Voloshin, E.S.Swanson, Y.L. Ma, …… ☆ Observation of X(3872)
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☆ Recent Observation of X(3872) BaBar ; arXiv:1005.5190 The 3π mass distribution strongly favors P-wave ⇒ J PC = 2 -+ In our work, we regard X(3872) with J PC =2 -+ as DD* molecule, and study its properties.
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◎ Good point for J PC = 2 -+ Is explained naturally. ( no need of large isospin violation ) from phase space factor ⇒ X(3872) is dominantly I = 0 state. ◎ Bad point : J = 2 ⇒ DD* with L = 1 ・・・ L = 0 bound state ? We do not specify the origin of binding force, And just assume that X(3872) is L = 1 bound state.
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☆ Wave function of X(3872) as a DD* molecule ☆ Compositeness Condition = 0 m X input ⇒ A relation between φ and Λ X
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☆ Fit φ = 9 degree X = 99% ( I = 0 state) + 1% ( I = 1 state ) ☆ A typical prediction
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