强作用物质性质研讨会, 遵义, Before and after the discovery of d* dibaryon Hongxia Huang, Jialun Ping Nanjing Normal University Fan Wang Nanjing University

强作用物质性质研讨会, 遵义, Outline  Introduction  Quark cluster model approach of NN interaction  Quark delocalization color screening model  Comprehensive studies of d* dibaryon  The discovery of d* dibaryon  After the discovery of d* dibaryon

强作用物质性质研讨会, 遵义, Introduction Similarity of nuclear force and molecular force call for an understanding electron percolation quark delocalization

强作用物质性质研讨会, 遵义,  Molecular force is due to atom mutual polarization caused by electron delocalization.  Meson exchange between point nucleon picture is totally different from the mechanism of molecular bond.  Color singlet quark model of nucleon provide a possibility to understand the similarity of nuclear force and molecular force.

强作用物质性质研讨会, 遵义, Quark cluster model approach of NN interaction  1975 we did SU(4) analysis of charm quark states with Lu Tan et al.  1976 we did resonating group method (RGM) nuclear data calculation.  I extended quark model for single hadron to two-baryon developed the quark cluster model to calculate NN interaction with RGM in  Checked with C.N. Yang in  1978 Lushan conference I reported this quark cluster model approach of NN interaction.  Oka and Yazaki first RGM calculation cited our 1980 Bologna international conference contribution. Faessler brought our paper to Beijing winter school.

强作用物质性质研讨会, 遵义,  1984 I studied 4-quark states with C.W.Wong at UCLA Multi-quark strings, Nuovo Cim. A86(1985)283.  1986 I studied SU(3) 6-quark states with T. Goldman at LANL. Strangeness-3 dibaryons, PRL 59(1987)627. An ‘inevitable’ non-strange dibaryon, PRC39(1989)1889. Why d* is inevitable? 1.Quark delocalization reduce the kinetic energy of quark and provide effective attraction for dibaryon. 2.Color magnetic interaction provide repulsion (attraction) for spin triplet (singlet) quark pair for single baryon states, which provide the repulsive core for Octet dibaryons and effective attraction for decuplet dibaryons.

强作用物质性质研讨会, 遵义, Quark delocalization color screening model  We have to develop a quantitative model to check the above qualitative model predictions. This model must be able to describe the vast NN interaction data, including both bound and scattering data. Then apply to dibaryon states.  1988 I spent 9 months to make a transit-world academic trip to meet experts in this field almost all over the world, including T.D.Lee, G.t’Hoft, E. Lomon, N.Isgur, T.E.O.Ericson, J. de Swart, M. Locher, Vin Mauo, Chemtob, Holinder, J.Speth, Y.Simonov, V.Neuydachin and others.

强作用物质性质研讨会, 遵义,  After coming back in China, I collecting informations what I got in this round-world trip to develop a quark model for multiquark systems.  Unfortunately I had been partially employed in the education department so this project took quite a long time. Finally collaborating with G.H. Hu and L.J. Teng to complete the numerical calculation. Quark delocalization, color screening and nuclear intermediate range attraction, PRL 69(1992)2901.

强作用物质性质研讨会, 遵义,  Quark delocalization: the parameter εis determined by system dynamics 。  The main advantage of QDCSM : the delocalization parameter is determined through its own dynamics, so multi-quark system choose its most favorable configuration in the course of interaction. For example in the NN scattering process, the two nucleons vary from two independent spherical nucleons through polarized two nucleons, merge into a peanut finally a 6- quark spherical ball.

强作用物质性质研讨会, 遵义,  Color screening ： qq interaction: inside baryon outside baryon different the color structure is taken into considerationcolor structure three gluons exchange  0 (inside baryon) = 0 (outside baryons)

强作用物质性质研讨会, 遵义,  We did a hidden color channel coupling calculation with normal color confinement and obtained the same quality fit to the deuteron and NN scattering data, so the color screening might be an effective description of hidden color channel effect. Hidden color channel effect in NN scattering, PRC 84(2011)  We also did a comparative study with QDCSM and CHQM use exact same model parameters but replace the sigma meson in CHQM with color screening and quark delocalization in QDCSM and proved these two models gave quantitatively the same NN interaction. An alternative approach for nuclear intermediate range attraction, PRC 76(2007)

强作用物质性质研讨会, 遵义, QDCSM vs ChQM  PRC 76(2007)

强作用物质性质研讨会, 遵义, Comprehensive studies of d* dibaryon  In order to do comprehensive calculation of multi-quark system especially dibaryons, we develop a systematic group theory method. An extension of the fractional parentage expansion to nonrelativistic and relativistic SU^f(3) dibaryon calculation, PRC 51(1995)1648. in collaboration with J.L.ping

强作用物质性质研讨会, 遵义,  We use three quark model to check the reliability of these model calculation, QDCSM, ChQM, Relativistic QM, also Zhang et al ChQM in cases.  First Adiabatic calculation to do an overall search in SU(3) flavor world, then single channel dynamical calculation for special interesting channels, and finally multi- channel coupling calculation to study the baryon and dibaryon resonances.

强作用物质性质研讨会, 遵义,  Comprehensive studies of d* Quark delocalization color screening model: PRC51 (1995) 3411; Relativistic QM: Ping, Mod. Phys. Lett., A13 (1998) 59; QDCSM d* decay: NPA688 (2001) 871; Extended QDCSM d* decay: PRC65 (2002) ; d* production and decay: PRC57 (1998) 1962; three-body decay of d*: PRC58 (1998) 2414; d* decay: PRC70 (2004) ;  NN scattering and d*: QDCSM and ChQM: PRC 79 (2009)  Symmetry analysis: Dyson and Xuong, PRL13 (1964) 815; Bashkanov, Brodsky and Clement: PLB727 (2013) 438; HX Huang, JL Ping & F Wang: PRC89 (2014)

强作用物质性质研讨会, 遵义, Proposals for d* experimental searching  In 1990, LAMPF: four proposed experiments in A better dibaryon than H particle  In 1997, TRIUMF: Search for the \Delta - \Delta Dibaryon S. Yen, … (TRIUMF), T. Goldman (LANL), C.W. Wong, … (UCLA), T.E. Drake, … (U.Toronto), F. Wang, … (Nanjing U.), Y. Ye, … (Peking U.), W.R. Falk (U.Manitoba), C. Rangacharyulu (U.Saskatchewan), E.G. Auld, … (UBC), G.V. O'Rielly, … (UNBC), T.G. Walton (Cariboo U. College), A.K. Opper (Ohio U.), R.D. Bent (Indiana U.), I.I. Strakovsky (Virginia Tech), D. Frekers, M. Hartig (Muenster U.)

强作用物质性质研讨会, 遵义, d* in QDCSM  d* (IJ P =03 + ) as a resonance in NN scattering  Mass 2270—2400 MeV  Γ NN = 14 –17 MeV  Γ inel = MeV  Total width Γ= 50 – 158 MeV  agrees with WASA-at-COSY measurements.

强作用物质性质研讨会, 遵义, Other dibaryons in QDCSM  D 12 (IJ P =12 + ): M=2168 MeV, Γ=121 MeV Experimental signal: M=2148 MeV, Γ=118 MeV  NΩ(IJ P =1/2 2 + ): M= MeV, Γ< 1 MeV  ΩΩ(IJ P =00 + ): M ~ 3300 MeV

强作用物质性质研讨会, 遵义, The discovery of d* dibaryon  baryon number = 2 “d* (IJ P =03 + ) ”: M=2380 MeV, Γ=70 MeV reported continuously by WASA-at- COSY collaboration PRL 102, (2009); PRL 106, (2011); PLB 721, 229 (2013); PRL 112, (2014); PRC 88, (2013)

强作用物质性质研讨会, 遵义, WASA-at-COSY measurements

强作用物质性质研讨会, 遵义,

CERN Courier 2011 

强作用物质性质研讨会, 遵义, CERN Courier 2014 

强作用物质性质研讨会, 遵义, After thr discovery of d* dibaryon  Dibaryon had been discovered and disappeared few times, so this community is very cautious on the new discovery.  We must have an independent check of the existence of d* dibaryon.  WASA-at-COSY collaboration plan to use their collected data to search the company dibaryon IJP=30+.

强作用物质性质研讨会, 遵义,  They also plan to use Meinz electron beam to do ed->ed* production measurements.  Y.J. Mao group started an analysis of DESY ed scattering data.  H.Y.Gao plan to propose to do ed->ed* at Jlab.  H.Z. Huang group started STAR data analysis to search N\Omega resonance.  Y.G Ma group started the \Lambda\Ksi invariant mass analysis and 3 days ago we discussed at Shanghai to extend to analyse the \Lambda\Ksi and p\Omega correlation.

强作用物质性质研讨会, 遵义,  Theoretical study of the properties of d* especially the decay width. Our understanding is because our Feshbach resonance channel coupling calculation obtained almost the right resonance width so it is produced through such a process, but the other decay widths is smaller than a naïve bound \delta width estimate, the binding energy is large (~80 MeV), the size is small (~1 fm), so it should be a compact 6 quark state. J.L. Ping will give a critical analysis about the large hidden component assumption.

强作用物质性质研讨会, 遵义,  A lesson Strong scattering channel coupling to an otherwise bound hadron states might change the energy drastically. IJP=01+ NN scattering channel coupling push the otherwise deep bound dibaryon to Continuum(push up 300MeV). \pi N scattering channel coupling lower the 1.5 GeV \Delta to 1.2 GeV.

强作用物质性质研讨会, 遵义,  To do quark model or lattice hadron spectroscopy calculation, to study the near threshold resonance have to taking this channel coupling effect into account.

强作用物质性质研讨会, 遵义, Dynamical symmetry  Gell-Mann-Zweig quark model: classification system -- Eightfold Way SU(3) flavor symmetry  Ω  IBM: Arima and Iachello  FDSM: D.H. Feng, C.L. Wu and J.Q. Chen

强作用物质性质研讨会, 遵义,  Dynamical symmetry: H: Hamiltonian of a system can be expressed in terms of C,C 1,C 2,……: Casimir operators or class operators of group chain Eigenenergy of the system can be obtained directly from the eigen value of these operators

强作用物质性质研讨会, 遵义, Group chain of quark model Hadron ground states: orbital: U x (1) color: SU c (3) flavor: SU f (3) spin: SU σ (2) Group chain:

强作用物质性质研讨会, 遵义, Dynamical symmetry applied to quark model  Color: singlet, [c] fixed  Gursey-Radicati mass formula (PRL13(1964)173)

强作用物质性质研讨会, 遵义,  Parameters the masses of baryons A= B= C= D= (unit: MeV)

强作用物质性质研讨会, 遵义, Baryon: qqq  Group chain:  [μ]=[3], dim=56  [μ]=[ f ] x [ σ]: [21] x [21], [3] x [3] octet decuplet M 0 = MINUIT  err

强作用物质性质研讨会, 遵义,

NΛΣΞΔΣ*Σ*Ξ*Ξ*Ω Y I½01½3/21½0 J½½½½ [f][21] [3] theo err exp

强作用物质性质研讨会, 遵义, Dibaryon: qqqqqq  Group chain:  [μ]=[33], dim=490  [μ]=[ f ] x [ σ]: [6]x[33], [51]x[42], [42]x[51], [42]x[33] [411]x[42], [33]x[6], [33]x[42], [321]x[51] [321]x[42], [222]x[33]

强作用物质性质研讨会, 遵义,  [f]=[6] dim=28

强作用物质性质研讨会, 遵义,  [f]=[51] dim=35

强作用物质性质研讨会, 遵义,  [f]=[42] dim=27

强作用物质性质研讨会, 遵义,  [f]=[411] dim=10 [f]=[33] dim=10

强作用物质性质研讨会, 遵义,  [f]=[321] dim=8  [f]=[222] dim=1

强作用物质性质研讨会, 遵义, D 01 D 10 D 03 D 30 D 12 NΩNΩΩΩH Y I01031½00 J [f][33][42][33][6][42][321][6][222] theo err exp ?2357??2148????

强作用物质性质研讨会, 遵义, Penta-quark (5-quark)  2003, Θ + : B=1, S=+1 minimum quark content: uudds  Roper resonance: N*(1440)

强作用物质性质研讨会, 遵义,  Two steps: 1.4-quark coupling Group chain [μ]=[31]  [f 4 ] x [σ 4 ]=[4]x[31], [31]x[4],[31]x[31],[31]x[22] [22]x[31], [211]x[31],[211]x[22] 2. 4q-q coupling: [f]x[σ]=[51]x[41],[51]x[32],[42]x[5],[42]x[41],[42]x[32], [411]x[5],[411]x[41],[411]x[32],[33]x[41], [33]x[32], [321]x[5],[321]x[41],[321]x[32],[222]x[41],[222]x[32]

强作用物质性质研讨会, 遵义,  [f]=[51] dim=35 J=3/2,1/2

强作用物质性质研讨会, 遵义,  [f]=[42] dim=27 J=5/2, 3/2, 1/2

强作用物质性质研讨会, 遵义,  [f]=[33] dim=10 J=3/2, 1/2

强作用物质性质研讨会, 遵义, Θ+Θ+ Ξ 3/2 Θ+Θ+ Ω1Ω1 ΓΠΘ2Θ2 Ω1Ω1 Y I03/ J½ 5/2½3/25/2½3/2 [f][33] [42] [51] Theo Err exp ????????

强作用物质性质研讨会, 遵义, NN scattering

强作用物质性质研讨会, 遵义, resonance

强作用物质性质研讨会, 遵义,

deuteron

强作用物质性质研讨会, 遵义, QDCSM vs ChQM  PRC 76(2007)

强作用物质性质研讨会, 遵义,

Hidden color channel effects?  PRC 84 (2011)  Color singlet-color singlet: k=1  Color singlet-color octet: k≠1

强作用物质性质研讨会, 遵义,

Tetra-baryon ： 12-quark system  4 He: (nnpp) (u↑u ↑ u ↑ u↓u↓u↓d↑d ↑ d ↑ d↓d↓d↓)  4n: (nnnn) (d↑d ↑ d ↑ d↓d↓d↓--d↑d ↑ d ↑ d↓d↓d↓)  F.M.Marques, et al., PRC65(2002) Be  10 Be + 4 n

强作用物质性质研讨会, 遵义,  Hadron level: no tetraneutron multibody interaction -- > bound state ?  Quark level: 12-quark system preliminary work: effective potential V(a) = E (a) - E(∞)

强作用物质性质研讨会, 遵义,  Constructing the wavefunctions 1.3-quark wavefunctions: 2.6-quark wavefunctions: S 6 ﬤ S 3 xS 3 coset decomposition

强作用物质性质研讨会, 遵义, quark wavefunctions: S 12 ﬤ S 6 x S 6 coset decomposition numbers of coset representatives: 12!/(6!6!) = 924

强作用物质性质研讨会, 遵义,  Chiral quark model

强作用物质性质研讨会, 遵义,  Results:

强作用物质性质研讨会, 遵义,

nnΛΛ

强作用物质性质研讨会, 遵义, Summary  QDCSM describes NN scattering, deuteron properties well  QDCSM can explain the similarity between molecular force and nuclear force  Dynamical symmetry analysis predicted the existence of d*  The d* calculation in QDCSM is confirmed by WASA-at- COSY collaboration’s results.  Tetra-baryon will provide an example for extending quark model to multi-hadron molecules. Thanks!!!