Introduction Theory survey Quark model and Exotics Exotics from RHIC

Exotics from Heavy Ion Collision Su Houng Lee Yonsei Univ., Korea • Introduction • Theory survey • Quark model and Exotics • Exotics from RHIC References: H. Kim, Y. Oh, S.H.Lee, PLB 595 (04) 293: Y. Sarac, H.Kim, S.H.Lee, PRD 73 (06) 014009 S.H.Lee, Y. Kown, Y. Kown, PRL 96 (06) 102001

Exotics • Hadrons that can not be explained by quark-antiquark, or 3 quarks • That are bound by strong interaction • Reasons for its search are similar to that for superheavy Element in low energy nuclear Physics

Introduction 1. LEPS coll., Nakano et.al. PRL 91 012002 (2003) Mass= 1.54 GeV , width <25 MeV , quark content= uudds

New Baryon Repersentation ? Y d u I3 3 s • D(1232) • *(1383) X*(1532) W(1673) • (1540) X(1862) 10 N(939) S(1190) L(1115) X(1320) N ? S ? 8 10

Positive results Negative results Recent CLAS experiments find no Q+ in g+d or g+p  Give up, more experiment or theoretical guideline?

Theory review Soliton model + Quark model (biased and limited)

Soliton model: original prediction (Diakanov, Petrov, Polyakov 97) 1. SU(3) soliton I=J Hedghog 2. Quantizing the 8 angles, the Hamiltonian becomes

3. With constraint coming from WZ term 1. only SU(3) representations containing Y=1 are allowed moreover, the number of states 2I+1 at S=0 or Y= Nc/3 must determine the spin of the representation through 2J+1 because I=J in the SU(2) soliton  one spin state for given representation 4. Diakanov Petrov Polyakov applied it toAnti-decuplet which predicted MQ= 1540, GQ=30 MeV

But! Naive Solition model should fail (T. Cohen) 1. Soliton picture is valid at large Nc: Semi-classical quantization is valid for slow rotation: ie. Valid for describing excitations of order 1/N_c, so that it does not mix and breakdown with vibrational modes of order 1 2. Lowest representation SU(3)f (p,q)at large Nc Quantization constraint requires • Octet • Decuplet • Anti decuplet • (lowest representation containing s=1)

3. Mass splitting in large Nc: Anit decuplet octet mass splitting is mixes with vibrational mode and inconsistent with original assumption and has undetermined correction of same order  Rotation is too fast and may couple to vibrational modes, which might be important to excite q qbar mode, hence describing anti decuplet state with naive soliton quantization might be wrong

Summary of Solition approach for Q+ (ududs) 1. SU(3) Soliton Inconsistent application 2. Bound state approach No bound Q+ Original prediction has ambiguity. Wait for more experiments from Srping 8 However, soliton approach predict a stable heavy pentaquark Qc(ududc) (N. Scocolla, Y.Oh, B. Park, D.P.Min (94)) ie. mass is smaller than DN continuum

Quark Model Light pentaquark (udud s) vs Heavy pentaquark (udud c)

Possible Quark structure of a pentaquark Strong diquark correlation Karlinear, Lipkin model u d diquark: C=3,F=3,S=0 triquark: C=3,F=6,S=1/2 s u d Jaffe, Wilczek model u d 2 diquark: C=3,F=3,S=0 relative p wave s d u

Color Spin Interaction in QCD 1. In QCD q-q are also attractive if in color anti-triplet channel. In perturbative QCD, 2CB=CM This term is called color spin interaction

Color spin interaction explains hadron spectrum u u d Nucleon Baryon Mass difference Meson Mass difference Works very well with 3CB=CM = constant

Why there should be a heavy pentaquark 1. For a charmed Pentaquark c 3. If recombined into a D-meson and a Nucleon c 1. For a Pentaquark u u s d d 2. If recombined into a Kaon and a Nucleon u u d s d

Other possible states - Tetraquark 1. For a Tetraquark 2. For the meson and meson u d A u B A B d DD- BB-

Experimental search for Heavy Pentaquarks (udud c) 1. H1 collaboration (Deep Inelastic scattering) Qc(3099) was found in D* p (uudd bar(c)) with width= 12+-3 MeV 2. Could not confirm in subsequent experiments CDF, ZEUS, FOCUS

Experimental search for Heavy Pentaquarks (udud c) 1. H1 collaboration in 2004 (Deep Inelastic scattering) Qc(3099) was found in D* p with width= 12+-3 MeV D* p (2950) D p (2810) 2. Could not confirm in subsequent experiments CDF, ZEUS, FOCUS in 2004, 2005 3. No systematic search was made below DN threshold or in RHIC?

Anti-Charmed Pentaquark from B decays

Baryonic decay mode of B+ decay in hadronic language Larger By Nc

Pentaquark decay mode of B+ Weak decay Branching ratio is 0.092 Qc lower limit in B-factory Can search for it in Belle S.H.Lee. Y. Kown. Y. Kwon , PRL (06) Using pevious fit, we find the branching ratio to be 14.4x10-7 gDpL x gKpQ/gKpL

RHIC might give an answer Anticharmed pentaquark (DN) Heavy Tetraquark (DD)

Why hadronic physics from RHIC? In Au+Au at 200 GeV (statistical model by Randrup) QGP N+K u u s u u d d d s d Q+ u u s d d L=1

STAR collaboration?

Possible exotics and their decay modes RHIC might be an excellent laboratory to search for exotics

Summary • While controvery exist over light pentaquark, Many Theories consistently predict bound heavy pentaquark 2. Quark model also predict metastable tetraquark • RHIC can be a very useful exotic factory (Prof. Huang)  If found the first exotic ever, will tell us about QCD and dense matter  color superconductivity

References • Experiments • T. Nakano , Phys. Rev. Lett. 91 (03) 012002. • K.~H.~Hicks, Prog. Part. Nucl. Phys. 55 (05) 647. • Skyrme model controversy • T.D.Cohen, Phys. Lett. B 581 (04) 175 • H. Walliser and H. Weigel, Eur. Phys. J. A 26 (05) 361. • D.Diakonov, V.Petrov and M.V.Polyakov, Z. Phys.A 359 (97) 305 • Theory • H. J. Lipkin, Phys. Lett. B 195 (87) 484. • Fl. Stancu, Phys. Rev. D 58 (98) 111501. • D. O. Riska, N. N. Scoccola, Phys. Lett. B 299 (93) 338. • Y.Oh, B.Y. Park, D.P. Min, Phys. Lett. B 331 (94) 362. Phys. Rev. D 50 (94) 3350. • R.L.Jaffe, F.Wilczek, Phys. Rev.Lett. 91(2003) 232003. • present work • H. Kim, Y. Oh, S.H.Lee, PLB 595 (04) 293: • Y. Sarac, H.Kim, S.H.Lee, PRD 73 (06) 014009 • S.H.Lee, Y. Kown, Y. Kown, PRL 96 (06) 102001

Introduction Theory survey Quark model and Exotics Exotics from RHIC