S-Y-05 S.H.Lee 1 1.Introduction 2.Theory survey 3.Charmed Pentaquark 4.Charmed Pentaquark from B decays Physics of Pentaquarks Su Houng Lee Yonsei Univ., Korea References: Y. Oh, H. Kim, Y. Kwon, S.H.Lee, : PRD, PLB’s S.H.Lee,k Y. Kwon : charmed pentaquark: in preparation

S-Y-05 S.H.Lee 2 Mass= 1.54 GeV, width <25 MeV, quark content= uudds 1. LEPS coll., Nakano et.al. PRL (2003) Introduction

S-Y-05 S.H.Lee 3 Verification 2. Verification by other group

S-Y-05 S.H.Lee 4 4. NA49 hep-ex/ found  *(1862) in  -  - (ddss u) with width< 18 MeV 3. CLAS finds no  ++ in K + P invariant mass   +(udud s) belongs to anti-decuplet

S-Y-05 S.H.Lee 5 I3I3 Y ud s 3 8  (1232)   (1532)  (1673) 10   N ?  ? 10 N(939)  (1190)   (1320) Baryon Reprsentation

S-Y-05 S.H.Lee 6 2. Could not confirm in subsequent experiments CDF, ZEUS, FOCUS 1. H1 collaboration (Deep Inelastic scattering) Heavy Pentaquarks (udud c)  c (3099) was found in D* p (uudd bar(c)) with width= MeV

S-Y-05 S.H.Lee 7 Experimental summary 1.  + controversial mass 1540 MeV> KN threshold (1435 MeV) 2.  c + controversial search was done with DN D*N final state (unbound) > 2800 MeV + 

S-Y-05 S.H.Lee 8 Theory review Soliton model + Quark model (biased and limited)

S-Y-05 S.H.Lee 9 1. SU(3) soliton 2. Quantizing the 8 angles, the Hamiltonian becomes I=J Hedghog Soliton model: original prediction (Diakanov, Petrov, Polyakov 97)

S-Y-05 S.H.Lee Diakanov Petrov Polyakov applied it to Anti decuplet which predicted mass= 1540, width=30 MeV 1. only SU(3) representations containing Y=N c B/3+S= N c /3 are allowed  moreover, the number of states 2I+1 at S=0 or Y= N c /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 3. With constraint coming from WZ term

S-Y-05 S.H.Lee 11 1.Karlinear, Lipkin diquark: C=3,F=3,S=0 triquark: C=3,F=6,S=1/2 Negative parity if all the quarks are in the lowest s-state Positive parity if a relative p wave But with this simple picture, it is not easy to understand small width Quark models

S-Y-05 S.H.Lee Jaffe, Wilczek Positive parity if a relative p wave L=0, S=1/2 L=1  J=1/2 and 3/2 (higher mass)

S-Y-05 S.H.Lee 13 But, a closer look revealed puzzles

S-Y-05 S.H.Lee Soliton picture is valid at large N_c: 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 N_c Quantization constraint requires 1.Octet 2.Decuplet 3.Anti decuplet (lowest representation containing s=1) Naive Solition model should fail (T. Cohen)

S-Y-05 S.H.Lee Mass splitting in large N_c: 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 naïve soliton quantization might be wrong

S-Y-05 S.H.Lee SU(2) soliton+ Kaon 2. Successful for hyperon (attractive (s qbar) ) but no pentaquark (repulsive q sbar) from WZ term Bound state approach for SU(3) soliton

S-Y-05 S.H.Lee 17 Summary of Solition approach for  + (ududs) 1. SU(3) Soliton Inconsistent application 2. Bound state approach No bound  + Can not be applied to heavy pentaquark  c (ududc) predict a bound heavy pentaquark  c (ududc) ie. mass is smaller than DN continuum Quark model also predict a bound heavy pentaquark  c (ududc) but no light pentaquark  +(ududs)

S-Y-05 S.H.Lee 18 Color spin interaction quark model

S-Y-05 S.H.Lee In QCD q-q are also attractive if in color anti-triplet channel. Quark-antiquark, or Quark-Quark attaction in QCD In perturbative QCD, 2 C B =C M This term is called color spin interaction

S-Y-05 S.H.Lee 20 Color spin interaction explains hadron spectrum In perturbative QCD 3 C B =C M = 635 MeV x ( m u ) 2 uu d Nucleon Color anti-triplet Spin index  sym  s=1

S-Y-05 S.H.Lee 21 Why there should be a heavy pentaquark 1. For Pentaquark L=0, S=1/2 L=1 2. If recombined into a D meson and Nucleon

S-Y-05 S.H.Lee 22 Summary of Theory for Pentaquark 1. The only consistent Soliton approach predict only heavy pentaquark 2. Constituent quark model also predict only heavy pentaquark may explain null result for light pentaquark Could not observe heavy pentaqurk from DN finla state because it might be bound Heavy pentaquark can only be observed from Weak decay May be from B factory? But do we have sufficient data and can one conclude anything if one tries?

S-Y-05 S.H.Lee 23 Anti-Charmed pentaquark from B decays

S-Y-05 S.H.Lee 24 Can we understand Baryonic decay mode of B + 1. Baryonic decay mode 2. Can we explain it using Dominant hadronic decay mode

S-Y-05 S.H.Lee 25 Baryonic decay mode of B + 1. Baryonic decay mode in hadronic language Coupling ? Form factor?

S-Y-05 S.H.Lee 26 Effective hadronic Lagrangian for heavy hadrons Photo production of open charm, W.Liu, C.M.Ko, SHLee (03) NPA

S-Y-05 S.H.Lee 27 Baryonic decay mode of B + 1. Baryonic decay mode in hadronic language 13.5 Obtain branching ratio of experimental measurement

S-Y-05 S.H.Lee 28 Pentaquark decay mode of B + Using hadronic interactions as before, we find the branching ratio to be Coupling=1 cc Branching ratio Total events

S-Y-05 S.H.Lee 29 Summary 1.Theory predicts no stable light pentaquark, but bound heavy pentaquark  might explain present null results 2. Baryonic decay mode of B+ can be sensibly estimated wit previously determined hadronic parameters 3.With present B+ data, can measure  c from  If found the first exotic ever, will tell us about QCD and dense matter  color superconductivity