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On a possibility of baryonic exotica
Michał Praszałowicz in collaboration with M.V. Polyakov (Bochum) H.-C. Kim (Incheon)
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2003 LEPS Collaboration
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July 2003
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exotic quantum numbers very small width: a few MeV
July 2003 exotic quantum numbers small mass: 1.5 GeV very small width: a few MeV
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Michal Praszalowicz, Krakow
Quark Model (uudds): 4 x ~ 1900 MeV ~ MeV pentaquark: strangeness +1 + (2s) - (s) = 150 MeV spin 1/2 parity Michal Praszalowicz, Krakow
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Michal Praszalowicz, Krakow
Chiral Soliton Models Biedenharn, Dothan (1984): 10-8 ~ 600 MeV Skyrme model MP (1987): M= 1535 MeV Skyrme model in model independent approach, second order Diakonov, Petrov, Polyakov (1997): QM - model independent approach, 1/Nc corrections M= 1530 MeV small width < 15 MeV ! In Chiral Soliton Models quark-antiquark pairs are added as chiral excitations of low mass (pion is massless!) rather than as two constituent (i.e. heavy) quarks. Michal Praszalowicz, Krakow
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Michal Praszalowicz, Krakow
Soliton Quark Model (uudds): 4 x ~ 1900 MeV MeV ~ 400 MeV a few MeV pentaquark: strangeness +1 + (2s) - (s) = 150 MeV 350 spin 1/2 parity + Michal Praszalowicz, Krakow
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What is the experimental status of light pentaquarks today?
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LEPS and various conference proceedings e.g. T. Nakano MENU 2016
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DIANA
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dissidents from CLAS
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disicalaimer from CLAS
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What is the experimental status of light pentaquarks today?
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NA 49
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What is the experimental status of light pentaquarks today?
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Pentanucleon? D. Werthmuller et al. [A2 Collaboration]
Phys. Rev. Lett. 111 (2013) 23, Eur. Phys. J. A 49 (2013) 154 Phys. Rev. Rev. C 90 (2014) Michał Praszałowicz
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Pentanucleon? M.V. Polyakov and A. Rathke, On photoexcitation of baryon anti-decuplet Eur. Phys. J. A 18 (2003) 691 natural (but not the only one) explanation if N* is a pentaquark
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QCD: quarks and gluons many quark nonlocal interactions
integrate out gluons many quark nonlocal interactions Lagrangian chirally symmetric approximation: manyq, nonl q, local Nambu Jona Lasinio model spontaneous chiral symmetry breaking semibosonization: qqqq qq Chiral Quark Model M. Praszałowicz
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Chiral Quark Soliton Model
QCD vacuum:
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Chiral Quark Soliton Model
QCD vacuum:
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Chiral Quark Soliton Model
chiral symmetry breaking: chirally inv. manyquark int.
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Chiral Quark Soliton Model
adding vlence quarks: chirally inv. manyquark int.
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Chiral Quark Soliton Model
“classical” baryon: chirally inv. manyquark int. soliton configuration no quantum numbers except B
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Chiral Quark Soliton Model
“classical” baryon: = Nc × chiral symmetry breaking chirally inv. manyquark int. soliton configuration no quantum numbers except B color factorizes!
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Chiral Quark Soliton Model
baryon: chirally inv. manyquark int. soliton configuration no quantum numbers except B rotation generates flavor and spin
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Mass formula first order perturbation in the strange quark mass
O(1) corrections to Mcl do not allow for absolute mass predictions octet-decuplet splitting exotic-nonexotic splittings known ? first order perturbation in the strange quark mass and in Nc: x P.O. Mazur, M.A. Nowak, MP, Phys. Lett. 147B (1984) 137 E. Guadagnini, Nucl. Phys. B236 (1984) 35 S. Jain, S.R. Wadia, Nucl. Phys. B258 (1985) 713
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Allowed states
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Successful Phenomenology
Ch.V. Christov et al. Prog. Part. Nucl. Phys. 37 (1996) 91 Successful Phenomenology In a ”model independent” approach one can get both good fits to the existing data (including very narrow light pentaquark Θ+) one can fix all necessary model parameters: M, I1, I2, α, β, γ
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Successful Phenomenology
Ch.V. Christov et al. Prog. Part. Nucl. Phys. 37 (1996) 91 Successful Phenomenology In a ”model independent” approach one can get both good fits to the existing data (including very narrow light pentaquark Θ+) one can fix all necessary model parameters: M, I1, I2, α, β, γ but also one can recover the NRQM result in a special limit NRQM limit = = squeezing the soliton to zero size MP, A. Blotz, K. Goeke Phys. Lett. B354 (1995) 415
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NRQM Limit energy is calculated with respect to the vacuum:
Diakonov, Petrov, Polyakov, Z.Phys A359 (97) 305 MP, A.Blotz K.Goeke, Phys.Lett.B354: ,1995 energy is calculated with respect to the vacuum:
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NRQM Limit energy is calculated with respect to the vacuum:
Diakonov, Petrov, Polyakov, Z.Phys A359 (97) 305 MP, A.Blotz K.Goeke, Phys.Lett.B354: ,1995 energy is calculated with respect to the vacuum:
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NRQM Limit energy is calculated with respect to the vacuum:
Diakonov, Petrov, Polyakov, Z.Phys A359 (97) 305 MP, A.Blotz K.Goeke, Phys.Lett.B354: ,1995 energy is calculated with respect to the vacuum: in the NRQM limit only valence level contributes
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NRQM Limit energy is calculated with respect to the vacuum:
Diakonov, Petrov, Polyakov, Z.Phys A359 (97) 305 MP, A.Blotz K.Goeke, Phys.Lett.B354: ,1995 energy is calculated with respect to the vacuum: in the NRQM limit only valence level contributes
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NRQM Limit pentaquark width = 0 ! energy is calculated
Diakonov, Petrov, Polyakov, Z.Phys A359 (97) 305 MP, A.Blotz K.Goeke, Phys.Lett.B354: ,1995 energy is calculated with respect to the vacuum: pentaquark width = 0 ! in the NRQM limit only valence level contributes
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Soliton with Nc− 1 quarks
if Nc is large, Nc- 1 is also large and one can use the same mean field arguments (Nc−1) × color factorizes! plus one heavy quark G.S. Yang, H.C. Kim, M.V. Polyakov, MP Phys. Rev. D94 (2016)
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Allowed SU(3) irreps. = (Nc−1)/3
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Heavy Baryons: soliton + heavy Q
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Splittings inside multiplets
= SL one has to add h.f. interaction
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Splittings inside multiplets
Equal splittings within multiplets follow from Eckhart-Wigner theorem (GMO relations)
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Splittings inside multiplets
Equal splittings within multiplets follow from Eckhart-Wigner theorem (GMO relations) however the relation between the deltas does not follow from Eckhart-Wigner theorem
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Splittings inside multiplets
from the fits to the light sector we get: (exp.: 178 MeV) 13% (exp.: 121 MeV)
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Splittings inside multiplets
Successful phenomenology from the fits to the light sector we get: G.S. Yang, H.C. Kim, M.V. Polyakov, MP Phys. Rev. D94 (2016) (exp.: 178 MeV) 13% (exp.: 121 MeV)
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Rotational excitations: heavy pentaquarks
2/3 H.C. Kim, M.V. Plyakov, MP arXiv: [hep-ph]
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Rotational excitations: heavy pentaquarks
soliton in 15 (quatroquark) (spin 1 < spin 0) + heavy quark: 1/2 + 3/2 2/3 H.C. Kim, M.V. Plyakov, MP arXiv: [hep-ph]
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Rotational excitations: heavy pentaquarks
soliton in 15 (quatroquark) (spin 1 < spin 0) + heavy quark: 1/2 + 3/2 2/3 H.C. Kim, M.V. Plyakov, MP arXiv: [hep-ph]
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Decay constants H.C. Kim, M.V. Plyakov, MP arXiv: [hep-ph]
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Decay constants Expectations: some decays will be suppressed
In NRQM limit: Expectations: some decays will be suppressed H.C. Kim, M.V. Plyakov, MP arXiv: [hep-ph]
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Quark excitations: non-exotic heavy baryons
V. Petrov, Acta Phys. Pol. B47 (2016) 59
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Quark excitations: non-exotic heavy baryons
Rotations generate quantum numbers
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One K=1 quark excited solitons
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3bar excited heavy baryons
add heavy quark total spin 1/2 and 3/2
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3bar excited heavy baryons
experimentally: add heavy quark total spin 1/2 and 3/2 hyprfine splitting different from the ground state
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sextet excited baryons
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sextet excited baryons
excited Omega_Q spectrum, 5 states
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5 states!
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Five very narrow resonances, unknown quantum numbers
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Scenario 1: all LHCb Omega’s are sextet states
violates constraints:
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Scenario 1: all LHCb Omega’s are sextet states
violates constraints: similar problem in the quark models
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Scenario 2 force sextet constraints
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heavy states above Ξ + D threshold, large p.s. also to Ωc+ π, can be
very wide =24
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Two narrow heavy states states (1 MeV) above inerpreted as Ξ + D
pentaquarks heavy states above Ξ + D threshold, large p.s. also to Ωc+ π, can be very wide =24
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Consequences Omega’s form isospin triplet,
easy to check experimentally
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Consequences rich structure - many new states,
also in the case of b baryons Omega’s form isospin triplet, easy to check experimentally
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Conclusions naive QM admits heavy pentaquarks with naturally large width soliton models ARE quark models successful phenomenology in the light baryon sector in soliton models pentaquarks are naturally light in NR limit no decay of antidecuplet to ocet (!) LEPS and DIANA results stand null results put bounds on prod. mechanism rather than exclude 5q narrow structure in eta photoproduction on n – signature of 5q? confirmation or refutation of NA49 result needed heavy baryons can be desribed in terms of Nc-1 quark soliton two types of excitations: rotations: 15-bar (exotic) quark excitations (regular) two of the LHCb Omega_c states may be interpreted as 5q
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Backup slides
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Prediction for Ω*b Ω*c = 2764.5 ± 3.1 MeV (2765.9 ± 2.0)
model – independent relation: satisfied for charm: Ω*c = ± 3.1 MeV ( ± 2.0)
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Ω*b = 6079.8 ± 2.3 MeV (to be confirmed)
Prediction for Ω*b model – independent relation: satisfied for charm: Ω*c = ± 3.1 MeV ( ± 2.0) Ω*b = ± 2.3 MeV (to be confirmed)
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How narrow they are? Assume p-wave decay and extract coupling from Delta decay
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ground state L = 0 spin 1/2 h.f. splitting 70 MeV spin 3/2 ss -diquark
heavy quark h.f. splitting 70 MeV ss -diquark spin 3/2 heavy quark
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spin 1/2, 3/2 spin 1/2, 3/2, 5/2 excited state L = 1 ss -diquark
heavy quark ss -diquark spin 1/2, 3/2, 5/2 heavy quark
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FIVE STATES as in LHCb ! spin 1/2, 3/2 spin 1/2, 3/2, 5/2
excited state L = 1 ss -diquark spin 1/2, 3/2 heavy quark FIVE STATES as in LHCb ! ss -diquark spin 1/2, 3/2, 5/2 heavy quark
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Very narrow excited Ωc baryons
Marek Karliner, Jonathan L. Rosner, e-Print: arXiv: take general spin potential, try sensible parameters, only 3 parameters: a2 + c, a1, b. does not work Six Ω0c states discovered by LHCb as new members of 1P and 2S charmed baryons Bing Chen, Xiang Liu, e-Print: arXiv: they have wave functions, so can calculate coefficients, calculate other known states. different mass ordering than KR, widths do not agree
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Quantum numbers of recently discovered Ω0c baryons from lattice QCD
M. Padmanath, Nilmani Mathur, e-Print: arXiv: h.f. splitting 70 MeV
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