Mixing and decays of the antidecuplet in the context of approximate - - PDF document

▶
mixing and decays of the antidecuplet in the context of
SMART_READER_LITE
LIVE PREVIEW

Mixing and decays of the antidecuplet in the context of approximate - - PDF document

Oct 08, 2023 29 likes •211 views

Mixing and decays of the antidecuplet in the context of approximate SU(3) symmetry Vadim Guzey (Bochum) and M.V. Polyakov (Liege) 1. Motivation 2. Antidecuplet mixed with three octets: General expressions for 10 partial decay widths 3. Emerging

slide-1
SLIDE 1

Mixing and decays of the antidecuplet in the context of approximate SU(3) symmetry Vadim Guzey (Bochum) and M.V. Polyakov (Liege)

  • 1. Motivation
  • 2. Antidecuplet mixed with three octets: General expressions

for 10 partial decay widths

  • 3. Emerging picture of N10 and Σ10 decays
  • 4. Discussion (influence of the mixing with 27-plet, ideal mixing)

and conclusions

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-2
SLIDE 2

Motivation

  • Approximate flavor SU(3) symmetry of strong interactions

allows to group all hadrons into certain multiplets. Only singlets, octets (8) and decuplets (10) were believed to be realized in Nature. The discoveries of the Θ+ and Ξ−−, if confirmed, mean the existence of a new physical multiplet: the antidecuplet (10).

  • Approximate SU(3) symmetry works surprisingly well: Mass

splittings and partial decay widths of all baryon multiplets (singlets, octets, decuplets) are described and predicted with good accuracy: Gell-Mann and Ne’eman 1964; Kokkedee 1969;

Samios, Goldberg, Meadows 1974.

  • Approximate SU(3) suits best for establishing in a model-

independent way the overall structure of a given SU(3) multiplet: Mass splittings, necessity of mixing with other multiplets due to SU(3) breaking, correlations between partial decay widths.

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-3
SLIDE 3
  • This is exactly what one needs for the antidecuplet: a reliable
  • verall picture of 10 and its mixing with other multiplets and

a way to systemize the present experimental info on the 10 decays.

  • Since SU(3) is broken, states from different multiplets with

the same spin and parity can mix. Because of the small width

  • f Θ+, even small mixing dramatically affects predictions for

the 10 decays. At the same time, small mixing with 10 affects very little non-exotic multiplets. This means that one can use the results of SU(3) analysis of the non-exotic multiplets (three

  • ctets in our case) in the SU(3) analysis of 10 decays.
  • After the SU(3) picture of 10 is established using the scarce

experimental info on 10 decays, one can make model- independent predictions for unmeasured decays and assess available models of the 10 mixing.

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-4
SLIDE 4

Antidecuplet mixing with three octets We consider the scenario that 10 mixes with three J P = 1/2+ octets: the ground-state octet, the octet containing N(1440) Λ(1600), Σ(1660) and Ξ(1690), the octet containing N(1710), Λ(1800), Σ(1880) and Ξ(1950). The mixing takes place through the N10 and Σ10 and the corresponding N and Σ octet states:

     |N phys

1

  • |N phys

2

  • |N phys

3

  • |N phys

10

    =      1 sin θ1 1 sin θ2 1 sin θ3 − sin θ1 − sin θ2 − sin θ3 1           |N1 |N2 |N3 |N10     

  • We assume that θi mixing angles are small, θi = O(ǫ), where

ǫ is a small parameter of SU(3) breaking. We systematically neglect O(ǫ2) terms.

  • The |N1, |N2 and |N3 states can mix among themselves,

i.e. they can belong to several different octets. Using the χ2 fit to the measured decays, we find that |N2 and |N3 states are slightly mixed (it is legitimate to neglect 10 at this stage.

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-5
SLIDE 5

After this is taken into account, it is sufficient to consider

  • nly the mixing of each individual |N phys

i

with |N phys

10

.

  • The mixing angles θi and θΣ

i are related,

sin θi

  • N phys

i

− N phys

10

  • = sin θΣ

i

  • Σphys

i

− Σphys

10

  • ,

which becomes θi = θΣ

i ignoring O(ǫ2) terms.

  • Gell-Mann–Okubo mass formulas, which describe the mass

splitting inside SU(3) multiplets, are not sensitive to small mixing

N phys

i

≡ N phys

i

| ˆ M|N phys

i

= Ni + sin2 θiN10 = Ni + O(ǫ2) ,

It is not legitimate to estimate the mixing angles from the Gell-Mann–Okubo mass formula. Instead, one has to consider decays which contain both O(1) and O(ǫ) terms.

  • We assume that SU(3) symmetry is violated by non-equal

masses inside a given multiplet and mixing and that SU(3) is exact in decay vertices → finite number of universal SU(3) coupling constants.

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-6
SLIDE 6

General expressions for 10 couplings: ΓΘ+ and G10 In our analysis, ΓΘ+ and Σπ N are external parameters, which are varied in the following intervals: 1 ≤ ΓΘ+ ≤ 5 MeV; 45 ≤ Σπ N ≤ 75 MeV. Σπ N determines the θ1 mixing angle with the ground state

  • ctet; ΓΘ+ determines the G10 and H10 (H10 = 2 G10 − 18)

coupling constants using

Praszalowicz, hep-ph/0402038; R.A. Arndt et al., PRC 69 (2004) 035208 gΘ+N K = 1 √ 5

  • G10 + sin θ1H10

√ 5 4

  • 10
  • 8
  • 6
  • 4
  • 2

2 4 6 8 10 45 50 55 60 65 70 75

ΣπN, MeV G10

ΓΘ+=1 MeV ΓΘ+=3 MeV ΓΘ+=5 MeV

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-7
SLIDE 7

General expressions for N10 couplings

gN10N π = 1 2 √ 5  G10 + sin θ1

  • H10

√ 5 4 − G8 7 √ 5

  • −
  • i=2,3

sin θi gNiN π   , gN10N η = 1 2 √ 5  −G10 + sin θ1

  • H10

√ 5 4 − G8 1 √ 5

  • +
  • i=2,3

sin θi gNiN η   , gN10Λ K = 1 2 √ 5  G10 + sin θ1G8 4 √ 5 +

  • i=2,3

sin θi gNiΛ K   , gN10∆ π = 2 √ 5  sin θ1G8 +

  • i=2,3

sin θi gNi∆ π  

  • The gNiB P coupling constants are determined by the χ2 fit

to the measured decays of the octets; the θ2,3 are left as free parameters.

  • Important correlation: Mixing with the octets can decrease

gN10N π and simultaneously increase gN10N η.

  • The N10∆ π decay is possible only due to mixing.
  • The partial decay widths are found from

Γ(B1 → B2 + P ) = 3|gB1B2P|2 | p|3 2π(M1 + M2)2 M2 M1

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-8
SLIDE 8
  • Part. decay width Γ(N*→ N π), MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 5 10 15 20 25 30 35 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 10 20 30 40 50 60 70 80 90 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 2.5 5 7.5 10 12.5 15 17.5 20 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 10 20 30 40 50 60 sin θ

2

sin θ3

ΣπN=75 MeV

  • Part. decay width Γ(N*→ N η), MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 1.4 1.6 1.8 2 2.2 2.4 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 3.6 3.8 4 4.2 4.4 4.6 4.8 5 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 3.8 4 4.2 4.4 4.6 4.8 5 5.2 5.4 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 6 6.25 6.5 6.75 7 7.25 7.5 7.75 8 sin θ

2

sin θ3

ΣπN=75 MeV

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-9
SLIDE 9
  • Part. decay width Γ(N*→ ΛK), MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 1 1.5 2 2.5 3 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 1.5 2 2.5 3 3.5 4 4.5 sin θ

2

sin θ3

ΣπN=75 MeV

  • Part. decay width Γ(N*→ ∆π), MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.15
  • 0.1
  • 0.05

0.05 0.1 0.15 0.2 20 40 60 80 100 120 140 sin θ2 s i n θ

3

ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.15
  • 0.1
  • 0.05

0.05 0.1 0.15 0.2 25 50 75 100 125 150 175 200 225 sin θ2 s i n θ

3

ΣπN=75 MeV

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-10
SLIDE 10

What is presently known about N10?

  • The PWA analysis of R.A. Arndt et al., PRC 69 (2004) 035208

gives two candidate states with masses 1680 MeV and 1730

  • MeV. Both states should have ΓN10→N π ≤ 0.5 MeV.
  • GRAAL observes a narrow nucleon resonance near 1670 MeV

in the reaction γ n → n η V. Kuznetsov for the GRAAL Collab.,

hep-ex/0409032. Interpretation: ΓN10→N η should not be too

small.

  • STAR observes a narrow peak at 1734 MeV and only a

weak indication of a narrow peak at 1693 MeV in the Λ KS invariant mass S. Kabana for the STAR Collab., hep-ex/0406032. Interpretation: ΓN10→Λ K is possibly suppressed. We find that this picture of N10 decays can be realized by suitable choice of θi. In particular, we impose the ΓN10→N π ≤ 1 MeV cut and find unsuppressed ΓN10→N η and somewhat suppressed ΓN10→Λ K.

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-11
SLIDE 11
  • Part. decay width Γ(N*→ N π), MeV: ΓN*→ N π< 1 MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 sin θ

2

sin θ3

ΣπN=75 MeV

  • Part. decay width Γ(N*→ N η), MeV: ΓN*→ N π< 1 MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.25 0.5 0.75 1 1.25 1.5 1.75 2 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.5 1 1.5 2 2.5 3 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 1 2 3 4 5 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 1 2 3 4 5 6 7 sin θ

2

sin θ3

ΣπN=75 MeV

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-12
SLIDE 12
  • Part. decay width Γ(N*→ ΛK), MeV: ΓN*→ N π< 1 MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 0.6 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.2 0.4 0.6 0.8 1 1.2 1.4 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 sin θ

2

sin θ3

ΣπN=75 MeV

  • Part. decay width Γ(N*→ ∆π), MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 2 4 6 8 10 12 14 16 18 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 1 2 3 4 5 6 7 8 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 5 10 15 20 25 30 35 40 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 5 10 15 20 25 sin θ

2

sin θ3

ΣπN=75 MeV

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-13
SLIDE 13

General expressions for Σ10 couplings

gΣ10Λ π = 1 2 √ 5  G10 − sin θΣ 1 G8 3 √ 5 −

  • i=2,3

sin θΣ i gΣiΛ π   , gΣ10Σ π = 1 √ 30  G10 + sin θ1

  • H10

√ 5 2 − G8 √ 5

  • −
  • i=2,3

sin θΣ i gΣiΣ π   , gΣ10N K = 1 √ 30  −G10 + sin θ1H10 √ 5 2 + sin θΣ 1 G8 4 √ 20 +

  • i=2,3

sin θΣ i gΣiN K   , gΣ10Σ10 π = √ 30 15  G8 sin θ1 +

  • i=2,3

sin θΣ i gΣiΣ10 π  

  • There are no distinct correlations among the partial decay

widths when θ2,3 are free

  • Imposing the ΓN10→N π ≤ 1 MeV cut,

we can have ΓΣ10N K > ΓΣ10Λ π, ΓΣ10Σ π. Σ10 looks like a narrow Σ(1770)!

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-14
SLIDE 14
  • Part. decay width Γ(Σ*→ Λπ), MeV: ΓN*→ N π< 1 MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.5 1 1.5 2 2.5 3 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 1 2 3 4 5 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.5 1 1.5 2 2.5 3 3.5 4 4.5 sin θ

2

sin θ3

ΣπN=75 MeV

  • Part. decay width Γ(Σ*→ Σπ), MeV: ΓN*→ N π< 1 MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.2 0.4 0.6 0.8 1 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 0.6 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 sin θ

2

sin θ3

ΣπN=75 MeV

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-15
SLIDE 15
  • Part. decay width Γ(Σ*→ NK), MeV: ΓN*→ N π< 1 MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.5 1 1.5 2 2.5 3 3.5 4 sin θ

2

sin θ3

ΓΘ+=1 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.5 1 1.5 2 2.5 3 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 1 2 3 4 5 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 1 2 3 4 5 6 7 8 sin θ

2

sin θ3

ΣπN=75 MeV

  • Part. decay width Γ(Σ*→ Σ(1385)π), MeV: ΓN*→ N π< 1 MeV
  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 sin θ

2

sin θ3

ΓΘ+=1 MeV,ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 sin θ

2

sin θ3

ΣπN=75 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.5 1 1.5 2 2.5 sin θ

2

sin θ3

ΓΘ+=5 MeV, ΣπN=45 MeV

  • 0.2
  • 0.1

0.1 0.2

  • 0.2
  • 0.1

0.1 0.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 sin θ

2

sin θ3

ΣπN=75 MeV

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-16
SLIDE 16

What is presently known about Σ10?

  • This is the least known member of 10. We use mΣ10 = 1765

MeV (equally spaced between the N(1670) and Ξ−−(1862)).

  • Among the experiments reporting the Θ+ signal, there were

four experiments, where the Θ+ was observed as a peak in the p KS invariant mass. Since Σ10 decays in the same final state (N K), the four experiments give direct information on the Σ10 → N K decay!

  • The analysis of A.E. Asratyan, A.G. Dolgolenko and M.A. Kubantsev,
  • Phys. At. Nucl. 67, 682 (2004) reveals a number of peaks the

1650 < Mp KS < 1850 MeV mass range.

  • The analysis of SVD Collab., A. Aleev et al., hep-ex/0401024

contains at least two prominent peaks in the 1700-1800 MeV mass range, before the cuts.

  • The HERMES and ZEUS p KS invariant mass spectra extend
  • nly up to 1.7 MeV.

A possibly narrow Σ10(1765) should be searched for in the available data!

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-17
SLIDE 17

Discussion

  • In order to estimate theoretical uncertainty of our predictions,

we add an additional mixing of the antidecuplet with a 27-plet

  • J. Ellis, M. Karliner, M. Praszalowicz, JHEP 0405 (2004) 002.

We arrive at two scenarios. In the first case, the qualitative picture of the N10 decays does not change. The correlations between the Σ10 partial decay widths do change, which makes it impossible to identify Σ10 with Σ(1770). In the second case, the picture of N10 decays becomes only marginally compatible with experiment. The pattern of the Σ10 decays is similar to Σ(1770). Both N10 and Σ10 states are very narrow.

  • We find that the scenario of large (ideal) mixing is

incompatible with the notion of approximate SU(3) symmetry

Jaffe and Wiczek, PRL 91 (2003) 042003; D.K. Hong, hep-ph/0412132.

Identifying N10 with N(1710), which is ideally mixed with the Roper N(1440), the χ2 fit fails to simultaneously accommodate ΓΘ+ ≤ 10 MeV and a large ΓN(1440)→N π. An acceptably low χ2 can be only found assuming very small mixing, |θN| ≈ 40.

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey
slide-18
SLIDE 18

Conclusions

  • We considered mixing of the antidecuplet with three J P =

1/2+ octets in the framework of approximate flavor SU(3) symmetry and in the limit of small mixing angles.

  • We presented general expressions for the 10 partial decay

widths as functions of the three mixing angles and ΓΘ+.

  • Identifying N10 with the N(1670) observed by GRAAL, we

arrive at the following picture of 10 decays: Θ+ could be as narrow as 1 MeV; the N10 → N η decay is sizable, while the N10 → N π decay is suppressed and the N10 → Λ K decay is possibly suppressed.

  • Constraining the mixing angles by the N10 decays, we make

predictions for the Σ10 decays. We point out that Σ10(1765) could be searched for in the available data on KS p invariant mass spectrum, which already revealed the Θ+ peak. It is important to experimentally verify the decay properties

  • f Σ(1770) because its mass and J P = 1/2+ make it an

attractive candidate for Σ10.

Three Days of Hadronic Physics, 16.12.-18.12.2004, Spa, Belgium

  • V. Guzey