Produconsanddecaysof charmed*baryons...Charmed baryons Whatdo!we!expectfor!heavy!quarks? • Qqq...

λ

ρ

Produc'ons and decays of charmed baryons

Nov.30 -‐-‐ Dec.1, 2014 Progress on J-‐PARC hadron 1

Atsushi Hosaka, RCNP, Osaka Progress on J-‐PARC hadron physics in 2014, J-‐PARC

Contents 1. Introduction -- Exotics with heavy quarks 2. Charmed baryons: to probe ρλ modes diquark 3. Productions 4. Decays

With Noumi, Shirotori, Kim, Sadato, Yoshida, Oka, Hiyama Prog. Theor. Exp. Phys. (2014) 103D01

1. Introduction


50 year of quarks


Already proposed by

12 year of quarks

Fermi Lab

SLAC

LHC


Quarks bonding differently at LHCb


hJp://www.theguardian.com/science/life-‐and-‐physics/2014/apr/13/quarks-‐bonding-‐differently-‐at-‐lhcb

So until last week there were two known types of hadron. ...... LHCb has just confirmed what data from other experiments had already led us to suspect. There is a third way.

Phys. Rev. LeJ. 112, 222002

Zb(10610, 10650)@KEK 2012 1/10


Bファクトリー実験において、ボトム・クォークを含む新種のハドロン粒子を発見した。この新粒子は電荷を持ち、4個以上のクォークが結合してできたハドロン粒子と考えられる。... 今回の発見は、4個以上のクォークが結合したエキゾチックハドロンが、ボトム・クォークを含む粒子系にも存在することを明らかに示したものである。

Z(3900)

Z(4430)

7

X(3872)

qq qq

What we expect: Creation and rearrangement of multiquarks

ηc

′ηc

J ψ

′ψ

χc0χc1

χc2

N=0

N=1

N=2

N=3 qqqq

? ?

creation (constituent) Clustering Meson-like Diquarks

qq

What governs them ? 2.8

3.0

3.2

3.4

3.6

3.8

4.2

Nov.30 -‐-‐ Dec.1, 2014 Progress on J-‐PARC hadron

S=3/2

S=1/2

14c ＋1cc << 80uds (6excited)

1/2+

1/2 – 1/2+

3/2+

1/2–

1/2+

3/2+

3/2 –

5/2+

?

ΞC

[GeV]

?

1/2+

3/2+

ΩC

cqq cqq

csq

css ΞC

Ξ’C

1hω

?

1 Ξ+cc


Ground states

More states at JPARC

2. Charmed baryons

What do we expect for heavy quarks?

• Qqq distinguishes the two modes of λ and ρ Diquark motions in the baryon mass spectrum • It could expose light flavor (chiral) dynamics


From hadron to diquark (spectroscopy)

λ

ρ


λ, ρ modes appear in the spectrum

λ

ρρ > λ

λ

ρ ρ = λ

HO and no ss λ

ρ

Degenerate ß Two diquark motions à Distinguished Isotope-shift

mQ = mu,d mQ →∞

qqQ systems


Quark model calculation with spin-spin interaction: Yoshida, Sadato, Hiyama, Oka, Hosaka

Quark model hamiltonian

H = p12

2mq+ p2

2

2mq+ p3

2

2MQ− P2

2Mtot

+Vconf (HO)+Vspin−spin (Color −magnetic)+ ...Solved by the Gaussian expansion method

See how systems change as MQ is varied

Excitabon spectrum

Σ(1/2+)

Λ(1/2+)

Σ(3/2+) Λ(1/2-, 3/2-)

Λ Σ Σ

Σ Λ

Hyperons

Nov.30 -‐-‐ Dec.1, 2014 12

Charmed baryons

Σc(1/2+)

Λc(1/2+)

Σc(3/2+)

Λc(1/2-, 3/2-)

Λc

Σc

Λc

Σc

Σc

L=1 excited states: spin-‐spin interacbon

Progress on J-‐PARC hadron

ß l = 0, ground states à

ß l = 1, excited states à

Excitabon spectrum

Σ(1/2+)

Λ(1/2+)

Σ(3/2+) Λ(1/2-, 3/2-)

Λ Σ Σ

Σ Λ

Hyperons

Nov.30 -‐-‐ Dec.1, 2014 13

Charmed baryons

Σc(1/2+)

Λc(1/2+)

Σc(3/2+)

Λc(1/2-, 3/2-)

Λc

Σc

Λc

Σc

Σc



0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 MQ [GeV/c2]

s c

Excitabon spectrum

Σ(1/2+)

Λ(1/2+)

Σ(3/2+) Λ(1/2-, 3/2-)

Λ Σ Σ

Σ Λ

Hyperons

Nov.30 -‐-‐ Dec.1, 2014 14

Charmed baryons

Σc(1/2+)

Λc(1/2+)

Σc(3/2+)

Λc(1/2-, 3/2-)

Λc

Σc

Λc

Σc

Σc



0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 MQ [GeV/c2]

s c SU(3) HQ

Wave funcbon

Nov.30 -‐-‐ Dec.1, 2014 Progress on J-‐PARC hadron

15 mQ [GeV]

mud = 300 MeV

Prob

abili

ty |c

|2 Mixing of

e.g. λ-mode dominant state: How much the other mode mixes? Λ(phys) = cλΛ(

2λ)+ cρΛ(2 ρ)

| cλ (Λ(1 / 2− )) |2

| cλ (Σ(1 / 2− )) |2

| cρ (Λ(1 / 2− )) |2

| cρ (Σ(1 / 2− )) |2

0

0.2

0.4

0.6

0.8

1

0 0.5 1 1.5 2

SU(3) limit

Λc* is almost

pure λ mode è Reflect more diquark nature

3. Charmed baryon Productions


Production rate (Λc/Λ) and Ratios (Bc*/Bc)

π + N à D* + Λc reactions

Strategy: At high energies: Forward peak à t-channel dominant Theory: • Rates (Λc/Λ) by the Regge model, D* Reggeon • Relative ratios of (Bc

*(λ modes)/Bc) by a One step process of Qd picture

APS-‐JPS joint meebng 17 d

q(pi ) c(p f )Pion-induced reaction π + p D* + Bc

*

π D*

Bc* p

D* Reggeon


pπ, Lab = 4.5 GeV

π − p→ΛK*0 π − p→ ΣK*0

cosθ cosθ

1

10

0.1 –1.0 0 +1.0 –1.0 0 +1.0

dσdΩ[µb / sr]

D.J. Krennel et al PRD6, 1220 (1972)


Absolute values


Regge model ~ Sang-Ho Kim's talk

strangeness

charm

10–2

10–5

Charm/strangeness productions: 10–2 ~ 10–5


Relative rates of (Bc*/Bc) ��

One step process of Qd pictire

t fi ~kπ × e ⋅

J fi

~ Bc* e⊥ ⋅

σ ei

qeff ⋅x N

Transverse = (Geometric) × (Dynamic) CG coefficients

d

q(pi ) c(p f )λ

V-exchanges

D*π

Bc*

Kim et al, PTEP (2014) 103D01

Dynamical part ~ radial integral


GS

Transitions to excited states are not suppressed

Bc(S-wave)

e⊥ ⋅σ ei

qeff ⋅x N (S-wave) radial ~1× exp −

qeff2

4A2⎛

⎝⎜

⎞

⎠⎟

Bc(P-wave)

e⊥ ⋅σ ei

qeff ⋅x N (S-wave) radial ~

qeffA

⎛⎝⎜

⎞⎠⎟

1

× exp −qeff2

4A2⎛

⎝⎜

⎞

⎠⎟

Bc(D-wave)

e⊥ ⋅σ ei

qeff ⋅x N (S-wave) radial ~

qeffA

⎛⎝⎜

⎞⎠⎟

2

× exp −qeff2

4A2⎛

⎝⎜

⎞

⎠⎟

Excited states

d

q(pi ) c(p f )qeff: the momentum transfer ~ Large

Results

Strange kπCM = 1.59 [GeV], kπLab = 5.8 [GeV]


1.00 0.02 0.16 0.90 1.70 0.02 0.03 0.04 0.19 0.18 0.50 0.88 0.02 0.02 0.01 0.03 0.07 0.07

Charm kπCM = 2.71 [GeV] , kπLab = 16 [GeV]

1.00 0.067 0.44 0.11 0.23 0.007 0.01 0.01 0.07 0.067 0.13 0.20 0.007 0.01 0.004 0.02 0.038 0.04

Yasui's talk, wed à 1/ 2+ 1/ 2− 3 / 2− 3 / 2+ 5 / 2+

HQ doublet HQ doublet

l = 1 l = 2 l = 0

1 : 2 3 : 2



Meson analogue

d

q(pi ) c(p f )

D*π

Bc λ

r

How similar the λ baryon mode and r meson mode?

4. Charmed baryon decays


ρ-mode λ-mode

Bc*

Mc

N π

Bc*

Bc

Chiral dynamics


Spontaneously broken = SU(2)L x SU(2)R à SU(2)V Non-linear realization with only ispsoin symmetry S. Weinberg, Phys.Rev.166, 1568 (1968)

U = exp ifπ

τ ⋅ π⎛⎝⎜

⎞⎠⎟, U→ gLUgR

†

ξ = exp i2 fπ

τ ⋅ π⎛⎝⎜

⎞⎠⎟, ξ → gLξh

† = hξg†L , h = h(gL ,gR ,π )

vµ , aµ = i2

ξ† ∂µξ ±ξ ∂µξ†( )

N→ξN , DµN ≡ (∂µ− ivµ )N→ξDµN• • • •

Linear descripbon


Again by S. Weinberg, Algebraic realization, Phys.Rev.177, 2604 (1969) Mended symmetries, PRL65, 1177 (1990)

• Assign chiral representations to hadrons • Then write a chiral invariant Lagrangian terms

etc

N ~ 12 , 0( )⊕ 0, 12( ); NL,R → gL,RNL,R , NL,R = 1+ γ 5

2N

(σ , π ) ~ 12 ,

12( ), (ρ, a1) ~ 1, 0( )⊕ 0,1( )

NLUNR + NRU†NL = N σ + iτ ⋅ πγ 5( )N

Meson-‐baryon coupling


Light meson qq (½, ½) Nucleon qqq (½, 0), (1, ½) Heavy meson (quark) Qq (½, 0) Heavy baryon (diquark) Qqq (0, 0), (½, ½), (1, 0)

Diquark JP Chiral Isospin Baryons S 1S0 0+ (0, 0) 0 Λ, Λ*(λ) P 3P0 0– (0, 0) 0 Λ*(ρ) V 3P1 1– (½, ½) 0 Λ*(ρ) A 3S1 1+ (½, ½) 1 Σ, Σ*(λ) T 3D1, 1P1 1+, 1– (1, 0) 1 Σ, Σ*(ρ)

qqqγ 5qqγ µqqγ µγ 5

τ qqσ µνγ 5

τ q

q =T qiγ 0γ 2γ 5iτ 2


Bc* à π Bc

π Bc (½, ½)×(0, 0) (½, ½)×(½, ½) (½, ½)×(0, 1) [1] (0, 0) --- OK --- [2] (½, ½) OK --- OK [3] (1, 0) --- OK ---

Bc*

[1] Λ*(λ) à πΣ [2] Λ*(ρ), Σ*(λ) à πΛ, πΣ, these are related [3] Σ*(ρ) à πΛ, πΣ


Bc* à Mc N(½,0), (1,½)

Mc N (0, ½)×(0, ½) (0, ½)×(½, 1) [1] (0, 0) OK --- [2] (½, ½) --- OK [3] (1, 0) --- OK

Bc*

[1] Λ*(λ) à KN [2] Λ*(ρ), Σ*(λ) à KN [3] Σ*(ρ) à KN

• Chiral selection rules may explain small widths • explore more on the nucleon

Summary • Evidences of new mulbquark configurabons è Molecule + ... • To pin down the dynamics, J-‐PARC will help

• ρ and λ modes are disbnct (Isotope shin) beJer in Λ than in Σ à can we approach di-‐quark ? • Systemabc study in strangeness is important

• Higher excited (Λ) states may be produced as many as the ground states, analogue for mesons • Chiral selecbon rules may be relevant to small width

• More on the chiral structure of the nucleon


Produconsanddecaysof charmed*baryons...Charmed baryons Whatdo!we!expectfor!heavy!quarks? • Qqq...

Documents

Transcript of Produconsanddecaysof charmed*baryons...Charmed baryons Whatdo!we!expectfor!heavy!quarks? • Qqq...

Producons*and*decays*of* charmed*baryons...Charmed baryons Whatdo!we!expectfor!heavy!quarks? • Qqq...

Documents

Transcript of Producons*and*decays*of* charmed*baryons...Charmed baryons Whatdo!we!expectfor!heavy!quarks? • Qqq...

Produconsanddecaysof charmed*baryons...Charmed baryons Whatdo!we!expectfor!heavy!quarks? • Qqq...

Transcript of Produconsanddecaysof charmed*baryons...Charmed baryons Whatdo!we!expectfor!heavy!quarks? • Qqq...