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Production of charmed baryons -- Rough estimate -- Atsushi Hosaka, RCNP (Osaka U) Rate for charm and strange productio Effective Lagrangian and Regge Production of various baryons states Quark-diquark model 12/03, 2012 JPARC-Collab 1

Production of charmed baryons -- Rough estimate --

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Atsushi Hosaka , RCNP (Osaka U). Production of charmed baryons -- Rough estimate --. • R ate for charm and strange productions Effective Lagrangian and Regge • Production of various baryons states Quark- diquark model. Charm and strange productions. Strategy. - PowerPoint PPT Presentation

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Page 1: Production of charmed baryons -- Rough estimate --

Production of charmed baryons-- Rough estimate --

Atsushi Hosaka, RCNP (Osaka U)

• Rate for charm and strange productions Effective Lagrangian and Regge

• Production of various baryons states Quark-diquark model

12/03, 2012 JPARC-Collab 1

Page 2: Production of charmed baryons -- Rough estimate --

Charm and strange productions

12/03, 2012 JPARC-Collab 2

• We do not know much about charm production

• Use an appropriate model for strange production from medium to high energy

• Kinematically extend the model to the charm region

Effective Lagrangian and/or Regge

Strategy

Page 3: Production of charmed baryons -- Rough estimate --

12/03, 2012 JPARC-Collab 3

1

10–1

10–2

101

ωφ

J/ψ

ρ

Total γp Vp

W [ GeV]

102

μb

102101

~ 100

About 100 times smaller than strangeness production

What about for the pion induced reaction

Page 4: Production of charmed baryons -- Rough estimate --

Effective Lagrangian

12/03, 2012 JPARC-Collab 4

• Four possible processes; s, t, u and contact• At high energies and forward region, t-dominates s: suppressed, no resonance above 3 GeV u: suppressed kinematically c: unknown

• D, D* exchanges allowed, but scalar is not

π

NN

D*

Page 5: Production of charmed baryons -- Rough estimate --

D-exchange

12/03, 2012 JPARC-Collab 5

π

NN

D*

D

Page 6: Production of charmed baryons -- Rough estimate --

0.5 0.7 0.9 1.1 1.3 1.50.00

5.00

10.00

15.00

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 10

10

20

30

40

50

k (cm) GeV

π+P ρ+p Light flavor, u,d

F1: 8 mb

F2: 7 mb

Page 7: Production of charmed baryons -- Rough estimate --

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 10

0.05

0.1

0.15

0.2

k (cm) GeV

π+P K*+Λ(1116)

0.7 0.9 1.1 1.3 1.5 1.70

0.05

0.1

0.15

0.2

Strangeness

F1: 8 mb ------> 0.07 mb

F2: 7 mb ------> 0.04 mb 1/120

1/170

Page 8: Production of charmed baryons -- Rough estimate --

k (cm) GeV

π+P D*+Λc(2226)

2 2.5 31E+00

1E+02

-1 -0.5 0 0.5 11E-08

1E-07

1E-06

1E-05

1E-04

1E-03

1E-02

1E-01

Charm

F1: 8 mb ------> 0.07 mb ------> 0.0006 mb

F2: 7 mb ------> 0.04 mb ------> 0.00002mb = 20pb1/120 1/120

1/170 1/2000

Page 9: Production of charmed baryons -- Rough estimate --

Regge's mechanism -- Brief idea --

12/03, 2012 JPARC-Collab 9

Resonances K*, … can be exchanged

No resonance exists with Q = 2 t-channel

×

Page 10: Production of charmed baryons -- Rough estimate --

t-channel amplitude

12/03, 2012 JPARC-Collab 10

lt = 0, 1, 2, …

For l = σ

This violates unitarity Need to sum over all l

Regge's method

Regge trajectoryForm factor~ forward peak

Page 11: Production of charmed baryons -- Rough estimate --

0 < t Physical particle region

t < 0Scattering region

Regge trajectory

Page 12: Production of charmed baryons -- Rough estimate --

Features

12/03, 2012 JPARC-Collab 12

• Determines the asymptotic behavior s ∞• Gives forward peak (diffractive pattern)• Agrees well with high energy scattering data ~ few hundred MeV above the strangeness threshold

BUT difficult to determine• Absolute production rates• Form factors (t-dependence)

Therefore, we may use• For relative production rate• At forward angle

Page 13: Production of charmed baryons -- Rough estimate --

Vector vs Pscalar trajectory

12/03, 2012 JPARC-Collab 13

Vector >> Pscalar at large s

Page 14: Production of charmed baryons -- Rough estimate --

Vector Reggeon, some model dependence

Page 15: Production of charmed baryons -- Rough estimate --

12/03, 2012 JPARC-Collab 15

• Naïve Regge

• Kaidalov

This is partly regarded as ambiguity in s0

• Grishina

• Kaidalov

Page 16: Production of charmed baryons -- Rough estimate --

1E+00 1E+011E-05

1E-04

1E-03

1E-02

1E-01

1E+00

1E+01

1E+02

1E+03σtot [μb] Naïve-Kaidalov

Grishina

KaidalovNaive

Strange

Charm

Vector Reggeon, some model dependence

Grishina

Page 17: Production of charmed baryons -- Rough estimate --

Production of Bc in a quark-diquark model

12/03, 2012 JPARC-Collab 17

Page 18: Production of charmed baryons -- Rough estimate --

Quark-diquark baryonSelem-Wilczek: e-Print: hep-ph/0602128

• ee has repulsive force, BUT• qq has attractive force   SU(3)c :half of qqbar attraction    SU(2)c : Same as qqbar Pauli-Gursey symmetry ~ several hundred MeV

• Diquark can be seen better in heavy baryons

Color magnetic int.Good Bad

Page 19: Production of charmed baryons -- Rough estimate --

12/03, 2012 JPARC-Collab 19

d

Q

λ-mode

Pion induced charm production

λ-mode baryons

• D*-exchange couples to various B's lλ = 0, 1, 2 (18 baryons)• Estimate forward scattering strength ~ Regge shows• State dependence (ratio) is estimated by qd model

Page 20: Production of charmed baryons -- Rough estimate --

Transitions to Qd baryons

12/03, 2012 JPARC-Collab 20

λ

N(1/2+) Bc(JP)

Forward

Page 21: Production of charmed baryons -- Rough estimate --

Computation of matrix elements

12/03, 2012 JPARC-Collab 21

1

Page 22: Production of charmed baryons -- Rough estimate --

Baryon wave functions

12/03, 2012 JPARC-Collab 22

Orbital

Spinχρ S=1/2 of good d (S = 0) + cχλ S=1/2 of bad d (S = 1) + cχS S=3/2 of bad d (S = 1) + c

Isospin Similar to spin WF

Nucleon

Charmed baryons

Page 23: Production of charmed baryons -- Rough estimate --

Radial matrix elements IL

12/03, 2012 JPARC-Collab 23

Page 24: Production of charmed baryons -- Rough estimate --

Results

12/03, 2012 JPARC-Collab 24

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 kπ = 2.71 [GeV]

Page 25: Production of charmed baryons -- Rough estimate --

Results

Strange kπ = 1.59 [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

12/03, 2012 JPARC-Collab 25

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 kπ = 2.71 [GeV]

Page 26: Production of charmed baryons -- Rough estimate --

Summary

12/03, 2012 JPARC-Collab 26

• Regge approach: R(c)/R(s) = 1/100 – 1/1000• Forward peak

• Qd model shows spin-dependent rate• Some higher L states may have large production rate comparative to the ground state