Transcript Lifetime of doubly charmed baryons

Lifetime of doubly charmed baryons
Chao-Hsi Chang(ITP), Tong Li(NKU), Xue-Qian Li(NKU), Yu-Ming
Wang(NKU)
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Introduction
Formulation for Lifetimes of
Evaluation of Hadronic Matrix Elements
Numerical Results
Summary
Introduction
(ccd) observed by SELEX Collaboration at
FERMILAB (PRL89,112001(2002))
 Previous works on doubly heavy-quark baryon
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(PRD60,014007(1999); hep-ph/9912424;
Eur.Phys.J.C9,213(1999))
 WE/WA and PI mechanism(PLB280,271(1992);
PLB293,430(1992); Nucl.Phys.B399,441(1993))
 Hadronic wave function
Formulation for Lifetimes of
 The general formula for inclusive decay width
(lifetime): optical theorem
 OPE of matrix element
Spectator Contribution
 The total decay width can be decomposed into
two parts:
 Spectator contribution can be decomposed into
two components:
 The semileptonic and nonleptonic decay of
spectator contribution have been calculated by
many authors. (Bigi et al., hep-ph/9401298;
PRD56,2783(1997); PRD64,014003(2001))
Non-spectator Contribution
 Effective Lagrangian
 Our calculation includes CKMsuppressed contribution.
The inclusive decays of
(ccd)
The inclusive decays of
(ccu)
The inclusive decays of
(ccs)
Hadronic Matrix Elements
 Sandwiching the operators between initial and
final states
of forward scattering,
we obtain the hadronic matrix elements:
Harmonic oscillator wave function
The decay widths
Numerical Results
 Input parameters
(PRD60,014007(1999); hep-ph/9912424; Eur.Phys.J.C9,213(1999))
Non-perturbative parameters
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reflects the coupling of the two c quarks,
we adopt the parameter the same as J/ψ
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reflects the coupling of two c quarks
and the light quark (u, d, s), we adopt the
parameter the same as D meson
Compare with other work
 Lifetime of
Lifetime of
Lifetime of
strongly depend on the wavefunction
at the origin.
hep-ph/9912424
Summary
 Doubly charmed baryons
 Inclusive decay width
optical theorem, OPE, WE/WA and PI
mechanism
 Others (wave functions, other doubly
heavy-quark baryons, triply heavyquark baryon……)
Thank You!