Heavy-quark spin symmetry for charmed and strange baryon resonances

The chiral SUð3Þ Lagrangian with charmed baryons of spin J P ¼ 1=2 þ and J P ¼ 3=2 þ is analyzed. We consider all counterterms that are relevant at next-to-next-to-next-to-leading order (N 3 LO) in a chiral extrapolation of the charmed baryon masses. At N 2 LO we find 16 low-energy parameters. There are three mass parameters for the antitriplet and the two sextet baryons, six parameters describing the mesonbaryon vertices and seven symmetry breaking parameters. The heavy-quark spin symmetry predicts four sum rules for the meson-baryon vertices and degenerate masses for the two baryon sextet fields. Here a large-N c operator analysis at next-to-leading order (NLO) suggests the relevance of one further spin-symmetry breaking parameter. Going from N 2 LO to N 3 LO adds 53 ¼ 17 þ 36 parameters. For the leading symmetry conserving two-body counterterms involving two baryon fields and two Goldstone boson fields we find 36 terms. While the heavy-quark spin symmetry leads to 36 − 16 ¼ 20 sum rules, an expansion in 1=N c at NLO generates 36 − 7 ¼ 29 parameter relations. A combined expansion leaves six unknown parameters only. For the symmetry breaking counterterms we find 17 terms, for which there are 17 − 9 ¼ 8 sum rules from the heavy-quark spin symmetry and 17 − 5 ¼ 12 sum rules from a 1=N c expansion at NLO.

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“…For more technical details see for example [22][23][24][25]. The basic building blocks of the chiral Lagrangian are [3] , B [6] , B µ [6] ,…”

Section: Chiral Lagrangian With Charmed Baryon Fieldsmentioning

confidence: 99%

“…where we include the pseudoscalar meson octet fields Φ(J P = 0 − ), the baryon fields B [3] (J P = 1 2 + ), B [6] (J P = 1 2 + ) fields B µ [6] (J P = 3 2 + ). Explicit chiral symmetry-breaking is included in terms of scalar and pseudoscalar fields χ ± .…”

Section: Chiral Lagrangian With Charmed Baryon Fieldsmentioning

confidence: 99%

Combined large-Ncand heavy-quark operator analysis for the chiral Lagrangian with charmed baryons

2014

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“…Heavy quark spin symmetry (HQSS) has been applied to calculate baryon spectra in Refs. [5][6][7][8][9][10][11][12]. The basic idea behind these works is to use HQSS to reduce the freedom in the interaction, which is then written in terms of a few parameters which are adjusted to some experimental data.…”

Section: Introductionmentioning

confidence: 99%

Baryon states with open charm in the extended local hidden gauge approach

et al. 2015

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In this paper we examine the interaction of DN and D * N states, together with their coupled channels, by using an extension of the local hidden gauge formalism from the light meson sector, which is based on heavy quark spin symmetry. The scheme is based on the use of the impulse approximation at the quark level, with the heavy quarks acting as spectators, which occurs for the dominant terms where there is the exchange of a light meson. The pion exchange and the WeinbergTomozawa interactions are generalized and with this dynamics we look for states generated from the interaction, with a unitary coupled channels approach that mixes the pseudoscalar-baryon and vector-baryon states. We find two states with nearly zero width which are associated to the Λ c (2595) and Λ c (2625). The lower state, with J P = 1/2 − , couples to DN and D * N , and the second one, with J P = 3/2 − , to D * N . In addition to these two Λ c states, we find four more states with I = 0, one of them nearly degenerate in two states of J = 1/2, 3/2. Furthermore we find three states in I = 1, two of them degenerate in J = 1/2, 3/2. * liangwh@gxnu.edu.cn 1 I. INTRODUCTIONIn dealing with hadronic states involving heavy quarks (charm or beauty) the heavy quark spin symmetry [1][2][3][4] plays an important role and serves as a guiding principle to proceed with calculations. Heavy quark spin symmetry (HQSS) has been applied to calculate baryon spectra in Refs. [5][6][7][8][9][10][11][12]. The basic idea behind these works is to use HQSS to reduce the freedom in the interaction, which is then written in terms of a few parameters which are adjusted to some experimental data. Then predictions on spectra of baryons with charm or beauty, or hidden charm and beauty are made. In Ref.[5] an SU(8) spin-flavor scheme is used, to account for the spin symmetry, in order to obtain the interaction, and a coupled channels unitary approach is implemented to obtain poles in the scattering matrices, which correspond to the baryon resonance states. In particular the Λ c (2595) state is obtained and shown to couple largely to the D * N channel. In Ref.[8] the SU(8) scheme is once again used, but with some symmetry breaking, to match with an extension of the WeinbergTomozawa interaction in SU(3). Among other resonances, the states Λ c (2595) (J P = 1/2 − ) and Λ c (2625) (J P = 3/2 − ) are obtained. Further steps on the relationship of the Weinberg-Tomozawa interaction and HQSS are given in Refs. [10,13], where it is shown that this interaction, which stems from the exchange of vector mesons in the local hidden gauge approach [14][15][16] (see also Ref.[17] for practical rules), fulfills the HQSS. Indeed, the dominant terms correspond to the exchange of light vectors (the exchange of heavy vectors is suppressed), the heavy quarks act as spectators and hence the interaction does not depend on them. HQSS is then automatically fulfilled. Another step forward in this direction was given in Ref. [18], where using the impulse approximation at the quark level, the Weinb...

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“…[8] for practical rules) and the interaction kernel projected over s-wave results in the form of the Weinberg-Tomozawa interaction [3,4,[9][10][11][12][13]. The heavy quark spin symmetry (HQSS) is known to play an important role in the heavy quark sector [14][15][16][17] and has been utilized to investigate the hadron spectroscopy in the high energy region [1,[18][19][20][21][22][23][24]. Yet, it was also found in Ref.…”

Section: Introductionmentioning

confidence: 99%

Baryon states with hidden charm in the extended local hidden gauge approach

Uchino

Oset

2016

Eur. Phys. J. A

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The s-wave interaction ofDΛ c ,DΣ c ,D * Λ c ,D * Σ c andDΣ * c ,D * Σ * c , is studied within a unitary coupled channels scheme with the extended local hidden gauge approach. In addition to the Weinberg-Tomozawa term, several additional diagrams via the pion-exchange are also taken into account as box potentials. Furthermore, in order to implement the full coupled channels calculation, some of the box potentials which mix the vector-baryon and pseudoscalar-baryon sectors are extended to construct the effective transition potentials. As a result, we have observed six possible states in several angular momenta. Four of them correspond to two pairs of admixture states, two ofDΣ c −D * Σ c with J = 1/2, and two ofDΣ * c −D * Σ * c with J = 3/2. Moreover, we find aD * Σ c resonance which couples to theDΛ c channel and one spin degenerated bound state ofD * Σ * c with J = 1/2, 5/2. * uchino@ific.uv.es

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Heavy-quark spin symmetry for charmed and strange baryon resonances

Cited by 8 publications

References 25 publications

Combined large-Ncand heavy-quark operator analysis for the chiral Lagrangian with charmed baryons

Combined large-Ncand heavy-quark operator analysis for the chiral Lagrangian with charmed baryons

Baryon states with open charm in the extended local hidden gauge approach

Baryon states with hidden charm in the extended local hidden gauge approach

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