The observation of five
Ω
c
= ssc states by LHCb Aaij et al. Phys. Rev. Lett.
118
, 182001 (
2017
) and the confirmation of four of them by Belle Yelton et al. Phys. Rev. D
97
, 051102 (
2018
), may ...represent an important milestone in our understanding of the quark organization inside hadrons. By providing results for the spectrum of
Ω
c
baryons and predictions for their
Ξ
c
+
K
-
and
Ξ
c
′
+
K
-
decay amplitudes within an harmonic oscillator based model, we suggest a possible solution to the
Ω
c
quantum number puzzle and we extend our mass and decay width predictions to the
Ω
b
states. Finally, we discuss why the set of
Ω
c
(
b
)
baryons is the most suitable environment to test the validity of three-quark and quark–diquark effective degrees of freedom.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We perform a quantitative analysis of the bbb¯b¯ tetraquark decays into hidden- and open-bottom mesons and calculate, for the first time, the bbb¯b¯ tetraquark total decay width. On the basis of our ...results, we propose the bbb¯b¯→B+B−(B0B¯0)(Bs0B¯s0)→l+l−+X decays as the most suitable channels to observe the bbb¯b¯ tetraquark states, since the calculated two-lepton cross section upper limit, ≃39 fb, is so large as to be potentially detectable with the 2018 LHCb sensitivity, paving the way to the observation of the bbb¯b¯ tetraquark in the future LHCb upgrade. The 4μ signal for the ground state, JPC=0++, is likely to be too small even for the upgraded LHCb, but it may not be hopeless for the JPC=2++ fully-bottom state.
We perform a quantitative analysis of the decays of ccc¯c¯ tetraquarks with JPC=0++,2++ into 4 muons and into hidden- and open-charm mesons and estimate, for the first time, the fully charmed ...tetraquark decay width. The calculated cross section upper limit is ∼39(780) fb for the 4 muons channel, and ∼42(616) pb for the D(⁎)D¯(⁎)→eμ channel, in the 0++(2++) case. Decay widths depend upon the additional parameter ξ=|ΨT(0)|2/|ΨJ/ψ(0)|2, which can be computed with a considerable error. We find Γ(0++)∼Γ(2++)=97±30. On the basis of our results and with the present sensitivity, LHCb should detect both 0++ and 2++ fully-charmed tetraquarks.
Abstract
The observation of five
$$\varOmega _c $$
Ω
c
= ssc states by LHCb Aaij et al. Phys. Rev. Lett.
118
, 182001
(2017) and the confirmation of four of them by Belle Yelton et al. Phys. Rev. D
...97
, 051102
(2018), may represent an important milestone in our understanding of the quark organization inside hadrons. By providing results for the spectrum of
$$\varOmega _{ c}$$
Ω
c
baryons and predictions for their
$$\varXi _{ c}^{+}K^{-}$$
Ξ
c
+
K
-
and
$$\varXi _{ c}'^{+}K^{-}$$
Ξ
c
′
+
K
-
decay amplitudes within an harmonic oscillator based model, we suggest a possible solution to the
$$\varOmega _{c}$$
Ω
c
quantum number puzzle and we extend our mass and decay width predictions to the
$$\varOmega _b$$
Ω
b
states. Finally, we discuss why the set of
$$\varOmega _{ c(b)}$$
Ω
c
(
b
)
baryons is the most suitable environment to test the validity of three-quark and quark–diquark effective degrees of freedom.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Compact pentaquark states Giachino, A.; Santopinto, E.
EPJ Web of Conferences,
01/2018, Letnik:
192
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
We investigated the lightest pentaquark state observed by the LHCb collaboration as a compact five-quark ground-state, with spin
S
= 3/2, and we showed that this state belongs to a
SU
f
(3) flavor ...octet by means of a group theory approach. Moreover, we predicted in a parameter-free way the pentaquark state mass spectra for all the octet-pentaquark states. Finally, by means of an effective Lagrangian approach, we computed the octet-pentaquark partial decay widths in
J
/ψΛ,
J
/ψΣ and
J
/ψΞ channels.
Heavy Ωc and Ωb baryons in the quark model Ortiz-Pacheco, E.; Bijker, R.; García-Tecocoatzi, H. ...
Journal of physics. Conference series,
09/2020, Letnik:
1610, Številka:
1
Journal Article
Recenzirano
Odprti dostop
In this contribution, we present a study of ground- and excited-state Ωc and Ωb baryons consisting of two strange quarks and a heavy charm or bottom quark. An analysis in the quark model shows that ...the recently observed excited Ωc and Ωb states can be interpreted in terms of λ-mode excitations.
Abstract Our initial experience with mobile bearing medial compartment unicompartmental arthroplasty (UKA) is presented to highlight lessons that have been learned to avoid short-term failures. ...Consecutive cases of the Oxford medial UKA performed between February 2001 and April 2006 were reviewed to derive those cases that were revised to total knee arthroplasty (TKA). There were 545 patients available with mean age and body mass index of 65.0 and 30.1, respectively. At final follow-up, 32 patients were revised for lateral compartment arthritis, aseptic component loosening, persisting medial or anterior pain and dislocated meniscal bearing. Revisions were performed with primary unconstrained TKA implants with no stems or wedges required. Our results seem to reflect those seen in registries confirming an earlier higher revision rate and highlight the technical issues of overstuffing the compartment, inadequate cementation technique, and strict adherence to patient selection.
PDF
