Motivated by the newly observed narrow structures
Ω
b
(
6316
)
-
,
Ω
b
(
6330
)
-
,
Ω
b
(
6340
)
-
, and
Ω
b
(
6350
)
-
in the
Ξ
b
0
K
-
mass spectrum, we investigate the strong decays of the ...low-lying
Ω
b
states within the
3
P
0
model systematically. According to their masses and decay widths, the observed
Ω
b
(
6316
)
-
,
Ω
b
(
6330
)
-
,
Ω
b
(
6340
)
-
, and
Ω
b
(
6350
)
-
resonances can be reasonably assigned as the
λ
-
mode
Ω
b
(
1
P
)
states with
J
P
=
1
/
2
-
,
3
/
2
-
,
3
/
2
-
, and
5
/
2
-
. Meanwhile, the remaining
P
-
wave state with
J
P
=
1
/
2
-
should have a rather broad width, which can hardly be observed by experiments. For the
Ω
b
(
2
S
)
and
Ω
b
(
1
D
)
states, our predictions show that these states have relatively narrow total widths and mainly decay into the
Ξ
b
K
¯
,
Ξ
b
′
K
¯
and
Ξ
b
′
∗
K
¯
final states. These abundant theoretical predictions may be valuable for searching more excited
Ω
b
states in future experiments.
Inspired by recent measurement of possible fully charmed tetraquarks in LHCb Collaboration, we investigate the mass spectra of fully heavy tetraquarks
Q
Q
Q
¯
Q
¯
in an extended relativized quark ...model. Our estimations indicate that the broad structure around 6.4 GeV should contain one or more ground states for
c
c
c
¯
c
¯
tetraquarks, while the narrow structure near 6.9 GeV can be categorized as the first radial excitation of
c
c
c
¯
c
¯
system. Moreover, with the wave functions of the tetraquarks and mesons, the strong decays of tetraquarks into heavy quarkonium pair are qualitatively discussed, which can be further checked by the LHCb and CMS Collaborations.
We study the mass spectra and radiative decays of doubly heavy baryons within the diquark picture in a relativized quark model. The mass of the JP=1/2+ Ξcc ground state is predicted to be 3606 MeV, ...which is consistent with the mass of Ξcc++(3621) newly observed by the LHCb Collaboration. The predicted mass gap between two S-wave states, Ξcc* (JP=3/2+) and Ξcc (JP=1/2+), is 69 MeV. Furthermore, the radiative transitions of doubly heavy baryons are also estimated by using the realistic wave functions obtained from relativized quark model. The radiative decay widths of Ξcc*++→Ξcc++γ and Ξcc*+→Ξcc+γ are predicted to be about 7 and 4 keV, respectively. These predictions of doubly heavy baryons can provide helpful information for future experimental searches.
We investigate the masses of csc¯s¯ tetraquark states in a diquark-antidiquark picture employing the relativized quark model proposed by Godfrey and Isgur. Only the antitriplet diquark states in ...color space are calculated. The diquark masses are obtained with the relativized potential first, and then the diquark and antidiquark are treated as the usual antiquark and quark, respectively, and the masses of the tetraquark states are obtained by solving the Schrödinger equation with the relativized potential between the diquark and antidiquark. The theoretical uncertainties induced by screening effects are also taken into account. It is found that the resonance of X(4140) can be regarded as the csc¯s¯ tetraquark ground states, and the X(4700) can be assigned as the 2S excited tetraquark state. When the internal excited diquarks are taken into account, the resonance of X(4500) can be explained as the tetraquark composed of one 2S scalar diquark and one scalar antidiquark. In our approach, the X(4274) cannot be explained as a tetraquark state; however, it can be a good candidate of the conventional χc1(3P31) state. In addition, other charmoniumlike states χc0(3915), X(4350), X(4630), and X(4660), as the csc¯s¯ tetraquark states, are also discussed.
Three neutral resonances
Ξ
c
(
2923
)
0
,
Ξ
c
(
2939
)
0
, and
Ξ
c
(
2965
)
0
have been observed in the
Λ
c
+
K
-
mass spectrum by the LHCb Collaboration. Given the
Ξ
c
and
Ξ
c
′
mass spectra ...predicted by the constituent quark models, these three resonances are tentatively treated as the
λ
-mode
Ξ
c
(
2
S
)
,
Ξ
c
′
(
2
S
)
,
Ξ
c
′
∗
(
2
S
)
, and
Ξ
c
′
(
1
P
)
states, and their strong decay behaviors are calculated within the
3
P
0
model. Our results indicate that the
Ξ
c
(
2923
)
0
and
Ξ
c
(
2939
)
0
can be clarified into the
J
P
=
3
/
2
-
and
5
/
2
-
Ξ
c
′
(
1
P
)
states respectively, and the
Ξ
c
(
2965
)
0
can be regarded as the
J
P
=
1
/
2
+
Ξ
c
′
(
2
S
)
state. Also, we suggest that the previous observed
Ξ
c
(
2930
)
may be the overlap of two structures
Ξ
c
(
2923
)
and
Ξ
c
(
2939
)
, and the
Ξ
c
(
2970
)
should be the same state as
Ξ
c
(
2965
)
. Other theoretical information on the missing
Ξ
c
(
2
S
)
,
Ξ
c
′
∗
(
2
S
)
, and
Ξ
c
′
(
1
P
)
states may be helpful for future experimental searches.
In this work we systematically calculate the mass spectra of open charm and bottom tetraquarks qqq Q within an extended relativized quark model. The four-body relativized Hamiltonians including the ...Coulomb potential, confining potential, spin-spin interactions, and relativistic corrections are solved by using the variational method. We find that the predicted masses of four 0+ uds c states are 2765, 3065, 3152, and 3396 MeV, which disfavor the assignment of the newly observed X0(2900) as a compact tetraquark. Moreover, the mass spectra of the open charm and bottom tetraquarks show quite similar patterns, which preserve the light flavor SU(3) symmetry and heavy quark symmetry well. In addition, our results suggest that the flavor-exotic states nns c, nns b, ssn c, and ssn b and their antiparticles can be searched for in the heavy-light meson plus kaon final states by future experiments. More theoretical and experimental efforts are needed to investigate these singly heavy tetraquarks.
Using the newly measured masses of Bc(1S) and Bc(2S) from the CMS Collaboration and the 1S hyperfine splitting determined from the lattice QCD as constraints, we calculate the Bc mass spectrum up to ...the 6S multiplet with a nonrelativistic linear potential model. Furthermore, using the wave functions from this model we calculate the radiative transitions between the Bc states within a constituent quark model. For the higher mass Bc states lying above DB threshold, we also evaluate the Okubo-Zweig-Iizuka (OZI) allowed two-body strong decays with the 3P0 model. Our study indicates that there is large potential for the observations of the low-lying Bc states below the DB threshold via their radiative transitions; in addition, some higher mass Bc states, such as Bc(23P2), Bc(23D1), Bc(33D1), Bc(43P0), and the 1F-wave Bc states, might be first observed in their dominant strong decay channels DB, DB*, or D*B at the LHC for their relatively narrow widths.
Inspired by the new resonance
Y
(10750), we calculate the masses and two-body OZI-allowed strong decays of the higher vector bottomonium sates within both screened and linear potential models. We ...discuss the possibilities of
Υ
(
10860
)
and
Y
(10750) as mixed states via the
S
-
D
mixing. Our results suggest that
Y
(10750) and
Υ
(
10860
)
might be explained as mixed states between 5
S
- and 4
D
-wave vector
b
b
¯
states. The
Y
(10750) and
Υ
(
10860
)
resonances may correspond to the mixed states dominated by the 4
D
- and 5
S
-wave components, respectively. The mass and the strong decay behaviors of the
Υ
(
11020
)
resonance are consistent with the assignment of the
Υ
(
6
S
)
state in the potential models.
Mutations of KRAS, NRAS, BRAF and DNA mismatch repair (MMR) status have become an important part of the assessment of patients with colorectal cancer (CRC), while respective clinicopathologic ...features and prognostic significance in specific stages and related detection strategies remain unclear. We retrospectively analyzed clinicopathologic features and prognosis of 1,834 patients with Stage I–IV colorectal adenocarcinoma. Mutations in KRAS, NRAS and BRAF and DNA MMR status were determined. The mutation rates of KRAS, NRAS and BRAF were 46.4, 3.2 and 3.5%, respectively, and the mismatch repair gene deletion (dMMR) rate was 5.6%. In a multivariate analysis, female, advanced age, tumor type histology, mucinous carcinoma and positive tumor deposits were associated with a high KRAS mutation rate. A high BRAF mutation rate was associated with female, poor differentiation, lymphovascular invasion and positive tumor deposits. Factors associated with high dMMR rates included low age, large tumor size, poor differentiation, Stages I–III. Tumor site was independently associated with KRAS mutation, BRAF mutation and dMMR. KRAS and BRAF mutations were independent risk factors for shorter overall survival (OS) in Stage IV tumors but not in Stage I–III tumors. NRAS mutation was an independent risk factor for shorter OS in Stage I–II tumors. dMMR was independently associated with longer OS in Stage III tumors.
What's new?
Mutations in KRAS, NRAS, BRAF and DNA mismatch repair (MMR) status are important biomarkers in the assessment of patients with colorectal cancer (CRC). However, the clinicopathologic features associated with these mutations—and their impact on prognosis—are unclear, especially at earlier stages of CRC. In this large Chinese study, the authors analyzed variables such as gender, age, tumor histology, lymphovascular invasion, etc., that were associated with particular oncogene mutations and overall survival. These results should provide guidance for improved clinical strategies and enhance the usefulness of these biomarkers.
In this work, we study the mass spectra of the all-heavy tetraquark systems, i.e., ccc¯c¯, bbb¯b¯, bbc¯c¯/ccb¯b¯, bcc¯c¯/ccb¯c¯, bcb¯b¯/bbb¯c¯, and bcb¯c¯, within a potential model by including the ...linear confining potential, Coulomb potential, and spin-spin interactions. It shows that the linear confining potential has important contributions to the masses and is crucial for our understanding of the mass spectra of the all-heavy tetraquark systems. For the all-heavy tetraquarks Q1Q2Q¯3Q¯4, our explicit calculations suggest that no bound states can be formed below the thresholds of any meson pairs (Q1Q¯3) − (Q2Q¯4) or (Q1Q¯4) − (Q2Q¯3). Thus, we do not expect narrow all-heavy tetraquark states to be existing in experiments.
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