This is essentially an update of Ref. [1] [H. Y. Cheng, Int. J. Mod. Phys. A 24 （Suppl. 1）, 593 （2009）], a review of charmed baryon physics around 2007. Topics covered in this review include the spectroscopy, stro...This is essentially an update of Ref. [1] [H. Y. Cheng, Int. J. Mod. Phys. A 24 （Suppl. 1）, 593 （2009）], a review of charmed baryon physics around 2007. Topics covered in this review include the spectroscopy, strong decays, lifetimes, nonleptonic and semileptonic weak decays, and electromagnetic decays of charmed baryons.展开更多
CHARMED BARYONS Revised March 2012 by C.G. Wohl （LBNL）. There are 17 known charmed baryons, and four other candidates not well enough established to be promoted to the Summary Tables.＊ Fig. l（a） shows the mass sp...CHARMED BARYONS Revised March 2012 by C.G. Wohl （LBNL）. There are 17 known charmed baryons, and four other candidates not well enough established to be promoted to the Summary Tables.＊ Fig. l（a） shows the mass spectrum,展开更多
The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, Ξ;and Ξ;, which should be...The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, Ξ;and Ξ;, which should be helpful for experimental searches for these particles. The long-distance contributions are first studied in the doubly heavy baryon decays, and found to be significantly enhanced. Comparing all the processes, Ξ;→Λ;K;π;π;andΞ;π;are the most favorable decay modes for experiments to search for doubly heavy baryons.展开更多
A search for the doubly charmed baryon ?cc+ with the decay mode c Ω_(cc)^(+)→ Ξc+K-π+ is performed using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment from 2016...A search for the doubly charmed baryon ?cc+ with the decay mode c Ω_(cc)^(+)→ Ξc+K-π+ is performed using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of 5.4 fb-1. No significant signal is observed within the invariant mass range of 3.6 to 4.0 GeV/c2. Upper limits are set on the ratio R of the production cross-section times the total branching fraction of the Ω_(cc)^(+)→ Ξc+K-π+ decay with respect to the Ξcc++→ Λc+K-π+π+ decay. Upper limits at 95% credibility level for R in the range 0.005 to 0.11 are obtained for diferent hypotheses on the ?cc+ mass and lifetime in the rapidity range from 2.0 to 4.5 and transverse momentum range from 4 to 15 GeV/c.展开更多
A search for the doubly charmed baryon ■^+cc is performed through its decay to theΛ^+c K^-π^+ final state,using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7,8 and 13...A search for the doubly charmed baryon ■^+cc is performed through its decay to theΛ^+c K^-π^+ final state,using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7,8 and 13 TeV.The data correspond to a total integrated luminosity of 9 fb^-1.No significant signal is observed in the mass range from 3.4 to 3.8 GeV/c^2.Upper limits are set at 95%credibility level on the ratio of the ■^+cc production cross-section times the branching fraction to that ofΛ^+c and ■^++cc baryons.The limits are determined as functions of the ■^+cc mass for different lifetime hypotheses,in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 4 to 15 GeV/c.展开更多
We propose to measure the decay asymmetry parameters in the hadronic weak decays of singly charmed baryons, such as Λc^＋ →Λπ^＋, Σ^0π^＋, pK0, Ξ0c →Ξ-π＋and Ω^0c →Ω^-π^＋. The joint angular formulae for...We propose to measure the decay asymmetry parameters in the hadronic weak decays of singly charmed baryons, such as Λc^＋ →Λπ^＋, Σ^0π^＋, pK0, Ξ0c →Ξ-π＋and Ω^0c →Ω^-π^＋. The joint angular formulae for these processes are presented, and are used to extract the asymmetry parameters in e^＋e^-annihilation data. Base on the currentΛ＋c data set collected at BESIII, we estimate the experimental sensitivities to measure the parameters αΛπ＋forΛ＋c →Λπ＋, αΣ＋π0for Λc^＋ →Σ＋π^0 and αΣ0π＋for Λc^＋ →Σ^0π^＋.展开更多
We study charmed baryon resonances that are generated dynamically from a coupled-channel unitary approach that implements heavy-quark symmetry. Some states can already be identified with experimental observations, suc...We study charmed baryon resonances that are generated dynamically from a coupled-channel unitary approach that implements heavy-quark symmetry. Some states can already be identified with experimental observations, such as Ac（2595）, Ac（2660）, Ec（2902） or Ac（2941）, while others need a compilation of more experimental data as well as an extension of the model to include higher order contributions. We also compare our model to previous SU（4） schemes.展开更多
In this study,we investigate possible molecular states composed of two charmed strange baryons from theΞ_(c)^((′,∗))Ξ_(c)^((′,∗))interaction and their hidden-charm hidden-strange partners from theΞ_(c)^((′,∗))Ξ...In this study,we investigate possible molecular states composed of two charmed strange baryons from theΞ_(c)^((′,∗))Ξ_(c)^((′,∗))interaction and their hidden-charm hidden-strange partners from theΞ_(c)^((′,∗))Ξ¯_(c)^((′,∗))interaction.With the aid of heavy quark chiral effective Lagrangians,the interactions of charmed strange baryons are described with light meson exchanges.The potential kernels are constructed and inserted into the quasipotential Bethe–Salpeter equation.The bound states are produced from most interactions considered,which suggests that strong attractions exist widely between the charmed strange baryons.Experimental search for these types of molecular states is suggested in future high-precision measurements.展开更多
Up to now, the excited charmed and bottom baryon states have still not been well studied experimentally or theoretically. In this paper, we predict the mass of Ωb, the only L=0 baryon state which has not been observe...Up to now, the excited charmed and bottom baryon states have still not been well studied experimentally or theoretically. In this paper, we predict the mass of Ωb, the only L=0 baryon state which has not been observed, to be 6069.2 MeV. The spectra of charmed and bottom baryons with the orbital angular momentum L= 1 are studied in two popular constituent quark models, the Goldstone boson exchange （GBE） model and the one gluon exchange （OGE） hyperfine interaction model. Inserting the latest experimental data from the ＂Review of Particle Physics＂, we find that in the GBE model, there exist some multiplets （∑c（b）, ≡c（b） and Ωc（b）） in which the total spin of the three quarks in their lowest energy states is 3/2, but in the OGE model there is no such phenomenon. This is the most important difference between the GBE and OGE models. These results can be tested in the near future. We suggest more efforts to study the excited charmed and bottom baryons both theoretically and experimentally, not only for the abundance of baryon spectra, but also for determining which hyperfine interaction model best describes nature.展开更多
Compared with the charmed baryons, the bottom baryons are not very well known, either experimentally Or theoretically. In this paper, we investigate the dipion strong decays of the P-wave and D-wave excited bottom bar...Compared with the charmed baryons, the bottom baryons are not very well known, either experimentally Or theoretically. In this paper, we investigate the dipion strong decays of the P-wave and D-wave excited bottom baryons in the framework of the QPC model. We also extend the same analysis to the charmed baryons.展开更多
We report here the mass spectrum and magnetic moments of ccq（q ∈ u,d,s） systems in the potential model framework by assuming the inter-quark potential as the colour coulomb plus power form with power index ν varyi...We report here the mass spectrum and magnetic moments of ccq（q ∈ u,d,s） systems in the potential model framework by assuming the inter-quark potential as the colour coulomb plus power form with power index ν varying between 0.1 to 2.0.Here the two charm quarks are considered for the diquark states.The conventional one gluon exchange interaction has been employed to get the hyperfine and the fine structure between different states.We have predicted many low-lying states whose experimental verification can exclusively support the quark-diquark structure of the baryons.展开更多
The ＂good＂ diquark is employed to study A＋ baryons within a mass loaded flux tube model. The study indicates that all A＋ baryons candidates in the 2008 review by the Particle Data Group （PDG） are well described ...The ＂good＂ diquark is employed to study A＋ baryons within a mass loaded flux tube model. The study indicates that all A＋ baryons candidates in the 2008 review by the Particle Data Group （PDG） are well described in the mass loaded flux model. The quantum numbers JP of these A＋ candidates are assigned. If Ac（2765）＋ is an orbitally excited A＋, it is likely the JP=3/2＋one. If ∧c（2765）＋ is an orbitally excited ∑c, there ought to be another JP=3/2＋∧c＋with mass ≈2770 MeV. In the model, there exists no JP=1/2＋∧c＋（≈2700）predicted in existing literature. Ac （2940）＋ is very possible the orbitally excited baryon with展开更多
Possible structures and properties of some excited states of ∧^＋c dynamically generated in the coupled-channel P-wave meson-baryon scattering are studied by solving the Bethe-Salpeter（BS） equation in the framework...Possible structures and properties of some excited states of ∧^＋c dynamically generated in the coupled-channel P-wave meson-baryon scattering are studied by solving the Bethe-Salpeter（BS） equation in the framework of the Chiral Unitary Approach. It is shown that both ∧^＋c（2765） and ∧^＋c（2940） could be generated dynamically and could be compound states with multi-configuration molecular-like structures. The couplings of the generated states to various reaction channels are also calculated. Moreover, two highly excited states, ∧^＋c（3024） and ∧^＋c（3134）, are predicted.展开更多
The discovery of Ξ_(cc)^(++)has inspired new interest in studying doubly heavy baryons.In this study,the weak decays of a doubly charmed baryon B_(cc)to a light baryon B and a charm meson D^(*)(either a pseudoscalar ...The discovery of Ξ_(cc)^(++)has inspired new interest in studying doubly heavy baryons.In this study,the weak decays of a doubly charmed baryon B_(cc)to a light baryon B and a charm meson D^(*)(either a pseudoscalar or a vector one)are calculated.Following our previous work,we calculate the short distance contributions under the factorization hypothesis,whereas the long distance contributions are modeled as the final state interactions,which are calculated with the one particle exchange model.We find that the B_(cc)→BD^(*)decays'branching ratios are obviously larger,as they receive contributions of more polarization states.Among the decays that we investigate,the following have the largest branching fractions:BR(Ξ_(cc)^(++)→∑^(+)D^(*+))∈[0.46%,3.33%]estimated with τΞ_(cc)^(++)=256 fs;BR(Ξ_(cc)^(+)→AD^(*+))∈[0.38%,2.63%]and BR(Ξ_(cc)^(+)→∑^(0)D^(*+))∈[0.45%,3.16%]with τΞ_(cc)^(++)=45 fs;and BR(Ω_(cc)^(+)→Ξ^(0)D^(+))∈[0.27%,1.03%),BR(Ω_(cc)^(+)→∑^(0)D^(*+))∈[0.07%,0.44%],and BR(Ω_(cc)^(+)→∑^(0)D^(*+))∈[0.06%,0.45%] with τ_(Ω_(cc))^(+)=75 fs.By comparing the decay widths of pure color commensurate channels with those of pure bow-tie ones we find that the bow-tie mechanism plays an important role in charm decays.展开更多
If the number of colors N c is taken large,baryons and their excitations can be considered in a mean-field approach.We argue that the mean field in baryons breaks spontaneously the spherical and SU（3） flavor symmetr...If the number of colors N c is taken large,baryons and their excitations can be considered in a mean-field approach.We argue that the mean field in baryons breaks spontaneously the spherical and SU（3） flavor symmetries,but retains the SU（2） symmetry of simultaneous rotations in space and isospace.The one-quark and quark-hole excitations in the mean field,together with the SU（3） rotational bands about them determine the spectrum of baryon resonances,which turns out to be in good accordance with reality when one puts N c =3.A by-product of this scheme is a confirmation of the light pentaquark Θ ＋ baryon uudds as a typical Gamov–Teller resonance long known in nuclear physics.An extension of the same large-N c logic to charmed baryons leads to a prediction of a anti-decapenta （15）-plet of charmed pentaquarks,two of which,B ＋＋ c = cuuds and B ＋ c = cudds,may be light and stable with respect to strong decays.展开更多
Measurements of decay asymmetry parameters of charmed baryons,e.g.,Ξ0c,provide more data to test the W-emission and W-exchange mechanisms controlled by strong and weak interactions.Taking advantage of the spin polari...Measurements of decay asymmetry parameters of charmed baryons,e.g.,Ξ0c,provide more data to test the W-emission and W-exchange mechanisms controlled by strong and weak interactions.Taking advantage of the spin polarization in charmed baryon decays,we investigate the possibility to measure weak decay asymmetry parameters in the e^+e^-→Ξ0cΞ0c process.We analyze the transverse polarization spontaneously produced in this process and the spin transfer in the subsequent Ξc decays.The sensitivity to measure the asymmetry parameters is estimated for the decay Ξc→Ξ0π.展开更多
The Babar Collaboration announced two new excited charmed baryons c（3055）^＋ and c（3123）^＋. We study their strong decays assuming they are D-wave states. Some assignments are excluded by comparing our numerical...The Babar Collaboration announced two new excited charmed baryons c（3055）^＋ and c（3123）^＋. We study their strong decays assuming they are D-wave states. Some assignments are excluded by comparing our numerical results with the experimental values of the total widths of c（3055）^＋ and c（3123）^＋. We also suggest some possible decay modes, which will be helpful to determine the properties of c（3055）^＋ and c（3123）^＋.展开更多
We construct both the scalar-diquark-scalar-diquark-antiquark type and axialvector-diquark-axialvector-diquark-antiquark type interpolating currents to study the charmed pentaquark:states suscu with J^(p)=1/2^(±)...We construct both the scalar-diquark-scalar-diquark-antiquark type and axialvector-diquark-axialvector-diquark-antiquark type interpolating currents to study the charmed pentaquark:states suscu with J^(p)=1/2^(±).We employ the QCD sum rules to investigate the masses and pole residues of the charmed pentaquark states by taking into account the vacuum condensates up to dimension 13 in the operator product expansion.Our calculation results indicate that the scalar-diquark-scalar-diquark-antiquark type and axialvector-diquark-axialvector-diquark-antiquark type charmed pentaquark states suscu with J^(p)=1/2^(-) can be possible candidates of the excited states observed in the LHCb collaboration.展开更多
Without contamination from the final state interactions,the calculation of the branching ratios of semileptonic decays Ξ^((′))_(c)→Ξ+e^(+)ν_(e) may provide further information about the inner structure of charmed...Without contamination from the final state interactions,the calculation of the branching ratios of semileptonic decays Ξ^((′))_(c)→Ξ+e^(+)ν_(e) may provide further information about the inner structure of charmed baryons.Moreover,by studying such processes,one can better determine the form factors of Ξ_(c)→Ξ that can be further applied to relevant estimates.In this study,we used the light-front quark model to carry out computations where the three-body vertex functions forΞ_(c) and Ξ are employed.To fit the new data of the Belle II,we re-adjusted the model parameters to obtain β_(s[sq])=1.07 GeV,which is 2.9 times larger than β_(ss)=0.366 GeV.This value may imply that the ss pair in Ξ constitutes a more compact subsystem.Furthermore,we investigated the non-leptonic decays of Ξ^((′))_(c)→Ξ,which will be experimentally measured soon.Thus,our model will be tested in terms of consistency with the new data.展开更多
文摘This is essentially an update of Ref. [1] [H. Y. Cheng, Int. J. Mod. Phys. A 24 （Suppl. 1）, 593 （2009）], a review of charmed baryon physics around 2007. Topics covered in this review include the spectroscopy, strong decays, lifetimes, nonleptonic and semileptonic weak decays, and electromagnetic decays of charmed baryons.
文摘CHARMED BARYONS Revised March 2012 by C.G. Wohl （LBNL）. There are 17 known charmed baryons, and four other candidates not well enough established to be promoted to the Summary Tables.＊ Fig. l（a） shows the mass spectrum,
基金Supported by National Natural Science Foundation of China(11505083,11505098,11647310,11575110,11375208,11521505,11621131001,11235005,11447032,U1732101)Natural Science Foundation of Shanghai(15DZ2272100)
文摘The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, Ξ;and Ξ;, which should be helpful for experimental searches for these particles. The long-distance contributions are first studied in the doubly heavy baryon decays, and found to be significantly enhanced. Comparing all the processes, Ξ;→Λ;K;π;π;andΞ;π;are the most favorable decay modes for experiments to search for doubly heavy baryons.
基金Open Access funding provided by CERN(European Organization for Nuclear Research).
文摘A search for the doubly charmed baryon ?cc+ with the decay mode c Ω_(cc)^(+)→ Ξc+K-π+ is performed using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of 5.4 fb-1. No significant signal is observed within the invariant mass range of 3.6 to 4.0 GeV/c2. Upper limits are set on the ratio R of the production cross-section times the total branching fraction of the Ω_(cc)^(+)→ Ξc+K-π+ decay with respect to the Ξcc++→ Λc+K-π+π+ decay. Upper limits at 95% credibility level for R in the range 0.005 to 0.11 are obtained for diferent hypotheses on the ?cc+ mass and lifetime in the rapidity range from 2.0 to 4.5 and transverse momentum range from 4 to 15 GeV/c.
基金support from CERN and from the national agencies:CAPES,CNPq，FAPERJ and FINEP(Brazil)MOST and NSFC(China)+11 种基金CNRS/IN2P3(France)BMBF,DFG and MPG(Germany)INFN(Italy)KWO(Netherlands)MNiSW and NCN(Poland)MEN/IFA(Romania)MinES and FASO(Russia)MinECo(Spain)SNSF and SER(Switzerland)NASU(Ukraine)STFC(United Kingdom)NSF(USA).
文摘A search for the doubly charmed baryon ■^+cc is performed through its decay to theΛ^+c K^-π^+ final state,using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7,8 and 13 TeV.The data correspond to a total integrated luminosity of 9 fb^-1.No significant signal is observed in the mass range from 3.4 to 3.8 GeV/c^2.Upper limits are set at 95%credibility level on the ratio of the ■^+cc production cross-section times the branching fraction to that ofΛ^+c and ■^++cc baryons.The limits are determined as functions of the ■^+cc mass for different lifetime hypotheses,in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 4 to 15 GeV/c.
基金Supported by National Natural Science Foundation of China(11375205,11175146,11275266,11235011,11425524,11505010,11565006)Beijing Municipal Government Foundation(KM201610017009,2015000020124G064)Youth Innovation Promotion Association of CAS
文摘We propose to measure the decay asymmetry parameters in the hadronic weak decays of singly charmed baryons, such as Λc^＋ →Λπ^＋, Σ^0π^＋, pK0, Ξ0c →Ξ-π＋and Ω^0c →Ω^-π^＋. The joint angular formulae for these processes are presented, and are used to extract the asymmetry parameters in e^＋e^-annihilation data. Base on the currentΛ＋c data set collected at BESIII, we estimate the experimental sensitivities to measure the parameters αΛπ＋forΛ＋c →Λπ＋, αΣ＋π0for Λc^＋ →Σ＋π^0 and αΣ0π＋for Λc^＋ →Σ^0π^＋.
基金Supported by EU contract FLAVIAnet MRTN-CT-2006-035482, by the contract FIS2008-01143 from MEC (Spain) and FEDERby the Generalitat de Catalunya contract 2005SGR-00343, and the Junta de Andalucía grants FQM225, FQM481 and P06-FQM-01735This research is part of the EU Integrated Infrastructure Initiative Hadron Physics Project under contractnumber RII3-CT-2004-506078
文摘We study charmed baryon resonances that are generated dynamically from a coupled-channel unitary approach that implements heavy-quark symmetry. Some states can already be identified with experimental observations, such as Ac（2595）, Ac（2660）, Ec（2902） or Ac（2941）, while others need a compilation of more experimental data as well as an extension of the model to include higher order contributions. We also compare our model to previous SU（4） schemes.
基金Supported by the National Natural Science Foundation of China(11675228)。
文摘In this study,we investigate possible molecular states composed of two charmed strange baryons from theΞ_(c)^((′,∗))Ξ_(c)^((′,∗))interaction and their hidden-charm hidden-strange partners from theΞ_(c)^((′,∗))Ξ¯_(c)^((′,∗))interaction.With the aid of heavy quark chiral effective Lagrangians,the interactions of charmed strange baryons are described with light meson exchanges.The potential kernels are constructed and inserted into the quasipotential Bethe–Salpeter equation.The bound states are produced from most interactions considered,which suggests that strong attractions exist widely between the charmed strange baryons.Experimental search for these types of molecular states is suggested in future high-precision measurements.
基金Supported by National Natural Science Foundation of China(11175020,11575023,U1204115)
文摘Up to now, the excited charmed and bottom baryon states have still not been well studied experimentally or theoretically. In this paper, we predict the mass of Ωb, the only L=0 baryon state which has not been observed, to be 6069.2 MeV. The spectra of charmed and bottom baryons with the orbital angular momentum L= 1 are studied in two popular constituent quark models, the Goldstone boson exchange （GBE） model and the one gluon exchange （OGE） hyperfine interaction model. Inserting the latest experimental data from the ＂Review of Particle Physics＂, we find that in the GBE model, there exist some multiplets （∑c（b）, ≡c（b） and Ωc（b）） in which the total spin of the three quarks in their lowest energy states is 3/2, but in the OGE model there is no such phenomenon. This is the most important difference between the GBE and OGE models. These results can be tested in the near future. We suggest more efforts to study the excited charmed and bottom baryons both theoretically and experimentally, not only for the abundance of baryon spectra, but also for determining which hyperfine interaction model best describes nature.
基金Supported by National Natural Science Foundation of China(11222547,11175073,11035006,11375240,11261130311)Ministry of Education of China(FANEDD(200924)+2 种基金DPFIHE(20090211120029)NCET(NCET-10-0442)Fundamental Research Funds for Central Universities
文摘Compared with the charmed baryons, the bottom baryons are not very well known, either experimentally Or theoretically. In this paper, we investigate the dipion strong decays of the P-wave and D-wave excited bottom baryons in the framework of the QPC model. We also extend the same analysis to the charmed baryons.
基金the financial support from University Grant Commission,Government of India,under a Major Research Project F.32-31/2006(SR)
文摘We report here the mass spectrum and magnetic moments of ccq（q ∈ u,d,s） systems in the potential model framework by assuming the inter-quark potential as the colour coulomb plus power form with power index ν varying between 0.1 to 2.0.Here the two charm quarks are considered for the diquark states.The conventional one gluon exchange interaction has been employed to get the hyperfine and the fine structure between different states.We have predicted many low-lying states whose experimental verification can exclusively support the quark-diquark structure of the baryons.
基金Supported by National Natural Science Foundation of China (10775093)Shanghai Leading Academic Discipline Project(S30105)
文摘The ＂good＂ diquark is employed to study A＋ baryons within a mass loaded flux tube model. The study indicates that all A＋ baryons candidates in the 2008 review by the Particle Data Group （PDG） are well described in the mass loaded flux model. The quantum numbers JP of these A＋ candidates are assigned. If Ac（2765）＋ is an orbitally excited A＋, it is likely the JP=3/2＋one. If ∧c（2765）＋ is an orbitally excited ∑c, there ought to be another JP=3/2＋∧c＋with mass ≈2770 MeV. In the model, there exists no JP=1/2＋∧c＋（≈2700）predicted in existing literature. Ac （2940）＋ is very possible the orbitally excited baryon with
基金Supported by National Natural Science Foundation of China (10775147,10975038,11035006)
文摘Possible structures and properties of some excited states of ∧^＋c dynamically generated in the coupled-channel P-wave meson-baryon scattering are studied by solving the Bethe-Salpeter（BS） equation in the framework of the Chiral Unitary Approach. It is shown that both ∧^＋c（2765） and ∧^＋c（2940） could be generated dynamically and could be compound states with multi-configuration molecular-like structures. The couplings of the generated states to various reaction channels are also calculated. Moreover, two highly excited states, ∧^＋c（3024） and ∧^＋c（3134）, are predicted.
基金National Natural Science Foundation of China(11765012,12075126)。
文摘The discovery of Ξ_(cc)^(++)has inspired new interest in studying doubly heavy baryons.In this study,the weak decays of a doubly charmed baryon B_(cc)to a light baryon B and a charm meson D^(*)(either a pseudoscalar or a vector one)are calculated.Following our previous work,we calculate the short distance contributions under the factorization hypothesis,whereas the long distance contributions are modeled as the final state interactions,which are calculated with the one particle exchange model.We find that the B_(cc)→BD^(*)decays'branching ratios are obviously larger,as they receive contributions of more polarization states.Among the decays that we investigate,the following have the largest branching fractions:BR(Ξ_(cc)^(++)→∑^(+)D^(*+))∈[0.46%,3.33%]estimated with τΞ_(cc)^(++)=256 fs;BR(Ξ_(cc)^(+)→AD^(*+))∈[0.38%,2.63%]and BR(Ξ_(cc)^(+)→∑^(0)D^(*+))∈[0.45%,3.16%]with τΞ_(cc)^(++)=45 fs;and BR(Ω_(cc)^(+)→Ξ^(0)D^(+))∈[0.27%,1.03%),BR(Ω_(cc)^(+)→∑^(0)D^(*+))∈[0.07%,0.44%],and BR(Ω_(cc)^(+)→∑^(0)D^(*+))∈[0.06%,0.45%] with τ_(Ω_(cc))^(+)=75 fs.By comparing the decay widths of pure color commensurate channels with those of pure bow-tie ones we find that the bow-tie mechanism plays an important role in charm decays.
基金supported by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japanthe Japan Society for the Promotion of Science (JSPS)+29 种基金the Tau-Lepton Physics Research Center of Nagoya Universitythe Australian Research Council including grants DP180102629, DP170102389, DP170102204, DE220100462, DP150103061, FT130100303Austrian Federal Ministry of Education, Science and Research (FWF) and FWF Austrian Science Fund No. P 31361-N36the National Natural Science Foundation of China under Contracts No. 11675166, No. 11705209No. 11805064No. 11975076No. 12135005No. 12175041No. 12161141008Key Research Program of Frontier Sciences, Chinese Academy of Sciencess (CAS), Grant No. QYZDJ-SSW-SLH011the Shanghai Science and Technology Committee (STCSM) under Grant No. 19ZR1403000the Ministry of Education, Youth and Sports of the Czech Republic under Contract No. LTT17020the Czech Science Foundation Grant No. 22-18469SHorizon 2020 ERC Advanced Grant No. 884719 and ERC Starting Grant No. 947006 ‘‘Inter Leptons” (European Union)the Carl Zeiss Foundation, the Deutsche Forschungsgemeinschaft, the Excellence Cluster Universe, and the Volkswagen Stiftungthe Department of Atomic Energy (Project Identification No. RTI 4002)the Department of Science and Technology of Indiathe Istituto Nazionale di Fisica Nucleare of ItalyNational Research Foundation (NRF) of Korea Grant Nos. 2016R1D1A1B02012900, 2018R1A2B3003643, 2018R1A6A1A060 24970, RS202200197659, 2019R1I1A3A01058933, 2021R1A6A1A03043957, 2021R1F1A1060423, 2021R1F1A1064008, 2022R1A2C 1003993Radiation Science Research Institute, Foreign Large-size Research Facility Application Supporting projectthe Global Science Experimental Data Hub Center of the Korea Institute of Science and Technology Information and KREONET/GLORIADthe Polish Ministry of Science and Higher Education and the National Science Centerthe Ministry of Science and Higher Education of the Russian Federation, Agreement 14.W03.31.0026the HSE University Basic Research Program, MoscowUniversity of Tabuk research grants S-1440-0321, S-0256-1438, and S-0280-1439 (Saudi Arabia)the Slovenian Research Agency Grant Nos. J19124 and P1-0135Ikerbasque, Basque Foundation for Science, Spainthe Swiss National Science Foundationthe Ministry of Education and the Ministry of Science and Technology of Taiwanthe United States Department of Energy and the National Science Foundation。
基金Supported by Russian Government grant RFBR-09-02-01198Mercator Fellowship,DFG,Germany
文摘If the number of colors N c is taken large,baryons and their excitations can be considered in a mean-field approach.We argue that the mean field in baryons breaks spontaneously the spherical and SU（3） flavor symmetries,but retains the SU（2） symmetry of simultaneous rotations in space and isospace.The one-quark and quark-hole excitations in the mean field,together with the SU（3） rotational bands about them determine the spectrum of baryon resonances,which turns out to be in good accordance with reality when one puts N c =3.A by-product of this scheme is a confirmation of the light pentaquark Θ ＋ baryon uudds as a typical Gamov–Teller resonance long known in nuclear physics.An extension of the same large-N c logic to charmed baryons leads to a prediction of a anti-decapenta （15）-plet of charmed pentaquarks,two of which,B ＋＋ c = cuuds and B ＋ c = cudds,may be light and stable with respect to strong decays.
基金Supported by the National Natural Science Foundation of China(11875262,11805037,11705078)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(U1832121)+1 种基金Shanghai Pujiang Program(18PJ1401000)Open Research Program of Large Research Infrastructures(2017),Chinese Academy of Sciences
文摘Measurements of decay asymmetry parameters of charmed baryons,e.g.,Ξ0c,provide more data to test the W-emission and W-exchange mechanisms controlled by strong and weak interactions.Taking advantage of the spin polarization in charmed baryon decays,we investigate the possibility to measure weak decay asymmetry parameters in the e^+e^-→Ξ0cΞ0c process.We analyze the transverse polarization spontaneously produced in this process and the spin transfer in the subsequent Ξc decays.The sensitivity to measure the asymmetry parameters is estimated for the decay Ξc→Ξ0π.
基金National Natural Science Foundation of China(10421503,10625521,10705001)China Postdoctoral Science Foundation(20060400376)
文摘The Babar Collaboration announced two new excited charmed baryons c（3055）^＋ and c（3123）^＋. We study their strong decays assuming they are D-wave states. Some assignments are excluded by comparing our numerical results with the experimental values of the total widths of c（3055）^＋ and c（3123）^＋. We also suggest some possible decay modes, which will be helpful to determine the properties of c（3055）^＋ and c（3123）^＋.
基金supported by National Natural Science Foundation,Grant Number 11775079.
文摘We construct both the scalar-diquark-scalar-diquark-antiquark type and axialvector-diquark-axialvector-diquark-antiquark type interpolating currents to study the charmed pentaquark:states suscu with J^(p)=1/2^(±).We employ the QCD sum rules to investigate the masses and pole residues of the charmed pentaquark states by taking into account the vacuum condensates up to dimension 13 in the operator product expansion.Our calculation results indicate that the scalar-diquark-scalar-diquark-antiquark type and axialvector-diquark-axialvector-diquark-antiquark type charmed pentaquark states suscu with J^(p)=1/2^(-) can be possible candidates of the excited states observed in the LHCb collaboration.
基金the National Natural Science Foundation of China(NNSFC)(12075167,11975165,11675082,11735010,12035009,12075125)。
文摘Without contamination from the final state interactions,the calculation of the branching ratios of semileptonic decays Ξ^((′))_(c)→Ξ+e^(+)ν_(e) may provide further information about the inner structure of charmed baryons.Moreover,by studying such processes,one can better determine the form factors of Ξ_(c)→Ξ that can be further applied to relevant estimates.In this study,we used the light-front quark model to carry out computations where the three-body vertex functions forΞ_(c) and Ξ are employed.To fit the new data of the Belle II,we re-adjusted the model parameters to obtain β_(s[sq])=1.07 GeV,which is 2.9 times larger than β_(ss)=0.366 GeV.This value may imply that the ss pair in Ξ constitutes a more compact subsystem.Furthermore,we investigated the non-leptonic decays of Ξ^((′))_(c)→Ξ,which will be experimentally measured soon.Thus,our model will be tested in terms of consistency with the new data.
