The potential energy curves of X~1Σ~+, A~1Σ~+, C~1Σ~+, and B~1Π are calculated with high-level MRDCI method, and the calculated spectroscopic constants of those states are in good agreement with most recent experi...The potential energy curves of X~1Σ~+, A~1Σ~+, C~1Σ~+, and B~1Π are calculated with high-level MRDCI method, and the calculated spectroscopic constants of those states are in good agreement with most recent experimental data. On the basis of high precision PECs, the radiative processes of H~++ Be collisions are studied by using the fully quantum, optical potential and semiclassical methods in the energy ranges of 10-8eV/u–0.1 eV/u, and the radiative decay, the radiative charge transfer,and the radiative association cross-sections are computed. It is found that the radiative association process is dominant in the energy region of 10-8eV/u–0.02 eV/u, while radiative charge transfer becomes important at higher energies. Rich resonance structures are present in the radiative association and charge transfer cross-sections in the whole energy region considered, which result from the interaction between the quasi-bound rovibrational(J, v) states in the entrance channel with the final continuum state. Significant isotope effects have been found in the radiative decay processes of H~++ Be collisions.展开更多
We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between ...We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by these cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about 36°, the branching ratio for γ→ rq^- is found to be 8.2 × 10^-4 from color singlet contributions. The color octet contributions could be much larger than that of color singlet, depending on the estimate of the color octet matrix elements. This process may provide a new test for the color octet mechanism in nonrelativistic QCD.展开更多
There are some uncertain charazteristics of the Ds1（2536）, which deserves further discussion. Based on the assumption that the meson is constituted by c s, and belongs to T doublet （1^＋, 2^＋）, radiative decays ...There are some uncertain charazteristics of the Ds1（2536）, which deserves further discussion. Based on the assumption that the meson is constituted by c s, and belongs to T doublet （1^＋, 2^＋）, radiative decays Ds1（2536） → Ds（1968） ＋γ and Ds1（2536） → Ds^＊（2112） ＋ γ are studied in the CQM model The large branching ratios of them from our calculations not only indicate the process may be detected in the future experiments, but also can give a deep comprehension of the structure of it.展开更多
We perform the first lattice QCD study on the radiative decay of the scalar glueball to the vector mesonφin the quenched approximation.The calculations are carried out on three gauge ensembles with different lattice ...We perform the first lattice QCD study on the radiative decay of the scalar glueball to the vector mesonφin the quenched approximation.The calculations are carried out on three gauge ensembles with different lattice spacings,which enable us to do the continuum extrapolation.We first revisit the radiative J/ψdecay into the scalar glueball G and obtain the partial decay widthΓ(J/ψ→γG)=0.578(86)keV and the branching fraction Br(J/ψ→γG)=6.2(9)×10^(-3),which are in agreement with the previous lattice results.We then extend the similar calculation to the process G→γφand get the partial decay widthΓ(G→γφ)=0.074(47)keV,which implies that the combined branching fraction of J/ψ→γG→γγφis as small as O(10^(-9))such that this process is hardly detected by the BESⅢexperiment even with the large J/ψsample of O(10^(10)).With the vector meson dominance model,the two-photon decay width of the scalar glueball is estimated to beΓ(G→γγ)=0.53(46)e V,which results in a large stickiness S(G)~O(10^(4))of the scalar glueball by assuming the stickiness of f_(2)(1270)to be one.展开更多
Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢCollaborations.The radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framewo...Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢCollaborations.The radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by us.We compare our results with other theoretical studies and experimental data.The couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).The most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QCD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QCD sum rules.展开更多
We study the rare radiative dileptonlc decays B^0（Bs）→γe^＋e^- （e = e, μ） in the standard model By using the B meson wave function constrained by non-leptonic decays, the branching ratios turn out to be of the ...We study the rare radiative dileptonlc decays B^0（Bs）→γe^＋e^- （e = e, μ） in the standard model By using the B meson wave function constrained by non-leptonic decays, the branching ratios turn out to be of the order of 10^-9 for Bs→γe^＋e^-, γe^＋e^-, and 10^-10 for Bs→γe^＋e^-, γe^＋e^-. Based on the study, these decays are accessible at the near future LHC-b experiment, which are useful to determine the B（B,） wave function.展开更多
We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model.This study confirms the nonlocal feature of the hyperon weak radiative transition operators,which are domin...We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model.This study confirms the nonlocal feature of the hyperon weak radiative transition operators,which are dominated by the pole terms,and an overall self-consistent description of the available experimental data for the Cabibbofavored hyperon weak radiative decays is presented.It provides a natural mechanism for evading the Hara theorem,where sizeable parity-violating contributions can come from the intermediate orbital excitations.Cancellations between pole terms also explain the significant SU(3)flavor symmetry breaking manifested by the experimental data.We also discuss several interesting selection rules arising from either the electromagnetic or the weak interaction vertices.These features suggest nontrivial relations among various hyperon decays.展开更多
QCD theory predicts the existence of glueballs,but so far all experimental endeavors have failed to identify any such states.To remedy this discrepancy between QCD,which has proven to be a successful theory for strong...QCD theory predicts the existence of glueballs,but so far all experimental endeavors have failed to identify any such states.To remedy this discrepancy between QCD,which has proven to be a successful theory for strong interactions,and the failure of experimental searches for glueballs,one is tempted to accept the promising interpretation that the glueballs mix with regular qq states of the same quantum numbers.The lattice estimate of the masses of pure 0++ glueballs ranges from 1 to 2 GeV,which is the region of the f_(0)family.Thus many authors suggest that the f_(0) mesonic series is an ideal place to study possible mixtures of glueballs and qq.In this paper,following the strategy proposed by Close,Farrar and Li,we try to determine the fraction of glueball components inf_(0)mesons using the measured mass spectra and the branching ratios of J/ψ radiative decays intof_(0)mesons.Since the pioneering papers by Close et al.,more than 20 years have elapsed and more accurate measurements have been done by several experimental collaborations,so it is time to revisit this interesting topic using new data.We suppose f_(0)(500)and f_(0)(980)to be pure quark states,while for f_(0)(1370),f_(0)(1500)and f_(0)(1710),to fit both the experimental data of J/ψradiative decay and their mass spectra,glueball components are needed.Moreover,the mass of the pure 0++ glueball is phenomenologically determined.展开更多
Motivated by the experimental measurements of D0 radiative decay modes, we have proposed a model to study the D0→ K＊0γ decay, by establishing a link with D0→ K＊0V （V=ρ0, ω） decays through the vector meson dom...Motivated by the experimental measurements of D0 radiative decay modes, we have proposed a model to study the D0→ K＊0γ decay, by establishing a link with D0→ K＊0V （V=ρ0, ω） decays through the vector meson dominance hypothesis. In order to do this properly, we have used the Lagrangians from the local hidden gauge symmetry approach to account for Vγ conversion. As a result, we have found the branching ratio B[D0→ K＊0γ]=（1.55-3.44）×10-4, which is in fair agreement with the experimental values reported by the Belle and BaBar collaborations.展开更多
Using 20.3 fb^(-1)of e^(+)e^(-)annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESⅢdetector,we report on an improved search for the radiative leptonic decay D^(+)→γe^(+)ve.An upper limi...Using 20.3 fb^(-1)of e^(+)e^(-)annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESⅢdetector,we report on an improved search for the radiative leptonic decay D^(+)→γe^(+)ve.An upper limit on its partial branching fraction for photon energies E_(γ)>10 MeV was determined to be 1.2×10^(-5)at a 90%confidence level;this excludes most current theoretical predictions.A sophisticated deep learning approach,which includes thorough validation and is based on the Transformer architecture,was implemented to efficiently distinguish the signal from massive backgrounds.展开更多
We analyze the radiative leptonic Bc decay Bc^-→τ^vτ^-γ in the Standard Model and the two- Higgs-doublet model using the non-relativistic constituent quark model. The results confirm that this channel is experimen...We analyze the radiative leptonic Bc decay Bc^-→τ^vτ^-γ in the Standard Model and the two- Higgs-doublet model using the non-relativistic constituent quark model. The results confirm that this channel is experimentally promising in view of the large number of Bc mesons which are expected to be produced at future hadron facilities. We also find that this decay is sensitive to the parameters of the two-Higgs-doublet model, and it can be tested in future experiments.展开更多
We construct a formalism that describes the resonances decaying into four pseudoscalar meson final states.This method is fully covariant and can be directly applied to the partial-wave analysis of high statistical dat...We construct a formalism that describes the resonances decaying into four pseudoscalar meson final states.This method is fully covariant and can be directly applied to the partial-wave analysis of high statistical data.Two topologies of the process are considered:two intermediate resonances,each decaying into two final mesons,and cascade decay via three meson intermediate states.In particular,we consider the production of such states in the central collision reactions and in radiative J/ψ decay.展开更多
In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation a...In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation associated with the power expansion of O(∧_(QCD)/m_(c)).In our calculation,we adopt two different models of the D-meson distribution amplitudesφ^(+)_(D,Ⅰ)andφ^(+)_(DⅡ).Within the framework of QCD factorization as well as the dispersion relation,we evaluate the soft contribution up to the next-to-leading logarithmic accuracy and also consider the higher-twist contribution from the two-particle and three-particle distribution amplitudes.Finally,we find that all the sub-leading power contributions are significant atλd(μ0)354 MeV,and the next-to-leading power contributions lead to 143%inφ^(+)_(D,Ⅰ)and 120%inφ^(+)_(DⅡ)corrections to leading power vector form factors with Eγ=0.5 GeV.As the corrections from the higher-twist and local sub-leading power contributions are enhanced with increasing inverse moment,it is difficult to extract an appropriate inverse moment of the D-meson distribution amplitude.The predicted branching fractions are(1.88^(+0.36)_(0.29))×10^(-5)forφ^(+)_(D,Ⅰ)and(2.31^(+0.65)_(-0.54))×10^(-5)forφ^(+)_(DⅡ).展开更多
We report recent results on charmonium spectroscopy and decay from the CLEO-c experiment at the Cornell electrompositron storage ring accelerator, CESR. Most of the results are based on the analysis of 54 pb-1 of lumi...We report recent results on charmonium spectroscopy and decay from the CLEO-c experiment at the Cornell electrompositron storage ring accelerator, CESR. Most of the results are based on the analysis of 54 pb-1 of luminosity collected at the ψ（2S） resonance, corresponding to 27 M ψ（2S） decays. We concentrate on radiative decays of ψ（2S） and J/ψ, on two-body mesonic decay of XcJ, on hadronic decay of the he, and on higher multipoles in the two-photon cascade ψ（2S）→γχcJ, XcJ→γJ/ψ.展开更多
In this study,we investigate quasi-two-body B_((s))→K^(*)γ→Kπγ decays in the perturbative QCD approach.Two-meson distribution amplitudes are introduced to describe the final state interactions of the Kπpair,whic...In this study,we investigate quasi-two-body B_((s))→K^(*)γ→Kπγ decays in the perturbative QCD approach.Two-meson distribution amplitudes are introduced to describe the final state interactions of the Kπpair,which involve time-like form factors and Gegenbauer polynomials.We calculate the CP averaged branching ratios of the B_((s))→K^(*)γ→Kπγ decays.Our results are in agreement with newly updated data measured by Belle Ⅱ.This suggests that it is more appropriate to analyze these quasi-two-body B decays in the three-body framework than the two-body framework.We also predict direct CP asymmetries for the considered decay modes and find that A_CP(B_(u,d)→K^(*)γ→Kπγ) is small and less than 1% in magnitude,whereas A_CP(B_(s)→K^(*)γ→Kπγ)is larger and can reach a few percent.Our predictions can be tested in future B meson experiments.展开更多
A new ratiometric Boltzmann thermometry approach is presented for the narrow-line red-emitting bright phosphor Al_(0.993)Cr_(0.007)B_(4O6)N.It relies on thermalization between the two excited states^(2)E_(g)(^(2)G)and...A new ratiometric Boltzmann thermometry approach is presented for the narrow-line red-emitting bright phosphor Al_(0.993)Cr_(0.007)B_(4O6)N.It relies on thermalization between the two excited states^(2)E_(g)(^(2)G)and^(2)T_(1g)(^(2)G)of Cr^(3+)with an energy gap of 620 cm^(−1)for optimized thermometry at room temperature.It is shown that nonradiative coupling between these excited states is very fast,with rates in the order of severalµs^(−1).Due to the comparably slow radiative decay(k_(r)=0.033 ms^(−1))of the lowest excited^(2)E_(g)(^(2)G)state,the dynamic working range of this Boltzmann thermometer for the deep red spectral range is exceptionally wide,between<77 K and>873 K,even outperforming the classic workhorse example of Er^(3+).At temperatures above 340 K,also spectrally well-resolved broad-band emission due to the spin-allowed^(4)T_(2g)(^(4)F)→^(4)A_(2g)(^(4)F)transition is detectable,which simultaneously offers a possibility of very sensitive(S_(r)(500 K)>2%K^(−1))ratiometric Boltzmann-type crossover thermometry for higher temperatures.These findings imply that Al_(0.993)Cr_(0.007)B_(4)O_(6)N is a particularly robust and bright red luminescent thermometer with a record-breaking dynamic working range for a luminescent transition metal ion.展开更多
We present a study of the inclusive photon spectra from 5.9 million J/ψ decays collected with the KEDR detector at the VEPP-4M e＋e collider. We measure the branching fraction of radiative decay J/ψ→ηcγ, ηc widt...We present a study of the inclusive photon spectra from 5.9 million J/ψ decays collected with the KEDR detector at the VEPP-4M e＋e collider. We measure the branching fraction of radiative decay J/ψ→ηcγ, ηc width and mass. Our preliminary results are： M（ηc） = 2979.4± 1.5 ± 1.9 MeV/c^2, Г（ηc） = 27.8±5.1 ±3.3 MeV, B（Jψ→ηcγ） = （2.34±0.15±0.40）%.展开更多
We discuss a possible interpretation of the open charm mesons D＊s0 （2317）,D s1 （2460） and the hidden charm mesons X（3872）,Y（3940） and Y（4140） as hadron molecules.Using a phenomenological Lagrangian approach...We discuss a possible interpretation of the open charm mesons D＊s0 （2317）,D s1 （2460） and the hidden charm mesons X（3872）,Y（3940） and Y（4140） as hadron molecules.Using a phenomenological Lagrangian approach we review the strong and radiative decays of the D＊ s0 （2317） and D s1 （2460） states.The X（3872） is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration.Determing the radiative （γJ/ψ and γψ（2s）） and strong （J/ψ2π and J/ψ3π） decay modes we show that the present experimental observation is consistent with the molecular structure assumption of the X（3872）.Finally,we give evidence for molecular interpretations of the Y（3940） and Y（4140） related to the observed strong decay modes J/ψ＋ω or J/ψ＋φ,respectively.展开更多
The three lowest-lying r states,ie,r(1S),T(2S),and r(35),composed of b pairs and below the BB threshold,provide a good platform for the researches of hadronic physics and physics beyond the Standard Model.They can be ...The three lowest-lying r states,ie,r(1S),T(2S),and r(35),composed of b pairs and below the BB threshold,provide a good platform for the researches of hadronic physics and physics beyond the Standard Model.They can be produced directly in ete--colliding experiments,such as CLEO,Babar,and Belle,with low continuum backgrounds.In these experiments,many measurements of the exclusive r(1S)and r(2S)decays into light hadrons,which shed light on the"80%rule"for the Okubo-Zweig-lizuka suppressed decays in the bottomonium sector,were carried out.Meanwhile,many studies of the charmonium and bottomonium productions in r(1S,2S,3S)decays were performed,to distinguish different Quantum Chromodynamics(QCD)models.Besides,exotic states and new physics were also extensively explored in r(1S,2S,3S)decays at CLEO,BaBar,and Bell.The r(1S,2S,3S)states can also be produced in p collisions and in ollisions involving heavy ions.The precision measurements of their cross sections and polarizations at the large hadron collider(LHC),especially in the CMS,ATLAS,and LHCb experiments,help to understand r production mechanisms in Pp collisions.The observation of the sequential r suppession in heavy ion collisions at CMS,LHCb,and ALICE is of great importance for verifying the quark-gluon plasma predicted by QCD.In this article,we review the experimental results on T(1S,2S,3S)at e+e-colliders and the LHC,and summarize their prospects at Belle II and the LHC.展开更多
基金Project supported by the Natural Science Foundation of Heilongjiang Province of China(Grant No.A2015011)the Scientific Research Plan Projects of Heilongjiang Educational Department,China(Grant No.135209258)
文摘The potential energy curves of X~1Σ~+, A~1Σ~+, C~1Σ~+, and B~1Π are calculated with high-level MRDCI method, and the calculated spectroscopic constants of those states are in good agreement with most recent experimental data. On the basis of high precision PECs, the radiative processes of H~++ Be collisions are studied by using the fully quantum, optical potential and semiclassical methods in the energy ranges of 10-8eV/u–0.1 eV/u, and the radiative decay, the radiative charge transfer,and the radiative association cross-sections are computed. It is found that the radiative association process is dominant in the energy region of 10-8eV/u–0.02 eV/u, while radiative charge transfer becomes important at higher energies. Rich resonance structures are present in the radiative association and charge transfer cross-sections in the whole energy region considered, which result from the interaction between the quasi-bound rovibrational(J, v) states in the entrance channel with the final continuum state. Significant isotope effects have been found in the radiative decay processes of H~++ Be collisions.
基金The project supported in part by National Natural Science Foundation of China under Grant No. 10421503 and the Key Project of the Ministry of Education under Grant No. 305001, and the Research Found of Doctorial Programs of Higher Education of China. We thank E. Berger for bringing their earlier work on inelastic photoproduction of T （Ref. [12]） to our attention. We would also like to thank Ce Meng for valuable discussions.
文摘We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by these cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about 36°, the branching ratio for γ→ rq^- is found to be 8.2 × 10^-4 from color singlet contributions. The color octet contributions could be much larger than that of color singlet, depending on the estimate of the color octet matrix elements. This process may provide a new test for the color octet mechanism in nonrelativistic QCD.
基金Supported by National Natural Science Foundation of China under Grant No.10847117 Hebei Province Department of Education under Grant No.2007409 Doctor Foundation of Hebei University under Grant No.Y2006081
文摘There are some uncertain charazteristics of the Ds1（2536）, which deserves further discussion. Based on the assumption that the meson is constituted by c s, and belongs to T doublet （1^＋, 2^＋）, radiative decays Ds1（2536） → Ds（1968） ＋γ and Ds1（2536） → Ds^＊（2112） ＋ γ are studied in the CQM model The large branching ratios of them from our calculations not only indicate the process may be detected in the future experiments, but also can give a deep comprehension of the structure of it.
基金supported by the National Natural Science Foundation of China(Grant Nos.12175063,12175073,12222503,11935017,12293060,12293062,12293065,and 12070131001)(CRC 110 by DFG and NSFC)supported by the Natural Science Foundation of Basic and Applied Basic Research of Guangdong Province(Grant No.2023A1515012712)+4 种基金the support by the National Key Research and Development Program of China(Grant No.2020YFA0406400)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB34030302)the support by the Hunan Provincial Natural Science Foundation(Grant No.2023JJ30380)the support by the Hunan Provincial Natural Science Foundation(Grant No.2024JJ6300)the Scientific Research Fund of Hunan Provincial Education Department(Grant No.22B0044)。
文摘We perform the first lattice QCD study on the radiative decay of the scalar glueball to the vector mesonφin the quenched approximation.The calculations are carried out on three gauge ensembles with different lattice spacings,which enable us to do the continuum extrapolation.We first revisit the radiative J/ψdecay into the scalar glueball G and obtain the partial decay widthΓ(J/ψ→γG)=0.578(86)keV and the branching fraction Br(J/ψ→γG)=6.2(9)×10^(-3),which are in agreement with the previous lattice results.We then extend the similar calculation to the process G→γφand get the partial decay widthΓ(G→γφ)=0.074(47)keV,which implies that the combined branching fraction of J/ψ→γG→γγφis as small as O(10^(-9))such that this process is hardly detected by the BESⅢexperiment even with the large J/ψsample of O(10^(10)).With the vector meson dominance model,the two-photon decay width of the scalar glueball is estimated to beΓ(G→γγ)=0.53(46)e V,which results in a large stickiness S(G)~O(10^(4))of the scalar glueball by assuming the stickiness of f_(2)(1270)to be one.
基金Supported by Ho Chi Minh City University of Technology and Education(T2022-26)。
文摘Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢCollaborations.The radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by us.We compare our results with other theoretical studies and experimental data.The couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).The most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QCD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QCD sum rules.
基金The project supported by National Natural Science Foundation of China under Grant No. 10475085 and the Natural Science Foundation of Hebei Province of China under Grant No. A2005000535
文摘We study the rare radiative dileptonlc decays B^0（Bs）→γe^＋e^- （e = e, μ） in the standard model By using the B meson wave function constrained by non-leptonic decays, the branching ratios turn out to be of the order of 10^-9 for Bs→γe^＋e^-, γe^＋e^-, and 10^-10 for Bs→γe^＋e^-, γe^＋e^-. Based on the study, these decays are accessible at the near future LHC-b experiment, which are useful to determine the B（B,） wave function.
基金Supported by the National Natural Science Foundation of China(11425525,11521505)DFG and NSFC funds to the Sino-German CRC 110“Symmetries and the Emergence of Structure in QCD”(NSFC)(11261130311)+3 种基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB34030302)National Key Basic Research Program of China(2015CB856700)supported by the research startup funding at SCNU,Guangdong Provincial funding with(2019QN01X172)Science and Technology Program of Guangzhou(2019050001)。
文摘We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model.This study confirms the nonlocal feature of the hyperon weak radiative transition operators,which are dominated by the pole terms,and an overall self-consistent description of the available experimental data for the Cabibbofavored hyperon weak radiative decays is presented.It provides a natural mechanism for evading the Hara theorem,where sizeable parity-violating contributions can come from the intermediate orbital excitations.Cancellations between pole terms also explain the significant SU(3)flavor symmetry breaking manifested by the experimental data.We also discuss several interesting selection rules arising from either the electromagnetic or the weak interaction vertices.These features suggest nontrivial relations among various hyperon decays.
基金Supported by National Natural Science Foundation of China(11805160,11747040,11675082,11605039)。
文摘QCD theory predicts the existence of glueballs,but so far all experimental endeavors have failed to identify any such states.To remedy this discrepancy between QCD,which has proven to be a successful theory for strong interactions,and the failure of experimental searches for glueballs,one is tempted to accept the promising interpretation that the glueballs mix with regular qq states of the same quantum numbers.The lattice estimate of the masses of pure 0++ glueballs ranges from 1 to 2 GeV,which is the region of the f_(0)family.Thus many authors suggest that the f_(0) mesonic series is an ideal place to study possible mixtures of glueballs and qq.In this paper,following the strategy proposed by Close,Farrar and Li,we try to determine the fraction of glueball components inf_(0)mesons using the measured mass spectra and the branching ratios of J/ψ radiative decays intof_(0)mesons.Since the pioneering papers by Close et al.,more than 20 years have elapsed and more accurate measurements have been done by several experimental collaborations,so it is time to revisit this interesting topic using new data.We suppose f_(0)(500)and f_(0)(980)to be pure quark states,while for f_(0)(1370),f_(0)(1500)and f_(0)(1710),to fit both the experimental data of J/ψradiative decay and their mass spectra,glueball components are needed.Moreover,the mass of the pure 0++ glueball is phenomenologically determined.
基金funding agency FAPESP for the financial support(2016/22561-2)the Programa Santiago Grisolia of Generalitat Valenciana(Exp.GRISOLIA/2015/005)+3 种基金partly supported by the Spanish Ministerio de Economiay Competitividad and European FEDER funds(FIS2014-57026-REDT,FIS2014-51948-C2-1-P,FIS2014-51948-C2-2-P)the Generalitat Valenciana in the program Prometeo II-2014/068partly supported by the National Natural Science Foundation of China(11475227,11735003)the Youth Innovation Promotion Association CAS(2016367)
文摘Motivated by the experimental measurements of D0 radiative decay modes, we have proposed a model to study the D0→ K＊0γ decay, by establishing a link with D0→ K＊0V （V=ρ0, ω） decays through the vector meson dominance hypothesis. In order to do this properly, we have used the Lagrangians from the local hidden gauge symmetry approach to account for Vγ conversion. As a result, we have found the branching ratio B[D0→ K＊0γ]=（1.55-3.44）×10-4, which is in fair agreement with the experimental values reported by the Belle and BaBar collaborations.
基金supported in part by National Key R&D Program of China(2020YFA0406400,2023YFA1606000,2020YFA0406300)National Natural Science Foundation of China(NSFC)(11635010,11735014,11935015,11935016,11935018,12025502,12035009,12035013,12061131003,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017,12361141819)+18 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Programthe CAS Center for Excellence in Particle Physics(CCEPP)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(U1832207)CAS(YSBR-101)100 Talents Program of CASCAS Project for Young Scientists in Basic Research(YSBR-117)The Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and CosmologyAgencia Nacional de Investigación y Desarrollo de Chile(ANID),Chile(ANID PIA/APOYO AFB230003)German Research Foundation DFG(FOR5327)Istituto Nazionale di Fisica Nucleare,ItalyKnut and Alice Wallenberg Foundation(2021.0174,2021.0299)Ministry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF-2022R1A2C1092335)National Science and Technology fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation of Thailand(B50G670107)Polish National Science Centre(2019/35/O/ST2/02907)Swedish Research Council(2019.04595)The Swedish Foundation for International Cooperation in Research and Higher Education(CH2018-7756)U.S.Department of Energy(DE-FG02-05ER41374)。
文摘Using 20.3 fb^(-1)of e^(+)e^(-)annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESⅢdetector,we report on an improved search for the radiative leptonic decay D^(+)→γe^(+)ve.An upper limit on its partial branching fraction for photon energies E_(γ)>10 MeV was determined to be 1.2×10^(-5)at a 90%confidence level;this excludes most current theoretical predictions.A sophisticated deep learning approach,which includes thorough validation and is based on the Transformer architecture,was implemented to efficiently distinguish the signal from massive backgrounds.
基金Supported by National Natural Science Foundation of China (10675022,10975018)
文摘We analyze the radiative leptonic Bc decay Bc^-→τ^vτ^-γ in the Standard Model and the two- Higgs-doublet model using the non-relativistic constituent quark model. The results confirm that this channel is experimentally promising in view of the large number of Bc mesons which are expected to be produced at future hadron facilities. We also find that this decay is sensitive to the parameters of the two-Higgs-doublet model, and it can be tested in future experiments.
文摘We construct a formalism that describes the resonances decaying into four pseudoscalar meson final states.This method is fully covariant and can be directly applied to the partial-wave analysis of high statistical data.Two topologies of the process are considered:two intermediate resonances,each decaying into two final mesons,and cascade decay via three meson intermediate states.In particular,we consider the production of such states in the central collision reactions and in radiative J/ψ decay.
基金Supported in part by the National Natural Science Foundation of China(1675082,11735010)the Natural Science Foundation of Tianjin(19JCJQJC61100)。
文摘In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation associated with the power expansion of O(∧_(QCD)/m_(c)).In our calculation,we adopt two different models of the D-meson distribution amplitudesφ^(+)_(D,Ⅰ)andφ^(+)_(DⅡ).Within the framework of QCD factorization as well as the dispersion relation,we evaluate the soft contribution up to the next-to-leading logarithmic accuracy and also consider the higher-twist contribution from the two-particle and three-particle distribution amplitudes.Finally,we find that all the sub-leading power contributions are significant atλd(μ0)354 MeV,and the next-to-leading power contributions lead to 143%inφ^(+)_(D,Ⅰ)and 120%inφ^(+)_(DⅡ)corrections to leading power vector form factors with Eγ=0.5 GeV.As the corrections from the higher-twist and local sub-leading power contributions are enhanced with increasing inverse moment,it is difficult to extract an appropriate inverse moment of the D-meson distribution amplitude.The predicted branching fractions are(1.88^(+0.36)_(0.29))×10^(-5)forφ^(+)_(D,Ⅰ)and(2.31^(+0.65)_(-0.54))×10^(-5)forφ^(+)_(DⅡ).
文摘We report recent results on charmonium spectroscopy and decay from the CLEO-c experiment at the Cornell electrompositron storage ring accelerator, CESR. Most of the results are based on the analysis of 54 pb-1 of luminosity collected at the ψ（2S） resonance, corresponding to 27 M ψ（2S） decays. We concentrate on radiative decays of ψ（2S） and J/ψ, on two-body mesonic decay of XcJ, on hadronic decay of the he, and on higher multipoles in the two-photon cascade ψ（2S）→γχcJ, XcJ→γJ/ψ.
基金Supported in part by the National Natural Science Foundation of China under(11347030)the Program of Science and Technology Innovation Talents in Universities of Henan Province(14HASTIT037)。
文摘In this study,we investigate quasi-two-body B_((s))→K^(*)γ→Kπγ decays in the perturbative QCD approach.Two-meson distribution amplitudes are introduced to describe the final state interactions of the Kπpair,which involve time-like form factors and Gegenbauer polynomials.We calculate the CP averaged branching ratios of the B_((s))→K^(*)γ→Kπγ decays.Our results are in agreement with newly updated data measured by Belle Ⅱ.This suggests that it is more appropriate to analyze these quasi-two-body B decays in the three-body framework than the two-body framework.We also predict direct CP asymmetries for the considered decay modes and find that A_CP(B_(u,d)→K^(*)γ→Kπγ) is small and less than 1% in magnitude,whereas A_CP(B_(s)→K^(*)γ→Kπγ)is larger and can reach a few percent.Our predictions can be tested in future B meson experiments.
基金support by the“Young College”of the North-Rhine Westphalian Academy of Science,Humanities,and the Arts.Generous funding by the German National Science Foundation(DFG,SU 1156/5-1,project no.554302036)and the Strategic Research Fund of the HHU Düsseldorf is also gratefully acknowledged.
文摘A new ratiometric Boltzmann thermometry approach is presented for the narrow-line red-emitting bright phosphor Al_(0.993)Cr_(0.007)B_(4O6)N.It relies on thermalization between the two excited states^(2)E_(g)(^(2)G)and^(2)T_(1g)(^(2)G)of Cr^(3+)with an energy gap of 620 cm^(−1)for optimized thermometry at room temperature.It is shown that nonradiative coupling between these excited states is very fast,with rates in the order of severalµs^(−1).Due to the comparably slow radiative decay(k_(r)=0.033 ms^(−1))of the lowest excited^(2)E_(g)(^(2)G)state,the dynamic working range of this Boltzmann thermometer for the deep red spectral range is exceptionally wide,between<77 K and>873 K,even outperforming the classic workhorse example of Er^(3+).At temperatures above 340 K,also spectrally well-resolved broad-band emission due to the spin-allowed^(4)T_(2g)(^(4)F)→^(4)A_(2g)(^(4)F)transition is detectable,which simultaneously offers a possibility of very sensitive(S_(r)(500 K)>2%K^(−1))ratiometric Boltzmann-type crossover thermometry for higher temperatures.These findings imply that Al_(0.993)Cr_(0.007)B_(4)O_(6)N is a particularly robust and bright red luminescent thermometer with a record-breaking dynamic working range for a luminescent transition metal ion.
基金Supported by the Russian Foundation for Basic Research,grants 08-02-00258,08-02-00258RF Presidential Grant for Sc. Sch. NSh-5655.2008.2
文摘We present a study of the inclusive photon spectra from 5.9 million J/ψ decays collected with the KEDR detector at the VEPP-4M e＋e collider. We measure the branching fraction of radiative decay J/ψ→ηcγ, ηc width and mass. Our preliminary results are： M（ηc） = 2979.4± 1.5 ± 1.9 MeV/c^2, Г（ηc） = 27.8±5.1 ±3.3 MeV, B（Jψ→ηcγ） = （2.34±0.15±0.40）%.
基金Supported by Deutsche Forschungsgemeinschaft Contract No.FA67/31-2 and No.GRK683also part of the European Community-Research Infrastructure Integrating Activity 'Study of Strongly Interacting Matter' (acronym Hadron- Physics2,Grant Agreement No.227431)+1 种基金Russian President grant 'Scientific Schools' No.3400.2010.2Russian Science and Innovations Federal Agency contract No.02.740.11.0238
文摘We discuss a possible interpretation of the open charm mesons D＊s0 （2317）,D s1 （2460） and the hidden charm mesons X（3872）,Y（3940） and Y（4140） as hadron molecules.Using a phenomenological Lagrangian approach we review the strong and radiative decays of the D＊ s0 （2317） and D s1 （2460） states.The X（3872） is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration.Determing the radiative （γJ/ψ and γψ（2s）） and strong （J/ψ2π and J/ψ3π） decay modes we show that the present experimental observation is consistent with the molecular structure assumption of the X（3872）.Finally,we give evidence for molecular interpretations of the Y（3940） and Y（4140） related to the observed strong decay modes J/ψ＋ω or J/ψ＋φ,respectively.
基金We would like to thank Prof.Zhen Hu for fruitful discussions.This work was supported by the National Natural Science Foundation of China under Grant Nos.11575017,11761141009,11975076,and 11661141008the National Key R&D Program of China under the contract No.2018YFA0403902the CAS Center for Excellence in Particle Physics(CCEPP).
文摘The three lowest-lying r states,ie,r(1S),T(2S),and r(35),composed of b pairs and below the BB threshold,provide a good platform for the researches of hadronic physics and physics beyond the Standard Model.They can be produced directly in ete--colliding experiments,such as CLEO,Babar,and Belle,with low continuum backgrounds.In these experiments,many measurements of the exclusive r(1S)and r(2S)decays into light hadrons,which shed light on the"80%rule"for the Okubo-Zweig-lizuka suppressed decays in the bottomonium sector,were carried out.Meanwhile,many studies of the charmonium and bottomonium productions in r(1S,2S,3S)decays were performed,to distinguish different Quantum Chromodynamics(QCD)models.Besides,exotic states and new physics were also extensively explored in r(1S,2S,3S)decays at CLEO,BaBar,and Bell.The r(1S,2S,3S)states can also be produced in p collisions and in ollisions involving heavy ions.The precision measurements of their cross sections and polarizations at the large hadron collider(LHC),especially in the CMS,ATLAS,and LHCb experiments,help to understand r production mechanisms in Pp collisions.The observation of the sequential r suppession in heavy ion collisions at CMS,LHCb,and ALICE is of great importance for verifying the quark-gluon plasma predicted by QCD.In this article,we review the experimental results on T(1S,2S,3S)at e+e-colliders and the LHC,and summarize their prospects at Belle II and the LHC.
