In the paper, we apply the kT factorization approach to deal with the B8 → fofo（980） transition form factors in the large recoil regions, i.e. the small q2 regions. For the purpose, we adopt the B-meson wave-functi...In the paper, we apply the kT factorization approach to deal with the B8 → fofo（980） transition form factors in the large recoil regions, i.e. the small q2 regions. For the purpose, we adopt the B-meson wave-functions ЖB, ЖB and that include the three-Fock states contributions to do our discussion. Although the scalar meson fo（980） is widely perceived as the 4-quark bound state （scenario 2）, but the distribution amplitudes of 4-quark states are still unknown to us, so we adopt 2-quark model （scenario 1） for scalar meson fo（980） in our discussion. By varying the B-meson wave-function parameters within their reasonable regions, we obtain Fo（0） = F＋（0） = 0.20 ± 0.02, FT（O） = 0.24 4± 0.02. Our present results for these form factors are consistent with the light-cone sum rule results obtained in the literature.展开更多
By employing the perturbative QCD（PQCD） factorization approach, we study the quasi-two-body B（s）^0→ηc（2S）π^＋π^- decays, where the pion pair comes from the S-wave resonance f0（X）. The Breit-Wigner formula ...By employing the perturbative QCD（PQCD） factorization approach, we study the quasi-two-body B（s）^0→ηc（2S）π^＋π^- decays, where the pion pair comes from the S-wave resonance f0（X）. The Breit-Wigner formula for the f0（500） and f0（1500） resonances and the Flatt′e model for the f0（980） resonance are adopted to parameterize the time-like scalar form factors in the two-pion distribution amplitudes. As a comparison, Bugg＇s model is also used for the wide f0（500） in this work. For decay rates, we found the following PQCD predictions：（a）-B（Bs^0 →ηc（2S）f0（X）[π^＋π^-]s）= 2.67-1.08^＋1.78 ×10^-5 when the contributions from f0（980） and f0（1500） are all taken into account;（b）B（B0→η-c（2S）f0（500）[π^＋π^-]s） = 1.40（-0.56）（＋0.92） ×10^-6 in the Breit-Wigner model and 1.53（-0.61）^（＋0.97） ×10^-6 in Bugg＇s model.展开更多
In this paper,we calculated the branching ratios and direct CP violation of the four B→Kπ decays with the inclusion of all currently known next-to-leading order（NLO） contributions by employing the perturbative QCD...In this paper,we calculated the branching ratios and direct CP violation of the four B→Kπ decays with the inclusion of all currently known next-to-leading order（NLO） contributions by employing the perturbative QCD（pQCD） factorization approach.We found that（a） Besides the 10%enhancement from the NLO vertex corrections,the quark-loops and magnetic penguins,the NLO contributions to the form factors can provide an additional^15%enhancement to the branching ratios,and lead to a very good agreement with the data;（b） The NLO pQCD predictions are A_（CP）^（dir）（B^0→K~＋π~0）=（-6.5±3.1）%and A_（CP）^（dir）（B~＋→K~＋π~0）=（2.2±2.0）%,become well consistent with the data due to the inclusion of the NLO contributions.展开更多
By employing the perturbative QCD （pQCD） factorization approach, we calculate some important next- to-leading-order （NLO） contributions to the two-body charmless hadronic decays B^＋ →ρ^＋η（＇） and B^0 → ρ^...By employing the perturbative QCD （pQCD） factorization approach, we calculate some important next- to-leading-order （NLO） contributions to the two-body charmless hadronic decays B^＋ →ρ^＋η（＇） and B^0 → ρ^0（ω, φ）η（＇）, induced by the vertex QCD corrections, the quark-loops as well as the chromo-magnetic penguins. From the numerical results and phenomenological analysis we find that （a） for B^± → ρ^±η（＇） （B^0 → ρ^0（ω, φ）η（＇）decays, the partial NLO contributions to branching ratios are small （large） in magnitude; and （b） the pQCD predictions for ACP^dir（B^± → ρ^±η（＇）） are consistent with the data, while the predicted .ACP（B^0 → ρ^0（ω）η（＇）） are generally large in magnitude and could be tested by the forthcoming LHCb experiments.展开更多
In foreign language teaching, there appear a lot of approaches. This essay lays special stress on humanistic approach and analyses the influence of some important affective factors on language learning, for the purpos...In foreign language teaching, there appear a lot of approaches. This essay lays special stress on humanistic approach and analyses the influence of some important affective factors on language learning, for the purpose of inviting teachers＇ attention to students＇ emotions in fulfilling their teaching task.展开更多
The state space representation of the Bezout identity for generalized systems proposed by (Wang and Balas, 1989) is discussed again. A more concise way of description and proof is presented and the physical signific...The state space representation of the Bezout identity for generalized systems proposed by (Wang and Balas, 1989) is discussed again. A more concise way of description and proof is presented and the physical significance of the result in is also analyzed. Thus, our work is of independent interest.展开更多
We study the CP-averaged branching fractions and the CP-violating asymmetries in the pure annihilation decays of B^(s)_(0)→a^(+)_(0)a^(−)_(0)and B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0),where a_(0)[K^(∗)_(0)]denotes the scala...We study the CP-averaged branching fractions and the CP-violating asymmetries in the pure annihilation decays of B^(s)_(0)→a^(+)_(0)a^(−)_(0)and B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0),where a_(0)[K^(∗)_(0)]denotes the scalar a_(0)(980)and a_(0)(1450)[K^(∗)_(0)(800)(orκ)and K^(∗)_(0)(1430)],with the perturbative QCD factorization approach under the assumption of two-quark structure for the a_(0)and K^(∗)_(0)states.The numerical results show that the branching ratios of the B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0)decays are in the order of 10^(−6),while the decay rates of the B^(s)_(0)→a^(+)_(0)a^(−)_(0)modes are in the order of 10−5.In light of the measured modes with the same quark components in the pseudoscalar sector,namely,B^(0)_(d)→K^(+)k_(-)and B^(0)_(s)→π^(+)π_(−),the predictions for the considered decay modes in this work are expected to be measured at the Large Hadron Collider beauty and/or Belle-Ⅱexperiments in the(near)future.Meanwhile,it is of great interest to find that the twist-3 distribution amplitudesφ^(S)andφ^(T)with inclusion of the Gegenbauer polynomials for the scalar a_(0)(1450)and K^(∗)_(0)(1430)states in scenario 2 contribute slightly to the branching ratios while significantly to the CP violations in the B^(0)_(d)→K^(∗)_(0)(1430)+K^(∗)_(0)(1430)−and B^(0)_(s)→a_(0)(1450)+a_(0)(1450)−decays,which indicates that,compared to the asymptoticφ^(S)andφ^(T),these Gegenbauer polynomials could change the strong phases evidently in these pure annihilation decay channels.These predictions await for the future confirmation experimentally,which could further provide useful information to help explore the inner structure of the scalars and shed light on the annihilation decay mechanism.展开更多
In this paper,we calculate the branching ratios for B^+→D_s^+η,B^+→D_s^+η′,B^+→D_s^(*+)η and B^+→D_s^(*+)η′decays by employing the perturbative QCD (pQCD) factorization approach.Under the two kinds of η-η...In this paper,we calculate the branching ratios for B^+→D_s^+η,B^+→D_s^+η′,B^+→D_s^(*+)η and B^+→D_s^(*+)η′decays by employing the perturbative QCD (pQCD) factorization approach.Under the two kinds of η-η′ mixingschemes,the quark-flavor mixing scheme and the singlet-octet mixing scheme,we find that the calculated branchingratios agree well with the currently available experimental upper limits.We also consider the so called 'f_D_s puzzle',byusing two groups of parameters about the D_s^((*)) meson decay constants,that are f_D_s = 241 MeV,f_D_s~* = 272 MeV andf_D_s = 274 MeV,f_D_s~* = 312 MeV,to calculate the branching ratios for the considered decays.We find that the resultschange 30% by using these two different kinds of paramters.展开更多
Pancreatic metastases are rare,with a reported incidence varying from 1.6%to 11%in autopsy studies of patients with advanced malignancy.In clinical series,the frequency of pancreatic metastases ranges from 2%to 5%of a...Pancreatic metastases are rare,with a reported incidence varying from 1.6%to 11%in autopsy studies of patients with advanced malignancy.In clinical series,the frequency of pancreatic metastases ranges from 2%to 5%of all pancreatic malignant tumors.However,the pancreas is an elective site for metastases from carcinoma of the kidney and this peculiarity has been reported by several studies.The epidemiology,clinical presentation,and treatment of pancreatic metastases from renal cell carcinoma are known from singleinstitution case reports and literature reviews.Thereis currently very limited experience with the surgical resection of isolated pancreatic metastasis,and the role of surgery in the management of these patients has not been clearly defined.In fact,for many years pancreatic resections were associated with high rates of morbidity and mortality,and metastatic disease to the pancreas was considered to be a terminal-stage condition.More recently,a significant reduction in the operative risk following major pancreatic surgery has been demonstrated,thus extending the indication for these operations to patients with metastatic disease.展开更多
An analytical approach was presented for estimating the factor of safety(FS) for slope failure, with consideration of the impact of a confined aquifer. An upward-moving wetting front from the confined water was assume...An analytical approach was presented for estimating the factor of safety(FS) for slope failure, with consideration of the impact of a confined aquifer. An upward-moving wetting front from the confined water was assumed and the pore water pressure distribution was then estimated and used to obtain the analytical expression of FS. Then, the validation of the theoretical analysis was applied based on an actual case in Hong Kong. It is shown that the presence of a confined aquifer leads to a lower FS value, and the impact rate of hydrostatic pressure on FS increases as the confined water pressure increases, approaching to a maximum value determined by the ratio of water density to saturated soil density. It is also presented that the contribution of hydrostatic pressure and hydrodynamic pressure to the slope stability vary with the confined aquifer pressure.展开更多
Based on the assumption of a two-quark structure of the scalar meson f0（980） ,we calculate the branching ratios and CP-violating asymmetries for the four B → f0（980） π and B → f0（980） η^（＇） decays by empl...Based on the assumption of a two-quark structure of the scalar meson f0（980） ,we calculate the branching ratios and CP-violating asymmetries for the four B → f0（980） π and B → f0（980） η^（＇） decays by employing the perturbative QCD（pQCD） factorization approach. The leading order pQCD predictions for branching ratios are,Br（B^-→ f0（980） π^-） ～ 2.5×10^-6,Br（Bˉ^0 → f0（980） π^0） ～ 2.6×10^-7,Br（Bˉ^0 → f0（980） η） ～ 2.5×10^-7 and Br（Bˉ^0 → f0（980） η ） ～ 6.7×10^-7,which are consistent with both the QCD factorization predictions and the experimental upper limits.展开更多
By employing the perturbative QCD （pQCD） factorization approach, we calculate the full leading and the partial next-to-leading order （NLO） contributions to the seven B →πη（′） and η（′）η（′） decays. For...By employing the perturbative QCD （pQCD） factorization approach, we calculate the full leading and the partial next-to-leading order （NLO） contributions to the seven B →πη（′） and η（′）η（′） decays. For B^＋→ π＋η（′） decays, the pQCD predictions for their decay rates agree very well with the data after the inclusion of the small NLO contributions. For neutral decays, the pQCD predictions are also consistent with the experimental upper limits and can be tested by the LHC experiments. The measured value of dir .Acp^dir（π＋η）= 19±7% can also be accommodated by the pQCD approach.展开更多
We study the quasi-two-body decays B(s)ψ[K*(892)K*(1410)K*(1680)]ψKπby employing the perturbative QCD(PQCD)factorization approach,where the charmoniaψrepresents J/ψandψ(2S).The corresponding decay channels are s...We study the quasi-two-body decays B(s)ψ[K*(892)K*(1410)K*(1680)]ψKπby employing the perturbative QCD(PQCD)factorization approach,where the charmoniaψrepresents J/ψandψ(2S).The corresponding decay channels are studied by constructing the kaon-pion distribution amplitude(DA)ΦKπP,which comprises important final state interactions between the kaon and pion in the resonant region.Relativistic Breit-Wigner formulas are adopted to parameterize the time-like form factor FKπappearing in the kaon-pion DAs.The SU(3)flavor symmetry breaking effect resulting from the mass difference between the kaon and pion is taken into account,which makes significant contributions to the longitudinal polarizations.The observed branching ratios and the polarization fractions of B(s)ψK*(892)ψKπare accommodated by tuning hadronic parameters for the kaon-pion DAs.The PQCD predictions for B(s)ψ[K*(1410)K*(1680)]ψKπmodes from the same set of parameters can be tested by precise data obtained in the future from LHCb and BelleⅡexperiments.展开更多
A new construction approach of the Bezout identity for singular systems with directcontrol feedthrough is developed here on the basis of a normal dynamic compensator design, and theparameterization of all Properly sta...A new construction approach of the Bezout identity for singular systems with directcontrol feedthrough is developed here on the basis of a normal dynamic compensator design, and theparameterization of all Properly stabilizing normal controllers is characterized and interpreted in astate-space form. Finally, an illustrative example is given.展开更多
In this paper, we calculate the branching ratios and the direct CP-violating asymmetries for decays B^0 → a0^0（980）π^0, a0^＋ （980）π^-, a0^-（980）π^＋ and B^- → a0^0 （980）π^-, a0^- （980）π^0 by employin...In this paper, we calculate the branching ratios and the direct CP-violating asymmetries for decays B^0 → a0^0（980）π^0, a0^＋ （980）π^-, a0^-（980）π^＋ and B^- → a0^0 （980）π^-, a0^- （980）π^0 by employing the perturbative QCD （pQCD） factorization approach at the leading order. We found that （a） the pQCD predictions for the branching ratios are around （0.4-2.8） × 10^-6, consistent with currently available experimental upper limits; （b） the CP asymmetries of B^0→ a0^0（980）π^0 and B^- → a0^- （980）π^0 decays can be large, about （70-80）% for α= 100°.展开更多
Motivated by the recent LHCb collaboration measurements of charmless three-body decays of Bs-0 meson, we calculate the branching fractions of Bs→K0h＋h＇-（h（＇）=K,π）decay modes using the factorization approach.B...Motivated by the recent LHCb collaboration measurements of charmless three-body decays of Bs-0 meson, we calculate the branching fractions of Bs→K0h＋h＇-（h（＇）=K,π）decay modes using the factorization approach.Both the resonant and nonresonant contributions are studied in detail. For the decays Bs→K0h＋h＇-（h（＇）=K,π） and Bs→K0h＋h＇-（h（＇）=K,π）our resultsagree well with experimental data, and the former is dominated by the K＊, while the latter one is dominated by the nonresonant con-tribution. Considering the flavor S U（3） symmetry violation, the sum of branching fractions of Bs→K0h＋h＇-（h（＇）=K,π）could accommodate the data well too. It should be noted that both branching fractions are sensitive to the scalar density （Kπ｜sq｜0））. Furthermore, the resonant contributions are dominated by the scalar K;（1430）. We hope that these branching fractions could be measured individually in the experiments so as to test the factorization approach and the flavor S U（3） asymmetry. Moreover, the direct CP asymmetries of these decays are also investigated, which could be measured in the running LHCb experiment and Super-b factory in the future.展开更多
In this study,the heavy to heavy decay of D^(0)_(s)→D^(*+)D^(-)is evaluated through the factorization approach by using the final state interaction as an effective correction.Under the factorization approach,this dec...In this study,the heavy to heavy decay of D^(0)_(s)→D^(*+)D^(-)is evaluated through the factorization approach by using the final state interaction as an effective correction.Under the factorization approach,this decay mode occurs only through the annihilation process,so a small amount is produced.Feynman's rules state that six meson pairs can be assumed for the intermediate states before the final meson pairs are produced.By taking into account the effects of twelve final state interaction diagrams in the calculations,a significant correction is obtained.These effects correct the value of the branching ratio obtained by the pure factorization approach from(2.41±1.37)×10^(-5)to(8.27土2.23)×10^(-5).The value obtained for the branching ratio of the D^(0)_(s)→D^(*+)D^(-)decay is consistent with the experimental results.展开更多
Within the framework of perturbative QCD factorization,we investigate the nonfactorizable contributions to the factorization-forbidden quasi-two-body decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=π,K...Within the framework of perturbative QCD factorization,we investigate the nonfactorizable contributions to the factorization-forbidden quasi-two-body decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=π,K.We compare our predicted branching ratios for the B_(()(s))→K_(χc0)→Kπ^(+)π-(K^(+)K^(-))decay with available experiment data as well as predictions by other theoretical studies.The branching ratios of these decays are consistent with data and other theoretical predictions.However,in the Cabibbo-suppressed decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=K^(0),π,the values of the branching ratios are of the order of 10^(-7)and 10^(-8).The ratio R_((χ)_(c0))between the decays B^(+)→π^(+)χ_(c0)→π^(+)π^(+)π^(-)and B^(+)→K^(+)χc0→K^(+)π^(+)π^(-)and the distribution of branching ratios for different decay modes in invariant mass are considered in this study.展开更多
The contributions for the kaon pair from the intermediate statesρ(1450)^(+) andρ(1700)^(+) in the decays B+→D¯^(0)K+K¯^(0),B^(0)→D−K+K¯^(0),and B^(0)_(s)→D−_(s)K+K¯^(0)are analyzed within the ...The contributions for the kaon pair from the intermediate statesρ(1450)^(+) andρ(1700)^(+) in the decays B+→D¯^(0)K+K¯^(0),B^(0)→D−K+K¯^(0),and B^(0)_(s)→D−_(s)K+K¯^(0)are analyzed within the perturbative QCD factorization approach.The decay amplitudes for all concerned decays in this work are dominated by the factorizable Feynman diagrams with the emission of the kaon pair,and the chargedρmesons should be of great importance in the KK channel of the related three-body B decays.Moreover,these quasi-two-body decays are CKM-favored,and the relevant branching ratios are predicted to be in the order of 10^(−5),which have the potential to be measured by experiments.It is also shown that the contributions of the subprocessesρ(1450,1700)^(+)→KK for the three-body B meson decays are considerable according to the total three-body branching fractions presented by Belle.Therefore,the decays B+→D¯^(0)K+K¯^(0),B^(0)→D−K+K¯^(0),and B^(0)_(s)→D−_(s)K^(+)K¯^(0)can be employed to study the properties ofρ(1450)andρ(1700)in the LHCb and Belle-II experiments.展开更多
基金Supported by the Fundamental Research Funds for the Central Universities under Grant No.CDJZR10100023
文摘In the paper, we apply the kT factorization approach to deal with the B8 → fofo（980） transition form factors in the large recoil regions, i.e. the small q2 regions. For the purpose, we adopt the B-meson wave-functions ЖB, ЖB and that include the three-Fock states contributions to do our discussion. Although the scalar meson fo（980） is widely perceived as the 4-quark bound state （scenario 2）, but the distribution amplitudes of 4-quark states are still unknown to us, so we adopt 2-quark model （scenario 1） for scalar meson fo（980） in our discussion. By varying the B-meson wave-function parameters within their reasonable regions, we obtain Fo（0） = F＋（0） = 0.20 ± 0.02, FT（O） = 0.24 4± 0.02. Our present results for these form factors are consistent with the light-cone sum rule results obtained in the literature.
基金Supported by National Natural Science Foundation of China(11235005,11547038)
文摘By employing the perturbative QCD（PQCD） factorization approach, we study the quasi-two-body B（s）^0→ηc（2S）π^＋π^- decays, where the pion pair comes from the S-wave resonance f0（X）. The Breit-Wigner formula for the f0（500） and f0（1500） resonances and the Flatt′e model for the f0（980） resonance are adopted to parameterize the time-like scalar form factors in the two-pion distribution amplitudes. As a comparison, Bugg＇s model is also used for the wide f0（500） in this work. For decay rates, we found the following PQCD predictions：（a）-B（Bs^0 →ηc（2S）f0（X）[π^＋π^-]s）= 2.67-1.08^＋1.78 ×10^-5 when the contributions from f0（980） and f0（1500） are all taken into account;（b）B（B0→η-c（2S）f0（500）[π^＋π^-]s） = 1.40（-0.56）（＋0.92） ×10^-6 in the Breit-Wigner model and 1.53（-0.61）^（＋0.97） ×10^-6 in Bugg＇s model.
基金Supported by National Natural Science Foundation of China(10975074,11235005)
文摘In this paper,we calculated the branching ratios and direct CP violation of the four B→Kπ decays with the inclusion of all currently known next-to-leading order（NLO） contributions by employing the perturbative QCD（pQCD） factorization approach.We found that（a） Besides the 10%enhancement from the NLO vertex corrections,the quark-loops and magnetic penguins,the NLO contributions to the form factors can provide an additional^15%enhancement to the branching ratios,and lead to a very good agreement with the data;（b） The NLO pQCD predictions are A_（CP）^（dir）（B^0→K~＋π~0）=（-6.5±3.1）%and A_（CP）^（dir）（B~＋→K~＋π~0）=（2.2±2.0）%,become well consistent with the data due to the inclusion of the NLO contributions.
基金Supported by the National Natural Science Foundation of China under Grant No.10575052,10605012,and 10735080
文摘By employing the perturbative QCD （pQCD） factorization approach, we calculate some important next- to-leading-order （NLO） contributions to the two-body charmless hadronic decays B^＋ →ρ^＋η（＇） and B^0 → ρ^0（ω, φ）η（＇）, induced by the vertex QCD corrections, the quark-loops as well as the chromo-magnetic penguins. From the numerical results and phenomenological analysis we find that （a） for B^± → ρ^±η（＇） （B^0 → ρ^0（ω, φ）η（＇）decays, the partial NLO contributions to branching ratios are small （large） in magnitude; and （b） the pQCD predictions for ACP^dir（B^± → ρ^±η（＇）） are consistent with the data, while the predicted .ACP（B^0 → ρ^0（ω）η（＇）） are generally large in magnitude and could be tested by the forthcoming LHCb experiments.
文摘In foreign language teaching, there appear a lot of approaches. This essay lays special stress on humanistic approach and analyses the influence of some important affective factors on language learning, for the purpose of inviting teachers＇ attention to students＇ emotions in fulfilling their teaching task.
文摘The state space representation of the Bezout identity for generalized systems proposed by (Wang and Balas, 1989) is discussed again. A more concise way of description and proof is presented and the physical significance of the result in is also analyzed. Thus, our work is of independent interest.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.11765012 and 11205072by the Research Fund of Jiangsu Normal University(No.HB2016004)supported by the Undergraduate Research&Practice Innovation Program of Jiangsu Province(No.201810320103Z)。
文摘We study the CP-averaged branching fractions and the CP-violating asymmetries in the pure annihilation decays of B^(s)_(0)→a^(+)_(0)a^(−)_(0)and B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0),where a_(0)[K^(∗)_(0)]denotes the scalar a_(0)(980)and a_(0)(1450)[K^(∗)_(0)(800)(orκ)and K^(∗)_(0)(1430)],with the perturbative QCD factorization approach under the assumption of two-quark structure for the a_(0)and K^(∗)_(0)states.The numerical results show that the branching ratios of the B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0)decays are in the order of 10^(−6),while the decay rates of the B^(s)_(0)→a^(+)_(0)a^(−)_(0)modes are in the order of 10−5.In light of the measured modes with the same quark components in the pseudoscalar sector,namely,B^(0)_(d)→K^(+)k_(-)and B^(0)_(s)→π^(+)π_(−),the predictions for the considered decay modes in this work are expected to be measured at the Large Hadron Collider beauty and/or Belle-Ⅱexperiments in the(near)future.Meanwhile,it is of great interest to find that the twist-3 distribution amplitudesφ^(S)andφ^(T)with inclusion of the Gegenbauer polynomials for the scalar a_(0)(1450)and K^(∗)_(0)(1430)states in scenario 2 contribute slightly to the branching ratios while significantly to the CP violations in the B^(0)_(d)→K^(∗)_(0)(1430)+K^(∗)_(0)(1430)−and B^(0)_(s)→a_(0)(1450)+a_(0)(1450)−decays,which indicates that,compared to the asymptoticφ^(S)andφ^(T),these Gegenbauer polynomials could change the strong phases evidently in these pure annihilation decay channels.These predictions await for the future confirmation experimentally,which could further provide useful information to help explore the inner structure of the scalars and shed light on the annihilation decay mechanism.
文摘In this paper,we calculate the branching ratios for B^+→D_s^+η,B^+→D_s^+η′,B^+→D_s^(*+)η and B^+→D_s^(*+)η′decays by employing the perturbative QCD (pQCD) factorization approach.Under the two kinds of η-η′ mixingschemes,the quark-flavor mixing scheme and the singlet-octet mixing scheme,we find that the calculated branchingratios agree well with the currently available experimental upper limits.We also consider the so called 'f_D_s puzzle',byusing two groups of parameters about the D_s^((*)) meson decay constants,that are f_D_s = 241 MeV,f_D_s~* = 272 MeV andf_D_s = 274 MeV,f_D_s~* = 312 MeV,to calculate the branching ratios for the considered decays.We find that the resultschange 30% by using these two different kinds of paramters.
文摘Pancreatic metastases are rare,with a reported incidence varying from 1.6%to 11%in autopsy studies of patients with advanced malignancy.In clinical series,the frequency of pancreatic metastases ranges from 2%to 5%of all pancreatic malignant tumors.However,the pancreas is an elective site for metastases from carcinoma of the kidney and this peculiarity has been reported by several studies.The epidemiology,clinical presentation,and treatment of pancreatic metastases from renal cell carcinoma are known from singleinstitution case reports and literature reviews.Thereis currently very limited experience with the surgical resection of isolated pancreatic metastasis,and the role of surgery in the management of these patients has not been clearly defined.In fact,for many years pancreatic resections were associated with high rates of morbidity and mortality,and metastatic disease to the pancreas was considered to be a terminal-stage condition.More recently,a significant reduction in the operative risk following major pancreatic surgery has been demonstrated,thus extending the indication for these operations to patients with metastatic disease.
基金Project(R5110012)supported by Special Foundation for Distinguished Young Scholars of Zhejiang Province,ChinaProject(2009C33117)supported by The General Program of Natural Science Foundation of Zhejiang Province,China
文摘An analytical approach was presented for estimating the factor of safety(FS) for slope failure, with consideration of the impact of a confined aquifer. An upward-moving wetting front from the confined water was assumed and the pore water pressure distribution was then estimated and used to obtain the analytical expression of FS. Then, the validation of the theoretical analysis was applied based on an actual case in Hong Kong. It is shown that the presence of a confined aquifer leads to a lower FS value, and the impact rate of hydrostatic pressure on FS increases as the confined water pressure increases, approaching to a maximum value determined by the ratio of water density to saturated soil density. It is also presented that the contribution of hydrostatic pressure and hydrodynamic pressure to the slope stability vary with the confined aquifer pressure.
文摘Based on the assumption of a two-quark structure of the scalar meson f0（980） ,we calculate the branching ratios and CP-violating asymmetries for the four B → f0（980） π and B → f0（980） η^（＇） decays by employing the perturbative QCD（pQCD） factorization approach. The leading order pQCD predictions for branching ratios are,Br（B^-→ f0（980） π^-） ～ 2.5×10^-6,Br（Bˉ^0 → f0（980） π^0） ～ 2.6×10^-7,Br（Bˉ^0 → f0（980） η） ～ 2.5×10^-7 and Br（Bˉ^0 → f0（980） η ） ～ 6.7×10^-7,which are consistent with both the QCD factorization predictions and the experimental upper limits.
基金Supported by National Natural Science Foundation of China (10575052, 10735080)Specialized Research Fund for Doctoral Program of Higher Education (SRFDP) (20050319008)
文摘By employing the perturbative QCD （pQCD） factorization approach, we calculate the full leading and the partial next-to-leading order （NLO） contributions to the seven B →πη（′） and η（′）η（′） decays. For B^＋→ π＋η（′） decays, the pQCD predictions for their decay rates agree very well with the data after the inclusion of the small NLO contributions. For neutral decays, the pQCD predictions are also consistent with the experimental upper limits and can be tested by the LHC experiments. The measured value of dir .Acp^dir（π＋η）= 19±7% can also be accommodated by the pQCD approach.
基金Supported by the National Natural Science Foundation of China(11947013,11605060,11775117,11547020)Supported by the Natural Science Foundation of Jiangsu Province(BK20190508)+1 种基金the Research Start-up Funding of Nanjing Agricultural UniversitySupported in part by the Natural Science Foundation of Hebei Province(A2019209449)。
文摘We study the quasi-two-body decays B(s)ψ[K*(892)K*(1410)K*(1680)]ψKπby employing the perturbative QCD(PQCD)factorization approach,where the charmoniaψrepresents J/ψandψ(2S).The corresponding decay channels are studied by constructing the kaon-pion distribution amplitude(DA)ΦKπP,which comprises important final state interactions between the kaon and pion in the resonant region.Relativistic Breit-Wigner formulas are adopted to parameterize the time-like form factor FKπappearing in the kaon-pion DAs.The SU(3)flavor symmetry breaking effect resulting from the mass difference between the kaon and pion is taken into account,which makes significant contributions to the longitudinal polarizations.The observed branching ratios and the polarization fractions of B(s)ψK*(892)ψKπare accommodated by tuning hadronic parameters for the kaon-pion DAs.The PQCD predictions for B(s)ψ[K*(1410)K*(1680)]ψKπmodes from the same set of parameters can be tested by precise data obtained in the future from LHCb and BelleⅡexperiments.
文摘A new construction approach of the Bezout identity for singular systems with directcontrol feedthrough is developed here on the basis of a normal dynamic compensator design, and theparameterization of all Properly stabilizing normal controllers is characterized and interpreted in astate-space form. Finally, an illustrative example is given.
基金Supported by National Natural Science Foundation of China (10575052,10735080)
文摘In this paper, we calculate the branching ratios and the direct CP-violating asymmetries for decays B^0 → a0^0（980）π^0, a0^＋ （980）π^-, a0^-（980）π^＋ and B^- → a0^0 （980）π^-, a0^- （980）π^0 by employing the perturbative QCD （pQCD） factorization approach at the leading order. We found that （a） the pQCD predictions for the branching ratios are around （0.4-2.8） × 10^-6, consistent with currently available experimental upper limits; （b） the CP asymmetries of B^0→ a0^0（980）π^0 and B^- → a0^- （980）π^0 decays can be large, about （70-80）% for α= 100°.
基金supported by the National Natural Science Foundation of China(Grants Nos.11175151 and 11235005)the Program for New Century Excellent Talents in University(NCET)by Ministry of Education of China(Grant No.NCET-13-0991)
文摘Motivated by the recent LHCb collaboration measurements of charmless three-body decays of Bs-0 meson, we calculate the branching fractions of Bs→K0h＋h＇-（h（＇）=K,π）decay modes using the factorization approach.Both the resonant and nonresonant contributions are studied in detail. For the decays Bs→K0h＋h＇-（h（＇）=K,π） and Bs→K0h＋h＇-（h（＇）=K,π）our resultsagree well with experimental data, and the former is dominated by the K＊, while the latter one is dominated by the nonresonant con-tribution. Considering the flavor S U（3） symmetry violation, the sum of branching fractions of Bs→K0h＋h＇-（h（＇）=K,π）could accommodate the data well too. It should be noted that both branching fractions are sensitive to the scalar density （Kπ｜sq｜0））. Furthermore, the resonant contributions are dominated by the scalar K;（1430）. We hope that these branching fractions could be measured individually in the experiments so as to test the factorization approach and the flavor S U（3） asymmetry. Moreover, the direct CP asymmetries of these decays are also investigated, which could be measured in the running LHCb experiment and Super-b factory in the future.
文摘In this study,the heavy to heavy decay of D^(0)_(s)→D^(*+)D^(-)is evaluated through the factorization approach by using the final state interaction as an effective correction.Under the factorization approach,this decay mode occurs only through the annihilation process,so a small amount is produced.Feynman's rules state that six meson pairs can be assumed for the intermediate states before the final meson pairs are produced.By taking into account the effects of twelve final state interaction diagrams in the calculations,a significant correction is obtained.These effects correct the value of the branching ratio obtained by the pure factorization approach from(2.41±1.37)×10^(-5)to(8.27土2.23)×10^(-5).The value obtained for the branching ratio of the D^(0)_(s)→D^(*+)D^(-)decay is consistent with the experimental results.
基金Supported by the National Natural Science Foundation of China(11235005,11847141,12105112)the Natural Science Foundation of Jiangsu Education Committee(21KJB140027)the Natural Science Foundation of Huaiyin Institute of Technology(21HGZ012)。
文摘Within the framework of perturbative QCD factorization,we investigate the nonfactorizable contributions to the factorization-forbidden quasi-two-body decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=π,K.We compare our predicted branching ratios for the B_(()(s))→K_(χc0)→Kπ^(+)π-(K^(+)K^(-))decay with available experiment data as well as predictions by other theoretical studies.The branching ratios of these decays are consistent with data and other theoretical predictions.However,in the Cabibbo-suppressed decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=K^(0),π,the values of the branching ratios are of the order of 10^(-7)and 10^(-8).The ratio R_((χ)_(c0))between the decays B^(+)→π^(+)χ_(c0)→π^(+)π^(+)π^(-)and B^(+)→K^(+)χc0→K^(+)π^(+)π^(-)and the distribution of branching ratios for different decay modes in invariant mass are considered in this study.
基金Supported by the National Natural Science Foundation of China(11947011)the Natural Science Foundation of Jiangsu Province(BK20191010)the Scientific Research Foundation of Nanjing Institute of Technology(YKJ201854)。
文摘The contributions for the kaon pair from the intermediate statesρ(1450)^(+) andρ(1700)^(+) in the decays B+→D¯^(0)K+K¯^(0),B^(0)→D−K+K¯^(0),and B^(0)_(s)→D−_(s)K+K¯^(0)are analyzed within the perturbative QCD factorization approach.The decay amplitudes for all concerned decays in this work are dominated by the factorizable Feynman diagrams with the emission of the kaon pair,and the chargedρmesons should be of great importance in the KK channel of the related three-body B decays.Moreover,these quasi-two-body decays are CKM-favored,and the relevant branching ratios are predicted to be in the order of 10^(−5),which have the potential to be measured by experiments.It is also shown that the contributions of the subprocessesρ(1450,1700)^(+)→KK for the three-body B meson decays are considerable according to the total three-body branching fractions presented by Belle.Therefore,the decays B+→D¯^(0)K+K¯^(0),B^(0)→D−K+K¯^(0),and B^(0)_(s)→D−_(s)K^(+)K¯^(0)can be employed to study the properties ofρ(1450)andρ(1700)in the LHCb and Belle-II experiments.
