We calculate the D s 1 （2536） ^＋ decays into D＊K channels,including the decay D s 1 （2536） ＋ → D ＋ π-K ＋ through a virtual D＊0 in a constituent quark model.Widths and S/D amplitudes ratio are in agreement ...We calculate the D s 1 （2536） ^＋ decays into D＊K channels,including the decay D s 1 （2536） ＋ → D ＋ π-K ＋ through a virtual D＊0 in a constituent quark model.Widths and S/D amplitudes ratio are in agreement with the recent Belle and BABAR data,being the results sensitive to 1 P 1 and 3 P 1 mixture.展开更多
We present a preliminary measurement of the B（Ds→μvu） with the Belle experiment at the KEKB collider. We select Ds →μvu decays with a method that provides a high-purity of the selected sample and an absolute mea...We present a preliminary measurement of the B（Ds→μvu） with the Belle experiment at the KEKB collider. We select Ds →μvu decays with a method that provides a high-purity of the selected sample and an absolute measurement of the branching fraction. The results are based on a data sample of 550 fb^-1 and are compared to similar measurements by other experiments as well as to the predictions of LQCD. We conclude with short prospects for improvements in the accuracy of the measurement.展开更多
It was found that the vector meson pair from the pseudoscalar decays can form an entangled state.In this work we give out detailed explanations on the polarization correlation of the two entangled vector mesons.It is ...It was found that the vector meson pair from the pseudoscalar decays can form an entangled state.In this work we give out detailed explanations on the polarization correlation of the two entangled vector mesons.It is demonstrated that an experimental test of the Clauser-Horne inequality can be carried out through measuring the azimuthal distribution of four pseudoscalars in the cascade decay ηc→ VV →(PP)(PP),and the measurement of this process is feasible with the current running experiments in tau-charm factory.Moreover,a brief discussion on the polarization correlation of the two vector mesons from B → VV decays is also presented.展开更多
By employing the perturbative QCD （pQCD） factorization approach, we calculate the new physics contributions to the four B→Kη（＇） decays in the Standard Model （SM） with a fourth generation of fermions （SM4）, ...By employing the perturbative QCD （pQCD） factorization approach, we calculate the new physics contributions to the four B→Kη（＇） decays in the Standard Model （SM） with a fourth generation of fermions （SM4）, induced by the loop diagrams involving t＇ quark. Within the considered parameter space of the SM4 we find that： （a） the next-to-leading order （NLO） pQCD predictions for the branching ratios and CP-violating asymmetries in both the SM and SM4 generally agree with the data within one standard deviation; （b） for Br（B→Kη）, the inclusion of the fourth generation contributions can improve the agreement between the theoretical predictions and the data effectively; （c） however, for Br（B→Kη＇） the decrease due to t＇ loops is disfavored by the data; and, （d） the new physics corrections to the CP-violating asymmetries of the considered decays are only about 10%.展开更多
Over the last few years LHCb found some discrepancies in b → sl^＋l^-FCNC transitions, including anomalies in the angular observables of B→K^＊μ^＋μ^-, particularly in P′5, in the low dimuon mass region. Recently...Over the last few years LHCb found some discrepancies in b → sl^＋l^-FCNC transitions, including anomalies in the angular observables of B→K^＊μ^＋μ^-, particularly in P′5, in the low dimuon mass region. Recently,these anomalies have been confirmed by Belle, CMS and ATLAS. As direct evidence of physics beyond the Standard Model is absent so far, these anomalies are being interpreted as indirect hints of new physics. In this context, we study the implications of the family non-universal Z′ model for the angular observables P（1,2,3）, P′（4,5,6） and newly proposed lepton flavor universality violation observables, Q（4,5）, in the B → K^＊（→Kπ）μ^＋μ^-decay channel in the low dimuon mass region. To see the variation in the values of these observables from their Standard Model values, we have chosen different scenarios for the Z′ model. It is found that these angular observables are sensitive to the values of the parameters of the Z′ model. We have also found that with the present parametric space of the Z′ model,the P′5-anomaly could be accommodated. However, more statistics on the anomalies in the angular observables are helpful to reveal the status of the considered model and, in general, the nature of new physics.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
In this short review,we present the current status about the theoretical and experimental studies for some important semileptonic decays of B=Bsmesons.We firstly gave a brief introduction for the experimental measurem...In this short review,we present the current status about the theoretical and experimental studies for some important semileptonic decays of B=Bsmesons.We firstly gave a brief introduction for the experimental measurements for B=Bs!Peltl;l ml;m mT decays,the BaBar’s ReDT and ReD T anomaly,the P05deviation for B0!K 0ltl decay.We then made a careful discussion about the evaluations for the relevant form factors in the light-cone QCD sum rule,the heavy quark effective theory,and the perturbative QCD factorization approach.By using the form factors calculated in the perturbative(pQCD)approach,we then calculate and show the pQCD predictions for the decay rates of many semileptonic decays of B=Bsmesons.We also made careful phenomenological analysis for these pQCD predictions and found,in general,the following points:(a)For all the considered B=Bssemileptonic decays,the next-to-leading order pQCD predictions for their decay rates agree well with the data and those from other different theoretical methods;(b)For ReDT and ReD T,the pQCD predictions agree very well with the data,the BaBar’s anomaly of ReDe TT are therefore explained successfully in the standard model by employing the pQCD approach;and(c)We defined several new ratios Rl;s Dand Rl;s Ds,they may be more sensitive to the QCD dynamics which controls the B=Bs!eDe T;De T sT transitions than the old ratios,we therefore strongly suggest LHCb and the forthcoming Super-B experiments to measure these new ratios.展开更多
In this paper,we study the B→D^(*) l-l -ι semileptonic decays and calculate the branching ratios B(B→D^(*) l-l -ι) and the ratios R(D^(*)) and R_D^( l,s) by employing the perturbative QCD(pQCD)factorization appro...In this paper,we study the B→D^(*) l-l -ι semileptonic decays and calculate the branching ratios B(B→D^(*) l-l -ι) and the ratios R(D^(*)) and R_D^( l,s) by employing the perturbative QCD(pQCD)factorization approach.We find that(a)for R(D)and R(D*)ratios,the pQCD predictions are R(D)=0.430-0.026?0.021,R(D*)=0.301±0.013 and agree well with BaBar’s measurements of ReD e?T T;(b)for the newly defined R_D^1 and R_D^s ratios,the pQCD predictions are R_D^l=0.450-0.051+0.064 and R_D^s=0.642-0.070+0.081,which may be more sensitive to the QCD dynamics of the considered semileptonic decays than R(D^(*)) and should be tested by experimental measurements.展开更多
Along with the running of Large Hadron Collider(LHC)located at CERN in November 2009,a large number of data samples of Bc meson have been collected and some hadronic Bc decay modes have been measured by the LHC experi...Along with the running of Large Hadron Collider(LHC)located at CERN in November 2009,a large number of data samples of Bc meson have been collected and some hadronic Bc decay modes have been measured by the LHC experiments.In view of the special and important roles of Bc meson decays playing in the heavy flavor sector,we here give a short review on the status of two body hadronic decays Bc!M1M2at both experimental and theoretical aspects.For the theoretical progresses,specifically,we will show lots of theoretical studies on two body hadronic Bcdecays involving pseudoscalar,vector,scalar,axial-vector,even tensor meson(s)in the final states by employing the perturbative QCD(pQCD)factorization approach.We will present a general analysis about the twobody hadronic decays of the heavy Bc meson and also provide some expectations for the future developments.展开更多
基金Supported by Ministerio de Ciencia y Tecnología(FPA2007-65748)Junta de Castilla y León(SA-106A07,GR12)+1 种基金European Community-Research Infrastructure Integrating Activity"Study of Strongly Interacting Matter"(HadronPhysics2 Grant no.227431)Spanish Ingenio-Consolider 2010 Program CPAN(CSD2007-00042)
文摘We calculate the D s 1 （2536） ^＋ decays into D＊K channels,including the decay D s 1 （2536） ＋ → D ＋ π-K ＋ through a virtual D＊0 in a constituent quark model.Widths and S/D amplitudes ratio are in agreement with the recent Belle and BABAR data,being the results sensitive to 1 P 1 and 3 P 1 mixture.
文摘We present a preliminary measurement of the B（Ds→μvu） with the Belle experiment at the KEKB collider. We select Ds →μvu decays with a method that provides a high-purity of the selected sample and an absolute measurement of the branching fraction. The results are based on a data sample of 550 fb^-1 and are compared to similar measurements by other experiments as well as to the predictions of LQCD. We conclude with short prospects for improvements in the accuracy of the measurement.
基金supported in part by the National Natural Science Foundation of China (Grant Nos. 10935012, 10928510, 10821063 and 10775179)CAS Key Project on "τ-Charm Physics (Grant No. KJCX2-yw-N29)+1 种基金the Scientific Research Fund of GUCASthe Project of Knowledge Innovation Program (PKIP) of CAS (Grant No. KJCX2.YW.W10)
文摘It was found that the vector meson pair from the pseudoscalar decays can form an entangled state.In this work we give out detailed explanations on the polarization correlation of the two entangled vector mesons.It is demonstrated that an experimental test of the Clauser-Horne inequality can be carried out through measuring the azimuthal distribution of four pseudoscalars in the cascade decay ηc→ VV →(PP)(PP),and the measurement of this process is feasible with the current running experiments in tau-charm factory.Moreover,a brief discussion on the polarization correlation of the two vector mesons from B → VV decays is also presented.
基金Supported by National Natural Science Foundation of China(11235005)Project on Graduate Students Education and Innovation of Jiangsu Province(CXZZ13 0391)
文摘By employing the perturbative QCD （pQCD） factorization approach, we calculate the new physics contributions to the four B→Kη（＇） decays in the Standard Model （SM） with a fourth generation of fermions （SM4）, induced by the loop diagrams involving t＇ quark. Within the considered parameter space of the SM4 we find that： （a） the next-to-leading order （NLO） pQCD predictions for the branching ratios and CP-violating asymmetries in both the SM and SM4 generally agree with the data within one standard deviation; （b） for Br（B→Kη）, the inclusion of the fourth generation contributions can improve the agreement between the theoretical predictions and the data effectively; （c） however, for Br（B→Kη＇） the decrease due to t＇ loops is disfavored by the data; and, （d） the new physics corrections to the CP-violating asymmetries of the considered decays are only about 10%.
文摘Over the last few years LHCb found some discrepancies in b → sl^＋l^-FCNC transitions, including anomalies in the angular observables of B→K^＊μ^＋μ^-, particularly in P′5, in the low dimuon mass region. Recently,these anomalies have been confirmed by Belle, CMS and ATLAS. As direct evidence of physics beyond the Standard Model is absent so far, these anomalies are being interpreted as indirect hints of new physics. In this context, we study the implications of the family non-universal Z′ model for the angular observables P（1,2,3）, P′（4,5,6） and newly proposed lepton flavor universality violation observables, Q（4,5）, in the B → K^＊（→Kπ）μ^＋μ^-decay channel in the low dimuon mass region. To see the variation in the values of these observables from their Standard Model values, we have chosen different scenarios for the Z′ model. It is found that these angular observables are sensitive to the values of the parameters of the Z′ model. We have also found that with the present parametric space of the Z′ model,the P′5-anomaly could be accommodated. However, more statistics on the anomalies in the angular observables are helpful to reveal the status of the considered model and, in general, the nature of new physics.
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 (11235005 and 10975074)
文摘In this short review,we present the current status about the theoretical and experimental studies for some important semileptonic decays of B=Bsmesons.We firstly gave a brief introduction for the experimental measurements for B=Bs!Peltl;l ml;m mT decays,the BaBar’s ReDT and ReD T anomaly,the P05deviation for B0!K 0ltl decay.We then made a careful discussion about the evaluations for the relevant form factors in the light-cone QCD sum rule,the heavy quark effective theory,and the perturbative QCD factorization approach.By using the form factors calculated in the perturbative(pQCD)approach,we then calculate and show the pQCD predictions for the decay rates of many semileptonic decays of B=Bsmesons.We also made careful phenomenological analysis for these pQCD predictions and found,in general,the following points:(a)For all the considered B=Bssemileptonic decays,the next-to-leading order pQCD predictions for their decay rates agree well with the data and those from other different theoretical methods;(b)For ReDT and ReD T,the pQCD predictions agree very well with the data,the BaBar’s anomaly of ReDe TT are therefore explained successfully in the standard model by employing the pQCD approach;and(c)We defined several new ratios Rl;s Dand Rl;s Ds,they may be more sensitive to the QCD dynamics which controls the B=Bs!eDe T;De T sT transitions than the old ratios,we therefore strongly suggest LHCb and the forthcoming Super-B experiments to measure these new ratios.
基金supported by the National Natural Science Foundation of China(10975074 and 11235005)
文摘In this paper,we study the B→D^(*) l-l -ι semileptonic decays and calculate the branching ratios B(B→D^(*) l-l -ι) and the ratios R(D^(*)) and R_D^( l,s) by employing the perturbative QCD(pQCD)factorization approach.We find that(a)for R(D)and R(D*)ratios,the pQCD predictions are R(D)=0.430-0.026?0.021,R(D*)=0.301±0.013 and agree well with BaBar’s measurements of ReD e?T T;(b)for the newly defined R_D^1 and R_D^s ratios,the pQCD predictions are R_D^l=0.450-0.051+0.064 and R_D^s=0.642-0.070+0.081,which may be more sensitive to the QCD dynamics of the considered semileptonic decays than R(D^(*)) and should be tested by experimental measurements.
基金supported by the National Natural Science Foundation of China (11205072,10975074 and 11235005)
文摘Along with the running of Large Hadron Collider(LHC)located at CERN in November 2009,a large number of data samples of Bc meson have been collected and some hadronic Bc decay modes have been measured by the LHC experiments.In view of the special and important roles of Bc meson decays playing in the heavy flavor sector,we here give a short review on the status of two body hadronic decays Bc!M1M2at both experimental and theoretical aspects.For the theoretical progresses,specifically,we will show lots of theoretical studies on two body hadronic Bcdecays involving pseudoscalar,vector,scalar,axial-vector,even tensor meson(s)in the final states by employing the perturbative QCD(pQCD)factorization approach.We will present a general analysis about the twobody hadronic decays of the heavy Bc meson and also provide some expectations for the future developments.
