Using the form factors calculated in the three-point QCD sum rules, we calculate the new physics contri- butions to the physical observables of Bc→D;μ＋ μ- decay in a family non-universal Z＇ model. Under the consi...Using the form factors calculated in the three-point QCD sum rules, we calculate the new physics contri- butions to the physical observables of Bc→D;μ＋ μ- decay in a family non-universal Z＇ model. Under the consideration of three cases of the new physics parameters, we find that： （a） the Z＇ boson can provide large contributions to the differential decay rates; （b） the forward-backward asymmetry （FBA） can be increased by about 47%, 38%, and 110% at most in S1, S2, and extreme limR values （ELV）, respectively. In addition, the zero crossing can be shifted in all the cases; （c） when s 〉 0.08, the value Of PL can be changed from -1 in the Standard Model （SM） to -0.5 in S1, -0.6 in S2, and 0 in extreme limit values, respectively; （d） the new physics corrections to PT will decrease the SM prediction about 25% for the cases of S1 and S2, 100% for the case of ELV.展开更多
We analyze different decay observables of semileptonic decays Bc→(Ds,d(*))μ+μ-,such as the branching ratio,forward-backward asymmetry,polarization fraction,and lepton polarization asymmetry in the non-universal Z’...We analyze different decay observables of semileptonic decays Bc→(Ds,d(*))μ+μ-,such as the branching ratio,forward-backward asymmetry,polarization fraction,and lepton polarization asymmetry in the non-universal Z’model.We further study the dependence of the branching fraction to the new model parameters and find that the values of different decay parameters increase in the Z’model,which indicates a possible approach for the search of new physics as well as for the unknown phenomena of the charm B meson.展开更多
In contrast with B0-ˉB0, Bs-ˉBs mixing where the standard model（SM） contributions overwhelm that of the new physics beyond standard model（BSM）, a measured relatively large D0-ˉD0mixing where the SM contribution...In contrast with B0-ˉB0, Bs-ˉBs mixing where the standard model（SM） contributions overwhelm that of the new physics beyond standard model（BSM）, a measured relatively large D0-ˉD0mixing where the SM contribution is negligible, definitely implies the existence of the new physics BSM. It is natural to consider that the rare decays of D meson might be more sensitive to new physics, and the decay mode D0→μ＋μ-could be an ideal area to search for new physics because it is a flavor changing process. In this work we look for a trace of the new physics BSM in the leptonic decays of D0. Concretely we discuss the contributions of unparticle or an extra gauge boson Z while imposing the constraints set by fitting the D0-ˉD0mixing data. We find that the long-distance SM effects for D0→lˉl still exceed those contributions of the BSM under consideration, but for a double-flavor changing process such as D0→μ±e, the new physics contribution would be significant.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10947020 and 11147004Natural Science Foundation of Henan Province under Grant No. 112300410188
文摘Using the form factors calculated in the three-point QCD sum rules, we calculate the new physics contri- butions to the physical observables of Bc→D;μ＋ μ- decay in a family non-universal Z＇ model. Under the consideration of three cases of the new physics parameters, we find that： （a） the Z＇ boson can provide large contributions to the differential decay rates; （b） the forward-backward asymmetry （FBA） can be increased by about 47%, 38%, and 110% at most in S1, S2, and extreme limR values （ELV）, respectively. In addition, the zero crossing can be shifted in all the cases; （c） when s 〉 0.08, the value Of PL can be changed from -1 in the Standard Model （SM） to -0.5 in S1, -0.6 in S2, and 0 in extreme limit values, respectively; （d） the new physics corrections to PT will decrease the SM prediction about 25% for the cases of S1 and S2, 100% for the case of ELV.
基金DST,Govt.of India for the INSPIRE Fellowship(IF160115)SERB,DST,Govt.of India for financial support through project(EMR/2015/000817)。
文摘We analyze different decay observables of semileptonic decays Bc→(Ds,d(*))μ+μ-,such as the branching ratio,forward-backward asymmetry,polarization fraction,and lepton polarization asymmetry in the non-universal Z’model.We further study the dependence of the branching fraction to the new model parameters and find that the values of different decay parameters increase in the Z’model,which indicates a possible approach for the search of new physics as well as for the unknown phenomena of the charm B meson.
基金Supported by National Natural Science Foundation of China(11375128)
文摘In contrast with B0-ˉB0, Bs-ˉBs mixing where the standard model（SM） contributions overwhelm that of the new physics beyond standard model（BSM）, a measured relatively large D0-ˉD0mixing where the SM contribution is negligible, definitely implies the existence of the new physics BSM. It is natural to consider that the rare decays of D meson might be more sensitive to new physics, and the decay mode D0→μ＋μ-could be an ideal area to search for new physics because it is a flavor changing process. In this work we look for a trace of the new physics BSM in the leptonic decays of D0. Concretely we discuss the contributions of unparticle or an extra gauge boson Z while imposing the constraints set by fitting the D0-ˉD0mixing data. We find that the long-distance SM effects for D0→lˉl still exceed those contributions of the BSM under consideration, but for a double-flavor changing process such as D0→μ±e, the new physics contribution would be significant.
