scholarly journals investigation of Total Branching Ratio and the Lepton Polarization Asymmetries in Bs → ϕℓ+ℓ− Decay with the Fourth-Generation SM

2017 ◽  
Vol 4 (ICBS Conference) ◽  
pp. 637-659
Author(s):  
H Mehranfar
Keyword(s):  
Branching Ratio ◽  
Fourth Generation ◽  
Lepton Polarization

scholarly journals THE B→Xsl+l- AND B→Xsγ DECAYS WITH THE FOURTH GENERATION

1999 ◽  
Vol 14 (35) ◽  
pp. 2453-2462 ◽  
Author(s):  
CHAO-SHANG HUANG ◽  
WU-JUN HUO ◽  
YUE-LIANG WU
Keyword(s):  
B Meson ◽  
Branching Ratio ◽  
Branching Ratios ◽  
Fourth Generation ◽  
B Meson Decays ◽  
Meson Decays

If the fourth generation fermions exist, the new quarks could influence the branching ratios of the decays of B→Xsγ and B→Xsl+l-. We obtain two solutions of the fourth generation CKM factor [Formula: see text] from the decay of B→ Xsγ. We use these two solutions to calculate the new contributions of the fourth generation quark to Wilson coefficients of the decay of B→ Xsl+l-. The branching ratio and the forward–backward asymmetry of the decay of B→ Xsl+l- in the two cases are calculated. Our results are quite different from that of SM in one case, almost the same in another case. If Nature chooses the former, the B meson decays could provide a possible test of the fourth generation existence.

CP ASYMMETRIES IN NONLEPTONIC DECAY OF NEUTRAL B MESONS FOR THREE AND FOUR GENERATIONS

1989 ◽  
Vol 04 (25) ◽  
pp. 2465-2471 ◽  
Author(s):  
TSUTOM HASUIKE ◽  
TOSHIHIKO HATTORI ◽  
TOSHIO HAYASHI ◽  
SEIICHI WAKAIZUMI
Keyword(s):  
Cp Violation ◽  
B Mesons ◽  
Branching Ratio ◽  
Fourth Generation ◽  
Nonleptonic Decay ◽  
Present Stage ◽  
Decay Modes ◽  
Quark Pairs ◽  
Mixing Parameter ◽  
O 10

We investigate the effects of CP violation in nonleptonic decays of neutral B mesons (Bd, Bs) in the Kobayashi-Maskawa model through the quark exchange diagram in terms of the Wolfenstein matrix. In our calculation, we use the new data of mixing parameter xd= 0.70±0.13 which is derived from ARGUS and CLEO measurements and the new data on the branching ratio for Bd meson. We obtain the results that CP violating asymmetries for Bd→D+D−, π+π− and K+K− reach about 50% and the number of [Formula: see text] quark pairs needed to detect the asymmetry is O(106~107) at 3σ level, and the asymmetries for [Formula: see text], D−π+, D0π0 and D+π− reach the order of 20% and the number of [Formula: see text] pairs is O(108). Therefore, we may conclude that the CP violation for these decay modes is possibly observable at the present stage. The effects of fourth generation quarks on CP violation are also studied.

Study of Λb → Λℓ+ℓ− (ℓ = e,μ,τ) decays in the G(221) model

2016 ◽  
Vol 31 (36) ◽  
pp. 1650197
Author(s):  
Shuai-Wei Wang
Keyword(s):  
Sum Rules ◽  
Branching Ratio ◽  
Form Factors ◽  
New Physics ◽  
Tree Level ◽  
Decay Channels ◽  
Flavor Changing ◽  
The Standard Model ◽  
Lepton Polarization ◽  
Text Model

We study respectively the baryonic semilepton decays [Formula: see text][Formula: see text] in the [Formula: see text] model, which includes the tree-level flavor-changing-neutral-currents (FCNCs) induced by [Formula: see text] and [Formula: see text] bosons and modifies the Wilson coefficients [Formula: see text] and [Formula: see text]. For the form factors, we use the results of QCD light-cone sum rules (LCSR) in the low [Formula: see text] region and lattice QCD in the high [Formula: see text] region, respectively. We consider the effects of this new physics (NP) model on some measured physical observables, like the differential branching ratio, the longitudinal polarization of the dilepton system, the lepton-side forward–backward asymmetry and the baryon-side forward–backward asymmetry, and find, obvious differences occur in some observables between the Standard Model (SM) and this NP model. Meanwhile, we also discuss the double lepton polarization asymmetries of these decay channels, and find, [Formula: see text], [Formula: see text] and [Formula: see text] of these decay channels are sensitive to the contribution of this NP model.

scholarly journals COMPLETE STUDY OF THE SEMILEPTONIC B TO $K_2^*(1430)$ DECAYS IN THE STANDARD MODEL WITH FOURTH GENERATION

2012 ◽  
Vol 27 (25) ◽  
pp. 1250149 ◽  
Author(s):  
MUHAMMAD JUNAID ◽  
MUHAMMAD JAMIL ASLAM ◽  
ISHTIAQ AHMED
Keyword(s):  
Standard Model ◽  
Form Factors ◽  
Experimental Information ◽  
Fourth Generation ◽  
Final State ◽  
Cp Asymmetry ◽  
The Standard Model ◽  
Complete Study ◽  
Lepton Polarization ◽  
State Formula

The [Formula: see text] decays are analyzed in the standard model (SM) extended to fourth generation of quarks (SM4). The decay rate, forward–backward asymmetry, lepton polarization asymmetries, the helicity fractions of the final state [Formula: see text] meson and CP asymmetry are discussed using the form factors calculated in the light-cone sum rules (LCSR) approach. We utilized the constraints on different fourth generation parameters obtained from the experimental information on K, B and D decays and from their recent searches at the ATLAS and CMS experiments to explore their impact on the [Formula: see text] decays. We find that the values of above mentioned physical observables deviate significantly from their minimal SM predications. In the present study, we will also perform the analysis of CP asymmetry in [Formula: see text] decays within SM4, which is one of the most interesting observable in the study of SM4.

331-Z′ mediated FCNC effects on b → dμ+μ− transitions

2018 ◽  
Vol 33 (36) ◽  
pp. 1850225
Author(s):  
Soram Robertson Singh ◽  
Barilang MAWLONG
Keyword(s):  
Standard Model ◽  
Neutral Current ◽  
Branching Ratio ◽  
Decay Modes ◽  
Flavor Changing ◽  
Flavor Changing Neutral Current ◽  
Quark Level ◽  
Lepton Polarization ◽  
Text Model ◽  
New Formula

We study the rare semileptonic [Formula: see text] and [Formula: see text] decay modes mediated by the quark level [Formula: see text] transition in this paper. We analyze observables such as the differential branching ratio, lepton polarization asymmetry and forward–backward asymmetry within the standard model in the large hadronic recoil region. We then analyze these observables within the 331 or [Formula: see text] model in which a new heavy [Formula: see text] boson contributes. The effects of the [Formula: see text]-mediated flavor changing neutral current (FCNC) transitions on these modes are examined by varying the mass [Formula: see text] and the model parameter [Formula: see text]. The new [Formula: see text] couplings are constrained by flavor observables of [Formula: see text] mixing. For the obtained parameter space, we observe [Formula: see text] sensitivities of our observables of interest and deviations from standard model can range from moderate to large depending on the [Formula: see text] value.

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