scholarly journals SEMILEPTONIC $\Lambda_b\to\Lambda\nu\bar\nu$ DECAY IN THE LEPTOPHOBIC Z′ MODEL

2008 ◽  
Vol 23 (05) ◽  
pp. 347-358 ◽  
Author(s):  
B. B. ŞIRVANLI
Keyword(s):  
Z Boson ◽  
Neutral Current ◽  
Branching Ratio ◽  
New Physics ◽  
Experimental Measurements ◽  
Beyond The Standard Model ◽  
Flavor Changing ◽  
The Standard Model ◽  
Flavor Changing Neutral Current ◽  
Charged Leptons

We study the exclusive flavor changing neutral current process [Formula: see text] in the leptophobic Z′ model, where charged leptons do not couple to the extra Z′ boson. The branching ratio, as well as, the longitudinal, transversal and normal polarizations are calculated. It has been shown that all these physical observables are very sensitive to the existence of new physics beyond the standard model and their experimental measurements can give valuable information about it.

scholarly journals EFFECT OF BOTH Z AND Z′ MEDIATED FLAVOR-CHANGING NEUTRAL CURRENTS ON THE BARYONIC RARE DECAY Λb→Λℓ+ℓ-

2009 ◽  
Vol 24 (32) ◽  
pp. 6223-6235 ◽  
Author(s):  
S. SAHOO ◽  
C. K. DAS ◽  
L. MAHARANA
Keyword(s):  
Standard Model ◽  
Z Boson ◽  
Rare Decay ◽  
Branching Ratio ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Neutral Currents ◽  
Flavor Changing ◽  
The Standard Model ◽  
Flavor Changing Neutral Currents

We study the effect of both Z and Z′ mediated flavor-changing neutral currents (FCNCs) on the Λb→Λℓ+ℓ-(ℓ = μ, τ) rare decay. We find the branching ratio is reasonably enhanced from its Standard Model value due to the effect of both Z and Z′ mediated FCNCs, and gives the possibility of new physics beyond the Standard Model. The contribution of Z′ boson depends upon the precise value of MZ′.

THE EFFECT OF Z′-MEDIATED FLAVOR-CHANGING NEUTRAL CURRENT ON Bd→ℓ+ℓ- DECAY

2007 ◽  
Vol 22 (21) ◽  
pp. 1591-1599 ◽  
Author(s):  
S. SAHOO ◽  
L. MAHARANA
Keyword(s):  
Standard Model ◽  
Z Boson ◽  
Rare Decay ◽  
Neutral Current ◽  
Branching Ratio ◽  
New Physics ◽  
Flavor Changing ◽  
Flavor Changing Neutral Current

We study the effect of both Z and Z′-mediated flavor-changing neutral current (FCNC) on the Bd→ℓ+ℓ-, (ℓ = μ, τ) rare decay. We find that the branching ratio can be larger by order two from its Standard Model (SM) value due to the effect of both Z and Z′-mediated FCNC, though the major contribution comes from Z boson and provides signals for new physics beyond the SM.

Lepton flavor violating decays in model

2019 ◽  
Vol 97 (12) ◽  
pp. 1270-1276
Author(s):  
P. Nayek ◽  
P. Maji ◽  
S. Sahoo
Keyword(s):  
Standard Model ◽  
Neutral Current ◽  
Branching Ratios ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Lepton Flavor ◽  
Flavor Changing ◽  
The Standard Model ◽  
Flavor Changing Neutral Current ◽  
Text Model

Motivated by the hints of lepton flavor violating (LFV) decays, we study Bd,s → μτ, Bs,d → τe, and τ– → e– + e+ + e– decays in [Formula: see text] model. These LFV decays present interesting patterns that may reveal the shape of new physics beyond the standard model. Considering the effect of both Z- and [Formula: see text]-mediated flavor-changing neutral current we calculate the branching ratios for these decays. We find the branching ratios [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text].

scholarly journals Exotic leptons: Collider and muon magnetic moment constraints

2015 ◽  
Vol 30 (32) ◽  
pp. 1550187 ◽  
Author(s):  
D. Cogollo
Keyword(s):  
Magnetic Moment ◽  
Neutral Current ◽  
Gauge Bosons ◽  
Flavor Changing ◽  
Ongoing Effort ◽  
The Standard Model ◽  
Flavor Changing Neutral Current ◽  
Charged Leptons ◽  
Muon Magnetic Moment ◽  
The Masses

In light of the ongoing effort on reducing the theoretical uncertainties and an upcoming experiment concerning muon magnetic moment, we perform a detailed study of an 3-4-1 electroweak gauge extension of the standard model that contains exotic charged leptons in its spectrum. We discuss flavor changing neutral current, collider and electroweak bounds on the model and derive [Formula: see text] limits using current and projected limits on the muon magnetic moment. In summary, we exclude the masses of new gauge bosons that couple to muons and heavy charged leptons up to 700 GeV. Moreover, we find a projected lower bound on the scale of symmetry breaking to be 2 TeV.

scholarly journals RADIATIVE AND ELECTROWEAK RARE B DECAYS

2004 ◽  
Vol 19 (06) ◽  
pp. 934-948 ◽  
Author(s):  
M. NAKAO
Keyword(s):  
B Meson ◽  
Dominant Role ◽  
Rare Decay ◽  
Neutral Current ◽  
New Physics ◽  
Beyond The Standard Model ◽  
B Meson Decays ◽  
Meson Decays ◽  
Flavor Changing ◽  
Flavor Changing Neutral Current

This report summarizes the latest experimental results on radiative and electroweak rare B meson decays. These rare decay processes proceed through the Flavor-Changing-Neutral-Current processes, and thus are sensitive to the postulated new particles in the theories beyond the Standard Model. Experiments at e+e- colliders, Belle, BaBar and CLEO, have been playing the dominant role, while the CDF and D0 experiments have just started to provide new results from Tevatron Run-II. The most significant achievement is the first observation of the decay B→K*ℓ+ℓ-, which opens a new window to search for new physics in B meson decays.

scholarly journals Study of Bs0 → ℓ+ℓ−γ decays in a nonuniversal Z′ model

2019 ◽  
Vol 34 (09) ◽  
pp. 1950048 ◽  
Author(s):  
D. Banerjee ◽  
M. Kumar ◽  
P. Nayek ◽  
S. Sahoo
Keyword(s):  
Standard Model ◽  
Neutral Current ◽  
Branching Ratio ◽  
Branching Ratios ◽  
Flavor Changing ◽  
The Standard Model ◽  
Flavor Changing Neutral Current ◽  
Coupling Parameters ◽  
Text Model ◽  
Boson Coupling

We investigate [Formula: see text] decays in a nonuniversal [Formula: see text] model derived from the extension of the Standard Model (SM). Considering the [Formula: see text]-mediated flavor-changing neutral current (FCNC) effects, we calculate the branching ratio and forward–backward asymmetry [Formula: see text] for [Formula: see text] decay processes. We compare the obtained results with predictions of the SM and discuss the sensitivity of the observables to [Formula: see text] boson coupling parameters. We find that the branching ratios are enhanced by one order from SM predictions in [Formula: see text] model scenario. We also observe that the variation of forward–backward asymmetry with the [Formula: see text] boson coupling parameters portrays discrimination between NP effects and SM results.

scholarly journals RARE FCNC-B DECAYS AT HADRON MACHINES

1993 ◽  
Vol 08 (36) ◽  
pp. 3397-3411 ◽  
Author(s):  
DAVID B. CLINE
Keyword(s):  
Standard Model ◽  
Neutral Current ◽  
Cherenkov Light ◽  
Beyond The Standard Model ◽  
B Decays ◽  
Future Prospects ◽  
Novel Technique ◽  
Flavor Changing ◽  
The Standard Model ◽  
Flavor Changing Neutral Current

We review the current studies and future prospects for studies of Flavor Changing Neutral Current (FCNC) processes, emphasizing rare B decays. These experiments will be very sensitive to physics beyond the standard model. A key problem in these studies is the method to trigger the detector. We discuss a novel technique that uses an optical-Cherenkov light trigger to select events with significant impact parameters.

scholarly journals THE PREDICTION OF MASS OF Z′-BOSON FROM $B_q^0\hbox{--}\overline{B_q^0}$ MIXING

2011 ◽  
Vol 26 (20) ◽  
pp. 3347-3356 ◽  
Author(s):  
S. SAHOO ◽  
C. K. DAS ◽  
L. MAHARANA
Keyword(s):  
Standard Model ◽  
Z Boson ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Neutral Currents ◽  
Flavor Changing ◽  
The Standard Model ◽  
Near Future ◽  
Flavor Changing Neutral Currents

[Formula: see text] mixing offers a profound probe into the effects of new physics beyond the Standard Model. In this paper, [Formula: see text] and [Formula: see text] mass differences are considered taking the effect of both Z- and Z′-mediated flavor-changing neutral currents in the [Formula: see text] mixing (q = d, s). Our estimated mass of Z′ boson is accessible at the experiments LHC and B-factories in near future.

Investigating the 331-Z′ mediated FCNC effects on b → sμ+μ− transitions

2018 ◽  
Vol 33 (21) ◽  
pp. 1850125 ◽  
Author(s):  
Soram Robertson Singh ◽  
Barilang Mawlong ◽  
Ritu D’cruz
Keyword(s):  
Standard Model ◽  
Neutral Current ◽  
Branching Ratio ◽  
Decay Modes ◽  
Flavor Changing ◽  
The Standard Model ◽  
Flavor Changing Neutral Current ◽  
Lepton Polarization ◽  
Text Model ◽  
New Formula

The rare semileptonic [Formula: see text] and [Formula: see text] decay modes mediated by the [Formula: see text] transition are studied 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 low [Formula: see text] region. We then perform an analysis of the same modes 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 investigated 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 and branching ratio of [Formula: see text]. We find that for some values of these couplings, the observables are quite sensitive to [Formula: see text] effects and deviations from Standard Model can be large.

scholarly journals Status of rare exclusive B meson decays in 2018

2018 ◽  
Vol 33 (18n19) ◽  
pp. 1830016 ◽  
Author(s):  
Johannes Albrecht ◽  
Stefanie Reichert ◽  
Danny van Dyk
Keyword(s):  
B Meson ◽  
Experimental Situation ◽  
Neutral Current ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Lepton Flavor ◽  
Flavor Changing ◽  
Theoretical Status ◽  
Flavor Changing Neutral Current ◽  
B Quark

This review discusses the present experimental and theoretical status of rare flavor-changing neutral current b-quark decays at the beginning of 2018. It includes a discussion of the experimental situation and details of the currently observed anomalies in measurements of flavor observables, including lepton flavor universality. Progress on the theory side within and beyond the Standard Model theory is also discussed, together with potential New Physics interpretations of the present measurements.

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