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.

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 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 (g − 2)μ versus K → π + Emiss induced by the (B − L)23 boson

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Zhaofeng Kang ◽  
Yoshihiro Shigekami
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Neutral Current ◽  
Tree Level ◽  
Meson Decays ◽  
Loop Level ◽  
Flavor Changing ◽  
The Standard Model ◽  
Flavor Changing Neutral Current

Abstract To address the long-standing (g − 2)μ anomaly via a light boson, in ref. [1] we proposed to extend the standard model (SM) by the local (B − L)23, under which only the second and third generations of fermions are charged. It predicts an invisible Z′ with mass $$ \mathcal{O}(100) $$ O 100 MeV, and moreover it has flavor-changing neutral current (FCNC) couplings to the up-type quarks at tree level. Such a Z′, via KL→ π0 + Z′(→$$ v\overline{v} $$ v v ¯ ) at loop level, may be a natural candidate to account for the recent KOTO anomaly. In this article, we investigate this possibility, to find that Z′ can readily do this job if it is no longer responsible for the (g − 2)μ anomaly. We further find that both anomalies can be explained with moderate tuning of the CP violation, but may contradict the B meson decays.

scholarly journals RARE DECAYS: THEORY VS. EXPERIMENTS

2002 ◽  
Vol 17 (22) ◽  
pp. 3078-3097 ◽  
Author(s):  
GINO ISIDORI
Keyword(s):  
Experimental Study ◽  
Standard Model ◽  
Rare Decays ◽  
B Mesons ◽  
Neutral Current ◽  
Beyond The Standard Model ◽  
B Decays ◽  
The Standard Model ◽  
The Status

We present an overview of rare K, D and B decays. Particular attention is devoted to those flavour-changing neutral-current processes of K and B mesons that offer the possibility of new significant tests of the Standard Model. The sensitivity of these modes to physics beyond the Standard Model and the status of their experimental study are also discussed.

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.

THE INCLUSIVE SEMI-LEPTONIC $\bar B \to X_s \mu^+ \mu^-$ AND LEPTONIC $\bar{B}_s \rightarrow \mu^+ \mu^-$ DECAYS IN THE PRESENCE OF A LIGHT STABILIZED RADION IN RANDALL–SUNDRUM MODEL

2012 ◽  
Vol 27 (08) ◽  
pp. 1250043 ◽  
Author(s):  
PRASANTA KUMAR DAS
Keyword(s):  
Standard Model ◽  
Neutral Current ◽  
Belle Collaboration ◽  
Experimental Result ◽  
Limit Formula ◽  
Flavor Changing ◽  
The Standard Model ◽  
Flavor Changing Neutral Current ◽  
Inclusive Decay

The Belle collaboration has reported [Formula: see text] for the inclusive decay [Formula: see text]. Recently, the LHCb and the CMS collaboration has released the combined limit [Formula: see text]. The standard model results of the [Formula: see text] and [Formula: see text] are found to be within the 1σ of the experimental result. Taking a conservative viewpoint, we use these decays to constrain the braneworld Randall–Sundrum model. The stabilized radion in the Randall–Sundrum model, which is an electro-weak singlet, can cause the flavor changing neutral current (FCNC) b →s transition at the oneloop level. We investigate the possible impact of a stabilized radion on the above two decays and obtain the possible constraints on the radion vev 〈ϕ〉 for an ultra-light radion.

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 Revisiting the flavor changing neutral current Higgs decays $H\;\to \;{q}_{i}{q}_{j}$ in the Standard Model

2015 ◽  
Vol 42 (8) ◽  
pp. 085002 ◽  
Author(s):  
L G Benitez-Guzmán ◽  
I García-Jiménez ◽  
M A López-Osorio ◽  
E Martínez-Pascual ◽  
J J Toscano
Keyword(s):  
Standard Model ◽  
Neutral Current ◽  
Flavor Changing ◽  
The Standard Model ◽  
Flavor Changing Neutral Current

scholarly journals PREDICTIONS FOR $B \to \tau \bar{\mu} + \mu \bar{\tau}$

2013 ◽  
Vol 28 (31) ◽  
pp. 1350153 ◽  
Author(s):  
DRIS BOUBAA ◽  
ALAKABHA DATTA ◽  
MURUGESWARAN DURAISAMY ◽  
SHAABAN KHALIL
Keyword(s):  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
Neutral Current ◽  
Higgs Sector ◽  
New Physics ◽  
Flavor Changing ◽  
Clear Sign ◽  
Flavor Changing Neutral Current ◽  
Extended Higgs Sector

The observation of [Formula: see text] at present experiments would be a clear sign of new physics. In this paper, we calculate this process in an extended Higgs sector framework where the decay is mediated by the exchange of spin zero particle with flavor changing neutral current couplings. If we identify the scalar with the newly discovered state at LHC with a mass ~125 GeV then we find that, after imposing all experimental constraints, the [Formula: see text] can be as high as ~10-6 and [Formula: see text] can be as high as ~10-7. We also calculate this process in the minimal supersymmetric standard model and find the [Formula: see text] is typically of the order ~10-8.

scholarly journals Charming loops in exclusive rare FCNC B-decays

2019 ◽  
Vol 222 ◽  
pp. 01007 ◽  
Author(s):  
Dmitri Melikhov
Keyword(s):  
Standard Model ◽  
Gain Control ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Reliable Control ◽  
B Decays ◽  
Flavour Changing Neutral Currents ◽  
Neutral Currents ◽  
The Standard Model ◽  
Theoretical Predictions

Rare B-decays induced by flavour-changing neutral currents (FCNC) is one of the promising candidates for probing physics beyond the Standard model. However, for identifying potential new physics from the data, reliable control over QCD contributions is necessary. We focus on one of such QCD contributions – the charming loops – that potentially can lead to difficulties in disentangling new physics effects from the observable and discuss the possibility to gain control over theoretical predictions for charming loops.

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