One-Loop Flavour-Changing Neutral Currents in the Standard Model

1990 ◽  
pp. 209-223
Author(s):  
A. Barroso
Keyword(s):  
Standard Model ◽  
Flavour Changing Neutral Currents ◽  
Neutral Currents ◽  
The Standard Model

scholarly journals Long-distance QCD effects in FCNC B → γl+l- decays

2018 ◽  
Vol 192 ◽  
pp. 00031 ◽  
Author(s):  
Anastasiia Kozachuk ◽  
Dmitri Melikhov ◽  
Nikolai Nikitin
Keyword(s):  
Standard Model ◽  
Recent Work ◽  
Flavour Changing Neutral Currents ◽  
Neutral Currents ◽  
Long Distance ◽  
Leptonic Decays ◽  
The Standard Model

This presentation reviews the main results of our recent work [1] on rare radiative leptonic decays Bd,s → γμ+μ- and Bd,s → γe+e- induced by flavour-changing neutral currents (FCNC) in the Standard Model.

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.

Flavour-changing neutral currents making and breaking the standard model

Nature ◽  
2017 ◽  
Vol 546 (7657) ◽  
pp. 221-226 ◽  
Author(s):  
F. Archilli ◽  
M.-O. Bettler ◽  
P. Owen ◽  
K. A. Petridis
Keyword(s):  
Standard Model ◽  
Flavour Changing Neutral Currents ◽  
Neutral Currents ◽  
The Standard Model

scholarly journals Generic one-loop matching conditions for rare meson decays

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Fady Bishara ◽  
Joachim Brod ◽  
Martin Gorbahn ◽  
Ulserik Moldanazarova
Keyword(s):  
Standard Model ◽  
Flavour Changing Neutral Currents ◽  
Neutral Currents ◽  
Matching Conditions ◽  
Meson Decays ◽  
Effective Lagrangian ◽  
The Standard Model

Abstract Leptonic and semileptonic meson decays that proceed via flavour-changing neutral currents provide excellent probes of physics of the standard model and beyond. We present explicit results for the Wilson coefficients of the weak effective Lagrangian for these decays in any perturbative model in which these processes proceed via one-loop contributions. We explicitly show that our results are finite and gauge independent, and provide Mathematica code that implements our results in an easily usable form.

scholarly journals Pentaquarks and possible anomalies at LHCb

2016 ◽  
Vol 31 (20n21) ◽  
pp. 1630032
Author(s):  
G. Lafferty
Keyword(s):  
Matrix Element ◽  
Standard Model ◽  
Meson Decay ◽  
Flavour Changing Neutral Currents ◽  
Neutral Currents ◽  
Ckm Matrix ◽  
Lhcb Experiment ◽  
Decay Modes ◽  
Model Predictions ◽  
Lepton Flavour

With the LHC Run 1 data, the LHCb experiment discovered two pentaquark states and has evidence for a number of possible anomalies in the flavour sector. The possible anomalies include indications of violations of lepton flavour universality, deviations from Standard Model predictions in several [Formula: see text]-meson decay modes that are mediated by flavour-changing neutral currents, and further evidence for a discrepancy between inclusive and exclusive measurements of the CKM matrix element [Formula: see text].

scholarly journals Neutral currents within beyond the standard model

1988 ◽  
Vol 297 (2) ◽  
pp. 244-286 ◽  
Author(s):  
G. Costa ◽  
J. Ellis ◽  
G.L. Fogli ◽  
D.V. Nanopoulos ◽  
F. Zwirner
Keyword(s):  
Standard Model ◽  
Beyond The Standard Model ◽  
Neutral Currents ◽  
The Standard Model

Μελέτη των διασπάσεων αλλαγής γεύσης ουδετέρου ρεύματος του top κουάρκ στα πλαίσια του πειράματος CMS/LHC

2007 ◽  
Author(s):  
Γρηγόριος Βερμίσογλου
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
Z Boson ◽  
New Physics ◽  
Flavour Changing Neutral Currents ◽  
Neutral Currents ◽  
Leptonic Decays ◽  
Quark Sector ◽  
Systematic Effects ◽  
Detector Simulation

This study contains the first realistic estimate for the CMS/LHC sensitivity to Flavour Changing Neutral Currents (FCNC) in the top quark sector. The non-Standard Model decays t→Zq and t→ γ q (where q = u, c) have been studied at √s = 14 TeV exploiting the leptonic decays of the Z⁰ boson and the photon. A realistic detector simulation has been used and the most important systematic effects have been addressed. The 5-sigma discovery limits for the two decays are BR(t→qZ)= 11.4 x 10⁻⁴ and BR(t→ γ q)= 5.7 x 10⁻⁴, allowing some models of new physics to be tested.

Charm Physics

2009 ◽  
Vol 24 (supp01) ◽  
pp. 499-502 ◽  
Author(s):  
D. M. Asner ◽  
I. I. Bigi ◽  
J. Charles ◽  
J. C. Chen ◽  
H. Y. Cheng ◽  
...  
Keyword(s):  
Standard Model ◽  
Quantum Number ◽  
Degrees Of Freedom ◽  
D Mesons ◽  
Low Frequency ◽  
Charm Physics ◽  
Neutral Currents ◽  
Long Distance ◽  
Flavor Changing ◽  
The Standard Model

Nobody doubts that the discovery of hadrons with charm of the hidden and open variety – i.e. charmonium as well as D mesons – was instrumental in the acceptance of the Standard Model (SM) in general, and of quarks as physical degrees of freedom, rather than objects of mere mathematical convenience, in particular. Yet charm is all too often viewed as a quantum number with a great past and with no particularly interesting future. This is due to SM predictions of a rather dull electroweak phenomenology of CKM parameters, a low frequency for [Formula: see text] oscillations, tiny (at best) CP asymmetries, and extremely rare flavor changing neutral currents which, in any case, are swamped by huge backgrounds from long-distance dynamics…

scholarly journals ISOLATED LEPTONS IN EVENTS WITH LARGE MISSING TRANSVERSE MOMENTUM AND THE SEARCH FOR SINGLE TOP PRODUCTION AT HERA

2006 ◽  
Vol 21 (25) ◽  
pp. 1901-1916 ◽  
Author(s):  
J. FERRANDO
Keyword(s):  
Transverse Momentum ◽  
Standard Model ◽  
New Physics ◽  
Beyond The Standard Model ◽  
High Transverse Momentum ◽  
Flavour Changing Neutral Currents ◽  
Proton Collisions ◽  
Missing Transverse Momentum ◽  
Single Top ◽  
The Standard Model

Recent results in searches for high transverse momentum leptons in events with large missing transverse momentum in electron–proton collisions at HERA are reviewed. These searches have implications for searches for physics beyond the Standard Model. The most recent results on searches for single top production via Flavour Changing Neutral Currents are reviewed. The consistency of results from the H1 and ZEUS collaborations and prospects of discovering new physics during the final year of HERA running are discussed.

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