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 THE PHYSICS PROSPECTS AND STATUS OF THE LHCb EXPERIMENT

2008 ◽  
Vol 23 (21) ◽  
pp. 3329-3333
Author(s):  
◽  
NEVILLE HARNEW
Keyword(s):  
Standard Model ◽  
Decay Mode ◽  
B Physics ◽  
Rare Decay ◽  
Lhcb Experiment ◽  
Decay Modes ◽  
Complementary Methods ◽  
Model Predictions

This paper summarises the B-physics prospects of the LHCb experiment. The focus is on the uniqueness of LHCb over and above the B-factories and the Tevatron experiments: the measurement of the unitarity angle γ using a number of complementary methods, the measurement of the [Formula: see text] mixing phase φs in tree and penguin decay modes, and the expected observation of the rare decay mode [Formula: see text] below Standard Model predictions.

scholarly journals K → μ+μ− as a clean probe of short-distance physics

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Avital Dery ◽  
Mitrajyoti Ghosh ◽  
Yuval Grossman ◽  
Stefan Schacht
Keyword(s):  
Matrix Element ◽  
Standard Model ◽  
Short Distance ◽  
Time Dependent ◽  
Final States ◽  
Interference Effects ◽  
Fundamental Theory ◽  
Long Distance ◽  
Ckm Matrix ◽  
The Standard Model

Abstract The K → μ+μ− decay is often considered to be uninformative of fundamental theory parameters since the decay is polluted by long-distance hadronic effects. We demonstrate that, using very mild assumptions and utilizing time-dependent interference effects, ℬ(KS → μ+μ−)ℓ=0 can be experimentally determined without the need to separate the ℓ = 0 and ℓ = 1 final states. This quantity is very clean theoretically and can be used to test the Standard Model. In particular, it can be used to extract the CKM matrix element combination $$ \mid {V}_{ts}{V}_{td}\sin \left(\beta +{\beta}_s\right)\mid \approx \mid {A}^2{\lambda}^5\overline{\eta}\mid $$ ∣ V ts V td sin β + β s ∣ ≈ ∣ A 2 λ 5 η ¯ ∣ with hadronic uncertainties below 1%.

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.

CHARM MIXING AND CP VIOLATION AT B-FACTORIES

2014 ◽  
Vol 35 ◽  
pp. 1460413
Author(s):  
GIANLUIGI CIBINETTO ◽  
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
New Physics ◽  
Ratio Analysis ◽  
Charm Meson ◽  
Final State ◽  
Charm Decays ◽  
Decay Modes ◽  
The Standard Model ◽  
Model Predictions

CP violation in charm decays is expected to be very small in the Standard Model, at the level of 0.1% or less. A sizable excess of CP violation with respect to the Standard Model predictions could be a signature of new physics. We report on recent searches for CP violation in charm meson decays at BABAR and Belle experiments. In particular we report a lifetime ratio analysis of D0 → K+K−, π+π− with respect to D0 → K−π+ decays, which is sensitive to [Formula: see text] mixing and CP violation. We report also on searches for CPV in the 3-body D+ → K+K−π+ decay and for decay modes with a [Formula: see text] in the final state, such as [Formula: see text].

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 The fate of $$\mathbf{V}_\mathbf{1}$$ vector leptoquarks: the impact of future flavour data

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
C. Hati ◽  
J. Kriewald ◽  
J. Orloff ◽  
A. M. Teixeira
Keyword(s):  
Simplified Model ◽  
Meson Decay ◽  
Final States ◽  
Decay Modes ◽  
Flavour Violation ◽  
Belle Ii ◽  
The Impact ◽  
Lepton Flavour ◽  
Model Approach

AbstractMotivated by the recent experimental progress on the B-meson decay anomalies (in particular the angular observables in $$B\rightarrow K^*\mu \mu $$ B → K ∗ μ μ ), we rely on a simplified-model approach to study the prospects of vector leptoquarks in what concerns numerous flavour observables, identifying several promising decay modes which would allow to (indirectly) probe such an extension. Our findings suggest that the confirmation of the B-meson decay anomalies, in parallel with positive signals (at Belle II or LHCb) for $$\tau \rightarrow \phi \mu $$ τ → ϕ μ , $$B_{(s)}$$ B ( s ) -meson decays to $$\tau ^+ \tau ^-$$ τ + τ - and $$\tau ^+ \mu ^-$$ τ + μ - ($$\tau ^+ e^-$$ τ + e - ) final states, as well as an observation of certain charged lepton flavour violation decays (at COMET or Mu2e), would contribute to strengthen the case for this scenario. We also illustrate how the evolution of the experimental determination of $$R_{D^{(*)}}$$ R D ( ∗ ) could be instrumental in falsifying an explanation of the anomalous B-meson decay data via a vector $$V_1$$ V 1 leptoquark.

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.

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.

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