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 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].

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].

scholarly journals SPECTATOR EFFECTS IN THE DECAY B→Kγγ

2005 ◽  
Vol 20 (17) ◽  
pp. 4079-4084 ◽  
Author(s):  
A. YU. IGNATIEV ◽  
G. C. JOSHI ◽  
B. H. J. MCKELLAR
Keyword(s):  
Standard Model ◽  
Decay Mode ◽  
Short Distance ◽  
Enhancement Factor ◽  
Rare Decay ◽  
Branching Ratio ◽  
The Spectator

We report the results of the first computation related to the study of the spectator effects in the rare decay mode B→Kγγ within the framework of Standard Model. It is found that the account of these effects results in the enhancement factor for the short-distance reducible contribution to the branching ratio.

scholarly journals Collider signatures of coannihilating dark matter in light of the B-physics anomalies

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Michael J. Baker ◽  
Darius A. Faroughy ◽  
Sokratis Trifinopoulos
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Bound States ◽  
B Physics ◽  
Search Strategy ◽  
Dark Matter Candidate ◽  
Final States ◽  
Dark Sector ◽  
Decay Modes ◽  
The Standard Model

Abstract Motivated by UV explanations of the B-physics anomalies, we study a dark sector containing a Majorana dark matter candidate and a coloured coannihilation partner, connected to the Standard Model predominantly via a U1 vector leptoquark. A TeV scale U1 leptoquark, which couples mostly to third generation fermions, is the only successful single-mediator description of the B-physics anomalies. After calculating the dark matter relic surface, we focus on the most promising experimental avenue: LHC searches for the coloured coannihilation partner. We find that the coloured partner hadronizes and forms meson-like bound states leading to resonant signatures at colliders reminiscent of the quarkonia decay modes in the Standard Model. By recasting existing dilepton and monojet searches we exclude coannihilation partner masses less than 280 GeV and 400 GeV, respectively. Since other existing collider searches do not significantly probe the parameter space, we propose a new dedicated search strategy for pair production of the coloured partner decaying into bbττ final states and dark matter particles. This search is expected to probe the model up to dark matter masses around 600 GeV with current luminosity.

scholarly journals BELLE B PHYSICS RESULTS

2002 ◽  
Vol 17 (22) ◽  
pp. 2967-2981 ◽  
Author(s):  
◽  
H. TAJIMA
Keyword(s):  
B Physics ◽  
Rare Decay ◽  
Matrix Elements ◽  
Decay Modes ◽  
Electroweak Penguin ◽  
Belle Experiment

B physics results from the Belle experiment are reviewed. Precise measurements of Cabbibo-Kobayashi-Maskawa matrix elements are made. Several decay modes are observed which will enable us to measure the CP angles ϕi in channels other than B0 → ψK0 modes. New rare decay modes are observed in many channels. Particular attention is paid to the first observation of the electroweak penguin-mediated decay.

scholarly journals Angular analysis of the rare decay $$ {B}_s^0 $$ → ϕμ+μ−

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
◽  
R. Aaij ◽  
A. S. W. Abdelmotteleb ◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
...  
Keyword(s):  
Standard Model ◽  
Invariant Mass ◽  
Rare Decay ◽  
Angular Distributions ◽  
Proton Collision ◽  
Centre Of Mass ◽  
Proton Proton ◽  
Angular Analysis ◽  
Model Predictions ◽  
Proton Proton Collision

Abstract An angular analysis of the rare decay $$ {B}_s^0 $$ B s 0 → ϕμ+μ− is presented, using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 8.4 fb−1. The observables describing the angular distributions of the decay $$ {B}_s^0 $$ B s 0 → ϕμ+μ− are determined in regions of q2, the square of the dimuon invariant mass. The results are consistent with Standard Model predictions.

scholarly journals First measurement of the $$C\!P$$-violating phase in $${{B} ^0_{s}} \!\rightarrow {{J /\psi }} ($$ $$\rightarrow $$ $$e ^+e ^-$$)$$\phi $$ decays

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
◽  
R. Aaij ◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
B. Adeva ◽  
...  
Keyword(s):  
Standard Model ◽  
Time Dependent ◽  
Centre Of Mass ◽  
Final State ◽  
Lhcb Experiment ◽  
Angular Analysis ◽  
The Standard Model ◽  
Model Predictions ◽  
First Time ◽  
Gamma S

AbstractA flavour-tagged time-dependent angular analysis of $${{B} ^0_{s}} \!\rightarrow {{J /\psi }} \phi $$ B s 0 → J / ψ ϕ decays is presented where the $${J /\psi }$$ J / ψ meson is reconstructed through its decay to an $$e ^+e ^-$$ e + e - pair. The analysis uses a sample of pp collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and $$8\text {\,Te V} $$ 8 \,Te V , corresponding to an integrated luminosity of $$3 \text {\,fb} ^{-1} $$ 3 \,fb - 1 . The $$C\!P$$ C P -violating phase and lifetime parameters of the $${B} ^0_{s} $$ B s 0 system are measured to be $${\phi _{{s}}} =0.00\pm 0.28\pm 0.07\text {\,rad}$$ ϕ s = 0.00 ± 0.28 ± 0.07 \,rad , $${\Delta \Gamma _{{s}}} =0.115\pm 0.045\pm 0.011\text {\,ps} ^{-1} $$ Δ Γ s = 0.115 ± 0.045 ± 0.011 \,ps - 1 and $${\Gamma _{{s}}} =0.608\pm 0.018\pm 0.012\text {\,ps} ^{-1} $$ Γ s = 0.608 ± 0.018 ± 0.012 \,ps - 1 where the first uncertainty is statistical and the second systematic. This is the first time that $$C\!P$$ C P -violating parameters are measured in the $${{B} ^0_{s}} \!\rightarrow {{J /\psi }} \phi $$ B s 0 → J / ψ ϕ decay with an $$e ^+e ^-$$ e + e - pair in the final state. The results are consistent with previous measurements in other channels and with the Standard Model predictions.

scholarly journals Strong constraints on the b → sγ photon polarisation from B0 → K*0e+e− decays

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
R. Aaij ◽  
◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
B. Adeva ◽  
...  
Keyword(s):  
Standard Model ◽  
Virtual Photon ◽  
Lhcb Experiment ◽  
Longitudinal Polarisation ◽  
Angular Analysis ◽  
Model Predictions ◽  
Integrated Luminosity

Abstract An angular analysis of the B0 → K*0e+e− decay is performed using a data sample corresponding to an integrated luminosity of 9 fb−1 of pp collisions collected with the LHCb experiment. The analysis is conducted in the very low dielectron mass squared (q2) interval between 0.0008 and 0.257 GeV2, where the rate is dominated by the B0 → K*0γ transition with a virtual photon. The fraction of longitudinal polarisation of the K*0 meson, FL, is measured to be FL = (4.4 ± 2.6 ± 1.4)%, where the first uncertainty is statistical and the second systematic. The $$ {A}_{\mathrm{T}}^{\mathrm{Re}} $$ A T Re observable, which is related to the lepton forward-backward asymmetry, is measured to be $$ {A}_{\mathrm{T}}^{\mathrm{Re}} $$ A T Re = −0.06 ± 0.08 ± 0.02. The $$ {A}_{\mathrm{T}}^{(2)} $$ A T 2 and $$ {A}_{\mathrm{T}}^{\mathrm{Im}} $$ A T Im transverse asymmetries, which are sensitive to the virtual photon polarisation, are found to be $$ {A}_{\mathrm{T}}^{(2)} $$ A T 2 = 0.11 ± 0.10 ± 0.02 and $$ {A}_{\mathrm{T}}^{\mathrm{Im}} $$ A T Im = 0.02 ± 0.10 ± 0.01. The results are consistent with Standard Model predictions and provide the world’s best constraint on the b → sγ photon polarisation.

scholarly journals FURTHER STUDIES OF HIGGS PROPERTIES AT AN ILC γγ COLLIDER

2013 ◽  
Vol 28 (18) ◽  
pp. 1350085 ◽  
Author(s):  
XIAO-GANG HE ◽  
SIAO-FONG LI ◽  
HSIU-HSIEN LIN
Keyword(s):  
Angular Distribution ◽  
Higgs Boson ◽  
Standard Model ◽  
Decay Mode ◽  
Branching Ratio ◽  
Current Data ◽  
Decay Modes ◽  
The Standard Model ◽  
Shell Production

Recently the ATLAS and CMS experiments at the LHC have found a Higgs-like boson h with a mass around 125 GeV from several decay modes. The decay mode h →γγ is one of the most important modes in studying whether h is actually the Standard Model (SM) Higgs boson. Current data indicate that h→γγ has a branching ratio larger than the SM prediction for h being identified as the SM Higgs boson. To decide whether the h discovered at the LHC is the SM Higgs boson, more data are needed. We study how γγ collider can help to provide some of the most important information about the Higgs boson properties. We show that a γγ collider can easily verify whether the enhanced h →γγ observed at the LHC hold. Different models can be tested by studying Higgs boson decay to γZ. Studying angular distribution of the γγ through on-shell production of h and its subsequent decays into a γγ pair can decide whether the Higgs-like boson h at the LHC is a spin-0 or a spin-2 boson.

Note on possible rare decay modes for elementary particles

1960 ◽  
Vol 15 (6) ◽  
pp. 934-936 ◽  
Author(s):  
E. Galzenati ◽  
M. Marinaro ◽  
S. Okubo
Keyword(s):  
Rare Decay ◽  
Elementary Particles ◽  
Decay Modes
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