CHARGED TGC FROM 1999 DELPHI DATA

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 299-301
Author(s):  
DIMITRIS FASSOULIOTIS
Keyword(s):  
Standard Model ◽  
Gauge Boson ◽  
Final States ◽  
Dipole Coupling ◽  
Quadrupole Coupling ◽  
The Standard Model ◽  
Model Predictions ◽  
Gauge Boson Couplings

Measurements of the trilinear gauge boson couplings WWγ and WWZ are presented from data taken by DELPHI in 1999 at an energy ranging from 192 to 202 GeV. Values are extracted with respect to [Formula: see text] and Δ κγ, the differences of the WWZ charge coupling and of the WWγ dipole coupling from their Standard Model values, and λγ, the WWγ quadrupole coupling. The study uses data from the final states jjℓν, jjjj, ℓX, jjX and γX, where j represents a quark jet, l an identified lepton and X missing four-momentum. The observations are consistent with the Standard Model predictions.

scholarly journals Trilinear gauge boson couplings in the standard model with one universal extra dimension

2013 ◽  
Vol 88 (1) ◽  
Author(s):  
M. A. López-Osorio ◽  
E. Martínez-Pascual ◽  
J. Montaño ◽  
H. Novales-Sánchez ◽  
J. J. Toscano ◽  
...  
Keyword(s):  
Standard Model ◽  
Gauge Boson ◽  
Extra Dimension ◽  
Universal Extra Dimension ◽  
The Standard Model ◽  
Gauge Boson Couplings

INDIRECT CONSTRAINTS ON THE TRIPLE GAUGE BOSON COUPLINGS FROM $\bm{Z\to b{\bar b}}$ PARTIAL WIDTH: AN UPDATE

2000 ◽  
Vol 15 (01) ◽  
pp. 1-7 ◽  
Author(s):  
O. J. P. ÉBOLI ◽  
M. C. GONZALEZ-GARCIA ◽  
S. F. NOVAES
Keyword(s):  
Gauge Boson ◽  
Partial Width ◽  
Boson Mass ◽  
Higgs Boson Mass ◽  
Present Value ◽  
Triple Gauge Couplings ◽  
The Standard Model ◽  
Model Predictions ◽  
Anomalous Triple Gauge Couplings ◽  
Gauge Boson Couplings

We update the indirect bounds on anomalous triple gauge couplings coming from the non-universal one-loop contributions to the [Formula: see text] width. These bounds, which are independent of the Higgs boson mass, are in agreement with the standard model predictions for the gauge boson self-couplings since the present value of Rb agrees fairly well with the theoretical estimates. Moreover, these indirect constraints on [Formula: see text] and [Formula: see text] are most stringent than the present direct bounds on these quantities, while the indirect limit on λZ is weaker than the available experimental data.

scholarly journals TRILINEAR NEUTRAL GAUGE BOSON COUPLINGS

2001 ◽  
Vol 16 (30) ◽  
pp. 4891-4909 ◽  
Author(s):  
DEBAJYOTI CHOUDHURY ◽  
SUKANTA DUTTA ◽  
SUBHENDU RAKSHIT ◽  
SAURABH RINDANI
Keyword(s):  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
Gauge Boson ◽  
Form Factors ◽  
Neutral Gauge Boson ◽  
The Standard Model ◽  
Vector Bosons ◽  
Gauge Boson Couplings

We study the CP even trilinear neutral gauge boson vertices at one-loop in the context of the Standard Model and the Minimal Supersymmetric Standard Model, assuming two of the vector bosons are on-shell. We also study the changes in the form-factors when these two bosons are off-shell.

scholarly journals Search for chargino–neutralino pair production in final states with three leptons and missing transverse momentum in $$\sqrt{s} = 13$$ TeV pp collisions with the ATLAS detector

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
G. Aad ◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
K. Abeling ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Standard Model ◽  
Pair Production ◽  
Atlas Detector ◽  
Higgs Bosons ◽  
Final States ◽  
Significant Excess ◽  
Missing Transverse Momentum ◽  
The Standard Model ◽  
Model Predictions

AbstractA search for chargino–neutralino pair production in three-lepton final states with missing transverse momentum is presented. The study is based on a dataset of $$\sqrt{s} = 13$$ s = 13  TeV pp collisions recorded with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 139 $$\hbox {fb}^{-1}$$ fb - 1 . No significant excess relative to the Standard Model predictions is found in data. The results are interpreted in simplified models of supersymmetry, and statistically combined with results from a previous ATLAS search for compressed spectra in two-lepton final states. Various scenarios for the production and decay of charginos ($${\tilde{\chi }}^\pm _1$$ χ ~ 1 ± ) and neutralinos ($${\tilde{\chi }}^0_2$$ χ ~ 2 0 ) are considered. For pure higgsino $${\tilde{\chi }}^\pm _1{\tilde{\chi }}^0_2$$ χ ~ 1 ± χ ~ 2 0 pair-production scenarios, exclusion limits at 95% confidence level are set on $${\tilde{\chi }}^0_2$$ χ ~ 2 0 masses up to 210 GeV. Limits are also set for pure wino $${\tilde{\chi }}^\pm _1{\tilde{\chi }}^0_2$$ χ ~ 1 ± χ ~ 2 0 pair production, on $${\tilde{\chi }}^0_2$$ χ ~ 2 0 masses up to 640 GeV for decays via on-shell W and Z bosons, up to 300 GeV for decays via off-shell W and Z bosons, and up to 190 GeV for decays via W and Standard Model Higgs bosons.

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 Flavour Anomalies in a U(1) SUSY Extension of the SM

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 191
Author(s):  
Alexander Bednyakov ◽  
Alfiia Mukhaeva
Keyword(s):  
Standard Model ◽  
Parameter Space ◽  
Gauge Boson ◽  
New Physics ◽  
Low Energy ◽  
Effective Theory ◽  
The Standard Model ◽  
Meson Mixing ◽  
Additional Anomaly ◽  
Lepton Flavour

Flavour anomalies have attracted a lot of attention over recent years as they provide unique hints for possible New Physics. Here, we consider a supersymmetric (SUSY) extension of the Standard Model (SM) with an additional anomaly-free gauge U(1) group. The key feature of our model is the particular choice of non-universal charges to the gauge boson Z′, which not only allows a relaxation of the flavour discrepancies but, contrary to previous studies, can reproduce the SM mixing matrices both in the quark and lepton sectors. We pay special attention to the latter and explicitly enumerate all parameters relevant for our calculation in the low-energy effective theory. We find regions in the parameter space that satisfy experimental constraints on meson mixing and LHC Z′ searches and can alleviate the flavour anomalies. In addition, we also discuss the predictions for lepton-flavour violating decays B+→K+μτ and B+→K+eτ.

TeV Scale B – L Phenomenology at LHC

2007 ◽  
Vol 22 (31) ◽  
pp. 5889-5908 ◽  
Author(s):  
M. Abbas ◽  
W. Emam ◽  
S. Khalil ◽  
M. Shalaby
Keyword(s):  
Standard Model ◽  
Gauge Boson ◽  
Cross Sections ◽  
Branching Ratios ◽  
Higgs Production ◽  
Neutrino Masses ◽  
Natural Explanation ◽  
The Standard Model ◽  
The Cross

We present the phenomenology of the low scale U(1)B–L extension of the standard model and its implications at LHC. We show that this model provides a natural explanation for the presence of three right-handed neutrinos and can naturally account the observed neutrino masses and mixing. We study the decay and production of the extra gauge boson and the SM singlet scalar (heavy Higgs) predicted in this type of models. We find that the cross sections of the SM-like Higgs production are reduced by ~ 20% – 30%, while its decay branching ratios remain intact. The extra Higgs has relatively small cross sections and the branching ratios of Z′ → l+l− are of order ~ 20% compared to ~ 3% of the SM results.

scholarly journals RECENT τ LEPTON RESULTS FROM BABAR

2014 ◽  
Vol 35 ◽  
pp. 1460440
Author(s):  
ALBERTO LUSIANI
Keyword(s):  
Standard Model ◽  
Branching Fractions ◽  
Charged Particles ◽  
Babar Collaboration ◽  
Final States ◽  
Final State ◽  
Experimental Knowledge ◽  
Electron Positron ◽  
The Standard Model ◽  
Positron Collisions

We report recent measurements on τ leptons obtained by the BABAR collaboration using the entire recorded sample of electron-positron collisions at and around the Υ(4S) (about 470fb-1). The events were recorded at the PEP-II asymmetric collider at the SLAC National Accelerator Laboratory. The measurements include high multiplicity τ decay branching fractions with 3 or 5 charged particles in the final state, a search for the second class current the τ decay τ → πη′ν, τ branching fractions into final states containing two KS mesons, [Formula: see text], with h = π, K, and preliminary measurements of hadronic spectra of τ decays with three hadrons (τ- → h-h+h-ντ decays, where h = π, K). The results improve the experimental knowledge of the τ lepton properties and can be used to improve the precision tests of the Standard Model.

SEARCH FOR NEW PHYSICS IN eμX DATA AT THE TEVATRON USING SLEUTH: A QUASI-MODEL-INDEPENDENT SEARCH STRATEGY FOR NEW PHYSICS

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 888-890
Author(s):  
◽  
BRUCE KNUTESON
Keyword(s):  
Standard Model ◽  
Search Strategy ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Final States ◽  
Final State ◽  
The Standard Model ◽  
Model Independent

We present a quasi-model-independent search for physics beyond the standard model. We define final states to be studied, and construct a rule that identifies a set of variables appropriate for any particular final state. A new algorithm ("Sleuth") searches for regions of excess in the space of those variables and quantifies the significance of any detected excess. After demonstrating the sensititvity of the method, we apply it to the semi-inclusive channel eμX collected in ≈108 pb -1 of [Formula: see text] collisions at [Formula: see text] at the DØ experiment at the Fermilab Tevatron. We find no evidence of new high pT physics in this sample.

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