scholarly journals Observables for model-independent detections of Z′ boson at the ILC

2015 ◽  
Vol 30 (16) ◽  
pp. 1550087
Author(s):  
V. Skalozub ◽  
I. Kucher
Keyword(s):  
Cross Section ◽  
Z Boson ◽  
Axial Vector ◽  
Effective Lagrangian ◽  
The Standard Model ◽  
Model Predictions ◽  
Model Independent ◽  
Vector Formula ◽  
Two Parameter

The integral observables for model-independent detections of Abelian Z′ gauge boson in e+e- → μ+μ-(τ+τ-) process with unpolarized beams at the ILC energies are proposed. They are based on the differential cross-section of deviations from the standard model predictions calculated with a low energy effective Lagrangian and taking into consideration the relations between the Z′ couplings to the fermions derived already. Due to these relations, the cross-section exhibits angular distribution giving a possibility for introducing one- or two-parameter observables which effectively fit the mass mZ′, the axial-vector [Formula: see text] and the product of vector couplings vevμ(vevτ). A discovery reach for the Z′ is estimated for two of introduced observables. Determination of the basic Z′ model is discussed. Comparison with other results and approaches is given.

RENORMALIZABILITY AND SEARCHING FOR THE ABELIAN Z′ BOSON IN FOUR-FERMION PROCESSES

2001 ◽  
Vol 16 (02) ◽  
pp. 179-188 ◽  
Author(s):  
A. V. GULOV ◽  
V. V. SKALOZUB
Keyword(s):  
Scalar Field ◽  
Z Boson ◽  
Axial Vector ◽  
Scalar Fields ◽  
Low Energy ◽  
Strongly Correlated ◽  
Absolute Value ◽  
Effective Lagrangian ◽  
The Standard Model ◽  
Model Independent

A model independent search for Abelian Z′ gauge boson in four-fermion processes is analyzed. It is based on a low energy effective Lagrangian parametrizing the Z′ interactions with the fermion and scalar fields of the Standard Model. These parameters are related due to the requirement of renormalizability (gauge invariance). It is found that the absolute value of the Z′ coupling to the axial-vector currents is the same for all fermions and it is strongly correlated with the Z′ coupling to the scalar field. On the base of these relations the dependences between the parameters of the effective Lagrangian constructed from dimension-six operators are derived.

scholarly journals STANDARD MODEL HIGGS COMBINED RESULT FROM CDF

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 825-827
Author(s):  
◽  
JOÃO GUIMARÃES DA COSTA
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Z Boson ◽  
Decay Channel ◽  
Vector Boson ◽  
Associated Production ◽  
The Standard Model ◽  
The Individual ◽  
Cross Section Limit

The Tevatron is expected to be most sensitive to the Standard Model Higgs in its associated production with a W or Z boson. The Collider Detector at Fermilab (CDF) has performed individual searches for such production in each decay channel of the vector boson, assuming that the Higgs decays to [Formula: see text]. These searches use data collected by CDF during the 1992-95 run. The individual results are reviewed, and a combined cross section limit is presented.

scholarly journals THE EFFECT OF ELECTROMAGNETIC PROPERTIES OF NEUTRINOS ON THE PHOTON–NEUTRINO DECOUPLING TEMPERATURE

2012 ◽  
Vol 27 (32) ◽  
pp. 1250187
Author(s):  
S. C. İNAN ◽  
M. KÖKSAL
Keyword(s):  
Lagrangian Model ◽  
Electromagnetic Properties ◽  
Beyond The Standard Model ◽  
Ultrahigh Energy ◽  
Qcd Phase Transition ◽  
Effective Lagrangian ◽  
Independent Analysis ◽  
The Standard Model ◽  
Model Independent ◽  
The Impact

We examine the impact of electromagnetic properties of neutrinos on the annihilation of relic neutrinos with ultrahigh energy cosmic neutrinos for the [Formula: see text] process. For this process, photon–neutrino decoupling temperature is calculated via effective Lagrangian model beyond the standard model. We find that photon–neutrino decoupling temperature can be importantly reduced below the QCD phase transition with the model independent analysis defining electromagnetic properties of neutrinos.

H1 INCLUSIVE CROSS-SECTION MEASUREMENTS AND AN EXTRACTION OF PARTON DISTRIBUTION FUNCTIONS

2005 ◽  
Vol 20 (21) ◽  
pp. 1557-1571
Author(s):  
BURKARD REISERT
Keyword(s):  
Cross Section ◽  
Parton Distribution ◽  
Inclusive Cross Section ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Single Experiment ◽  
Parton Distributions ◽  
The Standard Model ◽  
Qcd Analysis

An extraction of the parton distributions of the proton by a next-to-leading order QCD fit in the framework of the Standard Model is presented. The fit implements a novel decomposition of the quark species into up- and down-type quark distributions, which is the key to enable a determination of flavor separated parton distributions from a single experiment. The fit is performed on the inclusive unpolarized neutral and charged current cross-section measurements by the H1 collaboration at HERA. The discussion of uncertainties of parton distribution functions is based upon but extends the QCD analysis published together with the H1 data.

scholarly journals Precision Electroweak Data: Present Status and Future Prospects

1997 ◽  
Vol 12 (23) ◽  
pp. 4109-4154 ◽  
Author(s):  
Peter B. Renton
Keyword(s):  
Standard Model ◽  
Present Status ◽  
Model Parameters ◽  
Second Phase ◽  
Independent Variables ◽  
The Standard Model ◽  
Model Independent ◽  
The Impact ◽  
Precision Electroweak Data

The present status of precision electroweak data is reviewed. These data include LEP measurements of the mass and width of the Z, together with various measurements on the Z-fermion couplings. These data are compared to, and combined with, data from the SLC on the left–right polarized asymmetry, A LR , and the left–right forward–backward asymmetries for b and c quarks. These measurements are combined with hadron collider measurements from the Tevatron and CERN on the mass of the W boson, mW, as well as other electroweak data, in global electroweak fits in which various Standard Model parameters are determined. A comparison is made between the results of direct measurements of mW and the top-quark mass, mt, as determined from the Tevatron, with the indirect results coming from electroweak radiative corrections. Using all precision electroweak data, fits are also made to determine limits on the mass of the Higgs boson, mH. The influence on these limits of specific measurements, particularly those which are somewhat inconsistent with the Standard Model, is explored. The data are also analyzed in terms of the quasi model independent ∊ variables. Improvements in the determination of all of these quantities are expected when the Z data at LEP are fully analyzed, and further measurements on A LR and related asymmetries performed at the SLC. In addition, substantial improvements in the determination of mW are expected from measurements at the Tevatron and in the second phase of LEP. An estimate is made of the likely precision of these data, and the implications of the impact of these data on precision electroweak tests are discussed. This discussion is made both in terms of the Standard Model and also in the context of the quasi model independent ∊ variables.

scholarly journals EXPERIMENTAL TESTS ON THE LIFETIME ASYMMETRY

2011 ◽  
Vol 26 (13) ◽  
pp. 987-998 ◽  
Author(s):  
ZHI-QIANG SHI ◽  
GUANG-JIONG NI
Keyword(s):  
Cross Section ◽  
Z Boson ◽  
Particle Physics ◽  
Test Problem ◽  
Precise Measurement ◽  
Experimental Tests ◽  
Moller Scattering ◽  
The Standard Model ◽  
Integrated Cross Section ◽  
Important Significance

The experimental test problem of the left–right polarization-dependent lifetime asymmetry is discussed. It shows that the existing experiments cannot demonstrate the lifetime asymmetry to be right or wrong after analyzing the measurements on the neutron, the muon and the tau lifetime, as well as the g-2 experiment. However, it is pointed out emphatically that the SLD and the E158 experiments, the measurements of the left–right integrated cross section asymmetry in Z boson production by e+e- collisions and by electron–electron Møller scattering, can indirectly demonstrate the lifetime asymmetry. In order to directly demonstrate the lifetime asymmetry, we propose some possible experiments on the decays of polarized muons. The precise measurement of the lifetime asymmetry could have important significance for building a muon collider, also in cosmology and astrophysics. It would provide a sensitive test of the standard model in particle physics and allow for exploration of the possible V+A interactions.

scholarly journals From Hadronic Cross Section to the measurement of the Vacuum Polarization at KLOE: a fascinating endeavour

2018 ◽  
Vol 166 ◽  
pp. 00021 ◽  
Author(s):  
Graziano Venanzoni
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Vacuum Polarization ◽  
Direct Determination ◽  
Initial State Radiation ◽  
Initial State ◽  
Hadronic Cross Section ◽  
State Radiation ◽  
The Standard Model

The KLOE experiment at the ϕ-factory DAΦNE in Frascati is the first to have employed Initial State Radiation (ISR) to precisely determine the e+e− → π+π−(γ) cross section below 1 GeV. Such a measurement is particularly important to test the Standard Model (SM) calculation for the (g – 2) of the muon, where a long standing 3σ discrepancy is observed. I will review the ISR activity in KLOE in the last 20 years from the measurement of the hadronic cross section to the first direct determination of the time-like complex running α(s) in the region below 1 GeV.

scholarly journals PRELIMINARY MEASUREMENTS OF THE QUARK-ANTIQUARK PRODUCTION CROSS-SECTION IN E+E- ANNIHILATIONS UP TO LEP2 HIGHEST ENERGIES

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 342-344
Author(s):  
GIUSEPPE DELLA RICCA
Keyword(s):  
Standard Model ◽  
Pair Production ◽  
Cross Section ◽  
Cross Sections ◽  
Production Cross Section ◽  
Production Cross ◽  
Delphi Detector ◽  
The Standard Model ◽  
Model Predictions ◽  
The Cross

Data collected with the DELPHI detector at [Formula: see text] up to LEP2 highest energies (i.e. exceeding 205 GeV) have been used to extract preliminary values of the cross-sections for quark-antiquark pair-production in e + e - annihilations. The values found were used to test the Standard Model predictions and to seek for physics beyond it.

Drell-Yan Production at the Fermilab Tevatron

2005 ◽  
Vol 20 (15) ◽  
pp. 3236-3239
Author(s):  
◽  
JEDONG LEE
Keyword(s):  
Standard Model ◽  
Differential Cross Section ◽  
Invariant Mass ◽  
Cross Section ◽  
Differential Cross ◽  
Charge Asymmetry ◽  
New Physics ◽  
The Standard Model ◽  
Model Predictions ◽  
Using Data

Using data from [Formula: see text] collisions at [Formula: see text] collected by the CDF and DØ detectors, we present measurements of the Drell-Yan inclusive differential cross section and forward-backward charge asymmetry as a function of invariant mass. We compare these measurements with Standard Model predictions, and present searches for new physics that could appear as deviations from the Standard Model in the Drell-Yan differential cross section.

NEW NEUTRAL GAUGE BOSONS AT HIGH ENERGY e+e− COLLIDERS

1989 ◽  
Vol 04 (17) ◽  
pp. 4551-4565 ◽  
Author(s):  
JOANNE L. HEWETT ◽  
THOMAS G. RIZZO
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Z Bosons ◽  
High Energy ◽  
Beam Polarization ◽  
Gauge Bosons ◽  
Final State ◽  
The Standard Model ◽  
Model Predictions ◽  
Coupling Parameters

We discuss and contrast search limits for and properties of new Z′ gauge bosons which can be probed at high energy e+e− colliders within the context of several E6 superstring-inspired models. In particular, we discuss the probability of distinguishing these various models from one another and determining the Z′ coupling parameters uniquely. Using the deviations from the standard model predictions for asymmetries and cross sections for various final state fermions, we set discovery limits for new Z′ bosons at [Formula: see text] and 1 TeV e+e− colliders. We find quite generally that cross section deviations provide the strongest limits on the existence of new Z′ bosons below threshold even when 100% beam polarization is available. The possibility of using Z′ pair production as a sensitive probe of the e+e−Z′ coupling is also examined.

Sign in / Sign up

Export Citation Format

Share Document