3,325 Matching Results

Search Results

Advanced search parameters have been applied.

Z' Bosons, the NuTeV Anomaly, and the Higgs Boson Mass

Description: Fits to the precision electroweak data that include the NuTeV measurement are considered in family universal, anomaly free U(1) extensions of the Standard Model. In data sets from which the hadronic asymmetries are excluded, some of the Z{prime} models can double the predicted value of the Higgs boson mass, from {approx} 60 to {approx} 120 GeV, removing the tension with the LEP II lower bound, while also modestly improving the {chi}{sup 2} confidence level. The effect of the Z{prime} models on both m{sub H} and the {chi}{sup 2} confidence level is increased when the NuTeV measurement is included in the fit. Both the original NuTeV data and a revised estimate by the PDG are considered.
Date: March 3, 2009
Creator: Chanowitz, Michael S
Partner: UNT Libraries Government Documents Department

Anti-B-B Mixing Constrains Topcolor-Assisted Technicolor

Description: We argue that extended technicolor augmented with topcolor requires that all mixing between the third and the first two quark generations resides in the mixing matrix of left-handed down quarks. Then, the anti-B_d--B_d mixing that occurs in topcolor models constrains the coloron and Z' boson masses to be greater than about 5 TeV. This implies fine tuning of the topcolor couplings to better than 1percent.
Date: December 6, 2000
Creator: Burdman, Gustavo; Lane, Kenneth & Rador, Tonguc
Partner: UNT Libraries Government Documents Department

Report of the subgroup on alternative models and new ideas

Description: We summarize some of the work done by the P3 subgroup on Alternative Models and New Ideas. The working group covered a broad range of topics including a constrained Standard Model from an extra dimension, a discussion of recent ideas addressing the strong CP problem, searches for doubly charged higgs bosons in e{gamma} collisions, and an update on discovery limits for extra neutral gauge bosons at hadron colliders. The breadth of topics rejects the many ideas and approaches to physics beyond the Standard Model.
Date: November 19, 2002
Creator: Chertok, M.; Dienes, K.; Godfrey, S.; Kalyniak, P.; Kaplan, D.; Kribs, G. D. et al.
Partner: UNT Libraries Government Documents Department

Top quark physics: Overview

Description: In this presentation I will primarily focus on top quark physics but I will include a discussion of the W-boson mass and the possibility of discovering a light Higgs boson via associated production at the Tevatron.
Date: January 1, 1998
Creator: Parke, S.
Partner: UNT Libraries Government Documents Department

A new measurement of the W boson mass at D-Zero

Description: We present a new measurement of the W mass using the W {yields} e{nu} data from the D0 forward detectors at the Fermilab Tevatron p{anti p} Collider. This is the first measurement of the W mass with electron candidates in the range 1.5 <| {eta} |< 2.5. We present measurements of the W mass using the transverse mass, the electron transverse momentum and the neutrino transverse momen- tum, and the combined result using all three techniques. The combination of the forward detector measurement with the previous measurements using the central detector gives a new precise measurement of the W mass from D0.
Date: July 26, 1999
Creator: al., B. Abbott et
Partner: UNT Libraries Government Documents Department

Structure functions of electroweak boson and leptons

Description: The QCD structure of the electroweak bosons is reviewed and the lepton structure function is defined and calculated. The leading order splitting functions of electron into quarks are extracted, showing an important contribution from {gamma}-Z interference. Leading logarithmic QCD evolution equations are constructed and solved in the asymptotic region where log{sup 2} behavior of the Parton densities is observed. Possible applications with clear manifestation of ``resolved`` photon and weak bosons are discussed. 8 refs., 3 figs.
Date: April 2, 1996
Creator: Slominski, W & Szwed, J.
Partner: UNT Libraries Government Documents Department

WW and WZ production at the tevatron

Description: Direct limits are set on WWZ and WW{gamma} three-boson couplings in a search for WW and WZ production in p{bar p} collisions at {radical}s = 1.8 TeV using the D(0) and CDF detectors at the Fermilab Tevatron.
Date: April 1, 1995
Creator: Fuess, T.A.
Partner: UNT Libraries Government Documents Department

Precision tests of quantum chromodynamics and the standard model

Description: The authors discuss three topics relevant to testing the Standard Model to high precision: commensurate scale relations, which relate observables to each other in perturbation theory without renormalization scale or scheme ambiguity, the relationship of compositeness to anomalous moments, and new methods for measuring the anomalous magnetic and quadrupole moments of the W and Z.
Date: June 1, 1995
Creator: Brodsky, S. J. & Lu, H. J.
Partner: UNT Libraries Government Documents Department

Will at least one of the Higgs bosons of the next-to-minimal supersymmetric extension of the standard model be observable at LEP2 or the LHC?

Description: We demonstrate that there are regions of parameter space in the next-to-minimal (i.e. two-Higgs-doublet, one-Higgs-singlet superfield) supersymmetric extension of the SM for which none of the Higgs bosons are observable either at LEP2 with $\sqrt{s}=192 GeV$ and an integrated luminosity of $L=1000inverse pb$ or at the LHC with $L=600 inverse fb$.
Date: June 24, 1996
Creator: Gunion, John F.; Haber, Howard E. & Moroi, Takeo
Partner: UNT Libraries Government Documents Department

Higgs Mass Constraints on a Fourth Family: Upper and Lower Limits on CKM Mixing

Description: Theoretical and experimental limits on the Higgs boson mass restrict CKM mixing of a possible fourth family beyond the constraints previously obtained from precision electroweak data alone. Existing experimental and theoretical bounds on m{sub H} already significantly restrict the allowed parameter space. Zero CKM mixing is excluded and mixing of order {theta}{sub Cabbibo} is allowed. Upper and lower limits on 3-4 CKM mixing are exhibited as a function of m{sub H}. We use the default inputs of the Electroweak Working Group and also explore the sensitivity of both the three and four family fits to alternative inputs.
Date: June 25, 2010
Creator: Chanowitz, Michael S.
Partner: UNT Libraries Government Documents Department

Double boson production at CDF

Description: New measurements of boson pair production in {ital p}{ital {anti p}} collisions have been performed by the CDF collaboration using a data sample of approximately 110 pb{sup -1}. The cross sections for WW and WZ production are measured in the pure leptonic decay channel to {sigma}({ital p}{ital {anti p}} {r_arrow} WZ) = 3.2{sup +5.0}{sub -3. 2} pb and {sigma}({ital p}{ital {anti p}} {r_arrow} W{sup +}W{sup -}) = 10.2{sup +6.5}{sub -5.3} pb, respectively. Limits on anomalous coupling parameters are set in the searches for WW and WZ production. Assuming an energy scale of {Lambda}{sub FF} = 2 TeV, we find for the WWZ and WW{gamma} couplings at 95% CL: -0.4 {lt} {lambda} {lt} 0.3 ({delta}{kappa} = 0) and -0.5 {lt} {delta}{kappa} {lt} 0.5 ({lambda} = 0).
Date: July 1, 1996
Creator: Neuberger, D.
Partner: UNT Libraries Government Documents Department

W and Z boson plus jets production at CDF

Description: We have studied the production properties of {ital W} and {ital Z} bosons at CDF, and have measured the jet multiplicity cross sections and various kinematic distributions. We find good agreement with leading order QCD predictions with added gluon radiation and simulated parton fragmentation.
Date: September 1, 1996
Creator: Phillips, T. J.
Partner: UNT Libraries Government Documents Department

Diboson production at the Tevatron

Description: The CDF and D{null} detectors at the Tevatron Collider are being used to measure {ital WW}, {ital WZ}, and {ital ZZ} production as well as {ital W}{sub {gamma}} and {ital Z}{sub {gamma}} production in order to study Trilinear Gauge Couplings. Improved limits on nonstandard coupling parameters are given and prospects for further improvement are discussed.
Date: September 1, 1996
Creator: Nodulman, L.J. & Collaborations, CDF and D0
Partner: UNT Libraries Government Documents Department

W Boson physics at the Fermilab Tevatron Collider

Description: Recent results from the CDF and D0 Experiments at the Fermilab Tevatron Collider are presented for the W and Z boson production cross sections, the W boson width, rare W boson decays, trilinear gauge boson couplings, and the W boson mass.
Date: August 1, 1998
Creator: Madaras, Ronald J.
Partner: UNT Libraries Government Documents Department

Boson pair production and triple gauge couplings

Description: The D0 and CDF Collaborations measure boson pair production including W{gamma}, WW, WZ, ZZ and Z{gamma} production in p{anti p} collisions at {radical}s = 1800 GeV. New results, from direct measurements, are described including W{gamma}, WW, and Z{gamma} production cross sections and limits on non-Standard Model triple gauge boson couplings. The limits on anomalous WW{gamma}, WWZ, Z{gamma}{gamma} and ZZ{gamma} couplings are the most restrictive available. Prospects for Run II are discussed.
Date: June 1, 1997
Creator: Diehl, H.T. & Collaborations, D0 and CDF
Partner: UNT Libraries Government Documents Department

Top and higgs at the Tevatron: Measurements, searches, prospects

Description: In this paper we summarize the status of Top Quark Physics and of searches for the Standard Model Higgs at the Tevatron. Results from both the CDF and D0 experiments are discussed and the prospects for the upcoming Run 2, in the year 2000, are outlined. Much work has been performed on these topics and due to the nature of these proceedings only a brief explanation can be offered here. For more details the reader should turn to the excellent sources listed in the reference section.
Date: May 11, 1999
Creator: Konigsberg, J.
Partner: UNT Libraries Government Documents Department

First Run II Measurement of the W Boson Mass

Description: We describe a measurement of the W boson mass m{sub W} using 200 pb{sup -1} of {radical}s = 1.96 TeV p{bar p} collision data taken with the CDF II detector. With a sample of 63,964 W {yields} e{nu} candidates and 51,128 W {yields} {mu}{nu} candidates, we measure m{sub W} = [80.413 {+-} 0.034(stat.) {+-} 0.034 (sys.) = 80.413 {+-} 0.048] GeV/c{sup 2}. This is the single most precise m{sub W} measurement to date. When combined with other measured electroweak parameters, this result further constrains the properties of new unobserved particles coupling to W and Z bosons.
Date: August 1, 2007
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Abulencia, A.; /Illinois U., Urbana; Adelman, J.; /Chicago U., EFI et al.
Partner: UNT Libraries Government Documents Department

Measurements of the Trilinear Gauge Boson Couplings from Diboson Production at D0

Description: The most recent measurements of the trilinear gauge boson couplings from the diboson production at the D0 experiment has been presented. The analyzed final states are Z{gamma} {yields} {nu}{nu}{gamma}, WW {yields} l{nu}l{prime}{nu}, and WW+WZ {yields} l{nu}jj. We also present results obtained combining all final states involving the W boson. These results represent the most stringent limits set to date at the hadron collider.
Date: October 1, 2009
Creator: Sekaric, Jadranka
Partner: UNT Libraries Government Documents Department

Standard Model Bosons as Composite Particles

Description: The Standard model of electro-weak interactions is derived from a Nambu, Jona-Lasinio type four-fermion interaction, which is assumed to result from a more basic theory valid above a very high scale lamba.The masses of the gauge bosons and the Higgs are then produced by dynamical symmetry breaking of the Nambu model at an intermediate scale mu, and are evolved back to experimental energies via the renormalisation group equations of the Standard model.The weak angle sin^2(Theta(sub)W) is predicted to be 3/8 at the scale mu, as in grand unified theories, and is evolved back to the experimental value at scale M(sub)W, thus determining mu ~ 10^13 GeV.Predictions for the ratios of the masses of the gauge and the Higgs bosons to the top quark mass, at experimental energies, are also obtained.
Date: April 1, 1991
Creator: Kahana, David & Kahana, David
Partner: UNT Libraries Government Documents Department

Search for supersymmetric charged Higgs bosons at the TeVatron

Description: The data collected at the TeVatron RunIIa have been used to look for supersymmetric charged Higgs boson and Left-Right suspersymmetric doubly charged Higgs boson. No signal of such bosons has been found and this note reports on the current analyses and their observed excluded domains in models parameter space.
Date: October 1, 2007
Creator: Grenier, Gerald & /Lyon, IPN
Partner: UNT Libraries Government Documents Department

Ratio method of measuring $w$ boson mass

Description: This dissertation describes an alternative method of measuring the W boson mass in D0 experiment. Instead of extracting M{sub W} from the fitting of W {yields} e{nu} fast Monte Carlo simulations to W {yields} e{nu} data as in the standard method, we make the direct fit of transverse mass between W {yields} e{nu} data and Z {yields} ee data. One of the two electrons from Z boson is treated as a neutrino in the calculation of transverse mass. In ratio method, the best fitted scale factor corresponds to the ratio of W and Z boson mass (M{sub W}/M{sub Z}). Given the precisely measured Z boson mass, W mass is directly fitted from W {yields} e{nu} and Z {yields} ee data. This dissertation demonstrates that ratio method is a plausible method of measuring the W boson mass. With the 1 fb{sup -1} D0 Run IIa dataset, ratio method gives M{sub W} = 80435 {+-} 43(stat) {+-} 26(sys) MeV.
Date: August 1, 2010
Creator: Guo, Feng & /SUNY, Stony Brook
Partner: UNT Libraries Government Documents Department