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Implications for supersymmetry of the CERN monojets

Description: Results of a comprehensive study of supersymmetric processes which could give monojet events similar to those observed at the CERN Sp anti pS are presented. If supersymmetry is to be the explanation of the monojets, strict bounds are obtained on possible supersymmetric masses. 15 references.
Date: January 1, 1985
Creator: Haber, H.E.
Partner: UNT Libraries Government Documents Department

Signals of new W's and Z's

Description: If new heavy charged and/or neutral gauge bosons exist with masses below 5 to 10 TeV, they can be observed at the SSC. In this report, we summarize the work of the New W/Z Physics Subgroup. The expected properties of new heavy gauge bosons (such as new W's and Z's or horizontal gauge bosons) are summarized. We then discuss various signatures of these new gauge bosons and their implications for detector designers. Suggestions for future work are indicated. 60 references.
Date: September 1, 1984
Creator: Haber, H.E.
Partner: UNT Libraries Government Documents Department

Taus: a probe of new W and Z couplings

Description: If new heavier W's and/or Z's are discovered at the SSC, only partial information on their couplings to quarks and leptons can be obtained by studying their decays into electrons and muons. In particular, without polarized beams, one cannot distinguish between heavy W's which have left-handed (W/sub L/) or right-handed (W/sub R/) couplings to all fermions. Here, we study the tau decays of W/sub L/ and W/sub R/ and compute the distributions of the tau decay products. The most striking effect is W ..-->.. tau + N followed by tau ..-->.. ..pi.. nu/sub tau/; the pT distribution of the pion can distinguish W/sub L/ from W/sub R/ (without a measurement of the pion electric charge).
Date: August 1, 1984
Creator: Haber, H.E.
Partner: UNT Libraries Government Documents Department

What if the Higgsino is the lightest supersymmetric particles

Description: A pedagogical introduction to the mixing of neutral gauginos and Higgsinos in supersymmetric models is given. The possibility that the Higgsino (rather than the photino) is the lightest supersymmetric particle is considered and implications for phenomenology are discussed with some emphasis on signatures of supersymmetry in Z decays. Some related aspects of Higgs boson detection in Z decays are mentioned.
Date: November 1, 1985
Creator: Haber, H.E.
Partner: UNT Libraries Government Documents Department

A primer on Higgs boson low-energy theorems

Description: We give a pedagogical review of Higgs boson low-energy theorems and their applications in the study of light Higgs boson interactions with mesons and baryons. In particular, it is shown how to combine the chiral Lagrangian method with the Higgs low-energy theorems to obtain predictions for the interaction of Higgs bosons and pseudoscalar mesons. Finally, we discuss the relation between the low-energy theorems and a technique which makes use of the trace of the QCD energy-momentum tensor. 35 refs.
Date: May 1, 1989
Creator: Dawson, S. & Haber, H.E.
Partner: UNT Libraries Government Documents Department

Simulating supersymmetry at the SSC

Description: Careful study of supersymmetric signatures at the SSC is required in order to distinguish them from Standard Model physics backgrounds. To this end, we have created an efficient, accurate computer program which simulates supersymmetric particle production and decay (or other new particles). We have incorporated the full matrix elements, keeping track of the polarizations of all intermediate states. (At this time hadronization of final-state partons is ignored). Using Monte Carlo techniques this program can generate any desired final-state distribution or individual events for Lego plots. Examples of the results of our study of supersymmetry at SSC are provided.
Date: August 1, 1984
Creator: Barnett, R.M. & Haber, H.E.
Partner: UNT Libraries Government Documents Department

Heavy particle production at the SSC

Description: Predictions for the production of heavy quarks, supersymmetric particles, and other colored systems at high energy due to intrinsic twist-six components in the proton wavefunction are given. We also suggest the possibility of using asymmetric collision energies (e.g., via intersecting rings at the SSC) in order to facilitate the study of forward and diffractive particle production processes. 9 references.
Date: March 1, 1984
Creator: Brodsky, S.J.; Haber, H.E. & Gunion, J.F.
Partner: UNT Libraries Government Documents Department

Higgs boson hunting

Description: This is the summary report of the Higgs Boson Working Group. We discuss a variety of search techniques for a Higgs boson which is lighter than the Z. The processes K /yields/ /pi/H, /eta//prime/ /yields/ /eta/H,/Upsilon/ /yields/ H/gamma/ and e/sup +/e/sup /minus// /yields/ ZH are examined with particular attention paid to theoretical uncertainties in the calculations. We also briefly examine new features of Higgs phenomenology in a model which contains Higgs triplets as well as the usual doublet of scalar fields. 33 refs., 6 figs., 1 tab.
Date: May 1, 1989
Creator: Dawson, S.; Haber, H.E. & Rindani, S.D.
Partner: UNT Libraries Government Documents Department


Description: We have eomputed the first non-trivial QCD corrections to the quark-quark scattering process which contributes to the production of hadrons at large p{sub T} in hadron-hadron collisions. Using quark distribution functions defined in deep inelastic scattering and fragmentation functions defined in one particle inclusive e{sup +}e{sup -} annihilation, we find that the corrections are large. This implies that QCD perturbation theory may not be reliable for large p{sub T} hadron physics.
Date: December 1, 1979
Creator: Ellis, R.K.; Furman, M.A.; Haber, H.E. & Hinchliffe, I.
Partner: UNT Libraries Government Documents Department

Probing the non-minimal Higgs sector at the SSC

Description: Non-minimal Higgs sectors occur in the Standard Model with more than one Higgs doublet, as well as in theories that go beyond the Standard Model. In this report, we discuss how Higgs search strategies must be altered, with respect to the Standard Model approaches, in order to probe the non-minimal Higgs sectors at the SSC.
Date: November 1, 1987
Creator: Gunion, J.F.; Haber, H.E.; Komamiya, S.; Yamamoto, H. & Barbaro-Galtieri, A.
Partner: UNT Libraries Government Documents Department

Electro symmetry breaking and beyond the standard model

Description: The development of the Standard Model of particle physics is a remarkable success story. Its many facets have been tested at present day accelerators; no significant unambiguous deviations have yet been found. In some cases, the model has been verified at an accuracy of better than one part in a thousand. This state of affairs presents our field with a challenge. Where do we go from here? What is our vision for future developments in particle physics? Are particle physicists` recent successes a signal of the field`s impending demise, or do real long-term prospects exist for further progress? We assert that the long-term health and intellectual vitality of particle physics depends crucially on the development of a new generation of particle colliders that push the energy frontier by an order of magnitude beyond present capabilities. In this report, we address the scientific issues underlying this assertion.
Date: May 1, 1995
Creator: Barklow, T.; Dawson, S.; Haber, H.E. & Siegrist, J.
Partner: UNT Libraries Government Documents Department

Search for horizontal bosons at the SSC

Description: The production process anti p p ..-->.. l/sup -/l'/sup +/ + X, where the leptons belong to two different generations and X refers to spectator jets, provides a clear signature for horizontal (generation-changing) bosons when the leptons are emitted nearly back-to-back and p/sub T//sup miss/ = 0. Cross sections and p/sub T/ distributions for each lepton are presented, and discovery limits on M/sub H/ are extracted for several different channels.
Date: January 1, 1984
Creator: Albright, C.H.; Deshpande, N.G.; Gunion, J.F. & Haber, H.E.
Partner: UNT Libraries Government Documents Department


Description: In this summary report of the 2001 Snowmass Electroweak Symmetry Breaking Working Group, the main candidates for theories of electroweak symmetry breaking are surveyed, and the criteria for distinguishing among the different approaches are discussed. The potential for observing electroweak symmetry breaking phenomena at the upgraded Tevatron and the LHC is described. We emphasize the importance of a high-luminosity e{sup +}e{sup -} linear collider for precision measurements to clarify the underlying electroweak symmetry breaking dynamics. Finally, we note the possible roles of the {mu}{sup +} {mu}{sup -} collider and VLHC for further elucidating the physics of electroweak symmetry breaking.
Date: June 30, 2001
Partner: UNT Libraries Government Documents Department

Opportunities and requirements for experimentation at high energy e/sup +/e/sup /minus// collider

Description: Over the past fifteen years of high-energy physics, electron-positron annihilation has been the most productive of all reactions probing the fundamental interactions. The e/sup +/e/sup /minus// annihilation process is unique in offering at the same time copious production of novel particles, low backgrounds from more conventional physics, and the most efficient use of the energy which an accelerator provides. These features have allowed the detailed characterization of the charm and bottom quark-antiquark systems and the unambiguous discovery of gluon jets---the crucial ingredients in the establishment of Quantum Chromodynamics as the correct theory of the strong interactions---as well as the discovery of the tau lepton and confirmation of the weak and electromagnetic properties of all the quarks and leptons at high energy. Over the past few years, experiments will begin at SLC and LEP, and we anticipate new discoveries from the detailed study of the Z/sup 0/ resonance. It is time, then to begin to think out how one might continue this mode experimentation to still higher energies. This document is the report of a committee convened by the Director of SLAC, Burton Richter, to set out the major physics goals of an e/sup +/e/sup /minus// collider in the energy range 600 GeV-1 TeV, corresponding to the next feasible step in accelerator technology. The committee was charged with the task of outlining the main experiments that such a collider might carry out and the requirements which those experiments place on the accelerator design. 106 refs., 105 figs., 13 tabs.
Date: May 1, 1988
Creator: Ahn, C.; Baltay, C.; Barklow, T.L.; Burchat, P.R.; Burke, D.L.; Cooper, A.R. et al.
Partner: UNT Libraries Government Documents Department

Techniques for finding supersymmetry at the SSC

Description: We examine the signatures at the SSC for supersymmetry for much of the (minimal) supersymmetric model parameter space. In particular, we survey the decay modes and signatures of gluinos and squarks. Gluinos (squarks) decay to two (one) jets and a chargino or neutralino (chi-tilde). This chi-tilde may be the (stable) lightest supersymmetric particle, LSP (and lead to missing energy). Or chi-tilde may have a two-body decay to another chi-tilde plus a W, Z or Higgs boson. Finally, it may have a three-body decay to the LSP plus q anti q, e nu, ..mu..nu, ee or ..mu mu... Only for very light gluinos and squarks is the decay mode containing the LSP dominant. In fact, for gluinos and squarks over 500 GeV, the decays to W and Z bosons dominate for much of parameter space. We estimate the backgrounds for the case in which both gluinos decay to Z bosons. The decays of gluinos and squarks which go directly to the LSP lead to very large missing energy. We report the initial results of a study of the backgrounds for this process. 22 refs., 11 figs., 3 tabs.
Date: October 1, 1987
Creator: Barnett, R.M.; Klopfenstein, C.; Wang, E.; Pauss, F.; Gunion, J.F.; Haber, H.E. et al.
Partner: UNT Libraries Government Documents Department

Testing the viability of the E/sub T//sup miss/ signature in gluino production at the SSC

Description: We report on a preliminary study at SSC energies of signatures and backgrounds for heavy gluinos in the minimal supersymmetric extension of the Standard Model. Unlike previous studies we account for the small branching ratio of gluinos to the lightest supersymmetric particle. We find that an E/sub T//sup miss/ signature is observable over the Standard Model background.
Date: January 1, 1988
Creator: Barnett, R.M.; Freeman, J.; Raja, R.; Gunion, J.F.; Haber, H.E.; Hollebeek, R. et al.
Partner: UNT Libraries Government Documents Department

Report of the Tevatron Higgs working group.

Description: Despite the success of the Standard Model (SM), which provides a superb description of a wide range of experimental particle physics data, the dynamics responsible for electroweak symmetry breaking is still unknown. Its elucidation remains one of the primary goals of future high energy physics experimentation. Present day global fits to precision electroweak data based on the Standard Model favor the existence of a weakly-interacting scalar Higgs boson, which is a remnant of elementary scalar dynamics that drives electroweak symmetry breaking. The only known viable theoretical framework incorporating light elementary scalar fields employs low-energy supersymmetry, where the scale of supersymmetry breaking is {Omicron} (1 TeV). The Higgs sector of the Minimal Supersymmetric extension of the Standard Model (MSSM) is of particular interest because it predicts the existence of a light CP-even neutral Higgs boson with a mass below about 130 GeV. Moreover, over a significant portion of the MSSM parameter space, the properties of this scalar are indistinguishable from those of the SM Higgs boson.
Date: November 14, 2000
Creator: Carena, M.; Conway, J. S.; Haber, H. E.; Hobbs, J. D.; Harris, B. W.; Kuhlmann, S. et al.
Partner: UNT Libraries Government Documents Department

Searching for top decays to charged Higgs bosons with the SDC detector

Description: We have studied the capabilities of the SDC detector to discover a charged Higgs boson in the decay t {yields} H{sup +}b for the particular case m{sub t} = 250 GeV/c{sup 2} and m{sub H}{sup {plus minus}} = 150 GeV/c{sup 2}. The two methods investigated both tag t{anti t} events by demanding a high-p{sub t} lepton and two identified b-quark jets. In the first technique we search for an excess of {tau} leptons from H{sup {plus minus}} decays; in the second, we look for a peak in the two-jet mass distribution resulting from H{sup +} {yields} c{anti s}. In combination, these two techniques allow discovery of such a charged Higgs boson over the entire interesting range of two-Higgs-doublet model parameter space. 8 refs., 11 figs., 2 tabs.
Date: November 1, 1990
Creator: Barnett, R.M.; Hinchliffe, I. (Lawrence Berkeley Lab., CA (USA)); Gunion, J.F. (California Univ., Davis, CA (USA)); Haber, H.E.; Hubbard, B. (California Univ., Santa Cruz, CA (USA)) & Trost, H.J. (Argonne National Lab., IL (USA))
Partner: UNT Libraries Government Documents Department

The Case for a 500 GeV e+e- Linear Collider

Description: Several proposals are being developed around the world for an e+e- linear collider with an initial center of mass energy of 500 GeV. In this paper, we will discuss why a project of this type deserves priority as the next major initiative in high energy physics.
Date: July 5, 2000
Creator: Baggers, J.; Baltay, C.; Barker, T.; Barklow, T.; Bauer, U.; Bolton, T. et al.
Partner: UNT Libraries Government Documents Department