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Title: Study of SUSY signatures at the Fermilab Tevatron in models with near mass degeneracy of the lightest chargino and neutralino

Abstract

For some choices of soft supersymmetry (SUSY)-breaking parameters, the lightest supersymmetric particle (LSP) is a stable neutralino {chi}(tilde sign){sub 1}{sup 0}, the NLSP is a chargino {chi}(tilde sign){sub 1}{sup {+-} almost degenerate in mass with the LSP ({delta}m{sub {chi}}{sub (tilde sign)1}}{identical_to}m{sub {chi}}{sub (tilde sign)1}{+-}-m{sub {chi}}{sub (tilde sign){sub 1}{sup 0}}{approx}m{sub {pi}}-few GeV), and all other sparticles are relatively heavy. In this case, detection of sparticles in the usual, supergravity (MSUGRA)-motivated signals will be difficult, since the decay products in {chi}(tilde sign){sub 1}{sup {+-}}{yields}{chi}(tilde sign){sub 1}{sup 0}... will be very soft, and alternative signals must be considered. Here, we study the viability of signatures at the Fermilab Tevatron based on highly ionizing charged tracks, disappearing charged tracks, large impact parameters, missing transverse energy, and a jet or a photon, and determine the mass reach of such signatures assuming that only the {chi}(tilde sign){sub 1}{sup {+-}} and {chi}(tilde sign){sub 1}{sup 0} are light. We also consider the jet+Ee{sub T} and {gamma}+Ee{sub T} signatures assuming that the gluino is also light with m{sub g(tilde sign)}{approx}m{sub {chi}}{sub (tilde sign)1{sup {+-}}}. We find that the mass reach is critically dependent upon {delta}m{sub {chi}}{sub (tilde sign){sub 1}} and m{sub g(tilde sign)}-m{sub {chi}}{sub (tilde sign){sub 1{sup {+-}}. Ifmore » {delta}m{sub {chi}}{sub (tilde sign){sub 1}} is sufficiently big that c{tau}({chi}(tilde sign){sub 1}{sup {+-}})(less-or-similar sign)few cm and m{sub g(tilde sign)} is large, there is a significant possibility that the limits on m{sub {chi}}{sub (tilde sign){sub 1}}{sup {+-}}} based on CERN LEP2 data cannot be extended at the Fermilab Tevatron. If c{tau}({chi}(tilde sign){sub 1}{sup {+-}})>few cm, relatively background-free signals exist that will give a clear signal of {chi}(tilde sign){sub 1}{sup {+-}} production (for some range of m{sub {chi}}{sub (tilde sign)1{sup {+-}}}) even if m{sub g(tilde sign)} is very large. (c) 2000 The American Physical Society.« less

Authors:
 [1];  [1]
  1. Davis Institute for High Energy Physics, University of California, Davis, California 95616 (United States)
Publication Date:
OSTI Identifier:
20216972
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 62; Journal Issue: 1; Other Information: PBD: 1 Jul 2000; Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; SUPERSYMMETRY; FERMILAB TEVATRON; SPARTICLES; SUPERGRAVITY; JET MODEL; MASS; EXPERIMENTAL DATA; THEORETICAL DATA

Citation Formats

Gunion, John F, and Mrenna, Stephen. Study of SUSY signatures at the Fermilab Tevatron in models with near mass degeneracy of the lightest chargino and neutralino. United States: N. p., 2000. Web. doi:10.1103/PhysRevD.62.015002.
Gunion, John F, & Mrenna, Stephen. Study of SUSY signatures at the Fermilab Tevatron in models with near mass degeneracy of the lightest chargino and neutralino. United States. https://doi.org/10.1103/PhysRevD.62.015002
Gunion, John F, and Mrenna, Stephen. 2000. "Study of SUSY signatures at the Fermilab Tevatron in models with near mass degeneracy of the lightest chargino and neutralino". United States. https://doi.org/10.1103/PhysRevD.62.015002.
@article{osti_20216972,
title = {Study of SUSY signatures at the Fermilab Tevatron in models with near mass degeneracy of the lightest chargino and neutralino},
author = {Gunion, John F and Mrenna, Stephen},
abstractNote = {For some choices of soft supersymmetry (SUSY)-breaking parameters, the lightest supersymmetric particle (LSP) is a stable neutralino {chi}(tilde sign){sub 1}{sup 0}, the NLSP is a chargino {chi}(tilde sign){sub 1}{sup {+-} almost degenerate in mass with the LSP ({delta}m{sub {chi}}{sub (tilde sign)1}}{identical_to}m{sub {chi}}{sub (tilde sign)1}{+-}-m{sub {chi}}{sub (tilde sign){sub 1}{sup 0}}{approx}m{sub {pi}}-few GeV), and all other sparticles are relatively heavy. In this case, detection of sparticles in the usual, supergravity (MSUGRA)-motivated signals will be difficult, since the decay products in {chi}(tilde sign){sub 1}{sup {+-}}{yields}{chi}(tilde sign){sub 1}{sup 0}... will be very soft, and alternative signals must be considered. Here, we study the viability of signatures at the Fermilab Tevatron based on highly ionizing charged tracks, disappearing charged tracks, large impact parameters, missing transverse energy, and a jet or a photon, and determine the mass reach of such signatures assuming that only the {chi}(tilde sign){sub 1}{sup {+-}} and {chi}(tilde sign){sub 1}{sup 0} are light. We also consider the jet+Ee{sub T} and {gamma}+Ee{sub T} signatures assuming that the gluino is also light with m{sub g(tilde sign)}{approx}m{sub {chi}}{sub (tilde sign)1{sup {+-}}}. We find that the mass reach is critically dependent upon {delta}m{sub {chi}}{sub (tilde sign){sub 1}} and m{sub g(tilde sign)}-m{sub {chi}}{sub (tilde sign){sub 1{sup {+-}}. If {delta}m{sub {chi}}{sub (tilde sign){sub 1}} is sufficiently big that c{tau}({chi}(tilde sign){sub 1}{sup {+-}})(less-or-similar sign)few cm and m{sub g(tilde sign)} is large, there is a significant possibility that the limits on m{sub {chi}}{sub (tilde sign){sub 1}}{sup {+-}}} based on CERN LEP2 data cannot be extended at the Fermilab Tevatron. If c{tau}({chi}(tilde sign){sub 1}{sup {+-}})>few cm, relatively background-free signals exist that will give a clear signal of {chi}(tilde sign){sub 1}{sup {+-}} production (for some range of m{sub {chi}}{sub (tilde sign)1{sup {+-}}}) even if m{sub g(tilde sign)} is very large. (c) 2000 The American Physical Society.},
doi = {10.1103/PhysRevD.62.015002},
url = {https://www.osti.gov/biblio/20216972}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 1,
volume = 62,
place = {United States},
year = {2000},
month = {7}
}