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MSSM Higgs boson searches at the Tevatron and the LHC: Impact of different benchmark scenarios

Description: The Higgs boson search has shifted from LEP2 to the Tevatron and will subsequently move to the LHC. The current limits from the Tevatron and the prospective sensitivities at the LHC are often interpreted in specific MSSM scenarios. For heavy Higgs boson production and subsequent decay into b{bar b} or {tau}{sup +}{tau}{sup -}, the present Tevatron data allow to set limits in the M{sub A}-tan {beta} plane for small M{sub A} and large tan {beta} values. Similar channels have been explored for the LHC, where the discovery reach extends to higher values of M{sub A} and smaller tan {beta}. Searches for MSSM charged Higgs bosons, produced in top decays or in association with top quarks, have also been investigated at the Tevatron and the LHC. We analyze the current Tevatron limits and prospective LHC sensitivities. We discuss how robust they are with respect to variations of the other MSSM parameters and possible improvements of the theoretical predictions for Higgs boson production and decay. It is shown that the inclusion of supersymmetric radiative corrections to the production cross sections and decay widths leads to important modifications of the present limits on the MSSM parameter space. The impact on the region where only the lightest MSSM Higgs boson can be detected at the LHC is also analyzed. We propose to extend the existing benchmark scenarios by including additional values of the higgsino mass parameter {mu}. This affects only slightly the search channels for a SM-like Higgs boson, while having a major impact on the searches for non-standard MSSM Higgs bosons.
Date: November 1, 2005
Creator: Carena, Marcela S.; Heinemeyer, S.; Wagner, C. E. M. & Weiglein, G.
Partner: UNT Libraries Government Documents Department

Challenges for MSSM Higgs searches at hadron colliders

Description: In this article we analyze the impact of B-physics and Higgs physics at LEP on standard and non-standard Higgs bosons searches at the Tevatron and the LHC, within the framework of minimal flavor violating supersymmetric models. The B-physics constraints we consider come from the experimental measurements of the rare B-decays b {yields} s{gamma} and B{sub u} {yields} {tau}{nu} and the experimental limit on the B{sub s} {yields} {mu}{sup +}{mu}{sup -} branching ratio. We show that these constraints are severe for large values of the trilinear soft breaking parameter A{sub t}, rendering the non-standard Higgs searches at hadron colliders less promising. On the contrary these bounds are relaxed for small values of A{sub t} and large values of the Higgsino mass parameter {mu}, enhancing the prospects for the direct detection of non-standard Higgs bosons at both colliders. We also consider the available ATLAS and CMS projected sensitivities in the standard model Higgs search channels, and we discuss the LHC's ability in probing the whole MSSM parameter space. In addition we also consider the expected Tevatron collider sensitivities in the standard model Higgs h {yields} b{bar b} channel to show that it may be able to find 3 {sigma} evidence in the B-physics allowed regions for small or moderate values of the stop mixing parameter.
Date: April 1, 2007
Creator: Carena, Marcela S.; Menon, A. & Wagner, C. E. M.
Partner: UNT Libraries Government Documents Department

Suggestions for benchmark scenarios for MSSM Higgs Boson searches at hadron colliders.

Description: The Higgs boson search has shifted from LEP2 to the Tevatron and will subsequently move to the LHC. Due to the different initial states, the Higgs production and decay channels relevant for Higgs boson searches were different at LEP2 to what they are at hadron colliders. They suggest new benchmark scenarios for the MSSM Higgs boson search at hadron colliders that exemplify the phenomenology of different parts of the MSSM parameter space. Besides the m{sub h}{sup max} scenario and the no-mixing scenario used in the LEP2 Higgs boson searches, they propose two new scenarios. In one the main production channel at the LHC, gg {yields} h, is suppressed. In the other, important Higgs decay channels at the Tevatron and at the LCH, h {yields} b{bar b} and h {yields} {tau}{sup +}{tau}{sup -}, are suppressed. All scenarios evade the LEP2 constraints for nearly the whole M{sub A}-tan {beta}-plane.
Date: April 15, 2002
Creator: Carena, M.; Heinemeyer, S.; Wagner, C.E.M. & Weiglein, G.
Partner: UNT Libraries Government Documents Department

Constraints on B and Higgs physics in minimal low energy supersymmetric models

Description: We study the implications of minimal flavor violating low energy supersymmetry scenarios for the search of new physics in the B and Higgs sectors at the Tevatron collider and the LHC. We show that the already stringent Tevatron bound on the decay rate B{sub s} {yields} {mu}{sup +}{mu}{sup -} sets strong constraints on the possibility of generating large corrections to the mass difference {Delta} M{sub s} of the B{sub s} eigenstates. We also show that the B{sub s} {yields} {mu}{sup +}{mu}{sup -} bound together with the constraint on the branching ratio of the rare decay b {yields} s{gamma} has strong implications for the search of light, non-standard Higgs bosons at hadron colliders. In doing this, we demonstrate that the former expressions derived for the analysis of the double penguin contributions in the Kaon sector need to be corrected by additional terms for a realistic analysis of these effects. We also study a specific non-minimal flavor violating scenario, where there are flavor changing gluino-squark-quark interactions, governed by the CKM matrix elements, and show that the B and Higgs physics constraints are similar to the ones in the minimal flavor violating case. Finally we show that, in scenarios like electroweak baryogenesis which have light stops and charginos, there may be enhanced effects on the B and K mixing parameters, without any significant effect on the rate of B{sub s} {yields} {mu}{sup +}{mu}{sup -}.
Date: March 1, 2006
Creator: Carena, Marcela; Menon, A.; Noriega-Papaqui, R.; Szynkman, A. & Wagner, C. E. M.
Partner: UNT Libraries Government Documents Department

The Snowmass points and slopes : benchmarks for SUSY searches.

Description: The ''Snowmass Points and Slopes'' (SPS) are a set of benchmark points and parameter lines in the MSSM parameter space corresponding to different scenarios in the search for Supersymmetry at present and future experiments. This set of benchmarks was agreed upon at the 2001 ''Snowmass Workshop on the Future of Particle Physics'' as a consensus based on different existing proposals.
Date: April 15, 2002
Creator: Allanach, B. C.; Battaglia, M.; Blair, G. A.; Carena, M.; De Roeck, A. & Wagner, C. E. M.
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

Infrared fixed point solution for the top quark mass and unification of couplings in the MSSM

Description: We analyze the implications of the infrared quasi fixed point solution for the top quark mass in the Minimal Supersymmetric Standard Model. This solution could explain in a natural way the relatively large value of the top quark mass and, if confirmed experimentally, may be suggestive of the onset of nonperturbative physics at very high energy scales. In the framework of grand unification, the expected bottom quark -- tau lepton Yukawa coupling unification is very sensitive to the fixed point structure of the top quark mass. For the presently allowed values of the electroweak parameters and the bottom quark mass, the Yukawa coupling unification implies that the top quark mass must be within ten percent of its fixed point values.
Date: August 1, 1993
Creator: Bardeen, W.A.; Carena, M.; Pokorski, S. & Wagner, C.E.M.
Partner: UNT Libraries Government Documents Department

High Energy Physics Division semiannual report of research activities, January 1, 2003 - June 30, 2003.

Description: This report describes the research conducted in the High Energy Physics Division of Argonne National Laboratory during the period of January 1 through June 30, 2003. Topics covered here include experimental and theoretical particle physics, advanced accelerator physics, detector development, and experimental facilities research. Lists of Division publications and colloquia are included.
Date: January 27, 2004
Creator: Spinka, H.; Nodulman, L.; Goodman, M.; Repond, J.; Cadman, R.; Ayres, D. S. et al.
Partner: UNT Libraries Government Documents Department

Fundamental physics at the intensity frontier. Report of the workshop held December 2011 in Rockville, MD.

Description: Particle physics aims to understand the universe around us. The Standard Model of particle physics describes the basic structure of matter and forces, to the extent we have been able to probe thus far. However, it leaves some big questions unanswered. Some are within the Standard Model itself, such as why there are so many fundamental particles and why they have different masses. In other cases, the Standard Model simply fails to explain some phenomena, such as the observed matter-antimatter asymmetry in the universe, the existence of dark matter and dark energy, and the mechanism that reconciles gravity with quantum mechanics. These gaps lead us to conclude that the universe must contain new and unexplored elements of Nature. Most of particle and nuclear physics is directed towards discovering and understanding these new laws of physics. These questions are best pursued with a variety of approaches, rather than with a single experiment or technique. Particle physics uses three basic approaches, often characterized as exploration along the cosmic, energy, and intensity frontiers. Each employs different tools and techniques, but they ultimately address the same fundamental questions. This allows a multi-pronged approach where attacking basic questions from different angles furthers knowledge and provides deeper answers, so that the whole is more than a sum of the parts. A coherent picture or underlying theoretical model can more easily emerge, to be proven correct or not. The intensity frontier explores fundamental physics with intense sources and ultra-sensitive, sometimes massive detectors. It encompasses searches for extremely rare processes and for tiny deviations from Standard Model expectations. Intensity frontier experiments use precision measurements to probe quantum effects. They typically investigate very large energy scales, even higher than the kinematic reach of high energy particle accelerators. The science addresses basic questions, such as: Are there new sources of ...
Date: June 5, 2012
Creator: Hewett, J.L.; Weerts, H.; Brock, R.; Butler, J.N.; Casey, B.C.K.; Lu, Z.T. et al.
Partner: UNT Libraries Government Documents Department

High Energy Physics division semiannual report of research activities.

Description: This report describes the research conducted in the High Energy Physics Division of Argonne National Laboratory during the period of July 1, 2001 through December 31, 2001. Topics covered here include experimental and theoretical particle physics, advanced accelerator physics, detector development, and experimental facilities research. Lists of Division publications and colloquia are included.
Date: August 29, 2002
Creator: Spinka, H. M.; Nodulman, L. J.; Goodman, M. C.; Repond, J.; Ayres, D. S.; Proudfoot, J. et al.
Partner: UNT Libraries Government Documents Department

High Energy Physics semiannual report of research activities. July 1, 2003 - December 31, 2003.

Description: This report describes the research conducted in the High Energy Physics Division of Argonne National Laboratory during the period of July 1 through December 31, 2003. Topics covered here include experimental and theoretical particle physics, advanced accelerator physics, detector development, and experimental facilities research. Lists of Division publications and colloquia are included.
Date: June 2, 2004
Creator: Spinka, H. M.; Nodulman, L. J.; Goodman, M. C.; Repond, J.; Ayres, D. S.; Proudfoot, J. et al.
Partner: UNT Libraries Government Documents Department

High Energy Physics Division semiannual report of research activities : July 1, 2004 - December 31, 2004.

Description: This report describes the research conducted in the High Energy Physics Division of Argonne National Laboratory during the period of July 1 through December 31, 2004. Topics covered here include experimental and theoretical particle physics, advanced accelerator physics, detector development, and experimental facilities research. Lists of Division publications and colloquia are included.
Date: June 3, 2005
Creator: Nodulman, L.; Repond, J.; Ayres, D. S.; Proudfoot, J.; Stanek, R.; Schlereth, J. et al.
Partner: UNT Libraries Government Documents Department