Publications (15)8.99 Total impact
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Article: HiggsSignals: Confronting arbitrary Higgs sectors with measurements at the Tevatron and the LHC
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ABSTRACT: HiggsSignals is a Fortran90 computer code that allows to test the compatibility of Higgs sector predictions against Higgs rates and masses measured at the LHC or the Tevatron. Arbitrary models with any number of Higgs bosons can be investigated using a model-independent input scheme based on HiggsBounds. The test is based on the calculation of a chi-squared measure from the predictions and the measured Higgs rates and masses, with the ability of fully taking into account systematics and correlations for the signal rate predictions, luminosity and Higgs mass predictions. It features two complementary methods for the test. First, the peak-centered method, in which each observable is defined by a Higgs signal rate measured at a specific hypothetical Higgs mass, corresponding to a tentative Higgs signal. Second, the mass-centered method, where the test is evaluated by comparing the signal rate measurement to the theory prediction at the Higgs mass predicted by the model. The program allows for the simultaneous use of both methods, which is useful in testing models with multiple Higgs bosons. The code automatically combines the signal rates of multiple Higgs bosons if their signals cannot be resolved by the experimental analysis. We compare results obtained with HiggsSignals to official ATLAS and CMS results for various examples of Higgs property determinations and find very good agreement. A few examples of HiggsSignals applications are provided, going beyond the scenarios investigated by the LHC collaborations. For models with more than one Higgs boson we recommend to use HiggsSignals and HiggsBounds in parallel to exploit the full constraining power of Higgs search exclusion limits and the measurements of the signal seen at around 125.5 GeV.05/2013; -
Article: Recent Developments in HiggsBounds and a Preview of HiggsSignals
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ABSTRACT: We report on recent developments in the public computer code HiggsBounds, which confronts arbitrary Higgs sector predictions with 95% C.L. exclusion limits from Higgs searches at the LEP, Tevatron and LHC experiments. We discuss in detail the performance of the Standard Model (SM) likeness test as implemented in the latest version HiggsBounds-3.8.0, whose outcome decides whether a search for a SM Higgs boson can be applied to a model beyond the SM. Furthermore, we give a preview of features in the upcoming version HiggsBounds-4.0.0 and the new program HiggsSignals, which performs a chi-squared test of Higgs sector predictions against the signal rate and mass measurements from Higgs boson analyses at the Tevatron and LHC. This is illustrated with an example where the heavier CP-even Higgs boson of the Minimal Supersymmetric Standard Model (MSSM) is considered as an explanation of the LHC Higgs signal at ~126 GeV.01/2013; -
Article: Light NMSSM Higgs bosons in SUSY cascade decays at the LHC
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ABSTRACT: An interesting feature of the next-to-minimal supersymmetric standard model (NMSSM) is that one or more Higgs bosons may be comparably light (M_{H_i}<M_Z) without being in conflict with current experimental bounds. Due to a large singlet component, their direct production in standard channels at the Large Hadron Collider (LHC) is suppressed. We demonstrate that there are good prospects for observing such a light Higgs boson in decays of heavy neutralinos and charginos. We consider an example scenario with 20 GeV < M_{H_1} < M_Z and show that a large fraction of the cascade decays of gluinos and squarks involves the production of at least one Higgs boson. Performing a Monte Carlo analysis at the level of fast detector simulation, it is demonstrated how the Higgs signal can be separated from the main backgrounds, giving access to the Yukawa coupling of the Higgs to bottom quarks. Analyzing the resulting b\bar{b} mass spectrum could provide an opportunity for light Higgs boson discovery already with 5 fb^{-1} of LHC data at 7 TeV.08/2011; -
Article: 2HDMC - a two Higgs Doublet Model Calculator
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ABSTRACT: We present the program 2HDMC and how it can be used to explore the physics of general CP conserving two Higgs doublet models.04/2011; -
Article: Tools for charged Higgs bosons
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ABSTRACT: We review the status of publicly available software tools applicable to charged Higgs physics. A selection of codes are highlighted in more detail, focusing on new developments that have taken place since the previous charged Higgs workshop in 2008. We conclude that phenomenologists now have the tools ready to face the LHC data. A new webpage collecting charged Higgs resources is presented. Comment: Invited talk at "Prospects for charged Higgs Discovery at Colliders - CHARGED2010", September 27-30 2010, Uppsala, Sweden. 8 pages, 3 figures12/2010; -
Article: Erratum for “2HDMC - two-Higgs-doublet model calculator” [Comput. Phys. Commun. 181 (2010) 189]
Computer Physics Communications 04/2010; 181:985-985. · 3.27 Impact Factor -
Article: Erratum for "2HDMC - two-Higgs-doublet model calculator" [Comput. Phys. Commun.
Computer Physics Communications. 01/2010; 181:181. -
Article: Constraints on the two-Higgs-doublet model
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ABSTRACT: The two-Higgs-doublet model provides a simple, yet interesting, generalization of the SM Higgs sector. We study the CP-conserving version of this model with general, flavor-diagonal, Yukawa couplings. Indirect constraints are obtained from flavor physics on the charged Higgs boson mass and couplings. The relation of these bounds to those for the more specialized two-Higgs-doublet model types with a $Z_2$ symmetry is discussed. Comment: 4 pages, 3 figures. Talk given at SUSY09, Boston (MA), June 200909/2009; -
Article: 2HDMC - Two-Higgs-Doublet Model Calculator
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ABSTRACT: This manual describes the public code 2HDMC which can be used to perform calculations in a general, CP-conserving, two-Higgs-doublet model (2HDM). The program features simple conversion between different parametrizations of the 2HDM potential, a flexible Yukawa sector specification with choices of different Z_2-symmetries or more general couplings, a tree-level decay library including all two-body - and some three-body - decay modes for the Higgs bosons, and the possibility to calculate observables of interest for constraining the 2HDM parameter space, as well as theoretical constraints from positivity and unitarity. The latest version of the 2HDMC code and full documentation is available from: http://www.isv.uu.se/thep/MC/2HDMC Comment: 28 pages, no figures. Minor changes to the text, new interface to HiggsBounds described. Agrees with published version02/2009; -
Article: New angles on top quark decay to a charged Higgs Boson
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ABSTRACT: Top quarks produced in pairs are predicted to experience spin correlations. Due to the large ttbar statistics expected for the LHC, it should be possible to search for new physics effects in angular variables sensitive to these correlations. We investigate, for a general two-Higgs Doublet Model (2HDM), the charged Higgs boson decay of the top quark through the channel $t\to bH^+\to b\tau^+\nu_\tau$. Analytic results are presented on the spin analyzing coefficients for this decay mode. We then explore in some detail the correlation phenomenology in the Type II 2HDM. Finally we present a hadron-level Monte Carlo analysis, illustrating distributions in azimuthal angles which are sensitive to correlations in the transverse plane. These observables are accessible also in the tau channel, and are therefore particularly interesting for analyzing the $t\to bH^+$ decay. Comment: 9 pages, 6 figures. Submitted to the proceedings of TOP2008, Isola d'Elba, Italy09/2008; -
Article: New angles on top quark decay to a charged Higgs
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ABSTRACT: To properly discover a charged Higgs Boson ($H^\pm$) requires its spin and couplings to be determined. We investigate how to utilize $\ttbar$ spin correlations to analyze the $H^\pm$ couplings in the decay $t\to bH^+\to b\tau^+\nu_\tau$. Within the framework of a general Two-Higgs-Doublet Model, we obtain results on the spin analyzing coefficients for this decay and study in detail its spin phenomenology, focusing on the limits of large and small values for $\tan\beta$. Using a Monte Carlo approach to simulate full hadron-level events, we evaluate systematically how the $H^\pm\to\tau^\pm\nu_\tau$ decay mode can be used for spin analysis. The most promising observables are obtained from azimuthal angle correlations in the transverse rest frames of $t(\bar{t})$. This method is particularly useful for determining the coupling structure of $H^\pm$ in the large $\tan\beta$ limit, where differences from the SM are most significant.12/2007; -
Article: Prospects for the Giant Metrewave Radio Telescope to observe radio waves from ultra high energy particles interacting with the Moon
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ABSTRACT: Ultra high energy (UHE) particles of cosmic origin impact the lunar regolith and produce radio signals through the Askaryan effect, signals that can be detected by Earth based radio telescopes. We calculate the expected sensitivity for observation of such events at the Giant Metrewave Radio Telescope, both for UHE cosmic rays (CR) and UHE neutrino interactions. We find that for 30 days of observation time a significant number of detectable events are expected, above 1020 eV, for UHE CR or neutrino fluxes close to the current limits. Null detection over a period of 30 days will lower the experimental bounds by a magnitude competitive with both present and future experiments at the very highest energies.Journal of Cosmology and Astroparticle Physics 11/2007; 2007(11):022. · 5.72 Impact Factor -
Article: Prospects for GMRT to Observe Radio Waves from UHE Particles Interacting with the Moon
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ABSTRACT: Ultra high energy (UHE) particles of cosmic origin impact the lunar regolith and produce radio signals through Askaryan effect, signals that can be detected by Earth based radio telescopes. We calculate the expected sensitivity for observation of such events at the Giant Metrewave Radio Telescope (GMRT), both for UHE cosmic rays (CR) and UHE neutrino interactions. We find that for 30 days of observation time a significant number of detectable events is expected above $10^{20}$ eV for UHECR or neutrino fluxes close to the current limits. Null detection over a period of 30 days will lower the experimental bounds on UHE particle fluxes by magnitudes competitive to both present and future experiments at the very highest energies.09/2007; -
Article: Lunar Satellite Detection of Ultra-High Energy Neutrinos with the Use of Radio Methods
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ABSTRACT: Neutrinos interact with matter only through weak processes with low cross-section. To detect cosmic neutrinos most efforts have relied on the detection of visible Vavilov-Cerenkov light in detectors embedded in the target volumes. To access the decreasing flux of ultra-high energy neutrinos, far above 1 PeV, ideas on how to increase the detection volume by observing coherent radio frequency emission caused by the Askaryan effect have been put forward. Here we describe how a satellite in lunar orbit equipped with an electromagnetic vector sensor could detect Askaryan pulses induced by neutrinos interacting with the moon. The threshold neutrino energy is found to be 50 EeV for this setup, and the sensitivity is determined from simulations. A model dependent event rate of 2.2 events per year is calculated.10/2005; -
Article: 2HDMC – two-Higgs-doublet model calculator
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ABSTRACT: We describe the public C++ code 2HDMC which can be used to perform calculations in a general, CP-conserving, two-Higgs-doublet model (2HDM). The program features simple conversion between different parametrizations of the 2HDM potential, a flexible Yukawa sector specification with choices of different Z2-symmetries or more general couplings, a decay library including all two-body – and some three-body – decay modes for the Higgs bosons, and the possibility to calculate observables of interest for constraining the 2HDM parameter space, as well as theoretical constraints from positivity and unitarity. The latest version of the 2HDMC code and full documentation is available from: http://www.isv.uu.se/thep/MC/2HDMC.Program summaryProgram title:2HDMCCatalogue identifier: AEFI_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFI_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: GNU GPLNo. of lines in distributed program, including test data, etc.: 12 032No. of bytes in distributed program, including test data, etc.: 90 699Distribution format: tar.gzProgramming language: C++Computer: Any computer running LinuxOperating system: LinuxRAM: 5 MbClassification: 11.1External routines: GNU Scientific Library (http://www.gnu.org/software/gsl/)Nature of problem: Determining properties of the potential, calculation of mass spectrum, couplings, decay widths, oblique parameters, muon g−2, and collider constraints in a general two-Higgs-doublet model.Solution method: From arbitrary potential and Yukawa sector, tree-level relations are used to determine Higgs masses and couplings. Decay widths are calculated at leading order, including FCNC decays when applicable. Decays to off-shell vector bosons are obtained by numerical integration. Observables are computed (analytically or numerically) as function of the input parameters.Restrictions: CP-violation is not treated.Running time: Less than 0.1 s on a standard PCComputer Physics Communications.
Top co-authors
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Institutions
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2007–2010
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Uppsala University
- Department of Physics and Astronomy
Uppsala, Uppsala, Sweden
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2005
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Swedish Institute of Space Physics
Kiruna, Norrbotten, Sweden
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