High Energy Physics - Experiment
New submissions
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New submissions for Tue, 2 Dec 08
- [1] arXiv:0812.0267 [ps, pdf, other]
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Title: Search for Charged Higgs Bosons in e+e- Collisions at sqrts(s) = 189-209 GeVAuthors: The OPAL collaboration, et alComments: 31 pages, 13 figures, Submitted to Eur Phys J.CSubjects: High Energy Physics - Experiment (hep-ex)
A search is made for charged Higgs bosons predicted by Two-Higgs-Doublet extensions of the Standard Model (2HDM) using electron-positron collision data collected by the OPAL experiment at sqrts=189-209 GeV, corresponding to an integrated luminosity of approximately 600pb-1. Charged Higgs bosons are assumed to be pair-produced and to decay into qq, tnt or AWpm. No signal is observed. Model-independent limits on the charged Higgs-boson production cross section are derived by combining these results with previous searches at lower energies. Excluded areas on the [mHpm, BR(Hpm->TV)] plane are presented assuming BR(Hpm->tnt)+BR(Hpm->qq)=1. Under the above assumption, motivated by general 2HDM type II models, charged Higgs bosons are excluded up to a mass of 76.6GeV at 95% confidence level, independent of the branching ratio BR(Hpm->tnt). A scan of the 2HDM type I model parameter space is performed and limits on the Higgs-boson masses mHpm and mA are presented for different choices of tanb.
Cross-lists for Tue, 2 Dec 08
- [2] arXiv:0811.3411 (cross-list from hep-ph) [ps, pdf, other]
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Title: Neutrino Mass Hierarchy and neutron-anti-neutron Oscillation from BaryogenesisComments: 23 pages and seven figures; Fifure 4 replaced; references updated; typos correctedSubjects: High Energy Physics - Phenomenology (hep-ph); Astrophysics (astro-ph); High Energy Physics - Experiment (hep-ex)
It has been recently proposed that the matter-antimatter asymmetry of the universe may have its origin in "post-sphaleron baryogenesis" (PSB). It is a TeV scale mechanism that is testable at the LHC and other low energy experiments. In this paper we present a theory of PSB within a quark-lepton unified scheme based on the gauge group $SU(2)_L\times SU(2)_R\times SU(4)_c$ that allows a direct connection between the baryon asymmetry and neutrino mass matrix. The flavor changing neutral current constraints on the model allow successful baryogenesis only for an inverted mass hierarchy for neutrinos, which can be tested in the proposed long base line neutrino experiments. The model also predicts observable neutron--antineutron oscillation accessible to the next generation of experiments as well as TeV scale colored scalars within reach of LHC.
- [3] arXiv:0811.4169 (cross-list from hep-ph) [ps, pdf, other]
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Title: HiggsBounds: Confronting Arbitrary Higgs Sectors with Exclusion Bounds from LEP and the TevatronComments: 58 pages, 15 tables, 7 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
HiggsBounds is a computer code that tests theoretical predictions of models with arbitrary Higgs sectors against the exclusion bounds obtained from the Higgs searches at LEP and the Tevatron. The included experimental information comprises exclusion bounds at 95% C.L. on topological cross sections. In order to determine which search topology has the highest exclusion power, the program also includes, for each topology, information from the experiments on the expected exclusion bound, which would have been observed in case of a pure background distribution. Using the predictions of the desired model provided by the user as input, HiggsBounds determines the most sensitive channel and tests whether the considered parameter point is excluded at the 95% C.L. HiggsBounds is available as a Fortran 77 and Fortran 90 code. The code can be invoked as a command line version, a subroutine version and an online version. Examples of exclusion bounds obtained with HiggsBounds are discussed for a model with a fourth generation of quarks and leptons and for the Minimal Supersymmetric Standard Model with and without CP-violation. The experimental information on the exclusion bounds currently implemented in HiggsBounds will be updated as new results from the Higgs searches become available.
- [4] arXiv:0812.0345 (cross-list from physics.ins-det) [ps, pdf, other]
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Title: Probing For New Physics and Detecting non linear vacuum QED effects using gravitational wave interferometer antennasSubjects: Instrumentation and Detectors (physics.ins-det); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
Low energy non linear QED effects in vacuum have been predicted since 1936 and have been subject of research for many decades. Two main schemes have been proposed for such a 'first' detection: measurements of ellipticity acquired by a linearly polarized beam of light passing through a magnetic field and direct light-light scattering. The study of the propagation of light through an external field can also be used to probe for new physics such as the existence of axion-like particles and millicharged particles. Their existence in nature would cause the index of refraction of vacuum to be different from unity in the presence of an external field and dependent of the polarization direction of the light propagating. The major achievement of reaching the project sensitivities in gravitational wave interferometers such as LIGO an VIRGO has opened the possibility of using such instruments for the detection of QED corrections in electrodynamics and for probing new physics at very low energies. In this paper we discuss the difference between direct birefringence measurements and index of refraction measurements. We propose an almost parasitic implementation of an external magnetic field along the arms of the VIRGO interferometer and discuss the advantage of this choice in comparison to a previously proposed configuration based on shorter prototype interferometers which we believe is inadequate. Considering the design sensitivity in the strain, for the near future VIRGO+ interferometer, of $h<2\cdot10^{-23} \frac{1}{\sqrt{\rm Hz}}$ in the range 40 Hz $- 400$ Hz leads to a variable dipole magnet configuration at a frequency above 20 Hz such that $B^{2}D \ge 13000$ T$^{2}$m/$\sqrt{\rm Hz}$ for a `first' vacuum non linear QED detection.
Replacements for Tue, 2 Dec 08
- [5] arXiv:0803.0696 (replaced) [ps, pdf, other]
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Title: Can one measure C-odd asymmetry in e+e- --> pi+pi-Comments: 4 pages, 2 figures, 1 Table (revised version)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
- [6] arXiv:0804.1822 (replaced) [ps, pdf, other]
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Title: A possible signature of new physics at BES-IIIComments: 5 pages, 3 figures, mini-review, accepted by Chinese Physics C (HEP & NP)Subjects: High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
- [7] arXiv:0808.2016 (replaced) [ps, pdf, other]
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Title: Three-flavour neutrino oscillation updateComments: 11 pages, 4 figures, matches published versionJournal-ref: NewJ.Phys.10:113011,2008Subjects: High Energy Physics - Phenomenology (hep-ph); Astrophysics (astro-ph); High Energy Physics - Experiment (hep-ex)
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