0000000001110806
AUTHOR
S. Berge
showing 6 related works from this author
Top-Quark Charge Asymmetry with a Jet Handle
2012
Pairs of top and antitop quarks are produced at the LHC to a large extent in association with a hard jet. We investigate the charge asymmetry in top pair + jet production in quantum chromodynamics (QCD) and with additional massive color-octet vector bosons. The total charge asymmetry at the LHC is suppressed by the large charge-symmetric background from gluon-gluon fusion. We show to what extent the asymmetry can be enhanced by suitable phase space cuts and, in particular, elaborate on the kinematics of the hard jet in the top pair + jet final state. We demonstrate that in QCD, the asymmetry amounts to -1.5% for central jets without an excessive reduction of the cross section. By applying a…
Higgs CP properties using the tau decay modes at the ILC
2013
We investigate the prospects of determining the CP nature of the 126 GeV neutral spin-0 (Higgs) boson h, discovered at the LHC, at a future linear collider. We consider the production of h by the Higgsstrahlung process and its subsequent decays to tau leptons. We investigate how precisely a possible pseudoscalar component of h can be detected by the measurement of a suitably defined angular distribution, if all major decay modes of the tau lepton are used. From our numerical simulations, we estimate the expected precision to the scalar-pseudoscalar mixing angle, including estimates of the background and of measurement uncertainties, to be 2.8 degree for Higgs-boson production at a center-of…
Strange quark parton distribution functions and implications for Drell-Yan boson production at the LHC
2012
Global analyses of parton distribution functions (PDFs) have provided incisive constraints on the up and down quark components of the proton, but constraining the other flavor degrees of freedom is more challenging. Higher-order theory predictions and new data sets have contributed to recent improvements. Despite these efforts, the strange quark parton distribution function has a sizable uncertainty, particularly in the small $x$ region. We examine the constraints from experiment and theory, and investigate the impact of this uncertainty on LHC observables. In particular, we study $W/Z$ production to see how the $s$ quark uncertainty propagates to these observables, and examine the extent t…
Determining the CP parity of Higgs bosons at the LHC in the $\tau$ to 1-prong decay channels
2008
We propose a method for determining the CP nature of a neutral Higgs boson or spin-zero resonance $\phi$ at the CERN Large Hadron Collider (LHC) in its $\phi\to\tau^{-}\tau^{+}$ decay channel. The method can be applied to any 1-prong $\tau$-decay mode, which comprise the majority of the $\tau$-lepton decays. The proposed observables allow to discriminate between pure scalar and pseudoscalar Higgs-boson states and/or between a CP-conserving and CP-violating Higgs sector. We show for the decays $\tau\to\pi\nu_{\tau}$ that the method maintains its discriminating power when measurement uncertainties are taken into account. The method will be applicable also at a future linear $e^{+}e^{-}$ colli…
How to pin down theCPquantum numbers of a Higgs boson in itsτdecays at the LHC
2011
We investigate how the $CP$ quantum numbers of a neutral Higgs boson or spin-zero resonance $\ensuremath{\Phi}$, produced at the CERN Large Hadron Collider, can be determined in its $\ensuremath{\tau}$-pair decay mode $\ensuremath{\Phi}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{\ensuremath{-}}{\ensuremath{\tau}}^{+}$. We use a method [S. Berge and W. Bernreuther, Phys. Lett. B 671, 470 (2009).] based on the distributions of two angles and apply it to the major 1-prong $\ensuremath{\tau}$ decays. We show for the resulting dilepton, lepton-pion, and two-pion final states that appropriate selection cuts significantly enhance the discriminating power of these observables. From our analysis we…
Tevatron-for-LHC Report: Higgs
2006
The search for Higgs bosons in both the standard model and its extensions is well under way at the Tevatron. As the integrated luminosity collected increases into the multiple inverse femptobarn range, these searches are becoming very interesting indeed. Meanwhile, the construction of the Large Hadron Collider (LHC) and its associated experiments at CERN are nearing completion. In this TeV4LHC workshop, it was realized that any experience at the Tevatron with respect to backgrounds, experimental techniques and theoretical calculations that can be verified at the Tevatron which have relevance for future measurements at the LHC were important. Studies and contributions to these efforts were m…