arXiv subjects

P. M. Zerwas

Publications and source records attributed to P. M. Zerwas.

At least 37 records · Page 2Linked to original sources

arXiv2006

ILC: Physics Scenarios

Experiments in the energy range from the scale of electroweak symmetry breaking to the TeV scale are expected to be crucial for unraveling the microscopic structure of matter and forces. The high precision which should be achieved in experiments at lepton colliders, is a necessary ingredient for providing a comprehensive picture of the mechanism breaking the electroweak symmetries and generating mass, the unification of forces, involving most likely supersymmetry, and the structure of space-time at small distances. In addition, clarifying the nature of the particles which build up cold dark matter in the universe, needs a lepton collider to match the high experimental precision which will be reached in cosmology experiments.

hep-ph↗

arXiv2005

Reconstructing Supersymmetry at ILC/LHC

Coherent analyses of experimental results from LHC and ILC will allow us to draw a comprehensive and precise picture of the supersymmetric particle sector. Based on this platform the fundamental supersymmetric theory can be reconstructed at the high scale which is potentially close to the Planck scale. This procedure will be reviewed for three characteristic examples: minimal supergravity as the paradigm; a left-right symmetric extension incorporating intermediate mass scales; and a specific realization of string effective theories.

hep-ph↗

arXiv2005

Elements of Physics with a Photon Collider

After a brief description of the basic principle of a photon collider, we summarize the physics potential of such a facility at high energies. Unique opportunities are provided in supersymmetric theories for the discovery of heavy scalar and pseudoscalar Higgs bosons as well as selectrons and e-sneutrinos.

hep-ph↗

arXiv2005

Rompimiento de la Simetria Electrodebil y la Fisica del Higgs: Conceptos Basicos

Presentamos una introduccion a los conceptos basicos del rompimiento de la simetria electrodebil y la fisica del Higgs dentro del Modelo Estandar y sus extensiones supersimetricas. Se presenta tambien una breve perspectiva general de mecanismos alternativos del rompimiento de la simetria. Ademas de las bases teoricas, se discute el estado actual de la fisica experimental del Higgs y sus implicaciones para futuros experimentos en el LHC y en colisionadores lineales e+e-.

hep-ph↗

arXiv2005

Determining Sneutrino Masses and Physical Implications

In some areas of supersymmetry parameter space, sneutrinos are lighter than the charginos and the next-to-lightest neutralino, and they decay into the invisible neutrino plus lightest-neutralino channel with probability one. In such a scenario they can be searched for in decays of charginos that are pair-produced in e+e- collisions, and in associated sneutrino-chargino production in photon-electron collisions. The sneutrino properties can be determined with high accuracy from the edges of the decay energy spectra in the first case and from threshold scans in the second. In the final part of the report we investigate the mass difference of sneutrinos and charged sleptons between the third and the first two generations in seesaw-type models of the neutrino/sneutrino sector. For a wide range these mass differences are sensitive to the seesaw scale.

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arXiv2005

Determining the Stau Trilinear Coupling A_tau in Supersymmetric Higgs Decays

The measurement of the trilinear couplings A in the part of the Lagrangian which breaks supersymmetry softly will be a difficult experimental task. In this report the heavy Higgs decays H,A -> stau_1 stau_2 to stau pairs are investigated for measuring the stau trilinear coupling A_tau. Based on detailed simulations of signal and backgrounds for a specific reference point in future high luminosity e+e- linear collider experiments, it is concluded that the parameter $_tau can be determined with a precision at the 10% level in the region of moderate to large tan(beta).

hep-ph↗

arXiv2005

Pair production of scalar leptoquarks at the LHC

Theoretical predictions for the production cross sections of leptoquarks at the CERN LHC are presented including higher-order QCD corrections. These corrections reduce the dependence on the renormalization/factorization scales significantly. Moreover, they are required to exploit the leptoquark mass reach of the LHC experiments. In this sequel to an earlier analysis performed for the Tevatron collider we extend the leptoquark analysis to the LHC energy.

hep-ph↗

arXiv2005

Sneutrino Production at e+e- Linear Colliders: Addendum to Slepton Production

Complementing the preceding study of charged scalar leptons, the sector of the neutral scalar leptons, sneutrinos, is investigated in a high-precision analysis for future e+e- linear colliders. The theoretical predictions for the cross-sections are calculated at the thresholds for non-zero widths and in the continuum including higher-order corrections at the one-loop level. Methods for measuring the sneutrino masses and the electron-sneutrino-gaugino Yukawa couplings are presented, addressing theoretical problems specific for the sneutrino channels.

hep-ph↗

arXiv2004

Sleptons: Masses, Mixings, Couplings

This presentation summarizes recent work of different groups on the analysis of slepton parameters at a TeV linear collider. In particular, measurements of the masses, mixings and Yukawa couplings for the neutral and charged sleptons of the first/second generation and for the charged slepton sector of the third generation are reviewed. For all relevant processes, threshold corrections and higher order corrections in the continuum are available, thus allowing high-precision analyses of the parameters in the slepton sector.

hep-ph↗

arXiv2004

H/A Higgs Mixing in CP-Noninvariant Supersymmetric Theories

For large masses, the two heavy neutral Higgs bosons are nearly degenerate in many 2--Higgs doublet models, and particularly in supersymmetric models. In such a scenario the mixing between the states can be very large if the theory is CP-noninvariant. We analyze the formalism describing this configuration, and we point to some interesting experimental consequences.

hep-ph↗

arXiv2004

The Neutralino Sector of the Next-to-Minimal Supersymmetric Standard Model

The Next-to-Minimal Supersymmetric Standard Model (NMSSM) includes a Higgs iso-singlet superfield in addition to the two Higgs doublet superfields of the minimal extension. If the Higgs fields remain weakly coupled up to the GUT scale, as naturally motivated by the concept of supersymmetry, the mixing between singlet and doublet fields is small and can be treated perturbatively. The mass spectrum and mixing matrix of the neutralino sector can be analyzed analytically and the structure of this 5-state system is under good theoretical control. We also determine decay modes and production channels in sfermion cascade decays to these particles at the LHC and pair production in e+e- colliders.

hep-ph↗

arXiv2004

SUSY Parameter Analysis at TeV and Planck Scales

Coherent analyses at future LHC and LC experiments can be used to explore the breaking mechanism of supersymmetry and to reconstruct the fundamental theory at high energies, in particular at the grand unification scale. This will be exemplified for minimal supergravity.

hep-ph↗

arXiv2004

Tau tau Fusion to SUSY Higgs Bosons at a Photon Collider: Measuring tan(beta)

Tau tau fusion to light h and heavy H,A Higgs bosons is investigated in the Minimal Supersymmetric Standard Model (MSSM) at a photon collider as a promising channel for measuring large values of tan(beta). For standard design parameters of a photon collider an error close to unity, uniform for tan(beta) above 10, may be expected, improving on complementary measurements at LHC and e+e- linear colliders.

hep-ph↗

arXiv2004

Determining tan(beta) in ττFusion to SUSY Higgs Bosons at a Photon Collider

We investigate ττfusion to light h and heavy H and A Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM) at a photon collider as a promising channel for measuring large values of tan(beta). For standard design parameters of a photon collider an error Δtan(beta) \sim 1, uniformly for tan(beta) \gsim 10, may be expected, improving on complementary measurements at the LHC and e+e- linear colliders.

hep-ph↗

arXiv2004

Reconstructing Supersymmetric Theories by Coherent LHC / LC Analyses

Supersymmetry analyses will potentially be a central area for experiments at the LHC and at a future e+ e- linear collider. Results from the two facilities will mutually complement and augment each other so that a comprehensive and precise picture of the supersymmetric world can be developed. We will demonstrate in this report how coherent analyses at LHC and LC experiments can be used to explore the breaking mechanism of supersymmetry and to reconstruct the fundamental theory at high energies, in particular at the grand unification scale. This will be exemplified for minimal supergravity in detailed experimental simulations performed for the Snowmass reference point SPS1a.

hep-ph↗

arXiv2004

Slepton Production at e+e- and e-e- Linear Colliders

High-precision analyses are presented for the production of scalar sleptons, selectrons and smuons in supersymmetric theories, at future e+e- and e-e- linear colliders. Threshold production can be exploited for measurements of the selectron and smuon masses, an essential ingredient for the reconstruction of the fundamental supersymmetric theory at high scales. The production of selectrons in the continuum will allow us to determine the Yukawa couplings in the selectron sector, scrutinizing the identity of the Yukawa and gauge couplings, which is a basic consequence of supersymmetry. The theoretical predictions are elaborated at the one-loop level in the continuum, while at threshold non-zero width effects and Sommerfeld rescattering corrections are included. The phenomenological analyses are performed for e+e- and e-e- linear colliders with energy up to about 1 TeV and with high integrated luminosity up to 1 ab^-1 to cover the individual slepton channels separately with high precision.

hep-ph↗

arXiv2003

The Higgs Sector of the Next-to-Minimal Supersymmetric Standard Model

The Higgs boson spectrum of the Next-to-Minimal Supersymmetric Standard Model is examined. The model includes a singlet Higgs field S in addition to the two Higgs doublets of the minimal extension. `Natural' values of the parameters of the model are motivated by their renormalization group running and the vacuum stability. The qualitative features of the Higgs boson masses are dependent on how strongly the Peccei-Quinn U(1) symmetry of the model is broken, measured by the self-coupling of the singlet field in the superpotential. We explore the Higgs boson masses and their couplings to gauge bosons for various representative scenarios.

hep-ph↗

arXiv2003

Polarisation in Sfermion Decays: Determining \tanβand Trilinear Couplings

The basic parameters of supersymmetric theories can be determined at future e^+e^- linear colliders with high precision. We investigate in this report how polarisation measurements in \tildeτ and \tilde{t} or \tilde{b} decays to τleptons and t quarks plus neutralinos or charginos can be used to measure \tanβ(in particular for large values) and to determine the trilinear couplings A_τ, A_t and A_b in sfermion pair production.

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