206,165 research outputs found
Prospects for gamma measurements at LHCb
LHCb is the dedicated B physics experiment at the LHC and is due to start
data taking later this year. Its goal is to search for new physics in very rare
processes and make precision measurements of CP violation in B decays. The CKM
angle gamma plays an important role in flavour physics in the Standard Model.
LHCb will exploit the large variety of B hadrons produced by the 14 TeV pp
collisions, performing gamma measurements to the precision of a few degrees.
Here, we will present a summary of the expected gamma sensitivities LHCb will
reach during its first years of data taking, with contributions from several
strategies in both tree and loop processes.Comment: 4 pages, 3 figures. For proceedings of 2009 Lake Louise Winter
Institute, Alberta, Canad
Optimizing Higgs factories by modifying the recoil mass
It is difficult to measure the -fusion Higgs production process () at a lepton collider with a center of mass energy of
240-250 GeV due to its small rate and the large background from the
Higgsstrahlung process with an invisible (). We construct a modified recoil mass variable, , defined using only the 3-momentum of the reconstructed Higgs
particle, and show that it can better separate the -fusion and
Higgsstrahlung events than the original recoil mass variable .
Consequently, the variable can be used to improve the
overall precisions of the extracted Higgs couplings, in both the conventional
framework and the effective-field-theory framework. We also explore the
application of the variable in the inclusive cross section
measurements of the Higgsstrahlung process, while a quantitive analysis is left
for future studies.Comment: 25 pages, 8 figure
Twin Turtles
We present an ultraviolet extension of the Twin Higgs in which the radial
mode of twin symmetry breaking is itself a pseudo-goldstone boson. This
"turtle" structure raises the scale of new colored particles in exchange for
additional states in the Higgs sector, making multiple Higgs-like scalars the
definitive signature of naturalness in this context. We explore the parametrics
and phenomenology of a concrete Twin Turtle model and demonstrate its
robustness in two different supersymmetric completions. Along the way, we also
introduce a new mechanism for inducing hard twin symmetry-breaking quartics via
soft supersymmetry breaking.Comment: 36 pages, 13 figure
750 GeV Resonance in the Gauged -Extended MSSM
Recently the ATLAS and CMS collaborations at the LHC announced their
observation of a potential 750 GeV di-photon resonance, after analyzing the
TeV LHC data. This observation has significant implications for
low-energy supersymmetry. Beyond the MSSM and the NMSSM, we study the
MSSM-extensions with an extra gauge symmetry. The anomaly cancellation
and the spontaneous breaking of the non-decoupled generically require
introducing vector-like supermultiplets (both colored and color-neutral ones)
and singlet supermultiplets, respectively. We illustrate that the potential 750
GeV resonance () can be accommodated in various mechanisms, as a
singlet-like scalar or pseudoscalar. Three benchmark scenarios are presented:
(1) vector-like quarks (VLQ) mediated ; (2) scalar
VLQ mediated ; (3) heavy scalar (pseudo-scalar)
associated production . Additionally, we notice
that the -mediated vector boson fusion production and -associated
production , if yielding a signal rate of the observed level,
might have been excluded by the searches for via Drell-Yan process at the
LHC.Comment: v3, figure update with corresponding modification in discussion,
version accepted by PL
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