42 research outputs found
A Comprehensive Analysis of Electric Dipole Moment Constraints on CP-violating Phases in the MSSM
We analyze the constraints placed on individual, flavor diagonal CP-violating
phases in the minimal supersymmetric extension of the Standard Model (MSSM) by
current experimental bounds on the electric dipole moments (EDMs) of the
neutron, Thallium, and Mercury atoms. We identify the four CP-violating phases
that are individually highly constrained by current EDM bounds, and we explore
how these phases and correlations among them are constrained by current EDM
limits. We also analyze the prospective implications of the next generation of
EDM experiments. We point out that all other CP-violating phases in the MSSM
are not nearly as tightly constrained by limits on the size of EDMs. We
emphasize that a rich set of phenomenological consequences is potentially
associated with these generically large EDM-allowed phases, ranging from B
physics, electroweak baryogenesis, and signals of CP-violation at the CERN
Large Hadron Collider and at future linear colliders. Our numerical study takes
into account the complete set of contributions from one- and two-loop EDMs of
the electron and quarks, one- and two-loop Chromo-EDMs of quarks, the Weinberg
3-gluon operator, and dominant 4-fermion CP-odd operator contributions,
including contributions which are both included and not included yet in the
CPsuperH2.0 package. We also introduce an open-source numerical package, 2LEDM,
which provides the complete set of two-loop electroweak diagrams contributing
to the electric dipole moments of leptons and quarks.Comment: 23 pages, 11 figures; v2: references added, minor change
Heavy fermions and two loop electroweak corrections to
Applying effective Lagrangian method and on-shell scheme, we analyze the
electroweak corrections to the rare decay from some
special two loop diagrams in which a closed heavy fermion loop is attached to
the virtual charged gauge bosons or Higgs. At the decoupling limit where the
virtual fermions in inner loop are much heavier than the electroweak scale, we
verify the final results satisfying the decoupling theorem explicitly when the
interactions among Higgs and heavy fermions do not contain the nondecoupling
couplings. Adopting the universal assumptions on the relevant couplings and
mass spectrum of new physics, we find that the relative corrections from those
two loop diagrams to the SM theoretical prediction on the branching ratio of
can reach 5% as the energy scale of new physics
GeV.Comment: 30 pages,4 figure
Solar fusion cross sections. II. The pp chain and CNO cycles
We summarize and critically evaluate the available data on nuclear fusion
cross sections important to energy generation in the Sun and other
hydrogen-burning stars and to solar neutrino production. Recommended values and
uncertainties are provided for key cross sections, and a recommended spectrum
is given for 8B solar neutrinos. We also discuss opportunities for further
increasing the precision of key rates, including new facilities, new
experimental techniques, and improvements in theory. This review, which
summarizes the conclusions of a workshop held at the Institute for Nuclear
Theory, Seattle, in January 2009, is intended as a 10-year update and
supplement to Reviews of Modern Physics 70 (1998) 1265.Comment: 54 pages, 20 figures, version to be published in Reviews of Modern
Physics; various typos corrected and several updates mad
Slepton Discovery in Electroweak Cascade Decay
The LHC studies on the MSSM slepton sector have mostly been focused on direct
slepton Drell-Yan pair production. In this paper, we analyze the case when the
sleptons are lighter than heavy neutralinos and can appear in the on-shell
decay of neutralino states. In particular, we have studied the \chi_1^\pm
\chi_2^0 associated production, with the consequent decays of \chi_1^\pm and
\chi_2^0 via on-shell sleptons. The invariant mass of the lepton pairs,
m_{\ell\ell}, from the neutralino decay has a distinctive triangle shape with a
sharp kinematic cutoff. We discuss the utilization of this triangle shape in
m_{\ell\ell} distribution to identify the slepton signal. We studied the
trilepton plus missing E_T signal and obtained the effective cross section,
\sigma \times BR \times acceptance, that is needed for a 5\sigma discovery as a
function of the cutoff mass for the LHC with center of mass energy 14 TeV and
100 fb^{-1} integrated luminosity. Our results are model independent such that
they could be applied to other models with similar decay topology. When applied
to the MSSM under simple assumptions, it is found that with 100 fb^{-1}
integrated luminosity, a discovery reach in the left-handed slepton mass of
about 600 GeV could be reached, which extends far beyond the slepton mass reach
in the usual Drell-Yan studies.Comment: 20 pages, 5 figure
Review of Particle Physics
The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143 new measurements from 709 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 120 reviews are many that are new or heavily revised, including a new review on Machine Learning, and one on Spectroscopy of Light Meson Resonances.
The Review is divided into two volumes. Volume 1 includes the Summary Tables and 97 review articles. Volume 2 consists of the Particle Listings and contains also 23 reviews that address specific aspects of the data presented in the Listings.
The complete Review (both volumes) is published online on the website of the Particle Data Group (pdg.lbl.gov) and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary Tables and essential tables, figures, and equations from selected review articles is available in print, as a web version optimized for use on phones, and as an Android app
Neutrinos
229 pages229 pages229 pagesThe Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms
FCC-ee: The Lepton Collider: Future Circular Collider Conceptual Design Report Volume 2
In response to the 2013 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) study was launched, as an international collaboration hosted by CERN. This study covers a highest-luminosity high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh), which could, successively, be installed in the same 100 km tunnel. The scientific capabilities of the integrated FCC programme would serve the worldwide community throughout the 21st century. The FCC study also investigates an LHC energy upgrade, using FCC-hh technology. This document constitutes the second volume of the FCC Conceptual Design Report, devoted to the electron-positron collider FCC-ee. After summarizing the physics discovery opportunities, it presents the accelerator design, performance reach, a staged operation scenario, the underlying technologies, civil engineering, technical infrastructure, and an implementation plan. FCC-ee can be built with today’s technology. Most of the FCC-ee infrastructure could be reused for FCC-hh. Combining concepts from past and present lepton colliders and adding a few novel elements, the FCC-ee design promises outstandingly high luminosity. This will make the FCC-ee a unique precision instrument to study the heaviest known particles (Z, W and H bosons and the top quark), offering great direct and indirect sensitivity to new physics
FCC Physics Opportunities: Future Circular Collider Conceptual Design Report Volume 1
We review the physics opportunities of the Future Circular Collider, covering its e+e-, pp, ep and heavy ion programmes. We describe the measurement capabilities of each FCC component, addressing the study of electroweak, Higgs and strong interactions, the top quark and flavour, as well as phenomena beyond the Standard Model. We highlight the synergy and complementarity of the different colliders, which will contribute to a uniquely coherent and ambitious research programme, providing an unmatchable combination of precision and sensitivity to new physics