Particle Physics

Displaying 325 - 336 of 487

No GUTs, All Glory: Charge Quantization and the Standard Model from Nonlinear Sigma Models

John Kehayias University of Tokyo
December 06, 2013

PIRSA:13120056
Particle Physics
BBN and the Unnatural Weak Scale

David Pinner University of California, Berkeley
December 05, 2013

PIRSA:13120058
Particle Physics
Using the Higgs as a Direct Probe of New Physics

Michael Park Rutgers University
December 05, 2013

PIRSA:13120050
Particle Physics
Jets Without Jets

Daniele Bertolini Massachusetts Institute of Technology (MIT)
December 04, 2013

PIRSA:13120052
Particle Physics
Fully exploring exotic production of the 125 GeV Higgs

Felix Yu Fermi National Accelerator Laboratory (Fermilab)
December 03, 2013

PIRSA:13120047
Particle Physics
Cornering Gluinos at the LHC

Jared Evans Rutgers University
December 02, 2013

PIRSA:13120057
Particle Physics
Classical Space Times from S Matrices

Ira Rothstein Carnegie Mellon University
November 26, 2013

PIRSA:13110053
Particle Physics
New Light Species and the CMB - Joint Cosmology/Particle Physics Seminar

Christopher Brust
November 19, 2013

PIRSA:13110051
Particle Physics
Baryogenesis from WIMPs
November 12, 2013

PIRSA:13110046
Particle Physics
Induced Electroweak Symmetry Breaking and Supersymmetry

Jamison Galloway New York University (NYU)
November 05, 2013

PIRSA:13110050
Particle Physics
Split Dirac Supersymmetry and a Higgsino LSP
November 01, 2013

PIRSA:13110052
Particle Physics
Minimal Distances and the RG Flow
October 29, 2013

PIRSA:13100069
Particle Physics

No GUTs, All Glory: Charge Quantization and the Standard Model from Nonlinear Sigma Models

John Kehayias University of Tokyo
December 06, 2013

PIRSA:13120056
Particle Physics
I will present recent and ongoing work in collaboration with Tsutomu Yanagida and Simeon Hellerman (arXiv:1309.0692 and 1312.xxxx) on a new way to obtain charge quantization, without a GUT or monopole solution. In the CP^1 model, SU(2)_G/U(1)_H, consistency conditions for a charged field and its transformation properties over the entire group manifold lead to a charge quantization condition. By gauging the U(1)_H and identifying it with hypercharge, we find charge quantization in the SM without a monopole or GUT, purely from the structure and dynamics of the nonlinear sigma model. This is easily extended to CP^2 and general CP^k models. Phenomenologically, the CP^1 model has a fractionally charged stable Nambu-Goldstone boson (NGB), which has intriguing applications to nuclear physics and dark matter. The CP^2 model has the Higgs as the NGB. With some additional minor assumptions, anomaly freedom then leads to the matter content of a generation in the SM.
BBN and the Unnatural Weak Scale

David Pinner University of California, Berkeley
December 05, 2013

PIRSA:13120058
Particle Physics
The discovery of a perturbatively-coupled, 125 GeV Higgs, together with the absence of LHC signals for supersymmetry, places the principle of naturalness under tension. In this talk I will discuss the possibility that the weak scale is unnatural, with its value determined environmentally in the landscape. In particular, this environmental selection may be driven by BBN: as the weak scale is increased, the abundance of Hydrogen in the early universe is rapidly depleted. That our own universe contains an O(1) fraction of primordial Helium arises as a conspiracy among the weak scale, the neutron-proton mass difference, and the planck scale.
Using the Higgs as a Direct Probe of New Physics

Michael Park Rutgers University
December 05, 2013

PIRSA:13120050
Particle Physics
The discovery of the Higgs boson marks the first direct probe into the mechanism of electroweak symmetry breaking. All evidence currently points to the fact that electroweak symmetry is broken by at least one fundamental scalar, and naturalness remains the most compelling reason to expect additional degrees of freedom at the weak scale. This talk will describe some ideas for how to utilize powerful and proven experimental techniques, in conjunction with the fact that observables directly related to the Higgs boson are now experimentally accessible, to make concrete statements about the existence of possible new degrees of freedom at the weak scale.
Jets Without Jets

Daniele Bertolini Massachusetts Institute of Technology (MIT)
December 04, 2013

PIRSA:13120052
Particle Physics
Jets are key tools for physics at the LHC. Usually, jets are identified through a jet algorithm. In this talk, I will present an alternative way of thinking about jets, by showing how a broad class of inclusive jet-based observables can be replaced by event shapes. These event shapes do not require any jet clustering, but they still implement a jet-like pT cut on "jets" with an R-like radius. I will discuss various applications, including event selection at trigger-level, event-wide trimming, and alternative definitions for boosted objects identifiers.
Fully exploring exotic production of the 125 GeV Higgs

Felix Yu Fermi National Accelerator Laboratory (Fermilab)
December 03, 2013

PIRSA:13120047
Particle Physics
I consider the effects of exotic production modes of the 125 GeV Higgs and their impact on Higgs searches and the Higgs discovery. I emphasize that new production modes have been largely overlooked in contemporary tests of the Standard Model nature of the Higgs boson but experimental tests of exotic production modes are viable now or will be soon. I present a couple explicit examples of exotic production arising from chargino-neutralino associated production in the MSSM. As a corollary of this work, I point out that current Higgs coupling fits do not adequately explore the complete space of new physics deviations possible in Higgs measurements.
Cornering Gluinos at the LHC

Jared Evans Rutgers University
December 02, 2013

PIRSA:13120057
Particle Physics
Gluinos are expected to be light for a natural electroweak scale, but the LHC has not seen them yet. Many possibilities have been proposed to hide natural gluinos in the LHC data, but are these methods really effective? In this talk, I will discuss the current status of kinematically accessible gluinos. By noting the most common features - MET, tops, and high multiplicity - which pervade natural gluino decays, I will argue that there are few places left to hide. I will briefly discuss the remaining weaknesses in LHC coverage and how to bolster them.
Classical Space Times from S Matrices

Ira Rothstein Carnegie Mellon University
November 26, 2013

PIRSA:13110053
Particle Physics
Progress in calculating S matrix elements have shown that the malicious redundancies in non-linear gauge theories can be circumvented by utilizing unitarity methods in conjunction with BCFW recursion relations. When calculating in this fashion all of the interaction vertices beyond the three point function can be ignored. This simplification is especially useful in gravity which contains an infinite number of such non-linear interactions. It is natural to ask whether off-shell quantities, such as classical solutions, can also be generated using only the three point vertex. In this talk I will show that this is indeed the case by extracting classical solutions to GR from on-hell two to two scattering S-matrix elements. In so doing we will completely circumvent the action as well as the equations of motion. The only inputs will be Lorentz invariance, the existence of a massless spin-two particle and locality. Because of the double copy relation this implies there exists, a yet to be understood, connection between solutions to Yang-Mills theory and Gravity. I will also discuss how this technique can be used to simplify calculations of higher order post-Newtonian corrections to gravitational potentials relevant to the problem of binary inspirals.
New Light Species and the CMB - Joint Cosmology/Particle Physics Seminar

Christopher Brust
November 19, 2013

PIRSA:13110051
Particle Physics
The effective number of neutrino species in our universe, Neff, is capable of probing the presence of new light or massless species in our universe. I will first review relevant facts about both CMB measurements of new light species and thermodynamics in the early universe. Then, I will present the effects of many models of BSM physics containing new light species on the CMB, including models containing eV-scale sterile neutrinos compatible with anomalies in neutrino experiments, and interpret the compatibility of the parameter space of these models in terms of the recent results from the Planck satellite. I will argue that the bounds on couplings obtained from the Planck measurement of the CMB are competitive with bounds coming from other areas of physics.
Baryogenesis from WIMPs
November 12, 2013

PIRSA:13110046
Particle Physics
We propose a robust, unified framework, in which the similar baryon and dark matter cosmic abundances both arise from the physics of weakly interacting massive particles (WIMPs), with the rough quantitative success of the so-called “WIMP miracle”. In particular the baryon asymmetry arises from the decay of a meta-stable WIMP after its thermal freezeout at or below the weak scale. A minimal model and its embedding in R-parity violating (RPV) natural SUSY are studied as examples. The new mechanism saves RPV SUSY from the potential crisis of washing out primordial baryon asymmetry. We also consider the embedding of this idea in RPV split SUSY, where the mechanism works within the minimal model, and independently motivates the mini-split scale. Phenomenological implications for the LHC and precision tests are discussed.
Induced Electroweak Symmetry Breaking and Supersymmetry

Jamison Galloway New York University (NYU)
November 05, 2013

PIRSA:13110050
Particle Physics
I'll discuss a class of supersymmetric models in which the physical Higgs mass is freed from the quartic coupling, thereby allowing for a 125 GeV Higgs state whose self-interaction can be much smaller than in the SM via a mechanism of 'induced EWSB'. This class of models provides a unique alternative to other realizations of natural SUSY, and the simplest realizations necessitate additional characteristic scalars below the TeV scale, thus altering phenomenological predictions for additional Higgses at the LHC.
Split Dirac Supersymmetry and a Higgsino LSP
November 01, 2013

PIRSA:13110052
Particle Physics
TBA
Minimal Distances and the RG Flow
October 29, 2013

PIRSA:13100069
Particle Physics
We will discuss the renormalization group flow between different classes of CFTs in four dimensions and study possible lower bounds on the "distances" between these theories.

Title	Speaker(s)	Date	Talk Type	Info
No GUTs, All Glory: Charge Quantization and the Standard Model from Nonlinear Sigma Models	John Kehayias	2013-12-06	Scientific Series	View details
BBN and the Unnatural Weak Scale	David Pinner	2013-12-05	Scientific Series	View details
Using the Higgs as a Direct Probe of New Physics	Michael Park	2013-12-05	Scientific Series	View details
Jets Without Jets	Daniele Bertolini	2013-12-04	Scientific Series	View details
Fully exploring exotic production of the 125 GeV Higgs	Felix Yu	2013-12-03	Scientific Series	View details
Cornering Gluinos at the LHC	Jared Evans	2013-12-02	Scientific Series	View details
Classical Space Times from S Matrices	Ira Rothstein	2013-11-26	Scientific Series	View details
New Light Species and the CMB - Joint Cosmology/Particle Physics Seminar	Christopher Brust	2013-11-19	Scientific Series	View details
Baryogenesis from WIMPs		2013-11-12	Scientific Series	View details
Induced Electroweak Symmetry Breaking and Supersymmetry	Jamison Galloway	2013-11-05	Scientific Series	View details
Split Dirac Supersymmetry and a Higgsino LSP		2013-11-01	Scientific Series	View details
Minimal Distances and the RG Flow		2013-10-29	Scientific Series	View details

Particle Physics

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