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Title: Interpreting New Data from the High Energy Frontier

Abstract

This is the final technical report for DOE grant DE-SC0006389, "Interpreting New Data from the High Energy Frontier", describing research accomplishments by the PI in the field of theoretical high energy physics.

Authors:
ORCiD logo [1]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Publication Date:
Research Org.:
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1326460
Report Number(s):
DOE-MIT-0006389
DOE Contract Number:
SC0006389
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Thaler, Jesse. Interpreting New Data from the High Energy Frontier. United States: N. p., 2016. Web. doi:10.2172/1326460.
Thaler, Jesse. Interpreting New Data from the High Energy Frontier. United States. doi:10.2172/1326460.
Thaler, Jesse. 2016. "Interpreting New Data from the High Energy Frontier". United States. doi:10.2172/1326460. https://www.osti.gov/servlets/purl/1326460.
@article{osti_1326460,
title = {Interpreting New Data from the High Energy Frontier},
author = {Thaler, Jesse},
abstractNote = {This is the final technical report for DOE grant DE-SC0006389, "Interpreting New Data from the High Energy Frontier", describing research accomplishments by the PI in the field of theoretical high energy physics.},
doi = {10.2172/1326460},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2016,
month = 9
}

Technical Report:

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  • No systematic procedure currently exists for inferring the underlying physics from discrepancies observed in high energy collider data. We present Bard, an algorithm designed to facilitate the process of model construction at the energy frontier. Top-down scans of model parameter space are discarded in favor of bottom-up diagrammatic explanations of particular discrepancies, an explanation space that can be exhaustively searched and conveniently tested with existing analysis tools.
  • The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) near Geneva, Switzerland, is now the highest energy accelerator in the world, colliding protons with protons. On July 4, 2012, the two general-purpose experiments, ATLAS and the Compact Muon Solenoid (CMS) experiment, announced the observation of a particle consistent with the world’s most sought-after particle, the Higgs boson, at a mass of about 125 GeV (approximately 125 times the mass of the proton). The Higgs boson is the final missing ingredient of the standard model, in which it is needed to allow most other particles to acquiremore » mass through the mechanism of electroweak symmetry breaking. We are members of the team in the CMS experiment that found evidence for the Higgs boson through its decay to two photons, the most sensitive channel at the LHC. We are proposing to carry out studies to determine whether the new particle has the properties expected for the standard model Higgs boson or whether it is something else. The new particle can still carry out its role in electroweak symmetry breaking but have other properties as well. Most theorists think that a single standard model Higgs boson cannot be the complete solution – there are other particles needed to answer some of the remaining questions, such as the hierarchy problem. The particle that has been observed could be one of several Higgs bosons, for example, or it could be composite. One model of physics beyond the standard model is supersymmetry, in which every ordinary particle has a superpartner with opposite spin properties. In supersymmetric models, there must be at least five Higgs bosons. In the most popular versions of supersymmetry, the lightest supersymmetric particle does not decay and is a candidate for dark matter. This proposal covers the period from June 1, 2013, to March 31, 2016. During this period the LHC will finally reach its design energy, almost twice the energy at which it now runs. We will be able to study the Higgs boson at the current LHC energy using about three times as much data as were used to make the observation. In 2013 the LHC will shut down to make preparations to run at its design energy in 2015. During the shutdown period, we will be preparing upgrades of the detector to be able to run at the higher rates of proton-proton collisions that will also be possible once the LHC is running at design energy. The upgrade on which we are working, the inner silicon pixel tracker, will be installed in late 2016. Definitive tests of whether the new particle satisfies the properties of the standard model Higgs boson will almost certainly require both the higher energy and the larger amounts of data that can be accumulated using the higher rates. Meanwhile we will use the data taken during 2012 and the higher energy data starting in 2015 to continue to search for beyond-the-standard-model physics such as supersymmetry and heavy neutrinos. We have already made such searches using data since the LHC started running. We are discussing with theorists how a 125-GeV Higgs modifies such models. Finding such particles will probably also require the higher energy and larger amounts of data beginning in 2015. The period of this proposal promises to be very exciting, leading to new knowledge of the matter in the Universe.« less
  • The Louisiana Tech University High Energy Physics group has developed a research program aimed at experimentally testing the Standard Model of particle physics and searching for new phenomena through a focused set of analyses in collaboration with the ATLAS experiment at the Large Hadron Collider (LHC) at the CERN laboratory in Geneva. This research program includes involvement in the current operation and maintenance of the ATLAS experiment and full involvement in Phase 1 and Phase 2 upgrades in preparation for future high luminosity (HL-LHC) operation of the LHC. Our focus is solely on the ATLAS experiment at the LHC, withmore » some related detector development and software efforts. We have established important service roles on ATLAS in five major areas: Triggers, especially jet triggers; Data Quality monitoring; grid computing; GPU applications for upgrades; and radiation testing for upgrades. Our physics research is focused on multijet measurements and top quark physics in final states containing tau leptons, which we propose to extend into related searches for new phenomena. Focusing on closely related topics in the jet and top analyses and coordinating these analyses in our group has led to high efficiency and increased visibility inside the ATLAS collaboration and beyond. Based on our work in the DØ experiment in Run II of the Fermilab Tevatron Collider, Louisiana Tech has developed a reputation as one of the leading institutions pursuing jet physics studies. Currently we are applying this expertise to the ATLAS experiment, with several multijet analyses in progress.« less
  • AB 1558 creates a 55% state tax credit up to $3,000 for installation of solar systems that produce heat, cool, or electricity. Conservation measures applied in conjunction with such solar systems, which reduce the first cost or increase the energy savings of such systems, may also be eligible for the tax credit. The ERCDC is directed by this legislation to develop solar-system eligibility criteria for the tax credit. The immediate concern of the Conservation Division has been to investigate the feasibility of developing simplified rules of thumb that could be applied in conjunction with the solar-system eligibility criteria currently beingmore » developed by the energy commission. Ideal rules of thumb are listed. Accordingly, the Conservation Division of ERCDC recently entered into an agreement with Atlas Corporation to analyze the trade-offs between: reducing thermal loads through retrofitting various conservation measures and supplying those loads (domestic space and hot water) with active solar technology. The November 30, 1977 report entitled ''Energy Savings Resulting from Incremental Insulation and Incremental Solar System Capacity Preliminary Report'' was circulated to the public and has received several helpful criticisms and questions relating to the scope of the analysis and interpretation of its findings. This discussion is directed towards clarifying these concerns. (MCW)« less
  • Documenting past climates and their associated terrestrial ecosystems is one means of predicting how modern landscapes may respond to changing atmospheric composition resulting from the addition of greenhouse gases. Fossil pollen preserved in lake and bog sediments is an especially valuable source of paleoclimatic information. Initially, pollen records were used only as qualitative estimates of climate change, but more recent analyses indicate they can provide accurate quantitative reconstructions. The floristic simplicity of tundra and boreal forest and the coarse taxonomic resolution of northern pollen taxa were believed to seriously limit the use of pollen for interpreting high latitude paleoclimates. However,more » current studies in Alaska and Canada demonstrate that pollen data are relatively strong and sensitive climate indicators. The status of paleoclimate reconstructions based on pollen records from northern North America is discussed using isopoll maps, response surfaces, analogs, and percentage diagrams.« less