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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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DOE OSTI2014

Symmetry Breaking, Unification, and Theories Beyond the Standard Model

A model was constructed in which the supersymmetric fine-tuning problem is solved without extending the Higgs sector at the weak scale. We have demonstrated that the model can avoid all the phenomenological constraints, while avoiding excessive fine-tuning. We have also studied implications of the model on dark matter physics and collider physics. I have proposed in an extremely simple construction for models of gauge mediation. We found that the {mu} problem can be simply and elegantly solved in a class of models where the Higgs fields couple directly to the supersymmetry breaking sector. We proposed a new way of addressing the flavor problem of supersymmetric theories. We have proposed a new framework of constructing theories of grand unification. We constructed a simple and elegant model of dark matter which explains excess flux of electrons/positrons. We constructed a model of dark energy in which evolving quintessence-type dark energy is naturally obtained. We studied if we can find evidence of the multiverse.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Classification without labels: learning from mixed samples in high energy physics

Modern machine learning techniques can be used to construct powerful models for difficult collider physics problems. In many applications, however, these models are trained on imperfect simulations due to a lack of truth-level information in the data, which risks the model learning artifacts of the simulation. In this paper, we introduce the paradigm of classification without labels (CWoLa) in which a classifier is trained to distinguish statistical mixtures of classes, which are common in collider physics. Crucially, neither individual labels nor class proportions are required, yet we prove that the optimal classifier in the CWoLa paradigm is also the optimal classifier in the traditional fully-supervised case where all label information is available. After demonstrating the power of this method in an analytical toy example, we consider a realistic benchmark for collider physics: distinguishing quark- versus gluon-initiated jets using mixed quark/gluon training samples. More generally, CWoLa can be applied to any classification problem where labels or class proportions are unknown or simulations are unreliable, but statistical mixtures of the classes are available.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Accelerators for Rare Processes and Physics Beyond Colliders: Report of the AF5 Topical Group to Snowmass 2021

This report summarizes the findings of the AF5 Topical Subgroup to Snowmass 2021, which investigated accelerators for rare processes and physics beyond colliders. The report focuses primarily on opportunities for dark sector searches and the need for coordinated development of the Fermilab experimental program for PIP-II and beyond. In addition, a number of other physics opportunities are cataloged and suggestions for synergistic R&D opportunities with various areas of technological development are discussed.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

A Muon Collider Facility for Physics Discovery

Muon colliders provide a unique route to deliver high energy collisions that enable discovery searches and precision measurements to extend our understanding of the fundamental laws of physics. The muon collider design aims to deliver physics reach at the highest energies with costs, power consumption and on a time scale that may prove favorable relative to other proposed facilities. In this context, a new international collaboration has formed to further extend the design concepts and performance studies of such a machine. This effort is focused on delivering the elements of a $\sim$10 TeV center of mass (CM) energy design to explore the physics energy frontier. The path to such a machine may pass through lower energy options. Currently a 3 TeV CM stage is considered. Other energy stages could also be explored, e.g. an s-channel Higgs Factory operating at 125 GeV CM. We describe the status of the R&D and design effort towards such a machine and lay out a plan to bring these concepts to maturity as a tool for the high energy physics community.

43 PARTICLE ACCELERATORS↗
DOE OSTI2012

Particle Physics in a Season of Change

A digest of the authors opening remarks at the 2011 Hadron Collider Physics Symposium. I have chosen my title to reflect the transitions we are living through, in particle physics overall and in hadron collider physics in particular. Data-taking has ended at the Tevatron, with {approx} 12 fb{sup -1} of {bar p}p interactions delivered to CDF and D0 at {radical}s = 1.96 TeV. The Large Hadron Collider has registered a spectacular first full-year run, with ATLAS and CMS seeing > 5 fb{sup -1}, LHCb recording {approx} 1 fb{sup -1}, and ALICE logging nearly 5 pb{sup -1} of pp data at {radical}s = 7 TeV, plus a healthy dose of Pb-Pb collisions. The transition to a new energy regime and new realms of instantaneous luminosity exceeding 3.5 x 10{sup 33} cm{sup -2} s{sup -1} has brought the advantage of enhanced physics reach and the challenge of pile-up reaching {approx} 15 interactions per beam crossing. I am happy to record that what the experiments have (not) found so far has roused some of my theoretical colleagues from years of complacency and stimulated them to think anew about what the TeV scale might hold. We theorists have had plenty of time to explore many proposals for electroweak symmetry breaking and for new physics that might lie beyond established knowledge. With so many different theoretical inventions in circulation, it is in the nature of things that most will be wrong. Keep in mind that we learn from what experiment tells us is not there, even if it is uncommon to throw a party for ruling something out. Some non-observations may be especially telling: the persistent absence of flavor-changing neutral currents, for example, seems to me more and more an important clue that we have not yet deciphered. It is natural that the search for the avatar of electroweak symmetry breaking preoccupies participants and spectators alike. But it is essential to conceive the physics opportunities before us in their full richness. I would advocate a three-fold approach: Explore, Search, Measure! The first phase of running at the LHC has brought us to two new lands - in proton-proton and lead-lead collisions - and we may well enter other new lands with each change of energy or increase of sensitivity. I believe that it will prove very rewarding to spend some time simply exploring each new landscape, without strong preconceptions, to learn what is there and, perhaps, to encounter interesting surprises. Directed searches, for which we have made extensive preparations, are of self-evident interest. Here the challenge will be to broaden the searches over time, so the searches are not too narrowly directed. Our very successful conception of particles and forces is highly idealized. We have a great opportunity to learn just how comprehensive is our network of understanding by making precise measurements and probing for weak spots, or finding more sweeping accord between theory and experiment.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

The physics of heavy quark distributions in hadrons: Collider tests

Here, we present a review of the current understanding of the heavy quark distributions in the nucleon and their impact on collider physics. The origin of strange, charm and bottom quark pairs at high light-front (LF) momentum fractions in hadron wavefunction—the “intrinsic” quarks, is reviewed. The determination of heavy-quark parton distribution functions (PDFs) is particularly significant for the analysis of hard processes at LHC energies. We show that a careful study of the inclusive production of open charm and the production of γ/Z/W particles, accompanied by the heavy jets at large transverse momenta can give essential information on the intrinsic heavy quark (IQ) distributions. We also focus on the theoretical predictions concerning other observables which are very sensitive to the intrinsic charm contribution to PDFs including Higgs production at high x F and novel fixed target measurements which can be tested at the LHC.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Center for Theoretical Underground Physics and Related Fields. CETUP2015/ Particle Physics and Cosmology Conference. PPC2015)

For last five years Center for Theoretical Underground Physics and Related Areas (CETUP*) serves as a collaboration point for scientists from around the world interested in theoretical and experimental aspects of underground science. The mission of CETUP* is to promote an organized research in physics, astrophysics, geoscience, geomicrobiology and other fields related to the underground science and provide a stimulating environment for creative thinking and open communication between researches of varying ages and nationalities in dynamic atmosphere of intense scientific interactions. Scientists invited to participate in the program will not only provide theoretical support to the underground science, but they will also examine core questions of the 21st century including: What is dark matter? How well do we know the neutrino parameters?, How have neutrinos shaped the evolution of the universe?, How were the heavy elements made?, What are the fundamental underlying symmetries of the Universe? Is there a Grand Unified Theory of the Universe? How do supernovae explode? Studies of Neutrino Physics and Dark Matter are of high interest to particle and nuclear physicists, astrophysicists and cosmologists. Ongoing and proposed Neutrino and Dark Matter experiments are expected to unveil the answers to fundamental questions about the Universe. This year summer program was focused exactly on these subjects bringing together experts in dark matter, neutrino physics, particle physics, nuclear physics and astrophysics and cosmology. CETUP*2015 consisted of 5 week long program (June 14 – July 18, 2015) covering various theoretical and experimental aspects in these research areas. The two week long session on Dark Matter physics (June 14 – June 26) was followed by two week long program on Neutrino physics (July 6 – July 18). The international conference entitled IXth International Conference on Interconnection Between Particle Physics and Cosmology (PPC) was hosted at CETUP* in the time between the Dark Matter and Neutrino workshops (June 29 – July 3) covering the subjects of dark matter, dark energy, neutrino physics, gravitational waves, collider physics and many others. PPC brought about 90 national and international participants. Started at Texas A&M University in 2007, PPC travelled to many places which include Geneva (Switzerland), Turin (Italy), Seoul (South Korea) and Leon (Mexico) over last few years. The objectives of CETUP*2015 and PPC2015 were to analyze the connection between dark matter and particle physics models, discuss the connections among dark matter, grand unification models and recent neutrino results and predictions for possible experiments.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Center for Theoretical Underground Physics and Related Areas - CETUP*2013 Summer Program

In response to an increasing interest in experiments conducted at deep underground facilities around the world, in 2010 the theory community has proposed a new initiative - a Center for Theoretical Underground Physics and Related Areas (CETUP*). The main goal of CETUP* is to bring together people with different talents and skills to address the most exciting questions in particle and nuclear physics, astrophysics, geosciences, and geomicrobiology. Scientists invited to participate in the program do not only provide theoretical support to the underground science, they also examine underlying universal questions of the 21 st century including: What is dark matter?, What are the masses of neutrinos?, How have neutrinos shaped the evolution of the universe?, How were the elements from iron to uranium made?, What is the origin and thermal history of the Earth? The mission of the CETUP* is to promote an organized research in physics, astrophysics, geoscience, geomicrobiology and other fields related to the underground science via individual and collaborative research in dynamic atmosphere of intense scientific interactions. Our main goal is to bring together scientists scattered around the world, promote the deep underground science and provide a stimulating environment for creative thinking and open communication between researches of varying ages and nationalities. CETUP*2014 included 5 week long program (June 24 – July 26, 2013) covering various theoretical and experimental aspects of Dark Matter, Neutrino Physics and Astrophysics. Two week long session focused on Dark Matter (June 24-July 6) was followed by two week long program on Neutrino Physics and Astrophysics (July 15-26). The VII th International Conference on Interconnections between Particle Physics and Cosmology (PPC) was sandwiched between these sessions (July 8-13) covering the subjects of dark matter, neutrino physics, gravitational waves, collider physics and other from both theoretical end experimental aspects. PPC was initiated at Texas A&M University in 2007 and travelled to many places which include Geneva, Turin, Seoul (S. Korea) etc. during the last 5 years before coming back to USA. The objectives of CETUP* and PPC were to analyze the connection between dark matter and particle physics models, discuss the connections among dark matter, grand unification models and recent neutrino results and predictions for possible experiments, develop a theoretical understanding of the three-neutrino oscillation parameters, provide a stimulating venue for exchange of scientific ideas among experts in neutrino physics and unification, connect with venues for public education outreach to communicate the importance of dark matter, neutrino research, and support of investment in science education, support mission of the Snowmass meeting and allow for extensive discussions of the ideas crucial for the future of high energy physics. The selected subjects represented the forefront of research topics in particle and nuclear physics, for example: recent precise measurements of all the neutrino mixing angles (that necessitate a theoretical roadmap for future experiments) or understanding of the nature of dark matter (that allows us to comprehend the composition of the cosmos better). All the covered topics are considered as a base for new physics beyond the Standard Model of particle physics.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2011

Electron Ion Collider transverse spin physics

Electron Ion Collider is a future high energy facility for studies of the structure of the nucleon. Three-dimensional parton structure is one of the main goals of EIC. In momentum space Transverse Momentum Dependent Distributions (TMDs) are the key ingredients to map such a structure. At leading twist spin structure of spin-1/2 hadron can be described by 8 TMDs. Experimentally these functions can be studied in polarised SIDIS experiments. We discuss Sivers distribution function that describes distribution of unpolarised quarks in a transversely polarised nucleon and transversity that measures distribution of transversely polarised quarks in a transversely polarised nucleon.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Subleading effects in QCD global fits

I discuss several corrections to leading twist calculation of nucleon structure functions which are needed to include experimental data at large parton fractional momentum x and at low scale Q{sup 2} in global fits of parton distribution functions. In particular I discuss the results of the CTEQ6X global fit, and some work in progress. Topics covered include the interplay of target mass and higher-twist corrections, the importance of nuclear corrections for deuterium target data, and applications to the study of quark-hadron duality. Implications for collider physics are highlighted.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

The CTEQ-JLab global analysis of large-x PDFs

I discuss several corrections to leading twist calculations of nucleon structure functions which are needed to include experimental data at large parton fractional momentum x and at low scales Q{sup 2} in global fits of parton distribution functions. In particular I discuss the results of the CTEQ-JLab global fit, and some work in progress. Topics covered include the interplay of target mass and higher-twist corrections, the importance of nuclear corrections for deuterium target data, and applications to the study of quark-hadron duality. Implications for collider physics are highlighted.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Next-to-leading power endpoint factorization and resummation for off-diagonal “gluon” thrust

The lack of convergence of the convolution integrals appearing in next-to-leading-power (NLP) factorization theorems prevents the applications of existing methods to resum power-suppressed large logarithmic corrections in collider physics. We consider thrust distribution in the two-jet region for the flavour-nonsinglet off-diagonal contribution, where a gluon-initiated jet recoils against a quark-antiquark pair, which is power-suppressed. With the help of operatorial endpoint factorization conditions, we obtain a factorization formula, where the individual terms are free from endpoint divergences in convolutions and can be expressed in terms of renormalized hard, soft and collinear functions in four dimensions. This allows us to perform the first resummation of the endpoint-divergent SCETI observables at the leading logarithmic accuracy using exclusively renormalization-group methods. The presented approach relies on universal properties of the soft and collinear limits and may serve as a paradigm for the systematic NLP resummation for other 1 → 2 and 2 → 1 collider physics processes.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

TMD Handbook

This handbook provides a comprehensive review of transverse-momentum-dependent parton distribution functions and fragmentation functions, commonly referred to as transverse momentum distributions (TMDs). TMDs describe the distribution of partons inside the proton and other hadrons with respect to both their longitudinal and transverse momenta. They provide unique insight into the internal momentum and spin structure of hadrons, and are a key ingredient in the description of many collider physics cross sections. Understanding TMDs requires a combination of theoretical techniques from quantum field theory, nonperturbative calculations using lattice QCD, and phenomenological analysis of experimental data. The handbook covers a wide range of topics, from theoretical foundations to experimental analyses, as well as recent developments and future directions. It is intended to provide an essential reference for researchers and graduate students interested in understanding the structure of hadrons and the dynamics of partons in high energy collisions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

High Energy Physics (Final Report)

The research at Yale funded by the DOE Office of High Energy Physics, with grant title Yale High Energy Physics Research is centered at all the frontier areas of elementary particle physics, both experimental and theoretical. Among the most compelling are the continued exciting study of the energy frontier at the LHC, the physics of neutrinos and neutrino mixing, and the properties of dark energy in the universe. These activities offer promise for providing the answers to some of the most fundamental questions in science, such as the origin of mass and the baryon asymmetry in the Universe, and the cause of its accelerated expansion. In neutrino physics Profs. Fleming and Heeger are leading several experiments using reactor and accelerator neutrinos and participate in research and development towards precision neutrino detection. In flavor physics, Prof. Demers contributes to the physics selection and design of the mu2e Experiment. In collider physics Profs. Baker, Demers, and Tipton’s efforts span searches and measurements for the Higgs, exotics, and planned upgrades. In astrophysics Profs. Baltay and Padmanabhan are exploring the Cosmic Frontier. Prof. Baltay plays a leading role in La Silla/QUEST and the Dark Energy Spectroscopic Survey (DESI). Prof. Padmanabhan uses large galaxy surveys to constrain dark energy through critical participation in the Baryon Oscillation Spectroscopic Survey (BOSS) and in DESI. In theoretical research, Prof. Goldberger has made contributions to many fields including electroweak symmetry breaking, relativistic and non-relativistic conformal field theories, cosmology and inflation, and general relativity. At Yale, we enjoy a close collaboration and shared resources between different experimental groups, and between theory and experimental communities.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Accelerator Physics of Colliders

This article provides background for the High-Energy Collider Parameter Tables that follow and some additional information; see in-depth review and a comprehensive list of references in [1]; citations below are limited to widely used textbooks and open access seminal papers and reviews.

43 PARTICLE ACCELERATORS↗
DOE OSTI2012

High Energy Physics at Tufts University Final Report

In this Final Report, we the researchers of the high energy physics group at Tufts University summarize our works and achievements in three frontier areas of elementary particle physics: (i) Neutrino physics at the Intensity Frontier, (ii) Collider physics at the Energy Frontier, and (iii) Theory investigations of spin structure and quark-gluon dynamics of nucleons using quantum chromodynamics. With our Neutrino research we completed, or else brought to a useful state, the following: Data-taking, physics simulations, physics analysis, physics reporting, explorations of matter effects, and detector component fabrication. We conducted our work as participants in the MINOS, NOvA, and LBNE neutrino oscillation experiments and in the MINERvA neutrino scattering experiment. With our Collider research we completed or else brought to a useful state: Data-taking, development of muon system geometry and tracking codes, software validation and maintenance, physics simulations, physics analysis, searches for new particles, and study of top-quark and B-quark systems. We conducted these activities as participants in the ATLAS proton-proton collider experiment at CERN and in the CDF proton-antiproton collider experiment at Fermilab. In our Theory research we developed QCD-based models, applications of spin phenomenology to fundamental systems, fitting of models to data, presenting and reporting of new concepts and formalisms. The overarching objectives of our research work have always been: 1) to test and clarify the predictions of the Standard Model of elementary particle physics, and 2) to discover new phenomena which may point the way to a more unified theoretical framework.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Theoretical Research in Weak-Electromagnetic and Strong Interactions (Final Report)

Project: Theoretical and Experimental Research in Weak, Electromagnetic and Strong Interactions: Investigators: S. Nandi, K.S. Babu, F. Rizatdinova Institution: Oklahoma State University, Stillwater, OK 74078. This completed project focused on the cutting edge research in theoretical and experimental high energy physics. In theoretical high energy physics, the two investigators (Nandi and Babu) worked on a variety of topics in model-building and phenomenological aspects of elementary particle physics. This includes unification of particles and forces, neutrino physics, Higgs boson physics, proton decay, supersymmetry, and collider physics. Novel physics ideas beyond the Standard Model with testable consequences at the LHC have been proposed. These ideas have stimulated the experimental community to look for new signals. The contributions of the experimental high energy physics group has been at the D0 experiment at the Fermilab Tevatraon and the ATLAS experiment at the Large Hadron Collider. At the D0 experiment, the main focus was search for the Higgs boson in the WH channel, where improved limits were obtained. At the LHC, the OSU group has made significant contributions to the top quark physics, and the calibration of the b-tagging algorithms. The group is also involved in the pixel detector upgrade. This DOE supported grant has resulted in 5 PhD degrees during the past three years. Three postdoctoral fellows were supported as well. In theoretical research over 40 refereed publications have resulted in the past three years, with several involving graduate students and postdoctoral fellows. It also resulted in over 30 conference presentations in the same time period. We are also involved in outreach activities through the Quarknet program, where we engage Oklahoma school teachers and students in our research.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗