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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Functional prescription for EFT matching

We simplify the one-loop functional matching formalism to develop a streamlined prescription. The functional approach is conceptually appealing: all calculations are performed within the UV theory at the matching scale, and no prior determination of an Effective Field Theory (EFT) operator basis is required. Our prescription accommodates any relativistic UV theory that contains generic interactions (including derivative couplings) among scalar, fermion, and vector fields. As an example application, we match the singlet scalar extended Standard Model (SM) onto SMEFT.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Flattening of the EFT-hedron: supersymmetric positivity bounds and the search for string theory

We examine universal positivity constraints on 2 → 2 scattering in 4d planar N = 4 supersymmetric Yang-Mills theory with higher-derivative corrections. We present numerical evidence that the convex region of allowed Wilson coefficients (the “EFT-hedron”) flattens completely along about one-third of its dimensions when an increasing number of constraints on the spectral density from crossing-symmetry are included. Our analysis relies on the formulation of the positivity constraints as a linear optimization problem, which we implement using two numerical solvers, SDPB and CPLEX. Motivated by the flattening, we propose a novel partially resummed low-energy expansion of the 2 → 2 amplitude. As part of the analysis, we provide additional evidence in favor of the conjecture [1] that the Veneziano amplitude is the only amplitude compatible with both S-matrix bootstrap constraints and string monodromy.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2026

Probing the flavour structure of dimension-6 EFT operators in multilepton final states in proton-proton collisions at $\sqrt{s}=13$ TeV

An analysis of the flavour structure of dimension-6 effective field theory (EFT) operators in multilepton final states is presented, focusing on the interactions of quarks with Z bosons. For the first time, the flavour structure of these operators is disentangled by simultaneously probing the interactions with different quark generations. The analysis targets the associated production of a top quark pair and a Z boson, as well as diboson processes in final states with at least three leptons, which can be electrons or muons. The data were recorded by the CMS experiment in the years 2016–2018 in proton-proton collisions at a centre-of-mass energy of 13 TeV and correspond to an integrated luminosity of 138 fb −1 . Consistency with the standard model of particle physics is observed and limits are set on the selected Wilson coefficients, split into couplings to light- and heavy-quark generations.

Flavour Physics↗
DOE OSTI2024

Unleashing the power of EFT in neutrino-nucleus scattering

Neutrino physics is advancing into a precision era with the construction of new experiments, particularly in the few GeV energy range. Within this energy range, neutrinos exhibit diverse interactions with nucleons and nuclei. This study delves in particular into neutrino-nucleus quasi-elastic cross sections, taking into account both standard and, for the first time, non-standard interactions, all within the framework of effective field theory (EFT). The main uncertainties in these cross sections stem from uncertainties in the nucleon-level form factors, and from the approximations necessary to solve the nuclear many-body problem. We explore how these uncertainties influence the potential of neutrino experiments to probe new physics introduced by left-handed, right-handed, scalar, pseudoscalar, and tensor interactions. For some of these interactions the cross section is enhanced, making long-baseline experiments an excellent place to search for them. Our results, including tabulated cross sections for all interaction types and all neutrino flavors, can serve as the foundation for such searches.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

The bottom-up EFT: complete UV resonances of the SMEFT operators

The standard model effective field theory (SMEFT) provides systematic parameterization of all possible new physics above the electroweak scale. According to the amplitude-operator correspondence, an effective operator can be decomposed into a linear combination of several j-basis operators, which correspond to local amplitudes carrying certain spin and gauge quantum numbers in a particular scattering channel. Based on the Poincare and gauge symmetries of scattering amplitude, we construct the j-basis using the Casimir method for both the Lorentz and gauge sectors. The quantum numbers of the j-basis operators fix the quantum numbers of any intermediate state in the corresponding amplitudes, such as a UV resonance. This can be re-interpreted as the j-basis/UV correspondence, thus obtaining the j-bases in all partitions of fields for an operator amounts to finding all of its UV origins at tree level, constituting the central part of the bottom-up EFT framework. Applying the j-basis analysis to SMEFT, we obtain a complete list of possible tree-level UV origins of the effective operators at the dimension 5, 6, 7, and all the bosonic operators at dimension 8.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Measurement of the inclusive and differential $t\overline{t}γ$ cross sections in the single-lepton channel and EFT interpretation at $\sqrt{s}$ = 13 TeV

The production cross section of a top quark pair in association with a photon is measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The data set, corresponding to an integrated luminosity of 137 fb -1 , was recorded by the CMS experiment during the 2016–2018 data taking of the LHC. The measurements are performed in a fiducial volume defined at the particle level. Events with an isolated, highly energetic lepton, at least three jets from the hadronization of quarks, among which at least one is b tagged, and one isolated photon are selected. The inclusive fiducial $t\overline{t}γ$ cross section, for a photon with transverse momentum greater than 20 GeV and pseudorapidity |η| < 1.4442, is measured to be 798 ± 7(stat) ± 48(syst) fb, in good agreement with the prediction from the standard model at next-to-leading order in quantum chromodynamics. The differential cross sections are also measured as a function of several kinematic observables and interpreted in the framework of the standard model effective field theory (EFT), leading to the most stringent direct limits to date on anomalous electromagnetic dipole moment interactions of the top quark and the photon.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Nucleon polarizabilities and {Delta}-resonance magnetic moment in chiral EFT

Recent chiral EFT calculations of nucleon polarizabilities reveal a problem in the current empirical determination of proton's electromagnetic polarizabilities. We also report on the progress in the empirical determination of the {Delta}(1232)-resonance magnetic moment in the process of {gamma}p{yields}p{pi}{sup 0}{gamma}' measured at MAMI.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Toward electroweak scale cold dark matter with local dark gauge symmetry and beyond the DM EFT

In this talk, I describe a class of electroweak (EW) scale dark matter (DM) models where its stability or longevity are the results of underlying dark gauge symmetries: stable due to unbroken local dark gauge symmetry or topology, or long-lived due to the accidental global symmetry of dark gauge theories. Compared with the usual phenomenological dark matter models (including DM EFT or simplified DM models), DM models with local dark gauge symmetries include dark gauge bosons, dark Higgs bosons and sometimes excited dark matter. And dynamics among these fields are completely fixed by local gauge principle. The idea of singlet portals including the Higgs portal can thermalize these hidden sector dark matter very efficiently, so that these DM could be easily thermal DM. I also discuss the limitation of the usual DM effective field theory or simplified DM models without the full SM gauge symmetry, and emphasize the importance of the full SM gauge symmetry and renormalizability especially for collider searches for DM.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

ISO(4,1) symmetry in the EFT of inflation

In DBI inflation the cubic action is a particular linear combination of the two, otherwise independent, cubic operators π-dot {sup 3} and π-dot (∂{sub i}π){sup 2}. We show that in the Effective Field Theory (EFT) of inflation this is a consequence of an approximate 5D Poincar and apos;e symmetry, ISO(4,1), non-linearly realized by the Goldstone π. This symmetry uniquely fixes, at lowest order in derivatives, all correlation functions in terms of the speed of sound c{sub s}. In the limit c{sub s} → 1, the ISO(4,1) symmetry reduces to the Galilean symmetry acting on π. On the other hand, we point out that the non-linear realization of SO(4,2), the isometry group of 5D AdS space, does not fix the cubic action in terms of c{sub s}.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

Equivalence of EFTs and timelike extra dimensions

A flat 3-brane probing a five-dimensional anti–de Sitter space has the same symmetries and symmetry breaking pattern as one probing a five-dimensional de Sitter space with two time directions. Despite the seemingly different physical setups, we show that the effective field theory of the brane bending mode is identical in both cases. In particular, despite “wrong” signs in the Dirac-Born-Infeld (DBI) action for the two-time de Sitter case, the theories have the same S -matrix. This is consistent with the expectation that effective field theories are determined solely by their degrees of freedom and pattern of symmetry breaking, even in the case of spacetime symmetries. We comment further on the equivalence between the Weyl/dilaton and DBI representations of the EFT of broken conformal symmetry. Published by the American Physical Society 2024

Astronomy & Astrophysics↗
DOE OSTI2021

STrEAMlining EFT Matching

This paper presents STrEAM (SuperTrace Evaluation Automated for Matching), a Mathematica package that calculates all functional supertraces which arise when matching a generic UV model onto a relativistic Effective Field Theory (EFT) at one loop and to arbitrary order in the heavy mass expansion. STrEAM implements the covariant derivative expansion to automate the most tedious step of the streamlined functional matching prescription presented in Ref. [1]. The code and an example notebook are available at this link.

43 PARTICLE ACCELERATORS↗
NASA NTRS2009

EFTS Command Controller

A detailed description of an EFTS command controller and its functionality is presented. Prototype capability and NASA Dryden's Initial Operating Capability (IOC) is also described.

Arce, Dennis↗
NASA NTRS2009

Advanced Command Destruct System (ACDS) Enhanced Flight Termination System (EFTS)

NASA Dryden started working towards a single vehicle enhanced flight termination system (EFTS) in January 2008. NASA and AFFTC combined their efforts to work towards final operating capability for multiple vehicle and multiple missions simultaneously, to be completed by the end of 2011. Initially, the system was developed to support one vehicle and one frequency per mission for unmanned aerial vehicles (UAVs) at NASA Dryden. By May 2008 95% of design and hardware builds were completed, however, NASA Dryden's change of software safety scope and requirements caused delays after May 2008. This presentation reviews the initial and final operating capabilities for the Advanced Command Destruct System (ACDS), including command controller and configuration software development. A requirements summary is also provided.

Tow, David↗
NASA NTRS2016

EFT-1 Heatshield Aerothermal Environment Reconstruction

The EFT-1 Avcoat heatshield was instrumented with 34 plugs containing multiple thermocouples in-depth with an objective being to measure the flight aerothermal environment. This paper presents a discussion of the instrumentation and the techniques used to reconstruct the heating environment from the measured in-depth temperatures. The inverse heat transfer problem algorithms, models and assumptions will be outlined, and available results will be presented.

Oliver, A. Brandon↗
NASA NTRS2016

Comparisons Between Pretest Prediction and Flight Test Data of Aerodynamic Loading for EFT-1

Exploration Flight Test One (EFT-1) was an incredible milestone in the development NASA's Orion spacecraft. It incorporated hundreds of articles of flight test instrumentation and returned with a wealth of data. Aerodynamic surface pressures were collected during launch vehicle ascent and capsule reentry and descent. These discrete surface pressure measurements enable comparisons to computational results and ground test data. This paper details the comparisons between pre-test predictions and flight test data for the Orion MPCV Crew Module (CM) and Launch Abort Tower (LAT) during all phases of flight. Regions with strong comparisons, poor predictions, and lessons learned are discussed. 38 pressure measurements were made on the LAT during ascent. Nine of the gauges were Honeywell PPTs and the remainder were Kulite pressure transducers. In order to address bias in the Kulites, a two-point linear calibration was used and the details are discussed. Results from the flight are compared to existing database products. 44 pressure measurements were made on the CM during reentry and descent. Nine of the gauges were Honeywell PPTs and the remainder were Kulite pressure transducers. In order to address bias in the Kulites, a tare was made against the vacuum measurements as described below. Once the bias was removed from the gauges, comparisons between predicted loading and the measured results are compared.

Schwing, Alan M.↗
NASA NTRS2016

Remote Imaging of Exploration Flight Test-1 (EFT-1) Entry Heating Risk Reduction

A Measure of Performance (MOP) identified with an Exploration Flight Test-1 (EFT-1) Multi- Purpose Crew Vehicle (MPCV) Program Flight Test Objective (FTO) (OFT1.091) specified an observation during reentry though external ground-based or airborne assets with thermal detection capabilities. The objective of this FTO was to be met with onboard Developmental Flight Instrumentation (DFI), but the MOP for external observation was intended to provide complementary quantitative data and serve as a risk reduction in the event of anomalous DFI behavior (or failure). Mr. Gavin Mendeck, the Entry, Descent, and Landing (EDL) Phase Engineer for the MPCV Program (Vehicle Integration Office/Systems & Mission Integration) requested a risk-reduction assessment from the NASA Engineering and Safety Center (NESC) to determine whether quantitative imagery could be obtained from remote aerial assets to support the external observation MOP. If so, then a viable path forward was to be determined, risks identified, and an observation pursued. If not, then the MOP for external observation was to be eliminated.

Schuster, David M.↗
NASA NTRS2016

Processing Near-Infrared Imagery of the Orion Heatshield During EFT-1 Hypersonic Reentry

The Scientifically Calibrated In-Flight Imagery (SCIFLI) team captured high-resolution, calibrated, near-infrared imagery of the Orion capsule during atmospheric reentry of the EFT-1 mission. A US Navy NP-3D aircraft equipped with a multi-band optical sensor package, referred to as Cast Glance, acquired imagery of the Orion capsule's heatshield during a period when Orion was slowing from approximately Mach 10 to Mach 7. The line-of-sight distance ranged from approximately 65 to 40 nmi. Global surface temperatures of the capsule's thermal heatshield derived from the near-infrared intensity measurements complemented the in-depth (embedded) thermocouple measurements. Moreover, these derived surface temperatures are essential to the assessment of the thermocouples' reliance on inverse heat transfer methods and material response codes to infer the surface temperature from the in-depth measurements. The paper describes the image processing challenges associated with a manually-tracked, high-angular rate air-to-air observation. Issues included management of significant frame-to-frame motions due to both tracking jerk and jitter as well as distortions due to atmospheric effects. Corrections for changing sky backgrounds (including some cirrus clouds), atmospheric attenuation, and target orientations and ranges also had to be made. The image processing goal is to reduce the detrimental effects due to motion (both sensor and capsule), vibration (jitter), and atmospherics for image quality improvement, without compromising the quantitative integrity of the data, especially local intensity (temperature) variations. The paper will detail the approach of selecting and utilizing only the highest quality images, registering several co-temporal image frames to a single image frame to the extent frame-to-frame distortions would allow, and then co-adding the registered frames to improve image quality and reduce noise. Using preflight calibration data, the registered and averaged infrared intensity images were converted to surface temperatures on the Orion capsule's heatshield. Temperature uncertainties will be discussed relative to uncertainties of surface emissivity and atmospheric transmission loss. Comparison of limited onboard surface thermocouple data to the image derived surface temperature will be presented.

Spisz, Thomas S.↗