Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 10 of 10

Full-Text Articles in Physics

Gwtc-1: A Gravitational-Wave Transient Catalog Of Compact Binary Mergers Observed By Ligo And Virgo During The First And Second Observing Runs, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Sep 2019

Gwtc-1: A Gravitational-Wave Transient Catalog Of Compact Binary Mergers Observed By Ligo And Virgo During The First And Second Observing Runs, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We present the results from three gravitational-wave searches for coalescing compact binaries with component masses above 1 Ma™ during the first and second observing runs of the advanced gravitational-wave detector network. During the first observing run (O1), from September 12, 2015 to January 19, 2016, gravitational waves from three binary black hole mergers were detected. The second observing run (O2), which ran from November 30, 2016 to August 25, 2017, saw the first detection of gravitational waves from a binary neutron star inspiral, in addition to the observation of gravitational waves from a total of seven binary black hole mergers, …


First Search For Nontensorial Gravitational Waves From Known Pulsars, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Jan 2018

First Search For Nontensorial Gravitational Waves From Known Pulsars, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper …


Upper Limits On The Stochastic Gravitational-Wave Background From Advanced Ligo's First Observing Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Mar 2017

Upper Limits On The Stochastic Gravitational-Wave Background From Advanced Ligo's First Observing Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

A wide variety of astrophysical and cosmological sources are expected to contribute to a stochastic gravitational-wave background. Following the observations of GW150914 and GW151226, the rate and mass of coalescing binary black holes appear to be greater than many previous expectations. As a result, the stochastic background from unresolved compact binary coalescences is expected to be particularly loud. We perform a search for the isotropic stochastic gravitational-wave background using data from Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. The data display no evidence of a stochastic gravitational-wave signal. We constrain the dimensionless energy density of gravitational waves …


Constraints On Cosmic Strings From The Ligo-Virgo Gravitational-Wave Detectors, J. Aasi, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Apr 2014

Constraints On Cosmic Strings From The Ligo-Virgo Gravitational-Wave Detectors, J. Aasi, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs …


Search For Neutral Minimal Supersymmetric Standard Model Higgs Bosons Decaying To Tau Pairs In Pp Collisions At √S = 7 Tev, S. A. Chatrchyan, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, H Kalakhety, Robert M. Ralich, Igor Vodopiyanov, B. Dorney, S. Guragain Jun 2011

Search For Neutral Minimal Supersymmetric Standard Model Higgs Bosons Decaying To Tau Pairs In Pp Collisions At √S = 7 Tev, S. A. Chatrchyan, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, H Kalakhety, Robert M. Ralich, Igor Vodopiyanov, B. Dorney, S. Guragain

Aerospace, Physics, and Space Science Faculty Publications

A search for neutral minimal supersymmetric standard model (MSSM) Higgs bosons in pp collisions at the LHC at a center-of-mass energy of 7 TeV is presented. The results are based on a data sample corresponding to an integrated luminosity of 36 pb 1 recorded by the CMS experiment. The search uses decays of the Higgs bosons to tau pairs. No excess is observed in the tau-pair invariant-mass spectrum. The resulting upper limits on the Higgs boson production cross section times branching fraction to tau pairs, as a function of the pseudoscalar Higgs boson mass, yield stringent new bounds in the …


Search For Supersymmetry In Pp Collisions At √S = 7 Tev In Events With Two Photons And Missing Transverse Energy, S. A. Chatrchyan, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, H Kalakhety, Robert M. Ralich, Igor Vodopiyanov, B. Dorney, S. Guragain May 2011

Search For Supersymmetry In Pp Collisions At √S = 7 Tev In Events With Two Photons And Missing Transverse Energy, S. A. Chatrchyan, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, H Kalakhety, Robert M. Ralich, Igor Vodopiyanov, B. Dorney, S. Guragain

Aerospace, Physics, and Space Science Faculty Publications

A search for supersymmetry in the context of general gauge-mediated breaking with the lightest neutralino as the next-to-lightest supersymmetric particle and the gravitino as the lightest is presented. The data sample corresponds to an integrated luminosity of 36 pb 1 recorded by the CMS experiment at the LHC. The search is performed by using events containing two or more isolated photons, at least one hadronic jet, and significant missing transverse energy. No excess of events at high missing transverse energy is observed. Upper limits on the signal cross section for general gauge-mediated supersymmetry between 0.3 and 1.1 pb at the …


Search For Pair Production Of Second-Generation Scalar Leptoquarks In Pp Collisions At √S= 7 Tev, V. Khachatryan, A. M. Sirunyan, Thomas Bergauer, Marc M. Baarmand, Marcus Hohlmann, H Kalakhety, Robert M. Ralich, Igor Vodopiyanov, B. Dorney, S. Guragain May 2011

Search For Pair Production Of Second-Generation Scalar Leptoquarks In Pp Collisions At √S= 7 Tev, V. Khachatryan, A. M. Sirunyan, Thomas Bergauer, Marc M. Baarmand, Marcus Hohlmann, H Kalakhety, Robert M. Ralich, Igor Vodopiyanov, B. Dorney, S. Guragain

Aerospace, Physics, and Space Science Faculty Publications

A search for pair production of second-generation scalar leptoquarks in the final state with two muons and two jets is performed using proton-proton collision data at ffiffi s p ¼ 7 TeV collected by the CMS detector at the LHC. The data sample used corresponds to an integrated luminosity of 34 pb 1. The number of observed events is in good agreement with the predictions from the standard model processes. An upper limit is set on the second-generation leptoquark cross section times 2 as a function of the leptoquark mass, and leptoquarks with masses below 394 GeV are excluded at …


Search For Pair Production Of Second-Generation Scalar Leptoquarks In Pp Collisions At √S = 7 Tev, V. Khachatryan, A. M. Sirunyan, Thomas Bergauer, Marc M. Baarmand, Marcus Hohlmann, H Kalakhety, Robert M. Ralich, Igor Vodopiyanov, B. Dorney, S. Guragain May 2011

Search For Pair Production Of Second-Generation Scalar Leptoquarks In Pp Collisions At √S = 7 Tev, V. Khachatryan, A. M. Sirunyan, Thomas Bergauer, Marc M. Baarmand, Marcus Hohlmann, H Kalakhety, Robert M. Ralich, Igor Vodopiyanov, B. Dorney, S. Guragain

Aerospace, Physics, and Space Science Faculty Publications

A search for pair production of second-generation scalar leptoquarks in the final state with two muons and two jets is performed using proton-proton collision data at ffiffi s p ¼ 7 TeV collected by the CMS detector at the LHC. The data sample used corresponds to an integrated luminosity of 34 pb 1. The number of observed events is in good agreement with the predictions from the standard model processes. An upper limit is set on the second-generation leptoquark cross section times 2 as a function of the leptoquark mass, and leptoquarks with masses below 394 GeV are excluded at …


All-Sky Ligo Search For Periodic Gravitational Waves In The Early Fifth-Science-Run Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Mar 2009

All-Sky Ligo Search For Periodic Gravitational Waves In The Early Fifth-Science-Run Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100Hz and with the frequency's time derivative in the range -5x10-9-0Hzs-1. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10-24 are obtained over a …


Upper Limits To The Nightside Ionosphere Of Mars, Jane L. Fox Jul 1993

Upper Limits To The Nightside Ionosphere Of Mars, Jane L. Fox

Physics Faculty Publications

The nightside ionosphere of Mars could be produced by electron precipitation or by plasma transport from the dayside, by analogy to the Venus, but few measurements are available. We report here model calculations of upper limits to the nightside ion densities on Mars that would be produced by both mechanisms. For the auroral model, we have adopted the downward traveling portions of the electron spectra measured by the HARP instrument on the Soviet Phobos spacecraft in the Martian plasma sheet and in the magnetotail lobes. For the plasma transport case, we have imposed on a model of the nightside thermosphere, …