Physical Sciences and Mathematics Commons^™

Jet Production And Rppb In Pp Collisions At Sqrt(S) = 8 Tev And P--Pb Collisions At Sqrt(Snn) = 8.16 Tev Using The Alice Detector, Austin Schmier

Doctoral Dissertations

At the CERN Large Hadron Collider, protons and heavy ions are collided at relativistic
speeds in order to study the behavior and processes of Quantum Chromodynamics (QCD). One such process is the production of collimated sprays of particles called jets resulting from the hard scattering of two partons. Jets are an important probe that provide a window into the early stages of the collision.

Measurements in small systems such as proton-proton (pp) and proton-lead (p–Pb)
collisions are important in order to provide constraints on nuclear parton distribution
functions and the strong coupling constant αS [55]. Measurements at different center of …

Jet Noise Reduction: A Fresh Start, Christopher K. Tam, Fang Q. Hu

Mathematics & Statistics Faculty Publications

Attempts to reduce jet noise began some 70 years ago. In the literature, there have been many publications written on this topic. By now, it is common knowledge that jet noise consists of a number of components. They possess different spectral and radiation characteristics and are generated by different mechanisms. It appears then that one may aim at the suppression of the noise of a single component instead of trying to reduce jet noise overall. The objective of the present project is to reduce large turbulence structures noise. It is the most dominant noise component radiating in the downstream direction. …

Realistic Binary Neutron Stars Collisions Simulations: Challenges And Opportunities, Maria Babiuc-Hamilton

Physics Faculty Research

Since 2015, when the LIGO-Virgo collaboration announced the first simultaneous detections of gravitational waves (GW150914) until now, more than 66 gravitational wave detections were reported, but only two signals came from a binary neutron star collision, the GW170817 and GW190425 events. GW170817 was accompanied by an electromagnetic outburst manifested as a kilonova and an off-axis jet. However, no conclusive electromagnetic signature was found to come from the GW190425. Indeed, nature proves again more complicated than our models, and it is still a big question how to model kilonovae, or to understand the mechanisms driving astrophysical jets and gamma ray bursts. …

A Novel Method For Computations Of Ratios Of Jet Cross Sections In Perturbative Quantum Chromodynamics, Connor Waits

Mathematics Senior Capstone Papers

The strong interaction is the force responsible for binding quarks to form hadrons, such as protons and neutrons, and also for binding protons and neutrons to form the nuclei of atoms. The properties of the strong interaction can be studied in particle collisions from measurements of the production rates of collimated sprays of particles, called jets. In particular, the ratio of the number of collisions that produce three jets over the number of collisions that produce two jets is a direct measure of the strength of the strong interaction. This strength is quantified by the strong coupling constant, αs. Determinations …

Fr0 Radio Galaxies And Their Place In The Radio Morphology Classification, David Garofalo, Chandra B. Singh

Faculty and Research Publications

So-called FR0 radio galaxies have recently emerged as a family of active galaxies with all the same properties as FRI radio galaxies except for their ratio of core to total emission, which is about 30 times higher than that of FRI sources. We show how their properties fit within the gap paradigm as low, prograde, spinning black holes whose progenitors are powerful FRII quasars that transitioned rapidly from the cold mode into advection-dominated accretion over a few million years. The prediction is that if sufficient fuel exists, FR0 radio galaxies will evolve into full-fledged FRI radio galaxies and the observational …

Jet Geometry Engineering Via Di-Jet Imbalance Measurements At Rhic In Star, Nicholas Elsey

Wayne State University Dissertations

Ultra-relativistic heavy ion collisions produced at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) produce a new state of matter of deconfined quarks and gluons (partons) called the quark-gluon plasma (QGP). This plasma of deconfined but strongly coupled partons is believed to have been the primary state of matter in the universe up to a few milliseconds after the Big Bang. High energy partons produced in hard scatterings early in the collision can be used to probe the entire lifetime of the QGP. These partons propagate through and interact with the QGP before fragmenting into collimated …

Top Tagging: An Analytical Perspective, Mrinal Dasgupta, Marco Guzzi, Jacob Rowling, Gregory Soyez

Faculty and Research Publications

In this paper we study aspects of top tagging from first principles of QCD. We find that the method known as the CMS top tagger becomes collinear unsafe at high pt and propose variants thereof which are IRC safe, and hence suitable for analytical studies, while giving a comparable performance to the CMS tagger. We also develop new techniques to identify three-pronged jet substructure, based on adaptations of the Y-splitter method and its combination with grooming. A novel feature of our studies, relative to previous calculations of two-pronged substructure, is our use of triple-collinear splitting functions combined with all-order resummation, …

Heavy Flavour In Jets And Azimuthal Correlations, Patrick J. Steffanic

Physics

We studied heavy-flavor azimuthal correlations using the semi-leptonic decay channel of hard-scattered bottom quarks in proton-proton collisions at center-of-mass energies of 7 TeV. We used a mixed-event method to produce a corrected correlation that hinted at back-to-back pair production. We further studied the jets resulting from these heavy-flavor hard scatterings, and jets resulting from light-flavor and gluon scattering. We compared several kinematic variables from each of the jet populations, concluding that novel kinematic variables must be developed in order to effectively separate the jet populations.

Cross Section Predictions Of The Z Boson In Association With Jets At 14 Tevcenter-Of-Mass Energy In Proton?Proton Collisions, Kamuran Di̇lsi̇z, Emrah Tiraş

Turkish Journal of Physics

QCD predictions of the Z (Z → l+l) boson in association with jets (up to 2 jets) in proton?proton collisions are presented in this study. The results are predicted at LO and NLO accuracy using two most recent parton distribution functions, CT14 and MMHT2014. LO and NLO corrections are obtained with LO, NLO, and NNLO PDFs to find out the best PDF, which provides well compatible predictions with the experimental measurements. QCD predictions are performed at 13 and 14 TeV center-of-mass energies. To verify the obtained results, the predictions are compared with the measured results by ATLAS collaboration. NLO QCD …

Correlation Between Emission Lines And Radio Luminosities Of Active Galactic Nuclei, Jessica Short-Long

Theses and Dissertations--Physics and Astronomy

Radio-loud active galactic nuclei (AGN) are one class of objects associated with accretion activity onto supermassive black holes in centers of massive galaxies. They are believed to be in a radiatively-inefficient accretion mode with low accretion rate. To understand this accretion mode, it is important to measure its radiative output at high energies (> 13.6eV), which can be traced through optical emission lines. However, little is known about their true radiative output. This is because no correlation between optical emission-line and radio luminosity has been found for the majority of low-luminosity radio AGN, which are often classified as low-excitation radio …

Measurements Of Differential Cross Sections For Associated Production Of A W Boson And Jets In Proton-Proton Collisions At Square Root Of S = 8 Tev, A. M. Sirunyan, A. R. Tumasyan, W. Adam, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, Daniel Noonan, Tuhin S. Roy, Francisco X. Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

A measurement of the differential cross sections for a W boson produced in association with jets in the muon decay channel is presented. The measurement is based on 13 TeV proton-proton collision data corresponding to an integrated luminosity of 2.2 fb-1, recorded by the CMS detector at the LHC. The cross sections are reported as functions of jet multiplicity, jet transverse momentum pT, jet rapidity, the scalar pT sum of the jets, and angular correlations between the muon and each jet for different jet multiplicities. The measured cross sections are in agreement with predictions that include multileg leading-order (LO) and …

Sma Observations Of The Hot Molecular Core Iras 18566+0408, Andrea Silva, Qizhou Zhang, Patricio Sanhueza, Xing Lu, Maria T. Beltran, Cassandra Fallscheer, Henrik Beuther, T. K. Sridharan, Riccardo Cesaroni

All Faculty Scholarship for the College of the Sciences

We present Submillimeter Array (SMA) observations toward the high-mass star-forming region IRAS 18566+0408. Observations at the 1.3 mm continuum and in several molecular line transitions were performed in the compact (2ʺ4 angular resolution) and very-extended (~0ʺ4 angular resolution) configurations. The continuum emission from the compact configuration shows a dust core of 150 M _⊙, while the very-extended configuration reveals a dense (2.6 × 10⁷ cm⁻³) and compact (~4000 au) condensation of 8 M _⊙. We detect 31 molecular transitions from 14 species including CO isotopologues, SO, CH₃OH, OCS, and CH₃CN. Using …

Magnetic Fields Threading Black Holes: Restrictions From General Relativity And Implications For Astrophysical Black Holes, David Garofalo

Faculty and Research Publications

The idea that black hole spin is instrumental in the generation of powerful jets in active galactic nuclei and X-ray binaries is arguably the most contentious claim in black hole astrophysics. Because jets are thought to originate in the context of electromagnetism, and the modeling of Maxwell fields in curved spacetime around black holes is challenging, various approximations are made in numerical simulations that fall under the guise of ‘ideal magnetohydrodynamics’. But the simplifications of this framework may struggle to capture relevant details of real astrophysical environments near black holes. In this work, we highlight tension between analytic and numerical …

Measurement And Qcd Analysis Of Double-Differential Inclusive Jet Cross Sections In Pp Collisions At √S=8 Tev And Cross Section Ratios To 2.76 And 7 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A measurement of the double-differential inclusive jet cross section as a function of the jet transverse momentum pT and the absolute jet rapidity |y| is presented. Data from LHC proton-proton collisions at s=8 TeV, corresponding to an integrated luminosity of 19.7 fb−1, have been collected with the CMS detector. Jets are reconstructed using the anti-kT clustering algorithm with a size parameter of 0.7 in a phase space region covering jet pT from 74 GeV up to 2.5 TeV and jet absolute rapidity up to |y| = 3.0. The low-pT jet range between 21 and 74 GeV is also studied up …

Search For Top Squark Pair Production In Compressed-Mass-Spectrum Scenarios In Proton-Proton Collisions At S=8 Tev Using The Αt Variable, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

An inclusive search is performed for supersymmetry in final states containing jets and an apparent imbalance in transverse momentum, p→T miss, due to the production of unobserved weakly interacting particles in pp collisions at a centre-of-mass energy of 8 TeV. The data, recorded with the CMS detector at the CERN LHC, correspond to an integrated luminosity of 18.5 fb−1. The dimensionless kinematic variable αT is used to discriminate between events with genuine p→T miss associated with unobserved particles and spurious values of p→T miss arising from jet energy mismeasurements. No excess of event yields above the expected standard model backgrounds …

Measurements Of Jet Charge With Dijet Events In Pp Collisions At √S=8 Tev, A. M. Sirunyan, Marc M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohkmann, Daniel Noonan, Tuhin S. Roy, F. Yumiceva, The Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Jet charge is an estimator of the electric charge of a quark, antiquark, or gluon initiating a jet. It is based on the momentum-weighted sum of the electric charges of the jet constituents. Measurements of three charge observables of the leading jet in transverse momentum pT are performed with dijet events. The analysis is carried out with ata collected by the CMS experiment at the CERN LHC in proton-proton collisions at s=8 TeV corresponding to an integrated luminosity of 19.7fb−1. The results are presented as a function of the pT of the leading jet and compared to predictions from leading- …

Azimuthal Decorrelation Of Jets Widely Separated In Rapidity In Pp Collisions At √S = 7 Tev, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

The decorrelation in the azimuthal angle between the most forward and the most backward jets (Mueller-Navelet jets) is measured in data collected in pp collisions with the CMS detector at the LHC at s=7 TeV. The measurement is presented in the form of distributions of azimuthal-angle differences, Δϕ, between the Mueller-Navelet jets, the average cosines of (π − Δϕ), 2(π − Δϕ), and 3(π − Δϕ), and ratios of these cosines. The jets are required to have transverse momenta, pT, in excess of 35 GeV and rapidities, |y|, of less than 4.7. The results are presented as a function of …

Azimuthal Decorrelation Of Jets Widely Separated In Rapidity In Pp Collisions At √S = 7 Tev, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

The decorrelation in the azimuthal angle between the most forward and the most backward jets (Mueller-Navelet jets) is measured in data collected in pp collisions with the CMS detector at the LHC at s=7 TeV. The measurement is presented in the form of distributions of azimuthal-angle differences, Δϕ, between the Mueller-Navelet jets, the average cosines of (π − Δϕ), 2(π − Δϕ), and 3(π − Δϕ), and ratios of these cosines. The jets are required to have transverse momenta, pT, in excess of 35 GeV and rapidities, |y|, of less than 4.7. The results are presented as a function of …

Reconciling Ag-Star Formation, The Soltan Argument, And Meier's Paradox, David Garofalo, Matthew I. Kim, Damian J. Christian, Emily Hollingworth

Faculty and Research Publications

We provide a theoretical context for understanding the recent work of Kalfountzou et al. showing that star formation is enhanced at lower optical luminosity in radio-loud quasars. Our proposal for coupling the assumption of collimated FRII quasar-jet-induced star formation with lower accretion optical luminosity also explains the observed jet power peak in active galaxies at higher redshift compared to the peak in accretion power, doing so in a way that predicts the existence of a family of radio-quiet active galactic nuclei associated with rapidly spinning supermassive black holes at low redshift, as mounting observations suggest. The relevance of this work …

The Young Radio Lobe Of 3c 84: Inferred Gas Properties In The Central 10 Pc, Yutaka Fujita, Nozomu Kawakatu, Isaac Shlosman, Hirotaka Ito

Physics and Astronomy Faculty Publications

We analyse the environment of the supermassive black hole (SMBH) in the centre of a massive elliptical galaxy NGC 1275 in the Perseus cluster, hosting the radio source 3C 84. We focus on the young radio lobe observed inside the estimated Bondi accretion radius, and discusss the momentum balance between the jet associated with the lobe and the surrounding gas. The results are compared with the proper motion of the radio lobe obtained with the very long baseline interferometry. We find that under assumption of a high-density environment ( ≳ 100 cm⁻³), the jet power must be comparable …

The Broad-Lined Type Ic Sn 2012ap And The Nature Of Relativistic Supernovae Lacking A Gamma-Ray Burst Detection, D. Milisavljevic, R. Margutti, J. T. Parrent, A. M. Soderberg, R. A. Fesen

Dartmouth Scholarship

We present ultraviolet, optical, and near-infrared observations of SN 2012ap, a broad-lined Type Ic supernova in the galaxy NGC 1729 that produced a relativistic and rapidly decelerating outflow without a gamma-ray burst signature. Photometry and spectroscopy follow the flux evolution from –13 to +272 days past the B-band maximum of –17.4 ± 0.5 mag. The spectra are dominated by Fe II, O I, and Ca II absorption lines at ejecta velocities of v ≈ 20,000 km s^–1 that change slowly over time. Other spectral absorption lines are consistent with contributions from photospheric He I, and hydrogen may also …

Constraints Of The Radio-Loud/Radio-Quiet Dichotomy From The Fundamental Plane, David Garofalo, Matthew I. Kim, Damian J. Christian

Faculty and Research Publications

The Fundamental Plane for black hole activity constitutes a tight correlation between jet power, X-ray luminosity, and black hole mass. Under the assumption that a Blandford–Znajek-type mechanism, which relies on black hole spin, contributes non-negligibly to jet production, the sufficiently small scatter in the Fundamental Plane shows that black hole spin differences of |Δa| ∼ 1 are not typical among the active galactic nuclei population. If – as it seems – radio-loud and radio-quiet objects are both faithful to the Fundamental Plane, models of black hole accretion in which the radio-loud/radio-quiet dichotomy is based on a spin dichotomy of a∼1/a∼0, …

Test Of Models Of The Cosmic Infrared Background With Multiwavelength Observations Of The Blazar 1es 1218+30.4 In 2009, P. T. Reynolds

Physical Sciences Publications

We present the results of a multi-wavelength campaign targeting the blazar 1ES 1218+30.4 with observations with the 1.3 m McGraw-Hill optical telescope, the Rossi X-ray Timing Explorer (RXTE), the Fermi Gamma-Ray Space Telescope, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The RXTE and VERITAS observations were spread over a 13 day period and revealed clear evidence for flux variability, and a strong X-ray and γ-ray flare on 2009 February 26 (MJD 54888). The campaign delivered a well-sampled broadband energy spectrum with simultaneous RXTE and VERITAS very high energy (VHE, >100 GeV) observations, as well as …

The Jet-Disk Connection: Evidence For A Reinterpretation In Radio-Loud And Radio-Quiet Active Galactic Nuclei, David Garofalo

Faculty and Research Publications

To constrain models of the jet-disc connection, we explore Eddington ratios reported in Foschini (2011) and interpret them in relation to the values in Sikora et al. across the active galactic nuclei population from radio loud quasars, their flat spectrum radio quasar subclass, the recently discovered gamma-ray loud narrow-line type 1 Seyfert galaxies, Fanaroff-Riley type I (FRI) radio galaxies and radio quiet quasars of the Palomar Green survey. While appeal to disc truncation in radiatively inefficient flow appears to explain the observed inverse relation between radio loudness and Eddington ratio in radio loud and radio quiet quasars, FR I objects, …

Regulation Of Black Hole Winds And Jets Across The Mass Scale, A. L. King, J. M. Miller, J. Raymond, A. C. Fabian, C. S. Reynolds, K. Gültekin, E. M. Cackett, S. W. Allen, D. Proga, T. R. Kallman

Physics and Astronomy Faculty Research Publications

We present a study of the mechanical power generated by both winds and jets across the black hole mass scale. We begin with the study of ionized X-ray winds and present a uniform analysis using Chandra grating spectra. The high-quality grating spectra facilitate the characterization of the outflow velocity, ionization, and column density of the absorbing gas. We find that the kinetic power of the winds, derived from these observed quantities, scales with increasing bolometric luminosity as log (L _{wind, 42}/C_v ) = (1.58 ± 0.07)log (L _{Bol, 42}) - (3.19 ± 0.19). This suggests that supermassive …

Accretion Properties Of High- And Low-Excitation Young Radio Galaxies, Donghoon Son, Jong-Hak Woo, Sang Chul Kim, Hai Fu, Nozomu Kawakatu, Vardha N. Bennert, Tohru Nagao, Daeseong Park

Physics

Young radio galaxies (YRGs) provide an ideal laboratory to explore the connection between the accretion disk and radio jet thanks to their recent jet formation. We investigate the relationship between the emission-line properties, the black hole accretion rate, and the radio properties using a sample of 34 low-redshift (z < 0.4) YRGs. We classify YRGs as high-excitation galaxies (HEGs) and low-excitation galaxies (LEGs) based on the flux ratio of high-ionization to low-ionization emission lines. Using the Hα luminosities as a proxy of accretion rate, we find that HEGs in YRGs have ~1 dex higher Eddington ratios than LEGs in YRGs, suggesting that HEGs have a higher mass accretion rate or higher radiative efficiency than LEGs. In agreement with previous studies, we find that the luminosities of emission lines, in particular Hα, are correlated with radio core luminosity, suggesting that accretion and young radio activities are fundamentally connected.

A Distinctive Disk-Jet Coupling In The Seyfert-1 Active Galactic Nucleus Ngc 4051, A. L. King, J. M. Miller, E. M. Cackett, A. C. Fabian, S. Markoff, M. A. Nowak, M. Rupen, K. Gültekin, M. T. Reynolds

Physics and Astronomy Faculty Research Publications

We report on the results of a simultaneous monitoring campaign employing eight Chandra X-ray (0.5-10 keV) and six Very Large Array/Extended Very Large Array (8.4 GHz) radio observations of NGC 4051 over seven months. Evidence for compact jets is observed in the 8.4 GHz radio band; this builds on mounting evidence that jet production may be prevalent even in radio-quiet Seyferts. Assuming comparatively negligible local diffuse emission in the nucleus, the results also demonstrate an inverse correlation of L _radio ∝ L ^-0.72±0.04 _X-ray . If the A configuration is excluded in the case where diffuse emission plays a significant …

Scattering Amplitudes From Unitarity-Based Reduction Algorithm At The Integrand-Level, P. Mastrolia, Giovanni Ossola, T. Reiter, F. Tramontano

Publications and Research

Samurai is a tool for the automated numerical evaluation of one-loop corrections to any scattering amplitudes within the dimensional-regularization scheme. It is based on the decomposition of the integrand according to the OPP-approach, extended to accommodate an implementation of the generalized d-dimensional unitarity-cuts technique, and uses a polynomial interpolation exploiting the Discrete Fourier Transform. samurai can process integrands written either as numerator of Feynman diagrams or as product of tree-level amplitudes. We discuss some applications, among which the 6- and 8-photon scattering in QED, and the 6-quark scattering in QCD. samurai has been implemented as a Fortran90 library, publicly available, …

The June 2008 Flare Of Markarian 421 From Optical To Tev Energies, P. T. Reynolds, Et Al

Physical Sciences Publications

We present optical, X-ray, high-energy (30 GeV) and very high energy (100 GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 and June 23. A high-energy γ-ray signal was detected by AGILE with between June 9 and 15, with F(E>100 MeV) = 42+14 –12 × 10–8 photons cm–2 s–1. This flaring state is brighter than the average flux observed by EGRET by a factor of ~3, but still consistent with the highest EGRET flux. In hard X-rays (20-60 keV) SuperAGILE resolved a five-day flare (June 9-15) peaking at ~55 mCrab. SuperAGILE, …

A New Activity Phase Of The Blazar 3c 454.3 Multifrequency Observations By The Webt And Xmm-Newton In 2007-2008, Niall Smith, Et. Al.

Blackrock Castle Observatory Publications

Aims: The Whole Earth Blazar Telescope (WEBT) consortium has been monitoring the blazar 3C 454.3 from the radio to the optical bands since 2004 to study its emission variability properties.

Methods: We present and analyse the multifrequency results of the 2007-2008 observing season, including XMM-Newton observations and near-IR spectroscopic monitoring, and compare the recent emission behaviour with the past one. The historical mm light curve is presented here for the first time.

Results: In the optical band we observed a multi-peak outburst in July-August 2007, and other faster events in November 2007-February 2008. During these outburst phases, several episodes of …