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2018

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Articles 1 - 30 of 75

Full-Text Articles in Astrophysics and Astronomy

Application Of Bradford’S Law Of Scattering On Research Publication In Astronomy & Astrophysics Of India, Satish Kumar, Senthilkumar R. Dec 2018

Application Of Bradford’S Law Of Scattering On Research Publication In Astronomy & Astrophysics Of India, Satish Kumar, Senthilkumar R.

Library Philosophy and Practice (e-journal)

The present study is focused on examining the application of Bradford’s law of scattering on research articles published in the field of Astronomy & Astrophysics by Indian scientist during 1988-2017. The bibliographic data was retrieved from Web of Science (WoS) bibliographic data base for different period of time. Total 18,877 journal’s article have been published by Indian scientist in the field of Astronomy & Astrophysics during 1988-2017 which was further retrieved and analyzed separately for different blocks of 10 years as well as for 30 years consolidated too. The core journal of the field was identified. The Bradford law of …

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Challenges With Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato, B. Wang Dec 2018

Challenges With Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato, B. Wang

Physics Faculty Publications

We survey the current phenomenological status of semi-inclusive deeply inelastic scattering at moderate hard scales and in the limit of very large transverse momentum. As the transverse momentum becomes comparable to or larger than the overall hard scale, the differential cross sections should be calculable with fixed order perturbative QCD (pQCD) methods, while small transverse momentum (transverse-momentum-dependent factorization) approximations should eventually break down. We find large disagreement between HERMES and COMPASS data and fixed order calculations done with modern parton densities, even in regions of kinematics where such calculations should be expected to be very accurate. Possible interpretations are suggested.

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Graphene Used As A Lateral Force Microscopy Calibration Material In The Low-Load Non-Linear Regime, Mathias J. Boland, Jacob L. Hempel, Armin Ansary, Mohsen Nasseri, Douglas R. Strachan Nov 2018

Graphene Used As A Lateral Force Microscopy Calibration Material In The Low-Load Non-Linear Regime, Mathias J. Boland, Jacob L. Hempel, Armin Ansary, Mohsen Nasseri, Douglas R. Strachan

Physics and Astronomy Faculty Publications

A lateral force microscopy (LFM) calibration technique utilizing a random low-profile surface is proposed that is successfully employed in the low-load non-linear frictional regime using a single layer of graphene on a supporting oxide substrate. This calibration at low loads and on low friction surfaces like graphene has the benefit of helping to limit the wear of the LFM tip during the calibration procedure. Moreover, the low-profiles of the calibration surface characteristic of these layered 2D materials, on standard polished oxide substrates, result in a nearly constant frictional, adhesive, and elastic response as the tip slides over the surface, making …

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J/Ψ Production Cross Section And Its Dependence On Charged-Particle Multiplicity In P + P Collisions At √S=200 Gev, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, Renee H. Fatemi, Suvarna Ramachandran Nov 2018

J/Ψ Production Cross Section And Its Dependence On Charged-Particle Multiplicity In P + P Collisions At √S=200 Gev, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We present a measurement of inclusive J/ψ production at mid-rapidity (|y| < 1) in p+p collisions at a center-of-mass energy of √s=200 GeV with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The differential production cross section for J/ψ as a function of transverse momentum (pT) for 0 < pT < 14 GeV/c and the total cross section are reported and compared to calculations from the color evaporation model and the non-relativistic Quantum Chromodynamics model. The dependence of J/ψ relative yields in three pT intervals on charged-particle multiplicity at mid-rapidity is measured for …

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Search For A Dark Photon In Electroproduced E + E − Pairs With The Heavy Photon Search Experiment At Jlab, P. H. Adrian, N. A. Baltzell, M. Battaglieri, M. Bondí, S. Boyarinov, S. Bueltmann, G. Kalicy, H. Szumila-Vance, L. B. Weinstein, Heavy Photon Search Collaboration Nov 2018

Search For A Dark Photon In Electroproduced E + E − Pairs With The Heavy Photon Search Experiment At Jlab, P. H. Adrian, N. A. Baltzell, M. Battaglieri, M. Bondí, S. Boyarinov, S. Bueltmann, G. Kalicy, H. Szumila-Vance, L. B. Weinstein, Heavy Photon Search Collaboration

Physics Faculty Publications

The Heavy Photon Search experiment took its first data in a 2015 engineering run using a 1.056 GeV, 50 nA electron beam provided by CEBAF at the Thomas Jefferson National Accelerator Facility, searching for a prompt, electroproduced dark photon with a mass between 19 and 81  MeV/c2. A search for a resonance in the e+e− invariant mass distribution, using 1.7 days (1170  nb−1) of data, showed no evidence of dark photon decays above the large QED background, confirming earlier searches and demonstrating the full functionality of the experiment. Upper limits on the square …

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The Discovery Of A Gravitationally Lensed Supernova Ia At Redshift 2.22, David Rubin, Brian Hayden, Xiaosheng Huang, Greg Aldering, R Amanullah, K Barbary, K Boone, M Brodwin, S E. Deustua, S Dixon, P Eisenhardt, A S. Fruchter, A H. Gonzalez, A Goobar, R R. Gupta, I Hook, M. James Jee, A G. Kim, M Kowalski, C Lidman, E V. Linder, K Luther, J Nordin, R Pain, Saul Perlmutter, Z Raha, M Rigault, P Ruiz-Lapuente, C Saunders, C Sofiatti, A L. Spadafora, S A. Stanford, D Stern, N Suzuki, S C. Williams Oct 2018

The Discovery Of A Gravitationally Lensed Supernova Ia At Redshift 2.22, David Rubin, Brian Hayden, Xiaosheng Huang, Greg Aldering, R Amanullah, K Barbary, K Boone, M Brodwin, S E. Deustua, S Dixon, P Eisenhardt, A S. Fruchter, A H. Gonzalez, A Goobar, R R. Gupta, I Hook, M. James Jee, A G. Kim, M Kowalski, C Lidman, E V. Linder, K Luther, J Nordin, R Pain, Saul Perlmutter, Z Raha, M Rigault, P Ruiz-Lapuente, C Saunders, C Sofiatti, A L. Spadafora, S A. Stanford, D Stern, N Suzuki, S C. Williams

Physics and Astronomy

We present the discovery and measurements of a gravitationally lensed supernova (SN) behind the galaxy cluster MOO J1014+0038. Based on multi-band Hubble Space Telescope and Very Large Telescope (VLT) photometry of the supernova, and VLT spectroscopy of the host galaxy, we find a 97.5% probability that this SN is a SN Ia, and a 2.5% chance of a CC SN. Our typing algorithm combines the shape and color of the light curve with the expected rates of each SN type in the host galaxy. With a redshift of 2.2216, this is the highest redshift SN Ia discovered with a spectroscopic …

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Collision Energy Dependence Of Moments Of Net-Kaon Multiplicity Distributions At Rhic, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, Renee H. Fatemi, Suvarna Ramachandran Oct 2018

Collision Energy Dependence Of Moments Of Net-Kaon Multiplicity Distributions At Rhic, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

Fluctuations of conserved quantities such as baryon number, charge, and strangeness are sensitive to the correlation length of the hot and dense matter created in relativistic heavy-ion collisions and can be used to search for the QCD critical point. We report the first measurements of the moments of net-kaon multiplicity distributions in Au+Au collisions at √sNN=7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV. The collision centrality and energy dependence of the mean (M), variance (σ2), skewness (S), and kurtosis (κ) for net-kaon multiplicity distributions as well …

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No Net Charge Separation In Hot Qcd In A Magnetic Field, Efrain J. Ferrer, Vivian De La Incera Oct 2018

No Net Charge Separation In Hot Qcd In A Magnetic Field, Efrain J. Ferrer, Vivian De La Incera

Physics and Astronomy Faculty Publications and Presentations

We study the realization of axion electrodynamics in QCD in the presence of a background magnetic field at temperatures high enough for the occurrence of topological charge transitions that are reflected in the presence of a 𝜃-vacuum term in the action. We show that in this system, the Maxwell equations contain two equal and opposite electric currents that are proportional to the time derivative of the axion field 𝜃. One of these currents comes directly from the Abelian chiral anomaly term in the action and can be interpreted as a polarization current due to the magnetoelectricity of the system with …

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Event Engineering Studies For Heavy Flavor Production And Hadronization In High Multiplicity Hadron-Hadron And Hadron-Nucleus Collisions, Yan-Qing Ma, Prithwish Tribedy, Raju Venugopalan, Kazuhiro Watanabe Oct 2018

Event Engineering Studies For Heavy Flavor Production And Hadronization In High Multiplicity Hadron-Hadron And Hadron-Nucleus Collisions, Yan-Qing Ma, Prithwish Tribedy, Raju Venugopalan, Kazuhiro Watanabe

Physics Faculty Publications

Heavy flavor measurements in high multiplicity proton-proton and proton-nucleus collisions at collider energies enable unique insights into their production and hadronization mechanism because experimental and theoretical uncertainties cancel in ratios of their cross sections relative to minimum bias events. We explore such event engineering using the color glass condensate (CGC) effective field theory to compute short-distance charmonium cross sections. The CGC is combined with heavy-quark fragmentation functions to compute D-meson cross sections; for the J/ψ, hadronization is described employing nonrelativistic QCD (NRQCD) and an improved color evaporation model. Excellent agreement is found between the CGC computations and the LHC heavy …

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An Acoustical Analogue Of A Galactic-Scale Gravitational-Wave Detector, Michael T. Lam, Joseph D. Romano, Joey Key, M. E. Normandin, ‪Jeffrey S. Hazboun Oct 2018

An Acoustical Analogue Of A Galactic-Scale Gravitational-Wave Detector, Michael T. Lam, Joseph D. Romano, Joey Key, M. E. Normandin, ‪Jeffrey S. Hazboun

Physics and Astronomy Faculty Publications and Presentations

By precisely monitoring the “ticks” of Nature's most precise clocks (millisecond pulsars), scientists are trying to detect the “ripples in spacetime” (gravitational waves) produced by the inspirals of supermassive black holes in the centers of distant merging galaxies. Here, we describe a relatively simple demonstration that uses two metronomes and a microphone to illustrate several techniques used by pulsar astronomers to search for and detect gravitational waves. An adapted version of this demonstration could be used as an instructional laboratory investigation at the undergraduate level.

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Yukawa Potential Orbital Energy: Its Relation To Orbital Mean Motion As Well To The Graviton Mediating The Interaction In Celestial Bodies, Connor Martz, Sheldon Van Middelkoop, Ioannis Gkigkitzis, Ioannis Haranas, Ilias S. Kotsireas Sep 2018

Yukawa Potential Orbital Energy: Its Relation To Orbital Mean Motion As Well To The Graviton Mediating The Interaction In Celestial Bodies, Connor Martz, Sheldon Van Middelkoop, Ioannis Gkigkitzis, Ioannis Haranas, Ilias S. Kotsireas

Physics and Computer Science Faculty Publications

Research on gravitational theories involves several contemporary modified models that predict the existence of a non-Newtonian Yukawa-type correction to the classical gravitational potential. In this paper we consider a Yukawa potential and we calculate the time rate of change of the orbital energy as a function of the orbital mean motion for circular and elliptical orbits. In both cases we find that there is a logarithmic dependence of the orbital energy on the mean motion. Using that, we derive an expression for the mean motion as a function of the Yukawa orbital energy, as well as specific Yukawa potential parameters. …

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On The Dynamics Of Near-Extremal Black Holes, Pranjal Nayak, Ashish Shukla, Ronak M. Soni, Sandip P. Trivedi, V. Vishal Sep 2018

On The Dynamics Of Near-Extremal Black Holes, Pranjal Nayak, Ashish Shukla, Ronak M. Soni, Sandip P. Trivedi, V. Vishal

Physics and Astronomy Faculty Publications

We analyse the dynamics of near-extremal Reissner-Nordström black holes in asymptotically four-dimensional Anti de Sitter space (AdS4). We work in the spherically symmetric approximation and study the thermodynamics and the response to a probe scalar field. We find that the behaviour of the system, at low energies and to leading order in our approximations, is well described by the Jackiw-Teitelboim (JT) model of gravity. In fact, this behaviour can be understood from symmetry considerations and arises due to the breaking of time reparametrisation invariance. The JT model has been analysed in considerable detail recently and related to the …

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Beam Energy Dependence Of Rapidity-Even Dipolar Flow In Au + Au Collisions, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, Renee H. Fatemi, Suvarna Ramachandran Sep 2018

Beam Energy Dependence Of Rapidity-Even Dipolar Flow In Au + Au Collisions, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

New measurements of directed flow for charged hadrons, characterized by the Fourier coefficient v1, are presented for transverse momenta pT, and centrality intervals in Au+Au collisions recorded by the STAR experiment for the center-of-mass energy range √sNN=7.7–200 GeV. The measurements underscore the importance of momentum conservation, and the characteristic dependencies on √sNN, centrality and pT are consistent with the expectations of geometric fluctuations generated in the initial stages of the collision, acting in concert with a hydrodynamic-like expansion. The centrality and pT dependencies of v1even …

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Photoproduction Of K+ K- Meson Pairs On The Proton, S. Lombardo, M. Battaglieri, A. Celentano, A. D'Angelo, R. De Vita, A. Filippi, D. I. Glazier, M. Khachatryan, A. Klein, Y. Prok, The Clas Collaboration Sep 2018

Photoproduction Of K+ K- Meson Pairs On The Proton, S. Lombardo, M. Battaglieri, A. Celentano, A. D'Angelo, R. De Vita, A. Filippi, D. I. Glazier, M. Khachatryan, A. Klein, Y. Prok, The Clas Collaboration

Physics Faculty Publications

The exclusive reaction γp → pK+K− was studied in the photon energy range 3.0–3.8 GeV and momentum transfer range 0.6 < −t< 1.3 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. In this kinematic range the integrated luminosity was approximately 20 pb−1. The reaction was isolated by detecting the K+ and the proton in CLAS, and reconstructing the K− via the missing-mass technique. Moments of the dikaon decay angular distributions were extracted from the experimental data. Besides the dominant contribution of the ϕ meson in the P wave, …

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Underwater Adhesive Using Solid–Liquid Polymer Mixes, Alin Cristian Chipara, T. Tsafack, P. S. Owuor, J. Yeon, C. E. Junkermeier, A. C. T. Van Duin, S. Bhowmick, S. A. S. Asif, S. Radhakrishnan, Mircea Chipara Sep 2018

Underwater Adhesive Using Solid–Liquid Polymer Mixes, Alin Cristian Chipara, T. Tsafack, P. S. Owuor, J. Yeon, C. E. Junkermeier, A. C. T. Van Duin, S. Bhowmick, S. A. S. Asif, S. Radhakrishnan, Mircea Chipara

Physics and Astronomy Faculty Publications and Presentations

Instantaneous adhesion between different materials is a requirement for several applications ranging from electronics to biomedicine. Approaches such as surface patterning, chemical cross-linking, surface modification, and chemical synthesis have been adopted to generate temporary adhesion between various materials and surfaces. Because of the lack of curing times, temporary adhesives are instantaneous, a useful property for specific applications that need quick bonding. However, to this day, temporary adhesives have been mainly demonstrated under dry conditions and do not work well in submerged or humid environments. Furthermore, most rely on chemical bonds resulting from strong interactions with the substrate such as acrylate …

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Dark Energy Survey Year 1 Results: Cosmological Constraints From Galaxy Clustering And Weak Lensing, T. M. C. Abbott, F. B. Abdalla, A. Alarcon, J. Aleksic, S. Allam, S. Allen, A. Amara, J. Annis, J. Asorey, S. Avila, D. Bacon, E. Balbinot, M. Banerji, N. Banik, Wayne Barkhouse Aug 2018

Dark Energy Survey Year 1 Results: Cosmological Constraints From Galaxy Clustering And Weak Lensing, T. M. C. Abbott, F. B. Abdalla, A. Alarcon, J. Aleksic, S. Allam, S. Allen, A. Amara, J. Annis, J. Asorey, S. Avila, D. Bacon, E. Balbinot, M. Banerji, N. Banik, Wayne Barkhouse

Physics Faculty Publications

We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321  deg2 of griz imaging data from the first year of the Dark Energy Survey (DES Y1). We combine three two-point functions: (i) the cosmic shear correlation function of 26 million source galaxies in four redshift bins, (ii) the galaxy angular autocorrelation function of 650,000 luminous red galaxies in five redshift bins, and (iii) the galaxy-shear cross-correlation of luminous red galaxy positions and source galaxy shears. To demonstrate the robustness of these results, we use independent pairs of galaxy shape, photometric-redshift estimation and validation, …

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Nitrogen-To-Oxygen Abundance Ratio Variation In Quiescent Galaxies, Renbin Yan Aug 2018

Nitrogen-To-Oxygen Abundance Ratio Variation In Quiescent Galaxies, Renbin Yan

Physics and Astronomy Faculty Publications

For the first time, we establish a gas-phase abundance pattern calibration for quiescent galaxies using optical emission lines. Quiescent galaxies have warm ionized gas showing line ratios similar to low-ionization nuclear emission line regions. The ionization mechanism for the gas is still an unsettled puzzle. Despite the uncertainty in the ionization mechanism, we argue that we can still infer certain gas-phase abundance pattern from first principles. We show that the relative trend in N/O abundance can still be reliably measured based on [N II] λλ6548,6583/[O II] λλ3726,3729 and a direct measurement of the electron temperature. We construct a composite direct …

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Suppression Of Dielectronic Recombination Due To Finite Density Effects. Ii. Analytical Refinement And Application To Density-Dependent Ionization Balances And Agn Broad-Line Emission, D. Nikolić, T. W. Gorczyca, K. T. Korista, Marios Chatzikos, Gary J. Ferland, Francisco Guzmán, P. A. M. Van Hoof, R. J. R. Williams, N. R. Badnell Aug 2018

Suppression Of Dielectronic Recombination Due To Finite Density Effects. Ii. Analytical Refinement And Application To Density-Dependent Ionization Balances And Agn Broad-Line Emission, D. Nikolić, T. W. Gorczyca, K. T. Korista, Marios Chatzikos, Gary J. Ferland, Francisco Guzmán, P. A. M. Van Hoof, R. J. R. Williams, N. R. Badnell

Physics and Astronomy Faculty Publications

We present improved fits to our treatment of suppression of dielectronic recombination at intermediate densities. At low densities, most recombined excited states eventually decay to the ground state, and therefore the total dielectronic recombination rate to all levels is preserved. At intermediate densities, on the other hand, collisions can lead to ionization of higher-lying excited states, thereby suppressing the dielectronic recombination rate. The improved suppression factors presented here, although highly approximate, allow summed recombination rate coefficients to be used to intermediate densities. There have been several technical improvements to our previously presented fits. For H- through B-like ions the activation …

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A Search For Possible Long Range Spin Dependent Interactions Of The Neutron From Exotic Vector Boson Exchange, C. Haddock, J. Amadio, E. Anderson, L. Barrón-Palos, B. Crawford, Christopher B. Crawford, D. Esposito, W. Fox, I. Francis, J. Fry, H. Gardiner, A. Holley, K. Korsak, J. Lieffers, S. Magers, M. Maldonado-Velázquez, D. Mayorov, J. S. Nico, T. Okudaira, C. Paudel, S. Santra, M. Sarsour, H. M. Shimizu, W. M. Snow, Aaron P. Sprow, K. Steffen, H. E. Swanson, F. Tovesson, J. Vanderwerp, P. A. Yergeau Aug 2018

A Search For Possible Long Range Spin Dependent Interactions Of The Neutron From Exotic Vector Boson Exchange, C. Haddock, J. Amadio, E. Anderson, L. Barrón-Palos, B. Crawford, Christopher B. Crawford, D. Esposito, W. Fox, I. Francis, J. Fry, H. Gardiner, A. Holley, K. Korsak, J. Lieffers, S. Magers, M. Maldonado-Velázquez, D. Mayorov, J. S. Nico, T. Okudaira, C. Paudel, S. Santra, M. Sarsour, H. M. Shimizu, W. M. Snow, Aaron P. Sprow, K. Steffen, H. E. Swanson, F. Tovesson, J. Vanderwerp, P. A. Yergeau

Physics and Astronomy Faculty Publications

We present a search for possible spin dependent interactions of the neutron with matter through exchange of spin 1 bosons with axial vector couplings as envisioned in possible extensions of the Standard Model. This was sought using a slow neutron polarimeter that passed transversely polarized slow neutrons by unpolarized slabs of material arranged so that interactions would tilt the plane of polarization and develop a component along the neutron momentum. The result for the rotation angle, ϕ′=[2.8±4.6(stat.)±4.0(sys.)]×10−5 rad/m is consistent with zero. This result improves the upper bounds on the neutron-matter coupling g2A …

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Correlation Measurements Between Flow Harmonics In Au + Au Collisions At Rhic, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, Renee H. Fatemi, Suvarna Ramachandran Aug 2018

Correlation Measurements Between Flow Harmonics In Au + Au Collisions At Rhic, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

Flow harmonics (vn) in the Fourier expansion of the azimuthal distribution of particles are widely used to quantify the anisotropy in particle emission in high-energy heavy-ion collisions. The symmetric cumulants, SC(m,n), are used to measure the correlations between different orders of flow harmonics. These correlations are used to constrain the initial conditions and the transport properties of the medium in theoretical models. In this Letter, we present the first measurements of the four-particle symmetric cumulants in Au+Au collisions at √sNN=39 and 200 GeV from data collected by the …

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Shocks Or Photoionization: Direct Temperature Measurements Of The Low-Ionization Gas In Quiescent Galaxies, Renbin Yan Aug 2018

Shocks Or Photoionization: Direct Temperature Measurements Of The Low-Ionization Gas In Quiescent Galaxies, Renbin Yan

Physics and Astronomy Faculty Publications

The ionization mechanism of the low-ionization gas in quiescent red-sequence galaxies has been a long-standing puzzle. Direct temperature measurements would put strong constraints on this issue. We carefully selected a sample of quiescent red-sequence galaxies from Sloan Digital Sky Survey. We bin them into three bins with different [N II]/H α and [N II]/[O II] ratios, and we measure the temperature-sensitive [O III] λ4363, [N II] λ5755, [S II] λλ4068, 4076, and [O II] λλ7320, 7330 lines in the stacked spectra. The [S II] doublet ratios indicate the line-emitting gas is in the low-density regime (∼10–200 cm−3). We …

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Fluctuating Hydrodynamics Of Reactive Liquid Mixtures, Changho Kim, Andy. Nonaka, John Bell, Alejandro Garcia, Aleksandar Donev Aug 2018

Fluctuating Hydrodynamics Of Reactive Liquid Mixtures, Changho Kim, Andy. Nonaka, John Bell, Alejandro Garcia, Aleksandar Donev

Faculty Publications

Fluctuating hydrodynamics (FHD) provides a framework for modeling microscopic fluctuations in a manner consistent with statistical mechanics and nonequilibrium thermodynamics. This paper presents an FHD formulation for isothermal reactive incompressible liquid mixtures with stochastic chemistry. Fluctuating multispecies mass diffusion is formulated using a Maxwell–Stefan description without assuming a dilute solution, and momentum dynamics is described by a stochastic Navier–Stokes equation for the fluid velocity. We consider a thermodynamically consistent generalization for the law of mass action for non-dilute mixtures and use it in the chemical master equation (CME) to model reactions as a Poisson process. The FHD approach provides remarkable …

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Cause Of Cambrian Explosion - Terrestrial Or Cosmic?, Edward J. Steele, Shirwan Al-Mufti, Kenneth A. Augustyn, Rohana Chandrajith, John P. Coghlan, S. G. Coulson, Et. Al. Aug 2018

Cause Of Cambrian Explosion - Terrestrial Or Cosmic?, Edward J. Steele, Shirwan Al-Mufti, Kenneth A. Augustyn, Rohana Chandrajith, John P. Coghlan, S. G. Coulson, Et. Al.

Michigan Tech Publications

We review the salient evidence consistent with or predicted by the Hoyle-Wickramasinghe (H-W) thesis of Cometary (Cosmic) Biology. Much of this physical and biological evidence is multifactorial. One particular focus are the recent studies which date the emergence of the complex retroviruses of vertebrate lines at or just before the Cambrian Explosion of ∼500 Ma. Such viruses are known to be plausibly associated with major evolutionary genomic processes. We believe this coincidence is not fortuitous but is consistent with a key prediction of H-W theory whereby major extinction-diversification evolutionary boundaries coincide with virus-bearing cometary-bolide bombardment events. A second focus is …

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First Measurement Of Ξ− Polarization In Photoproduction, J. Bono, L. Guo, K. P. Adhikari, M. J. Amaryan, G. Charles, G. Gavalian, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao Aug 2018

First Measurement Of Ξ− Polarization In Photoproduction, J. Bono, L. Guo, K. P. Adhikari, M. J. Amaryan, G. Charles, G. Gavalian, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao

Physics Faculty Publications

Despite decades of studies of the photoproduction of hyperons, both their production mechanisms and their spectra of excited states are still largely unknown. While the parity-violating weak decay of hyperons offers a means of measuring their polarization, which could help discern their production mechanisms and identify their excitation spectra, no such study has been possible for doubly strange baryons in photoproduction, due to low production cross sections. However, by making use of the reaction γ p → K+K+Ξ−, we have measured, for the first time, the induced polarization, P, and the transferred polarization from circularly polarized …

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Space-Time In The Syk Model, Sumit R. Das, Aminik Ghosh, Antal Jevicki, Kenta Suzuki Jul 2018

Space-Time In The Syk Model, Sumit R. Das, Aminik Ghosh, Antal Jevicki, Kenta Suzuki

Physics and Astronomy Faculty Publications

We consider the question of identifying the bulk space-time of the SYK model. Focusing on the signature of emergent space-time of the (Euclidean) model, we explain the need for non-local (Radon-type) transformations on external legs of n-point Green’s functions. This results in a dual theory with Euclidean AdS signature with additional legfactors. We speculate that these factors incorporate the coupling of additional bulk states similar to the discrete states of 2d string theory.

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Path Integral Complexity For Perturbed Cfts, Arpan Bhattacharyya, Pawal Caputa, Sumit R. Das, Nilay Kundu, Masamichi Miyaji, Tadashi Takayanagi Jul 2018

Path Integral Complexity For Perturbed Cfts, Arpan Bhattacharyya, Pawal Caputa, Sumit R. Das, Nilay Kundu, Masamichi Miyaji, Tadashi Takayanagi

Physics and Astronomy Faculty Publications

In this work, we formulate a path-integral optimization for two dimensional conformal field theories perturbed by relevant operators. We present several evidences how this optimization mechanism works, based on calculations in free field theories as well as general arguments of RG flows in field theories. Our optimization is performed by minimizing the path-integral complexity functional that depends on the metric and also on the relevant couplings. Then, we compute the optimal metric perturbatively and find that it agrees with the time slice of the hyperbolic metric perturbed by a scalar field in the AdS/CFT correspondence. Last but not the least, …

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Molpop-Cep: An Exact, Fast Code For Multi-Level Systems, Andrés Asensio Ramos, Moshe Elitzur Jul 2018

Molpop-Cep: An Exact, Fast Code For Multi-Level Systems, Andrés Asensio Ramos, Moshe Elitzur

Physics and Astronomy Faculty Publications

We present MOLPOP-CEP, a universal line transfer code that allows the exact calculation of multi-level line emission from a slab with variable physical conditions for any arbitrary atom or molecule for which atomic data exist. The code includes error control to achieve any desired level of accuracy, providing full confidence in its results. Publicly available, MOLPOP-CEP employs our recently developed coupled escape probability (CEP) technique, whose performance exceeds other exact methods by orders of magnitude. The program also offers the option of an approximate solution with different variants of the familiar escape probability method. As an illustration of the MOLPOP-CEP …

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Characterization Of Eight Potentially Hazardous Near Earth Asteroids: Rotation Period Analysis And Structure Modeling Via Light Curve Inversion Techniques, Stacy Jo Hicks Jul 2018

Characterization Of Eight Potentially Hazardous Near Earth Asteroids: Rotation Period Analysis And Structure Modeling Via Light Curve Inversion Techniques, Stacy Jo Hicks

Masters Theses & Specialist Projects

The term “homeland security”, seems to have become synonymous with terrorism in the minds of the general public. However, there are other threats to the security of the United States homeland that can be just as, if not more, devastating than terrorism. Included among these other threats is the potential of an asteroid collision with Earth. Historically, asteroid impact events have been responsible for the devastation of our planet and many of the mass extinction events encountered throughout the geologic record. Knowledge of physical parameters such as structure and rotational dynamics of the asteroid are critical parameters in developing interception …

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Finite-Volume Effects Due To Spatially Nonlocal Operators, Raúl A. Briceño, Juan V. Guerrero, Maxwell T. Hansen, Christopher J. Monahan Jul 2018

Finite-Volume Effects Due To Spatially Nonlocal Operators, Raúl A. Briceño, Juan V. Guerrero, Maxwell T. Hansen, Christopher J. Monahan

Physics Faculty Publications

Spatially nonlocal matrix elements are useful lattice-QCD observables in a variety of contexts, for example in determining hadron structure. To quote credible estimates of the systematic uncertainties in these calculations, one must understand, among other things, the size of the finite-volume effects when such matrix elements are extracted from numerical lattice calculations. In this work, we estimate finite- volume effects for matrix elements of nonlocal operators, composed of two currents displaced in a spatial direction by a distance ξ. We find that the finite-volume corrections depend on the details of the matrix element. If the external state is the lightest …

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One-Loop Evolution Of Parton Pseudo-Distribution Functions On The Lattice, Anatoly Radyushkin Jul 2018

One-Loop Evolution Of Parton Pseudo-Distribution Functions On The Lattice, Anatoly Radyushkin

Physics Faculty Publications

We incorporate recent calculations of one-loop corrections for the reduced Ioffe-time pseudo-distribution m(v, z(3)(2) thorn to extend the leading-logarithm analysis of lattice data obtained by Orginos et al. We observe that the one-loop corrections contain a large term reflecting the fact that effective distances involved in the most important diagrams are much smaller than the nominal distance z(3). The large correction in this case may be absorbed into the evolution term, and the perturbative expansion used for extraction of parton densities at the μ ≈ 2 GeV scale is under control. The extracted parton distribution is rather close to global …

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