Physics Commons^™

High Pressure Line Shapes Of The Rb D1 And D2 Lines For 4He And 3He Collisions, Wooddy S. Miller, Christopher A. Rice, Gordon D. Hager, Matthew D. Rotondaro, Hamid Berriche, Glen P. Perram

Faculty Publications

Line shapes for the Rb D₁ (5²S_1/2 ↔ 5²P_1/2) and D₂ (5²S_1/2 ↔ 5²P_3/2) transitions with ⁴He and ³He collisions at pressures of 500–15,000 Torr and temperatures of 333–533 K have been experimentally observed and compared to predictions from the Anderson–Talman theory. The ground X²Σ⁺_1/2 and excited A²Π_1/2, A²Π_3/2, and B²Σ⁺_1/2 potential energy surfaces required for the line shape predictions have been calculated using a one-electron …

Target And Beam-Target Spin Asymmetries In Exclusive Π+ And Π− Electroproduction With 1.6- To 5.7-Gev Electrons, P. E. Bosted, A. S. Biselli, S. Careccia, G. Dodge, R. Fersch, N. Guler, S. E. Kuhn, J. Pierce, Y. Prok, X. Zheng, K. P. Adhikari, D. Adikaram, Z. Akbar, M. J. Amaryan, S. Anefalos Pereira, G. Asryan, H. Avakian, R. A. Badui, J. Ball, N. A. Baltzell, M. Battaglieri, V. Batourine, I. Bedlinskiy, S. Boiarinov, W. J. Briscoe, S. Bültmann, V. D. Burkert, T. Cao, D. S. Carman, A. Celentano, Wesley P. Gohn

Physics and Astronomy Faculty Publications

Beam-target double-spin asymmetries and target single-spin asymmetries in exclusive π+ and quasiexclusive π− electroproduction were obtained from scattering of 1.6- to 5.7-GeV longitudinally polarized electrons from longitudinally polarized protons (for π+) and deuterons (for π−) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic range covered is 1.1 < W < 2.6 GeV and 0.05 < Q² < 5 GeV², with good angular coverage in the forward hemisphere. The asymmetry results were divided into approximately 40 000 kinematic bins for π+ from free protons and 15 000 bins for π− production from bound nucleons in the deuteron. The …

Measurement Of Elliptic Flow Of Light Nuclei At √SNn = 200, 62.4, 39, 27, 19.6, 11.5, And 7.7 Gev At The Bnl Relativistic Heavy Ion Collider, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, D. Cebra, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We present measurements of second-order azimuthal anisotropy (υ₂) at midrapidity (|y| < 1.0) for light nuclei d, t, ³He (for ⎷^s_NN = 200 GeV) in the STAR (Solenoidal Tracker at RHIC) experiment. The υ₂ for these light nuclei produced in heavy-ion collisions is compared with those for p and p¯. We observe mass ordering in nuclei υ₂ (p_T) at low transverse momenta (p_T < 2.0 GeV/c). We also find a centrality dependence of υ₂ for d and d¯. The magnitude of υ₂ for t and ³He …

Nucleon Decay, Atmospheric Neutrinos, And Cosmic Rays At Dune: September 2016 Progress Report, E. Church, D. Dwyer, H. Gallagher, M. Goodman, R. Hatcher, J. Hewes, A. Higuera, V. A. Kudryavtsev, L. Lin, N. Martinez, H. Méndez, J. L. Raaf, M. Robinson, G. Santucci, M. Sorel, A. Tonazzo, T. K. Warburton, K. Wood, T. Yang

Progress Reports

We report on the progress made within the Nucleon Decay, Atmospheric Neutrinos, and Cosmogenics Physics Working Groups since the DUNE CDR, and in particular in the period September 2015 { September 2016. This note is also intended to provide input for the September 2016 Preliminary Report of the Far Detector Task Force. We report jointly for the three WGs since they are tightly coupled. They make use of the same DUNE Far Detector for their physics studies, they share the same energy regime, and they are all characterized by random, non-beam triggers. Finally, cosmogenic events are a background for atmospheric …

Beam-Energy Dependence Of Charge Balance Functions From Au+Au Collisions At Energies Available At The Bnl Relativistic Heavy Ion Collider, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, A. Banerjee, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, A. V. Brandin, I. Bunzarov, T. P. Burton, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, D. Cebra, M. C. Cervantes, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

Balance functions have been measured in terms of relative pseudorapidity (Δη) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at √^s_NN = 7.7GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at √^s_NN = 2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions …

The Rise Of Nuclear Energy In Arab States: Future Impacts, Brittany Broder

Mahurin Honors College Capstone Experience/Thesis Projects

The signing of the Iranian nuclear deal during the Summer of 2015 highlighted the threat of nuclear proliferation from foreign powers, but largely overlooked the rise of nuclear energy in the Middle East and North Africa (MENA). With growing energy demands and heightened environmental regulations, countries in this region are turning to nuclear power to fuel their next generation. However, the rise of nuclear power in the MENA region holds serious implications for the future of the area’s energy, economic, and social reforms that have largely gone unexplored as a whole thus far. The purpose of this thesis is to …

Protophobic Fifth-Force Interpretation Of The Observed Anomaly In 8Be Nuclear Transitions, Jonathan L. Feng, Bartosz Fornal, Iftah Galon, Susan Gardner, Jordan Smolinsky, Tim M. P. Tait, Philip Tanedo

Physics and Astronomy Faculty Publications

Recently a 6.8σ anomaly has been reported in the opening angle and invariant mass distributions of e⁺e⁻ pairs produced in ⁸Be nuclear transitions. The data are explained by a 17 MeV vector gauge boson X that is produced in the decay of an excited state to the ground state, ⁸Be^∗ → ⁸Be X, and then decays through X → e⁺e⁻. The X boson mediates a fifth force with a characteristic range of 12 fm and has millicharged couplings to up and down quarks and electrons, and a …

0+ States In 130,132Xe: A Search For E(5) Behavior, Erin E. Peters, T. J. Ross, S. F. Ashley, Anagha Chakraborty, Benjamin P. Crider, M. D. Hennek, Sinong Liu, Marcus T. Mcellistrem, Sharmistha Mukhopadhyay, Francisco M. Prados-Estévez, Anthony Paul Ramirez, J. S. Thrasher, Steven W. Yates

Chemistry Faculty Publications

The level structures of ^130,132Xe were studied with the inelastic neutron scattering reaction followed by γ-ray detection. Level lifetimes were measured using the Doppler-shift attenuation method and low-lying excited states in these nuclei were characterized. With a focus on the decay properties of the 0⁺ states, these nuclei were examined as representations of the E(5) critical-point symmetry.

Near-Side Azimuthal And Pseudorapidity Correlations Using Neutral Strange Baryons And Mesons In D+Au, Cu+Cu, And Au+Au Collisions At √SNn = 200 Gev, B. Abelev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, L. S. Barnby, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, M. Bombara, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We present measurements of the near side of triggered di-hadron correlations using neutral strange baryons (Λ, Λ⁻) and mesons (K⁰_S) at intermediate transverse momentum (3 < p_T < 6 GeV/c) to look for possible flavor and baryon-meson dependence. This study is performed in d+Au, Cu+Cu, and Au+Au collisions at √^S_NN = 200 GeV measured by the STAR experiment at RHIC. The near-side di-hadron correlation contains two structures, a peak which is narrow in azimuth and pseudorapidity consistent with correlations from jet fragmentation, and a correlation in azimuth which is broad in pseudorapidity. The …

The Beam-Helicity Asymmetry For Two Pseudoscalar Mesons In Photoproduction And A Partial Wave Analysis For Excited Hyperons, Rafael A. Badui

FIU Electronic Theses and Dissertations

The first-time measurement of the angular dependence of the beam-helicity asymmetry for $\gamma p \rightarrow pK^{+}K^{-}$ is shown and compared to $\gamma p \rightarrow p\pi^{+}\pi^{-}$. The data obtained were from the CLAS g12 experiment at Jefferson Lab. The experiment utilized a beam of circularly polarized photons with energies between 1.1 and 5.4 GeV incident on an unpolarized liquid hydrogen target, which produced an unprecedented number of strange hadrons in photoproduction. The production mechanism for strange hadrons is not well understood. The beam-helicity asymmetry is a polarization observable that provides information on interfering production mechanisms in the reaction. It is shown …

Precision Measurement Of The Radiative Β Decay Of The Free Neutron, M. J. Bales, R. Alarcon, C. D. Bass, E. J. Beise, H. Breuer, J. Byrne, T. E. Chupp, K. J. Coakley, R. L. Cooper, M. S. Dewey, Susan Gardner, T. R. Gentile, D. He, H. P. Mumm, J. S. Nico, B. O'Neill, A. K. Thompson, F. E. Wietfeldt

Physics and Astronomy Faculty Publications

The standard model predicts that, in addition to a proton, an electron, and an antineutrino, a continuous spectrum of photons is emitted in the β decay of the free neutron. We report on the RDK II experiment which measured the photon spectrum using two different detector arrays. An annular array of bismuth germanium oxide scintillators detected photons from 14 to 782 keV. The spectral shape was consistent with theory, and we determined a branching ratio of 0.00335 ± 0.00005[stat] ± 0.00015[syst]. A second detector array of large area avalanche photodiodes directly detected photons from 0.4 to 14 keV. For this …

J/Ψ Production At Low Transverse Momentum In P + P And D + Au Collisions At √SNn = 200 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, D. Cebra, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We report on the measurement of J/ψ production in the dielectron channel at midrapidity (|y| < 1) in p + p and d + Au collisions at √^s_NN = 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider. The transverse momentum p_Tspectra in p + p for p_T < 4 GeV/c and d + Au collisions for p_T < 3 GeV/c are presented. These measurements extend the STAR coverage for J/ψ production in p + p collisions to low p_T. The ⟨p²_T⟩ from the measured J/ψ invariant …

Characterization Of The Non-Uniqueness Of Used Nuclear Fuel Burnup Signatures Through A Mesh-Adaptive Direct Search, Steven Skutnik, David R. Davis

Faculty Publications and Other Works -- Nuclear Engineering

The use of passive gamma and neutron signatures from fission indicators is a common means of estimating used fuel burnup, enrichment, and cooling time. However, while characteristic fission product signatures such as ¹³⁴Cs, ¹³⁷Cs and ¹⁵⁴Eu, and others are generally reliable estimators for used fuel burnup within the context where the assembly initial enrichment and the discharge time are known, in the absence of initial enrichment and/or cooling time information (such as when applying NDA measurements in a safeguards/verification context), these fission product indicators no longer yield a unique solution for assembly enrichment, burnup, and cooling time …

Measurement Of The Transverse Single-Spin Asymmetry In P↑+P→W±/Z0 At Rhic, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, A. Banerjee, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at √s = 500  GeV by the STAR experiment at RHIC. The measured observable is sensitive to the Sivers function, one of the transverse-momentum-dependent parton distribution functions, which is predicted to have the opposite sign in proton-proton collisions from that observed in deep inelastic lepton-proton scattering. These data provide the first experimental investigation of the nonuniversality of the Sivers function, fundamental to our understanding of QCD.

An Old And New Start To Russian—United States Nuclear Arms Control Agreements, Samantha Pitz

Independent Study Project (ISP) Collection

The Russian Federation and the United States of America signed on April 8, 2010 the New START nuclear arms control treaty. The New START treaty replaced the lackluster SORT treaty in order to establish a nuclear agreement that would put new limits on numbers of weapons and delivery vehicles while also establishing an innovative framework for transparency and data transfer to allow confidence building between two countries that have not always seen eye-to-eye. Through academic analysis, treaty text, and four formal interviews, the context and trajectory of Russian-United States’ arms control treaties has formed to portray New START as a …

Hard Qcd Processes In The Nuclear Medium, Adam Freese

FIU Electronic Theses and Dissertations

The environment inside the atomic nucleus is one of the most fascinating arenas for the study of quantum chromodynamics (QCD). The strongly-interacting nature of the nuclear medium affects the nature of both QCD processes and the quark-gluon structure of hadrons, allowing several unique aspects of the strong nuclear force to be investigated in reactions involving nuclear targets. The research presented in this dissertation explores two aspects of nuclear QCD: firstly, the partonic structure of the nucleus itself; and secondly, the use of the nucleus as a micro-laboratory in which QCD processes can be studied.

The partonic structure of the nucleus …

The Gluex Start Counter & Beam Asymmetry $\Sigma$ In Single $\Pi^{0}$ Photoproduction, Eric J. Pooser

FIU Electronic Theses and Dissertations

The GlueX experiment aims to study meson photoproduction while utilizing the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid $\mathrm{H_{2}}$ target. A Start Counter detector was fabricated to properly identify the accelerator electron beam buckets and to provide accurate timing information. The Start Counter detector was designed to operate at photon intensities of up to $\mathrm{10^{8}\gamma/s}$ in the coherent peak and provides a timing resolution $\mathrm{\sim 300\ ps}$ so as to provide successful identification of the electron beam buckets to within 99\% accuracy. Furthermore, the Start Counter detector provides excellent solid angle …

Beam Energy Dependence Of The Third Harmonic Of Azimuthal Correlations In Au + Au Collisions At Rhic, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, D. Cebra, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au + Au collisions for energies ranging from √^s_NN = 7.7 to 200 GeV. The third harmonic υ²₃ {2} = ⟨cos3(ϕ₁−ϕ₂)⟩, where ϕ₁−ϕ₂ is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη = η₁− η₂. Nonzero υ²₃ {2} is directly related to the previously observed large-Δη narrow-Δϕ ridge correlations and …

Probing Parton Dynamics Of Qcd Matter With Ω And Φ Production, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, D. Cebra, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We present measurements of Ω and ϕ production at midrapidity from Au+Au collisions at nucleon-nucleon center-of-mass energies √^s_NN = 7.7, 11.5, 19.6, 27, and 39 GeV by the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). Motivated by the coalescence formation mechanism for these strange hadrons, we study the ratios of N (Ω^- + Ω⁻⁺) / [2N(ϕ)]. These ratios as a function of transverse momentum p_T fall on a consistent trend at high collision energies, but start to show deviations in peripheral collisions at √^s_NN = …

Centrality And Transverse Momentum Dependence Of Elliptic Flow Of Multistrange Hadrons And Φ Meson In Au + Au Collisions At √SNn = 200 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, V. Bairathi, A. Banerjee, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, D. Cebra, M. C. Cervantes, I. Chakaberia, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

We present high precision measurements of elliptic flow near midrapidity (|y| < 1.0) for multistrange hadrons and ϕ meson as a function of centrality and transverse momentum in Au + Au collisions at center of mass energy √^s_NN = 200  GeV. We observe that the transverse momentum dependence of ϕ and Ω υ₂ is similar to that of π and p, respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top …

Centrality Dependence Of Identified Particle Elliptic Flow In Relativistic Heavy Ion Collisions At √SNn = 7.7–62.4 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, X. Bai, V. Bairathi, A. Banerjee, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, D. Cebra, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

Elliptic flow (υ₂) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √^s_NN = 7.7– 62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √^s_NN = 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative υ₂ baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger υ₂ for most particles relative …

Moments Method For Shell-Model Level Density, V. Zelevinsky, M. Horoi, Roman A. Sen′Kov

Publications and Research

The modern form of the Moments Method applied to the calculation of the nuclear shell-model level density is explained and examples of the method at work are given. The calculated level density practically exactly coincides with the result of full diagonalization when the latter is feasible. The method provides the pure level density for given spin and parity with spurious center-of-mass excitations subtracted. The presence and interplay of all correlations leads to the results different from those obtained by the mean-field combinatorics.

Measurement Of Target And Double-Spin Asymmetries For The Ep → Eπ+(N) Reaction In The Nucleon Resonance Region At Low Q², Clas Collaboration, K. P. Adhikari, S E. Kuhn, D. Adikaram, M. J. Amaryan, S. Bültmann, Gail Dodge, N. Guler, L. B. Weinstein

Physics Faculty Publications

We report measurements of target- and double-spin asymmetries for the exclusive channel ^→e^→p → eπ⁺(n) in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH₃ target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3, and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low Q² range from 0.0065 to 0.35(GeV/c)². The Q² access was made possible by a custom-built Cherenkov detector …

First Measurement Of The Helicity Asymmetry E In Ƞ Photoproduction On The Proton, I. Senderovich, B.T. Morrison, M. Dugger, B.G. Ritchie, E. Pasyuk, R. Tucker, J. Brock, C. Carlin, C.D. Keith, D. G. Meekins, Y. Prok

Physics Faculty Publications

Results are presented for the first measurement of the double-polarization helicity asymmetry E for the ƞ photoproduction reaction ɣp -> ηp. Data were obtained using the FROzen Spin Target (FROST) with the CLAS spectrometer in Hall B at Jefferson Lab, covering a range of center-of-mass energy W from threshold to 2.15 GeV and a large range in center-of-mass polar angle. As an initial application of these data, the results have been incorporated into the Jülich-Bonn model to examine the case for the existence of a narrow N* resonance between 1.66 and 1.70 GeV. The addition of these data to the …

"Hammer" Events, Neutrino Energies, And Nucleon-Nucleon Correlations, L. B. Weinstein, O. Hen, Eli Piasetzky

Physics Faculty Publications

Background: Accelerator-based neutrino oscillation measurements depend on observing a difference between the expected and measured rate of neutrino-nucleus interactions at different neutrino energies or different distances from the neutrino source. Neutrino-nucleus scattering cross sections are complicated and depend on the neutrino beam energy, the neutrino-nucleus interaction, and the structure of the nucleus. Knowledge of the incident neutrino energy spectrum and neutrino-detector interactions are crucial for analyzing neutrino oscillation experiments. The ArgoNeut liquid argon time projection chamber (lArTPC) observed charged-current neutrino-argon scattering events with two protons back-to-back in the final state ("hammer" events) which they associated with short-range correlated (SRC) nucleon-nucleon …

Issues And Opportunities In Exotic Hadrons, R.A. Briceño, T. D. Cohen, S. Coito, J. J. Dudek, E. Eichten, R. E. Mitchell

Physics Faculty Publications

The last few years have been witness to a proliferation of new results concerning heavy exotic hadrons. Experimentally, many new signals have been discovered that could be pointing towards the existence of tetraquarks, pentaquarks, and other exotic configurations of quarks and gluons. Theoretically, advances in lattice field theory techniques place us at the cusp of understanding complex coupled-channel phenomena, modelling grows more sophisticated, and effective field theories are being applied to an ever greater range of situations. It is thus an opportune time to evaluate the status of the field. In the following, a series of high priority experimental and …

Laser Pulsing In Linear Compton Scattering, G. A. Krafft, E. Johnson, K. Deitrick, B. Terzić, R. Kelmar, T. Hodges, J. R. Delayen

Physics Faculty Publications

Previous work on calculating energy spectra from Compton scattering events has either neglected considering the pulsed structure of the incident laser beam, or has calculated these effects in an approximate way subject to criticism. In this paper, this problem has been reconsidered within a linear plane wave model for the incident laser beam. By performing the proper Lorentz transformation of the Klein-Nishina scattering cross section, a spectrum calculation can be created which allows the electron beam energy spread and emittance effects on the spectrum to be accurately calculated, essentially by summing over the emission of each individual electron. Such an …

Target And Beam Target Spin Asymmetries In Exclusive Π+ And Π- Electroproduction With 1.6 To 5.7 Gev Electrons, P. E. Bosted, S. Careccia, G. Dodge, S. E. Kuhn, Y. Prok, M. J. Amaryan, B. Torayev, L. B. Weinstein, Z. W. Zhao, Clas Collaboration

Physics Faculty Publications

Beam-target double-spin asymmetries and target single-spin asymmetries in exclusive π⁺ and quasiexclusive π^- electroproduction were obtained from scattering of 1.6- to 5.7-GeV longitudinally polarized electrons from longitudinally polarized protons (for π⁺) and deuterons (for π^-) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic range covered is 1.1 < W < 2.6 GeV and 0.05 < Q² < 5 GeV², with good angular coverage in the forward hemisphere. The asymmetry results were divided into approximately 40 000 kinematic bins for π⁺ from free protons and 15 000 bins for π^- production from bound nucleons in the deuteron. The …

Combining Harmonic Generation And Laser Chirping To Achieve High Spectral Density In Compton Sources, Balša Terzić, Cody Reeves, Geoffrey A. Krafft

Physics Faculty Publications

Recently various laser-chirping schemes have been investigated with the goal of reducing or eliminating ponderomotive line broadening in Compton or Thomson scattering occurring at high laser intensities. As a next level of detail in the spectrum calculations, we have calculated the line smoothing and broadening expected due to incident beam energy spread within a one-dimensional plane wave model for the incident laser pulse, both for compensated (chirped) and unchirped cases. The scattered compensated distributions are treatable analytically within three models for the envelope of the incident laser pulses: Gaussian, Lorentzian, or hyperbolic secant. We use the new results to demonstrate …

Electron-Ion Collider: The Next Qcd Frontier, A. Accardi, J. L. Albacete, M. Anselmino, N. Armesto, E. C. Aschenauer, A. Bacchetta, D. Boer, W. K. Brooks, T. Burton, N.-B. Chang, C. E. Hyde

Physics Faculty Publications

This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics over the past decades …