Physics Commons^™

First Use Of A Longitudinally Polarized Target With Clas12, C. D. Keith, J. Brock, C. Carlin, T. Kageya, V. Lagerquist, J. Maxwell, P. Pandey

Physics Faculty Publications

Run Group C comprises eight experiments utilizing the CLAS12 detector system in Hall B at Jefferson Lab to study the multidimensional partonic structure of nucleons. The experiments scatter electrons from polarized protons and neutrons in samples of solid NH3 and ND3, dynamically polarized at a temperature of 1 K in a 5 T magnetic field. After a brief description of the target system, the current status of the target and preliminary results of its performance in the experiment are presented.

Observation Of Correlations Between Spin And Transverse Momenta In Back-To-Back Dihadron Production At Clas12, H. Avakian, T.B. Hayward, A. Kotzinian, W.R. Armstrong, H. Atac, C. Ayerbe Gayoso, L. Baashen, N.A. Balzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, L. Biondo, A. S. Biselli, M. Bondi, S. Boiarinov, M. Zurek, Et Al.

Physics Faculty Publications

We report the first measurements of deep inelastic scattering spin-dependent azimuthal asymmetries in back-to-back dihadron electroproduction in the deep inelastic scattering process. In this reaction, two hadrons are produced in opposite hemispheres along the z axis in the virtual photon-target nucleon center-of-mass frame, with the first hadron produced in the current-fragmentation region and the second in the target-fragmentation region. The data were taken with longitudinally polarized electron beams of 10.2 and 10.6 GeV incident on an unpolarized liquid-hydrogen target using the CLAS12 spectrometer at Jefferson Lab. Observed nonzero sinΔϕ modulations in ep→e'pπ⁺ X events, where Δϕ is the difference …

Two-Point Correlator Of Twist-2 Light-Ray Operators In N=Sym In Bfkl Approximation, Ian Balitsky, Vladimir Kazakov, Evgeny Sobko

Physics Faculty Publications

We generalize local operators of the leading twist-2 of 𝒩 = SYM theory to the case of complex Lorentz spin j using principal series representation of sl(2, R). We give the direct computation of correlation function of two such non-local operators in the BFKL regime when j → 1. The correlator appears to have the expected conformal coordinate dependence governed by the anomalous dimension of twist-2 operator in NLO BFKL approximation predicted by Kotikov and Lipatov.

Gluon Transverse-Momentum-Dependent Distributions From Large-Momentum Effective Theory, Ruilin Zhu, Yao Ji, Jian-Hui Zhang, Shuai Zhao

Physics Faculty Publications

We demonstrate that gluon transverse-momentum-dependent parton distribution functions (TMDPDFs) can be extracted from lattice calculations of appropriate Euclidean correlations in large-momentum effective theory (LaMET). Based on perturbative calculations of gluon unpolarized and helicity TMDPDFs, we present a matching formula connecting them and their LaMET counterparts, where the latter are renormalized in a scheme facilitating lattice calculations and converted to the MS ¯ scheme. The hard matching kernel is given up to one-loop level. We also show that the perturbative result is independent of the prescription used for the pinch-pole singularity in the relevant correlations. Our results offer a guidance for …

Prospects For 𝛾*𝛾* → 𝜋𝜋 Via Lattice Qcd, Raúl Briceño, Andrew W. Jackura, Arkaitz Rodas, Juan V. Guerrero

Physics Faculty Publications

The 𝛾*𝛾* → 𝜋𝜋 scattering amplitude plays a key role in a wide range of phenomena, including understanding the inner structure of scalar resonances as well as constraining the hadronic contributions to the anomalous magnetic moment of the muon. In this work, we explain how the infinite-volume Minkowski amplitude can be constrained from finite-volume Euclidean correlation functions. The relationship between the finite-volume Euclidean correlation functions and the desired amplitude holds up to energies where 3𝜋 states can go on shell, and is exact up to exponentially small corrections that scale like 𝒪(e^−m𝜋L), where L is the spatial extent …

Determination Of The Titanium Spectral Function From (E, E'P) Data, L. Jiang, A.M. Ankowski, D. Abrams, L. Gu, B. Aljawrneh, S. Alsalmi, J. Bane, A. Batz, S. Barcus, M. Barroso, V. Bellini, O. Benhar, J. Bericic, D. Biswas, A. Camsonne, J. Castellanos, J. -P. Chen, M. E. Christy, K. Craycraft, R. Cruz-Torres, H. Dai, D. Day, A. Dirican, S. -C. Dusa, E. Fuchey, T. Gautam, C. Giusti, J. Gomez, C. Gu, T. J. Hague, J. -O. Hansen, F. Hauenstein, D. W. Higinbotham, C. Hyde, Z. Jerzyk, A. M. Johnson, C. Keppel, C. Lanham, S. Li, R. Lindgren, H. Liu, C. Mariani, R. E. Mcclellan, D. Meekins, R. Michaels, M. Mihovilovic, M. Murphy, D. Nguyen, M. Nycz, L. Ou, B. Pandey, V. Pandey, K. Park, G. Perera, A.J.R. Puckett, S.N. Santiesteban, S. Ŝirca, T. Su, L. Tang, Y. Tian, N. Ton, B. Wojsekhowski, S. Wood, Z. Ye, J. Zhang

Physics Faculty Publications

The E12-14-012 experiment, performed in Jefferson Lab Hall A, has measured the (e,e′p) cross section in parallel kinematics using a natural titanium target. In this paper, we report the analysis of the dataset obtained in different kinematics for our solid natural titanium target. Data were obtained in a range of missing momentum and missing energy between 15 ≲ p_m ≲ 250  MeV/c and 12 ≲ Em ≲ 80  MeV, respectively, and using an electron beam energy of 2.2 GeV. We measured the reduced cross section with ∼7% accuracy as a function of both missing momentum and missing energy. …

Three-Body Scattering And Quantization Conditions From S-Matrix Unitarity, Andrew W. Jackura

Physics Faculty Publications

Two methodologies have been presented in the literature which connect relativistic three-particle scattering amplitudes with lattice QCD spectra—the “relativistic effective field theory” approach and the “finite-volume unitarity” method. While both methods have been shown to be equivalent in various works, it has not been shown how to arrive at the relativistic effective field theory results directly from S-matrix unitarity. In this work, we provide a simple proof of the relativistic effective field theory form of the scattering equations directly from unitarity. Motivated by the finite-volume unitarity approach, we then postulate a set of quantization conditions which relate the finite-volume energy …

Measurement Of Spin-Density Matrix Elements In P(770) Production With A Linearly Polarized Photon Beam At E𝛾 = 8.2-8.8 Gev, S. Adhikari, F. Afzal, C. S. Akondi, M. Albrecht, M. Amaryan, V. Arroyave, A. Asaturyan, A. Austregesilo, Z. Baldwin, F. Barbosa, J. Barlow, E. Barriga, R. Barsotti, T. D. Beattie, V. V. Berdnikov, T. Black, W. Boeglin, W. J. Briscoe, T. Britton, B. Zihlmann, Et Al., Gluex Collaboration

Physics Faculty Publications

The GlueX experiment at Jefferson Lab studies photoproduction of mesons using linearly polarized 8.5 GeV photons impinging on a hydrogen target which is contained within a detector with near-complete coverage for charged and neutral particles. We present measurements of spin-density matrix elements for the photoproduction of the vector meson ρ(770). The statistical precision achieved exceeds that of previous experiments for polarized photoproduction in this energy range by orders of magnitude. We confirm a high degree of s-channel helicity conservation at small squared four-momentum transfer t and are able to extract the t dependence of natural- and unnatural-parity exchange contributions to …

Toward A Generative Modeling Analysis Of Clas Exclusive 2𝜋 Photoproduction, T. Alghamdi, Y. Alanazi, M. Battaglieri, Ł. Bibrzycki, A. V. Golda, A. N. Hiller Blin, E. L. Isupov, Y. Li, L. Marsicano, W. Melnitchouk, V. I. Mokeev, G. Montaña, A. Pilloni, N. Sato, A. P. Szczepaniak, T. Vittorini

Computer Science Faculty Publications

AI-supported algorithms, particularly generative models, have been successfully used in a variety of different contexts. This work employs a generative modeling approach to unfold detector effects specifically tailored for exclusive reactions that involve multiparticle final states. Our study demonstrates the preservation of correlations between kinematic variables in a multidimensional phase space. We perform a full closure test on two-pion photoproduction pseudodata generated with a realistic model in the kinematics of the Jefferson Lab CLAS g11 experiment. The overlap of different reaction mechanisms leading to the same final state associated with the CLAS detector’s nontrivial effects represents an ideal test case …

Fourier Acceleration In The Linear Sigma Model, Cameron Cianci

Honors Scholar Theses

The linear sigma model is a low energy effective model of Quantum Chromodynamics. This model mimics the breaking of chiral symmetry both spontaneously and explicitly through the quark condensate and pion mass matrix respectively. Fourier acceleration is a method that can be implemented in the Hybrid Monte-Carlo algorithm which decreases autocorrelations due to critical slowing down through tuning the mass parameters in the HMC algorithm. Fourier acceleration is applied to the linear sigma model with a novel mass estimation procedure, by assuming the modes behave approximately like simple harmonic oscillators. The masses are chosen by sampling the expectation values of …

A Mode-Sum Prescription For The Renormalized Stress Energy Tensor On Black Hole Spacetimes, Peter Taylor, Cormac Breen, Adrian Ottewill

Articles

In this paper, we describe an extremely efficient method for computing the renormalized stress-energy tensor of a quantum scalar field in spherically symmetric black hole spacetimes. The method applies to a scalar field with arbitrary field parameters. We demonstrate the utility of the method by computing the renormalized stress-energy tensor for a scalar field in the Schwarzschild black hole spacetime, applying our results to discuss the null energy condition and the semiclassical backreaction.

Search For A W' Boson Decaying To A Vector-Like Quark And A Top Or Bottom Quark In The All-Jets Final State At √S = 13 Tev, The Cms Collaboration

Department of Physics and Astronomy: Faculty Publications

A search is presented for a heavy W0 boson resonance decaying to a B or T vector-like quark and a t or a b quark, respectively. The analysis is performed using protonproton collisions collected with the CMS detector at the LHC. The data correspond to an integrated luminosity of 138 fb⁻¹ at a center-of-mass energy of 13TeV. Both decay channels result in a signature with a t quark, a Higgs or Z boson, and a b quark, each produced with a significant Lorentz boost. The all-hadronic decays of the Higgs or Z boson and of the t quark are …

Qcd Corrections In Tqγ Production At Hadron Colliders, Nikolaos Kidonakis, Nodoka Yamanaka

Faculty and Research Publications

We study QCD corrections for the associated production of a single top quark and a photon (tqγ production) at hadron colliders. We calculate the NLO cross section at LHC and future collider energies for a variety of kinematical cuts, and we estimate uncertainties from scale dependence and from parton distributions. We also calculate differential distributions in top-quark transverse-momentum and rapidity as well as photon energy. Finally, we study higher-order corrections from soft-gluon emission for this process, and we provide approximate NNLO (aNNLO) results for the cross section and top-quark differential distributions. We also compare our calculations with recent measurements from …

Fermion-Induced Electroweak Symmetry Non-Restoration Via Temperature-Dependent Masses, Yu Hang Ng

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Standard Model (SM) and many extensions of SM predict that the electroweak (EW) symmetry was restored in the early universe when the temperature was around 160 GeV. However, recent studies showed that the interactions between some new scalars and SU(2)_L Higgs doublet(s) can cause the EW symmetry to remain broken at temperatures well above the EW scale in certain renormalizable extensions of SM. In this study, we found that new fermions from renormalizable models can also induce this EW symmetry non-restoration effect, provided that they have the appropriate temperature-dependent masses. These masses can arise naturally from the interactions between the …

What Is A Photon? Foundations Of Quantum Field Theory, Charles G. Torre

All Physics Faculty Publications

This is a brief, informal, and relatively low-level course on the foundations of quantum field theory. The prerequisites are undergraduate courses in quantum mechanics and electromagnetism.

Using Z Boson Events To Study Parton-Medium Interactions In Pb-Pb Collisions, The Cms Collaboration, A. M. Sirunyan, A. Tumasyan, W. Adam, F. Ambrogi, T. Bergauer, Julie M. Hogan

Physics and Engineering Faculty Publications

The spectra measurements of charged hadrons produced in the shower of a parton originating in the same hard scattering with a leptonically decaying Z boson are reported in lead-lead nuclei (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Both Pb-Pb and pp data sets are recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 1.7 nb-1 and 320 pb-1, respectively. Hadronic collision data with one reconstructed Z boson candidate with the transverse momentum pT>30 GeV/c are analyzed. The Z boson constrains the initial energy and direction of the …

Search For Wγ Resonances In Proton-Proton Collisions At S=13 Tev Using Hadronic Decays Of Lorentz-Boosted W Bosons, The Cms Collaboration, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, Julie M. Hogan

Physics and Engineering Faculty Publications

A search for Wγ resonances in the mass range between 0.7 and 6.0 TeV is presented. The W boson is reconstructed via its hadronic decays, with the final-state products forming a single large-radius jet, owing to a high Lorentz boost of the W boson. The search is based on proton-proton collision data at s=13 TeV, corresponding to an integrated luminosity of 137 fb−1, collected with the CMS detector at the LHC in 2016–2018. The Wγ mass spectrum is parameterized with a smoothly falling background function and examined for the presence of resonance-like signals. No significant excess above the predicted background …

Erratum: Search For Heavy Higgs Bosons Decaying To A Top Quark Pair In Proton-Proton Collisions At S = 13 Tev (Journal Of High Energy Physics, (2020), 2020, 4, (171), 10.1007/Jhep04(2020)171), The Cms Collaboration, A. M. Sirunyan, A. Tumasyan, W. Adam, F. Ambrogi, T. Bergauer, Julie M. Hogan

Physics and Engineering Faculty Publications

In figure 7 of the original publication, the label of the y axis should have been (Formula presented.)”. The corrected version is shown in figure 1. Accordingly, the text pointing to the figure should read “figure 7 shows scans of (Formula presented.) for this hypothesis, as a function of the coupling modifier gAtt-”.

Measurement Of W±Γ Differential Cross Sections In Proton-Proton Collisions At S =13 Tev And Effective Field Theory Constraints, The Cms Collaboration, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, Julie M. Hogan

Physics and Engineering Faculty Publications

Differential cross section measurements of W±γ production in proton-proton collisions at s=13 TeV are presented. The data set used in this study was collected with the CMS detector at the CERN LHC in 2016-2018 with an integrated luminosity of 138 fb-1. Candidate events containing an electron or muon, a photon, and missing transverse momentum are selected. The measurements are compared with standard model predictions computed at next-to-leading and next-to-next-to-leading orders in perturbative quantum chromodynamics. Constraints on the presence of TeV-scale new physics affecting the WWγ vertex are determined within an effective field theory framework, focusing on the O3W operator. A …

Study Of Dijet Events With Large Rapidity Separation In Proton-Proton Collisions At √S = 2.76 Tev, The Cms Collaboration, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, Julie M. Hogan

Physics and Engineering Faculty Publications

The cross sections for inclusive and Mueller-Navelet dijet production are measured as a function of the rapidity separation between the jets in proton-proton collisions at s = 2.76 TeV for jets with transverse momentum pT> 35 GeV and rapidity |y| < 4.7. Various dijet production cross section ratios are also measured. A veto on additional jets with pT> 20 GeV is introduced to improve the sensitivity to the effects of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution. The measurement is compared with the predictions of various Monte Carlo models based on leading-order and next-to-leading-order calculations including the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi leading-logarithm (LL) parton shower as well as the LL BFKL resummation. [Figure not available: see fulltext.]

Isolated Objects And Their Evolution: A Derivation Of The Propagator’S Path Integral For Spinless Elementary Particles, Domenico Napoletani, Daniele Carlo Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

We formalize the notion of isolated objects (units), and we build a consistent theory to describe their evolution and interaction. We further introduce a notion of indistinguishability of distinct spacetime paths of a unit, for which the evolution of the state variables of the unit is the same, and a generalization of the equivalence principle based on indistinguishability. Under a time reversal condition on the whole set of indistinguishable paths of a unit, we show that the quantization of motion of spinless elementary particles in a general potential field can be derived in this framework, in the limiting …

A New Non-Inheriting Homogeneous Solution Of The Einstein-Maxwell Equations With Cosmological Term, Charles G. Torre

Research Vignettes

No abstract provided.

Measuring Recoiling Nucleons From The Nucleus With The Future Electron Ion Collider, Florian Hauenstein, A. Jentsch, J. R. Pybus, A. Kiral, M. D. Baker, Y. Furletova, O. Hen, D. W. Higinbotham, Charles Hyde, V. Morozov, D. Romanov, Lawrence B. Weinstein

Physics Faculty Publications

Short range correlated nucleon-nucleon (NN) pairs are an important part of the nuclear ground state. They are typically studied by scattering an electron from one nucleon in the pair and detecting its spectator correlated partner (“spectator-nucleon tagging”). The Electron Ion Collider (EIC) should be able to detect these nucleons, since they are boosted to high momentum in the laboratory frame by the momentum of the ion beam. To determine the feasibility of these studies with the planned EIC detector configuration, we have simulated quasielastic scattering for two electron and ion beam energy configurations: 5 GeV e− and 41 …

Measurement Of Spin Density Matrix Elements In Λ(1520) Photoproduction At 8.2-8.8 Gev, Shankar Adhikari, C. S. Akondi, M. Albrecht, Moskov Amaryan, Tyler Viducic, B. Zihlmann, Et Al., Gluex Collaboration, D. I. Glazier, V. Mathieu

Physics Faculty Publications

We report on the measurement of spin density matrix elements of the Λ(1520) in the photoproduction reaction γp→Λ(1520)K⁺, via its subsequent decay to K⁻p. The measurement was performed as part of the GlueX experimental program in Hall D at Jefferson Laboratory using a linearly polarized photon beam with E_γ = 8.2 GeV–8.8 GeV. These are the first such measurements in this photon energy range. Results are presented in bins of momentum transfer squared, − (t − t₀). We compare the results with a Reggeon exchange model and determine that natural exchange amplitudes are …

Nonlinear Meissner Effect In Nb3Sn Coplanar Resonators, Junki Makita, C. Sundahl, Gianluigi Ciovati, C. B. Eom, Alex Gurevich

Physics Faculty Publications

We investigated the nonlinear Meissner effect (NLME) in Nb₃Sn thin-film coplanar resonators by measuring the resonance frequency as a function of a parallel magnetic field at different temperatures. We used low rf power probing in films thinner than the London penetration depth λ(B) to significantly increase the field onset of vortex penetration and measure the NLME under equilibrium conditions. Contrary to the conventional quadratic increase of λ(B) with B expected in s-wave superconductors, we observed a nearly linear increase of the penetration depth with B. We concluded that this behavior of λ(B) is due to weak linked grain …

Connecting Matrix Elements To Multi-Hadron Form-Factors, Andrew W. Jackura

Physics Faculty Publications

We discuss developments in calculating multi-hadron form-factors and transition processes via lattice QCD. Our primary tools are finite-volume scaling relations, which map spectra and matrix elements to the corresponding multi-hadron infinite-volume amplitudes. We focus on two hadron processes probed by an external current, and provide various checks on the finite-volume formalism in the limiting cases of perturbative interactions and systems forming a bound state. By studying model-independent properties of the infinite-volume amplitudes, we are able to rigorously define form-factors of resonances.

Determination Of The Argon Spectral Function From (E, E'P) Data, Jefferson Lab Hall A Collaboration, L. Jiang, A.M. Ankowski, D. Abrams, Florian Hauenstein, Charles Hyde, S. Wood, Z. Ye, J. Zhang, Et Al.

Physics Faculty Publications

The E12-14-012 experiment, performed in Jefferson Lab Hall A, has measured the (e,e′p) cross section in parallel kinematics using a natural argon target. Here, we report the full results of the analysis of the data set corresponding to beam energy 2.222 GeV, and spanning the missing momentum and missing energy range 15 ≲ pm ≲ 300  MeV /c and 12 ≲ Em ≲ 80  MeV. The reduced cross section, determined as a function of p_m and E_m with ≈ 4% accuracy, has been fitted using the results of Monte Carlo simulations involving a model spectral function and …

The Differentialgeometry Package, Ian M. Anderson, Charles G. Torre

Downloads

This is the entire DifferentialGeometry package, a zip file (DifferentialGeometry.zip) containing (1) a Maple Library file, DifferentialGeometryUSU.mla, (2) a Maple help file DifferentialGeometry.help, (3) a Maple Library file, DGApplicatons.mla. This is the latest version of the DifferentialGeometry software; it supersedes what is released with Maple.

Installation instructions

Reply To "Comment On 'Quasielastic Lepton Scattering And B=Back-To-Back Nucleons In The Short-Time Approximation' ", S. Pastore, J. Carlson, Rocco Schiavilla, J. L. Barrow, S. Gandolfi, R. B. Wiringa

Physics Faculty Publications

We briefly review the concept of scaling and how it occurs in quasielastic electron and neutrino scattering from nuclei, and then the particular approach to scaling in the short-time approximation. We show that, whereas two-nucleon currents do significantly enhance the transverse electromagnetic response, they do not spoil scaling, but, in fact, enhance it. We provide scaling results obtained in the short-time approximation that verify this claim. The enhanced scaling, although obtained empirically, is not “accidental”—as claimed in [O. Benhar, Phys. Rev. C 105, 049801 (2022)]—but rather reflects quasielastic kinematics and the dominant role played by pion-exchange interactions and currents …

Accessing Scattering Amplitudes Using Quantum Computers, Raúl A. Briceño, Marco A. Carrillo, Juan V. Guerrero, Maxwell T. Hansen, Alexandru M. Sturzu

Physics Faculty Publications

Future quantum computers may serve as a tool to access non-perturbative real-time correlation functions. In this talk, we discuss the prospects of using these to study Compton scattering for arbitrary kinematics. The restriction to a finite-volume spacetime, unavoidable in foreseeable quantum-computer simulations, must be taken into account in the formalism for extracting scattering observables. One approach is to work with a non-zero iϵ-prescription in the Fourier transform to definite momentum and then to estimate an ordered double limit, in which the spacetime volume is sent to infinity before ϵ is sent to 0. For the amplitudes and parameters considered here, …