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Full-Text Articles in Physical Sciences and Mathematics
Rapidity-Only Tmd Factorization At One Loop, Ian Balitsky
Rapidity-Only Tmd Factorization At One Loop, Ian Balitsky
Physics Faculty Publications
Typically, a production of a particle with a small transverse momentum in hadron-hadron collisions is described by CSS-based TMD factorization at moderate Bjorken xB ~ 1 and by kT-factorization at small xB. A uniform description valid for all xB is provided by rapidity-only TMD factorization developed in a series of recent papers at the tree level. In this paper the rapidity-only TMD factorization for particle production by gluon fusion is extended to the one-loop level.
First Clas12 Measurement Of Deeply Virtual Compton Scattering Beam-Spin Asymmetries In The Extended Valence Region, G. Christiaens, M. Defurne, D. Sokhan, P. Achenbach, Z. Akbar, M. J. Amaryan, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Baashen, N. A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, A. S. Biselli, M. Zurek, Et Al., Clas Collaboration
First Clas12 Measurement Of Deeply Virtual Compton Scattering Beam-Spin Asymmetries In The Extended Valence Region, G. Christiaens, M. Defurne, D. Sokhan, P. Achenbach, Z. Akbar, M. J. Amaryan, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Baashen, N. A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, A. S. Biselli, M. Zurek, Et Al., Clas Collaboration
Physics Faculty Publications
Deeply virtual Compton scattering (DVCS) allows one to probe generalized parton distributions describing the 3D structure of the nucleon. We report the first measurement of the DVCS beam-spin asymmetry using the CLAS12 spectrometer with a 10.2 and 10.6 GeV electron beam scattering from unpolarized protons. The results greatly extend the Q2 and Bjorken-x phase space beyond the existing data in the valence region and provide 1600 new data points measured with unprecedented statistical uncertainty, setting new, tight constraints for future phenomenological studies.
Measurement Of Charged-Pion Production In Deep-Inelastic Scattering Off Nuclei With The Clas Detector, Clas Collaboration, S. Morán, R. Dupre, H. Hakobyan, Moskov J. Amaryan, Dilini Bulumulla, Mohammad Hattawy, Florian Hauenstein, Sebastian Kuhn, Pushpa Pandey, Jiwan Poudel, Yelena Prok, Lawrence B. Weinstein, N. Zachariou, J. Zhang, Z. W. Zhao, Et Al.
Measurement Of Charged-Pion Production In Deep-Inelastic Scattering Off Nuclei With The Clas Detector, Clas Collaboration, S. Morán, R. Dupre, H. Hakobyan, Moskov J. Amaryan, Dilini Bulumulla, Mohammad Hattawy, Florian Hauenstein, Sebastian Kuhn, Pushpa Pandey, Jiwan Poudel, Yelena Prok, Lawrence B. Weinstein, N. Zachariou, J. Zhang, Z. W. Zhao, Et Al.
Physics Faculty Publications
Background: Energetic quarks in nuclear deep-inelastic scattering propagate through the nuclear medium. Processes that are believed to occur inside nuclei include quark energy loss through medium-stimulated gluon bremsstrahlung and intranuclear interactions of forming hadrons. More data are required to gain a more complete understanding of these effects.
Purpose: To test the theoretical models of parton transport and hadron formation, we compared their predictions for the nuclear and kinematic dependence of pion production in nuclei.
Methods: We have measured charged-pion production in semi-inclusive deep-inelastic scattering off D, C, Fe, and Pb using the CLAS detector and the CEBAF 5.014-GeV electron beam. …
Simultaneous Monte Carlo Analysis Of Parton Densities And Fragmentation Functions, Eric Moffat, W. Melnitchouk, Ted C. Rogers, N. Sato, Jefferson Lab Angular Momentum Collaboration
Simultaneous Monte Carlo Analysis Of Parton Densities And Fragmentation Functions, Eric Moffat, W. Melnitchouk, Ted C. Rogers, N. Sato, Jefferson Lab Angular Momentum Collaboration
Physics Faculty Publications
We perform a comprehensive new Monte Carlo analysis of high-energy lepton-lepton, lepton-hadron and hadron-hadron scattering data to simultaneously determine parton distribution functions (PDFs) in the proton and parton to hadron fragmentation functions (FFs). The analysis includes all available semi-inclusive deep-inelastic scattering and single-inclusive e+e− annihilation data for pions, kaons and unidentified charged hadrons, which allows the flavor dependence of the fragmentation functions to be constrained. Employing a new multistep fitting strategy and more flexible parametrizations for both PDFs and FFs, we assess the impact of different datasets on sea quark densities and confirm the previously observed suppression …
Neutron Valence Structure From Nuclear Deep Inelastic Scattering, E. P. Segarra, A. Schmidt, T. Kutz, D. W. Higinbotham, E. Piasetzky, M. Strikman, L. B. Weinstein, O. Hen
Neutron Valence Structure From Nuclear Deep Inelastic Scattering, E. P. Segarra, A. Schmidt, T. Kutz, D. W. Higinbotham, E. Piasetzky, M. Strikman, L. B. Weinstein, O. Hen
Physics Faculty Publications
Mechanisms of spin-flavor SU(6) symmetry breaking in quantum chromodynamics (QCD) are studied via an extraction of the free neutron structure function from a global analysis of deep inelastic scattering (DIS) data on the proton and on nuclei from A = 2 (deuterium) to 208 (lead). Modification of the structure function of nucleons bound in atomic nuclei (known as the EMC effect) are consistently accounted for within the framework of a universal modification of nucleons in short-range correlated (SRC) pairs. Our extracted neutron-to-proton structure function ratio Fn2/Fp2 becomes constant for xB ≥ 0.6, equaling 0.47 …
Nlo Evolution Of 3-Quark Wilson Loop Operator, I. Balitsky, A. V. Grabovsky
Nlo Evolution Of 3-Quark Wilson Loop Operator, I. Balitsky, A. V. Grabovsky
Physics Faculty Publications
It is well known that the high-energy scattering of a meson from some hadronic target can be described by the interaction of that target with a color dipole formed by two Wilson lines corresponding to the fast quark-antiquark pair. Moreover, the energy dependence of the scattering amplitude is governed by the evolution equation of this color dipole with respect to rapidity. Similarly, the energy dependence of scattering of a baryon can be described in terms of evolution of a three-Wilson-line operator with respect to the rapidity of the Wilson lines. We calculated the evolution of the 3-quark Wilson loop operator …
Transverse Momentum Dependent (Tmd) Parton Distribution Functions: Status And Prospects, R. Angeles-Martinez, A. Bacchetta, I. I. Balitsky, D. Boer, M. Boglione, R. Boussarie, F. A. Ceccopieri, I. O. Cherednikov, P. Connor, M. G. Echevarria, G. Ferrera, J. Grados Luyando, F. Hautmann, H. Jung, T. Kasemets, K. Kutak, J. P. Lansberg, A. Lelek, G. Lykasov, J. D. Madrigal Martinez, P. J. Mulders, E. R. Nocera, E. Petreska, C. Pisano, R. Plaċakyte, V. Radescu, M. Radici, G. Schnell, I. Scimemi, A. Signori, L. Szymanowski, S. Taheri Monfared, F.F. Van Der Veken, H. J. Van Haevermaet, P. Van Mechelen, A. A. Vladimirov, S. Wallon
Transverse Momentum Dependent (Tmd) Parton Distribution Functions: Status And Prospects, R. Angeles-Martinez, A. Bacchetta, I. I. Balitsky, D. Boer, M. Boglione, R. Boussarie, F. A. Ceccopieri, I. O. Cherednikov, P. Connor, M. G. Echevarria, G. Ferrera, J. Grados Luyando, F. Hautmann, H. Jung, T. Kasemets, K. Kutak, J. P. Lansberg, A. Lelek, G. Lykasov, J. D. Madrigal Martinez, P. J. Mulders, E. R. Nocera, E. Petreska, C. Pisano, R. Plaċakyte, V. Radescu, M. Radici, G. Schnell, I. Scimemi, A. Signori, L. Szymanowski, S. Taheri Monfared, F.F. Van Der Veken, H. J. Van Haevermaet, P. Van Mechelen, A. A. Vladimirov, S. Wallon
Physics Faculty Publications
We review transverse momentum dependent (TMD) parton distribution functions, their application to topical issues in high-energy physics phenomenology, and their theoretical connections with QCD resummation, evolution and factorization theorems. We illustrate the use of TMDs via examples of multi-scale problems in hadronic collisions. These include transverse momentum qT spectra of Higgs and vector bosons for low qT, and azimuthal correlations in the production of multiple jets associated with heavy bosons at large jet masses. We discuss computational tools for TMDs, and present the application of a new tool, TMDLIB, to parton density fits and parameterizations.
Quark Contribution To The Small-𝔁 Evolution Of Color Dipole, Ian Balitsky
Quark Contribution To The Small-𝔁 Evolution Of Color Dipole, Ian Balitsky
Physics Faculty Publications
The small-𝔁 deep inelastic scattering in the saturation region is governed by the nonlinear evolution of Wilson-lines operators. In the leading logarithmic approximation it is given by the Balitsky-Kovchegov (BK) equation for the evolution of color dipoles. In the next-to-leading order (NLO) the nonlinear equation gets contributions from quark and gluon loops. In this paper I calculate the quark-loop contribution to small-𝔁 evolution of Wilson lines in the NLO. It turns out that there are no new operators at the one-loop level—just as at the tree level, the high-energy scattering can be described in terms of Wilson lines. In addition, …
Global Analysis Of Data On The Proton Structure Function G₁ And The Extraction Of Its Moments, M. Osipenko, S. Simula, W. Melnitchouk, P. Bosted, V. Burkert, E. Christy, K. Griffioen, C. Keppel, S. Kuhn, G. Ricco
Global Analysis Of Data On The Proton Structure Function G₁ And The Extraction Of Its Moments, M. Osipenko, S. Simula, W. Melnitchouk, P. Bosted, V. Burkert, E. Christy, K. Griffioen, C. Keppel, S. Kuhn, G. Ricco
Physics Faculty Publications
Inspired by recent measurements with the CLAS detector at Jefferson Lab, we perform a self-consistent analysis of world data on the proton structure function g1 in the range 0.17 < Q2 < 30 (GeV/c)2. We compute for the first time low-order moments of g, and study their evolution from small to large values of Q2. The analysis includes the latest data on both the unpolarized inclusive cross sections and the ratio R = σ L/σT from Jefferson Lab, as well as a new model for the transverse asymmetry A2 in the resonance region. The contributions of …
Higher Twist Analysis Of The Proton G₁ Structure Function, M. Osipenko, W. Melnitchouk, S. Simula, P. Bosted, V. Burkert, M. E. Christy, K. Griffioen, C. Keppel, S. E. Kuhn
Higher Twist Analysis Of The Proton G₁ Structure Function, M. Osipenko, W. Melnitchouk, S. Simula, P. Bosted, V. Burkert, M. E. Christy, K. Griffioen, C. Keppel, S. E. Kuhn
Physics Faculty Publications
We perform a global analysis of all available spin-dependent proton structure function data, covering a large range of Q2, 1 ⩽ Q2 ⩽ 30 GeV2, and calculate the lowest moment of the g1 structure function as a function of Q2. From the Q2 dependence of the lowest moment we extract matrix elements of twist-4 operators, and determine the color electric and magnetic polarizabilities of the proton to be XE= 0.026 ± 0.015(stat) ± 0.0210.024 (sys) and XB= -0.013 ∓ 0.007(stat) ∓ 0.010 0.012(sys), respectively.
Experimental Determination Of The Evolution Of The Bjorken Integral At Low Q², A. Deur, P. Bosted, V. Burkert, G. Cates, J.P. Chen, Seonho Choi, D. Crabb, C.W. De Jager, R. De Vita, G.E. Dodge, R. Fatemi, T.A. Forest, F. Garibaldi, R. Gilman, E. W. Hughes, X. Jiang, W. Korsch, S. E. Kuhn, W. Melnitchouk, Z.-E. Meziani, R. Minehart, A.V. Skabelin, K. Slifer, M. Taiuti, J. Yun
Experimental Determination Of The Evolution Of The Bjorken Integral At Low Q², A. Deur, P. Bosted, V. Burkert, G. Cates, J.P. Chen, Seonho Choi, D. Crabb, C.W. De Jager, R. De Vita, G.E. Dodge, R. Fatemi, T.A. Forest, F. Garibaldi, R. Gilman, E. W. Hughes, X. Jiang, W. Korsch, S. E. Kuhn, W. Melnitchouk, Z.-E. Meziani, R. Minehart, A.V. Skabelin, K. Slifer, M. Taiuti, J. Yun
Physics Faculty Publications
We extract the Bjorken integral 𝚪1p-n in the range 0.17 < Q2 <1.10 GeV2 from inclusive scattering of polarized electrons by polarized protons, deuterons, and 3He, for the region in which the integral is dominated by nucleon resonances. These data bridge the domains of the hadronic and partonic descriptions of the nucleon. In combination with earlier measurements at higher Q2, we extract the nonsinglet twist-4 matrix element f2.
Measurement Of Inclusive Spin Structure Functions Of The Deuteron, J. Yun, S. E. Kuhn, G. E. Dodge, T. A. Forest, M. Bektasoglu, L. Ciciani, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, L. M. Qin, S. Stepanyan, L. B. Weinstein, Et Al., Clas Collaboration
Measurement Of Inclusive Spin Structure Functions Of The Deuteron, J. Yun, S. E. Kuhn, G. E. Dodge, T. A. Forest, M. Bektasoglu, L. Ciciani, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, L. M. Qin, S. Stepanyan, L. B. Weinstein, Et Al., Clas Collaboration
Physics Faculty Publications
We report the results of a new measurement of spin structure functions of the deuteron in the region of moderate momentum transfer [Q2 = 0.27-1.3 (GeV/c)2] and final hadronic state mass in the nucleon resonance region (W=1.08-2.0 GeV). We scattered a 2.5 GeV polarized continuous electron beam at Jefferson Lab off a dynamically polarized cryogenic solid state target (15ND3) and detected the scattered electrons with the CEBAF large acceptance spectrometer. From our data, we extract the longitudinal double spin asymmetry A∥ and the spin structure function g1d. Our data are …
Deeply Virtual Compton Scattering At Small X, Ian Balitsky, Elena Kuchina
Deeply Virtual Compton Scattering At Small X, Ian Balitsky, Elena Kuchina
Physics Faculty Publications
We calculate the cross section of deeply virtual Compton scattering at large energies and intermediate momentum transfers.