Search

Your search keyword '"Meekins D"' showing total 8 results
Start Over Author "Meekins D" Database Supplemental Index
8 results on '"Meekins D"'

1. Determining the gluonic gravitational form factors of the proton

Author

Duran, B., Meziani, Z.-E., Joosten, S., Jones, M. K., Prasad, S., Peng, C., Armstrong, W., Atac, H., Chudakov, E., Bhatt, H., Bhetuwal, D., Boer, M., Camsonne, A., Chen, J.-P., Dalton, M. M., Deokar, N., Diefenthaler, M., Dunne, J., El Fassi, L., Fuchey, E., Gao, H., Gaskell, D., Hansen, O., Hauenstein, F., Higinbotham, D., Jia, S., Karki, A., Keppel, C., King, P., Ko, H. S., Li, X., Li, R., Mack, D., Malace, S., McCaughan, M., McClellan, R. E., Michaels, R., Meekins, D., Paolone, Michael, Pentchev, L., Pooser, E., Puckett, A., Radloff, R., Rehfuss, M., Reimer, P. E., Riordan, S., Sawatzky, B., Smith, A., Sparveris, N., Szumila-Vance, H., Wood, S., Xie, J., Ye, Z., Yero, C., and Zhao, Z.

Abstract

The proton is one of the main building blocks of all visible matter in the Universe1. Among its intrinsic properties are its electric charge, mass and spin2. These properties emerge from the complex dynamics of its fundamental constituents—quarks and gluons—described by the theory of quantum chromodynamics3–5. The electric charge and spin of protons, which are shared among the quarks, have been investigated previously using electron scattering2. An example is the highly precise measurement of the electric charge radius of the proton6. By contrast, little is known about the inner mass density of the proton, which is dominated by the energy carried by gluons. Gluons are hard to access using electron scattering because they do not carry an electromagnetic charge. Here we investigated the gravitational density of gluons using a small colour dipole, through the threshold photoproduction of the J/ψparticle. We determined the gluonic gravitational form factors of the proton7,8from our measurement. We used a variety of models9–11and determined, in all cases, a mass radius that is notably smaller than the electric charge radius. In some, but not all cases, depending on the model, the determined radius agrees well with first-principle predictions from lattice quantum chromodynamics12. This work paves the way for a deeper understanding of the salient role of gluons in providing gravitational mass to visible matter.

Published
2023
Full Text
View/download PDF

2. Revealing the short-range structure of the mirror nuclei 3H and 3He

Author

Li, S., Cruz-Torres, R., Santiesteban, N., Ye, Z. H., Abrams, D., Alsalmi, S., Androic, D., Aniol, K., Arrington, J., Averett, T., Gayoso, C. Ayerbe, Bane, J., Barcus, S., Barrow, J., Beck, A., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Bulumulla, D., Camsonne, A., Castellanos, J., Chen, J., Chen, J.-P., Chrisman, D., Christy, M. E., Clarke, C., Covrig, S., Craycraft, K., Day, D., Dutta, D., Fuchey, E., Gal, C., Garibaldi, F., Gautam, T. N., Gogami, T., Gomez, J., Guèye, P., Habarakada, A., Hague, T. J., Hansen, J. O., Hauenstein, F., Henry, W., Higinbotham, D. W., Holt, R. J., Hyde, C., Itabashi, T., Kaneta, M., Karki, A., Katramatou, A. T., Keppel, C. E., Khachatryan, M., Khachatryan, V., King, P. M., Korover, I., Kurbany, L., Kutz, T., Lashley-Colthirst, N., Li, W. B., Liu, H., Liyanage, N., Long, E., Mammei, J., Markowitz, P., McClellan, R. E., Meddi, F., Meekins, D., Beck, S. Mey-Tal, Michaels, R., Mihovilovič, M., Moyer, A., Nagao, S., Nelyubin, V., Nguyen, D., Nycz, M., Olson, M., Ou, L., Owen, V., Palatchi, C., Pandey, B., Papadopoulou, A., Park, S., Paul, S., Petkovic, T., Pomatsalyuk, R., Premathilake, S., Punjabi, V., Ransome, R. D., Reimer, P. E., Reinhold, J., Riordan, S., Roche, J., Rodriguez, V. M., Schmidt, A., Schmookler, B., Segarra, E. P., Shahinyan, A., Slifer, K., Solvignon, P., Širca, S., Su, T., Suleiman, R., Szumila-Vance, H., Tang, L., Tian, Y., Tireman, W., Tortorici, F., Toyama, Y., Uehara, K., Urciuoli, G. M., Votaw, D., Williamson, J., Wojtsekhowski, B., Wood, S., Zhang, J., and Zheng, X.

Abstract

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon–nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure1–3, and mapping out the strength and the isospin structure (neutron–proton (np) versus proton–proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements3–5. Two-nucleon knockout or ‘triple coincidence’ reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements6–8have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon–nucleon interaction.

Published
2022
Full Text
View/download PDF

3. Proton spin structure and generalized polarizabilities in the strong quantum chromodynamics regime

Author

Ruth, D., Zielinski, R., Gu, C., Allada (Cummings), M., Badman, T., Huang, M., Liu, J., Zhu, P., Allada, K., Zhang, J., Camsonne, A., Chen, J.-P., Slifer, K., Aniol, K., Annand, J., Arrington, J., Averett, T., Baghdasaryan, H., Bellini, V., Boeglin, W., Brock, J., Carlin, C., Chen, C., Cisbani, E., Crabb, D., Daniel, A., Day, D., Duve, R., Fassi, L. El, Friedman, M., Fuchey, E., Gao, H., Gilman, R., Glamazdin, S., Gueye, P., Hafez, M., Han, Y., Hansen, O., Shabestari, M. Hashemi, Hen, O., Higinbotham, D., Horn, T., Iqbal, S., Jensen, E., Kang, H., Keith, C. D., Kelleher, A., Keller, D., Khanal, H., Korover, I., Kumbartzki, G., Li, W., Lichtenstadt, J., Lindgren, R., Long, E., Malace, S., Markowitz, P., Maxwell, J., Meekins, D. M., Meziani, Z. E., McLean, C., Michaels, R., Mihovilovič, M., Muangma, N., Camacho, C. Munoz, Musson, J., Myers, K., Oh, Y., Carmignotto, M. Pannunzio, Perdrisat, C., Phillips, S., Piasetzky, E., Pierce, J., Punjabi, V., Qiang, Y., Reimer, P. E., Roblin, Y., Ron, G., Rondon, O., Russo, G., Saenboonruang, K., Sawatzky, B., Shahinyan, A., Shneor, R., Širca, S., Sjoegren, J., Solvignon-Slifer, P., Sparveris, N., Sulkosky, V., Wesselmann, F., Yan, W., Yang, H., Yao, H., Ye, Z., Yurov, M., Zhang, Y., Zhao, Y. X., and Zheng, X.

Abstract

The strong interaction is not well understood at low energies or for interactions with low momentum transfer. Chiral perturbation theory gives testable predictions for the nucleonic generalized polarizabilities, which are fundamental quantities describing the nucleon’s response to an external field. We report a measurement of the proton’s generalized spin polarizabilities extracted with a polarized electron beam and a polarized solid ammonia target in the region where chiral perturbation theory is expected to be valid. The investigated structure function g2characterizes the internal spin structure of the proton. From its moments, we extract the longitudinal–transverse spin polarizability δLTand twist-3 matrix element and polarizability d2¯. Our results provide discriminating power between existing chiral perturbation theory calculations and will help provide a better understanding of this strong quantum chromodynamics regime.

Published
2022
Full Text
View/download PDF

4. Measurement of the proton spin structure at long distances

Author

Zheng, X., Deur, A., Kang, H., Kuhn, S. E., Ripani, M., Zhang, J., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Atac, H., Avakian, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Boiarinov, S., Bondì, M., Bossù, F., Bosted, P., Briscoe, W. J., Brock, J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carlin, C., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Chen, J.-P., Choi, S., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Crede, V., D’Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Diehl, S., Djalali, C., Drozdov, V. A., Dupre, R., Ehrhart, M., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Forest, T. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F.-X., Glazier, D. I., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holmstrom, T., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keith, C. D., Keller, D., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., livingston, K., Long, E., MacGregor, I. J. D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meekins, D. G., Mineeva, T., Mirazita, M., Mokeev, V., Mullen, C., Nadel-Turonski, P., Neupane, K., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L., Park, K., Pasyuk, E., Phelps, W., Phillips, S. K., Pogorelko, O., Poudel, J., Prok, Y., Raue, B. A., Ritman, J., Rizzo, A., Rosner, G., Rossi, P., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Schumacher, R. A., Seely, M. L., Sharabian, Y. G., Shrestha, U., Širca, S., Slifer, K., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Sulkosky, V., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Yale, B., Zachariou, N., and Zhao, Z. W.

Abstract

Measuring the spin structure of protons and neutrons tests our understanding of how they arise from quarks and gluons, the fundamental building blocks of nuclear matter. At long distances, the coupling constant of the strong interaction becomes large, requiring non-perturbative methods to calculate quantum chromodynamics processes, such as lattice gauge theory or effective field theories. Here we report proton spin structure measurements from scattering a polarized electron beam off polarized protons. The spin-dependent cross-sections were measured at large distances, corresponding to the region of low momentum transfer squared between 0.012 and 1.0 GeV2. This kinematic range provides unique tests of chiral effective field theory predictions. Our results show that a complete description of the nucleon spin remains elusive, and call for further theoretical works, for example, in lattice quantum chromodynamics. Finally, our data extrapolated to the photon point agree with the Gerasimov–Drell–Hearn sum rule, a fundamental prediction of quantum field theory that relates the anomalous magnetic moment of the proton to its integrated spin-dependent cross-sections.

Published
2021
Full Text
View/download PDF

5. Deeply virtual Compton scattering off the neutron

Author

Benali, M., Desnault, C., Mazouz, M., Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J.-P., Defurne, M., de Jager, C. W., de Leo, R., Deur, A., El Fassi, L., Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Huber, G. M., Hyde, C. E., Iqbal, S., Itard, F., Kang, Ho., Kang, Hy., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Martí Jiménez-Argüello, A., Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Muangma, N., Muñoz Camacho, C., Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Pomatsalyuk, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatié, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zana, L., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.

Abstract

The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scattering. In this process, a high-energy electron is scattered off a nucleon by exchanging a virtual photon. Then, a highly energetic real photon is emitted from one of the quarks inside the nucleon, which carries information on the quark’s transverse position and longitudinal momentum. By measuring the cross-section of deeply virtual Compton scattering, Compton form factors related to the generalized parton distributions can be extracted. Here, we report the observation of unpolarized deeply virtual Compton scattering off a deuterium target. From the measured photon-electroproduction cross-sections, we have extracted the cross-section of a quasifree neutron and a coherent deuteron. Due to the approximate isospin symmetry of quantum chromodynamics, we can determine the contributions from the different quark flavours to the helicity-conserved Compton form factors by combining our measurements with previous ones probing the proton’s internal structure. These results advance our understanding of the description of the nucleon structure, which is important to solve the proton spin puzzle.

Published
2020
Full Text
View/download PDF

6. A small proton charge radius from an electron–proton scattering experiment

Author

Xiong, W., Gasparian, A., Gao, H., Dutta, D., Khandaker, M., Liyanage, N., Pasyuk, E., Peng, C., Bai, X., Ye, L., Gnanvo, K., Gu, C., Levillain, M., Yan, X., Higinbotham, D. W., Meziane, M., Ye, Z., Adhikari, K., Aljawrneh, B., Bhatt, H., Bhetuwal, D., Brock, J., Burkert, V., Carlin, C., Deur, A., Di, D., Dunne, J., Ekanayaka, P., El-Fassi, L., Emmich, B., Gan, L., Glamazdin, O., Kabir, M. L., Karki, A., Keith, C., Kowalski, S., Lagerquist, V., Larin, I., Liu, T., Liyanage, A., Maxwell, J., Meekins, D., Nazeer, S. J., Nelyubin, V., Nguyen, H., Pedroni, R., Perdrisat, C., Pierce, J., Punjabi, V., Shabestari, M., Shahinyan, A., Silwal, R., Stepanyan, S., Subedi, A., Tarasov, V. V., Ton, N., Zhang, Y., and Zhao, Z. W.

Abstract

Elastic electron–proton scattering (e–p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, rp. In 2010, a new method using muonic hydrogen atoms1found a substantial discrepancy compared with previous results2, which became known as the ‘proton radius puzzle’. Despite experimental and theoretical efforts, the puzzle remains unresolved. In fact, there is a discrepancy between the two most recent spectroscopic measurements conducted on ordinary hydrogen3,4. Here we report on the proton charge radius experiment at Jefferson Laboratory (PRad), a high-precision e–p experiment that was established after the discrepancy was identified. We used a magnetic-spectrometer-free method along with a windowless hydrogen gas target, which overcame several limitations of previous e–p experiments and enabled measurements at very small forward-scattering angles. Our result, rp= 0.831 ± 0.007stat± 0.012systfemtometres, is smaller than the most recent high-precision e–p measurement5and 2.7 standard deviations smaller than the average of all e–p experimental results6. The smaller rpwe have now measured supports the value found by two previous muonic hydrogen experiments1,7. In addition, our finding agrees with the revised value (announced in 2019) for the Rydberg constant8—one of the most accurately evaluated fundamental constants in physics.

Published
2019
Full Text
View/download PDF

7. Phenomenology of the deuteron electromagnetic form factors

Author

Abbott, D., Ahmidouch, A., Anklin, H., Arvieux, J., Ball, J., Beedoe, S., Beise, E.J., Bimbot, L., Boeglin, W., Breuer, H., Carlini, R., Chant, N.S., Danagoulian, S., Dow, K., Ducret, J.-E., Dunne, J., Ewell, L., Eyraud, L., Furget, C., Garçcon, M., Gilman, R., Glashausser, C., Gueye, P., Gustafsson, K., Hafidi, K., Honegger, A., Jourdan, J., Kox, S., Kumbartzki, G., Lu, L., Lung, A., Markowitz, P., McIntyre, J., Meekins, D., Merchez, F., Mitchell, J., Mohring, R., Mtingwa, S., Mrktchyan, H., Pitz, D., Qin, L., Ransome, R., Réal, J.-S., Roos, P.G., Rutt, P., Sawafta, R., Stepanyan, S., Tieulent, R., Tomasi-Gustafsson, E., Turchinetz, W., Vansyoc, K., Volmer, J., Voutier, E., Williamson, C., Wood, S.A., Yan, C., Zhao, J., and Zhao, W.

Abstract

Abstract:: A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering, at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer range 0-7 fm−1. This procedure is made possible with the advent of recent polarization measurements. The parameterizations allow a phenomenological characterization of the deuteron electromagnetic structure. They can be used to remove ambiguities in the form factors extraction from future polarization data.

Published
2000
Full Text
View/download PDF

8. Tensor polarization in elastic electron-deuteron scattering to the highest possible momentum transfers

Author

Garçon, M., Abbott, D., Ahmidouch, A., Anklin, H., Arvieux, J., Ball, J., Beedoe, S., Beise, E.J., Bimbot, L., Boeglin, W., Breuer, H., Carlini, R., Chant, N.S., Danagoulian, S., Dow, K., Ducret, J.-E., Dunne, J., Ewell, L., Eyraud, L., Furget, C., Gilman, R., Glashausser, C., Gueye, P., Gustafsson, K., Hafidi, K., Honegger, A., Jourdan, J., Kox, S., Kumbartzki, G., Lu, L., Lung, A., Mack, D., Markowitz, P., McIntyre, J., Meekins, D., Merchez, F., Mitchell, J., Mohring, R., Mtingwa, S., Mrktchyan, H., Pitz, D., Qin, L., Ransome, R., Réal, J.-S., Roos, P.G., Rutt, P., Schmidt, W., Sawafta, R., Stepanyan, S., Stephenson, E.J., Tieulent, R., Tomasi-Gustafsson, E., Turchinetz, W., Vansyoc, K., Volmer, J., Voutier, E., Vulcan, W., Williamson, C., Wood, S.A., Yan, C., Zhao, J., and Zhao, W.

Published
1999
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results