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Physics

Physics Faculty Publications

Astrophysics and Astronomy

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Full-Text Articles in Physical Sciences and Mathematics

Perturbative Unitarity And Nec Violation In Genesis Cosmology, Yong Cai, Ji Xu, Shuai Zhao, Siyi Zhou Jan 2022

Perturbative Unitarity And Nec Violation In Genesis Cosmology, Yong Cai, Ji Xu, Shuai Zhao, Siyi Zhou

Physics Faculty Publications

Explorations of the violation of null energy condition (NEC) in cosmology could enrich our understanding of the very early universe and the related gravity theories. Although a fully stable NEC violation can be realized in the “beyond Horndeski” theory, it remains an open question whether a violation of the NEC is allowed by some fundamental properties of UV-complete theories or the consistency requirements of effective field theory (EFT). We investigate the tree-level perturbative unitarity for stable NEC violations in the contexts of both Galileon and “beyond Horndeski” genesis cosmology, in which the universe is asymptotically Minkowskian in the past. We …


Measurement Of Nuclear Transparency Ratios For Protons And Neutrons, M. Duer, O. Hen, E. Piasetzky, L. B. Weinstein, A. Schmidt, I. Korover, E. O. Cohen, H. Hakobyan, S. Adhikari, G. Angelini, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, A. Beck, I. Bedlinski, A. S. Biselli, S. Boiarinov, W. J. Briscoe, X. Zheng, Et Al., The Clas Collaboration Jan 2019

Measurement Of Nuclear Transparency Ratios For Protons And Neutrons, M. Duer, O. Hen, E. Piasetzky, L. B. Weinstein, A. Schmidt, I. Korover, E. O. Cohen, H. Hakobyan, S. Adhikari, G. Angelini, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, A. Beck, I. Bedlinski, A. S. Biselli, S. Boiarinov, W. J. Briscoe, X. Zheng, Et Al., The Clas Collaboration

Physics Faculty Publications

This paper presents, for the first time, measurements of neutron transparency ratios for nuclei relative to C measured using the (e, e'n) reaction, spanning measured neutron momenta of 1.4 to 2.4 GeV/c. The transparency ratios were extracted in two kinematical regions, corresponding to knockout of mean-field nucleons and to the breakup of Short-Range Correlated nucleon pairs. The extracted neutron transparency ratios are consistent with each other for the two measured kinematical regions and agree with the proton transparencies extracted from new and previous (e, e'p) measurements, including those from neutron-rich nuclei such as lead. The data also agree with and …


Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato Jan 2019

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

Physics Faculty Publications

Motivated by recently observed tension between O(α2s) calculations of very large transverse momentum dependence in both semi-inclusive deep inelastic scattering and Drell-Yan scattering, we repeat the details of the calculation through an O(α2s) transversely differential cross section. The results confirm earlier calculations, and provide further support to the observation that tension exists with current parton distribution and fragmentation functions.