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Author Chen, Y.H.; Yao, D.L.; Zheng, H.Q.
Title (up) A Study of rho-omega Mixing in Resonance Chiral Theory Type Journal Article
Year 2018 Publication Communications in Theoretical Physics Abbreviated Journal Commun. Theor. Phys.
Volume 69 Issue 1 Pages 50-58
Keywords Chiral Lagrangians; vector mesons; 1/N-C expansion
Abstract The strong and electromagnetic corrections to rho-omega mixing are calculated using an SU(2) version of resonance chiral theory up to next-to-leading orders in 1/N-C expansion, respectively. Up to our accuracy, the effect of the momentum dependence of rho-omega mixing is incorporated due to the inclusion of loop contributions. We analyze the impact of rho-omega mixing on the pion vector form factor by performing numerical fit to the data extracted from e(+)e(-) -> pi(+)pi(-) and tau -> nu(tau)2 pi, while the decay width of omega -> pi(+)pi(-) is taken into account as a constraint. It is found that the momentum dependence is significant in a good description of the experimental data. In addition, based on the fitted values of the involved parameters, we analyze the decay width of omega -> pi(+)pi(-), which turns out to be highly dominated by the rho-omega mixing effect.
Address [Chen, Yun-Hua] Univ Sci & Technol Beijing, Sch Math & Phys, Beijing 100083, Peoples R China, Email: yhchen@ustb.edu.cn;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0253-6102 ISBN Medium
Area Expedition Conference
Notes WOS:000422832600010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3453
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Author Valdes-Cortez, C.; Mansour, I.; Rivard, M.J.; Ballester, F.; Mainegra-Hing, E.; Thomson, R.M.; Vijande, J.
Title (up) A study of Type B uncertainties associated with the photoelectric effect in low-energy Monte Carlo simulations Type Journal Article
Year 2021 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.
Volume 66 Issue 10 Pages 105014 - 14pp
Keywords Monte Carlo simulations; brachytherapy; low energy physics; photoelectric effect
Abstract Purpose. To estimate Type B uncertainties in absorbed-dose calculations arising from the different implementations in current state-of-the-art Monte Carlo (MC) codes of low-energy photon cross-sections (<200 keV). Methods. MC simulations are carried out using three codes widely used in the low-energy domain: PENELOPE-2018, EGSnrc, and MCNP. Three dosimetry-relevant quantities are considered: mass energy-absorption coefficients for water, air, graphite, and their respective ratios; absorbed dose; and photon-fluence spectra. The absorbed dose and the photon-fluence spectra are scored in a spherical water phantom of 15 cm radius. Benchmark simulations using similar cross-sections have been performed. The differences observed between these quantities when different cross-sections are considered are taken to be a good estimator for the corresponding Type B uncertainties. Results. A conservative Type B uncertainty for the absorbed dose (k = 2) of 1.2%-1.7% (<50 keV), 0.6%-1.2% (50-100 keV), and 0.3% (100-200 keV) is estimated. The photon-fluence spectrum does not present clinically relevant differences that merit considering additional Type B uncertainties except for energies below 25 keV, where a Type B uncertainty of 0.5% is obtained. Below 30 keV, mass energy-absorption coefficients show Type B uncertainties (k = 2) of about 1.5% (water and air), and 2% (graphite), diminishing in all materials for larger energies and reaching values about 1% (40-50 keV) and 0.5% (50-75 keV). With respect to their ratios, the only significant Type B uncertainties are observed in the case of the water-to-graphite ratio for energies below 30 keV, being about 0.7% (k = 2). Conclusions. In contrast with the intermediate (about 500 keV) or high (about 1 MeV) energy domains, Type B uncertainties due to the different cross-sections implementation cannot be considered subdominant with respect to Type A uncertainties or even to other sources of Type B uncertainties (tally volume averaging, manufacturing tolerances, etc). Therefore, the values reported here should be accommodated within the uncertainty budget in low-energy photon dosimetry studies.
Address [Valdes-Cortez, Christian; Ballester, Facundo; Vijande, Javier] Univ Valencia UV, Dept Fis Atom Mol & Nucl, Burjassot, Spain, Email: javier.vijande@uv.es
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9155 ISBN Medium
Area Expedition Conference
Notes WOS:000655291500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4847
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Author Hinarejos, M.; Bañuls, M.C.; Perez, A.
Title (up) A Study of Wigner Functions for Discrete-Time Quantum Walks Type Journal Article
Year 2013 Publication Journal of Computational and Theoretical Nanoscience Abbreviated Journal J. Comput. Theor. Nanosci.
Volume 10 Issue 7 Pages 1626-1633
Keywords Quantum Walk; Wigner Function; Negativity
Abstract We perform a systematic study of the discrete time Quantum Walk on one dimension using Wigner functions, which are generalized to include the chirality (or coin) degree of freedom. In particular, we analyze the evolution of the negative volume in phase space, as a function of time, for different initial states. This negativity can be used to quantify the degree of departure of the system from a classical state. We also relate this quantity to the entanglement between the coin and walker subspaces.
Address [Hinarejos, M.; Perez, A.] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain
Corporate Author Thesis
Publisher Amer Scientific Publishers Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1546-1955 ISBN Medium
Area Expedition Conference
Notes WOS:000322605800014 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1529
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Author HAWC Collaboration (Albert, A. et al); Salesa Greus, F.
Title (up) A Survey of Active Galaxies at TeV Photon Energies with the HAWC Gamma-Ray Observatory Type Journal Article
Year 2021 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume 907 Issue 2 Pages 67 - 18pp
Keywords Active galactic nuclei; Blazars; Gamma-rays; Gamma-ray sources; Sky surveys; Radio galaxies
Abstract The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory continuously detects TeV photons and particles within its large field of view, accumulating every day a deeper exposure of two-thirds of the sky. We analyzed 1523 days of HAWC live data acquired over four and a half years, in a follow-up analysis of 138 nearby (z < 0.3) active galactic nuclei from the Third Catalog of Hard Fermi-LAT sources culminating within 40 degrees of the zenith at Sierra Negra, the HAWC site. This search for persistent TeV emission used a maximum-likelihood analysis assuming intrinsic power-law spectra attenuated by pair production of gamma-ray photons with the extragalactic background light. HAWC clearly detects persistent emission from Mkn 421 and Mkn 501, the two brightest blazars in the TeV sky, at 65 sigma and 17 sigma level, respectively. Marginal evidence, just above the 3 sigma level, was found for three other known very high-energy emitters: the radio galaxy M87 and the BL Lac objects VER J0521+211 and 1ES 1215+303, the latter two at z similar to 0.1. We find a 4.2 sigma evidence for collective emission from the set of 30 previously reported very high-energy sources, with Mkn 421 and Mkn 501 excluded. Upper limits are presented for the sample under the power-law assumption and in the predefined (0.5-2.0), (2.0-8.0), and (8.0-32.0) TeV energy intervals.
Address [Albert, A.; Dingus, B. L.; Durocher, M.; Harding, J. P.; Kunde, G. J.; Malone, K.] Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA, Email: alberto@inaoep.mx;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-637x ISBN Medium
Area Expedition Conference
Notes WOS:000612927500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4712
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Author Hooper, D.; Leane, R.K.; Tsai, Y.D.; Wegsman, S.; Witte, S.J.
Title (up) A systematic study of hidden sector dark matter: application to the gamma-ray and antiproton excesses Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 163 - 38pp
Keywords Beyond Standard Model; Cosmology of Theories beyond the SM
Abstract In hidden sector models, dark matter does not directly couple to the particle content of the Standard Model, strongly suppressing rates at direct detection experiments, while still allowing for large signals from annihilation. In this paper, we conduct an extensive study of hidden sector dark matter, covering a wide range of dark matter spins, mediator spins, interaction diagrams, and annihilation final states, in each case determining whether the annihilations are s-wave (thus enabling efficient annihilation in the universe today). We then go on to consider a variety of portal interactions that allow the hidden sector annihilation products to decay into the Standard Model. We broadly classify constraints from relic density requirements and dwarf spheroidal galaxy observations. In the scenario that the hidden sector was in equilibrium with the Standard Model in the early universe, we place a lower bound on the portal coupling, as well as on the dark matter's elastic scattering cross section with nuclei. We apply our hidden sector results to the observed Galactic Center gamma-ray excess and the cosmic-ray antiproton excess. We find that both of these excesses can be simultaneously explained by a variety of hidden sector models, without any tension with constraints from observations of dwarf spheroidal galaxies.
Address [Hooper, Dan; Tsai, Yu-Dai] Fermilab Natl Accelerator Lab, Fermilab, Batavia, IL 60510 USA, Email: dhooper@fnal.gov;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000555828300002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4491
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