| Records |
Author  |
Ellis, J.; Konoplich, R.; Mavromatos, N.E.; Nguyen, L.; Sakharov, A.S.; Sarkisyan-Grinbaum, E.K. |
| Title |
Robust constraint on Lorentz violation using Fermi-LAT gamma-ray burst data |
Type |
Journal Article |
| Year |
2019 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
99 |
Issue |
8 |
Pages |
083009 - 22pp |
| Keywords |
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| Abstract |
Models of quantum gravity suggest that the vacuum should be regarded as a medium with quantum structure that may have nontrivial effects on photon propagation, including the violation of Lorentz invariance. Fermi Large Area Telescope (LAT) observations of gamma-ray bursts (GRBs) are sensitive probes of Lorentz invariance, via studies of energy-dependent timing shifts in their rapidly varying photon emissions. We analyze the Fermi-LAT measurements of high-energy gamma rays from GRBs with known redshifts, allowing for the possibility of energy-dependent variations in emission times at the sources as well as a possible nontrivial refractive index in vacuo for photons. We use statistical estimators based on the irregularity, kurtosis, and skewness of bursts that are relatively bright in the 100 MeV to multi-GeV energy band to constrain possible dispersion effects during propagation. We find that the energy scale characterizing a linear energy dependence of the refractive index should exceed a few x10(17) GeV, and we estimate the sensitivity attainable with additional future sources to be detected by Fermi-LAT. |
| Address |
[Ellis, John; Mavromatos, Nikolaos E.] Kings Coll London, Dept Phys, Theoret Particle Phys & Cosmol Grp, London WC2R 2LS, England |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2470-0010 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000464745800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3982 |
| Permanent link to this record |
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| Author |
Durieux, G.; Irles, A.; Miralles, V.; Peñuelas, A.; Perello, M.; Poschl, R.; Vos, M. |
| Title |
The electro-weak couplings of the top and bottom quarks – Global fit and future prospects |
Type |
Journal Article |
| Year |
2019 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
12 |
Issue |
12 |
Pages |
098 - 44pp |
| Keywords |
Phenomenology of Field Theories in Higher Dimensions |
| Abstract |
We evaluate the implications of LHC and LEP/SLC measurements for the electro-weak couplings of the top and bottom quarks. We derive global bounds on the Wilson coefficients of ten two-fermion operators in an effective field theory description. The combination of hadron collider data with Z -pole measurements is found to yield tight limits on the operator coefficients that modify the left-handed couplings of the bottom and top quark to the Z boson. We also present projections for the high-luminosity phase of the LHC and for future electron-positron colliders. The bounds on the operator coefficients are expected to improve substantially during the remaining LHC programme, by factors of 1 to 5 if systematic uncertainties are scaled as statistical ones. The operation of an e(+)e(-) collider at a center-of-mass energy above the top-quark pair production threshold is expected to further improve the bounds by one to two orders of magnitude. The combination of measurements in pp and e(+)e(-) collisions allows for a percent-level determination of the top-quark Yukawa coupling, that is robust in a global fit. |
| Address |
[Durieux, Gauthier] Technion Israel Inst Technol, Dept Phys, IL-3200003 Haifa, Israel, Email: durieux@campus.technion.ac.il; |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000513489700002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4280 |
| Permanent link to this record |
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| Author |
Dudouet, J. et al; Gadea, A.; Perez-Vidal, R.M. |
| Title |
Excitations of the magic N=50 neutron-core revealed in Ga-81 |
Type |
Journal Article |
| Year |
2019 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
| Volume |
100 |
Issue |
1 |
Pages |
011301 - 6pp |
| Keywords |
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| Abstract |
The high-spin states of the neutron-rich Ga-81, with three valence protons outside a Ni-78 core, were measured. The measurement involved prompt gamma-ray spectroscopy of fission fragments isotopically identified using the combination of the variable mode spectrometer (VAMOS++) and the advanced gamma tracking array (AGATA). The new gamma-ray transitions, observed in coincidence with Ga-81 ions, and the corresponding level scheme do not confirm the high-spin levels reported earlier. The newly observed high-spin states in Ga-81 are interpreted using the results of state-of-the-art large-scale shell model (LSSM) calculations. The lower excitation energy levels are understood as resulting from the recoupling of three valence protons to the closed doubly magic core, while the highest excitation energy levels correspond to excitations of the magic N = 50 neutron core. These results support the doubly magic character of Ni-78 and the persistence of the N = 50 shell closure but also highlight the presence of strong proton-neutron correlations associated with the promotion of neutrons across the magic N = 50 shell gap, only few nucleons away from Ni-78. |
| Address |
[Dudouet, J.; Maquart, G.; Stezowski, O.; Ducoin, C.; Guinet, D.; Redon, N.] Univ Lyon 1, CNRS IN2P3, IPN Lyon, F-69622 Villeurbanne, France, Email: jeremie.dudouet@csnsm.in2p3.fr |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2469-9985 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000475500200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4095 |
| Permanent link to this record |
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| Author |
Driencourt-Mangin, F.; Rodrigo, G.; Sborlini, G.F.R.; Torres Bobadilla, W.J. |
| Title |
Universal four-dimensional representation of H -> gamma gamma at two loops through the Loop-Tree Duality |
Type |
Journal Article |
| Year |
2019 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
02 |
Issue |
2 |
Pages |
143 - 39pp |
| Keywords |
Scattering Amplitudes; Higgs Physics; Perturbative QCD |
| Abstract |
We extend useful properties of the H unintegrated dual amplitudes from one- to two-loop level, using the Loop-Tree Duality formalism. In particular, we show that the universality of the functional form regardless of the nature of the internal particle still holds at this order. We also present an algorithmic way to renormalise two-loop amplitudes, by locally cancelling the ultraviolet singularities at integrand level, thus allowing a full four-dimensional numerical implementation of the method. Our results are compared with analytic expressions already available in the literature, finding a perfect numerical agreement. The success of this computation plays a crucial role for the development of a fully local four-dimensional framework to compute physical observables at Next-to-Next-to Leading order and beyond. |
| Address |
[Driencourt-Mangin, Felix; Rodrigo, German; Sborlini, German F. R.; Bobadilla, William J. Torres] Univ Valencia, CSIC, IFIC, Apt Correus 22085, E-46071 Valencia, Spain, Email: felix.dm@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000459485300005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3922 |
| Permanent link to this record |
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| Author |
Donini, A.; Palomares-Ruiz, S.; Salvado, J. |
| Title |
Neutrino tomography of Earth |
Type |
Journal Article |
| Year |
2019 |
Publication |
Nature Physics |
Abbreviated Journal |
Nat. Phys. |
| Volume |
15 |
Issue |
1 |
Pages |
37-40 |
| Keywords |
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| Abstract |
Cosmic-ray interactions with the atmosphere produce a flux of neutrinos in all directions with energies extending above the TeV scale(1). The Earth is not a fully transparent medium for neutrinos with energies above a few TeV, as the neutrinonucleon cross-section is large enough to make the absorption probability non-negligible(2). Since absorption depends on energy and distance travelled, studying the distribution of the TeV atmospheric neutrinos passing through the Earth offers an opportunity to infer its density profiles(3-7). This has never been done, however, due to the lack of relevant data. Here we perform a neutrino-based tomography of the Earth using actual data-one-year of through-going muon atmospheric neutrino data collected by the IceCube telescope(8). Using only weak interactions, in a way that is completely independent of gravitational measurements, we are able to determine the mass of the Earth and its core, its moment of inertia, and to establish that the core is denser than the mantle. Our results demonstrate the feasibility of this approach to study the Earth's internal structure, which is complementary to traditional geophysics methods. Neutrino tomography could become more competitive as soon as more statistics is available, provided that the sources of systematic uncertainties are fully under control. |
| Address |
[Donini, Andrea; Palomares-Ruiz, Sergio; Salvado, Jordi] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Valencia, Spain, Email: sergiopr@ific.uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
Nature Publishing Group |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1745-2473 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000454733100017 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
3863 |
| Permanent link to this record |
