Observation of the GZK Cutoff Using the HiRes Detector

The High Resolution Fly's Eye (HiRes) experiment has observed the GZK cutoff. HiRes observes two features in the ultra-high energy cosmic ray (UHECR) flux spectrum: the Ankle at an energy of $4\times10^{18}$ eV and a high energy suppression at $6\times10^{19}$ eV. The later feature is at exactly the right energy for the GZK cutoff according to the $E_{1/2}$ criterion. HiRes cannot claim to observe a third feature at lower energies, the Second Knee. The HiRes monocular spectra are presented, along with data demonstrating our control and understanding of systematic uncertainties affecting the energy and flux measurements.Comment: 8 pages, 12 figures. Proceedings submission for CRIS 2006, Catania, May/June 200

Stellar evolution and modelling stars

In this chapter I give an overall description of the structure and evolution of stars of different masses, and review the main ingredients included in state-of-the-art calculations aiming at reproducing observational features. I give particular emphasis to processes where large uncertainties still exist as they have strong impact on stellar properties derived from large compilations of tracks and isochrones, and are therefore of fundamental importance in many fields of astrophysics.Comment: Lecture presented at the IVth Azores International Advanced School in Space Sciences on "Asteroseismology and Exoplanets: Listening to the Stars and Searching for New Worlds" (arXiv:1709.00645), which took place in Horta, Azores Islands, Portugal in July 201

Performance Measurements of Optical Scintillating Fibers After Repeated Exposure to Radiation

2020 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2020 -- 31 October 2020 through 7 November 2020 -- -- 176716We report the preliminary results from repeated irradiations of optical scintillating fibers exposed to gamma radiation. Optical fibers degrade in radiation fields, but exhibit some recovery once removed. Study of repeated irradiations are difficult to find in the literature. We find that a UV-blue optical wavelength shifting fiber exhibits permanent degradation, the recovery is incomplete, and an interesting two step damage process that appears to affect which wavelengths are darkened at different rates. © 2020 IEEENational Institutes of Health, NIH: P30 CA086862; FermilabACKNOWLEDGMENT We acknowledge the staff at the University of Iowa College of Medicine and Holden Comprehensive Cancer Center Radiation and Free Radical Research (RFRR) Core for radiation services. The RFRR core facility is supported by funding from NIH P30 CA086862. We also thank Jim Freeman at Fermi National Accelerator Laboratory for providing the scintillating fibers.We acknowledge the staff at the University of Iowa College of Medicine and Holden Comprehensive Cancer Center Radiation and Free Radical Research (RFRR) Core for radiation services. The RFRR core facility is supported by funding from NIH P30 CA086862. We also thank Jim Freeman at Fermi National Accelerator Laboratory for providing the scintillating fibers

Results from in Situ Monitoring of Radiation Damage of Scintillation Fibers

2020 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2020 -- 31 October 2020 through 7 November 2020 -- -- 176716We report preliminary results from in situ monitoring of an optical scintillating fiber while being exposed to a cesium-173 gamma radiatior. We measured the degradation of fiber transmittance across the visible spectrum as a function of time. We observed that the region below 500 nm was degraded quickly and thoroughly while wavelengths above 500 nm lost clarity more slowly. © 2020 IEEENational Institutes of Health, NIH: P30 CA086862; FermilabACKNOWLEDGMENT We acknowledge the staff at the University of Iowa College of Medicine and Holden Comprehensive Cancer Center Radiation and Free Radical Research (RFRR) Core for radiation services. The RFRR core facility is supported by funding from NIH P30 CA086862. We also thank Jim Freeman at Fermi National Accelerator Laboratory for providing the scintillating fibers.We acknowledge the staff at the University of Iowa College of Medicine and Holden Comprehensive Cancer Center Radiation and Free Radical Research (RFRR) Core for radiation services. The RFRR core facility is supported by funding from NIH P30 CA086862. We also thank Jim Freeman at Fermi National Accelerator Laboratory for providing the scintillating fibers

Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV

Peer reviewe

Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search

Peer reviewe

Search for heavy resonances decaying into a vector boson and a Higgs boson in final states with charged leptons, neutrinos, and b quarks

Peer reviewe

Measurement of CP observables in B± → D(⁎)K± and B± → D(⁎)π± decays

Measurements of CP observables in B ± →D (⁎) K ± and B ± →D (⁎) π ± decays are presented, where D (⁎) indicates a neutral D or D ⁎ meson that is an admixture of D (⁎)0 and D¯ (⁎)0 states. Decays of the D ⁎ meson to the Dπ 0 and Dγ final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the B candidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K ± π ∓ , K + K − and π + π − final states. The analysis uses a sample of charged B mesons produced in pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0 fb −1 taken at centre-of-mass energies of s=7, 8 and 13 TeV, respectively. The study of B ± →D ⁎ K ± and B ± →D ⁎ π ± decays using a partial reconstruction method is the first of its kind, while the measurement of B ± →DK ± and B ± →Dπ ± decays is an update of previous LHCb measurements. The B ± →DK ± results are the most precise to date

Measurement of the mass difference between top quark and antiquark in pp collisions at root s=8 TeV

Peer reviewe

Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

Peer reviewe