43 research outputs found

    Preheating in radiative corrections to ϕ4\phi^4 inflation with non-minimal coupling in Palatini formulation

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    We discuss the impact of the preheating stage in radiative corrections due to interaction of the inflaton to fermions to ϕ4\phi^4 inflation with non-minimal coupling in Palatini formulation. In Palatini inflation with large non-minimal coupling the field is allow to return to the plateau region during the reheating stage, so the average equation of state per oscillations is closer to 1-1 than to 1/31/3. The incursion in the plateau leads, however, to a highly efficient tachyonic instability able to reheat the Universe in less than one e-fold. By taking into account prescription II discussed in the literature, in the wide range of κξ\kappa-\xi, we figure out spectral index nsn_s and tensor-to-scalar ratio rr which are compatible with the data given by the Keck Array/BICEP2 and Planck collaborations.Comment: 11 pages, 1 figur

    Beam Test Results of the RADiCAL -- a Radiation Hard Innovative EM Calorimeter

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    High performance calorimetry conducted at future hadron colliders, such as the FCC-hh, poses a significant challenge for applying current detector technologies due to unprecedented beam luminosities and radiation fields. Solutions include developing scintillators that are capable of separating events at the sub-fifty picosecond level while also maintaining performance after extreme and constant neutron and ionizing radiation exposure. The RADiCAL is an approach that incorporates radiation tolerant materials in a sampling 'shashlik' style calorimeter configuration, using quartz capillaries filled with organic liquid or polymer-based wavelength shifters embedded in layers of tungsten plates and LYSO crystals. This novel design intends to address the Priority Research Directions (PRD) for calorimetry listed in the DOE Basic Research Needs (BRN) workshop for HEP Instrumentation. Here we report preliminary results from an experimental run at the Fermilab Test Beam Facility in June 2022. These tests demonstrate that the RADiCAL concept is capable of < 50 ps timing resolution.Comment: 5 pages, 10 figures, SCINT22 conferenc

    Scintillation timing characteristics of common plastics for radiation detection excited with 120 GeV protons

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    The timing characteristics of scintillators must be understood in order to determine which applications they are appropriate for. Polyethylene naphthalate (PEN) and polyethylene teraphthalate (PET) are common plastics with uncommon scintillation properties. Here, we report the timing characteristics of PEN and PET, determined by exciting them with 120 GeV protons. The test beam was provided by Fermi National Accelerator Laboratory, and the scintillators were tested at the Fermilab Test Beam Facility. PEN and PET are found to have dominant decay constants of 34.91 ns and 6.78 ns, respectively