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

We discuss the impact of the preheating stage in radiative corrections due to interaction of the inflaton to fermions to $\phi^4$ 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 $-1$ than to $1/3$. 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 $\kappa-\xi$, we figure out spectral index $n_s$ and tensor-to-scalar ratio $r$ which are compatible with the data given by the Keck Array/BICEP2 and Planck collaborations.Comment: 11 pages, 1 figur

Inflationary predictions of double-well, Coleman-Weinberg, and hilltop potentials with non-minimal coupling

We discuss how the non-minimal coupling $\xi\phi^2R$ between the inflaton and the Ricci scalar affects the predictions of single field inflation models where the inflaton has a non-zero vacuum expectation value (VEV) $v$ after inflation. We show that, for inflaton values both above the VEV and below the VEV during inflation, under certain conditions the inflationary predictions become approximately the same as the predictions of the Starobinsky model. We then analyze inflation with double-well and Coleman-Weinberg potentials in detail, displaying the regions in the $v$-$\xi$ plane for which the spectral index $n_s$ and the tensor-to-scalar ratio $r$ values are compatible with the current observations. $r$ is always larger than 0.002 in these regions. Finally, we consider the effect of $\xi$ on small field inflation (hilltop) potentials.Comment: 1+21 pages, 9 figures. v2: added references and a few clarifications, matches published versio

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

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

Tau Neutrinos in the Next Decade: From GeV to EeV

Tau neutrinos are the least studied particle in the standard model. This whitepaper discusses the current and expected upcoming status of tau neutrino physics with attention to the broad experimental and theoretical landscape spanning long-baseline, beam-dump, collider, and astrophysical experiments. This whitepaper was prepared as a part of the NuTau2021 Workshop

Non-minimally coupled Natural Inflation: Palatini and Metric formalism with the recent BICEP/Keck

Abstract In this work, we show the effect of the non-minimal coupling ξϕ 2 R on the inflationary parameters by considering the single-field inflation and present the inflationary predictions of the appealing potential for the particle physics viewpoint: Natural Inflation, an axion-like inflaton which has a cosine-type periodic potential and the inflaton naturally emerges as a pseudo-Nambu-Goldstone boson with a spontaneously broken global symmetry. We present the inflationary predictions for this potential, ns , r, and α = dns /d ln  k. In addition, we assume standard thermal history after inflation, and using this, for considered potential, we show compatible regions for the ns , r within the recent BICEP/Keck results.</jats:p

Palatini double-well and Coleman-Weinberg potentials with non-minimal coupling

Abstract We present the impact of non-minimal coupling ξϕ2 R on the inflationary parameters by taking into account the models of single-field inflation with the inflaton that has a non-zero vacuum expectation value (v) after the period of inflation in Palatini gravity. We discuss the well-known symmetry-breaking type potentials, namely the double-well potential and Coleman-Weinberg potential. We show that the inflationary predictions, n s and r, of these potentials for both ϕ &gt; v and ϕ &lt; v inflation are compatible with the recent measurements within the regions of the v-ξ plane. Finally, we take into account the inflationary predictions of Coleman-Weinberg potential for selected ξ values as a function of v in the Palatini formalism.</jats:p