Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

ICARUS at the Fermilab Short-Baseline Neutrino program: initial operation

The ICARUS collaboration employed the 760-ton T600 detector in a successful 3-year physics run at the underground LNGS laboratory, performing a sensitive search for LSND-like anomalous ν e appearance in the CERN Neutrino to Gran Sasso beam, which contributed to the constraints on the allowed neutrino oscillation parameters to a narrow region around 1 eV2 . After a significant overhaul at CERN, the T600 detector has been installed at Fermilab. In 2020 the cryogenic commissioning began with detector cool down, liquid argon filling and recirculation. ICARUS then started its operations collecting the first neutrino events from the booster neutrino beam (BNB) and the Neutrinos at the Main Injector (NuMI) beam off-axis, which were used to test the ICARUS event selection, reconstruction and analysis algorithms. ICARUS successfully completed its commissioning phase in June 2022. The first goal of the ICARUS data taking will be a study to either confirm or refute the claim by Neutrino-4 short-baseline reactor experiment. ICARUS will also perform measurement of neutrino cross sections with the NuMI beam and several Beyond Standard Model searches. After the first year of operations, ICARUS will search for evidence of sterile neutrinos jointly with the Short-Baseline Near Detector, within the Short-Baseline Neutrino program. In this paper, the main activities carried out during the overhauling and installation phases are highlighted. Preliminary technical results from the ICARUS commissioning data with the BNB and NuMI beams are presented both in terms of performance of all ICARUS subsystems and of capability to select and reconstruct neutrino events.

Study of the 4He(4He,4He)4He* inelastic scattering at the MAGNEX facility

The 4He(4He,4He)4He* inelastic scattering was revisited in a new coincidence measurement at the MAGNEX facility of Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud. The 4He + 4He → 4He + 4He* → 4He + 3H + 1H and 4He + 4He → 4He + 4He* → 4He + 3He + n reactions were measured simultaneously by detecting the 4He particles at the MAGNEX magnetic spectrometer in coincidence with the 3H and 3He at the OSCAR silicon telescope. The main concept of the experiment is described and the data reduction strategy is reported.

Penetrance of hypertrophic cardiomyopathy and outcome in sarcomeric mutation carriers

Background

Predictive genetic screening of the first degree relatives of patients with hypertrophic cardiomyopathy (HCM) caused by sarcomere protein (SP) gene mutations is current standard of care, but there are few data on long-term outcomes in mutation carriers without HCM.

Purpose

To establish the role of sex and genotype in HCM penetrance as well as the rate of major adverse clinical events in SP mutation carriers and following the diagnosis of HCM.

Methods

Retrospective analysis of consecutive adult and paediatric SP mutation carriers identified during family screening and who did not fulfill diagnostic criteria for HCM at first evaluation.

Results

321 individuals from 170 families [median age first evaluation 15.2 years (IQR 7.3–32.6); 153 (47.7%) males] were evaluated. Causal SP genes were: MYBPC3 (n=133 (41.4%)), MYH7 (n=77 (24.0%)), TNNI3 (n=51 (15.9%)), TNNT2 (n=40 (12.5%)), TPM1 (n=9 (2.8%)), MYL2 (n=6 (1.9%)), and ACTC1 (n=1 (0.3%)); 4 (1.3%) carried multiple mutations.

After a median follow up of 7.4 years (IQR 2.5–12.7), 89 (27.7%) patients developed HCM. Disease penetrance at the age of 50 years was 47% (95% CI 38%-56%). One hundred and fifty three (47.7%) individuals underwent cardiac magnetic resonance (CMR) imaging; among those diagnosed with HCM, 22/89 (24.7%) fulfilled criteria on CMR but not echocardiography.

In a multivariable model adjusted for genotype, follow up duration and evaluation with CMR, independent predictors of HCM development were male sex (HR 3.11; CI 1.82–5.32) and abnormal ECG (HR 7.87; CI 4.43–13.97). Patients with MYH7 and multiple mutations were more likely to develop HCM than those with MYBPC3 mutations (HR 2.03; CI 1.04–3.96 and HR 10.13; CI 1.40–72.92, respectively). Disease penetrance was lowest in carriers of TNNI3 mutations (HR 0.13; CI 0.03–0.48).

There were no major adverse events in individuals without HCM. Following the diagnosis of HCM, the combined rate of all-cause death, appropriate defibrillator shock or resuscitated cardiac arrest was 1.1%/year [median follow up 4.0 years (IQR 2.1–8.9)].

Conclusions

Approximately 50% of SP mutation carriers develop HCM by the age of 50 and become prone to disease complications during long-term follow-up. Sex, MYH7 mutations and the presence of an abnormal ECG are associated with a higher risk of disease development. CMR should be employed systematically in long-term screening.

HCM penetrance by sex

Funding Acknowledgement

Type of funding source: None

Study of High-Energy Fission in Inverse Kinematics

Fission at low excitation energy, is a process in which both macroscopic and microscopic aspects are involved. Some features in the total kinetic energy and in the N/Z distributions of the fragments, commonly associated with shell effects, came out in a series of recent experiments with high excitation energy fusionfission reactions in inverse kinematics. In the latest experiment of this campaign, a study of high-energy fission and quasi-fission between a 238U beam and a series of light targets was carried out by using the aforementioned technique, in order to probe the role of the shell structure in these processes.