Abstract: We consider the coupling of the metric-affine bumblebee gravity model to scalar matter and calculate the lower -order contributions to two -point functions of bumblebee and scalar fields in the weak gravity approximation. We also obtain the one -loop effective potentials for both scalar and vector fields.

Abstract: A detailed beta -decay study of the low- and high -spin states in 216 Bi has been performed at the ISOLDE Decay Station at the CERN-ISOLDE facility. In total, 48 new levels and 83 new transitions in the beta -decay daughter 216 Po were identified. Shell -model calculations for excited states in 216 Bi and 216 Po were performed using the H208 and the modified Kuo-Herling particle effective interactions. Based on the experimental observations and the shell -model calculations, the most likely spin and parity assignments for the beta -decaying states in 216 Bi are (3 – ) and (8 – ), respectively.

Abstract: The excited structure of the single-hole nucleus 131 Sn populated by the beta – decay of 131 In was investigated in detail at the ISOLDE facility at CERN. This new experiment took advantage of isomeric purification capabilities provided by resonant ionization, making it possible to independently study the decay of each isomer for the first time. The position of the first-excited nu h 11 / 2 neutron-hole state was confirmed via an independent mass spectroscopy experiment performed at the Ion Guide Isotope Separator On-Line facility at the University of Jyv & auml;skyl & auml;. The level scheme of 131 Sn was notably expanded with the addition of 31 new gamma-ray transitions and 22 new excited levels. The gamma-emitting excited levels above the neutron separation energy in 131 Sn were investigated, revealing a large number of states, which in some cases decay by transitions to other neutron-unbound states. Our analysis showed the dependence between the population of these states in 131 Sn and the beta-decaying 131 In state feeding them. Profiting from the isomer selectivity, it was possible to estimate the direct beta feeding to the 3/2+ / 2 + ground and 11/2- / 2 – isomeric states, disentangling the contributions from the three indium parent states. This made possible to resolve the discrepancies in log ft for first-forbidden transitions observed in previous studies, and to determine the beta-delayed neutron decay probability (Pn) P n ) values of each indium isomers independently. The first measurement of subnanosecond lifetimes in 131 Sn was performed in this work. A short T 1 / 2 = 18(4)-ps value was measured for the 1/2+ / 2 + neutron single-hole 332-keV state, which indicates an enhanced l-forbidden M 1 behavior for the nu 3 s – 1 1/2 / 2 -> nu 3 d – 13 / 2 transition. The measured half-lives of high-energy states populated in the beta decay of the (21/2+) / 2 + ) second isomeric state ( 131 m 2 In) provided valuable information on transition rates, supporting the interpretation of these levels as core-excited states analogous to those observed in the doubly-magic 132 Sn.

Abstract: The branching fraction B(B-0 -> D*(-)tau(+)nu(tau)) is measured relative to that of the normalization mode B-0 -> D*(-) pi(+)pi(-)pi(+) using hadronic tau(+) -> pi(+)pi(-)pi(+) (pi(0))(nu) over bar (tau) decays in proton-proton collision data at a center-of-mass energy of 13 TeV collected by the LHCb experiment, corresponding to an integrated luminosity of 2 fb(-1). The measured ratio is B(B-0 -> D*(-)tau(+)nu(tau))/B(B-0 -> D*(-) pi(+)pi(-)pi(+)) = 1.70 +/- 0.10(-0.10)(+0.11), where the first uncertainty is statistical and the second is related to systematic effects. Using established branching fractions for the B-0 -> D*(-) pi(+)pi(-)pi(+) and B-0 -> D*(-)mu(+)nu(mu) modes, the lepton universality test R(D*(-)) = B(B-0 -> D*(-)tau(+)nu(tau))/B(B-0 -> D*(-)mu(+)nu(mu)) is calculated, R(D*(-)) = 0.247 +/- 0.015 +/- 0.015 +/- 0.012, where the third uncertainty is due to the uncertainties on the external branching fractions. This result is consistent with the Standard Model prediction and with previous measurements.

Abstract: Current cosmological tensions show that it is crucial to test the predictions from the canonical ACDM paradigm at different cosmic times. One very appealing test of structure formation in the Universe is the growth rate of structure in our universe f, usually parametrized via the growth index gamma, with f equivalent to Omega(m)(a)gamma and gamma similar or equal to 0.55 in the standard ACDM case. Recent studies have claimed a suppression of the growth of structure from a variety of cosmological observations, characterized by gamma > 0.55. By employing different self-consistent growth parametrizations schemes, we show here that gamma < 0.55, obtaining instead an enhanced growth of structure today. This preference reaches the 3 sigma significance using cosmic microwave background observations, supernova Ia and baryon acoustic oscillation measurements. The addition of cosmic microwave background lensing data relaxes such a preference to the 2 sigma level, since a larger lensing effect can always be compensated with a smaller structure growth, or, equivalently, with gamma > 0.55. We have also included the lensing amplitude AL as a free parameter in our data analysis, showing that the preference for AL > 1 still remains, except for some particular parametrizations when lensing observations are included. We also do not find any significant preference for an oscillatory dependence of AL, AL + Am sin l. To further reassess the effects of a nonstandard growth, we have computed by means of N-body simulations the dark matter density fields, the dark matter halo mass functions and the halo density profiles for different values of gamma. Future observations from the Square Kilometer Array, reducing by a factor of 3 the current errors on the gamma parameter, further confirm or refute with a strong statistical significance the deviation of the growth index from its standard value.