We present a measurement of the strong-phase difference between $D^0$ and ${\overline{D}}^0\to K_{\mathrm{S},\mathrm{L}}^0{K}^{+}{K}^{-}$ decays, performed through a study of quantum-entangled pairs of charm mesons. The measurement exploits a data sample equivalent to an integrated luminosity of $2.93{\mathrm{fb}}^{-1}$, collected by the BESIII detector in $e^{+}{e}^{-}$ collisions corresponding to the mass of the $\psi (3770)$ resonance. The strong-phase difference is an essential input to the determination of the Cabibbo-Kobayashi-Maskawa (CKM) angle $\gamma /{\varphi }_3$ through the decay $B^{-}\to D{K}^{-}$, where $D$ can be either a $D^0$ or a ${\overline{D}}^0$ decaying to $K_{\mathrm{S},\mathrm{L}}^0{K}^{+}{K}^{-}$. This is the most precise measurement to date of the strong-phase difference in these decays.

A search has been performed for neutrinos from two sources, the hep reaction in the solar $pp$ fusion chain and the ${\nu }_e$ component of the diffuse supernova neutrino background (DSNB), using the full dataset of the Sudbury Neutrino Observatory with a total exposure of $2.47\mathrm{kton}\text{−}\mathrm{years}$ after fiducialization. The hep search is performed using both a single-bin counting analysis and a likelihood fit. We find a best-fit flux that is compatible with solar model predictions while remaining consistent with zero flux, and set a one-sided upper limit of ${\mathrm{\Phi }}_{hep}<30\times {10}^3{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$ [90% credible interval (CI)]. No events are observed in the DSNB search region, and we set an improved upper bound on the ${\nu }_e$ component of the DSNB flux of ${\mathrm{\Phi }}_{{\nu }_e}^{\mathrm{DSNB}}<19{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$ (90% CI) in the energy range $22.9<E_{\nu }<36.9\mathrm{MeV}$.

I discuss the possibility of estimating the shift $\delta \mathrm{\Delta }\alpha (M_Z^2)$ on the running of the EM-coupling to the $M_Z$ scale, induced by the discrepancy $\mathrm{\Delta }{a}_{\mu }$ between two precise determinations of the hadronic vacuum polarization contribution to $g_{\mu }-2$. It is shown that the size of $\mathrm{\Delta }{a}_{\mu }$ implies rigorous bounds on the $\delta \mathrm{\Delta }\alpha (M_Z^2)$-shift. Any extra contribution to this minimal shift necessarily depends on the specific shape of the underlying spectral function $\frac{1}{\pi }\mathrm{Im}\mathrm{\Delta }(t)$ responsible for the $\mathrm{\Delta }{a}_{\mu }$-discrepancy. I show that, in the case of a quark model, the total $\mathrm{\Delta }\alpha (M_Z^2)$-shift remains small. I also discuss the scenario where $\frac{1}{\pi }\mathrm{Im}\mathrm{\Delta }(t)$ is a constant in a finite $t$-region and show that in this case, up to a $t_{\max }\precsim 5{\mathrm{GeV}}^2$, the size of the total $\delta \mathrm{\Delta }{\alpha }_{\mathrm{had}}^{(5)}(M_Z^2)$-shift, remains below or of the order of the present error value on $\mathrm{\Delta }{\alpha }_{\mathrm{had}}^{(5)}(M_Z^2)$.

The electromagnetic form factors of octet baryons are investigated with the nonlocal chiral effective theory. The nonlocal interaction generates both the regulator, which makes the loop integral convergent, and the $Q^2$ dependence of form factors at tree level. Both octet and decuplet intermediate states are included in the one-loop calculation. The momentum dependence of baryon form factors is studied up to $1{\mathrm{GeV}}^2$ with the same number of parameters as for the nucleon form factors. The obtained magnetic moments of all the octet baryons as well as the radii are in good agreement with the experimental data and/or lattice simulation.

The minimal type-I seesaw framework with texture-zero Yukawa and mass matrices inspired by Occam’s razor is incompatible with normally ordered neutrino masses (currently preferred by data) when lepton mixing originates solely from the neutrino sector. Moreover, the lightest right-handed neutrino mass required to generate the observed baryon asymmetry of the Universe via leptogenesis ($M_1\sim {10}^{14}\mathrm{GeV}$) is in conflict with vanilla scenarios for (Peccei-Quinn) axion dark matter where the reheating temperature of the Universe is typically below ${10}^{12}\mathrm{GeV}$. In this work, we present a new Occam’s razor setup which overcomes these problems by including charged-lepton mixing parametrized by a single angle, which is predicted to be very close to the quark Cabibbo angle. Furthermore, the atmospheric mixing angle lies in the second octant and the leptogenesis scale is lowered to $\sim 5.5\times {10}^{10}\mathrm{GeV}$, lifting the tension with the axion dark-matter hypothesis.

We determine the nucleon axial, scalar and tensor charges within lattice quantum chromodynamics including all contributions from valence and sea quarks. We analyze three gauge ensembles simulated within the twisted mass formulation at approximately physical value of the pion mass. Two of these ensembles are simulated with two dynamical light quarks and lattice spacing $a=0.094\mathrm{fm}$ and the third with $a=0.08\mathrm{fm}$ includes in addition the strange and charm quarks in the sea. After comparing the results among these three ensembles, we quote as final values our most accurate analysis using the latter ensemble. For the nucleon isovector axial charge we find 1.286(23) in agreement with the experimental value. We provide the flavor decomposition of the intrinsic spin $\frac{1}{2}\mathrm{\Delta }{\mathrm{\Sigma }}^q$ carried by quarks in the nucleon obtaining for the up, down, strange and charm quarks $\frac{1}{2}\mathrm{\Delta }{\mathrm{\Sigma }}^u=0.431(8)$, $\frac{1}{2}\mathrm{\Delta }{\mathrm{\Sigma }}^d=-0.212(8)$, $\frac{1}{2}\mathrm{\Delta }{\mathrm{\Sigma }}^s=-0.023(4)$ and $\frac{1}{2}\mathrm{\Delta }{\mathrm{\Sigma }}^c=-0.005(2)$, respectively. The corresponding values of the tensor and scalar charges for each quark flavor are also evaluated providing valuable input for experimental searches for beyond the standard model physics. In addition, we extract the nucleon $\sigma$-terms and find for the light quark content ${\sigma }_{\pi N}=41.6(3.8)\mathrm{MeV}$ and for the strange ${\sigma }_s=45.6(6.2)\mathrm{MeV}$. The y-parameter that is used in phenomenological studies we find $y=0.078(7)$.

We study the weak decay of the ${\mathrm{\Lambda }}_b$ baryon into $J/\psi \varphi \mathrm{\Lambda }$, a process that is particularly well suited to analyze the physics of some of the recently observed or theoretically predicted exotic hadrons, as one expects to see their signature in all three final two-body channels. In the $J/\psi \varphi$ invariant mass spectrum we study the interplay between the $X(4140)$ and the $X(4160)$ resonances. The $J/\psi \mathrm{\Lambda }$ mass spectrum may help to identify the strange partner of the hidden-charm pentaquark recently observed by the LHCb collaboration, the existence of which has been predicted by a chiral unitary approach. We conclude that this strange pentaquark has a good chance of experimental detection if it is present in the range between 4450–4500 MeV. Finally, in the $\varphi \mathrm{\Lambda }$ spectrum we expect a contribution from a dynamically generated resonance at around 2160 MeV, but with the present model parameters there is little chance for its experimental detection.

We study non-Abelian vortex strings in four-dimensional (4D) $\mathcal{N}=2$ supersymmetric QCD with the $\mathrm{U}(N=2)$ gauge group and $N_f=4$ flavors of quark hypermultiplets. It has recently been shown that these vortices behave as critical superstrings. The spectrum of closed string states in the associated string theory was found and interpreted as a spectrum of hadrons in 4D $\mathcal{N}=2$ supersymmetric QCD. In particular, the lowest string state appears to be a massless Bogomol’nyi-Prasad-Sommerfield (BPS) “baryon.” Here we show the occurrence of this stringy baryon using a purely field-theoretic method. To this end we study the conformal world-sheet theory on the non-Abelian string—the so-called weighted $\mathcal{N}=(2,2)$ supersymmetric $\mathbb{C}\mathbb{P}$ model. Its target space is given by the six-dimensional noncompact Calabi-Yau space $Y_6$, the conifold. We use a mirror description of the model to study the BPS kink spectrum and its transformations on curves (walls) of marginal stability. Then we use the 2D-4D correspondence to show that the deformation of the complex structure of the conifold is associated with the emergence of a nonperturbative Higgs branch in 4D theory which opens up at strong coupling. The modulus parameter on this Higgs branch is the vacuum expectation value of the massless BPS baryon previously found in string theory.

The COHERENT experiment is well poised to test sub-GeV dark matter models using detectors sensitive to coherent elastic neutrino-nucleus scattering (CEvNS) in the ${\pi }^{+}$ decay-at-rest ($\pi$-DAR) neutrino beam produced by the Spallation Neutron Source. We show a planned 750-kg single-phase liquid argon scintillation detector would place leading limits on scalar light dark matter models for dark matter particles produced through vector and leptophobic portals in the absence of other effects beyond the standard model. The characteristic timing profile of a $\pi$-DAR beam allows a unique opportunity for constraining systematic uncertainties on the standard model background using a time window where dark matter signal is not expected, enhancing expected sensitivity. Additionally, we discuss future prospects which show that an on-axis CEvNS detector would probe the thermal abundance for a scalar dark matter candidate for all couplings ${\alpha }^{\prime }\le 1$ for 15 MeV dark matter with just 1.0 tonne-yr of exposure with increased exposure testing a wider range of dark matter masses and spins.

Extending our previous analysis, we study the interior of a Schwarzschild black hole derived from a partial gauge fixing of the full loop quantum gravity Hilbert space, this time including the inverse volume and coherent state subleading corrections. Our derived effective Hamiltonian differs crucially from the ones introduced in the minisuperspace models. This distinction is reflected in the class of homogeneous bouncing geometries that replace the classical singularity and are labeled by a set of quantum parameters associated with the structure of coherent states used to derive the effective Hamiltonian. By fixing these quantum parameters through geometrical considerations, the post-bounce interior geometry reveals a high sensitivity to the value of the Barbero–Immirzi parameter $\gamma$. Surprisingly, we find that $\gamma \approx 0.274$ results in an asymptotically de Sitter geometry in the interior region, where now a cosmological constant is generated purely from quantum gravitational effects. The striking fact is the exact coincidence of this value for $\gamma$ with the one derived from the SU(2) black hole entropy calculations in loop quantum gravity. The emergence of this value in two entirely unrelated theoretical frameworks and computational setups is strongly suggestive of deep ties between the area gap in loop quantum gravity, black hole physics, and the observable Universe. In connection to the latter, we point out an intriguing relation between the measured value of the cosmological constant and the observed mass in the Universe from a proposal for a spin quantum number renormalization effect associated to the microscopic dynamics.

Entropy and energy are found to be closely tied on our quest for quantum gravity. We point out an interesting connection between the recently proposed outer entropy, a coarse-grained entropy defined for a compact spacetime domain motivated by the holographic duality, and the Bartnik-Bray quasilocal mass long known in the mathematics community. In both scenarios, one seeks an optimal spacetime fill-in of a given closed, connected, spacelike, codimension-two boundary. We show that for an outer-minimizing mean-convex surface, the Bartnik-Bray inner mass matches exactly with the irreducible mass corresponding to the outer entropy. The equivalence implies that the area laws derived from the outer entropy are mathematically equivalent as the monotonicity property of the quasilocal mass. It also gives rise to new bounds between entropy and the gravitational energy, which naturally gives the gravitational counterpart to Wall’s ant conjecture. We also observe that the equality can be achieved in a conformal flow of metrics, which is structurally similar to the Ceyhan-Faulkner proof of the ant conjecture. We compute the small sphere limit of the outer entropy and it is proportional to the bulk stress tensor as one would expect for a quasilocal mass. Last, we discuss some implications of taking quantum matter into consideration in the semiclassical setting.

We study the effects of motion, on the amount of coherence extracted onto an Unruh-DeWitt detector, modeled as a two-level system, when it interacts with a massless scalar coherent field in $1+1$ Minkowski spacetime. We observe that compared to a detector at rest, for certain values of the initial energy of the field and the duration of the interaction, the amount extracted is larger for a detector moving with constant speed or uniform acceleration. This “swelling” of coherence becomes more intense for increasing values of its velocity and acceleration, and is mostly observed for short interaction durations, when the energy of the field is larger compared to that of the detector, and for longer interaction durations but smaller field energies. As a consequence, the rate at which coherence is lost, is sometimes slower for a moving detector than for a detector at rest.

The entanglement harvesting protocol is an operational way to probe vacuum entanglement. This protocol relies on two atoms, modelled by Unruh-DeWitt detectors, that are initially unentangled. These atoms then interact locally with the field and become entangled. If the atoms remain spacelike separated, any entanglement between them is a result of entanglement that is “harvested” from the field. Thus, quantifying this entanglement serves as a proxy for how entangled the field is across the regions in which the atoms interacted. Using this protocol, it is demonstrated that while the transition probability of an individual inertial atom is unaffected by the presence of a gravitational wave, the entanglement harvested by two atoms depends sensitively on the frequency of the gravitational wave, exhibiting novel resonance effects when the energy gap of the detectors is tuned to the frequency of the gravitational wave. This suggests that the entanglement signature left by a gravitational wave may be useful in characterizing its properties, and potentially useful in exploring the gravitational-wave memory effect and gravitational-wave induced decoherence.

We present a new open-source code that calculates one-loop power spectra and cross spectra for matter fields and biased tracers in real and redshift space. These spectra incorporate all ingredients required for a direct application to data: nonlinear bias and redshift-space distortions, infrared resummation, counterterms, and the Alcock-Paczynski effect. Our code is based on the Boltzmann solver class and inherits its advantageous properties: user friendliness, ease of modification, high speed, and simple interface with other software. We present detailed descriptions of the theoretical model, the code structure, approximations, and accuracy tests. A typical end-to-end run for one cosmology takes 0.3 seconds, which is sufficient for Markov chain Monte Carlo parameter extraction. As an example, we apply the code to the Baryon Oscillation Spectroscopic Survey (BOSS) data and infer cosmological parameters from the shape of the galaxy power spectrum.

We study the emergence of entropy in gravitational production of dark matter particles, ultralight scalars minimally coupled to gravity and heavier fermions, from inflation to radiation domination. Initial conditions correspond to dark matter fields in their Bunch-Davies vacua during inflation. The “out” states are correlated particle-antiparticle pairs, and their distribution function is found in both cases. In the adiabatic regime the density matrix features rapid decoherence by dephasing from interference effects in the basis of out particle states, effectively reducing it to a diagonal form with a concomitant von Neumann entropy. We show that it is exactly the entanglement entropy obtained by tracing over one member of the correlated pairs. Remarkably, for both statistics the entanglement entropy is similar to the quantum kinetic entropy in terms of the distribution function with noteworthy differences stemming from pair correlations. The entropy and the kinetic-fluid form of the energy-momentum tensor all originate from decoherence of the density matrix. For ultralight scalar dark matter, the distribution function peaks at low momentum $\propto 1/k^3$ and the specific entropy is $\ll 1$. This is a hallmark of a condensed phase but with vanishing field expectation value. For fermionic dark matter the distribution function is nearly thermal and the specific entropy is $\mathcal{O}(1)$ which is typical of a thermal species. We argue that the functional form of the entanglement entropy is quite general and applies to alternative production mechanisms such as parametric amplification during reheating.

We study an impact of asymmetric dark matter on properties of the neutron stars and their ability to reach the two solar masses limit, which allows us to present a new range of masses of dark matter particles and their fractions inside the star. Our analysis is based on the observational fact of the existence of two pulsars reaching this limit and on the theoretically predicted reduction of the neutron star maximal mass caused by the accumulation of dark matter in its interior. We also demonstrate that light dark matter particles with masses below 0.2 GeV can create an extended halo around the neutron star leading not to decrease, but to increase of its visible gravitational mass. By using recent results on the spatial distribution of dark matter in the Milky Way, we present an estimate of its fraction inside the neutron stars located in the Galaxy center. We show how the detection of a $2M_{\odot }$ neutron star in the most central region of the Galaxy will impose an upper constraint on the mass of dark matter particles of $\sim 60\mathrm{GeV}$. Future high precision measurements of the neutron stars maximal mass near the Galactic center, will put a more stringent constraint on the mass of the dark matter particle. This last result is particularly important to prepare ongoing, and future radio and x-ray surveys.

The detection of high-energy neutrino coincident with the blazar TXS $0506+056$ provides a unique opportunity to test Lorentz invariance violation (LIV) in the neutrino sector. Thanks to the precisely measured redshift, i.e., $z=0.3365$, the comoving distance of the neutrino source is determined. In this work, we obtain and discuss the constraints on the superluminal neutrino velocity ${\delta }_{\nu }$ and the LIV by considering the energy loss of superluminal neutrino during propagation. Given superluminal electron velocity (${\delta }_e\ge 0$), a very stringent constraint on superluminal neutrino velocity can be reached, i.e., ${\delta }_{\nu }\lesssim 1.3\times {10}^{-18}$, corresponding to the quantum gravity (QG) scale $M_{\mathrm{QG},1}\gtrsim 5.7\times {10}^3{M}_{\mathrm{Pl}}$ and $M_{\mathrm{QG},2}\gtrsim 9.3\times {10}^{-6}{M}_{\mathrm{Pl}}$ for linear (quadratic) LIV, which are $\sim 12$ orders of magnitude tighter for linear LIV and $\sim 9$ orders tighter for quadratic LIV compared to the time-of-flight constraint from MeV neutrinos of SN 1987A. While given the subluminal electron velocity, a weaker constraint on the superluminal neutrino velocity is obtained, i.e., ${\delta }_{\nu }\lesssim 8\times {10}^{-17}$, which is consistent with the conclusions of previous works. We also study the neutrino detection probability due to the distortion of neutrino spectral shape during propagation, which gives slightly weaker constraints than above by a factor of $\sim 2$.

The development of single charge resolving, macroscopic silicon detectors has opened a window into rare processes at the $\mathcal{O}(\mathrm{eV})$ scale. In order to reconstruct the energy of a given event, or model the charge signal obtained for a given amount of energy absorbed by the electrons in a detector, an accurate charge yield model is needed. In this paper we review existing measurements of charge yield in silicon, focusing in particular on the region below 1 keV. We highlight a calibration gap between 12–50 eV (referred to as the “UV-gap”) and employ a phenomenological model of impact ionization to explore the likely charge yield in this energy regime. Finally, we explore the impact of variations in this model on a test case, that of dark matter scattering off electrons, to illustrate the scientific impact of uncertainties in charge yield.

We present the first calculations of two-point two-loop form factors (FFs) with a two identical operators insertion in maximally supersymmetric Yang-Mills theory. In this article, we consider the supersymmetry protected half-BPS primary and unprotected Konishi operators. Unlike the FFs of a single operator insertion of the half-BPS primary, the FFs involving two half-BPS operators are found to contain lower transcendentality weight terms in addition to the highest ones. Moreover, in contrast to Sudakov FFs, the highest weight terms of the FFs of a double half-BPS no longer match with that of a double Konishi. We also find that the principle of maximal transcendentality, which dictates the presence of identical highest weight terms in the scalar FFs of half-BPS and quark/gluon FFs in QCD, does not hold true anymore for insertions of two identical operators. We discover the absence of any additional ultraviolet counterterm that could arise from the contact interaction between two composite operators.