The mixing of neutral mesons is sensitive to some of the highest scales probed in laboratory experiments. In light of the planned LHCb Upgrade II, a possible upgrade of Belle II, and the broad interest in flavor physics in the tera-$Z$ phase of the proposed FCC-ee program, we study constraints on new physics contributions to $B_d$ and $B_s$ mixings which can be obtained in these benchmark scenarios. We explore the limitations of this program, and identify the measurement of $|V_{cb}|$ as one of the key ingredients in which progress beyond current expectations is necessary to maximize future sensitivity. We speculate on possible solutions to this bottleneck. Given the current tension with the standard model (SM) in semileptonic $B$ decays, we explore how its resolution may impact the search for new physics in mixing. Even if new physics has the same Cabibbo-Kobayashi-Maskawa and loop suppressions of flavor changing processes as the SM, the sensitivity will reach 2 TeV, and it can be much higher if any SM suppressions are lifted. We illustrate the discovery potential of this program.

We present an extension of the JHUGen and MELA framework, which includes an event generator and library for the matrix element analysis. It enables simulation, optimal discrimination, reweighting techniques, and analysis of a bosonic resonance and the triple and quartic gauge boson interactions with the most general anomalous couplings. The new features, which become especially relevant at the current stage of LHC data taking, are the simulation of gluon fusion and vector boson fusion in the off-shell region, associated $ZH$ production at NLO QCD including the $gg$ initial state, and the simulation of a second spin-zero resonance. We also quote translations of the anomalous coupling measurements into constraints on dimension-six operators of an effective field theory. Some of the new features are illustrated with projections for experimental measurements with the full LHC and HL-LHC datasets.

A number of different effects of the violation of the equivalence principle (VEP), taken as subleading mechanism of neutrino flavor oscillation, are examined within the framework of the DUNE experiment. We study the possibility of obtaining a misleading neutrino oscillation parameter region caused by our unawareness of VEP. Additionally, we evaluate the impact on the measurement of $CP$ violation and the distinction of neutrino mass hierarchy at DUNE. Besides, limits on VEP for a wide variety of textures of the matrix that connects neutrino gravity eigenstates to flavor eigenstates are imposed. An extra task of our study is to set limits on Hamiltonian added terms considering different energy dependencies ($E^{d-3}$, with $d=3$, 4, 5, 6) that can be associated to the usual Lorentz violating terms defined in the Standard Model extension Hamiltonian. In order to understand our results, approximated analytical three neutrino oscillation probability formulae are derived.

We propose a new scenario where dark matter belongs to a secluded sector coupled to the Standard Model through energy-momentum tensors. Our model is motivated by constructions where gravity emerges from a hidden sector, the graviton being identified by the kinetic term of the fields in the secluded sector. Supposing that the lighter particle of the secluded sector is the dark component of the Universe, we show that we can produce it in a sufficiently large amount despite the suppressed couplings of the theory, thanks to large temperatures of the thermal bath in the early stage of the Universe.

Axionlike particles $a$ (ALPs) that couple to the Standard Model gauge fields could be observed in the high-energy photon scattering $\gamma N\to Na$ off nuclei followed by the $a\to \gamma \gamma$ decay. In the present paper we describe the calculation of the ALP production cross section and the properties of this production. The cross section formulas are implemented in the program for the simulation of events in the NA64 experiment, the active electron beam dump facility at the CERN Super Proton Synchrotron. We study the prospects of the NA64 experiment to search for ALP in the $10\mathrm{MeV}\lesssim m_a\lesssim 100\mathrm{MeV}$ mass range for the statistics corresponding to up to $5\times {10}^{12}$ electrons on target.

We study the electromagnetic conductivity of QGP in a magnetic background by lattice simulations with $N_f=2+1$ dynamical rooted 2-stout smeared staggered fermions at the physical point. We study the correlation functions of the electromagnetic currents at $T=200$, 250 MeV and use the Tikhonov approach to extract the conductivity. The conductivity is found to rise with the magnetic field in the parallel direction and to decrease in the transverse direction, giving evidence for both the chiral magnetic effect and the magnetoresistance phenomenon in QGP. We also estimate the chiral charge relaxation time in QGP.

We show that a recently derived alternative form of the relativistic three-particle quantization condition for identical particles can be rewritten in terms of the R matrix introduced to give a unitary representation of the infinite-volume three-particle scattering amplitude. Combined with earlier work, this shows the equivalence of the relativistic effective field theory approach of Refs. [M. T. Hansen and S. R. Sharpe, Phys. Rev. D 90, 116003 (2014); M. T. Hansen and S. R. Sharpe, Phys. Rev. D 92, 114509 (2015)] and the “finite-volume unitarity” approach of Refs. [M. Mai and M. Döring, Eur. Phys. J. A 53, 240 (2017); M. Mai and M. Döring, Phys. Rev. Lett. 122, 062503 (2019)]. It also provides a generalization of the latter approach to arbitrary angular momenta of two-particle subsystems.

The pentaquark states, $P_c(4312)$, $P_c(4440)$, and $P_c(4450)$, can be nicely arranged into a multiplet of seven molecules of ${\overline{D}}^{(*)}{\mathrm{\Sigma }}_c^{(*)}$ dictated by heavy quark spin symmetry, while the ${\mathrm{\Xi }}_{cc}^{(*)}{\mathrm{\Sigma }}_c^{(*)}$ system can be related to the ${\overline{D}}^{(*)}{\mathrm{\Sigma }}_c^{(*)}$ system via heavy antiquark diquark symmetry. In this work, we employ the one-boson exchange model to study the interactions between ${\mathrm{\Xi }}_{cc}^{(*)}$ and ${\mathrm{\Sigma }}_c^{(*)}$ with constraints from the pentaquark system. We show that a multiplet of ten triply charmed dibaryons emerge naturally in the isospin-$1/2$ sector, while only three appear in the isospin-$3/2$ sector. In addition, we study their heavy quark flavor partners. Ten triply bottom diybaryons are found in the isospin-$1/2$ sector, while only nine are likely in the isospin-$3/2$ sector. Furthermore, the predicted mass splitting between the $0^{+}$ ${\mathrm{\Xi }}_{cc}{\mathrm{\Sigma }}_c$ state and its $1^{+}$ counterpart is found to be consistent with the correlation implied by heavy antiquark diquark symmetry recently pointed out in Pan et al..

We study the single hadron inclusive production in the forward rapidity region in proton-nucleus collisions. We find the longstanding negative cross section at next-to-leading-order (NLO) is driven by the large negative threshold logarithmic contributions. We established a factorization theorem for resumming these logarithms with systematically improvable accuracy within the color glass condensate formalism. We demonstrate how the threshold leading logarithmic accuracy can be realized by a suitable scale choice in the NLO results. The NLO spectrums with the threshold logarithms resummed remain positive and impressive agreements with experimental data are observed.

We report the first search for the $K_L\to {\pi }^0\gamma$ decay, which is forbidden by Lorentz invariance, using the data from 2016 to 2018 at the J-PARC KOTO experiment. With a single event sensitivity of $(7.1\pm 0.3_{\mathrm{stat}}\pm 1.6_{\mathrm{syst}})\times {10}^{-8}$, no candidate event was observed in the signal region. The upper limit on the branching fraction was set to be $1.7\times {10}^{-7}$ at the 90% confidence level.

There exists a certain argument that in even dimensions, scale invariant quantum field theories are conformal invariant. We may try to extend the argument in $2n+\epsilon$ dimensions, but the naive extension has a small loophole, which indeed shows an obstruction in nonlinear sigma models in $2+\epsilon$ dimensions. Even though it could have failed due to the loophole, we show that scale invariance does imply conformal invariance of nonlinear sigma models in $2+\epsilon$ dimension from the seminal work by Perelman on the Ricci flow.

We show that the maximum and the minimum mass of merging neutron stars can be estimated with upcoming gravitational wave observations. We simulate populations of binary neutron star signals and model their mass distribution including upper and lower cutoffs. The lower (upper) limit can be measured to $\sim 0.2$ $(0.1)M_{\odot }$ with 50 detections if the mass distribution supports neutron stars with masses close to the cutoffs. The upper mass limit informs about the high-density properties of the neutron star equation of state, while the lower limit signals the divide between neutron stars and white dwarfs.

We study a coupled dark energy scenario in which a massive vector field $A_{\mu }$ with broken $U(1)$ gauge symmetry interacts with the four-velocity $u_c^{\mu }$ of cold dark matter (CDM) through the scalar product $Z=-u_c^{\mu }{A}_{\mu }$. This new coupling corresponds to the momentum transfer, so that the background vector and CDM continuity equations do not have explicit interacting terms analogous to the energy exchange. Hence the observational preference of uncoupled generalized Proca theories over the $\mathrm{\Lambda }\mathrm{CDM}$ model can be still maintained at the background level. Meanwhile, the same coupling strongly affects the evolution of cosmological perturbations. While the effective sound speed of CDM vanishes, the propagation speed and no-ghost condition of a longitudinal scalar of $A_{\mu }$ and the CDM no-ghost condition are subject to nontrivial modifications by the $Z$ dependence in the Lagrangian. We propose a concrete dark energy model and show that the gravitational interaction on scales relevant to the linear growth of large-scale structures can be smaller than the Newton constant at low redshifts. This leads to the suppression of growth rates of both CDM and total matter density perturbations, so our model allows an interesting possibility for reducing the tension of matter density contrast ${\sigma }_8$ between high- and low-redshift measurements.

The relativistic Cowling approximation, where the metric perturbations are neglected during the fluid oscillations, is often adopted for considering the gravitational waves from the protoneutron stars (PNSs) provided via core-collapse supernova explosions. In this study, we evaluate how the Cowling approximation works well by comparing the frequencies with the Cowling approximation to those without the approximation. Then, we find that the behavior of the frequencies with the approximation is qualitatively the same way as that without the approximation, where the frequencies with the approximation can totally be determined within $\sim 20\%$ accuracy. In particular, the fundamental mode with the Cowling approximation is overestimated. In addition, we also discuss the damping time of various eigenmodes in gravitational waves from the PNSs, where the damping time for the PNSs before the avoided crossing between the $f$- and $g_1$-modes, is quite different from that for cold neutron stars, but it is more or less similar to that for cold neutron stars in the later phase. The damping time is long enough compared to the typical time interval of short-Fourier transformation that often used in the analysis, and that ideally guarantees the validity of the transformation.

The neutrino floor is a barrier in the parameter space of weakly interacting massive particles (WIMPs) below which discovery is impeded due to an almost irreducible background of neutrinos. Directional gas time projection chambers could discriminate against solar neutrinos, relevant for WIMP masses $\lesssim 10\mathrm{GeV}$. At higher masses $\gtrsim 100\mathrm{GeV}$ the floor is set by the background of atmospheric neutrinos. Probing below this part of the floor would require very large target exposures. Since gas-based detectors would be prohibitively large at this scale, we instead reevaluate the prospects for liquid noble experiments to probe below the neutrino floor. We combine all potential methods of subtracting the neutrino background to determine how much of this difficult to reach, but well-motivated, parameter space it is feasible to reach. Most notably, we quantify whether a proposed directional signal in xenon and argon experiments called “columnar recombination” can help in this task. We find that even if the strength of this effect is amplified beyond current experimental results, the quantity of directional information contained in the recombination signal is too low to realistically discriminate against the atmospheric neutrino background. Instead, benefiting from the refined measurements of neutrino fluxes by experiments such as DUNE and JUNO will be the most practical means to push direct WIMP searches below the neutrino floor. For an ultimate global coordination of xenon and argon experiments, we show that the neutrino floor is a surmountable barrier. The direct detection of 100 GeV-scale supersymmetric WIMPs may, eventually, be within reach.

Under the assumption of separable interactions, we illustrate how the few-body quantization condition may be formulated in terms of phase shifts, in general, which may be useful for describing and modeling few-body resonances in finite volume.

Based on $e^{+}{e}^{-}$ collision data sample corresponding to an integrated luminosity of $2.93{\mathrm{fb}}^{-1}$ taken at a center-of-mass energy of 3.773 GeV by the BESIII detector, we report the measurements of the absolute branching fractions of $D^0\to K^{+}{K}^{-}{\pi }^0{\pi }^0$, $D^0\to K_S^0{K}_S^0{\pi }^{+}{\pi }^{-}$, $D^0\to K_S^0{K}^{-}{\pi }^{+}{\pi }^0$, $D^0\to K_S^0{K}^{+}{\pi }^{-}{\pi }^0$, $D^{+}\to K^{+}{K}^{-}{\pi }^{+}{\pi }^0$, $D^{+}\to K_S^0{K}^{+}{\pi }^0{\pi }^0$, $D^{+}\to K_S^0{K}^{-}{\pi }^{+}{\pi }^{+}$, $D^{+}\to K_S^0{K}^{+}{\pi }^{+}{\pi }^{-}$, and $D^{+}\to K_S^0{K}_S^0{\pi }^{+}{\pi }^0$. The decays $D^0\to K^{+}{K}^{-}{\pi }^0{\pi }^0$, $D^0\to K_S^0{K}^{-}{\pi }^{+}{\pi }^0$, $D^0\to K_S^0{K}^{+}{\pi }^{-}{\pi }^0$, $D^{+}\to K_S^0{K}_S^0{\pi }^{+}{\pi }^0$, and $D^{+}\to K_S^0{K}^{+}{\pi }^0{\pi }^0$ are observed for the first time. The branching fractions of the decays $D^0\to K_S^0{K}_S^0{\pi }^{+}{\pi }^{-}$, $D^{+}\to K^{+}{K}^{-}{\pi }^{+}{\pi }^0$, $D^{+}\to K_S^0{K}^{-}{\pi }^{+}{\pi }^{+}$, and $D^{+}\to K_S^0{K}^{+}{\pi }^{+}{\pi }^{-}$ are measured with improved precision compared to the world-average values.

Models proposed to explain recently discovered heavy-light four-quark states already assume certain internal structures, i.e., the (anti)quark constituents are grouped into diquark/antidiquark clusters, heavy-meson/light-meson clusters (hadrocharmonium) or heavy-light meson molecules. We propose and use an approach to four-quark states based on Dyson-Schwinger and Bethe-Salpeter equations that has the potential to discriminate between these models. We study the masses of heavy-light $cq\overline{q}\overline{c}$ and $cc\overline{q}\overline{q}$ four-quark states with $q=u$, $d$, $s$ and quantum numbers $I(J^{PC})=0(1^{++}),1(1^{+-}),0(0^{++})$ and $1(0^{+}),0(1^{+}),1(1^{+})$. We identify the dominant components of the ground states with these quantum numbers and suggest candidates for corresponding experimental states. Most notably, we find strong heavy-light meson-meson and negligible diquark-antidiquark components in all $cq\overline{q}\overline{c}$ states, whereas for $cc\overline{q}\overline{q}$ states diquarks are present. A potential caveat in the $I=0$ channels is the necessary but costly inclusion of $c\overline{c}$ components which is relegated to future work.