We apply effective field theory methods to compute bino-nucleon scattering, in the case where tree-level interactions are suppressed and the leading contribution is at loop order via heavy flavor squarks or sleptons. We find that leading log corrections to fixed-order calculations can increase the bino mass reach of direct detection experiments by a factor of 2 in some models. These effects are particularly large for the bino-sbottom coannihilation region, where bino dark matter as heavy as 5–10 TeV may be detected by near future experiments. For the case of stop- and selectron-loop mediated scattering, an experiment reaching the neutrino background will probe thermal binos as heavy as 500 and 300 GeV, respectively. We present three key examples that illustrate in detail the framework for determining weak scale coefficients, and for mapping onto a low-energy theory at hadronic scales, through a sequence of effective theories and renormalization group evolution. For the case of a squark degenerate with the bino, we extend the framework to include a squark degree of freedom at low energies using heavy particle effective theory, thus accounting for large logarithms through a “heavy-light current.” Benchmark predictions for scattering cross sections are evaluated, including complete leading order matching onto quark and gluon operators, and a systematic treatment of perturbative and hadronic uncertainties.

We present a high statistics study of the pion and nucleon light and strange quark sigma terms using $N_f=2$ dynamical nonperturbatively improved clover fermions with a range of pion masses down to $m_{\pi }\sim 150\mathrm{MeV}$ and several volumes, $L{m}_{\pi }=3.4$ up to 6.7, and lattice spacings, $a=0.06–0.08\mathrm{fm}$, enabling a study of finite volume and discretization effects for $m_{\pi }\gtrsim 260\mathrm{MeV}$. Systematics are found to be reasonably under control. For the nucleon we obtain ${\sigma }_{\pi N}=35(6)\text{MeV}$ and ${\sigma }_s=35(12)\mathrm{MeV}$, or equivalently in terms of the quark fractions, $f_{T_u}=0.021(4)$, $f_{T_d}=0.016(4)$ and $f_{T_s}=0.037(13)$, where the errors include estimates of both the systematic and statistical uncertainties. These values, together with perturbative matching in the heavy quark limit, lead to $f_{T_c}=0.075(4)$, $f_{T_b}=0.072(2)$ and $f_{T_t}=0.070(1)$. In addition, through the use of the (inverse) Feynman-Hellmann theorem our results for ${\sigma }_{\pi N}$ are shown to be consistent with the nucleon masses determined in the analysis. For the pion we implement a method which greatly reduces excited state contamination to the scalar matrix elements from states traveling across the temporal boundary. This enables us to demonstrate the Gell-Mann-Oakes-Renner expectation ${\sigma }_{\pi }=m_{\pi }/2$ over our range of pion masses.

We study the ${\mathrm{\Lambda }}_b\to J/\psi K^0\mathrm{\Lambda }$ reaction considering both the $K^0\mathrm{\Lambda }$ interaction with its coupled channels and the $J/\psi \mathrm{\Lambda }$ interaction. The latter is described by taking into account the fact that there are predictions for a hidden-charm state with strangeness that couples to $J/\psi \mathrm{\Lambda }$. By using the coupling of the resonance to $J/\psi \mathrm{\Lambda }$ from these predictions, we show that a neat peak can be observed in the $J/\psi \mathrm{\Lambda }$ invariant mass distribution, rather stable under changes of unknown magnitudes. In some cases, one finds a dip structure associated to that state, but a signal of the state shows up in the $J/\psi \mathrm{\Lambda }$ spectrum.

We discuss the possibility that production of final states with bottomonium and light mesons at the peak $\mathrm{\Upsilon }(6S)$ in the $e^{+}{e}^{-}$ annihilation at approximately 11.00 GeV is in fact due to a triangular singularity at the threshold of the heavy meson pair production $B_1(5721)\overline{B}+\mathrm{c}.\mathrm{c}.$ through the process $e^{+}{e}^{-}\to B_1(5721)\overline{B}\to Z_b(10610)\pi$. The presence of the hidden-bottom resonance $Z_b(10610)$ then explains the observed enhanced production of the final channels with both ortho- and para-bottomonium states, $\mathrm{\Upsilon }(nS)\pi \pi$ and $h_b(kP)\pi \pi$. The discussed mechanism also predicts a distinct pattern for production of hidden-bottom states at the $\mathrm{\Upsilon }(6S)$ energy that can be tested by experiment.

We study the masses of the low-lying charm and bottom mesons within the framework of heavy hadron chiral perturbation theory (HHChPT). We work to third order in the chiral expansion, where meson loops contribute. In contrast to previous approaches, we use physical meson masses in evaluating these loops. This ensures that their imaginary parts are consistent with the observed widths of the $D$ mesons. The lowest odd- and even-parity, strange and nonstrange charm mesons provide enough constraints to determine only certain linear combinations of the low-energy constants in the effective Lagrangian. We comment on how lattice QCD could provide further information to disentangle these constants. Then, we use the results from the charm sector to predict the spectrum of odd and even parity of the bottom mesons. The predicted masses from our theory are in good agreement with experimentally measured masses for the case of the odd-parity sector. For the even-parity sector, the $B$-meson states have not yet been observed; thus, our results provide useful information for experimentalists investigating such states. The near degeneracy of nonstrange and strange scalar $B$ mesons is confirmed in our predictions using HHChPT. We show why previous approaches of using HHChPT in studying the mass degeneracy in the scalar states of charm and bottom meson sectors gave unsatisfactory results.

Using a set of rephasing-invariant variables, it is shown that the renormalization group equations for quark mixing parameters can be written in a form that is compact, in addition to having simple properties under flavor permutation. We also found approximate solutions to these equations if the quark masses are hierarchical or nearly degenerate.

We study the problem of estimating the Schwarzschild radius of a massive body using Gaussian quantum probe states. Previous calculations assumed that the probe state remained pure after propagating a large distance. In a realistic scenario, there would be inevitable losses. Here we introduce a practical approach to calculate the quantum Fisher information (QFI) for a quantum probe that has passed through a lossy channel. While for many situations loss means coherent states are optimal, we identify certain situations for which squeezed states have an advantage. We also study the effect of the frequency profile of the wave packet propagating from Alice to Bob. There exists an optimal operating point for a chosen mode profile. In particular, employing a smooth rectangular frequency profile significantly improves the error bound on the Schwarzschild radius compared to a Gaussian frequency profile.

In string theory, higher rank antisymmetric tensor fields appear as massless excitations of closed strings. To date, there is no experimental support in favor of their existence. In a stringy framework, starting from a warped throatlike Klebanov-Strassler geometry, we show that all the massless higher rank antisymmetric tensor fields are heavily suppressed due to the background fluxes leading to their invisibility in our Universe.

We construct effective Lagrangians, and corresponding counting schemes, valid to describe the dynamics of the lowest lying large $N$ stable massive composite state emerging in strongly coupled theories. The large $N$ counting rules can now be employed when computing quantum corrections via an effective Lagrangian description. The framework allows for systematic investigations of composite dynamics of a non-Goldstone nature. Relevant examples are the lightest glueball states emerging in any Yang-Mills theory. We further apply the effective approach and associated counting scheme to composite models at the electroweak scale. To illustrate the formalism we consider the possibility that the Higgs emerges as the lightest glueball of a new composite theory; the large $N$ scalar meson in models of dynamical electroweak symmetry breaking; the large $N$ pseudodilaton useful also for models of near-conformal dynamics. For each of these realizations we determine the leading $N$ corrections to the electroweak precision parameters. The results nicely elucidate the underlying large $N$ dynamics and can be used to confront first principle lattice results featuring composite scalars with a systematic effective approach.

Perfectly conducting boundaries, and their Dirichlet counterparts for quantum scalar fields, predict nonintegrable energy densities. A more realistic model with a finite ultraviolet cutoff yields two inconsistent values for the force on a curved or edged boundary (the “pressure anomaly”). A still more realistic, but still easily calculable, model replaces the hard wall by a power-law potential; because it involves no a posteriori modification of the formulas calculated from the theory, this model should be anomaly free. Here we first set up the formalism and notation for the quantization of a scalar field in the background of a planar soft wall, and we approximate the reduced Green function in perturbative and WKB limits (the latter being appropriate when either the mode frequency or the depth into the wall is sufficiently large). Then we display numerical calculations of the energy density and pressure for the region outside the wall, which show that the pressure anomaly does not occur there. Calculations inside the wall are postponed to later papers, which must tackle the regularization and renormalization of divergences induced by the potential in the bulk region.

We examine the polynomial form of the scattering equations by means of computational algebraic geometry. The scattering equations are the backbone of the Cachazo-He-Yuan (CHY) representation of the S-matrix. We explain how the Bezoutian matrix facilitates the calculation of amplitudes in the CHY formalism, without explicitly solving the scattering equations or summing over the individual residues. Since for $n$-particle scattering the size of the Bezoutian matrix grows only as $(n-3)\times (n-3)$, our algorithm is very efficient for analytic and numeric amplitude computations.

The Cachazo-He-Yuan (CHY) formula for $n$-gluon scattering is known to give the same amplitude as the one obtained from Feynman diagrams, though the former contains neither vertices nor propagators explicitly. The equivalence was shown by indirect means, not by a direct evaluation of the ($n-3$)-dimensional integral in the CHY formula. The purpose of this paper is to discuss how such a direct evaluation can be carried out. There are two basic difficulties in the calculation: how to handle the large number of terms in the reduced Pfaffian, and how to carry out the integrations in the presence of a $\sigma$ dependence much more complicated than the Parke-Taylor form found in a CHY double-color scalar amplitude. We have solved both of these problems, and have formulated a method that can be applied to any $n$. Many examples are provided to illustrate these calculations.

We investigate the transmission of both classical and quantum information between two arbitrary observers in globally hyperbolic spacetimes using a quantum field as a communication channel. The field is supposed to be in some arbitrary quasifree state and no choice of representation of its canonical commutation relations is made. Both sender and receiver possess some localized two-level quantum system with which they can interact with the quantum field to prepare the input and receive the output of the channel, respectively. The interaction between the two-level systems and the quantum field is such that one can trace out the field degrees of freedom exactly and thus obtain the quantum channel in a nonperturbative way. We end the paper determining the unassisted as well as the entanglement-assisted classical and quantum channel capacities.

We raise the analytical knowledge of the eccentricity expansion of the Detweiler-Barack-Sago redshift invariant in a Schwarzschild spacetime up to the 9.5th post-Newtonian order (included) for the $e^2$ and $e^4$ contributions, and up to the 4th post-Newtonian order for the higher eccentricity contributions through $e^{20}$. We convert this information into an analytical knowledge of the effective-one-body radial potentials $\overline{d}(u)$, $\rho (u)$ and $q(u)$ through the 9.5th post-Newtonian order. We find that our analytical results are compatible with current corresponding numerical self-force data.

For a massive vector field with derivative self-interactions, the breaking of the gauge invariance allows the propagation of a longitudinal mode in addition to the two transverse modes. We consider generalized Proca theories with second-order equations of motion in a curved space-time and study how the longitudinal scalar mode of the vector field gravitates on a spherically symmetric background. We show explicitly that cubic-order self-interactions lead to the suppression of the longitudinal mode through the Vainshtein mechanism. Provided that the dimensionless coupling of the interaction is not negligible, this screening mechanism is sufficiently efficient to give rise to tiny corrections to gravitational potentials consistent with solar-system tests of gravity. We also study the quartic interactions with the presence of nonminimal derivative coupling with the Ricci scalar and find the existence of solutions where the longitudinal mode completely vanishes. Finally, we discuss the case in which the effect of the quartic interactions dominates over the cubic one and show that local gravity constraints can be satisfied under a mild bound on the parameters of the theory.

The origin of the ultrahigh-energy particles we receive on Earth from outer space such as EeV cosmic rays and PeV neutrinos remains an enigma. All mechanisms known to us currently make use of electromagnetic interaction to accelerate charged particles. In this paper, we propose a mechanism exclusively based on gravity rather than electromagnetic interaction. We show that it is possible to generate ultrahigh-energy particles starting from particles with moderate energies using the collisional Penrose process in an overspinning Kerr spacetime transcending the Kerr bound only by an infinitesimal amount, i.e., with the Kerr parameter $a=M(1+\epsilon )$, where we take the limit $\epsilon \to 0^{+}$. We consider two massive particles starting from rest at infinity that collide at $r=M$ with divergent center-of-mass energy and produce two massless particles. We show that massless particles produced in the collision can escape to infinity with the ultrahigh energies exploiting the collisional Penrose process with the divergent efficiency $\eta \sim 1/\sqrt{\epsilon }\to \infty$. Assuming the isotropic emission of massless particles in the center-of-mass frame of the colliding particles, we show that half of the particles created in the collisions escape to infinity with the divergent energies, while the proportion of particles that reach infinity with finite energy is minuscule. To a distant observer, ultrahigh-energy particles appear to originate from a bright spot which is at the angular location $\xi \sim 2M/r_{\mathrm{obs}}$ with respect to the singularity on the side which is rotating toward the observer. We compute the spectrum of the high-energy massless particles and show that anisotropy in the emission in the center-of-mass frame leaves a distinct signature on its shape. Since the anisotropy is dictated by the differential cross section of the underlying particle physics process, the observation of the spectrum can constrain the particle physics model and serve as a unique probe into fundamental physics at ultrahigh energies at which particles collide. Thus, the existence of the near-extremal overspinning Kerr geometry in the Universe, either as a transient or permanent configuration, would have deep implications on astrophysics as well as fundamental particle physics.

We study a quantum fermion field inside a cylinder in Minkowski space-time. On the surface of the cylinder, the fermion field satisfies either spectral or MIT bag boundary conditions. We define rigidly-rotating quantum states in both cases, assuming that the radius of the cylinder is sufficiently small that the speed-of-light surface is excluded from the space-time. With this assumption, we calculate rigidly-rotating thermal expectation values of the fermion condensate, neutrino charge current and stress-energy tensor relative to the bounded vacuum state. These rigidly-rotating thermal expectation values are finite everywhere inside and on the surface of the cylinder, and their detailed properties depend on the choice of boundary conditions. We also compute the Casimir divergence of the expectation values of these quantities in the bounded vacuum state relative to the unbounded Minkowski vacuum. We find that the rate of divergence of the Casimir expectation values depends on the conditions imposed on the boundary.

Several recent cosmological analyses have found tension between constraints derived from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS) data and those derived from other data sets, such as the Planck cosmic microwave background (CMB) temperature anisotropies. Similarly, a direct cross-correlation of the CFHTLenS data with Planck CMB lensing data yielded an anomalously low amplitude compared to expectations based on Planck or WMAP-derived cosmological parameters Liu and Hill [Phys. Rev. D 92, 063517 (2015)]. One potential explanation for these results is a multiplicative bias afflicting the CFHTLenS galaxy shape measurements, from which shears are inferred. Simulations are used in the CFHTLenS pipeline to calibrate such biases, but no data-driven constraints have been presented to date. In this paper, we cross-correlate CFHTLenS galaxy density maps with CFHTLenS shear maps and Planck CMB lensing maps to calibrate an additional multiplicative shear bias ($m$) in CFHTLenS (beyond the multiplicative correction that has already been applied to the CFHTLenS galaxy shears), following methods suggested by Vallinotto [Astrophys. J. 759, 32 (2012)], and Das et al. [arXiv:1311.2338]. We analyze three magnitude-limited galaxy samples, finding $2–4\sigma$ evidence for $m<1$ using the deepest sample ($i<24$), while the others are consistent with $m=1$ (no bias). This matches the expectation that the shapes of faint galaxies are the most prone to measurement biases. Our results for $m$ are essentially independent of the assumed cosmology, and only weakly sensitive to assumptions about the galaxy bias. We consider three galaxy bias models, finding in all cases that the best-fit multiplicative shear bias is less than unity (neglecting photometric redshift errors and intrinsic alignment contamination). A value of $m\approx 0.9$ would suffice to reconcile the amplitude of density fluctuations inferred from the CFHTLenS shear two-point statistics with that inferred from Planck CMB temperature data. This scenario is consistent with our results.