The numerical value of the fine-structure constant generally leads to small isospin-breaking effects due to electromagnetism in QCD. This smallness complicates determining isospin breaking from lattice QCD computations that include electromagnetism. One solution to this problem consists of performing computations using larger-than-physical values of the electric charge, and subsequently extrapolating (or interpolating) to the physical value of the fine-structure constant. Motivated by recent lattice $\mathrm{QCD}+\mathrm{QED}$ computations of electromagnetic masses employing this setup, we consider finite-volume effects arising from the use of larger-than-physical electric charges. A modified power-counting scheme, which is based on treating the fine-structure constant as larger than its physical value, is explored. Results for perturbative QED corrections, however, are surprising. Within the framework of nonrelativistic QED, multiloop diagrams exhibit a momentum factorization property that produces exact cancellations. We determine that power-law finite-volume effects vanish at the leading two- and three-loop order, as well as the next-to-leading two-loop order. For larger-than-physical charges, we consequently expect no appreciable volume corrections beyond leading-order QED.

We propose a new order parameter of a $Z_N$ symmetry in SU(N) gauge theories in four dimensional Minkowski space-time, assuming spatial periodic boundary conditions. It is given by $\mathrm{Tr}(P\exp (i{\int }_c{A}_{\mu }d{x}^{\mu }))$, where the spatial path $c$ is taken, for example, along the $x_1$ axis. The parameter vanishes when the $Z_N$ symmetry is preserved. We calculate the contribution of QCD monopoles to the order parameter and show that when the monopoles condense $⟨\mathrm{\Phi }⟩\ne 0$, it vanishes, while it does not vanish when they do not condense. These calculations are performed using a monopole field $\mathrm{\Phi }$ canonically quantized in a model of dual superconductor.

In this paper the dynamical spin effects of the light-front holographic wave functions for light pseudoscalar mesons are studied. These improved wave functions are then confronted with a number of hadronic observables: the decay constants of $\pi$ and $K$ mesons, their $\xi$-moments, the pion-to-photon transition form factor, and the pure annihilation ${\overline{B}}_s\to {\pi }^{+}{\pi }^{-}$ and ${\overline{B}}_d\to K^{+}{K}^{-}$ decays. Taking $f_{\pi }$, $f_K$, and their ratio $f_K/f_{\pi }$ as constraints, we perform a ${\chi }^2$ analysis for the holographic parameters, including the mass scale parameter $\sqrt{\lambda }$ and the effective quark masses, and find that the fitted results are quite consistent with the ones obtained from the light-quark hadronic Regge trajectories. In addition, we also show that the end point divergence appearing in the pure annihilation ${\overline{B}}_s\to {\pi }^{+}{\pi }^{-}$ and ${\overline{B}}_d\to K^{+}{K}^{-}$ decays can be controlled well by using these improved light-front holographic distribution amplitudes.

We present a point-by-point determination of the Sivers distributions from hadron leptoproduction data. The method, which relies on some simple assumptions, is based on the combined analysis of proton and deuteron observables. We make use of the single-spin asymmetries measured by COMPASS in semi-inclusive deep inelastic scattering of 160 GeV muons on transversely polarized proton and deuteron targets.

In this paper, we study the $B\to K^{*}$ transition form factors (TFFs) within the QCD light-cone sum rules (LCSR) approach. Two correlators, i.e., the usual one and the right-handed one, are adopted in the LCSR calculation. The resultant LCSRs for the $B\to K^{*}$ TFFs are arranged according to the twist structure of the $K^{*}$-meson light-cone distribution amplitudes (LCDAs), whose twist-2, twist-3, and twist-4 terms behave quite differently by using different correlators. We observe that the twist-4 LCDAs, though generally small, shall have sizable contributions to the TFFs $A_{1/2}$, $V$, and $T_1$; thus, the twist-4 terms should be kept for a sound prediction. We also observe that, even though different choices of the correlator lead to different LCSRs with different twist contributions, the large correlation coefficients for most of the TFFs indicate that the LCSRs for different correlators are close to each order, not only for their values at the large recoil point $q^2=0$ but also for their ascending trends in the whole $q^2$ region. Such a high degree of correlation is confirmed by their application to the branching fraction of the semileptonic decay $B\to K^{*}{\mu }^{+}{\mu }^{-}$. Thus, a proper choice of correlator may inversely provide a chance for probing uncertain LCDAs; i.e., the contributions from those LCDAs can be amplified to a certain degree via a proper choice of correlator, thus amplifying the sensitivity of the TFFs and, hence, their related observables, to those LCDAs.

Collective excitations of a hot QCD medium are the main focus of this article. The analysis is performed within semiclassical transport theory with isotropic and anisotropic momentum distribution functions for the gluonic and quark-antiquark degrees of freedom that constitutes the hot QCD plasma. The isotropic/equilibrium momentum distributions for gluons and quarks are based on a recent quasiparticle description of hot QCD equations of state. These effective momentum distribution functions for quasigluons and quasiquarks that encode hot QCD medium effects in terms of temperature dependent effective gluon and effective quark fugacities turned out to be isotropic in momentum. The anisotropic distributions are just the extensions of isotropic ones by stretching or squeezing them in one of the directions. The hot QCD medium effects in the model adopted here enter through the effective gluon and quark fugacities along with nontrivial dispersion relations leading to an effective QCD coupling constant. The semiclassical transport theory for computing the gluon polarization for the isotropic distributions (assuming a hot QCD medium as the ultrarelativistic system of gluons and quark/antiquarks) can straightforwardly be extended in the present case. The interactions mainly modify the Debye mass parameter and, in turn, the effective coupling in the medium. These modifications have been seen to modify the collective modes of the hot QCD plasma in a significant way.

In this paper, we present a study to measure the differences between the atmospheric neutrino and antineutrino oscillations in the Iron-Calorimeter detector at the India-based Neutrino Observatory experiment. Charged-current ${\nu }_{\mu }$ and ${\overline{\nu }}_{\mu }$ interactions with the detector under the influence of the Earth matter effect have been simulated for ten years of exposure. The observed ${\nu }_{\mu }$ and ${\overline{\nu }}_{\mu }$ event spectra are separately binned into direction and energy bins, and a ${\chi }^2$ is minimized with respect to each bin to extract the oscillation parameters for ${\nu }_{\mu }$ and ${\overline{\nu }}_{\mu }$ separately. We then present the ICAL sensitivity to confirm a nonzero value of the difference in the atmospheric mass squared of neutrinos and antineutrinos, i.e., $|\mathrm{\Delta }{m}_{32}^2|-|\mathrm{\Delta }{\overline{m^2}}_{32}|$.

We calculate the two-loop contributions from a modified trilinear Higgs self-interaction, ${\kappa }_{\lambda }{\lambda }_{\mathrm{SM}}v{h}^3$, to the electroweak oblique parameters $S$ and $T$. Using the current bounds on $S$ and $T$ from electroweak measurements, we find the 95% C.L. constraint on the modified trilinear coupling to be $-14.0\le {\kappa }_{\lambda }\le 17.4$. The largest effects on $S$ and $T$ arise from two insertions of the modified trilinear coupling that result in $T/S\simeq -3/2$; remarkably, this is nearly parallel to the axis of the tightest experimental constraint in the $S\text{−}T$ plane. No contributions to $S$ and $T$ arise from a modified Higgs quartic coupling at two-loop order. These calculations utilized a gauge-invariant parametrization of the trilinear Higgs coupling in terms of higher-dimensional operators $(H^{†}H{)}^n$ with $n\ge 3$. Interestingly, the bounds on ${\kappa }_{\lambda }$ that we obtain are comparable to constraints from di-Higgs production at the LHC as well as recent bounds from single Higgs production at the LHC.

We report on a measurement of the $D^{+}$-meson production cross section as a function of transverse momentum ($p_T$) in proton-antiproton ($p\overline{p}$) collisions at 1.96 TeV center-of-mass energy, using the full data set collected by the Collider Detector at Fermilab in Tevatron Run II and corresponding to $10{\mathrm{fb}}^{-1}$ of integrated luminosity. We use $D^{+}\to K^{-}{\pi }^{+}{\pi }^{+}$ decays fully reconstructed in the central rapidity region $|y|<1$ with transverse momentum down to $1.5\mathrm{GeV}/c$, a range previously unexplored in $p\overline{p}$ collisions. Inelastic $p\overline{p}$-scattering events are selected online using minimally biasing requirements followed by an optimized offline selection. The $K^{-}{\pi }^{+}{\pi }^{+}$ mass distribution is used to identify the $D^{+}$ signal, and the $D^{+}$ transverse impact-parameter distribution is used to separate prompt production, occurring directly in the hard-scattering process, from secondary production from $b$-hadron decays. We obtain a prompt $D^{+}$ signal of 2950 candidates corresponding to a total cross section $\sigma (D^{+},1.5<p_T<14.5\mathrm{GeV}/c,|y|<1)=71.9\pm 6.8(\mathrm{stat})\pm 9.3(\mathrm{syst})\mu \mathrm{b}$. While the measured cross sections are consistent with theoretical estimates in each $p_T$ bin, the shape of the observed $p_T$ spectrum is softer than the expectation from quantum chromodynamics. The results are unique in $p\overline{p}$ collisions and can improve the shape and uncertainties of future predictions.

The processes $e^{+}{e}^{-}\to K_S^0{K}^{\pm }{\pi }^{\mp }{\pi }^0$ and $e^{+}{e}^{-}\to K_S^0{K}^{\pm }{\pi }^{\mp }\eta$ are studied over a continuum of energies from threshold to 4 GeV with the initial-state photon radiation method. Using $454{\text{fb}}^{-1}$ of data collected with the BABAR detector at the SLAC PEP-II storage ring, the first measurements of the cross sections for these processes are obtained. The intermediate resonance structures from $K^{*0}(K\pi {)}^0$, $K^{*}(892{)}^{\pm }(K\pi {)}^{\mp }$, and $K_S^0{K}^{\pm }{\rho }^{\mp }$ are studied. The $J/\psi$ is observed in all of these channels, and corresponding branching fractions are measured.

We consider entanglement through permeable junctions of $N$ ($1+1$)-dimensional free boson and free fermion conformal field theories. In the folded picture we constrain the form of the general boundary state. We calculate replicated partition functions with interface operators inserted in the partially-folded picture, from which the entanglement entropy is calculated. The functional form of the universal and constant terms are the same as the $N=2$ case, depending only of the total transmission of the junction and the unit volume of the zero mode lattice. For $N>2$ we see a subleading divergent term which does not depend on the parameters of the junction. For $N=3$ we consider some specific geometries and discuss various limits.

The Yang-Baxter $\sigma$-model is a systematic way to generate integrable deformations of ${\mathrm{AdS}}_5\times {\mathrm{S}}^5$. We recast the deformations as seen by open strings, where the metric is undeformed ${\mathrm{AdS}}_5\times {\mathrm{S}}^5$ with constant string coupling, and all information about the deformation is encoded in the noncommutative (NC) parameter $\mathrm{\Theta }$. We identify the deformations of ${\mathrm{AdS}}_5$ as twists of the conformal algebra, thus explaining the noncommutativity. We show that the unimodularity condition on $r$-matrices for supergravity solutions translates into $\mathrm{\Theta }$ being divergence-free. Integrability of the $\sigma$-model for unimodular $r$-matrices implies the existence and planar integrability of the dual NC gauge theory.

We investigate how relativistic acceleration of the observers can affect the performance of the quantum teleportation and dense coding for continuous variable states of localized wave packets. Such protocols are typically optimized for symmetric resources prepared in an inertial frame of reference. A mismatch of the sender’s and the receiver’s accelerations can introduce asymmetry to the shared entanglement, which has an effect on the efficiency of the protocol that goes beyond entanglement degradation due to acceleration. We show how these asymmetry losses can be reduced by an extra local operations and classical communication (LOCC) step in the protocols.

We study a vectorial asymptotically free gauge theory, with gauge group $G$ and $N_f$ massless fermions in a representation $R$ of this group, that exhibits an infrared (IR) zero in its beta function, $\beta$, at the coupling $\alpha ={\alpha }_{\mathrm{IR}}$ in the non-Abelian Coulomb phase. For general $G$ and $R$, we calculate the scheme-independent series expansions of (i) the anomalous dimension of the fermion bilinear, ${\gamma }_{\overline{\psi }\psi ,\mathrm{IR}}$, to $O({\mathrm{\Delta }}_f^4)$ and (ii) the derivative ${\beta }^{\prime }=d\beta /d\alpha$, to $O({\mathrm{\Delta }}_f^5)$, both evaluated at ${\alpha }_{\mathrm{IR}}$, where ${\mathrm{\Delta }}_f$ is an $N_f$-dependent expansion variable. These are the highest orders to which these expansions have been calculated. We apply these general results to theories with $G=\mathrm{SU}(N_c)$ and $R$ equal to the fundamental, adjoint, and symmetric and antisymmetric rank-2 tensor representations. It is shown that for all of these representations, ${\gamma }_{\overline{\psi }\psi ,\mathrm{IR}}$, calculated to the order ${\mathrm{\Delta }}_f^p$, with $1\le p\le 4$, increases monotonically with decreasing $N_f$ and, for fixed $N_f$, is a monotonically increasing function of $p$. Comparisons of our scheme-independent calculations of ${\gamma }_{\overline{\psi }\psi ,\mathrm{IR}}$ and ${\beta }_{\mathrm{IR}}^{\prime }$ are made with our earlier higher $n$-loop values of these quantities, and with lattice measurements. For $R=F$, we present results for the limit $N_c\to \infty$ and $N_f\to \infty$ with $N_f/N_c$ fixed. We also present expansions for ${\alpha }_{\mathrm{IR}}$ calculated to $O({\mathrm{\Delta }}_f^4)$.

In a homogeneous and isotropic universe with nonzero spatial curvature we consider the effects of gravitational particle production in the dynamics of the universe. We show that the dynamics of the universe in such a background is characterized by a single nonlinear differential equation which is significantly dependent on the rate of particle creation and whose solutions can be dominated by the curvature effects at early times. For different particle creation rates we apply the singularity test in order to find the analytic solutions of the background dynamics. We describe the behavior of the cosmological solutions for both open and closed universes. We also show how the effects of curvature can be produced by the presence of a second perfect fluid with an appropriate equation of state. By combining that result with the analysis of the critical points we find that our consideration can be related with the preinflationary era. Specifically we find that for negative spatial curvature small changes of the Milne spacetime leads to a de Sitter universe.

We implement an adaptation of the cola approach, a hybrid scheme that combines Lagrangian perturbation theory with an N-body approach, to model nonlinear collapse in chameleon and symmetron modified gravity models. Gravitational screening is modeled effectively through the attachment of a suppression factor to the linearized Klein-Gordon equations. The adapted cola approach is benchmarked, with respect to an N-body code both for the $\mathrm{\Lambda }$ cold dark matter ($\mathrm{\Lambda }\mathrm{CDM}$) scenario and for the modified gravity theories. It is found to perform well in the estimation of the dark matter power spectra, with consistency of 1% to $k\sim 2.5\mathrm{h}/\mathrm{Mpc}$. Redshift space distortions are shown to be effectively modeled through a Lorentzian parametrization with a velocity dispersion fit to the data. We find that cola performs less well in predicting the halo mass functions but has consistency, within $1\sigma$ uncertainties of our simulations, in the relative changes to the mass function induced by the modified gravity models relative to $\mathrm{\Lambda }\mathrm{CDM}$. The results demonstrate that cola, proposed to enable accurate and efficient, nonlinear predictions for $\mathrm{\Lambda }\mathrm{CDM}$, can be effectively applied to a wider set of cosmological scenarios, with intriguing properties, for which clustering behavior needs to be understood for upcoming surveys such as LSST, DESI, Euclid, and WFIRST.

In models of anapole dark matter (DM), the DM candidate is a Majorana fermion whose primary interaction with standard model (SM) particles is through an anapole coupling to off-shell photons. As such, at tree-level, anapole DM undergoes p-wave annihilation into SM charged fermions via a virtual photon. But, generally, Majorana fermions are polarizable, coupling to two real photons. This fact admits the possibility that anapole DM can annihilate into two photons in an s-wave process. Using an explicit model, we compute both the tree-level and diphoton contributions to the anapole DM annihilation cross section. Depending on model parameters, the s-wave process can either rival or be dwarfed by the p-wave contribution to the total annihilation cross section. Subjecting the model to astrophysical upper bounds on the s-wave annihilation mode, we rule out the model with large s-wave annihilation.

We consider the associated production of a scalar resonance with the standard model Higgs boson. We demonstrate via a realistic phenomenological analysis that couplings of such a resonance to the Higgs boson can be constrained in a meaningful way in future runs of the LHC, providing insights on its origin and its relation to the electroweak symmetry breaking sector. Moreover, the final state can provide a direct way to determine whether the new resonance is produced predominantly in gluon fusion or quark-antiquark annihilation. The analysis focuses on a resonance coming from a scalar field with vanishing vacuum expectation value and its decay to a photon pair. It can, however, be straightforwardly generalized to other scenarios.

We study the charmonium spectrum using a complete one gluon exchange approach based on a phenomenological relativistic $q\overline{q}$ potential model with Dirac spinors in momentum space. We use phenomenological screening factors to include vacuum quantum effects. Our formulation does not rely on nonrelativistic approximations. We fit the lowest-lying charmonia (below the $D\overline{D}$ threshold) and predict the higher-lying resonances of the spectrum. In general, we reproduce the overall structure of the charmonium spectrum and, in particular, we can reasonably describe the $X(3872)$ resonance mass as (mostly) a $c\overline{c}$ state. The numerical values of the free parameters of the model are determined taking into account also the experimental uncertainties of the resonance energies. In this way, we are able to obtain the uncertainties of the theoretical resonance masses and the correlation among the free parameters of the model.