We analyze the expectation value of the Polyakov loop in the fundamental and higher representations in the confined phase of QCD. We discuss a hadroniclike representation and find that the Polyakov loop corresponds to a partition function in the presence of a colored source, explaining its real and positive character. Saturating the sum rules to intermediate temperatures requires a large number of multipartonic excited states. By using constituent or bag models, we find detailed low temperature scaling rules which depart from the Casimir scaling and could be tested by lattice calculations.

Cosmic-ray antinuclei provide a promising discovery channel for the indirect detection of particle dark matter. Hadron showers produced by the pair annihilation or decay of Galactic dark matter generate antinucleons which can in turn form light antinuclei. Previous studies have only focused on the spectrum and flux of low energy antideuterons which, although very rarely, are occasionally also produced by cosmic-ray spallation. Heavier elements ($A\ge 3$) have instead entirely negligible astrophysical background and a primary yield from dark matter which could be detectable by future experiments. Using a Monte Carlo event generator and an event-by-event phase space analysis, we compute, for the first time, the production spectrum of ${}^3\overline{\mathrm{He}}$ and ${}^3\overline{\mathrm{H}}$ for dark matter annihilating or decaying to $b\overline{b}$ and $W^{+}{W}^{-}$ final states. We then employ a semianalytic model of interstellar and heliospheric propagation to calculate the ${}^3\overline{\mathrm{He}}$ flux as well as to provide tools to relate the antihelium spectrum corresponding to an arbitrary antideuteron spectrum. Finally, we discuss prospects for current and future experiments, including GAPS and AMS-02.

We correct a number of earlier calculations of the loop contribution of a dimension-6, $CP$-violating operator involving $W^{+}{W}^{-}\gamma$ to the neutron electric dipole moment, showing that measurements imply a very strong bound on the operator. We also quantify the link between this operator and a companion operator involving $W^{+}{W}^{-}Z$, which has been suggested as a target for new physics searches at the Large Hadron Collider, showing that even strongly coupled new physics could only be observable in the proposed searches if it appeared at a scale below $\sim 170\mathrm{GeV}$.

In this paper we study the diffractive $Z$ boson pair production mediated by the Kaluza-Klein graviton in the large extra dimensions scenario at the CERN Large Hadron Collider energies. Considering the Durham model, we estimate the total cross section for the central inclusive and exclusive diffractive production of a $Z$ boson pair in $pp/pPb/PbPb$ collisions. Our results indicate that the experimental analysis of the central inclusive production in $pp$ collisions is feasible at the CERN LHC.

We present the precision predictions on the pair production of light, $CP$-even Higgs boson in weak vector boson fusion (VBF) up to the QCD next-to-next-to-leading order (NNLO) at hadron colliders within the $CP$-conserving type II two-Higgs-doublet model [2HDM(II)] by adopting the structure function approach. We investigate the model parameter dependence, residual uncertainties from the factorization/renormalization scale, PDFs, and ${\alpha }_s$ on the integrated cross section at the QCD NNLO and find that the NNLO QCD corrections can reduce the scale uncertainty significantly. By analyzing the kinematic distributions of final Higgs bosons, we can extract the $CP$-even Higgs resonance via the $H^0\to h^0{h}^0$ channel as a means of probing the extension of the standard model (SM) Higgs sector.

In addition to gravity, there might be another very weak interaction between the ordinary and dark matter transmitted by $U^{\prime }(1)$ gauge bosons $A^{\prime }$ (dark photons) mixing with our photons. If such $A^{\prime }$’s exist, they could be searched for in a light-shining-through-a-wall experiment with a high-energy electron beam. The electron energy absorption in a calorimeter (CAL1) is accompanied by the emission of bremsstrahlung $A^{\prime }$’s in the reaction $eZ\to eZ{A}^{\prime }$ of electrons scattering on nuclei due to the $\gamma -A^{\prime }$ mixing. A part of the primary beam energy is deposited in the CAL1, while the rest of the energy is transmitted by the $A^{\prime }$ through the “CAL1 wall” and deposited in another downstream calorimeter CAL2 by the $e^{+}{e}^{-}$ pair from the $A^{\prime }\to e^{+}{e}^{-}$ decay in flight. Thus, the $A^{\prime }$’s could be observed by looking for an excess of events with the two-shower signature generated by a single high-energy electron in the CAL1 and CAL2. A proposal to perform such an experiment to probe the still unexplored area of the mixing strength ${10}^{-5}\lesssim \epsilon \lesssim {10}^{-3}$ and masses $M_{A^{\prime }}\lesssim 100\mathrm{MeV}$ by using 10–300 GeV electron beams from the CERN SPS is presented. The experiment can provide complementary coverage of the parameter space, which is intended to be probed by other searches. It has also a capability for a sensitive search for $A^{\prime }$’s decaying invisibly to dark-sector particles, such as dark matter, which could cover a significant part of the still allowed parameter space.

We explore the coannihilation region of the constrained minimal supersymmetric standard model (CMSSM) being consistent with current experimental/observational results. The requirements from the experimental/observational results are the 125 GeV Higgs boson mass and the relic abundances of both the dark matter and light elements, especially lithium-7. We put these requirements on the calculated values, and, thus, we obtain the allowed region. Then we give predictions to the mass spectra of the supersymmetric (SUSY) particles, the anomalous magnetic moment of the muon, the branching fractions of the $B$-meson rare decays, the direct detection of the neutralino dark matter, and the number of SUSY particles produced in a 14 TeV run at the LHC experiment. Comparing these predictions with current bounds, we show the feasibility of the test for this scenario in near future experiments.

The quantization condition for two-particle systems with an arbitrary number of two-body open coupled channels, spin, momentum, and masses in a finite volume with either periodic or twisted boundary conditions is presented. Although emphasis is placed in cubic volumes, the result holds for asymmetric volumes. The result is relativistic, holds for all momenta below the three- and four-particle thresholds, and is exact up to exponential volume corrections that are governed by $L/r$, where $L$ is the spatial extent of the volume and $r$ is the range of the interactions between the particles. For hadronic systems the range of the interaction is set by the inverse of the pion mass, $m_{\pi }$, and as a result the formalism presented is suitable for $m_{\pi }L\gg 1$. The condition presented is in agreement with all previous studies of two-body systems in a finite volume. Implications of the formalism for the studies of multichannel baryon-baryon systems are discussed.

We present a valence calculation of the electric polarizability of the neutron, neutral pion, and neutral kaon on two dynamically generated nHYP-clover ensembles. The pion masses for these ensembles are 227(2) MeV and 306(1) MeV, which are the lowest ones used in polarizability studies. This is part of a program geared toward determining these parameters at the physical point. We carry out a high statistics calculation that allows us to: (i) perform an extrapolation of the kaon polarizability to the physical point; we find ${\alpha }_K=0.269(43)\times 10^{-4}{\mathrm{fm}}^3$, (ii) quantitatively compare our neutron polarizability results with predictions from $\chi \mathrm{PT}$, and (iii) analyze the dependence on both the valence and sea quark masses. The kaon polarizability varies slowly with the light quark mass and the extrapolation can be done with high confidence.

It has been argued that the leading scalar-isoscalar weakly interacting massive particle (WIMP) -nucleus interactions receive parametrically enhanced contributions in the context of nuclear effective field theories [1]. These contributions arise from meson-exchange currents (MECs) and potentially modify the impulse approximation estimates of these interactions by 10%–60%. We point out that these MECs also contribute to the quark mass dependence of nuclear binding energies, that is, nuclear $\sigma$ terms. In this work, we use recent lattice QCD calculations of the binding energies of the deuteron, ${}^3\mathrm{He}$ and ${}^4\mathrm{He}$ at pion masses near 500 and 800 MeV, combined with the experimentally determined binding energies at the physical point, to provide approximate determinations of the $\sigma$ terms for these light nuclei. For each nucleus, we find that the deviation of the corresponding nuclear $\sigma$ term from the single-nucleon estimate is at the few-percent level, in conflict with the conjectured enhancement. As a consequence, lattice QCD calculations currently indicate that the cross sections for scalar-isoscalar WIMP-nucleus interactions arising from fundamental WIMP interactions with quarks do not suffer from significant uncertainties due to enhanced MECs.

We present results for the kaon mixing parameter $B_K$ obtained using improved staggered fermions on a much enlarged set of MILC asqtad lattices. Compared to our previous publication, which was based largely on a single ensemble at each of the three lattice spacings $a\approx 0.09\mathrm{fm}$, 0.06 fm and 0.045 fm, we have added seven new fine and four new superfine ensembles, with a range of values of the light and strange sea-quark masses. We have also increased the number of measurements on one of the original ensembles. This allows us to do controlled extrapolations in the light and strange sea-quark masses, which we do simultaneously with the continuum extrapolation. This reduces the extrapolation error and improves the reliability of our error estimates. Our final result is ${\widehat{B}}_K=0.7379\pm 0.0047(\text{stat})\pm 0.0365(\mathrm{sys})$.

We carry out the first complete calculation of kinematic power corrections $\sim t/Q^2$ and $\sim m^2/Q^2$ to several key observables in deeply virtual Compton scattering. The issue of convention dependence of the leading twist approximation is discussed in detail. In addition, we work out representations for the higher twist corrections in terms of double distributions, Mellin-Barnes integrals and also within a dissipative framework. This study removes an important source of uncertainties in the QCD predictions for intermediate photon virtualities $Q^2\sim 1–5{\mathrm{GeV}}^2$ that are accessible in the existing and planned experiments. In particular the finite-$t$ corrections are significant and must be taken into account in the data analysis.

We use QCD light-cone sum rules with holographic anti–de Sitter/Chromodynamics (AdS/QCD) distribution amplitudes for the $K^{*}$ meson in order to predict the full set of seven $B\to K^{*}$ transition form factors for intermediate-to-high recoil of the vector meson. We provide simple parametrizations for the form factors that fit our AdS/QCD predictions. We also provide parametrizations that fit both our AdS/QCD predictions and the most recent lattice data for low recoil. We use our form factors to predict the differential and total branching fraction of the rare dileptonic decay, $B\to K^{*}{\mu }^{+}{\mu }^{-}$, which we compare to the recent LHCb data.

In the paper, we present a detailed discussion on the ${\mathrm{\Xi }}_{cc}$ production at a fixed-target experiment at the LHC (After@LHC). The doubly charmed baryon ${\mathrm{\Xi }}_{cc}$ is produced via the channel $\text{proton}+\text{proton}\to {\mathrm{\Xi }}_{cc}+X$. In estimating its hadroproduction, we discuss three dominant subprocesses, e.g., $g+g\to {\mathrm{\Xi }}_{cc}+\overline{c}+\overline{c}$, $g+c\to {\mathrm{\Xi }}_{cc}+\overline{c}$, and $c+c\to {\mathrm{\Xi }}_{cc}+g$. During the production, it will first generate a binding diquark and then form the ${\mathrm{\Xi }}_{cc}$ baryon by grabbing soft light quarks or gluons. We observe that both the two diquark configurations $(cc)[{}^3{S}_1{]}_{\overline{\mathbf{3}}}$ and $(cc)[{}^1{S}_0{]}_{\mathbf{6}}$ can have sizable contributions to the ${\mathrm{\Xi }}_{cc}$ production. A large number of ${\mathrm{\Xi }}_{cc}$ events can be generated at the After@LHC, whose total production cross section is larger than that of the SELEX experiment by about 35 times. It may also be possible to study the properties of ${\mathrm{\Xi }}_{bc}$ at the After@LHC. More specifically, we will have about $8.3\times {10}^6{\mathrm{\Xi }}_{cc}\text{events}/\text{year}$ and $1.8\times {10}^4{\mathrm{\Xi }}_{bc}\text{events}/\text{year}$ when its integrated luminosity approaches $2{\mathrm{fb}}^{-1}/\text{year}$. Thus, in addition to SELEX and LHC, the After@LHC will provide another useful platform for studying the baryon properties.

We investigate the neutron’s response to magnetic fields on a torus with the aid of chiral perturbation theory, and expose effects from nonvanishing holonomies. The determination of such effects necessitates nonperturbative treatment of the magnetic field; and, to this end, a strong-field power counting is employed. Using a novel coordinate-space method, we find the neutron propagates in a coordinate-dependent effective potential that we obtain by integrating out charged pions winding around the torus. Knowledge of these finite volume effects will aid in the extraction of neutron properties from lattice QCD computations in external magnetic fields. In particular, we obtain finite volume corrections to the neutron magnetic moment and magnetic polarizability. These quantities have not been computed correctly in the literature. In addition to effects from nonvanishing holonomies, finite volume corrections depend on the magnetic flux quantum through an Aharonov-Bohm effect. We make a number of observations that demonstrate the importance of nonperturbative effects from strong magnetic fields currently employed in lattice QCD calculations. These observations concern neutron physics in both finite and infinite volume.

We discuss the characteristics of collective modes induced by relativistic jets in a collisionless anisotropic quark-gluon plasma (AQGP) assuming a colorless Tsunami-like momentum distribution of the jet partons. Within the framework of the transport equation, we derive and discuss the dispersion relations for both the stable and unstable modes of the composite system in the Vlasov approximation. We consider the case when the wave vector is parallel to the anisotropy direction as the growth rate of the unstable mode is maximum in this scenario. When the wave vector ($\mathbf{k}$) is perpendicular to the jet velocity (${\mathbf{v}}_{\text{jet}}$), two stable modes are found (referred to as mode I and mode II hereafter) of which one is independent of the jet velocity. In case of $\mathbf{k}\parallel {\mathbf{v}}_{\text{jet}}$, we obtain two identical modes (mode I) and one distinct mode (referred to as mode III hereafter). In all of the cases it is found that stable modes shift toward the light cone for nonzero values of the anisotropy parameter ($\xi$) and the jet strength ($\eta$). In case of unstable mode I, the growth rate increases with $\xi$ for fixed $\eta$. The growth rate in case of modes II and III increases with $\xi$ and $\eta$, and the nature of the increase depends on the jet velocity.

I compute the contributions of the one-loop single-real-emission amplitudes, $gg\to Hg$, $qg\to Hq$, etc., to inclusive Higgs boson production through next-to-next-to-next-to-leading order (${\mathrm{N}}^3\mathrm{LO}$) in the strong coupling ${\alpha }_s$. The next-to-leading and next-to-next-to-leading order terms are computed in closed form, in terms of $\mathrm{\Gamma }$ functions and the hypergeometric functions ${}_2{F}_1$ and ${}_3{F}_2$. I compute the ${\mathrm{N}}^3\mathrm{LO}$ terms as Laurent expansions in the dimensional regularization parameter through order $({ϵ}^1)$. To obtain the ${\mathrm{N}}^3\mathrm{LO}$ terms, I perform an extended threshold expansion of the phase space integrals and map the resulting coefficients onto a basis of harmonic polylogarithms.

The monoenergetic 236 MeV muon neutrino from charged kaon decay at rest ($K^{+}\to {\mu }^{+}{\nu }_{\mu }$) can be used to produce a novel set of cross section measurements. Applicable for short- and long-baseline accelerator-based neutrino oscillation experiments, among others, such measurements would provide a “standard candle” for the energy reconstruction and interaction kinematics relevant for charged current neutrino events near this energy. This neutrino can also be exercised as a unique known-energy, purely weak interacting probe of the nucleus. A number of experiments are set to come online in the next few years that will be able to collect and characterize thousands of these events.

We study the advantages of a second identical detector at a medium baseline reactor neutrino experiment. A major obstruction to the determination of the neutrino mass hierarchy is the detector’s unknown nonlinear energy response, which even under optimistic assumptions reduces the sensitivity to the hierarchy by about $1\sigma$ at a single detector experiment. Various energy response models are considered at one- and two-detector experiments with the same total target mass. A second detector at a sufficiently different baseline eliminates this $1\sigma$ reduction. Considering the unknown energy response, we find the sensitivity to the hierarchy at various candidate detector locations for JUNO and RENO 50. The best site for JUNO’s near detector is under ZiLuoShan, 17 and 66 km from the Yangjiang and Taishan reactor complexes, respectively. We briefly describe other advantages, including a more precise determination of ${\theta }_{12}$ and the possibility of a $\mathrm{DAE}\delta \mathrm{ALUS}$-inspired program to measure the $CP$-violating phase $\delta$ using a single pion source about 10 km from one detector and 20 km from the other. Two identical half-sized detectors provide a better energy resolution than a single detector, further increasing the sensitivity to the hierarchy.

We study the possibility of intrinsic (nonperturbative) charm in parton distribution functions (PDF) of the proton, within the context of the CT10 next-to-next-to-leading order global analysis. Three models for the intrinsic charm (IC) quark content are compared: (i) $\widehat{c}(x)=0$ (zero-IC model); (ii) $\widehat{c}(x)$ is parametrized by a valence-like parton distribution (BHPS model); (iii) $\widehat{c}(x)$ is parametrized by a sea-like parton distribution (SEA model). In these models, the intrinsic charm content, $\widehat{c}(x)$, is included in the charm PDF at the matching scale $Q_c=m_c=1.3\mathrm{GeV}$. The best fits to data are constructed and compared. Correlations between the value of $m_c$ and the amount of IC are also considered.