The magnetic moments of the low lying, negative parity, spin-$3/2$ baryons, including the ${\mathrm{\Lambda }}^{*}$ baryon, are calculated within the light cone QCD sum rules method. The contributions coming from the positive parity, spin-$3/2$ baryons, as well as from the positive and negative parity spin-$1/2$ baryons are eliminated by constructing combinations of various invariant amplitudes corresponding to the coefficients of the different Lorentz structures. We also present the results for the magnetic moments of the positive parity, spin-$3/2$ baryons.

We study previously introduced models of pseudo–Nambu-Goldstone boson Higgs from linearly realized minimal coset SO(5)/SO(4) and matter in the fundamental in supersymmetric theories. Partial compositeness is at work for top and electroweak gauge fields. New states potentially relevant for LHC signatures are identified and we show how to reinterpret existing experimental results as exclusion bounds. The lightest colored particles, with a mass below the TeV, are fermionic and scalars top partners. We outline a viable mechanism originating masses of other standard model quarks: they result from the generation of dimension five operators in a nonminimal flavor violating context. We study the impact of such operators on flavor processes and we show how experimental bounds are satisfied.

Considering a third-generation squark as the lightest supersymmetric particle (LSP), we investigate R-parity violating collider signatures with bilinear LH or trilinear LQD operators that may contribute to observed neutrino masses and mixings. Reinterpreting various LHC $7+8\mathrm{TeV}$ results of supersymmetry and leptoquark searches, we find that third-generation squark LSPs decaying to first- or second-generation leptons are generally excluded up to at least about 660 GeV at 95% C.L. One notable feature of sbottom LSP models, as opposed to stop LSP models, is that sbottoms can decay to top quarks leading to a broader invariant mass spectrum and weaker constraints in current collider searches. More dedicated searches with $b$-taggings or top reconstructions are thus encouraged. Finally, we discuss that the recently observed excesses in the CMS leptoquark search can be accommodated by decays of mostly left-handed sbottom LSPs in the ${\mathrm{LQD}}_{113+131}$ model.

If $t\to hq$ $(q=c,u)$ or $h\to \tau \ell$ $(\ell =\mu ,e)$ decays are observed, it will be a clear signal of new physics. We investigate whether natural and viable flavor models can saturate the present direct upper bounds without violating the indirect constraints from low energy loop processes. We carry out our analysis in two theoretical frameworks: minimal flavor violation (MFV) and Froggatt-Nielsen symmetry (FN). The simplest models in either framework predict flavor changing couplings that are too small to be directly observed. Yet, in the MFV framework, it is possible to have lepton flavor changing Higgs couplings close to the bound if spurions related to heavy singlet neutrinos play a role. In the FN framework, it is possible to have large flavor changing couplings in both the up and the charged lepton sectors if supersymmetry plays a role.

We consider models of pure gravity mediation in which scalar mass universality is imposed at the grand unified scale and gaugino masses are generated through loops. The minimal model requires a very restricted range for $\tan \beta \approx 2–3$ and scalar masses (set by the gravitino mass) of order 300 TeV–1.5 PeV in order to obtain a Higgs mass near 126 GeV. Here we augment the minimal model with one or more sets of vector multiplets (either a $\mathbf{10}$ and $\overline{\mathbf{10}}$ pair or one or more $\mathbf{5}$ and $\overline{\mathbf{5}}$ pairs). If coupled to the minimal supersymmetric standard model Higgs, these allow for radiative electroweak symmetry breaking over a significantly larger range of $\tan \beta \approx 2–40$ and can fit the Higgs mass with much smaller values of the gravitino mass. In these models, the lightest supersymmetric particle is often the bino, and in order to satisfy the relic density constraint, the bino must be nearly degenerate with either the wino or gluino. In the models considered here, bino gluino coannihilations determine the relic density and since the two are nearly degenerate, LHC limits on the gluino mass are greatly relaxed allowing light relatively gravitinos and gluino masses well within the reach of the LHC.

We consider models of dark matter where the couplings between the standard model and the dark sector fall at resonance due to kinematics and direct detection experiments become insensitive. To be specific, we consider a simple model of 100 GeV–TeV scale dark matter coupled to the standard model via a vector boson. We explore whether it will be possible to exclude such regions of the parameter space using future observations of dijet rates at the LHC and Cherenkov Telescope Array and Alpha Magnetic Spectrometer observations of the Galactic center.

The principle of maximum conformality (PMC) provides a systematic and process-independent method to derive renormalization scheme- and scale-independent fixed-order pQCD predictions. By Brodsky and Wu [Phys. Rev. D 85, 114040 (2012)], we studied the top-quark charge asymmetry at the Tevatron. By applying the PMC, we have shown that the large discrepancies for the top-quark charge asymmetry between the Standard Model estimate and the CDF and D0 data are greatly reduced. In the present paper, with the help of the Bernreuther-Si program, we present a detailed PMC analysis on the top-quark pair production up to next-to-next-to-leading-order level at the LHC. After applying PMC scale setting, the pQCD prediction for the top-quark charge asymmetry at the LHC has very small scale uncertainty; e.g., $A_{\mathrm{C}}{|}_{7\mathrm{TeV};\mathrm{PMC}}=(1.15_{-0.03}^{+0.01})\%$, $A_{\mathrm{C}}{|}_{8\mathrm{TeV};\mathrm{PMC}}=(1.03_{+0.00}^{+0.01})\%$, and $A_{\mathrm{C}}{|}_{14\mathrm{TeV};\mathrm{PMC}}=(0.62_{-0.02}^{+0.00})\%$. The corresponding predictions using conventional scale setting are: $A_{\mathrm{C}}{|}_{7\mathrm{TeV};\text{Conv}}=(1.23_{-0.14}^{+0.14})\%$, $A_{\mathrm{C}}{|}_{8\mathrm{TeV};\text{Conv}}=(1.11_{-0.13}^{+0.17})\%$, and $A_{\mathrm{C}}{|}_{14\mathrm{TeV};\text{Conv}}=(0.67_{-0.05}^{+0.05})\%$. In these predictions, the scale errors are predicted by varying the initial renormalization and factorization scales in the ranges ${\mu }_r^{\text{init}}\in [m_t/2,2m_t]$ and ${\mu }_f\in [m_t/2,2m_t]$. The PMC predictions are also in better agreement with the available ATLAS and CMS data. In addition, we have calculated the top-quark charge asymmetry assuming several typical cuts on the top-pair invariant mass $M_{t\overline{t}}$. For example, assuming $M_{t\overline{t}}>0.5\mathrm{TeV}$ and ${\mu }_f={\mu }_r^{\text{init}}=m_t$, we obtain $A_{\mathrm{C}}{|}_{7\mathrm{TeV};\mathrm{PMC}}=2.67\%$, $A_{\mathrm{C}}{|}_{8\mathrm{TeV};\mathrm{PMC}}=2.39\%$, and $A_{\mathrm{C}}{|}_{14\mathrm{TeV};\mathrm{PMC}}=1.28\%$.

The complete expression of the heavy quark-antiquark potential up to order $1/m^2$ is known from QCD in terms of Wilson loop expectation values. We use that expression and a mapping, assumed to be valid at large distances, between Wilson loop expectation values and correlators evaluated in the effective string theory, to compute the potential. We obtain previously unknown results for the spin- and momentum-independent parts of the potential. These are linearly rising with the distance and may be interpreted as relativistic corrections to the string tension. We confirm known results for the other parts of the potential. Finally, we compute the discrete spectrum of a heavy quark-antiquark pair whose interaction is just given by the obtained potential.

Since the baryon-number susceptibilities are correlated with the cumulant of baryon-number fluctuations in experiments, we do calculations of the susceptibilities and compare them with the experimental fluctuation data under the framework of the Dyson-Schwinger equations (DSEs) approach. We compare our results with lattice QCD and experimental data at RHIC. The fitness of the results indicates that under the framework of DSEs, we can deal with the problems of heavy ion collisions properly.

The radiative decay of sterile neutrinos with typical masses of 10 keV is investigated in the presence of a strong magnetic field and degenerate plasma. A full account is taken of the strongly modified photon dispersion relation relative to vacuum. The limiting cases of relativistic and nonrelativistic plasma are analyzed. The decay rate in a strongly magnetized plasma as a function of the electron number density is compared with the unmagnetized case. We find that a strong magnetic field suppresses the catalyzing influence of the plasma on the decay rate.

Tests of Lorentz and $CPT$ violation in the medium baseline reactor antineutrino experiment are presented in the framework of the standard model extension. Both the spectral distortion and sidereal variation are employed to derive the limits of Lorentz violation coefficients. We do the numerical analysis of the sensitivity of LV coefficients by taking the Jiangmen Underground Neutrino Observatory (JUNO) as an illustration, which can improve the sensitivity by more than two orders of magnitude compared with the current limits from reactor antineutrino experiments.

Dwarf spheroidal galaxies of the Local Group are close satellites of the Milky Way characterized by a large mass-to-light ratio and are not expected to be the site of nonthermal high-energy gamma-ray emission or intense star formation. Therefore they are among the most promising candidates for indirect dark matter searches. During the last years the High Energy Stereoscopic System (H.E.S.S.) of imaging atmospheric Cherenkov telescopes observed five of these dwarf galaxies for more than 140 hours in total, searching for TeV gamma-ray emission from annihilation of dark matter particles. The new results of the deep exposure of the Sagittarius dwarf spheroidal galaxy, the first observations of the Coma Berenices and Fornax dwarves and the reanalysis of two more dwarf spheroidal galaxies already published by the H.E.S.S. Collaboration, Carina and Sculptor, are presented. In the absence of a significant signal new constraints on the annihilation cross section applicable to weakly interacting massive particles (WIMPs) are derived by combining the observations of the five dwarf galaxies. The combined exclusion limit depends on the WIMP mass and the best constraint is reached at 1–2 TeV masses with a cross-section upper bound of $\sim 3.9\times {10}^{-24}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$ at a 95% confidence level.

We study the Abelian projection of quark confinement in SU(3) quenched lattice QCD, in terms of the dual superconductor picture. In the maximal Abelian gauge, we perform the Cartan decomposition of the non-Abelian gauge field on a $32^4$ lattice with spacing $a\simeq 0.058$, 0.10 fm (i.e., $\beta =6.4$, 6.0), and investigate the interquark potential $V(r)$, the Abelian part $V_{\text{Abel}}(r)$, and the off-diagonal part $V_{\text{off}}(r)$. For the potential analysis, we use both on-axis data and several types of off-axis data, with larger numbers of gauge configurations. Remarkably, we find almost perfect Abelian dominance of the string tension (quark-confining force) on the large-volume lattice. Also, we find a simple but nontrivial relation of $V(r)\simeq V_{\text{Abel}}(r)+V_{\text{off}}(r)$.

We study glueballs in the holographic gauge theories living in a curved space-time. The dual bulk is obtained as a solution of the type IIB superstring theory with two parameters, which correspond to the four-dimensional cosmological constant $\lambda$ and the dark radiation $C$, respectively. The theory is in the confining phase for $\lambda <0$ and small $C$, then we observe stable glueball states in this theory. However, the stability of the glueball states is lost when the density of the dark radiation ($C$) increases and exceeds a critical point. Above this point, the dark radiation works as the heat bath of the Yang-Mills theory since the event horizon appears. Thus the system is thermalized, and the theory is in a finite temperature deconfinement phase, namely in the QGP phase. We observe this transition process through the glueball spectra which varies dramatically with $C$. We also examined the entanglement entropy of the system to find a clue of this phase transition and the role of the dark radiation $C$ in the entanglement entropy.

We study the quantum dynamics of a suddenly released beam of particles using a background independent (polymer) quantization scheme. We show that, in the first order of approximation, the low-energy polymer distribution converges to the standard quantum-mechanical result in a clear fashion, but also arises an additional small polymer correction term. We find that the high-energy polymer behavior becomes predominant at short distances and short times, as we should expect. Numerical results are also presented. We find that particles whose wave functions satisfy the polymer wave equation do not exhibit the diffraction in time phenomena. The implementation of a modified time-energy uncertainty relation in the polymer framework is briefly discussed.

We report on a mean-field study of spontaneous breaking of chiral symmetry for Dirac fermions with contact interactions in the presence of chiral imbalance, which is modeled by nonzero chiral chemical potential. We point out that chiral imbalance lowers the vacuum energy of Dirac fermions, which leads to the increase of the renormalized chiral chemical potential upon chiral symmetry breaking. The critical coupling strength for the transition to the broken phase is slightly lowered as the chiral chemical potential is increased, and the transition itself becomes milder. Furthermore, we study the chiral magnetic conductivity in different phases and find that it grows both in the perturbative weak-coupling regime and in the strongly coupled phase with broken chiral symmetry. In the strong coupling regime the chiral magnetic effect is saturated by vectorlike bound states (vector mesons) with mixed transverse polarizations. General pattern of meson mixing in the presence of chiral imbalance is also considered. We discuss the relevance of our study for Weyl semimetals and strongly interacting QCD matter. Finally, we comment on the ambiguity of the regularization of the vacuum energy of Dirac fermions in the presence of chirality imbalance.

The Stückelberg analysis of nonlinear massive gravity in the presence of a general fiducial metric is investigated. We develop a “covariant” formalism for the Stückelberg expansion by working with a local inertial frame, through which helicity modes can be characterized correctly. Within this covariant approach, an extended ${\mathrm{\Lambda }}_3$ decoupling limit analysis can be consistently performed, which keeps ${\overline{R}}_{\mu \nu \rho \sigma }/m^2$ fixed with ${\overline{R}}_{\mu \nu \rho \sigma }$ the Riemann tensor of the fiducial metric. In this extended decoupling limit, the scalar mode $\pi$ acquires self-interactions due to the presence of the curvature of the fiducial metric. However, the equation of motion for $\pi$ remains of second order in derivatives, which extends the understanding of the absence of the Boulware Deser ghost in the case of a flat fiducial metric.

We consider three-dimensional gravity with negative cosmological constant in the presence of a scalar and an Abelian gauge field. Both fields are conformally coupled to gravity, the scalar field through a nonminimal coupling with the curvature and the gauge field by means of a Lagrangian given by a power of the Maxwell one. A sixth-power self-interaction potential, which does not spoil conformal invariance is also included in the action. Using a circularly symmetric ansatz, we obtain black hole solutions dressed with the scalar and gauge fields, which are regular on and outside the event horizon. These charged hairy black holes are asymptotically anti–de Sitter spacetimes. The mass and the electric charge are computed by using the Regge-Teitelboim Hamiltonian approach. If both leading and subleading terms of the asymptotic condition of the scalar field are present, a boundary condition that functionally relates them is required for determining the mass. Since the asymptotic form of the scalar field solution is defined by two integration constants, the boundary condition may or may not respect the asymptotic conformal symmetry. An analysis of the temperature and entropy of these black holes is presented. The temperature is a monotonically increasing function of the horizon radius as expected for asymptotically anti–de Sitter black holes. However, restrictions on the parameters describing the black holes are found by requiring the entropy to be positive, which, given the nonminimal coupling considered here, does not follow the area law. Remarkably, the same conditions ensure that the conformally related solutions become black holes in the Einstein frame.

In this work we aim at discussing the effects of the higher order curvature terms on the Lovelock AdS black holes quasinormal spectrum and, in the context of gauge/gravity correspondence, their consequences for the formation of holographic superconductors. We also explore the hydrodynamic limit of the $U(1)$ gauge field perturbations in $d$ dimensions.