Higgs inflation is attractive because it identifies inflaton with the electroweak Higgs boson. In this work, we construct a new class of supersymmetric Higgs inflationary models in no-scale supergravity with an SU(5) grand unified theory (GUT) group. Extending the no-scale Kähler potential and SU(5) GUT superpotential, we derive a generic potential for Higgs inflation that includes the quadratic monomial potential and a Starobinsky-type potential as special limits. This type of models can accommodate a wide range of the tensor-to-scalar ratio $r=\mathcal{O}({10}^{-3}-{10}^{-1})$ as well as a scalar spectral index $n_s\sim 0.96$.

In this work, we study weak transitions of ${\mathrm{\Lambda }}_b$ to light baryons $\mathrm{\Lambda }$ and $p$ in the Bethe-Salpeter equation approach. In the heavy quark limit, based on the picture that ${\mathrm{\Lambda }}_b$ is composed of a heavy $b$-quark and a light diquark, the Bethe-Salpeter equation for ${\mathrm{\Lambda }}_b$ was established in previous works. Although the light baryon $\mathrm{\Lambda }(p)$ is composed of various quark-diquark configurations based on the $SU(6)$ spin-flavor wave functions, only the configuration $s(ud{)}_{0,0}$ [$u(ud{)}_{0,0}$] [$(ud{)}_{0,0}$ is a scalar diquark composed of $u$ and $d$ quarks] contributes to ${\mathrm{\Lambda }}_b\to \mathrm{\Lambda }$ (${\mathrm{\Lambda }}_b\to p$) transition. We establish the Bethe-Salpeter equations for the systems $s(ud{)}_{0,0}$ and $u(ud{)}_{0,0}$ and calculate their Bethe-Salpeter wave functions in the covariant instantaneous approximation with the kernel containing both scalar confinement and one-gluon-exchange terms. Then, the form factors for ${\mathrm{\Lambda }}_b\to \mathrm{\Lambda }$ and ${\mathrm{\Lambda }}_b\to p$ weak transitions are obtained with Bethe-Salpeter wave functions for ${\mathrm{\Lambda }}_b$, $\mathrm{\Lambda }$, and $p$. Consequently, we calculate the branching ratios of ${\mathrm{\Lambda }}_b\to \mathrm{\Lambda }P$, ${\mathrm{\Lambda }}_b\to \mathrm{\Lambda }V$, $\mathrm{\Lambda }\to pP$, and ${\mathrm{\Lambda }}_b\to pV$ ($P$ and $V$ denote pseudoscalar and vector mesons, respectively) in the factorization approach.

We propose an experiment to search for ultralight scalar dark matter (DM) with dilatonic interactions. Such couplings can arise for the dilaton as well as for moduli and axion-like particles in the presence of $CP$ violation. Ultralight dilaton DM acts as a background field that can cause tiny but coherent oscillations in Standard Model parameters such as the fine-structure constant and the proton-electron mass ratio. These minute variations can be detected through precise frequency comparisons of atomic clocks. Our experiment extends current searches for drifts in fundamental constants to the well-motivated high-frequency regime. Our proposed setups can probe scalars lighter than $10^{-15}\mathrm{eV}$ with a discovery potential of dilatonic couplings as weak as $10^{-11}$ times the strength of gravity, improving current equivalence principle bounds by up to 8 orders of magnitude. We point out potential $10^4$ sensitivity enhancements with future optical and nuclear clocks, as well as possible signatures in gravitational-wave detectors. Finally, we discuss cosmological constraints and astrophysical hints of ultralight scalar DM, and show they are complimentary to and compatible with the parameter range accessible to our proposed laboratory experiments.

The presence of the anomalous top-quark flavor-changing neutral-current (FCNC) interactions leads to the production of same-sign top quarks in proton-proton collisions. The results of a search for events with same-sign dileptons and $b$ jets conducted by the CMS Collaboration with $10.5{\mathrm{fb}}^{-1}$ of data collected in $pp$ collisions at $\sqrt{s}=8\mathrm{TeV}$ are used to obtain the constraints on the strength of top-quark FCNC interactions. The 95% confidence level upper limits on the branching ratios of top-quark decays to a light quark $q=u,c$ and a gauge or a Higgs boson are set to be $\text{BR}(t\to u\gamma )<1.27\%$, $\text{BR}(t\to uZ)<0.8\%$, $\text{BR}(t\to ug)<1.02\%$, and $\text{BR}(t\to uH)<4.21\%$. The sensitivity of future searches in the same-sign top-quark channel is also presented.

We propose a four-quark structure for some of the excited states of heavy mesons containing a single charm or bottom quark. The four-quark wave functions are constructed based on a diquark-antidiquark form under the constraint that they form an antitriplet ${\overline{\mathbf{3}}}_f$ in ${\mathrm{SU}(3)}_f$, which seems to be realized in some of the excited states listed by the Particle Data Group. Depending on the structure of the antidiquark, we construct two possible models for its wave functions: Model I, where the antidiquark is symmetric in flavor (${\overline{\mathbf{6}}}_f$) and antisymmetric in color (${\mathbf{3}}_c$), and Model II, where the antidiquark is antisymmetric in flavor (${\mathbf{3}}_f$) and symmetric in color (${\overline{\mathbf{6}}}_c$). To test the phenomenological relevance of these wave functions, we calculate the mass differences among the excited states of spin $J=0$, 1, 2 using color-spin interactions. The four-quark wave functions based on Model I are found to reproduce the observed mass of the excited states of heavy mesons. Also, our four-quark model provides an interesting phenomenology related to the decay widths of the excited states. To further pursue the possibility of the four-quark structure, we make a few predictions for open-charm and open-bottom states that may be discovered in future experiments. Most of these are expected to have broad widths, which would make them difficult to be identified experimentally. However, one resonance with $J=1$ containing bottom and strange quarks is expected to appear as a sharp peak with a mass around $B_{1N}^{\overline{s}}\sim 5753\mathrm{MeV}$. The confirmation of the existence of such states in future experiments will shed light on our understanding of the structure of heavy meson excited states.

To explain the fermion masses and mixings naturally, we introduce a specific flavor symmetry and mass suppression pattern that constrain the flavor structure of the fermion Yukawa couplings. Our model describes why the hierarchy of neutrino masses is milder than the hierarchy of charged fermion masses in terms of successive powers of flavon fields. We investigate $CP$ violation and neutrinoless double beta ($0\nu \beta \beta$) decay and show how they can be predicted and constrained in our model by present and upcoming experimental data. Our model predicts that the atmospheric neutrino mixing angle ${\theta }_{23}$ should be within $\sim 1°$ of 45° for the normal neutrino mass ordering and between $\sim 4°$ and $\sim 8°$ degrees away from 45° (in either direction) for the inverted neutrino mass ordering. For both neutrino mass ordering and inverted neutrino mass ordering, our model predicts that a $0\nu \beta \beta$ Majorana mass in the limited range $0.035\mathrm{eV}<|m_{ee}|\lesssim 0.15\mathrm{eV}$, which can be tested in current experiments. Moreover, our model can successfully accommodate flavorless leptogenesis as the mechanism to generate the baryon asymmetry in the Universe, provided the neutrino mass ordering is normal, $|m_{ee}|\simeq 0.072\pm 0.012\mathrm{eV}$, and either ${\theta }_{23}\simeq 44°$ and the Dirac $CP$-violating phase ${\delta }_{CP}\simeq 20°$ or 60° or ${\theta }_{23}\simeq 46°$ and ${\delta }_{CP}\simeq 205°$ or 245°.

Axions are well motivated particles that could make up most or all of the dark matter if they have masses below $100\mu \mathrm{eV}$. Microwave cavity techniques comprised of closed resonant structures immersed in solenoid magnets are sensitive to dark matter axions with masses of a few $\mu \mathrm{eV}$ but face difficulties scaling to higher masses. We present the a novel detector architecture consisting of an open, Fabry–Pérot resonator and a series of current-carrying wire planes and demonstrate this technique with a search for dark matter axionlike particles called Orpheus. This search excludes dark matter axionlike particles with masses between 68.2 and $76.5\mu \mathrm{eV}$ and axion-photon couplings greater than $4\times 10^{-7}{\mathrm{GeV}}^{-1}$. We project that the fundamental sensitivity of this technique could be extended to be sensitive to couplings below $1\times 10^{-15}{\mathrm{GeV}}^{-1}$, consistent with the DFSZ model of QCD axions.

We correct certain numerical estimates made in our paper. This correction, however, does not alter the conclusion that when Lorentz forces are taken into account, the supermassive white dwarf models, obtained simply by modifying the equation of state in presence of a superstrong magnetic field in the center, fail to be in equilibrium.

We show that the upper bound for the central magnetic field of a super-Chandrasekhar white dwarf calculated by Nityananda and Konar [Phys. Rev. D 89, 103017 (2014)] and in the concerned comment, by the same authors, against our work [U. Das and B. Mukhopadhyay, Phys. Rev. D 86, 042001 (2012)] is erroneous. This in turn strengthens the argument in favor of the stability of the recently proposed magnetized super-Chandrasekhar white dwarfs. We also point out several other numerical errors in their work. Overall we conclude that the arguments put forth by Nityananda and Konar are misleading.

The supermassive white dwarf models proposed by Das and Mukhopadhyaya [Phys. Rev. D 86, 042001 (2012)], based on modifying the equation of state by a superstrong magnetic field in the center, are very far from equilibrium because of the neglect of Lorentz forces, as has recently been shown by Nityananda and Konar [Phys. Rev. D 89, 103017 (2014].

We generalize the ordinary Wess-Zumino model to the bosonic-fermionic noncommutative (BFNC) superspace and study its renormalization. In our previous work that can be regarded as the key foundation of the present paper, we have proved that the BFNC Wess-Zumino model with the real mass and interacting constant is one-loop renormalizable up to the second order of BFNC parameters. Based on the result obtained, in the present paper we modify the one-loop renormalizable BFNC Wess-Zumino model by generalizing the mass and interacting constant to complex numbers, introduce the $U(1{)}_{\mathrm{R}}$ $R$ symmetry and $U(1{)}_{\mathrm{\Phi }}$ flavor symmetry in the modified model, analyze possible divergent operators in the effective action of the modified model by using the dimensional analysis method, and further give a new BFNC Wess-Zumino model that is renormalizable at all loops still up to the second order of BFNC parameters by imposing symmetries rather than doing a direct perturbative investigation.

Minimal massive gravity (MMG) is an extension of three-dimensional topologically massive gravity that, when formulated about anti-de Sitter space, accomplishes solving the tension between bulk and boundary unitarity that other models in three dimensions suffer from. We study this theory at the chiral point, i.e. at the point of the parameter space where one of the central charges of the dual conformal field theory vanishes. We investigate the nonlinear regime of the theory, meaning that we study exact solutions to the MMG field equations that are not Einstein manifolds. We exhibit a large class of solutions of this type, which behave asymptotically in different manners. In particular, we find analytic solutions that represent two-parameter deformations of extremal Bañados–Teitelboim–Zanelli black holes. These geometries behave asymptotically as solutions of the so-called log gravity, and, despite the weakened falling off close to the boundary, they have finite mass and finite angular momentum, which we compute. We also find time-dependent deformations of Bañados–Teitelboim–Zanelli that obey Brown–Henneaux asymptotic boundary conditions. The existence of such solutions shows that the Birkhoff theorem does not hold in MMG at the chiral point. Other peculiar features of the theory at the chiral point, such as the degeneracy it exhibits in the decoupling limit, are discussed.

Direct detection (DD) of dark matter (DM) candidates in the $\lesssim 10\mathrm{GeV}$ mass range is very sensitive to the tail of their velocity distribution. The important quantity is the maximum weakly interacting massive particle speed in the observer’s rest frame, i.e. in average the sum of the local Galactic escape speed $v_{\text{esc}}$ and of the circular velocity of the Sun $v_c$. While the latter has been receiving continuous attention, the former is more difficult to constrain. The RAVE Collaboration has just released a new estimate of $v_{\text{esc}}$ [T. Piffl et al., Astron. Astrophys. 562, A91 (2014)] that supersedes the previous one [M. C. Smith, et al. Mon. Not. R. Astron. Soc. 379, 755 (2007)], which is of interest in the perspective of reducing the astrophysical uncertainties in DD. Nevertheless, these new estimates cannot be used blindly as they rely on assumptions in the dark halo modeling which induce tight correlations between the escape speed and other local astrophysical parameters. We make a self-consistent study of the implications of the RAVE results on DD assuming isotropic DM velocity distributions, both Maxwellian and ergodic. Taking as references the experimental sensitivities currently achieved by LUX, CRESST-II, and SuperCDMS, we show that (i) the exclusion curves associated with the best-fit points of P14 may be more constraining by up to $\sim 40\%$ with respect to standard limits, because the underlying astrophysical correlations induce a larger local DM density, and (ii) the corresponding relative uncertainties inferred in the low weakly interacting massive particle mass region may be moderate, down to 10–15% below 10 GeV. We finally discuss the level of consistency of these results with other independent astrophysical constraints. This analysis is complementary to others based on rotation curves.

A phenomenological analysis of $D\to K\pi$ and $D_s^{+}\to KK$ decays including both Cabibbo-favored and doubly-Cabibbo-suppressed modes have been presented by employing the present experimental data. SU(3) symmetry breaking effects from the decay constants and form factors have been taken into account in the analysis. Three asymmetries, $R(D^0)$, $R(D^{+})$, and $R(D_s^{+})$, which are generated through interference between Cabbibo-favored and doubly-Cabibbo-suppressed decays, are estimated. Theoretical results agree well with the current measurements.

A search is performed for long-lived massive neutral particles decaying to quark-antiquark pairs. The experimental signature is a distinctive topology of a pair of jets, originating at a secondary vertex. Events were collected with the CMS detector at the CERN LHC in proton-proton collisions at a center-of-mass energy of 8 TeV. The data analyzed correspond to an integrated luminosity of $18.5{\mathrm{fb}}^{-1}$. No significant excess is observed above standard model expectations. Upper limits at 95% confidence level are set on the production cross section of a heavy neutral scalar particle, $H$, in the mass range of 200 to 1000 GeV, decaying promptly into a pair of long-lived neutral $X$ particles in the mass range of 50 to 350 GeV, each in turn decaying into a quark-antiquark pair. For $X$ with mean proper decay lengths of 0.4 to 200 cm, the upper limits are typically $0.5–200\mathrm{fb}$. The results are also interpreted in the context of an R-parity-violating supersymmetric model with long-lived neutralinos decaying into a quark-antiquark pair and a muon. For pair production of squarks that promptly decay to neutralinos with mean proper decay lengths of $2–40\mathrm{cm}$, the upper limits on the cross section are typically $0.5–3\mathrm{fb}$. The above limits are the most stringent on these channels to date.

We present a fully relativistic numerical method for the study of cosmological problems using the Baumgarte-Shapiro-Shibata-Nakamura formalism on a dynamical Friedmann-Lemaître-Robertson-Walker background. This has many potential applications, including the study of the growth of structures beyond the linear regime. We present one such application by reproducing the Lemaître-Tolman-Bondi solution for the collapse of pressureless matter with arbitrary lapse function. The regular and smooth numerical solution at the center of coordinates proceeds in a natural way by relying on the partially implicit Runge-Kutta algorithm described in Montero and Cordero-Carrión [arXiv:1211.5930]. We generalize the usual radiative outer boundary condition to the case of a dynamical background and show the stability and convergence properties of the method in the study of pure gauge dynamics on a de Sitter background.

We study the perturbation induced by a slowly rotating massive object as it passes through a Rindler horizon. It is shown that the passage of this object can be approximately modeled as delta function type tidal distortions hitting the horizon. Further, following the analysis presented by Amsel, Marolf, and Virmani related to the issue of the validity of physical process first law, we establish a condition on the size of the object so that this law holds for the Rindler horizon.

We present two scenarios in the Minimal Supersymmetric Extension of the Standard Model (MSSM) that can lead to an explanation of the excess in the invariant mass distribution of two opposite charged, same flavor leptons, and the corresponding edge at an energy of about 78 GeV, recently reported by the CMS Collaboration. In both scenarios, sbottoms are pair produced, and decay to neutralinos and a b-jet. The heavier neutralinos further decay to a pair of leptons and the lightest neutralino through on-shell sleptons or off-shell neutral gauge bosons. These scenarios are consistent with the current limits on the sbottoms, neutralinos, and sleptons. Assuming that the lightest neutralino is stable we discuss the predicted relic density as well as the implications for dark matter direct detection. We show that consistency between the predicted and the measured value of the muon anomalous magnetic moment may be obtained in both scenarios. Finally, we define the signatures of these models that may be tested at the 13 TeV run of the LHC.

We report a complete calculation of the quark and glue momenta and angular momenta in the proton. These include the quark contributions from both the connected and disconnected insertions. The quark disconnected insertion loops are computed with $Z_4$ noise, and the signal-to-noise ratio is improved with unbiased subtractions. The glue operator is comprised of gauge-field tensors constructed from the overlap operator. The calculation is carried out on a $16^3\times 24$ quenched lattice at $\beta =6.0$ for Wilson fermions with $\kappa =0.154$, 0.155, and 0.1555, which correspond to pion masses at 650, 538, and 478 MeV, respectively. The chirally extrapolated $u$ and $d$ quark momentum/angular momentum fraction is found to be $0.64(5)/0.70(5)$, the strange momentum/angular momentum fraction is $0.024(6)/0.023(7)$, and that of the glue is $0.33(6)/0.28(8)$. The previous study of quark spin on the same lattice revealed that it carries a fraction of 0.25(12) of proton spin. The orbital angular momenta of the quarks are then obtained from subtracting the spin from their corresponding angular momentum components. We find that the quark orbital angular momentum constitutes 0.47(13) of the proton spin with almost all of it coming from the disconnected insertions.

Weak corrections for top-quark pair production at hadron colliders are revisited. Predictions for collider energies of 8 TeV, adopted to the recent LHC run, and for 13 as well as 14 TeV, presumably relevant for the next round of LHC experiments, are presented. Kinematic regions with large momentum transfer are identified, where the corrections become large and may lead to strong distortions of differential distributions, thus mimicking anomalous top-quark couplings. As a complementary case we investigate the threshold region, corresponding to configurations with small relative velocity between top and antitop quarks, which is particularly sensitive to the top-quark Yukawa coupling. We demonstrate, that nontrivial upper limits on this coupling, complementary to those recently derived by the CMS and the ATLAS collaborations, are well within reach of ongoing experiments. We, furthermore, suggest a prescription that allows the implementation of these corrections in current Monte Carlo generators. Furthermore, the weak corrections have been included in the publicly available hathor library. The numerical results presented in this article use the same setup as the recently calculated next-to-next-to-leading-order QCD corrections. The results can thus be combined to give the most precise theoretical predictions.