We numerically analyze the evolution of a two-dimensional dilatonic black hole, within the Callan-Giddings-Harvey-Strominger model. We focus our attention on the finite-mass corrections to the universal evaporation rate which applies at the large-mass limit. Our numerical results confirm a previous theoretical prediction for the first-order ($\propto 1/M$) correction. In addition, our results strongly suggest that the next-order ($\propto 1/M^2$) term vanishes and provide a rough estimate for the third-order term.

We study a relation between the cosmological singularities in classical and quantum theory, comparing the classical and quantum dynamics in some models possessing the big brake singularity—the model based on a scalar field and two models based on a tachyon-pseudo-tachyon field. It is shown that the effect of quantum avoidance is absent for the soft singularities of the big brake type while it is present for the big bang and big crunch singularities. Thus, there is some kind of a classical-quantum correspondence, because soft singularities are traversable in classical cosmology, while the strong big bang and big crunch singularities are not traversable.

We analyze cosmology assuming unitary quantum mechanics, using a tripartite partition into system, observer, and environment degrees of freedom. This generalizes the second law of thermodynamics to “The system’s entropy cannot decrease unless it interacts with the observer, and it cannot increase unless it interacts with the environment.” The former follows from the quantum Bayes theorem we derive. We show that because of the long-range entanglement created by cosmological inflation, the cosmic entropy decreases exponentially rather than linearly with the number of bits of information observed, so that a given observer can reduce entropy by much more than the amount of information her brain can store. Indeed, we argue that as long as inflation has occurred in a non-negligible fraction of the volume, almost all sentient observers will find themselves in a post-inflationary low-entropy Hubble volume, and we humans have no reason to be surprised that we do so as well, which solves the so-called inflationary entropy problem. An arguably worse problem for unitary cosmology involves gamma-ray-burst constraints on the “big snap,” a fourth cosmic doomsday scenario alongside the “big crunch,” “big chill,” and “big rip,” where an increasingly granular nature of expanding space modifies our life-supporting laws of physics. Our tripartite framework also clarifies when the popular quantum gravity approximation $G_{\mu \nu }\approx 8\pi G⟨T_{\mu \nu }⟩$ is valid, and how problems with recent attempts to explain dark energy as gravitational backreaction from superhorizon scale fluctuations can be understood as a failure of this approximation.

We consider the dynamics of a 3-brane embedded in an extra-dimensional Tolman-Bondi Universe where the origin of space plays a special rôle. The embedding is chosen such that the induced matter distribution on the brane respects the spherical symmetry of matter in the extra-dimensional space. The mirage cosmology on the probe brane is studied, resulting in an inhomogeneous and anisotropic four-dimensional cosmology where the origin of space is also special. We then focus on the spatial geometry around the origin and show that the induced geometry, which is initially inhomogeneous and anisotropic, converges to an isotropic and homogeneous Friedmann-Lemaitre 4d space-time. For instance, when a 3-brane is embedded in a 5d matter-dominated model, the 4d dynamics around the origin converge to a Friedmann-Lemaitre Universe in a radiation-dominated epoch. We analyze this isotropization process and show that it is a late-time attractor.

We investigate the $\mathcal{O}({\alpha }_s{v}^2)$ correction to the $e^{+}{e}^{-}\to J/\psi +{\eta }_c$ process in the nonrelativistic QCD (NRQCD) factorization approach. Within some reasonable choices of the relative order-$v^2$ NRQCD matrix elements, we find that including this new ingredient of correction only mildly enhances the existing NRQCD predictions. We have also deduced the asymptotic expressions for the $\mathcal{O}({\alpha }_s{v}^2)$ short-distance coefficients, and reconfirm the early speculation that at next-to-leading order in ${\alpha }_s$, the double logarithm of type ${ln}^2(s/m_c^2)$ appearing in various NRQCD short-distance coefficients is always associated with the helicity-suppressed channels.

The hadron-quark/gluon phase transition is studied in the two-phase model. As a further study of our previous work, both the isoscalar and isovector-vector interactions are included in the Polyakov loop modified Nambu-Jona-Lasinio model for the quark phase. The relevance of the exchange (Fock) terms is stressed and suitably accounted for. The calculation shows that the isovector-vector interaction delays the phase transition to higher densities and the range of the mixed phase correspondingly shrinks. Meanwhile, the asymmetry parameter of quark matter in the mixed phase decreases with the strengthening of this interaction channel. This leads to some possible observation signals being weakened, although still present. We show that these can be rather general effects of a repulsion in the quark phase due to the symmetry energy. This is also confirmed by a simpler calculation with the MIT-bag model. However, the asymmetry parameter of quark matter is slightly enhanced with the inclusion of the isoscalar-vector interaction, but the phase transition will be moved to higher densities. The largest uncertainty on the phase transition lies in the undetermined coupling constants of the vector interactions. In this respect, new data on the mixed phase obtained from heavy-ion collisions at intermediate energies appear very important.

Determining the absolute masses of neutrinos is of fundamental importance in particle physics, nuclear physics, and astrophysics. We conjecture that intrinsic mass relations exist between leptons and quarks. Using these relations and neutrino oscillation data, we show that the inverted neutrino mass hierarchy is strongly disfavored and estimate the absolute neutrino masses to be $m_1={0.21}_{-0.21}^{+1.70}\times {10}^{-4}\mathrm{eV}$, $m_2=(8.7\pm 0.1)\times {10}^{-3}\mathrm{eV}$, and $m_3=(4.9\pm 0.1)\times {10}^{-2}\mathrm{eV}$.

Searches for heavy Majorana neutrinos in $B^{-}$ decays in final states containing hadrons plus a ${\mu }^{-}{\mu }^{-}$ pair have been performed using $0.41{\mathrm{fb}}^{-1}$ of data collected with the LHCb detector in proton-proton collisions at a center-of-mass energy of 7 TeV. The $D^{+}{\mu }^{-}{\mu }^{-}$ and $D^{*+}{\mu }^{-}{\mu }^{-}$ final states can arise from the presence of virtual Majorana neutrinos of any mass. Other final states containing ${\pi }^{+}$, $D_s^{+}$, or $D^0{\pi }^{+}$ can be mediated by an on-shell Majorana neutrino. No signals are found and upper limits are set on Majorana neutrino production as a function of mass, and also on the $B^{-}$ decay branching fractions.

This article studies a numerical relativity approach to the initial value problem in Anti-de Sitter spacetime relevant for dual nonequilibrium evolution of strongly coupled non-Abelian plasma undergoing Bjorken expansion. In order to use initial conditions for the metric obtained in [G. Beuf, M. P. Heller, R. A. Janik, and R. Peschanski, J. High Energy Phys. 10 (2009) 043.] we introduce new, ADM formalism-based scheme for numerical integration of Einstein’s equations with negative cosmological constant. The key novel element of this approach is the choice of lapse function vanishing at fixed radial position, enabling, if needed, efficient horizon excision. Various physical aspects of the gauge theory thermalization process in this setup have been outlined in our companion article [M. P. Heller, R. A. Janik, and P. Witaszczyk, Phys. Rev. Lett. 108, 201602 (2012).]. In this work we focus on the gravitational side of the problem and present full technical details of our setup. We discuss, in particular, the ADM formalism, the explicit form of initial states, the boundary conditions for the metric on the inner and outer edges of the simulation domain, the relation between boundary and bulk notions of time, the procedure to extract the gauge theory energy-momentum tensor and nonequilibrium apparent horizon entropy, as well as the choice of point for freezing the lapse. Finally, we comment on various features of the initial profiles we consider.

By computing the two-loop effective potential of the $D=3$ $\mathcal{N}=1$ supersymmetric Chern-Simons model minimally coupled to a massless self-interacting matter superfield, it is shown that supersymmetry is preserved, while the internal $U(1)$ and the scale symmetries are broken at two-loop order, dynamically generating masses both for the gauge superfield and for the real component of the matter superfield.

We study the thermalization process in the self-interacting curvaton preheating scenario. We solve the evolution of the system with classical lattice simulations with a recently released symplectic PyCOOL program during the resonance and the early thermalization periods and compare the results to the inflaton preheating. After this, we calculate the generated non-Gaussianity with the $\Delta N$ formalism and the separate universe approximation by running a large number of simulations with slightly different initial values. The results indicate a high level of non-Gaussianity. We also use this paper to showcase the various postprocessing functions included with the PyCOOL program that is available from https://github.com/jtksai/PyCOOL.

The Skyrme model is a low energy, effective field theory for QCD that when coupled to a gravitational field provides an ideal semiclassical model to describe neutron stars. We use the Skyrme crystal solution composed of a lattice of $\alpha$-like particles as a building block to construct minimum energy neutron star configurations, allowing the crystal to be strained anisotropically. We find that below 1.49 solar masses the stars’ crystal deforms isotropically and that above this critical mass, it undergoes anisotropic strain. We then find that the maximum mass allowed for a neutron star is 1.90 solar masses, in close agreement with a recent observation of the most massive neutron star yet found. The radii of the computed solutions also match the experimentally estimated values of approximately 10 km.

Direct production of electroweakly charged states may not produce the high-energy jets or the significant missing energy required in many new physics searches at the LHC. However, because these states produce leptons, they are still potentially detectable over the sizeable standard model backgrounds. We show that current LHC Higgs searches, particularly in the $W{W}^{*}$ and $Z{Z}^{*}$ channels, are sensitive to new electroweak states, such as supersymmetric charginos or neutralinos. Indeed, the $1.7{\mathrm{fb}}^{-1}$ Higgs searches can provide the strongest limits in certain regions of parameter space, extending the LEP bound up to $\sim 200\mathrm{GeV}$ in some cases. Additionally, electroweakino production can form an interesting physics background for Higgs searches, especially at low luminosity and statistics. We show that dilepton searches with low missing energy requirements are complementary to existing searches in exploring regions of parameter space where new electroweak states are light or have compressed spectra.

We calculate the leptonic decay constants of $B_{(s)}$ and $D_{(s)}$ mesons in lattice QCD using staggered light quarks and Fermilab bottom and charm quarks. We compute the heavy-light-meson correlation functions on the MILC Asqtad-improved staggered gauge configurations, which include the effects of three light dynamical sea quarks. We simulate with several values of the light valence- and sea-quark masses (down to $\sim m_s/10$) and at three lattice spacings ($a\approx 0.15$, 0.12, and 0.09 fm) and extrapolate to the physical up and down quark masses and the continuum using expressions derived in heavy-light-meson staggered chiral perturbation theory. We renormalize the heavy-light axial current using a mostly nonperturbative method such that only a small correction to unity must be computed in lattice perturbation theory, and higher-order terms are expected to be small. We use the two finer lattice spacings for our central analysis, and we use the third to help estimate discretization errors. We obtain $f_{B^{+}}=196.9(9.1)\mathrm{MeV}$, $f_{B_s}=242.0(10.0)\mathrm{MeV}$, $f_{D^{+}}=218.9(11.3)\mathrm{MeV}$, $f_{D_s}=260.1(10.8)\mathrm{MeV}$, and the $SU(3)$ flavor-breaking ratios $f_{B_s}/f_B=1.229(26)$ and $f_{D_s}/f_D=1.188(25)$, where the numbers in parentheses are the total statistical and systematic uncertainties added in quadrature.

We study the metastable states in the high temperature phase of QCD characterized by nonzero expectation values for the imaginary part of the Polyakov loop. We consider $N_f=2$, 3 dynamical staggered quarks, and carry out simulations at various values of the coupling $\beta$ to observe these states. In particular, we find the value of the coupling (${\beta }_m$) above which the metastable states appear. The resulting value of ${\beta }_m$ corresponds to temperature $T_m\gtrsim 750\mathrm{MeV}$ for $N_f=2$.

Intensive search for a proper and realistic equations of state (EOS) is still continued for studying the phase diagram existing between quark gluon plasma (QGP) and hadron gas (HG) phases. Lattice calculations provide such EOS for the strongly interacting matter at finite temperature ($T$) and vanishing baryon chemical potential (${\mu }_B$). These calculations are of limited use at finite ${\mu }_B$ due to the appearance of notorious sign problem. In the recent past, we had constructed a hybrid model description for the QGP as well as HG phases where we make use of a new excluded-volume model for HG and a thermodynamically-consistent quasiparticle model for the QGP phase and used them further to get QCD phase boundary and a critical point. Since then many lattice calculations have appeared showing various thermal and transport properties of QCD matter at finite $T$ and ${\mu }_B=0$. We test our hybrid model by reproducing the entire data for strongly interacting matter and predict our results at finite ${\mu }_B$ so that they can be tested in future. Finally we demonstrate the utility of the model in fixing the precise location, the order of the phase transition and the nature of $CP$ existing on the QCD phase diagram. We thus emphasize the suitability of the hybrid model as formulated here in providing a realistic EOS for the strongly interacting matter.

If the weak phase of $B_s^0\mathrm{\text{−}}{\overline{B}}_s^0$ mixing ($2{\beta }_s$) is found to be significantly different from zero, this is a clear signal of new physics (NP). However, if such a signal is found, we would like an unambiguous determination of $2{\beta }_s$ in order to ascertain which NP models could be responsible. In addition, in the presence of NP, the width difference $\Delta {\Gamma }_s$ between the two $B_s$ mass eigenstates can be positive or negative, and ideally this sign ambiguity should be resolved experimentally. Finally, in order to see if the NP is contributing to ${\Gamma }_{12}^s$ in addition to $M_{12}^s$, the precise measurement of $|{\Gamma }_{12}^s|$ is crucial. In this paper, we consider several different methods of measuring $2{\beta }_s$ using penguin-free two- and three-body decays with $\overline{b}\to \overline{c}u\overline{s}$ and $\overline{b}\to \overline{u}c\overline{s}$ transitions. We find that the most promising of these is a time-dependent Dalitz-plot analysis of $B_s^0({\overline{B}}_s^0)\to D_{CP}^{0}K\overline{K}$. With this decay, the unambiguous measurements of $2{\beta }_s$ and $\Delta {\Gamma }_s$ are possible, and the weak phase $\gamma$ can also be extracted.

Small black holes potentially created by the Large Hadron Collider could typically carry color charges inherited from their parton progenitors. The dynamics of quarks near such a black hole depends on the curved spacetime geometry as well as the strong interaction due to the color charge of the black hole. We use the AdS/CFT correspondence to study the behavior of strongly coupled quarks near a color-charged black hole. The supergravity background consists of a six-dimensional Schwarzschild-black string AdS soliton, for which the bulk horizon extends from the AdS boundary down to an infrared floor. By going to higher energy scales, the regime of validity of the classical supergravity background can be extended closer to the singularity than might be expected from the four-dimensional perspective. We study the resulting behavior of quarks and compute the rate at which a quark rotating around the black hole loses energy as a function of its mass parameter and angular velocity. We also analyze the behavior of quark-antiquark string configurations and discuss features such as the quark-antiquark screening length.

The most direct experimental signature of a compactified extra dimension is the appearance of towers of Kaluza-Klein particles obeying specific mass and coupling relations. However, such masses and couplings are subject to radiative corrections. In this paper, using techniques developed in previous work, we investigate the extent to which such radiative corrections deform the expected tree-level relations between Kaluza-Klein masses and couplings. As toy models for our analysis, we investigate a flat five-dimensional scalar $\lambda {\varphi }^4$ model and a flat five-dimensional Yukawa model involving both scalars and fermions. In each case, we identify the conditions under which the tree-level relations are stable to one-loop order, and the situations in which radiative corrections modify the algebraic forms of these relations. Such corrections to Kaluza-Klein spectra therefore have the potential to distort the apparent geometry of a large extra dimension.