We explore chiral symmetry breaking in a magnetic field within a Nambu-Jona-Lasinio model of interacting massless quarks including tensor channels. We show that the new interaction channels open up via Fierz identities due to the explicit breaking of the rotational symmetry by the magnetic field. We demonstrate that the magnetic catalysis of chiral symmetry breaking leads to the generation of two independent condensates, the conventional chiral condensate and a spin-one condensate. While the chiral condensate generates a dynamical fermion mass, the new condensate gives rise to a dynamical anomalous magnetic moment for the fermions. As a consequence, the spectrum of the excitations in all Landau levels, except the lowest one, exhibits Zeeman splitting. Since the pair, formed by a quark and an antiquark with opposite spins, possesses a resultant magnetic moment, an external magnetic field can align it giving rise to a net magnetic moment for the ground state. This is the physical interpretation of the spin-one condensate. Our results show that the magnetically catalyzed ground state in QCD is actually richer than previously thought. The two condensates contribute to the effective mass of the LLL quasiparticles in such a way that the critical temperature for chiral symmetry restoration becomes enhanced.

We consider the massive scalar field, the Proca field, and the Fierz-Pauli field in the Schwarzschild spacetime and we focus more particularly on their long-lived quasinormal modes. We show numerically that the associated excitation factors have a strong resonant behavior and we confirm this result analytically from semiclassical considerations based on the properties of the unstable circular geodesics on which a massive particle can orbit the black hole. The conspiracy of (i) the long-lived behavior of the quasinormal modes and (ii) the resonant behavior of their excitation factors induces intrinsic giant ringings, i.e., ringings of a huge amplitude. Such ringings, which are moreover slowly decaying, are directly constructed from the retarded Green function. If we describe the source of the black hole perturbation by an initial value problem with Gaussian initial data, i.e., if we consider the excitation of the black hole from an extrinsic point of view, we can show that these extraordinary ringings are still present. This suggests that physically realistic sources of perturbations should generate giant and slowly decaying ringings and that their existence could be used to constrain ultralight bosonic field theory interacting with black holes.

We consider the nonrotating isolated horizon as an inner boundary of a four-dimensional asymptotically flat spacetime region. Due to the symmetry of the isolated horizon, it turns out that the boundary degrees of freedom can be described by a SO(1, 1) BF theory with sources. This provides a new alternative approach different from the usual one using Chern-Simons theory to study the black hole entropy. To count the microscopical degrees of freedom with the boundary BF theory, the entropy of the isolated horizon can also be calculated in the framework of loop quantum gravity. The leading-order contribution to the entropy coincides with the Bekenstein-Hawking area law only for a particular choice of the Barbero-Immirzi parameter, which is different from its value in the usual approach using Chern-Simons theory. Moreover, the quantum correction to the entropy formula is a constant term rather than a logarithmic term.

We consider a covariant approach to coarse graining a network of interacting Nambu-Goto strings. A transport equation is constructed for a spatially flat Friedmann universe. In Minkowski space and with no spatial dependence this model agrees with a previous model. Thus it likewise converges to an equilibrium with a factorizability property. We present an argument that this property does not depend on a “string chaos” assumption on the correlations between strings. And in contrast to the earlier model, this transport equation agrees with conservation equations for a fluid of strings derived from a different perspective.

The PAMELA collaboration recently released the $e^{+}$ absolute spectrum between 1 and 300 GeV in addition to the positron fraction and the $e^{-}$ spectrum previously measured in the same period. We use the newly developed three-dimensional upgrade of the dragon package to model those data. This code allows us to consider a realistic spiral-arm source distribution in the Galaxy, which impacts the high-energy shape of the propagated spectra. At low energy we treat solar modulation with the HelioProp code and compare its results with those obtained using the usual force-field approximation. We show that all PAMELA data sets can be consistently, and accurately, described in terms of a standard background on top of which a charge symmetric $e^{+}+e^{-}$ extra component with harder injection spectrum is added; this extra contribution is peaked at $\sim 1–10\mathrm{TeV}$ and may originate from a diffuse population of sources located in the Galactic arms. For the first time, we compute the energy required to sustain such a relevant positron flux in the Galaxy, finding that it is naturally compatible with an astrophysical origin. We considered several reference propagation setups; we find that models with a low (or null) reacceleration—tuned against light nuclei data—nicely describe both PAMELA leptonic and hadronic data with no need to introduce a low-energy break in the proton and Helium spectra, as it would be required for high reacceleration models. We also compare our models with the preliminary $e^{-}$ and $e^{+}$ absolute spectra recently measured by AMS-02. We find that those data, differently from what is inferred from the positron fraction alone, favor a high energy cutoff $\sim 10\mathrm{TeV}$ of the extra component if this is uniquely generated in the Galactic arms. A lower cutoff may be allowed if a relevant contribution from powerful $e^{-}+e^{+}$ nearby accelerators (e.g., one or few pulsars) is invoked.

Experimental analyses often use jet binning to distinguish between different kinematic regimes and separate contributions from background processes. To accurately model theoretical uncertainties in these measurements, a consistent description of the jet bins is required. We present a complete framework for the combination of resummed results for production processes in different exclusive jet bins, focusing on Higgs production in gluon fusion as an example. We extend the resummation of the $H+1$-jet cross section into the challenging low transverse momentum region, lowering the uncertainties considerably. We provide combined predictions with resummation for cross sections in the $H+0$-jet and $H+1$-jet bins, and give an improved theory covariance matrix for use in experimental studies. We estimate that the relevant theoretical uncertainties on the signal strength in the $H\to W{W}^{*}$ analysis are reduced by nearly a factor of 2 compared to the current value.

In charmless $B\to PPP$ decays, where $P$ is a pseudoscalar meson, there are six possibilities for the symmetry of the final state. In this paper, for $P=\pi ,K$, we examine the properties of the fully-symmetric final state. We present expressions for all 32 $B\to PPP$ decay amplitudes as a function of both SU(3) reduced matrix elements and diagrams, demonstrating the equivalence of diagrams and SU(3). We also give 25 relations among the amplitudes in the SU(3) limit, as well as those that appear when the diagrams $E/A/PA$ are neglected. In the SU(3) limit, one has the equalities $\sqrt{2}\mathcal{A}(B^{+}\to K^{+}{\pi }^{+}{\pi }^{-}{)}_{\text{FS}}=\mathcal{A}(B^{+}\to K^{+}{K}^{+}{K}^{-}{)}_{\text{FS}}$ and $\sqrt{2}\mathcal{A}(B^{+}\to {\pi }^{+}{K}^{+}{K}^{-}{)}_{\text{FS}}=\mathcal{A}(B^{+}\to {\pi }^{+}{\pi }^{+}{\pi }^{-}{)}_{\text{FS}}$, where FS denotes the fully-symmetric final state. These provide good tests of the standard model that can be carried out now by the LHCb Collaboration.

The interaction and propagation of $\overline{B}$ mesons with light mesons, $N$ and $\mathrm{\Delta }$, is studied within a unitarized approach based on effective models that are compatible with chiral and heavy-quark symmetries. We find several heavy-quark spin doublets in the open bottom sectors, where $\overline{B}$ and ${\overline{B}}^{*}$ mesons are present. In the meson sector we find several resonant states, among them a $B_0$ and a $B_1$ with masses 5530 MeV and 5579 MeV as well as $B_{s0}^{*}$ and $B_{s1}^{*}$ narrow states at 5748 MeV and 5799 MeV, respectively. They form two doublets with no experimental identification yet, the first one being the bottom counterpart of the $D_0(2400)$ and $D_1(2430)$ states, and the second bottom doublet associated to the ubiquitous $D_{s0}^{*}(2317)$ and the $D_{s1}(2460)$. In the baryon sector, several ${\mathrm{\Lambda }}_b$ and ${\mathrm{\Sigma }}_b$ doublets are identified, among them the one given by the experimental ${\mathrm{\Lambda }}_b(5910)$ and ${\mathrm{\Lambda }}_b^{*}(5921)$. Moreover, one of our states, the ${\mathrm{\Sigma }}_b^{*}(5904)$, turns out to be the bottom counterpart of the experimental ${\mathrm{\Sigma }}^{*}(1670)$ and predicted ${\mathrm{\Sigma }}_c^{*}(2550)$, which is a case for discovery. We finally analyze different transport coefficients for the $\overline{B}$ meson in hot matter, such as those formed in heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC). For RHIC/LHC energies, the main contribution to the coefficients comes from the interaction of $\overline{B}$ mesons with pions. However, we also include the effects of baryonic density which might be sizable at temperatures $T\lesssim 100\mathrm{MeV}$, as the chemical potential is expected to increase in the last stages of the expansion. We conclude that although the relaxation time decreases with larger baryonic densities, the $\overline{B}$ meson does not thermalize at RHIC/LHC energies, representing an ideal probe for the initial bottom distribution.

We study the QCD phases and their transitions in the $2+1$ flavor Nambu–Jona-Lasinio model, with a focus on the interface effects such as the interface tension, the interface entropy, and the critical bubble size in the coexistence region of the first-order phase transitions. Our results show that under the thin-wall approximation, the interface contribution to the total entropy density changes its discontinuity scale in the first-order phase transition. However, the entropy density of the dynamical chiral symmetry (DCS) phase is always greater than that of the dynamical chiral symmetry broken (DCSB) phase in both the heating and hadronization processes. To address this entropy puzzle, the thin-wall approximation is evaluated in the present work. We find that the puzzle can be attributed to an overestimate of the critical bubble size at low temperature in the hadronization process. With an improvement on the thin-wall approximation, the entropy puzzle is well solved with the total entropy density of the hadron-DCSB phase exceeding apparently that of the DCS-quark phase at low temperature.

Two-particle azimuthal angle correlations have been proposed to be one of the most direct and sensitive probes to access the underlying gluon dynamics involved in hard scatterings. In anticipation of an electron-ion collider (EIC), detailed studies of dihadron correlation measurements in electron-proton and electron-ion collisions at an EIC have been performed. The impact of such measurements on the understanding of the different gluon distribution functions, as a clean signature for gluon saturation and to constrain saturation models further, has been explored. It is shown that dihadron correlation measurements will be one of the key methods to probe gluon saturation phenomena at a future EIC.

After the discovery of the 125 GeV scalar boson with gauge properties similar to the Standard Model (SM) Higgs, the search for beyond the SM interactions will focus on studying the discovered particles’ coupling properties more precisely and shedding light on the relation of fermion masses with the electroweak vacuum. The large mass of the top quark and the SM-predicted order one top Yukawa coupling is a natural candidate for beyond the SM physics, though experimentally challenging to constrain. In this paper, we argue that investigating angular correlations in $pp\to tHj$ production provides an excellent handle to constrain the top Yukawa coupling $y_t$ via direct measurements, even when we focus on rare exclusive final states. We perform a hadron-level analysis and show that we may expect to constrain $y_t\gtrsim 0.5y_t^{\mathrm{SM}}$ at 95%–99% confidence level at the high luminosity LHC using semileptonic top decays and $H\to \gamma \gamma$ alone, by employing a two-channel measurement approach.

Motivated by the recent results from Daya Bay, Reno and Double Chooz Collaborations, we study the consequences of small departures from exact $\mu -\tau$ symmetry in the neutrino sector, to accommodate a nonvanishing value of the element $V_{e3}$ from the leptonic mixing matrix. Within the seesaw framework, we identify simple patterns of Dirac mass matrices that lead to approximate $\mu -\tau$ symmetric neutrino mass matrices, which are consistent with the neutrino oscillation data and lead to nonvanishing mixing angle $V_{e3}$ as well as precise predictions for the $CP$-violating phases. We also show that there is a transparent link between neutrino mixing angles and seesaw parameters, which we further explore within the context of leptogenesis as well as double beta decay phenomenology.

High-quality charged current quasielastic scattering data have recently been reported for both muon neutrinos and antineutrinos from several accelerator-based neutrino experiments. Measurements from MiniBooNE were the first to indicate that more complex nuclear effects, now thought to be the result of nucleon pair correlations, may contribute to neutrino quasielastic samples at a much higher significance than previously assumed. These findings are now being tested by $\mathrm{MINER}\nu \mathrm{A}$ and other contemporary neutrino experiments. Presented here is a comparison of data from MiniBooNE and $\mathrm{MINER}\nu \mathrm{A}$ to a few example parametrizations of these nuclear effects. It has been demonstrated that such effects may bias future measurements of neutrino oscillation parameters, and so this issue continues to press the neutrino community. A comparison of data over a large range of neutrino energies is one approach to exploring the extent to which such nucleon correlations may influence our understanding and subsequent modeling of neutrino quasielastic scattering.

We report on mass and lifetime measurements of several ground state charmed and bottom baryons, using a data sample corresponding to $9.6{\mathrm{fb}}^{-1}$ from $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ and recorded with the Collider Detector at Fermilab. Baryon candidates are reconstructed from data collected with an online event selection designed for the collection of long-lifetime heavy-flavor decay products and a second event selection designed to collect $J/\psi \to {\mu }^{+}{\mu }^{-}$ candidates. First evidence for the process ${\mathrm{\Omega }}_b^{-}\to {\mathrm{\Omega }}_c^0{\pi }^{-}$ is presented with a significance of $3.3\sigma$. We measure the following baryon masses: $$\begin{gathered} M({\mathrm{\Xi }}_c^0)=2470.85\pm 0.24(\text{stat})\pm 0.55(\text{syst})\mathrm{MeV}/c^2, \\ M({\mathrm{\Xi }}_c^{+})=2468.00\pm 0.18(\text{stat})\pm 0.51(\text{syst})\mathrm{MeV}/c^2, \\ M({\mathrm{\Lambda }}_b)=5620.15\pm 0.31(\text{stat})\pm 0.47(\text{syst})\mathrm{MeV}/c^2, \\ M({\mathrm{\Xi }}_b^{-})=5793.4\pm 1.8(\text{stat})\pm 0.7(\text{syst})\mathrm{MeV}/c^2, \\ M({\mathrm{\Xi }}_b^0)=5788.7\pm 4.3(\text{stat})\pm 1.4(\text{syst})\mathrm{MeV}/c^2,\text{and} \\ M({\mathrm{\Omega }}_b^{-})=6047.5\pm 3.8(\text{stat})\pm 0.6(\text{syst})\mathrm{MeV}/c^2. \end{gathered}$$The isospin splitting of the ${\mathrm{\Xi }}_b^{-,0}$ states is found to be $M({\mathrm{\Xi }}_b^{-})-M({\mathrm{\Xi }}_b^0)=4.7\pm 4.7(\text{stat})\pm 0.7(\text{syst})\mathrm{MeV}/c^2$. The isospin splitting of the ${\mathrm{\Xi }}_c^{0,+}$ states is found to be $M({\mathrm{\Xi }}_c^0)-M({\mathrm{\Xi }}_c^{+})=2.85\pm 0.30(\text{stat})\pm 0.04(\text{syst})\mathrm{MeV}/c^2$. The following lifetime measurements are made: $$\begin{gathered} \tau ({\mathrm{\Lambda }}_b)=1.565\pm 0.035(\text{stat})\pm 0.020(\text{syst})\mathrm{ps}, \\ \tau ({\mathrm{\Xi }}_b^{-})=1.32\pm 0.14(\text{stat})\pm 0.02(\text{syst})\mathrm{ps}, \\ \tau ({\mathrm{\Omega }}_b^{-})=1.66_{-0.40}^{+0.53}(\text{stat})\pm 0.02(\text{syst})\mathrm{ps}. \end{gathered}$$

Phase II of SIMPLE (Superheated Instrument for Massive ParticLe Experiments) searched for astroparticle dark matter using superheated liquid ${\mathrm{C}}_2{\mathrm{ClF}}_5$ droplet detectors. Each droplet generally requires an energy deposition with linear energy transfer (LET) $\gtrsim 150\mathrm{keV}/\mu \mathrm{m}$ for a liquid-to-gas phase transition, providing an intrinsic rejection against minimum ionizing particles of order ${10}^{-10}$, and reducing the backgrounds to primarily $\alpha$ and neutron-induced recoil events. The droplet phase transition generates a millimetric-sized gas bubble that is recorded by acoustic means. We describe the SIMPLE detectors, their acoustic instrumentation, and the characterizations, signal analysis and data selection, which yield a particle-induced, “true nucleation” event detection efficiency of better than 97% at a 95% C.L. The recoil-$\alpha$ event discrimination, determined using detectors first irradiated with neutrons and then doped with alpha emitters, provides a recoil identification of better than 99%; it differs from those of COUPP and PICASSO primarily as a result of their different liquids with lower critical LETs. The science measurements, comprising two shielded arrays of fifteen detectors each and a total exposure of 27.77 kgd, are detailed. Removal of the 1.94 kgd Stage 1 installation period data, which had previously been mistakenly included in the data, reduces the science exposure from 20.18 to 18.24 kgd and provides new contour minima of ${\sigma }_p=4.3\times {10}^{-3}\mathrm{pb}$ at $35\mathrm{GeV}/{\mathrm{c}}^2$ in the spin-dependent sector of astroparticle dark matter–proton interactions and ${\sigma }_N=3.6\times {10}^{-6}\mathrm{pb}$ at $35\mathrm{GeV}/{\mathrm{c}}^2$ in the spin-independent sector. These results are examined with respect to the fluorine spin and halo parameters used in the previous data analysis.

We consider the vacuum energy of the electromagnetic field in systems characterized by a constant conductivity using the zeta-regularization approach. The interaction in two cases is investigated: two infinitely thin parallel sheets and an infinitely thin spherical shell. We found that the Casimir energy for the planar system is always attractive and it has the same characteristic distance dependence as the interaction for two perfect semi-infinite metals. The Casimir energy for the spherical shell depends on the inverse radius of the sphere, but it maybe negative or positive depending on the value of the conductivity. If the conductivity is less than a certain critical value, the interaction is attractive, otherwise the Casimir force is repulsive regardless of the spherical shell radius.

We extend and improve the modeling and analysis of large-amplitude, sharp inflationary steps for second order corrections required by the precision of the Planck cosmic microwave background power spectrum and for arbitrary Dirac-Born-Infeld sound speed. With two parameters, the amplitude and frequency of the resulting oscillations, step models improve the fit by $\mathrm{\Delta }{\chi }^2=-11.4$. Evidence for oscillations damping before the Planck beam scale is weak: damping only improves the fit to $\mathrm{\Delta }{\chi }^2=-14.0$ for one extra parameter, if step and cosmological parameters are jointly fit, in contrast to analyses which fix the latter. Likewise, further including the sound speed as a parameter only marginally improves the fit to $\mathrm{\Delta }{\chi }^2=-15.2$ but has interesting implications for the lowest multipole temperature and polarization anisotropy. Since chance features in the noise can mimic these oscillatory features, we discuss tests from polarization power spectra, lensing reconstruction and squeezed and equilateral bispectra that should soon verify or falsify their primordial origin.

We construct a consistent closure for the beta functions of the cosmological and Newton’s constants by evaluating the influence that the anomalous dimensions of the fluctuating metric and ghost fields have on their renormalization group flow. In this generalized framework we confirm the presence of a UV attractive non-Gaussian fixed point, which we find characterized by real critical exponents. Our closure method is general and can be applied systematically to more general truncations of the gravitational effective average action.

We consider a gedanken experiment of the scattering of a current $j=-\frac{1}{4}{F}_{\mu \nu }^i{F}_{\mu \nu }^i$ off a large nucleus to study the gluon saturation at the small-$x$ limit and compute the Sudakov factor of this process through a one-loop calculation. The differential cross section is expressed in terms of the Sudakov resummation, in which the collinear and the rapidity divergences are subtracted.

High-energy evolution equations, such as the Balitsky-Fadin-Kuraev-Lipatov (BFKL), Balitsky-Kovchegov (BK) or Jalilian-Marian–Iancu–McLerran–Weigert–Leonidov–Kovner equations, aim at resumming the high-energy (next-to-)leading logarithms appearing in QCD perturbative series. However, the standard derivations of these equations are performed in a strict high-energy limit, whereas such equations are then applied to scattering processes at large but finite energies. For this reason, there is typically a slight mismatch between the leading logs resummed by these evolution equations without finite-energy corrections and the leading logs actually present in the perturbative expansion of any observable. That mismatch is one of the sources of large corrections at next-to-leading-order and next-to-leading-logarithmic accuracy. In the case of the BFKL equation in momentum space, this problem is solved by including a kinematical constraint in the kernel, which is the most important finite-energy correction. In this paper, such an improvement of kinematics is performed in mixed space (transverse positions and $k^{+}$) and with a factorization scheme in the light-cone momentum $k^{+}$ (in a frame in which the projectile is right-moving and the target left-moving). This is the usual choice of variables and factorization scheme for the the BK equation. A kinematically improved version of the BK equation is provided, consistent at finite energies. The results presented here are also a necessary step towards having the high-energy limit of QCD (including gluon saturation) quantitatively under control beyond strict leading-logarithmic accuracy.