The high prompt production cross section of $X(3872)$ at hadron colliders has shown to be very informative about the quark nature of the $X$, $Y$, $Z$ states. We present here a number of results on $X$ production in $pp(\overline{p})$ collisions obtained with Monte Carlo hadronization methods and illustrate what can be learned from their use to improve our understanding of exotic states. In particular, a comparison between antideuteron and $X$ production cross sections is proposed. Hadronization might be the key to solve the problem of the extra states expected in diquark-antidiquark models which are naturally favored after the recent confirmation of the $Z(4430)$ tetraquark, together with its lower partners $Z_c(3900)$ and $Z_c^{\prime }(4020)$.

We present two exact relations, valid for any dilepton invariant mass region (large and low recoil) and independent of any effective Hamiltonian computation, between the observables $P_i$ and $P_i^{CP}$ of the angular distribution of the four-body decay $B\to K^{*}(\to K\pi )l^{+}{l}^{-}$. These relations emerge out of the symmetries of the angular distribution. We discuss the implications of these relations under the (testable) hypotheses of no scalar or tensor contributions and no New Physics weak phases in the Wilson coefficients. Under these hypotheses, there is a direct relation among the observables $P_1$, $P_2$, and $P_{4,5}^{\prime }$. This can be used as an independent consistency test of the measurements of the angular observables. Alternatively, these relations can be applied directly in the fit to data, reducing the number of free parameters in the fit. This opens up the possibility of performing a full angular fit of the observables with existing data sets. An important consequence of the found relations is that a priori two different measurements, namely the measured position of the zero ($q_0^2$) of the forward-backward asymmetry $A_{\mathrm{FB}}$ and the value of $P_5^{\prime }$ evaluated at this same point, are related by $P_4^2(q_0^2)+P_5^2(q_0^2)=1$. Under the hypotheses of real Wilson coefficients and $P_4^{\prime }$ being SM-like, we show that the higher the position of $q_0^2$, the smaller should be the value of $P_5^{\prime }$ evaluated at the same point. A precise determination of the position of the zero of $A_{\mathrm{FB}}$ together with a measurement of $P_4^{\prime }$ (and $P_1$) at this position can be used as an independent experimental consistency test of the anomaly in $P_5^{\prime }$. We also point out the existence of upper and lower bounds for $P_1$, namely $P_5^{\prime 2}-1\le P_1\le 1-P_4^{\prime 2}$, which constrains the physical region of the observables.

The insular nature of the Standard Model may be explained if the Higgs mass parameter is only sensitive to quantum corrections from physical states. Starting from a scale-free electroweak sector at tree level, we postulate that quantum effects of heavy right-handed neutrinos induce a mass term for a scalar weak doublet that contains the dark matter particle. In turn, below the scale of heavy neutrinos, the dark matter sector sets the scale of the Higgs potential. We show that this framework can lead to a Higgs mass that respects physical naturalness, while also providing a viable scalar dark matter candidate, realistic light neutrino masses, and the baryon asymmetry of the Universe via thermal leptogenesis. The proposed scenario can remain perturbative and stable up to the Planck scale, thereby accommodating simple extensions to include a high-scale ($\sim 2\times 10^{16}\mathrm{GeV}$) inflationary sector, implied by recent measurements. In that case, our model typically predicts that the dark matter scalar is close to 1 TeV in mass and could be accessible in near future direct detection experiments.

We consider charged rotating BTZ black holes in $2+1$ dimensions and obtain $1+1$-dimensional holographic superconductors on a spatial circle in the context of the ${\mathrm{AdS}}_3/{\mathrm{CFT}}_2$ correspondence. The charged condensate for the boundary superconductor is computed both in the analytic and the numerical framework in a probe limit and a low angular momentum approximation. A critical value of the angular momentum for the onset of superconductivity is established. We also numerically compute the electrical conductivity of the $1+1$-dimensional boundary theory on a circle. The conductivity exhibits a dependence on angular momentum of the rotating black hole both for the normal and the superconducting phase of the boundary field theory. The significance of the boundary field theory in the context of a Fermi-Luttinger liquid on a circle is discussed.

A relevant perturbation of the entanglement entropy of a sphere is examined holographically near the UV fixed point. Varying the conformal dimension of the relevant operator, we obtain three different sectors: (1) the entanglement entropy is stationary and the perturbative expansion is well defined with respect to the relevant coupling, (2) the entropy is stationary, but the perturbation fails, (3) the entropy is neither stationary nor perturbative. We compare our holographic results with the numerical calculation for a free massive scalar field in three dimensions, and find a qualitative agreement between them. We speculate that these statements hold for any relevant perturbation in any quantum field theory invariant under the Poincaré symmetry.

We study the dependence of the electromagnetic luminosity—produced by interactions of force-free magnetospheres—on dipole inclinations in binary neutron star systems. We show that this interaction extracts kinetic energy from the system and powers a Poynting flux with a strong dependence on the dipole orientations. This dependence can be linked to the reconnection and redistribution of the magnetic field as the stars interact. Although the details of the Poynting luminosity are very much dependent on the orientation, all the cases considered here nevertheless radiate a large Poynting flux. This robust emission suggests that the premerger stage of binary neutron star systems can yield interesting electromagnetic counterparts to gravitational wave events.

A canonical pseudo-Nambu-Goldstone boson (pNGB) can play the role of a dark energy field responsible for present cosmic acceleration. Confronted with the recent cosmological data, we find that the pNGB field requires a spontaneous symmetry breaking scale $f$ close to $M_P$ and that the initial field value be fine-tuned. It is difficult to achieve a large $f$ in a theoretically consistent setup. A possible resolution can be achieved by increasing the Hubble friction in well-motivated particle physics models in the general setup of modified gravity theories. We show two phenomenological examples of this setup where the standard pNGB action has been modified by introducing terms motivated by Galileon cosmology. We confront those examples with the recent supernovae, PLANCK and baryon acoustic oscillation data. We find that moderate values of the dimensionless constants that increase the friction make $f\ll M_P$ and the generic initial conditions also favorable by the data. We also comment on how the fifth-force constraints arising in these modified theories can be evaded.

Extremal black holes tend to expel magnetic and electric fields. Fields are unable to reach the horizon because the length of the black hole throat blows up in the extremal limit. The length of the throat is related to the amount of entanglement between modes on either side of the horizon. So it is natural to try to relate the black hole Meissner effect to entanglement. We derive the black hole Meissner effect directly from the low temperature limit of two-point functions in the Hartle-Hawking vacuum. Then we discuss several new examples of the black hole Meissner effect, its applications to astrophysics, and its relationship to gauge invariance.

We propose different scenarios where a keV dark matter annihilates to produce a monochromatic signal. The process is generated through the exchange of a light scalar of mass of order 300 keV–50 MeV coupling to photon through loops or higher-dimensional operators. For natural values of the couplings and scales, the model can generate a gamma-ray line which can fit with the recently identified 3.5 keV x-ray line.

We obtain the baryon number density, $n$, and the excess contribution to the pressure, $\mathrm{\Delta }P$, at finite chemical potential, ${\mu }_B$, and temperature, $T$, by resumming the Taylor series expansion in a lattice computation with lattice spacing of $1/(4T)$ and two flavors of quarks at three different quark masses. The method proceeds by giving a critical ${\mu }_B$ and limits on the critical exponent, and permits reliable estimations of the errors in resummed quantities. We find that $n$ and $\mathrm{\Delta }P$ are insensitive to the quark mass. We also report the bulk isothermal compressibility, $\kappa$, over a range of $T$ and ${\mu }_B$.

The fixed-target Main Injector Particle Production (MIPP) experiment, Fermilab E907, was designed to measure the production of hadrons from the collisions of hadrons of momenta ranging from 5 to $120\mathrm{GeV}/\mathrm{c}$ on a variety of nuclei. These data will generally improve the simulation of particle detectors and predictions of particle beam fluxes at accelerators. The spectrometer momentum resolution is between 3% and 4%, and particle identification is performed for particles ranging between 0.3 and $80\mathrm{GeV}/\mathrm{c}$ using $dE/dx$, time-of-flight, and Cherenkov radiation measurements. MIPP collected $1.42\times {10}^6$ events of 120 GeV Main Injector protons striking a target used in the Neutrinos at the Main Injector facility at Fermilab. The data have been analyzed and we present here charged pion yields per proton on target determined in bins of longitudinal and transverse momentum between 0.5 and $80\mathrm{GeV}/\mathrm{c}$, with combined statistical and systematic relative uncertainties between 5% and 10%.

We present new constraints on the spectral index $n_T$ of tensor fluctuations from the recent data obtained by the BICEP2 experiment. We found that the BICEP2 data alone slightly prefer a positive, “blue,” spectral index with $n_T=1.36\pm 0.83$ at 68% C.L. However, when a TT prior on the tensor amplitude coming from temperature anisotropy measurements is assumed, we get $n_T=1.67\pm 0.53$ at 68% C.L., ruling out a scale-invariant $n_T=0$ spectrum at more than three standard deviations. These results are at odds with current bounds on the tensor spectral index coming from pulsar timing, big bang nucleosynthesis, and direct measurements from the LIGO experiment. Considering only the possibility of a “red” $n_T<0$ spectral index, we obtain the lower limit $n_T>-0.76$ at 68% C.L. ($n_T>-0.09$ when a TT prior is included).

A holographic superconductor is constructed in the background of a massive gravity theory. In the normal state without condensation, the conductivity exhibits a Drude peak that approaches a delta function in the massless gravity limit as studied by David Vegh. In the superconducting state, besides the infinite dc conductivity, the ac conductivity has Drude behavior at low frequency followed by a power-law fall. These results are in agreement with that found earlier by Horowitz and Santos, who studied a holographic superconductor with an implicit periodic potential beyond the probe limit. The results also agree with measurements on some cuprates.

We study the dynamics of $SU(2{)}_L\times U(1{)}_Y$ electroweak gauge fields during and after Higgs inflation. In particular, we investigate configurations of the gauge fields during inflation and find the gauge fields remain topologically nontrivial. We also find that the gauge fields grow due to parametric resonances caused by oscillations of a Higgs field after inflation. We show that the Chern-Simons number also grows significantly. Interestingly, the parametric amplification gives rise to sizable magnetic fields after the inflation whose final amplitudes depend on the anisotropy survived during inflation.

We show that the entropy of certain conformal interfaces between $N=(2,2)$ sigma models that belong to the same moduli space has a natural geometric interpretation in the large volume limit as Calabi’s diastasis function. This is an extension of the well-known relation between the quantum Kähler potential and the overlap of canonical Ramond—Ramond ground states in $N=(2,2)$ models.

One problem in the application of the Skyrme model to nuclear physics is that it predicts too large a value for the compression modulus of nuclear matter. Here we investigate the thermodynamics of the BPS Skyrme model at zero temperature and calculate its equation of state. Among other results, we find that classically (i.e. without taking into account quantum corrections) the compressibility of BPS Skyrmions is, in fact, infinite, corresponding to a zero compression modulus. This suggests that the inclusion of the BPS submodel into the Skyrme model Lagrangian may significantly reduce this too-large value, providing further evidence for the claim that the BPS Skyrme model may play an important role in the description of nuclei and nuclear matter.

In models with a light scalar field (the “acceleron”) coupled to neutrinos, neutrino masses depend on neutrino density. The resulting coupled system of mass varying neutrinos (MaVaNs) and the acceleron can act as a negative pressure fluid and is a candidate for dark energy [R. Fardon et al. J. Cosmol. Astropart. Phys. 10 (2004) 005]. MaVaNs also allow for higher $\mathrm{\Sigma }{\mathit{m}}_{\mathit{\nu }}$ than terrestrial bounds, giving late forming warm dark matter. In this paper we study the effect of increasing neutrino mass on the cosmic microwave background (CMB) spectrum, implementing MaVaNs cosmology using CMBEASY. We find that the CMB spectrum is only affected at very low multipoles. Cosmic variance allows for significant warm dark matter at late times. This implies that in MaVaNs cosmology ${\sigma }_8$ as determined by the CMB may not be a good determinant of structure evolution at late times, potentially reducing the tension between ${\sigma }_8$ as reported by Planck Collaboration [P. A. R. Ade et al. (Planck Collaboration) arXiv:1303.5080] without increasing the tension in the Planck determined value of Hubble’s constant. In addition, in MaVaNs theories, CMB data do not necessarily constrain possible neutrino mass results in terrestrial experiments.

We investigate whether the baryon asymmetry of the Universe is explained in the framework of the supersymmetric extension of the Standard Model with $R$-parity violating interactions. It is shown that the Affleck-Dine mechanism naturally works via a trilinear interaction $LL{E}^c$, $LQ{D}^c$, or $U^c{D}^c{D}^c$, if the magnitude of the coupling corresponding to the operator $\lambda$, ${\lambda }^{\prime }$, or ${\lambda }^{\prime \prime }$ is sufficiently small. The formation of Q-balls and their subsequent evolution are also discussed. The present baryon asymmetry can be explained in the parameter region where $R$-parity is mildly violated ${10}^{-9}\lesssim \lambda ,{\lambda }^{\prime },{\lambda }^{\prime \prime }\lesssim {10}^{-6}$ and the mass of the gravitino is relatively heavy $m_{3/2}\gtrsim {10}^4\mathrm{GeV}$. On the other hand, it is difficult to explain the present baryon asymmetry for larger values of $R$-parity violating couplings $\lambda ,{\lambda }^{\prime },{\lambda }^{\prime \prime }\gtrsim {10}^{-5}$, since Q-balls are likely to be destructed in the thermal environment and the primordial baryon number is washed away.