Semileptonic decays of B mesons are known to be very sensitive to any new physics effects. Amongst various possibilities the transition at the quark level $\overrightarrow{b}d{\mathcal{l}}^{+}{\mathcal{l}}^{-}$ is more suited than $\overrightarrow{b}s{\mathcal{l}}^{+}{\mathcal{l}}^{-}$ for the purpose of studying CP violation. Here in this work we will discuss the effects of supersymmetry on the various experimentally measurable quantities such as the decay rate, forward backward asymmetry, various polarization asymmetries, and CP violation asymmetries in the exclusive channels $\overrightarrow{B}\pi {\mathcal{l}}^{+}{\mathcal{l}}^{-}$ and $\overrightarrow{B}\rho {\mathcal{l}}^{+}{\mathcal{l}}^{-}.$ We will focus mainly on the neutral Higgs boson effects on these measurements, with a view to eliciting information about possible CP violating as well as non-Hermitian terms in the effective Hamiltonian.

We consider dilepton production in high energy proton-nucleus (and very forward nucleus-nucleus) collisions. Treating the target nucleus as a color glass condensate and describing the projectile proton (nucleus) as a collection of quarks and gluons as in the parton model, we calculate the differential cross section for dilepton production in quark-nucleus scattering and show that it is very sensitive to the saturation scale characterizing the target nucleus.

We present next-to-next-to leading logarithmic (NNLL) results for the double differential decay width $d\Gamma \left(\overrightarrow{b}{X}_s{\mathcal{l}}^{+}{\mathcal{l}}^{-}\right)/\left[dŝd\cos \right(\theta \left)\right],$ where $s=ŝm_b^2$ is the invariant mass squared of the lepton pair and θ is the angle between the momentum of the b quark and the ${\mathcal{l}}^{+},$ measured in the rest frame of the lepton pair. From these results we also derive NNLL results for the lepton forward-backward asymmetries, as these quantities are known to be very sensitive to new physics. While the principal steps in the calculation of the double differential decay width are the same as for $d\Gamma \left(\overrightarrow{b}{X}_s{\mathcal{l}}^{+}{\mathcal{l}}^{-}\right)/dŝ,$ which is already known to NNLL precision, genuinely new calculations for the combined virtual and gluon bremsstrahlung corrections associated with the operators $O_7,$ $O_9,$ and $O_{10}$ are necessary. In this paper, we neglected certain other bremsstrahlung contributions, which are known to have only a small impact on $d\Gamma \left(\overrightarrow{b}{X}_s{\mathcal{l}}^{+}{\mathcal{l}}^{-}\right)/dŝ.$ We find that the NNLL corrections drastically reduce the renormalization scale (μ) dependence of the forward-backward asymmetries. In particular, $s_0,$ the position at which the forward-backward asymmetries vanish, is essentially free of uncertainties due to the renormalization scale at NNLL precision. We find $s_0^{\mathrm{NNLL}}=0.162\mathrm{}\pm 0.005,$ where the error is dominated by the uncertainty in $m_c{/m}_b.$ This is to be compared with $s_0^{\mathrm{NLL}}=0.144\mathrm{}\pm 0.020,$ where the error is dominated by uncertainties due to the choice of μ.

We discuss one-loop five-parton amplitudes with two-quark, two-photon, or three-photon external legs. The amplitudes are required to evaluate the NLO corrections for the $\gamma \gamma \mathrm{jet}$ production process at hadron colliders. The results have been already discussed by several groups in terms of QCD amplitudes. Here, we present a more straightforward version of one-loop calculations without using the QCD amplitudes.

We compute corrections of relative order $v^4$ to the rates for the decays of ${}^1{S}_0$ heavy quarkonium into two photons and into light hadrons and for the decays of ${}^3{S}_1$ heavy quarkonium into a lepton pair and into light hadrons. In particular, we compute the coefficients of the decay operators that have the same quantum numbers as the heavy quarkonium. We also confirm previous calculations of the order-$v^2$ corrections to these rates. We find that the $v$ expansion converges well for the decays of ${}^1{S}_0$ heavy quarkonium and for the decay of ${}^3{S}_1$ heavy quarkonium into a lepton pair. Large higher-order-in-$v$ corrections appear in the decay of ${}^3{S}_1$ heavy quarkonium into light hadrons. However, we find that the series of coefficients of operators with ${}^3{S}_1$ quantum numbers, which yields a large correction in order $v^2,$ yields a smaller correction in order $v^4.$

We present an updated analysis of the current solar neutrino data in terms of three-flavor oscillations, including the additional constraints coming from terrestrial neutrino oscillation searches at the CHOOZ (reactor), Super-Kamiokande (atmospheric), and KEK-to-Kamioka (accelerator) experiments. The best fit is reached for the subcase of two-family mixing, and the additional admixture with the third neutrino is severely limited. We discuss the relevant features of the globally allowed regions in the oscillation parameter space, as well as their impact on the amplitude of possible $\mathrm{CP}$-violation effects at future accelerator experiments and on the reconstruction accuracy of the mass-mixing oscillation parameters at the KamLAND reactor experiment.

The inclusive cross section for $J/\psi$ production times the branching ratio $B(J/\overrightarrow{\psi }{\mu }^{+}{\mu }^{-})$ has been measured in the forward pseudorapidity region: $B\times d\sigma [\overline{p}+\overrightarrow{p}J/\psi {(p}_T>10\mathrm{}\mathrm{GeV}/c,2.1<|\eta |<2.6)+X]/\mathrm{d}\eta =192\mathrm{}\pm 9(\mathrm{stat})\pm 29(\mathrm{syst})\mathrm{pb}.$ The results are based on $74.1\pm 5.2{\mathrm{pb}}^{-1}$ of data collected by the CDF Collaboration at the Fermilab Tevatron Collider. The measurements extend earlier measurements of the D0 Collaboration to higher $p_T^{J/\psi }.$ In the kinematic range where the experiments partially overlap, these data are in good agreement with previous measurements.

We study a simple analytic solution to Einstein’s field equations describing a thin spherical shell consisting of collisionless particles in circular orbit. We then apply two independent criteria for the identification of circular orbits, which have recently been used in the numerical construction of binary black hole solutions, and find that both yield equivalent results. Our calculation illustrates these two criteria in a particularly transparent framework and provides further evidence that the deviations found in those numerical binary black hole solutions are not caused by the different criteria for circular orbits.

We consider quantum field theory on a spacetime representing the big-crunch–big-bang transition postulated in ekpyrotic or cyclic cosmologies. We show via several independent methods that an essentially unique matching rule holds connecting the incoming state, in which a single extra dimension shrinks to zero, to the outgoing state in which it reexpands at the same rate. For free fields in our construction there is no particle production from the incoming adiabatic vacuum. When interactions are included the particle production for fixed external momentum is finite at the tree level. We discuss a formal correspondence between our construction and quantum field theory on de Sitter spacetime.

In theories with flat directions containing vortices, such as supersymmetric QED, there is a vacuum selection effect in the allowed asymptotic configurations. We explain the role played by gauge fields in this effect and give a simple criterion for determining what vacua will be chosen, namely, those that minimize the vector mass. We then consider the effect of vacuum selection on stable (Bogomol’nyi-Prasad-Sommerfield) non-topological vortices in a simple Abelian model with $N=2\mathrm{}$ supersymmetry which occurs as a low energy limit of Calabi-Yau compactifications of type II superstrings. In this case the magnetic flux spreads over an arbitrarily large area. We discuss the implications for cosmology and for superstring inspired magnetic confinement scenarios.

We consider the quantum theoretical effects of a sudden change of boundary conditions which mimics the occurrence of naked singularities. For a simple demonstration, we study a massless scalar field in $\mathrm{}(1+1)\mathrm{}$-dimensional Minkowski spacetime with a finite spatial interval. We calculate the vacuum expectation value of the energy-momentum tensor and explicitly show that singular wave or thunderbolt appears along the Cauchy horizon. The thunderbolt possibly destroys the Cauchy horizon if its back reaction on the geometry is taken into account, leading to quantum restoration of the global hyperbolicity. The result of the present work may also apply to the situation where a closed string freely oscillating is traveling to a brane and changes itself to an open string pinned down by the ends, satisfying the Dirichlet boundary conditions on the brane.

The Kaluza-Klein (KK) and Randall-Sundrum (RS) theories are examined comparatively, with a focus on the behavior of the five-dimensional (Dirac) fermion in the dimensional reduction to four dimensions. They are properly treated using the Cartan formalism. In the KK case, the dual property between the electric and magnetic dipole moments is revealed in relation to the ratio of two massive parameters: the inverse of the radius of the extra-space circle and the 5D fermion mass. The order estimation of the couplings is done. In the RS case, we consider the interaction with the 5D (bulk) Higgs field and the gauge field. The chiral property, localization, and anomaly phenomena are examined. We evaluate the bulk quantum effect using the method of the induced effective action. The electric dipole moment term naturally appears. This is a new origin of $\mathrm{CP}$ violation. In the 4D limit, the dual relation between the KK model and the RS model appears.

An analysis of a spherically symmetric braneworld configuration is performed when the intrinsic curvature scalar is included in the bulk action; the vanishing of the electric part of the Weyl tensor is used as the boundary condition for the embedding of the brane in the bulk. All the solutions outside a static localized matter distribution are found; some of them are of the Schwarzschild-$\left(\mathrm{A}\right){\mathrm{dS}}_4$ form. Two modified Oppenheimer-Volkoff interior solutions are also found; one is matched to a Schwarzschild-$\left(\mathrm{A}\right){\mathrm{dS}}_4$ exterior, while the other is not. A nonuniversal gravitational constant arises, depending on the density of the considered object; however, the conventional limits of Newton’s constant are recovered. An upper bound of the order of TeV for the energy string scale is extracted from the known solar system measurements (experiments). On the contrary, in the usual brane dynamics, this string scale is calculated to be larger than TeV.

We provide an analytic method to discriminate among different types of black holes on the grounds of their strong field gravitational lensing properties. We expand the deflection angle of the photon in the neighborhood of complete capture, defining a strong field limit, in opposition to the standard weak field limit. This expansion is worked out for a completely generic spherically symmetric spacetime, without any reference to the field equations and just assuming that the light ray follows the geodesics equation. We prove that the deflection angle always diverges logarithmically when the minimum impact parameter is reached. We apply this general formalism to Schwarzschild, Reissner-Nordström, and Janis-Newman-Winicour black holes. We then compare the coefficients characterizing these metrics and find that different collapsed objects are characterized by different strong field limits. The strong field limit coefficients are directly connected to the observables, such as the position and the magnification of the relativistic images. As a concrete example, we consider the black hole at the center of our galaxy and estimate the optical resolution needed to investigate its strong field behavior through its relativistic images.

We address the production of black holes at the CERN LHC and their time evolution in space-times with compactified spacelike extra dimensions. It is shown that black holes with lifetimes of several hundred $\mathrm{fm}/c$ can be produced at LHC. The possibility of quasistable remnants is discussed.

We investigate dynamical chiral symmetry breaking in Coulomb gauge Hamiltonian QCD. Within the framework of the linked cluster expansion we extend the BCS ansatz for the vacuum and include a correlation beyond the quark-antiquark pairing. In particular we study the effects of the three-body correlations involving quark-antiquark and transverse gluons. The high momentum behavior of the resulting gap equation is discussed and a numerical computation of the chiral symmetry breaking is presented.

A model based on SO(10) grand unified theory (GUT) and supersymmetry is presented to describe phenomena observed for neutrinos. The large mixing angles among different generations, together with the small masses, are attributed to the Higgs boson structure at the GUT energy scale. Quantitative discussions of these observables are given, taking into account their energy evolution.

Gauge-invariant equal-time correlation functions are calculated in lattice QCD within the quenched approximation and with two dynamical quark species. These correlators provide information on the shape and multipole moments of the pion, the rho, the nucleon and the $\Delta .$

We argue that double logarithmic corrections ${\alpha }_s{\ln }^{2}x$ need to be resummed in the perturbative QCD factorization theorem for exclusive B meson decays, when the end-point region with a momentum fraction $\overrightarrow{x}0$ is important. These double logarithms, being of collinear origin, are absorbed into a quark jet function, which is defined by a matrix element of a quark field attached by a Wilson line. The factorization of the jet function from the decay $\overrightarrow{B}\gamma l\overline{\nu }$ is proved to all orders. Threshold resummation for the jet function leads to a universal, i.e., process-independent, Sudakov factor, whose qualitative behavior is analyzed and found to smear the end-point singularities in heavy-to-light transition form factors.

We study the charmful three-body baryonic B decays $\overline{B}\to D^{\left(*\right)}N\overline{N}:$ the color-allowed modes $B^0\to D^{\left(*\right)+}n\overline{p}$ and the color-suppressed ones $B^0\to D^{\left(*\right)0\mathrm{}}p\overline{p}.$ While the $D^{*+}{/D}^{+}$ production ratio is predicted to be of order 3, it is found that $D^{0}p\overline{p}$ has a similar rate as $D^{*0}p\overline{p}.$ It is pointed out that $B^0\to {D(D}^{*})N\overline{N}$ are dominated by the nucleon vector current or by vector meson intermediate states, whereas $B^0\to D^{0}p\overline{p}$ proceeds mainly via the exchange of the axial-vector intermediate state $a_1\mathrm{}\left(1260\right).$ The study of the $N\overline{N}$ invariant mass distribution in general indicates a threshold baryon pair production; that is, a recoil charmed meson accompanied by a low mass baryon pair except that the spectrum of $D^{0}p\overline{p}$ has a hump at large $p\overline{p}$ invariant mass $m_{p\overline{p}}\sim 3.0\mathrm{GeV}.$