A generalized twistor transform for spinning particles in $3+1$ dimensions is constructed that beautifully unifies many types of spinning systems by mapping them to the same twistor $Z_A=\left(\begin{array}{c}{\mu }^{\dot{\alpha }}\\ {\lambda }_{\alpha }\end{array}\right)$, thus predicting an infinite set of duality relations among spinning systems with different Hamiltonians. Usual 1T-physics is not equipped to explain the duality relationships and unification between these systems. We use 2T-physics in $4+2$ dimensions to uncover new properties of twistors, and expect that our approach will prove to be useful for practical applications as well as for a deeper understanding of fundamental physics. Unexpected structures for a new description of spinning particles emerge. A unifying symmetry SU(2, 3) that includes conformal symmetry $\mathrm{SU}(2,2)=\mathrm{SO}(4,2)$ in the massless case turns out to be a fundamental property underlying the dualities of a large set of spinning systems, including those that occur in high spin theories. This may lead to new forms of string theory backgrounds as well as to new methods for studying various corners of $M$ theory. In this paper we present the main concepts, and in a companion paper we give other details.

This paper discusses the minimal quiver gauge theory embedding of the standard model that could arise from brane world type string theory constructions. It is based on the low energy effective field theory of D branes in the perturbative regime. The model differs from the standard model by the addition of one extra massive gauge boson, and contains only one additional parameter to the standard model: the mass of this new particle. The coupling of this new particle to the standard model is uniquely determined by input from the standard model and consistency conditions of perturbative string theory. We also study some aspects of the phenomenology of this model and bounds on its possible observation at the Large Hadron Collider.

We study, in the framework of open systems, the entanglement generation of two independent uniformly accelerated atoms in interaction with the vacuum fluctuations of massless scalar fields subjected to a reflecting plane boundary. We demonstrate that, with the presence of the boundary, the accelerated atoms exhibit distinct features from static ones in a thermal bath at the corresponding Unruh temperature in terms of the entanglement creation at the neighborhood of the initial time. In this sense, accelerated atoms in vacuum do not necessarily have to behave as if they were static in a thermal bath at the Unruh temperature.

Baryon acoustic oscillations (BAO) have recently been observed in the distribution of distant galaxies. The height and location of the BAO peak are strong discriminators of cosmological parameters. Here we consider the ways in which weak gravitational lensing distorts the BAO signal. We find two effects that can affect the height of the BAO peak in the correlation function at the percent level but that do not significantly impact the position of the peak and the measurement of the sound horizon. BAO turn out to be robust cosmological standard rulers.

The exclusive processes $e^{+}{e}^{-}\to VP$, in the region of which the final state meson momentum is much larger than the hadronic scale ${\Lambda }_{\mathrm{QCD}}$, are studied in the framework of the perturbative quantum chromodynamics (PQCD) approach based on the $k_T$ factorization. Including the transverse momentum distribution in the light-cone wave functions, our results are consistent with the experimental measurements. According to our results, many processes have large enough cross sections to be detected at $\sqrt{s}=10.58\mathrm{GeV}$. The $s$ dependence of the cross section has been directly studied and our result indicates that the $1/s^3$ scaling is more favored than $1/s^4$. We also find that the gluonic contribution for the processes involving ${\eta }^{{(}^{\prime })}$ is tiny.

We report on measurements of the inclusive jet production cross section as a function of the jet transverse momentum in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$, using the $k_{\mathrm{T}}$ algorithm and a data sample corresponding to $1.0{\mathrm{fb}}^{-1}$ collected with the Collider Detector at Fermilab in run II. The measurements are carried out in five different jet rapidity regions with $|y^{\mathrm{jet}}|<2.1$ and transverse momentum in the range $54<p_{\mathrm{T}}^{\mathrm{jet}}<700\mathrm{GeV}/c$. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.

The phase diagram of the massive chiral Gross-Neveu model (the $1+1$-dimensional Nambu-Jona-Lasinio model at large $N$) is investigated in the vicinity of the tricritical point. Using the derivative expansion, the grand canonical potential is cast into the form of a Ginzburg-Landau effective action. Minimization of this action by variational and numerical methods reveals both 1st and 2nd order phase transitions to a chiral crystal phase, separated by a tricritical line. These findings are contrasted to the massive Gross-Neveu model with discrete chiral symmetry where only 2nd order transitions have been observed.

We study linearized gravity in a six-dimensional Einstein-Maxwell model of warped braneworlds, where the extra dimensions are compactified by a magnetic flux. It is difficult to construct a strict codimension two braneworld with matter sources other than pure tension. To overcome this problem we replace the codimension two defect by an extended brane, with one spatial dimension compactified on a Kaluza-Klein circle. Our background is composed of a warped, axisymmetric bulk and one or two branes. We find that weak gravity sourced by arbitrary matter on the brane(s) is described by a four-dimensional scalar-tensor theory. We show, however, that the scalar mode is suppressed at long distances and hence four-dimensional Einstein gravity is reproduced on the brane.

We consider the possibility of extracting the CKM angle $\gamma$ with $B_c$ decays. The modes $B_c^{\pm }\to (D^0)D_s^{\pm }\to (K^{*+}{K}^{-})D_s^{\pm }$ and $B_c^{\pm }\to ({\overline{D}}^0)D_s^{\pm }\to (K^{*+}{K}^{-})D_s^{\pm }$ are found to be well suited for the extraction of $\gamma$. Since a large number of $B_c$ mesons are expected to be produced at the Large Hadron Collider, it would be very interesting to explore the determination of $\gamma$ with these modes.

An investigation of the production of particles in a slowly varying but extremely intense magnetic field is extended to the case of axions. The motivation is, as for some previously considered cases, the possibility that such kind of magnetic field may exist around very compact astrophysical objects.

The BEC-BCS (Bose-Einstein condensation–Bardeen-Cooper-Shriffer) crossover in QCD at finite baryon and isospin chemical potentials is investigated in the Nambu-Jona-Lasinio model. The diquark condensation in two color QCD and the pion condensation in real QCD would undergo a BEC-BCS crossover when the corresponding chemical potential increases. We determined the crossover chemical potential as well as the BEC and BCS regions. The crossover is not triggered by increasing the strength of attractive interaction among quarks but driven by changing the charge density. The chiral symmetry restoration at finite temperature and density plays an important role in the BEC-BCS crossover. For real QCD, strong couplings in diquark and vector meson channels can induce a diquark BEC-BCS crossover in color superconductor, and in the BEC region the chromomagnetic instability is fully cured and the ground state is a uniform phase.

We investigate the BCS-BEC (Bardeen-Cooper-Shriffer—Bose-Einstein condensation) crossover at zero temperature in the frame of a relativistic model. The universality of the BCS-BEC crossover for nonrelativistic systems breaks down in the relativistic case and the crossover can be induced by changing the density. When the effective scattering length is much less than the fermion Compton wavelength, we recover the nonrelativistic result if the gas is initially in a nonrelativistic state. At ultrastrong coupling where the scattering length is of the order of the Compton wavelength, a new BEC state appears. In this state the condensed bosons become nearly massless and antifermions are excited. The behavior of the Goldstone mode and the mixing between the amplitude and phase modes are significantly different in different condensed regions.

We report measurements of branching fractions and $CP$ asymmetries for $B\to \eta K^{*}$ and $B\to \eta \rho$ decays. These results are obtained from a $414{\mathrm{fb}}^{-1}$ data sample collected at the ${\rm Y}(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. We measure the following branching fractions: $\mathcal{B}(B^0\to \eta K^{*0})=(15.2\pm 1.2\pm 1.0)\times {10}^{-6}$ and $\mathcal{B}(B^{+}\to \eta K^{*+})=({19.3}_{-1.9}^{+2.0}\pm 1.5)\times {10}^{-6}$, where the first error is statistical and the second systematic. We also find a $2.7\sigma$ excess in the $B^{+}\to \eta {\rho }^{+}$ mode and measure $\mathcal{B}(B^{+}\to \eta {\rho }^{+})=({4.1}_{-1.3}^{+1.4}\pm 0.4)\times {10}^{-6}<6.5\times {10}^{-6}$ at 90% confidence level. For $B^0\to \eta {\rho }^0$ decays, we determine the upper limit $\mathcal{B}(B^0\to \eta {\rho }^0)<1.9\times {10}^{-6}$ at 90% confidence level. The partial rate asymmetries are ${\mathcal{A}}_{CP}(\eta K^{*0})=0.17\pm 0.08\pm 0.01$, ${\mathcal{A}}_{CP}(\eta K^{*+})=0.03\pm 0.10\pm 0.01$, and ${\mathcal{A}}_{CP}(\eta {\rho }^{+})=-{0.04}_{-0.32}^{+0.34}\pm 0.01$.

We analyze the algebra of Dirac observables of the relativistic particle in four space-time dimensions. We show that the position observables become noncommutative and the commutation relations lead to a structure very similar to the noncommutative geometry of deformed special relativity (DSR). In this framework, it appears natural to consider the 4D relativistic particle as a five-dimensional massless particle. We study its quantization in terms of wave functions on the 5D light cone. We introduce the corresponding five-dimensional action principle and analyze how it reproduces the physics of the 4D relativistic particle. The formalism is naturally subject to divergences (due to the 5D representation), and we show that DSR arises as a natural regularization: the 5D light cone is regularized as the de Sitter space. We interpret the fifth coordinate as the particle’s proper time while the fifth moment can be understood as the mass. Finally, we show how to formulate the Feynman propagator and the Feynman amplitudes of quantum field theory in this context in terms of Dirac observables. This provides new insights for the construction of observables and scattering amplitudes in DSR.

We present results of a Monte Carlo simulation of the three dimensional Thirring model with the number of fermion flavors $N_f$ varied between 2 and 18. By identifying the lattice coupling at which the chiral condensate peaks, simulations are performed at couplings $g^2(N_f)$ corresponding to the strong coupling limit of the continuum theory. The chiral symmetry restoring phase transition is studied as $N_f$ is increased, and the critical number of flavors estimated as $N_{fc}=6.6(1)$. The critical exponents measured at the transition do not agree with self-consistent solutions of the Schwinger-Dyson equations; in particular, there is no evidence for the transition being of infinite order. Implications for the critical flavor number in ${\mathrm{QED}}_3$ are briefly discussed.

Most recently, both BABAR and Belle experiments found evidences of neutral $D$ mixing. In this paper, we discuss the constraints on the strong phase difference in $D^0\to K\pi$ decay from the measurements of the mixing parameters, $y^{\prime }$, $y_{CP}$, and $x$ at the $B$ factories. With $CP$ tag technique at $\psi (3770)$ peak, the extraction of the strong phase difference at BES-III is discussed. The sensitivity of the measurement of the mixing parameter $y$ is estimated in BES-III experiment at $\psi (3770)$ peak. Finally, we also make an estimate on the measurements of the mixing rate $R_M$.

In $\chi \mathrm{QM}$, a quark can emit Goldstone bosons. The flavor symmetry breaking in the Goldstone boson emission process is used to interpret the nucleon flavor-spin structure. In this paper, we study the inner structure of constituent quarks implied in $\chi \mathrm{QM}$ caused by the Goldstone boson emission process in nucleon. From a simplified model Hamiltonian derived from $\chi \mathrm{QM}$, the intrinsic wave functions of constituent quarks are determined. Then the obtained transition probabilities of the emission of Goldstone boson from a quark can give a reasonable interpretation to the flavor symmetry breaking in nucleon flavor-spin structure.

Using the Abelian Higgs model, we study the radial excitations of single vortex and their propagation modes along the vortex line. We call such beyond-stringy modes peristaltic modes of single vortex. With the profile of the static vortex, we derive the vortex-induced potential, i.e., single-particle potential for the Higgs and the photon field fluctuations around the static vortex, and investigate the coherently propagating fluctuations which correspond to the vibration of the vortex. We derive, analyze, and numerically solve the field equations of the Higgs and the photon field fluctuations around the static vortex with various Ginzburg-Landau parameter $\kappa$ and topological charge $n$. Around the Bogomol’nyi-Prasad-Sommerfield value or critical coupling ${\kappa }^2=1/2$, there appears a significant correlation between the Higgs and the photon field fluctuations mediated by the static vortex. As a result, for ${\kappa }^2=1/2$, we find the characteristic new-type discrete pole of the peristaltic mode corresponding to the quasibound state of coherently fluctuating fields and the static vortex. We investigate its excitation energy, correlation energy of coherent fluctuations, spatial distributions, and the resulting magnetic flux behavior in detail. Our investigation covers not only usual type-II vortices with $n=1$ but also type-I and type-II vortices with $n\in Z$ for the application to various general systems where the vortexlike objects behave as the essential degrees of freedom.