We show that the transverse double spin asymmetry in the Drell-Yan process contributed only from the Sivers functions can be picked out by the weighting function $\frac{Q_T}{M^2}(\cos (\varphi -{\varphi }_{S_1})\cos (\varphi -{\varphi }_{S_2})+3\sin (\varphi -{\varphi }_{S_1})\sin (\varphi -{\varphi }_{S_2}))$. The asymmetry is proportional to the product of two Sivers functions from each hadron $f_{1T}^{\perp (1)}\times f_{1T}^{\perp (1)}$. Using two sets of Sivers functions extracted from the semi-inclusive deeply elastic scattering data at HERMES, we estimate this asymmetry in the $p^{\uparrow }{\overline{p}}^{\uparrow }$ Drell-Yan process which is possible to be performed in high energy storage ring at GSI. The prediction of double spin asymmetry in the Drell-Yan process contributed by the function $g_{1T}(x,{\mathbf{k}}_T^2)$, which can be extracted by the weighting function $\frac{Q_T}{M^2}(3\cos (\varphi -{\varphi }_{S_1})\cos (\varphi -{\varphi }_{S_2})+\sin (\varphi -{\varphi }_{S_1})\sin (\varphi -{\varphi }_{S_2}))$, is also given at GSI.

We investigate the kaon semileptonic decay ($K_{l3}$) form factors within the framework of the nonlocal chiral quark model ($\chi \mathrm{QM}$) from the instanton vacuum, taking into account the effects of flavor SU(3) symmetry breaking. We also consider the problem of gauge invariance arising from the momentum-dependent quark mass in the present work. All theoretical calculations are carried out without any adjustable parameter, the average instanton size ($\rho \sim 1/3\mathrm{fm}$) and the interinstanton distance ($R\sim 1\mathrm{fm}$) having been fixed. We also show that the present results satisfy the Callan-Treiman low-energy theorem as well as the Ademollo-Gatto theorem. Using the $K_{l3}$ form factors, we evaluate relevant physical quantities. It turns out that the effects of flavor SU(3) symmetry breaking are essential in reproducing the kaon semileptonic form factors. The present results are in good agreement with experiments, and are compatible with other model calculations.

We analyze the rare and flavor-changing decay of the top quark into a charm quark and a gauge boson in the littlest Higgs model with $T$ parity (LHT). We calculate the one-loop level contributions from the $T$ parity odd mirror quarks and gauge bosons. We find that the decay $t\to cV$, $(V=g,\gamma ,Z)$ in the LHT model can be significantly enhanced relative to those in the standard model. Our numerical results show that the top quark flavor-changing neutral current decay can be as large as $\mathrm{Br}(t\to cg)\sim {10}^{-2}$, $\mathrm{Br}(t\to cZ)\sim {10}^{-5}$, and $\mathrm{Br}(t\to c\gamma )\sim {10}^{-7}$ in the favorite parameter space in the LHT model.

A measurement of the top quark mass using events with one charged lepton, missing transverse energy, and jets in the final state, collected by the D0 detector from $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ at the Fermilab Tevatron collider, is presented. A constrained fit is used to fully reconstruct the kinematics of the events. For every event a top quark mass likelihood is calculated taking into account all possible jet assignments and the probability that an event is signal or background. Lifetime-based identification of $b$ jets is employed to enhance the separation between $t\overline{t}$ signal and background from other physics processes and to improve the assignment of the observed jets to the quarks in the $t\overline{t}$ hypothesis. We extract a multiplicative jet energy scale (JES) factor in situ, greatly reducing the systematic effect related to the jet energy measurement. In a data sample with an integrated luminosity of $425{\mathrm{pb}}^{-1}$, we observe 230 candidate events, with an estimated background of 123 events, and measure $m_t=173.7\pm 4.4(\mathrm{stat}+\mathrm{JES}{)}_{-2.0}^{+2.1}(\mathrm{syst})\mathrm{GeV}$. This result represents the first application of the ideogram technique to the measurement of the top quark mass in lepton+jets events.

In the first part of this paper, we extend the $d$-dimensional unitarity cut method of Anastasiou et al. to cases with massive propagators. We present formulas for integral reduction with which one can obtain coefficients of all pentagon, box, triangle and massive bubble integrals. In the second part of this paper, we present a detailed study of the phase space integration for unitarity cuts. We carry out spinor integration in generality and give algebraic expressions for coefficients, intended for automated evaluation.

We investigate the properties of multiparticle states in deformed special relativity (DSR). Starting from the Lagrangian formalism with an energy dependent metric, the conserved Noether current can be derived which is additive in the usual way. The integrated Noether current had previously been discarded as a conserved quantity, because it was correctly realized that it does no longer obey the DSR transformations. We identify the reason for this mismatch in the fact that DSR depends only on the extensive quantity of total four momentum instead of the energy-momentum densities as would be appropriate for a field theory. We argue that the reason for the failure of DSR to reproduce the standard transformation behavior in the well established limits is due to the missing sensitivity to the volume inside which energy is accumulated. We show that the soccer-ball problem is absent if one formulates DSR instead for the field densities. As a consequence, estimates for predicted effects have to be corrected by many orders of magnitude. Further, we derive that the modified quantum field theory implies a locality bound.

In this paper we use the conformal properties of the spinor field to show how we can obtain the fermion quasinormal modes for a higher-dimensional Schwarzschild black hole. These modes are of interest in so-called split fermion models, where quarks and leptons are required to exist on different branes in order to keep the proton stable. As has been previously shown, for brane-localized fields, the larger the number of dimensions the faster the black hole damping rate. Moreover, we also present the analytic forms of the quasinormal frequencies in both the large angular momentum and the large mode number limits.

We classify the cosmological behaviors of the domain wall under junctions between two spacetimes in terms of various parameters: cosmological constants of bulk spacetime, a tension of a domain wall, and mass parameters of the black-hole–type metric. Especially, we consider the false-true vacuum-type junctions and the domain wall connecting between an inner AdS space and an outer AdS Reissner-Nordström black hole. We find that there exists a solution to the junction equations with multiple accelerations.

Flavor-dependent long range (LR) leptonic forces, like those mediated by the $L_e-L_{\mu }$ or $L_e-L_{\tau }$ gauge bosons, constitute a minimal extension of the standard model that preserves its renormalizability. We study the impact of such interactions on the solar neutrino oscillations when the interaction range $R_{\mathrm{LR}}$ is much larger than the Earth-Sun distance. The LR potential can dominate over the standard charged current potential inside the Sun in spite of strong constraints on the coupling $\alpha$ of the LR force coming from the atmospheric neutrino data and laboratory search for new forces. We demonstrate that the solar and atmospheric neutrino mass scales do not get trivially decoupled even if ${\theta }_{13}$ is vanishingly small. In addition, for $\alpha \gtrsim {10}^{-52}$ and normal hierarchy, resonant enhancement of ${\theta }_{13}$ results in nontrivial energy dependent effects on the ${\nu }_e$ survival probability. We perform a complete three generation analysis, and obtain constraints on $\alpha$ through a global fit to the solar neutrino and KamLAND data. We get the $3\sigma$ limits ${\alpha }_{e\mu }<3.4\times {10}^{-53}$ and ${\alpha }_{e\tau }<2.5\times {10}^{-53}$ when $R_{\mathrm{LR}}$ is much smaller than our distance from the galactic center. With larger $R_{\mathrm{LR}}$, the collective LR potential due to all the electrons in the galaxy becomes significant and the constraints on $\alpha$ become stronger by up to two orders of magnitude.

The renormalized mean value of the corresponding components of the energy-momentum tensor for massive scalar fields coupled to an arbitrary gravitational field configuration having cylindrical symmetry are analytically evaluated using the Schwinger-DeWitt approximation, up to second order in the inverse mass value. The general results are employed to explicitly derive compact analytical expressions for the energy-momentum tensor in the particular background of the black-string space-time. In the case of the black string considered in this work, we prove that a violation of the weak energy condition occurs at the horizon of the space-time for values of the coupling constant, which include as particular cases the most interesting of minimal and conformal coupling.

A baryogenesis scenario in supersymmetric standard models with Dirac neutrinos proposed by Abel and Page is reconsidered, introducing intermediate scale physics to stabilize the runaway potential along a right-handed sneutrino direction. Contrary to previous results, the baryon number asymmetry can be explained even for higher reheating temperature without entropy production if the lightest neutrino mass is small and/or thermal effects induce early oscillation. We also discuss the solution to the problem of dark matter overproduction from the right-handed sneutrino decay by $\mathrm{SU}(2{)}_R$ gauge interaction.

Fragmentation functions and their uncertainties are determined for pion, kaon, and proton by a global ${\chi }^2$ analysis of charged-hadron production data in electron-positron annihilation and by the Hessian method for error estimation. It is especially important that the uncertainties of the fragmentation functions are estimated in this analysis. The results indicate that the fragmentation functions, especially gluon and light-quark fragmentation functions, have large uncertainties at small $Q^2$. There are large differences between widely used functions by Kniehl, Kramer, and Pötter (KKP) and Kretzer; however, they are compatible with each other and also with our functions if the uncertainties are taken into account. We find that determination of the fragmentation functions is improved in next-to-leading order (NLO) analyses for the pion and kaon in comparison with leading-order ones. Such a NLO improvement is not obvious in the proton. Since the uncertainties are large at small $Q^2$, the uncertainty estimation is very important for analyzing hadron-production data at small $Q^2$ or $p_T$ ($Q^2$, $p_T^2\ll M_Z^2$) in lepton scattering and hadron-hadron collisions. A code is available for general users for calculating obtained fragmentation functions.

We propose a new method for obtaining the $CP$ phase $\alpha$, based on measurements of $B_d^0\to K^0{\overline{K}}^0$, along with theoretical input. Because of the similarities of QCD factorization (QCDf) and perturbative QCD (pQCD), this input is basically the same for each of these models. Although the theoretical error is large at present, many of the contributing quantities will be better known in the future, leading to a smaller error. One outstanding question is the extent to which the precision on quark masses, especially $m_c/m_b$, can be improved. If one assumes that new physics is not present, the method can be used to predict the values of $CP$ asymmetries in $B_d^0\to K^0{\overline{K}}^0$: $0.02\le A_{\mathrm{dir}}^2+A_{\mathrm{mix}}^2\le 0.125$. A result outside this range would signal the existence of long-distance effects beyond those included in models of nonleptonic decays based on factorization (such as QCDf and pQCD), or the presence of new physics.

New generalization of the $z$-scaling in inclusive particle production is proposed. The scaling variable $z$ is a fractal measure which depends on kinematic characteristics of the underlying subprocess expressed in terms of the momentum fractions $x_1$ and $x_2$ of the incoming protons. In the generalized approach, $x_1$ and $x_2$ are functions of the momentum fractions $y_a$ and $y_b$ of the scattered and recoil constituents carried by the inclusive particle and recoil object, respectively. The scaling function $\psi (z)$ for charged and identified hadrons produced in proton-proton collisions is constructed. The fractal dimensions and heat capacity of the produced medium entering definition of the variable $z$ are established to restore energy, angular, and multiplicity independence of $\psi (z)$. The proposed scheme allows a unique description of data on inclusive cross sections at high energies. Universality of the shape of the scaling function for various types of produced hadrons ($\pi$, $K$, $\overline{p}$, $\Lambda$) is shown. Results of the analysis of experimental data are compared with the next-to-leading order (NLO) QCD calculations in $p_T$ and $z$-presentations. The obtained results suggest that the $z$-scaling may be used as a tool for searching for new physics phenomena of particle production in high transverse momentum and the high multiplicity region at proton-proton colliders RHIC and LHC.

In the heavy quark and large $N_c$ limits, ordinary (exotic) heavy baryons can be considered as bound states of heavy mesons (antimesons) and chiral solitons. In these limits, the heavy mesons (or antimesons) and the chiral solitons are extremely heavy and are presumed to fall to the bottom of the effective potential. Previous studies have approximated the effective potential as harmonic about the minimum. However, when realistic masses for the heavy meson and chiral soliton are considered, longer range parts of the effective potential can become relevant. In this paper, we show that these longer-ranged effects yield effective wave functions which are qualitatively very different from those expected from the combined large $N_c$ and heavy quark limits. These potentials can support bound heavy pentaquarks under some conditions. The consequence of these new energy states and wave functions on the Isgur-Wise function for the semileptonic decay of heavy baryons is also considered.

In the present work, we quantize a closed Friedmann-Robertson-Walker model in the presence of a positive cosmological constant and radiation. It gives rise to a Wheeler-DeWitt equation for the scale factor which has the form of a Schrödinger equation for a potential with a barrier. We solve it numerically and determine the tunneling probability for the birth of a asymptotically DeSitter, inflationary universe, initially, as a function of the mean energy of the initial wave function. Then, we verify that the tunneling probability increases with the cosmological constant, for a fixed value of the mean energy of the initial wave function. Our treatment of the problem is more general than previous ones, based on the WKB approximation. That is the case because we take into account the fact that the scale factor ($a$) cannot be smaller than zero. It means that, one has to introduce an infinity potential wall at $a=0$, which forces any wave packet to be zero there. That condition introduces new results, in comparison with previous works.

Analytical calculations of extragalactic cosmic ray spectra above $\sim {10}^{17}\mathrm{eV}$ are often performed assuming continuous source distributions, giving rise to spectra that depend little on the propagation mode, be it rectilinear or diffusive. We perform trajectory simulations for proton primaries in the probably more realistic case of discrete sources with a density of $\sim {10}^{-5}{\mathrm{Mpc}}^{-3}$. We find two considerable nonuniversal effects that depend on source distributions and magnetic fields: First, the primary extragalactic cosmic ray flux can become strongly suppressed below a few ${10}^{18}\mathrm{eV}$ due to partial confinement in magnetic fields surrounding sources. Second, the secondary photon to primary cosmic ray flux ratio between $\simeq 3\times {10}^{18}\mathrm{eV}$ and $\simeq {10}^{20}\mathrm{eV}$ decreases with decreasing source density and increasing magnetization. As a consequence, in acceleration scenarios for the origin of highest energy cosmic rays the fraction of secondary photons may be difficult to detect even for experiments such as Pierre Auger. The cosmogenic neutrino flux does not significantly depend on source density and magnetization.

We report the first systematic analysis of the off-light-cone effects in sum rules for heavy-to-light form factors. These effects are investigated in a model based on scalar constituents, which allows a technically rather simple analysis but has the essential features of the analogous QCD calculation. The correlator relevant for the extraction of the heavy-to-light form factor is calculated in two different ways: first, by adopting the full Bethe-Salpeter amplitude of the light meson and, second, by performing the expansion of this amplitude near the light cone $x^2=0$. We demonstrate that the contributions to the correlator from the light-cone term $x^2=0$ and the off-light-cone terms $x^2\ne 0$ have the same order in the $1/m_Q$ expansion. The light-cone correlator, corresponding to $x^2=0$, is shown to systematically overestimate the full correlator, the difference being $\sim {\Lambda }_{\mathrm{QCD}}/\delta$, with $\delta$ the continuum subtraction parameter of order 1 GeV. Numerically, this difference is found to be $10÷20\%$.

We analyze the spin structure of inclusive semileptonic $b\to c$ transitions and the effects of non-standard model couplings on the rates and the spectra. The calculation includes the $\mathcal{O}({\alpha }_s)$ corrections as well as the leading nonperturbative ones.