International Journal of Modern Physics A

We provide a comprehensive and pedagogical introduction to the MADANALYSIS 5 framework, with a particular focus on its usage for reinterpretation studies. To this end, we first review the main features of the normal mode of the program and how a detector simulation can be handled. We then detail, step-by-step, how to implement and validate an existing LHC analysis in the MADANALYSIS 5 framework and how to use this reimplementation, possibly together with other recast codes available from the MADANALYSIS 5 Public Analysis Database, for reinterpreting ATLAS and CMS searches in the context of a new model. Each of these points is illustrated by concrete examples. Moreover, complete reference cards for the normal and expert modes of MADANALYSIS 5 are provided in two technical appendices.

Like the two-photon and two-gluon decays of the $P$-wave ${\chi }_{c0,2}$ and ${\chi }_{b0,2}$ charmonium state for which the Born term produces a very simple decays amplitude in terms of an effective Lagrangian with two-quark local operator, the Born term for the processes $c\bar{d}\to (\pi ,K)\ell \nu$ and $b\bar{d}\to (\pi ,K)\ell \nu$, could also produce the $D$ and $B$ meson semileptonic decays with the light meson $\pi$, $K$ in the final state. In this approach to heavy-light meson form factors with the $\pi$, $K$ meson treated as Goldstone boson, a simple expression is found for the decays form factors, given as: $f_{+}(0)/\left(\right.1-q^2/\left(\right.m_H^2+m_{\pi }^2\left)\right.\left)\right.$, with $H=D$, $B$ for $D$, $B\to \pi$ form factors, and $f_{+}(0)/\left(\right.1-q^2/\left(\right.m_H^2+m_K^2\left)\right.\left)\right.$ for $B$, $D\to K$ form factor. The purpose of this paper is to show that this expression for the form factors could describe rather well the $q^2$-behavior observed in the BaBar, Belle and BESIII measurements and lattice simulation. In particular, the $D\to K$ form factors are in good agreement with the measured values in the whole range of $q^2$ showing evidence for $SU(3)$ breaking with the presence of $m_K^2$ term in the quark propagator, but some corrections to the Born term are needed at large $q^2$ for $D$, $B\to \pi$ form factors.

The ${𝒩}=1$ super-Yang–Mills theory in the presence of the local composite operator $A^2$ is analyzed in the Wess–Zumino gauge by employing the Landau gauge fixing condition. Due to the supersymmetric structure of the theory, two more composite operators, $A_{\mu }{\gamma }_{\mu }\lambda$ and $\bar{\lambda }\lambda$, related to the SUSY variations of $A^2$ are also introduced. A BRST invariant action containing all these operators is obtained. An all-order proof of the multiplicative renormalizability of the resulting theory is then provided by means of the algebraic renormalization setup. Though, due to the nonlinear realization of the supersymmetry in the Wess–Zumino gauge, the renormalization factor of the gauge field turns out to be different from that of the gluino.

The interest in higher derivatives field theories has its origin mainly in their influence concerning the renormalization properties of physical models and to remove ultraviolet divergences. The noncommutative Podolsky theory is a constrained system that cannot be directly quantized by the canonical way. In this work, we have used the Faddeev–Jackiw method in order to obtain the Dirac brackets of the NC space–time Maxwell, Proca and Podolsky theories.

In this work, we study the dynamics of particles coupled to a dissipative environment from Bohmian trajectory perspective. The dissipation is modeled using the concept of memory-dependent derivative (MDD), which is characterized by its time-delay constant $\tau$ and nonsingular kernel $K(x,t)$ of two parameters $a$, $b$. By assuming a Gaussian packet wave function, we derived a MDD-Langevin equation (MDDLE). The general behavioral solution $x_c(t)$ of the MDDLE is investigated for the case of Gaussian fluctuation force. Based on the miscellaneous choices of $a$, $b$, $\tau$, the findings are that $x_c(t)$ can exhibit distinct behaviors, such as monotonic and nonmonotonic decay without zero crossings, oscillatory-like without zero and with zero crossing. Therefore, we have either diffusion or oscillatory dominate based on the problem parameters. For a harmonically bound heavy quarkonium, characterized by the angular frequency $\omega$, the position correlation function $C_x(t)$ is then obtained and analyzed numerically. The analysis shows that this correlation function is also sensitive to the various choices of $\tau$ and kernel parameters. Based on these choices, the correlation function exhibits distinct behaviors: oscillation without damping, damping, and enhanced. This wide range of behavior coverage increases the versatility to fit nonlinear or memory-dependent experimental findings. The results are compared with the fractional Langevin equation.

We investigate the breaking of Lorentz symmetry caused by the inclusion of an external four-vector via a Chern–Simons-like term in the Duffin–Kemmer–Petiau Lagrangian for massless and massive spin-one fields. The resulting equations of motion lead to the appearance of birefringence, where the corresponding photons are split into two propagation modes. We discuss the gauge invariance of the extended Lagrangian. Throughout the paper, we utilize projection operators to reduce the wave functions to their physical components, and we provide many new properties of these projection operators.

The higher-twist (HT) contribution to the charged-kaon pair production in the high energy proton–antiproton collisions at large transverse momentum $p_T$ is investigated by using the frozen coupling constant approach for various kaon distribution amplitudes (DAs), which are predicted by light-cone formalism, the light-front quark model, the nonlocal chiral quark model and the light-front holographic AdS/CFT approach. In the numerics, the dependencies of the HT contribution on the transverse momentum $p_T$, the rapidity $y$, and the variable $x_T$ are discussed with special emphasis put on DAs. The HT contribution is also compared with the leading-twist ones. It is shown that the HT contributions are dependent on the kaon DAs and also some other phenomenological parameters such as momentum cutoff parameter $\mathrm{\Delta }p$. Inclusive kaon pair production presents a remarkable test case in which HT terms dominate those of LT in certain kinematic regions. The HT direct production process via gluon–gluon fusion contributes significantly to the inclusive cross-section at large $p_T$.