Related papers: Galilean-Invariant XEFT

We analyze the recent data from the BESIII collaboration on the $X(3872)$ state in the $J/\psi\pi^+\pi^-$ and $D^0\bar{D}^0\pi^0$ decay channels. The quantum number and mass of the $X(3872)$ state allow us to exploit the universal feature…

We initiate the classification of nonrelativistic effective field theories (EFTs) for Nambu-Goldstone (NG) bosons, possessing a set of redundant, coordinate-dependent symmetries. Similarly to the relativistic case, such EFTs are natural…

In this work, we revisit the isospin violating decays of $X(3872)$ in a coupled-channel effective field theory. In the molecular scheme, the $X(3872)$ is interpreted as the bound state of $\bar{D}^{*0}D^0/\bar{D}^0D^{*0}$ and…

The radiative transitions from the neutral exotic $Z_c(4020)^0$ resonance to $X(3872)$ with emission of a photon and the pionic transitions from the charged $Z_c(4020)^\pm$ to $X(3872)$ and a charged pion $\pi^\pm$ are considered for both…

The invariant amplitudes for pion electroproduction on the nucleon are evaluated by dispersion relations at constant t with MAID as input for the imaginary parts of these amplitudes. In the threshold region these amplitudes are confronted…

Pion emitting decays and radiative ones of D^{*+,0} and D_s^{*+} are studied. As the result, the full-width of D^{*0} is predicted, by assuming the isospin symmetry. In addition, the isospin non-conserving D_s^{*+} --> D_s^+ pi^0 decay is…

If the quantum numbers of the X(3872) are J^{PC}=1^{++}, the measurement of its mass implies that it is either a loosely-bound hadronic molecule whose constituents are a superposition of the charm mesons pairs D^{*0} Dbar^0 and D^0…

The $\alpha'$-deformed frame-like Double Field Theory (DFT) is a T-duality and gauge invariant extension of DFT in which generalized Green-Schwarz transformations provide a gauge principle that fixes the higher-derivative corrections. It…

We develop an effective field theory for the description of high energetic or hard photons, the on-shell effective theory (OSEFT). The OSEFT describes the so called eikonal or semi-classical optical limit, allowing for corrections organized…

Near a critical value of the wino mass where there is a zero-energy S-wave resonance at the neutral-wino-pair threshold, low-energy winos can be described by a zero-range effective field theory (ZREFT) in which the winos interact…

We propose a method for calculating the nucleon form factors (FFs) of $G$-parity-even operators by combining Chiral Effective Field Theory ($\chi$EFT) and dispersion analysis. The FFs are expressed as dispersive integrals over the two-pion…

We study effective field theories (EFTs) enjoying (maximal) biform symmetries. These are defined by the presence of a conserved (electric) current that has the symmetries of a Young tableau with two columns of equal length. When these…

The processes $X(3872)\to D^{*0}\bar{D^{0}}+c.c.,~\gamma J/\psi,~\gamma \psi(2S),$ and $\gamma D^{+}D^{-}$ are searched for in a $9.0~\rm fb^{-1}$ data sample collected at center-of-mass energies between $4.178$ and $4.278$ GeV with the…

It is pointed out that in the decays $X(3872) \to D {\bar D} \gamma$ the possible `molecular' component of the X(3872) should give rise essentially only to a $D^0 {\bar D}^0 \gamma$ final state with a predictable spectrum, and should yield…

It is well known that in the gradient expansion approximation to density functional theory (DFT) the gradient and Laplacian of the density make interchangeable contributions to the exchange correlation (XC) energy. This is an arbitrary…

Both the mass (just below the D^{*0}Dbar^0 threshold) and the likely quantum numbers (J^{PC}=1^{++}) of the X(3872) suggest that it is either a weakly-bound hadronic ``molecule'' or a virtual state of charmed mesons. Assuming the X(3872) is…

It is pointed out that the internal structure of the narrow resonance X(3872) at the D^0 {\bar D}^{*0} threshold can be studied in some detail by measuring the rate and the spectra in the decays X(3872) \to D^0 {\bar D}^0 \pi^0 and X(3872)…

The radiative decays D^0 -> K^0(bar) P^0 gamma with nonresonant K^0(bar) P^0 (P^0 = pi^0, eta, eta') are considered within the framework which combines heavy quark effective theory and the chiral Lagrangian. Due to neutral mesons the…

Contrary to almost standard opinion that the X(3872) resonance is the D^{*0}\bar D^0+c.c. molecule or the qc\bar q\bar c four-quark state, we discuss the scenario where the X(3872)resonance is the c\bar c = \chi_{c1}(2P) charmonium which…

Dilatons, the CP-even pseudo-Nambu-Goldstone bosons arising from spontaneous scale symmetry breaking, offer a compelling alternative to axion-like particles (ALPs) yet lack a comprehensive low-energy framework. We address this by…