Nuclear Theory·nucl-th
11 papers—4 primary·7 cross-listed
Maxwell T. Hansen🇩🇪 · Stephen R. Sharpe🇺🇸
Using our recently developed relativistic three-particle quantization condition, we study the finite-volume energy shift of a spin-zero three-particle bound state. We reproduce the result obtained using non-relativistic quantum mechanics by Meissner, Rios and Rusetsky, and generalize the result to a moving frame.
Tanja Geib🇩🇪 · Alexander Merle🇩🇪 · Kai Zuber🇩🇪
We present an illustrative discussion of the physics potential of - conversion. We point out that this process, although much less frequently studied than the related but much more popular processes of - conversion and neutrinoless double beta decay, in fact is a promising alternative possibility to detect both lepton flavour and number violation. However, for this goal to be reached, a combined effort of experiments and theory, both in nuclear and particle physics, is necessary to advance. The aim of this paper is to be an "appetiser" to trigger such an initiative.
Shi-Tao Ji🇨🇳 · Xiao-Ming Xu🇨🇳 · H. J. Weber🇺🇸
A collision of a light meson and a charmonium produces quarks and antiquarks first, then the charm quark fragments into a charmed hadron, and finally three or more mesons are produced. This is the mechanism that we consider and propose to understand the prompt-J/psi nuclear modification factor in the range of J/psi transverse momentum from 10 GeV/c to 18 GeV/c, as measured by the CMS Collaboration and the ATLAS Collaboration. Unpolarized cross sections are derived and calculated for the reactions pion+charmonium ->H_c+X with H_c being a charmed meson. Numerical cross sections are parametrized and used to calculate the dissociation rate of charmonium in the interaction with pions in hadronic matter. The momentum dependence of the rate obtained is so as to lead to a decreasing charmonium nuclear modification factor with increasing transverse momentum.
Daiji Kimura🇯🇵 · Takuya Morozumi🇯🇵 · Hiroyuki Umeeda🇯🇵
Observables of light hadron decays are analyzed in a model of chiral Lagrangian which includes resonance fields of vector mesons. In particular, transition form factors are investigated for Dalitz decays of and . Moreover, the differential decay width of and the partial widths of and are also calculated. In this study, we consider a model which contains octet and singlet fields as representation of . As an extension of chiral perturbation theory, we include 1-loop ordered interaction terms. For both pseudoscalar and vector meson, we evaluate mixing matrices in which isospin/ breaking is taken into account. Furthermore, intrinsic parity violating interactions are considered with singlet fields. For parameter estimation, we carry out fittings in which a spectral function of decays, vector meson masses, decay widths of and transition form factor of are utilized as input data. Using the estimated parameter region in the model, we give predictions for decay widths and transition form factors of intrinsic parity violating decays. As further model predictions, we calculate the transition form factors of and in the vicinity of resonance regions, taking account of the contribution for intermediate and .
Jean-Marc Richard🇫🇷 · Claude Fayard🇫🇷
We study systems of three bosons bound by a long-range interaction supplemented by a short-range potential of variable strength. This generalizes the usual two-body exotic atoms where the Coulomb interaction is modified by nuclear forces at short distances. The energy shift due to the short-range part of the interaction combines two-body terms similar to the ones entering the Trueman-Deser formula, and three-body contributions. A sudden variation of the energy levels is observed near the coupling thresholds of the short-range potential. But the patterns of rearrangement are significantly modified as compared to the two-body case.
Wolfgang Lucha🇦🇹 · Dmitri Melikhov🇷🇺 · Silvano Simula🇮🇹
Compared with lattice QCD, isospin breaking of heavy-meson decay constants from QCD sum rules agrees for mesons but disagrees (by a factor of four) for mesons.
William J. Porter🇺🇸 · Joaquín E. Drut🇺🇸
Path-integral analyses originally pioneered in the study of the complex-phase problem afflicting lattice calculations of finite-density quantum chromodynamics are generalized to non-relativistic Fermi gases with repulsive interactions. Using arguments similar to those previously applied to relativistic theories, we show that the analogous problem in nonrelativistic systems manifests itself naturally in Tan's contact as a nontrivial cancellation between terms with varied dependence on extensive thermodynamic quantities. We analyze that case under the assumption of gaussian phase distribution, which is supported by our Monte Carlo calculations and perturbative considerations. We further generalize these results to observables other than the contact, as well as to polarized systems and systems with fixed particle number. Our results are quite general in that they apply to repulsive multi-component fermions, are independent of dimensionality or trapping potential, and hold in the ground state as well as at finite temperature.
first authorsco-authorsvia INSPIRE