Nuclear Theory·nucl-th

Thursday·July 8, 2021

10 papers—5 primary·5 cross-listed

06
Thermal monopole condensation in QCD with physical quark masses
Marco Cardinali🇮🇹 · Massimo D'Elia🇮🇹 · Andrea Pasqui🇮🇹
Thermal monopoles, identified after Abelian projection as magnetic currents wrapping non-trivially around the thermal circle, are studied in $N_{f} = 2 + 1$ QCD at the physical point. The distribution in the number of wrappings, which in pure gauge theories points to a condensation temperature coinciding with deconfinement, points in this case to around 275 MeV, almost twice the QCD crossover temperature $T_{c}$ ; similar indications emerge looking for the formation of a percolating current cluster. The possible relation with other non-perturbative phenomena observed above $T_{c}$ is discussed.
↳ hep-lathep-phhep-thnucl-th17 citations
07
Interpretation of neutral charm mesons near threshold as unparticles
Eric Braaten🇺🇸 · Hans-Werner Hammer🇩🇪
The existence of the $X (3872)$ resonance extremely close to the $D^{* 0} D ˉ^{0}$ threshold implies that neutral charm mesons have an approximate nonrelativistic conformal symmetry. Systems consisting of these mesons with small kinetic energies produced in a short-distance reaction are unparticles in the sense that they can be created by operators with definite scaling dimensions in a nonrelativistic conformal field theory. There is a scaling region in which their energy distribution has power-law behavior with an exponent determined by the scaling dimension of the operator. The unparticle associated with two neutral charm mesons produces a peak in the recoil momentum spectrum of $K^{\pm}$ in inclusive decays of $B^{\pm}$ that has been observed. The scaling dimensions of the unparticles associated with three neutral charm mesons are calculated. They can be determined experimentally by measuring the invariant mass distributions for $X D^{0}$ or $X D^{* 0}$ in inclusive prompt production at the Large Hadron Collider.
↳ hep-phnucl-thPRL(2022)·14 citations
08
Spin contribution to the dissociation of bound states in rotating medium in magnetic field
Kirill Tuchin🇺🇸
Magneto-rotational dissociation is the decay, by the way of tunneling, of a rotating bound state in the magnetic field. The corresponding probability was recently computed in the quasi-classical approximation using the Imaginary Time Method and was shown to increase with the angular velocity and decrease with the magnetic field strength \cite{Tuchin:2021lxl}. This letter reports the calculation of the quantum correction to the dissociation probability associated with the spin of the tunneling particle. The quasi-classical motion of spin is described by the Bargmann--Michel--Telegdi equation in the rotating frame. It is shown that the spin contribution significantly increases the dissociation probability. Applications to the Quark-Gluon Plasma are touched upon.
↳ hep-phnucl-thNPA(2021)·5 citations
09
Remarks on non-perturbative three--body dynamics and its application to the $K K K ˉ$ system
Xu Zhang🇩🇪 · Christoph Hanhart🇩🇪 · Ulf-G. Meißner🇩🇪 · Ju-Jun Xie🇨🇳
A formalism is discussed that allows for a straightforward treatment of the relativistic three-body problem while keeping the correct analytic structure. In particular it is demonstrated that sacrificing covariance for analyticity can be justified by the hierarchy of different contributions in the spirit of an effective field theory. For definiteness the formalism is applied to the $K K K ˉ$ system allowing for the emergence of the $a_{0} (980)$ and the $f_{0} (980)$ as hadronic molecules. For simplicity all inelastic channels are switched off.
↳ hep-phhep-exnucl-thEPJA(2022)·22 citations
10
Using spin alignment of inelastically-excited fast beams to make spin assignments: the spectroscopy of 13O as a test case
R.J. Charity🇺🇸 · T.B. Webb🇺🇸 · J.M. Elson🇺🇸 · D.E.M. Hoff🇺🇸 · C.D. Pruitt🇺🇸 · L.G. Sobotka🇺🇸 · P. Navratil🇨🇦 · G. Hupin🇫🇷 · K. Kravvaris🇺🇸 · S. Quaglioni🇺🇸 · K.W. Brown🇺🇸 · G. Cerizza🇺🇸 and 14 other authors
Excited states in 13O were investigated using inelastic scattering of an E/A=69.5-MeV 13O beam off of a 9Be target. The excited states were identified in the invariant-mass spectra of the decay products. Both single proton and sequential two-proton decays of the excited states were examined. For a number of the excited states, the protons were emitted with strong anisotropy where emissions transverse to the beam axis are favored. The measured proton-decay angular distributions were compared to predictions from distorted-wave born-approximation (DWBA) calculations of the spin alignment which was shown to be largely independent of the excitation mechanism. The deduced $^{13}$ O level scheme is compared to ab initio no-core shell model with continuum (NCSMC) predictions. The lowest-energy excited states decay isotropically consistent with predictions of strong proton 1s1/2 structure. Above these states in the level scheme, we observed a number of higher-spin states not predicted within the model. Possibly these are associated with rotational bands built on deformed cluster configurations predicted by antisymmetrized molecular dynamics (AMD) calculations. The spin alignment mechanism is shown to be useful for making spin assignments and may have widespread use.
↳ nucl-exnucl-thPRC(2021)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE

Thermal monopole condensation in QCD with physical quark masses

Interpretation of neutral charm mesons near threshold as unparticles

Spin contribution to the dissociation of bound states in rotating medium in magnetic field

Remarks on non-perturbative three--body dynamics and its application to the KKKˉ system

Using spin alignment of inelastically-excited fast beams to make spin assignments: the spectroscopy of 13O as a test case

Affiliations

Remarks on non-perturbative three--body dynamics and its application to the $K K K ˉ$ system