Nuclear Theory·nucl-th

Wednesday·December 8, 2021

11 papers—6 primary·5 cross-listed

07
Pole position of the $a_{1} (1260)$ resonance in a three-body unitary framework
Daniel Sadasivan🇺🇸 · Andrei Alexandru🇺🇸 · Hakan Akdag🇩🇪 · Felipe Amorim🇺🇸 · Ruairí Brett🇺🇸 · Chris Culver🇬🇧 · Michael Döring🇺🇸 · Frank X. Lee🇺🇸 · Maxim Mai🇺🇸
Masses, widths, and branching ratios of hadronic resonances are quantified by their pole positions and residues with respect to transition amplitudes on the Riemann sheets of the complex energy-plane. In this study we discuss the analytic structure in the physical energy region of three-body scattering amplitudes on such manifolds. As an application, we determine the pole position of the $a_{1} (1260)$ meson from the ALEPH experiment by allowing for $π ρ$ coupled channels in S- and D-wave. We find it to be $s_{0} = (123 2_{- 0 - 11}^{+ 15 + 9} - i 26 6_{- 22 - 27}^{+ 0 + 15}) MeV$ .
↳ hep-phnucl-exnucl-thPRD(2022)·50 citations
08
Nuclear Charge Radii of the Nickel Isotopes $^{58 - 68, 70}$ Ni
S. Malbrunot-Ettenauer🇨🇭 · S. Kaufmann🇩🇪 · S. Bacca🇩🇪 · C. Barbieri🇬🇧 · J. Billowes🇬🇧 · M. L. Bissell🇬🇧 · K. Blaum🇩🇪 · B. Cheal🇬🇧 · T. Duguet🇫🇷 · R. F. Garcia Ruiz🇨🇭 · W. Gins🇧🇪 · C. Gorges🇩🇪 and 29 other authors
Collinear laser spectroscopy is performed on the nickel isotopes $^{58 - 68, 70}$ Ni, using a time-resolved photon counting system. From the measured isotope shifts, nuclear charge radii $R_{c}$ are extracted and compared to theoretical results. Three ab initio approaches all employ, among others, the chiral interaction NNLO $_{sat}$ , which allows an assessment of their accuracy. We find agreement with experiment in differential radii $δ ⟨ r_{c}^{2} ⟩$ for all employed ab initio methods and interactions, while the absolute radii are consistent with data only for NNLO $_{sat}$ . Within nuclear density functional theory, the Skyrme functional SV-min matches experiment more closely than the Fayans functional Fy( $Δ r$ ,HFB).
↳ nucl-exnucl-thPRL(2022)·78 citations
09
Sum rule for the partial decay rates of bottom hadrons based on the dynamical supersymmetry of the $s ˉ$ quark and the $u d$ diquark
Taiju Amano🇯🇵 · Daisuke Jido🇯🇵 · Stefan Leupold🇸🇪
We investigate the weak decays of $B ˉ_{s}^{0}$ and $Λ_{b}$ to charm hadrons based on the dynamical supersymmetry between the $s ˉ$ quark and the $u d$ diquark. We derive a new sum rule relating the decay rates of the processes $B ˉ_{s}^{0} \to D_{s}^{+} P^{-}$ , $B ˉ_{s}^{0} \to D_{s}^{*+} P^{-}$ and $Λ_{b} \to Λ_{c} P^{-}$ , where $P^{-}$ is a negatively charged meson, such as $π^{-}$ and $K^{-}$ . It is found that the observed decay rates satisfy the sum rule very well. This implies that the supersymmetry between the $s ˉ$ quark and the $u d$ diquark is also seen in the wavefunctions of the heavy hadrons and suggests that the $u d$ diquark can be regarded as a valid effective constituent for heavy hadrons.
↳ hep-phnucl-thPRD(2022)·6 citations
10
On transverse momentum broadening in real-time lattice simulations of the glasma and in the weak-field limit
Andreas Ipp🇦🇹 · David I. Müller🇦🇹 · Daniel Schuh🇦🇹
In these proceedings, we report on our numerical lattice simulations of partons traversing the boost-invariant, non-perturbative glasma as created at the early stages of collisions at RHIC and LHC. Since these highly energetic partons are produced from hard scatterings during heavy-ion collisions, they are already affected by the first stage of the medium's time evolution, the glasma, which is the pre-equilibrium precursor state of the quark-gluon plasma. We find that partons quickly accumulate transverse momentum up to the saturation momentum during the glasma stage. Moreover, we observe an interesting anisotropy in transverse momentum broadening of partons with larger broadening in the rapidity than in the azimuthal direction. Its origin can be related to correlations among the longitudinal color-electric and color-magnetic flux tubes in the initial state of the glasma. We compare these observations to the semi-analytic results obtained by a weak-field approximation, where we also find such an anisotropy in a parton's transverse momentum broadening.
↳ hep-phhep-latnucl-thEPJ Web Conf.(2022)·1 citation
11
Event topology and global observables in heavy-ion collisions at the Large Hadron Collider
Suraj Prasad🇮🇳 · Neelkamal Mallick🇮🇳 · Debadatta Behera🇮🇳 · Raghunath Sahoo🇮🇳 · Sushanta Tripathy🇮🇹
Particle production and event topology are very strongly correlated in high-energy hadronic and nuclear collisions. Event topology is decided by the underlying particle production dynamics and medium effects. Transverse spherocity is an event shape observable, which has been used in pp and heavy-ion collisions to separate the events based on their geometrical shapes. It has the unique capability to distinguish between jetty and isotropic events. In this work, we have implemented transverse spherocity in Pb-Pb collisions at $s_{NN}$ = 5.02 TeV using A Multi-Phase Transport Model (AMPT). While awaiting for experimental explorations, we perform a feasibility study of dependence of transverse spherocity on some of the global observables in heavy-ion collisions at the Large Hadron Collider energies. These global observables include the Bjorken energy density ( $ϵ_{B_{j}}$ ), speed of sound ( $c_{s}^{2}$ ) in the medium and the kinetic freeze-out properties for different collision centralities. The present study reveals about the usefulness of event topology dependent measurements in heavy-ion collisions in contrast to proton-proton collisions.
↳ hep-phhep-exnucl-exnucl-thSci.Rep.(2022)·34 citations

Affiliations

first authorsco-authorsvia INSPIRE

Pole position of the a1​(1260) resonance in a three-body unitary framework

Nuclear Charge Radii of the Nickel Isotopes 58−68,70Ni

Sum rule for the partial decay rates of bottom hadrons based on the dynamical supersymmetry of the sˉ quark and the ud diquark

On transverse momentum broadening in real-time lattice simulations of the glasma and in the weak-field limit

Event topology and global observables in heavy-ion collisions at the Large Hadron Collider

Affiliations

Pole position of the $a_{1} (1260)$ resonance in a three-body unitary framework

Nuclear Charge Radii of the Nickel Isotopes $^{58 - 68, 70}$ Ni

Sum rule for the partial decay rates of bottom hadrons based on the dynamical supersymmetry of the $s ˉ$ quark and the $u d$ diquark