Nuclear Theory·nucl-th

Friday·September 8, 2017

8 papers—4 primary·4 cross-listed

05
[Submitted on 7 Sept 2017] (cross-list from hep-ph)
Observation of the isospin breaking decay $Υ (10860) \to Υ (1 S) f_{0} (980) \to Υ (1 S) η π^{0}$ with the Belle II detector
N.N. Achasov🇷🇺 · G.N. Shestakov🇷🇺
Using the Belle data on the decay $Υ (10860) \to Υ (1 S) f_{0} (980) \to Υ (1 S) π^{+} π^{-}$ , we estimate the fraction of the process $Υ (10860) \to Υ (1 S) f_{0} (980) \to Υ (1 S) η π^{0}$ , caused by the mixing of $a_{0}^{0} (980)$ and $f_{0} (980)$ resonances that breaks the isotopic invariance due to the $K^{+}$ and $K^{0}$ meson mass difference. With an instantaneous luminosity of $8 \times 1 0^{35}$ cm $^{2} \cdot$ \,s $^{- 1}$ at the SuperKEKB collider, one can collect with the Belle II detector about a hundred $Υ (10860) \to Υ (1 S) η π^{0}$ events in the narrow region of the $η π^{0}$ invariant mass near the $K K ˉ$ thresholds in a time roughly spent on the present Belle experiment.
Comments:
5 pages, 2 figures; the comment is added, Ref. [6], that the using of the Flatte propagators for the $f_{0} (980)$ and $a_{0} (980)$ states with the masses under the $K K ˉ$ thresholds requires the renormalization of the masses!
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1709.02068 [pdf]
PRD(2017)·7 citations
06
[Submitted on 7 Sept 2017] (cross-list from hep-ph)
Light Pseudoscalar Mesons: an Inverse Instantaneous Bethe-Salpeter Glimpse
Wolfgang Lucha🇦🇹 · Franz F. Schoberl🇦🇹
Achieving self-consistent simultaneous interpretations of pions and kaons as bound states of quark and antiquark and as the (almost) massless boson states related, according to Goldstone's theorem, to the dynamical (and explicit) breakdown of the chiral symmetries of QCD still represents a major challenge. Applying inversion techniques to conveniently simplified versions of the homogeneous Bethe-Salpeter equation, governing bound states in quantum field theory, enables us to get along a straightforward route a qualitative idea of how the underlying effective interaction might look like.
Comments:
4 pages, 4 figures, contributed to "The European Physical Society Conference on High Energy Physics - EPS-HEP 2017" (5 - 12 July 2017, Venice, Italy)
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1709.02130 [pdf]
PoS(2017)·1 citation
07
[Submitted on 7 Sept 2017] (cross-list from hep-ph)
Decay Constants of the Heavy-Light Mesons $D^{(*)}$ and $B^{(*)}$ : Isospin Breaking
Wolfgang Lucha🇦🇹 · Dmitri Melikhov🇦🇹 · Silvano Simula🇮🇹
QCD sum rules are analytic predictions of hadron observables from quantum chromodynamics. In the so-called local-duality limit of their Borel-transformed form, all nonperturbative contributions are encompassed by just a single quantity, an effective threshold beyond which, by assumption, all hadronic contributions are reliably described by perturbative QCD. Reconstructing its quark-mass dependence enables us to investigate the differences of the leptonic decay constants of heavy-light mesons effectuated by the tiny isospin-violating discrepancy of the masses of up and down quarks. By and large, our findings enjoy excellent agreement with the outcomes of earlier studies, the only exception being a lattice-QCD prediction for the $B$ mesons, where we find dramatic disagreement.
Comments:
4 pages, 1 figure, contributed to "The European Physical Society Conference on High Energy Physics - EPS-HEP 2017" (5 - 12 July 2017, Venice, Italy)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
1709.02131 [pdf]
PoS(2017)·4 citations
08
[Submitted on 7 Sept 2017] (cross-list from hep-ph)
Collisional and thermal dissociation of $J / ψ$ and $Υ$ states at the LHC
Samuel Aronson🇺🇸 · Evan Borras🇺🇸 · Brunel Odegard🇺🇸 · Rishi Sharma🇮🇳 · Ivan Vitev🇺🇸
We present new results for the suppression of high transverse momentum charmonium [ $J / ψ, ψ (2 S)$ ] and bottomonium [ $Υ (1 S), Υ (2 S), Υ (3 S)$ ] states in Pb+Pb collisions at the Large Hadron Collider. Our theoretical formalism combines the collisional dissociation of quarkonia, as they propagate in the quark-gluon plasma, with the thermal wavefunction effects due to the screening of the $Q Q ˉ$ attractive potential in the medium. We find that a good description of the relative suppression of the ground and higher excited quarkonium states, transverse momentum and centrality distributions is achieved, when comparison to measurements at a center-of-mass energy of 2.76 TeV is performed. Theoretical predictions for the highest Pb+Pb center-of-mass energy of 5.02 TeV at the LHC, where new experimental results are being finalized, are also presented.
Comments:
8 pages, 8 eps figures; 2 figures and references added, introduction restructured; version to appear in PLB
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1709.02372 [pdf]
PLB(2018)·63 citations

Affiliations

first authorsco-authorsvia INSPIRE

Observation of the isospin breaking decay Υ(10860)→Υ(1S)f0​(980)→Υ(1S)ηπ0 with the Belle II detector

Light Pseudoscalar Mesons: an Inverse Instantaneous Bethe-Salpeter Glimpse

Decay Constants of the Heavy-Light Mesons D(∗) and B(∗): Isospin Breaking

Collisional and thermal dissociation of J/ψ and Υ states at the LHC

Affiliations

Observation of the isospin breaking decay $Υ (10860) \to Υ (1 S) f_{0} (980) \to Υ (1 S) η π^{0}$ with the Belle II detector

Decay Constants of the Heavy-Light Mesons $D^{()}$ and $B^{()}$ : Isospin Breaking

Collisional and thermal dissociation of $J / ψ$ and $Υ$ states at the LHC