Nuclear Theory·nucl-th

Monday·April 4, 2016

9 papers—6 primary·3 cross-listed

07
[Submitted on 1 Apr 2016] (cross-list from hep-ph)
Mechanisms of the isospin-breaking decay $f_{1} (1285) \to f_{0} (980) π^{0} \to π^{+} π^{-} π^{0}$
N.N. Achasov🇷🇺 · A.A. Kozhevnikov🇷🇺 · G.N. Shestakov🇷🇺
Estimated are the contributions of the following mechanisms responsible for the decay $f_{1} (1285) \to f_{0} (980) π^{0} \to π^{+} π^{-} π^{0}$ : 1) the contribution of the $a_{0}^{0} (980) - f_{0} (980)$ mixing, $f_{1} (1285) \to a_{0} (980) π^{0} \to (K^{+} K^{-} + K^{0} K ˉ^{0}) π^{0} \to f_{0} (980) π^{0} \to π^{+} π^{-} π^{0}$ , 2) the contribution of the transition $f_{1} (1285) \to (K^{+} K^{-} + K^{0} K ˉ^{0}) π^{0} \to f_{0} (980) π^{0} \to π^{+} π^{-} π^{0}$ , arising due to the pointlike decay $f_{1} (1285) \to K K ˉ π^{0}$ , 3) the contribution of the transition $f_{1} (1285) \to (K^{*} K ˉ + K ˉ^{*} K) \to (K^{+} K^{-} + K^{0} K ˉ^{0}) π^{0} \to f_{0} (980) π^{0} \to π^{+} π^{-} π^{0}$ , where $K^{*} = K^{*} (892)$ , and 4) the contribution of the transition $f_{1} (1285) \to (K_{0}^{*} K ˉ + K ˉ_{0}^{*} K) \to (K^{+} K^{-} + K^{0} K ˉ^{0}) π^{0} \to f_{0} (980) \to π^{+} π^{-} π^{0}$ , where $K_{0}^{*} = K_{0}^{*} (800)$ (or $κ$ ) and $K_{0}^{*} (1430)$ . These mechanisms break the conservation of the isospin due to the nonzero mass difference of the $K^{+}$ and $K^{0}$ mesons. They result in the appearance of the narrow resonance structure in the $π^{+} π^{-}$ mass spectrum in the region of the $K K ˉ$ thresholds, with the width $\approx 2 m_{K^{0}} - 2 m_{K^{+}} \approx 8$ MeV. The observation of such a structure in experiment is the direct indication on the $K K ˉ$ loop mechanism of the breaking of the isotopic invariance. We point out that existing data should be more precise, and it is difficult to explain them using the single specific mechanism from those listed above. Taking the decay $f_{1} (1285) \to f_{0} (980) π^{0} \to π^{+} π^{-} π^{0}$ as the example, we discuss the general approach to the description of the $K K ˉ$ loop mechanism of the breaking of isotopic invariance.
Comments:
14 pages, 7 figures; v2: matches published version in PRD
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1604.00177 [pdf]
PRD(2016)·22 citations
08
[Submitted on 1 Apr 2016] (cross-list from hep-ph)
Single inclusive forward hadron production at next-to-leading order
B. Ducloué🇫🇮 · T. Lappi🇫🇮 · Y. Zhu🇫🇮
We discuss single inclusive hadron production from a high energy quark scattering off a strong target color field in the Color Glass Condensate formalism. Recent calculations of this process at the next-to-leading order accuracy have led to negative cross sections at large transverse momenta. We identify the origin of this problem as an oversubtraction of the rapidity divergence into the Balitsky-Kovchegov evolution equation for the target. We propose a new way to implement the kinematical restriction on the emitted gluons to overcome this difficulty.
Comments:
12 pages, 9 figures. v2: matches published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1604.00225 [pdf]
PRD(2016)·70 citations
09
[Submitted on 1 Apr 2016] (cross-list from hep-ph)
Initial State Quantum Fluctuations in the Little Bang
Francois Gelis🇫🇷 · Bjoern Schenke🇺🇸
We review recent developments in the ab-initio theoretical description of the initial state in heavy-ion collisions. We emphasize the importance of fluctuations, both for the phenomenological description of experimental data from the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), and the theoretical understanding of the non-equilibrium early time dynamics and thermalization of the medium.
Comments:
17 pages, 9 figures, Manuscript accepted by Annual Reviews of Nuclear and Particle Science
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1604.00335 [pdf]
Ann.Rev.Nucl.Part.Sci.(2016)·30 citations

Affiliations

first authorsco-authorsvia INSPIRE

Mechanisms of the isospin-breaking decay f1​(1285)→f0​(980)π0→π+π−π0

Single inclusive forward hadron production at next-to-leading order

Initial State Quantum Fluctuations in the Little Bang

Affiliations

Mechanisms of the isospin-breaking decay $f_{1} (1285) \to f_{0} (980) π^{0} \to π^{+} π^{-} π^{0}$