Nuclear Theory·nucl-th

Thursday·September 14, 2017

10 papers—5 primary·5 cross-listed

06
[Submitted on 13 Sept 2017] (cross-list from hep-ph)
Prompt photon production and photon-jet correlations at the LHC
M. Klasen🇩🇪 · C. Klein-Bösing🇩🇪 · H. Poppenborg🇩🇪
Next-to-leading order predictions matched to parton showers are compared with recent ATLAS data on inclusive photon production and CMS data on associated photon and jet production in pp and pPb collisions at different centre-of-mass energies of the LHC. We find good agreement and, as expected, considerably reduced scale uncertainties compared to previous theoretical calculations. Predictions are made for the ratio of inclusive photons over decay photons $R_{γ}$ , an important quantity to evaluate the significance of additional photon sources, e.g. thermal radiation from a Quark-Gluon-Plasma, and for distributions in the parton momentum fraction in lead ions $x_{Pb}^{obs}$ , that could be determined by ALICE, ATLAS, CMS and LHCb in ongoing analyses of photon+jet production in pPb collisions at $s_{N N} = 5.02$ TeV. These data should have an important impact on the determination of nuclear effects such as shadowing at low $x$ .
Comments:
20 pages, 13 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1709.04154 [pdf]
JHEP(2018)·33 citations
07
[Submitted on 13 Sept 2017] (cross-list from astro-ph.SR)
Thermonuclear $^{19}$ F( $p$ , $α_{0}$ ) $^{16}$ O reaction rate
J.J. He · I. Lombardo · D. Dell'Aquila · Y. Xu · L.Y. Zhang · W.P. Liu
The thermonuclear $^{19}$ F( $p$ , $α_{0}$ ) $^{16}$ O reaction rate in a temperature region of 0.007--10 GK has been derived by re-evaluating the available experimental data, together with the low-energy theoretical $R$ -matrix extrapolations. Our new rate deviates up to about 30\% compared to the previous ones, although all rates are consistent within the uncertainties. At very low temperature (e.g. 0.01 GK) our reaction rate is about 20\% smaller than the most recently published rate, because of a difference in the low energy extrapolated $S$ -factor and a more accurate estimate of the reduced mass entering in the calculation of the reaction rate. At temperatures above $\sim$ 1 GK, our rate is smaller, for instance, by about 20\% around 1.75 GK, because we have re-evaluated in a meticulous way the previous data (Isoya et al., Nucl. Phys. 7, 116 (1958)). The present interpretation is supported by the direct experimental data. The uncertainties of the present evaluated rate are estimated to be about 20\% in the temperature region below 0.2 GK, which are mainly caused by the lack of low-energy experimental data and the large uncertainties of the existing data. The asymptotic giant branch (AGB) star evolves at temperatures below 0.2 GK, where the $^{19}$ F( $p$ , $α$ ) $^{16}$ O reaction may play a very important role. However, the current accuracy of the reaction rate is insufficient to help to describe, in a careful way, for the fluorine overabundances phenomenon observed in AGB stars. Precise cross section (or $S$ factor) data in the low energy region are therefore mandatory for astrophysical nucleosynthesis studies.
Comments:
11 pages, 13 figures
Subjects:
Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1709.04170 [pdf]
CPC(2018)·27 citations
08
[Submitted on 13 Sept 2017] (cross-list from hep-ph)
Strong and radiative decays of the low-lying $S$ - and $P$ -wave singly heavy baryons
Kai-Lei Wang🇨🇳 · Ya-Xiong Yao🇨🇳 · Xian-Hui Zhong🇨🇳 · Qiang Zhao🇨🇳
The strong and radiative decays of the low-lying $S$ - and $P$ -wave $Λ_{c (b)}$ , $Σ_{c (b)}$ , $Ξ_{c (b)}$ , $Ξ_{c (b)}^{'}$ and $Ω_{c (b)}$ baryons are systematically studied in a constituent quark model. We find that the radiative decay mode $Λ_{b}^{0} γ$ could be very useful for us to establish the missing neutral states $Σ_{b}^{0}$ and $Σ_{b}^{* 0}$ . Our calculation shows that most of those missing $λ$ -mode $P$ -wave singly heavy baryons have relatively narrow decay width of less than 30 MeV. Their dominant strong and radiative decay channels can be ideal for searching for their signals in future experiment. Configuration mixings between the $J^{P} = 1/ 2^{-}$ states $∣^{2} P_{λ} \frac{1}{2}^{-} ⟩$ and $∣^{4} P_{λ} \frac{1}{2}^{-} ⟩$ of the $6_{F}$ multiplet are discussed. The $Ξ_{c} (2930)^{0}$ state seems to favor the mixed state $∣ Ξ_{c}^{'} P_{λ} \frac{1}{2}^{-} ⟩_{2}$ with $J^{P} = 1/ 2^{-}$ . The $Σ_{c} (2800)$ resonance may be assigned to $∣ Σ_{c}^{2} P_{λ} \frac{3}{2}^{-} ⟩$ with $J^{P} = 3/ 2^{-}$ or $∣ Σ_{c}^{4} P_{λ} \frac{5}{2}^{-} ⟩$ with $J^{P} = 5/ 2^{-}$ . In general, the excitations of $∣^{2} P_{λ} \frac{3}{2}^{-} ⟩$ and $∣^{4} P_{λ} \frac{5}{2}^{-} ⟩$ of the $6_{F}$ multiplet have similar strong decay properties. In order to to identify them, angular distributions of their decays in either strong decay modes or radiative transitions should be needed.
Comments:
19 pages, 8 figures, 10 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1709.04268 [pdf]
PRD(2017)·146 citations
09
[Submitted on 13 Sept 2017] (cross-list from physics.atom-ph)
Laser-induced electronic bridge for characterization of the $^{229 m} Th \to^{229 g} Th$ nuclear transition with a tunable optical laser
Pavlo V. Bilous · Ekkehard Peik · Adriana Pálffy
An alternative method to determine the excitation energy of the $^{229 m} Th$ isomer via the laser-induced electronic bridge is investigated theoretically. In the presence of an optical or ultra-violet laser at energies that fulfill a two-photon resonance condition, the excited nuclear state can decay by transfering its energy to the electronic shell. A bound electron is then promoted to an excited state by absorption of a laser photon and simultaneous de-excitation of the nucleus. We present calculated rates for the laser-induced electronic bridge process and discuss the experimental requirements for the corresponding setup. Our results show that depending on the actual value of the nuclear transition energy, the rate can be very high, with an enhancement factor compared to the radiative nuclear decay of up to $1 0^{8}$ .
Comments:
11 pages, 3 figures, 4 tables
Subjects:
Atomic Physics (physics.atom-ph); Nuclear Theory (nucl-th)
arXiv:
1709.04364 [pdf]
New J.Phys.(2018)·19 citations
10
[Submitted on 13 Sept 2017] (cross-list from hep-ph)
Criticality in a Hadron Resonance Gas model with the van der Waals interaction
Subhasis Samanta🇮🇳 · Bedangadas Mohanty🇮🇳
The van der Waals interaction is implemented in a Hadron Resonance Gas model. It is shown that this model can describe Lattice QCD data of different thermodynamical quantities satisfactorily with the van der Waals parameters $a = 1250 \pm 150$ MeV fm $^{3}$ and $r = 0.7 \pm 0.05$ fm. Further, a phase transition is observed in this model with the critical point at temperature, $T = 62.1$ MeV and baryon chemical potential, $μ_{B} = 708$ MeV.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1709.04446 [pdf]
PRC(2018)·52 citations

Affiliations

first authorsco-authorsvia INSPIRE

Prompt photon production and photon-jet correlations at the LHC

Thermonuclear 19F(p,α0​)16O reaction rate

Strong and radiative decays of the low-lying S- and P-wave singly heavy baryons

Laser-induced electronic bridge for characterization of the 229mTh→ 229gTh nuclear transition with a tunable optical laser

Criticality in a Hadron Resonance Gas model with the van der Waals interaction

Affiliations

Thermonuclear $^{19}$ F( $p$ , $α_{0}$ ) $^{16}$ O reaction rate

Strong and radiative decays of the low-lying $S$ - and $P$ -wave singly heavy baryons

Laser-induced electronic bridge for characterization of the $^{229 m} Th \to^{229 g} Th$ nuclear transition with a tunable optical laser