Nuclear Theory·nucl-th

Wednesday·June 10, 2015

7 papers—3 primary·4 cross-listed

01
[Submitted on 8 Jun 2015]
Estimate of the theoretical uncertainty of the cross sections for nucleon knockout in neutral-current neutrino-oxygen interactions
Artur M. Ankowski🇺🇸 · Maria B. Barbaro🇮🇹 · Omar Benhar🇺🇸 · Juan A. Caballero🇪🇸 · Carlotta Giusti🇮🇹 · Raúl González-Jiménez🇪🇸 · Guillermo D. Megias🇪🇸 · Andrea Meucci🇮🇹
Free nucleons propagating in water are known to produce gamma rays, which form a background to the searches for diffuse supernova neutrinos and sterile neutrinos carried out with Cherenkov detectors. As a consequence, the process of nucleon knockout induced by neutral-current quasielastic interactions of atmospheric (anti)neutrinos with oxygen needs to be under control at the quantitative level in the background simulations of the ongoing and future experiments. In this paper, we provide a quantitative assessment of the uncertainty associated with the theoretical description of the nuclear cross sections, estimating it from the discrepancies between the predictions of different models.
Comments:
7 pages, 2 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1506.02673 [pdf]
PRC(2015)·11 citations
02
[Submitted on 9 Jun 2015]
The torque effect and fluctuations of entropy deposition in rapidity in ultra-relativistic nuclear collisions
Piotr Bozek🇵🇱 · Wojciech Broniowski🇵🇱
The decorrelation of the orientation of the event-plane angles in the initial state of relativistic Pb-Pb and p-Pb collisions, the "torque effect," is studied in a model of entropy deposition in the longitudinal direction involving fluctuations of the longitudinal source profile on large scales. The radiation from a single wounded nucleon is asymmetric in space-time rapidity. It is assumed that the extent in rapidity of the region of deposited entropy is random. Fluctuations in the deposition of entropy from each source increase the event-plane decorrelation: for Pb-Pb collisions they improve the description of the data, while for p-Pb collisions the mechanism is absolutely essential to generate any sizable decorrelation. We also show that the experimental data for rank-four flow may be explained via folding of the elliptic flow. The results suggest the existence of long range fluctuations in the space-time distribution of entropy in the initial stages of relativistic nuclear collisions.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1506.02817 [pdf]
PLB(2016)·75 citations
03
[Submitted on 9 Jun 2015]
Quantifying jet transport properties via large $p_{T}$ hadron production
Zhi-Quan Liu🇨🇳 · Hanzhong Zhang🇨🇳 · Ben-Wei Zhang🇨🇳 · Enke Wang🇨🇳
Nuclear modification factor $R_{AA}$ for large $p_{T}$ single hadron is studied in a next-to-leading order (NLO) perturbative QCD (pQCD) parton model with medium-modified fragmentation functions (mFFs) due to jet quenching in high-energy heavy-ion collisions. The energy loss of the hard partons in the QGP is incorporated in the mFFs which utilize two most important parameters to characterize the transport properties of the hard parton jets: the jet transport parameter $q^_{0}$ and the mean free path $λ_{0}$ , both at the initial time $τ_{0}$ . A phenomenological study of the experimental data for $R_{AA} (p_{T})$ is performed to constrain the two parameters with simultaneous $χ^{2} / d.o.f$ fits to RHIC as well as LHC data. We obtain for energetic quarks $q^_{0} \approx 1.1 \pm 0.2$ GeV $^{2}$ /fm and $λ_{0} \approx 0.4 \pm 0.03$ fm in central $A u + A u$ collisions at $s_{N N} = 200$ GeV, while $q^_{0} \approx 1.7 \pm 0.3$ GeV $^{2}$ /fm, and $λ_{0} \approx 0.5 \pm 0.05$ fm in central $P b + P b$ collisions at $s_{N N} = 2.76$ TeV. Numerical analysis shows that the best fit favors a multiple scattering picture for the energetic jets propagating through the bulk medium, with a moderate averaged number of gluon emissions. Based on the best constraints for $λ_{0}$ and $τ_{0}$ , the estimated value for the mean-squared transverse momentum broadening is moderate which implies that the hard jets go through the medium with small reflection.
Comments:
8 pages, 6 figures, revised version
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1506.02840 [pdf]
EPJC(2016)·41 citations

Affiliations

first authorsco-authorsvia INSPIRE

Estimate of the theoretical uncertainty of the cross sections for nucleon knockout in neutral-current neutrino-oxygen interactions

The torque effect and fluctuations of entropy deposition in rapidity in ultra-relativistic nuclear collisions

Quantifying jet transport properties via large pT​ hadron production

Affiliations

Quantifying jet transport properties via large $p_{T}$ hadron production