Nuclear Theory·nucl-th

Monday·April 17, 2023

5 papers—1 primary·4 cross-listed

01
[Submitted on 14 Apr 2023]
Dynamic scaling of order parameter fluctuations in model B
Chandrodoy Chattopadhyay🇺🇸 · Josh Ott🇺🇸 · Thomas Schaefer🇺🇸 · Vladimir Skokov🇺🇸
We describe numerical simulations of the stochastic diffusion equation with a conserved charge. We focus on the dynamics in the vicinity of a critical point in the Ising universality class. The model we consider is expected to describe the critical dynamics near a possible QCD critical point if the coupling of the order parameter to the momentum density of the fluid can be neglected. The simulations are performed on a spatial lattice, and the time evolution is performed using a Metropolis algorithm. We determine the dynamical critical exponent $z ≃ 3.972 (2)$ , which agrees with predictions of the epsilon expansion. We also study non-equilibrium sweeps of the reduced temperature and observe approximate Kibble-Zurek scaling.
Comments:
19 pages, 9 figures. Version published in PRD
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2304.07279 [pdf]
PRD(2023)·23 citations
02
[Submitted on 13 Apr 2023] (cross-list from hep-ph)
Significance of classically forbidden regions for short baseline neutrino experiments
Dharam Vir Ahluwalia🇮🇳
Classically forbidden regions ( $CFRs$ ) are common to both non-relativistic quantum mechanics, and to relativistic quantum field theory. It is known since 2001 that $CFR$ contributes roughly sixteen percent of energy to the ground state of a simple harmonic oscillator (Adunas G. Z. et al., Gen. Relativ. Gravit., 33 (2001) 183). Similarly, quantum field theoretic arguments yield a non-zero amplitude for a massive particle to cross the light cone (that is, into the $CFR$ ). The signs of these amplitudes are opposite for fermions and antifermions. This has given rise to an erroneous conclusion that amplitude to cross the lightcone is identically zero. This is true as long as a measurement does not reveal the considered object to be a particle or antiparticle. However, neutrino oscillation experiments do measure a neutrino $ν$ , or an antineutrino $ν ˉ$ . Here we show that in the context of neutrino oscillations these observations have the potential to resolve various short baseline anomalies for a sufficiently light lowest mass eigenstate. In addition, we make a concrete prediction for the upcoming results to be announced later this year by JSNS $^{2}$ .
Comments:
10 pages, 3 Figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2304.06736 [pdf]
EPL(2023)·0 citations
03
[Submitted on 14 Apr 2023] (cross-list from hep-ph)
Evolution of structure functions in momentum space
Tuomas Lappi🇫🇮 · Heikki Mäntysaari🇫🇮 · Hannu Paukkunen🇫🇮 · Mirja Tevio🇫🇮
We formulate the momentum-space Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for structure functions measurable in deeply inelastic scattering. We construct a six-dimensional basis of structure functions that allows for a full three flavor structure and thereby provides a way to calculate perturbative predictions for physical cross sections directly without unobservable parton distribution functions (PDFs) and without the associated scheme dependence. We derive the DGLAP equations to first non-zero order in strong coupling $α_{s}$ , but the approach can be pursued to arbitrary order in perturbation theory. We also numerically check our equations against the conventional PDF formulation.
Comments:
14 pages, 2 figures, v3: Typos in Eqs. (40,41,64,68) corrected
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2304.06998 [pdf]
EPJC(2024)·19 citations
04
[Submitted on 14 Apr 2023] (cross-list from hep-ph)
A new look at $ψ (4160)$ and $ψ (4230)$
Zhi-Yong Zhou🇨🇳 · Chun-Yong Li🇨🇳 · Zhiguang Xiao🇨🇳
By simultaneously analyzing the cross section data of $e^{+} e^{-} \to D D ˉ, D D ˉ^{*}, D^{*} D ˉ^{*}, D D ˉ π$ in a coupled-channel scheme with unitarity, we found that, in contrast to the conventional wisdom, the pole of $ψ (2^{3} D_{1})$ might be located at about $s = 4222 - 32 i MeV$ . This observation implies a possibility that the two resonances, dubbed the $ψ (4160)$ and $ψ (4230)$ in the PDG table now, might be the same $ψ (2^{3} D_{1})$ state. Such a suggestion could provide more insight to our understanding the enigmatic decay properties of $ψ (4160)$ and $ψ (4230)$ . Furthermore, this coupled-channel scheme could be applied to study other phenomena with several interfering resonances.
Comments:
6 pages, 4 figures, 1 table
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2304.07052 [pdf]
8 citations
05
[Submitted on 14 Apr 2023] (cross-list from hep-ph)
Jet substructure observables for jet quenching in Quark Gluon Plasma: a Machine Learning driven analysis
Miguel Crispim Romão🇵🇹 · José Guilherme Milhano🇵🇹 · Marco van Leeuwen🇳🇱
We present a survey of a comprehensive set of jet substructure observables commonly used to study the modifications of jets resulting from interactions with the Quark Gluon Plasma in Heavy Ion Collisions. The \jewel{} event generator is used to produce simulated samples of quenched and unquenched jets. Three distinct analyses using Machine Learning techniques on the jet substructure observables have been performed to identify both linear and non-linear relations between the observables, and to distinguish the Quenched and Unquenched jet samples. We find that most of the observables are highly correlated, and that their information content can be captured by a small set of observables. We also find that the correlations between observables are resilient to quenching effects and that specific pairs of observables exhaust the full sensitivity to quenching effects. The code, the datasets, and instructions on how to reproduce this work are also provided.
Comments:
37 pages, 21 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2304.07196 [pdf]
SciPost Phys.(2024)·16 citations

Affiliations

first authorsco-authorsvia INSPIRE

Dynamic scaling of order parameter fluctuations in model B

Significance of classically forbidden regions for short baseline neutrino experiments

Evolution of structure functions in momentum space

A new look at ψ(4160) and ψ(4230)

Jet substructure observables for jet quenching in Quark Gluon Plasma: a Machine Learning driven analysis

Affiliations

A new look at $ψ (4160)$ and $ψ (4230)$