Nuclear Theory·nucl-th

Monday·April 17, 2023

5 papers—1 primary·4 cross-listed

02
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 $^{2}$ .
↳ hep-phnucl-thquant-phEPL(2023)·0 citations
03
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.
↳ hep-phnucl-thEPJC(2024)·19 citations
04
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.
↳ hep-phhep-exnucl-th8 citations
05
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.
↳ hep-phnucl-exnucl-thSciPost Phys.(2024)·16 citations

Affiliations

first authorsco-authorsvia INSPIRE

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 $ψ (4230)$