Nuclear Theory·nucl-th

Wednesday·August 2, 2023

14 papers—8 primary·6 cross-listed

09
[Submitted on 31 Jul 2023] (cross-list from hep-ph)
Back-to-back inclusive dijets in DIS at small $x$ : Complete NLO results and predictions
Paul Caucal🇫🇷 · Farid Salazar🇺🇸 · Björn Schenke🇺🇸 · Tomasz Stebel🇵🇱 · Raju Venugopalan🇺🇸
We compute the back-to-back dijet cross-section in deep inelastic scattering (DIS) at small $x$ to next-to-leading order (NLO) in the Color Glass Condensate effective field theory. Our result can be factorized into a convolution of the Weizsäcker-Williams gluon transverse momentum dependent distribution function (WW gluon TMD) with a universal soft factor and an NLO coefficient function. The soft factor includes both double and single logarithms in the ratio of the relative transverse momentum $P_{⊥}$ of the dijet pair to the dijet momentum imbalance $q_{⊥}$ ; its renormalization group (RG) evolution is resummed into the Sudakov factor. Likewise, the WW TMD obeys a nonlinear RG equation in $x$ that is kinematically constrained to satisfy both lifetime and rapidity ordering of the projectile. Exact analytical expressions are obtained for the NLO coefficient function of transversely and longitudinally polarized photons. Our results allow for the first quantitative separation of the dynamics of Sudakov suppression from that of gluon saturation. They can be extended to other final states and provide a framework for precision tests of novel QCD many-body dynamics at the Electron-Ion Collider.
Comments:
41 pages, 9 figures, 5 supplemental materials, to be published in Physical Review Letters
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2308.00022 [pdf]
PRL(2024)·83 citations
10
[Submitted on 31 Jul 2023] (cross-list from hep-ph)
A Formalism for Extracting Track Functions from Jet Measurements
Kyle Lee🇺🇸 · Ian Moult🇺🇸 · Felix Ringer🇺🇸 · Wouter J. Waalewijn🇳🇱
The continued success of the jet substructure program will require widespread use of tracking information to enable increasingly precise measurements of a broader class of observables. The recent reformulation of jet substructure in terms of energy correlators has simplified the incorporation of universal non-perturbative matrix elements, so called "track functions", in jet substructure calculations. These advances make it timely to understand how these universal non-perturbative functions can be extracted from hadron collider data, which is complicated by the use jet algorithms. In this paper we introduce a new class of jet functions, which we call (semi-inclusive) track jet functions, which describe measurements of the track energy fraction in identified jets. These track jet functions can be matched onto the universal track functions, with perturbatively calculable matching coefficients that incorporate the jet algorithm dependence. We perform this matching, and present phenomenological results for the charged energy fraction in jets at the LHC and EIC/HERA at collinear next-to-leading logarithmic accuracy. We show that higher moments of the charged energy fraction directly exhibit non-linear Lorentzian renormalization group flows, allowing the study of these flows with collider data. Our factorization theorem enables the extraction of universal track functions from jet measurements, opening the door to their use for a precision jet substructure program.
Comments:
22 pages, 8 beautiful figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2308.00028 [pdf]
JHEP(2024)·26 citations
11
[Submitted on 31 Jul 2023] (cross-list from hep-ph)
Study of the azimuthal asymmetry in heavy ion collisions combining initial state momentum orientation and final state collective effects
Lucas Soster Moriggi🇧🇷 · Érison dos Santos Rocha🇧🇷 · Magno Valério Trindade Machado🇧🇷
In the present work we investigate the source of azimuthal asymmetry for nuclear collision using a model that contemplates particles produced in the initial hard collisions and the collective effects described by a Blast-Wave like expansion. The latter is described by the relaxation time approximation of the Boltzmann transport equation. The parameters regarding collective flow and asymmetry are fitted by the experimental data from $p_{T}$ spectrum and $v_{2}$ for PbPb and XeXe collisions at different centrality classes. As a by-product the ratio of final elliptic flow with the initial anisotropy, $v_{2} / ϵ_{2}$ , and the average transverse momentum are predicted.
Comments:
Version to be published in Physical Review D
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2308.00181 [pdf]
PRD(2023)·4 citations
12
[Submitted on 1 Aug 2023] (cross-list from hep-ph)
Inclusive, prompt and non-prompt $J / ψ$ identification in proton-proton collisions at the Large Hadron Collider using machine learning
Suraj Prasad🇮🇳 · Neelkamal Mallick🇮🇳 · Raghunath Sahoo🇮🇳
Studies related to $J / ψ$ meson, a bound state of charm and anti-charm quarks ( $c c ˉ$ ), in heavy-ion collisions, provide genuine testing grounds for the theory of strong interaction, quantum chromodynamics (QCD). To better understand the underlying production mechanism, cold nuclear matter effects, and influence from the quark-gluon plasma, baseline measurements are also performed in proton-proton ( $pp$ ) and proton-nucleus ( $p$ --A) collisions. The inclusive $J / ψ$ measurement has contributions from both prompt and non-prompt productions. The prompt $J / ψ$ is produced directly from the hadronic interactions or via feed-down from directly produced higher charmonium states, whereas non-prompt $J / ψ$ comes from the decay of beauty hadrons. In experiments, $J / ψ$ is reconstructed through its electromagnetic decays to lepton pairs, in either $e^{+} + e^{-}$ or $μ^{+} + μ^{-}$ decay channels. In this work, for the first time, machine learning techniques are implemented to separate the prompt and non-prompt dimuon pairs from the background to obtain a better identification of the $J / ψ$ signal for different production modes. The study has been performed in $pp$ collisions at $s = 7$ and 13 TeV simulated using PYTHIA8. Machine learning models such as XGBoost and LightGBM are explored. The models could achieve up to 99\% prediction accuracy. The transverse momentum ( $p_{T}$ ) and rapidity ( $y$ ) differential measurements of inclusive, prompt, and non-prompt $J / ψ$ , its multiplicity dependence, and the $p_{T}$ dependence of fraction of non-prompt $J / ψ$ ( $f_{B}$ ) are shown. These results are compared to experimental findings wherever possible.
Comments:
Same as the published version in Phys. Rev. D
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2308.00329 [pdf]
PRD(2024)·17 citations
13
[Submitted on 1 Aug 2023] (cross-list from hep-th)
Stark effect and dissociation of mesons in holographic conductor
Shuta Ishigaki🇨🇳 · Shunichiro Kinoshita🇯🇵 · Masataka Matsumoto🇨🇳
We study the meson spectrum of the $N = 4$ supersymmetric Yang-Mills theory with $N = 2$ fundamental hypermultiplets for a finite electric field by using the D3/D7 model. The spectrum for scalar and vector mesons is computed by analyzing the (quasi-)normal modes for the fluctuations of the D7-brane embedding and gauge fields. In the presence of an electric field, two different phases in the background are realized: the meson and dissociation phases. In this paper, we analyze the meson spectrum of scalar and vector mesons for all ranges of the electric field and explore the effect of the electric field on the meson spectrum, that is, the Stark effect. In the meson spectrum, we observe the avoided crossing between different levels due to the coupling of fluctuations via the electric field.
Comments:
31 pages, 12 figures. v2: match published version
Subjects:
High Energy Physics — Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); Nuclear Theory (nucl-th)
arXiv:
2308.00361 [pdf]
JHEP(2023)·3 citations
14
[Submitted on 1 Aug 2023] (cross-list from hep-ph)
Exploring robust correlations between fermionic dark matter model parameters and neutron star properties: A two-fluid perspective
Prashant Thakur🇮🇳 · Tuhin Malik🇵🇹 · Arpan Das🇵🇱 · T. K. Jha🇮🇳 · Constança Providência🇵🇹
The current observational properties of neutron stars have not definitively ruled out the possibility of dark matter. In this study, we primarily focus on exploring correlations between the dark matter model parameters and different neutron star properties using a rich set of EOSs. We adopt a two-fluid approach to calculate the properties of neutron stars. For the nuclear matter EOS, we employ several realistic EOS derived from the relativistic mean field model (RMF), each exhibiting varying stiffness and composition. In parallel, we look into the dark matter EOS, considering fermionic matter with repulsive interaction described by a relativistic mean field Lagrangian. A reasonable range of parameters is sampled meticulously. Interestingly, our results reveal a promising correlation between the dark matter model parameters and stellar properties, particularly when we ignore the uncertainties in the nuclear matter EOS. However, when introducing uncertainties in the nuclear sector, the correlation weakens, suggesting that the task of conclusively constraining any particular dark matter model might be challenging using global properties alone, such as mass, radius, and tidal deformability. Notably, we find that dark-matter admixed stars tend to have higher central baryonic density, potentially allowing for non-nucleonic degrees of freedom or direct Urca processes in stars with lower masses. There is also a tantalizing hint regarding the detection of stars with the same mass but different surface temperatures, which may indicate the presence of dark matter. With our robust and extensive dataset, we delve deeper and demonstrate that even in the presence of dark matter, the semi-universal C-Love relation remains intact.
Comments:
15 Pages, 12 figures, 4 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2308.00650 [pdf]
PRD(2024)·54 citations

Affiliations

first authorsco-authorsvia INSPIRE

Back-to-back inclusive dijets in DIS at small x: Complete NLO results and predictions

A Formalism for Extracting Track Functions from Jet Measurements

Study of the azimuthal asymmetry in heavy ion collisions combining initial state momentum orientation and final state collective effects

Inclusive, prompt and non-prompt J/ψ identification in proton-proton collisions at the Large Hadron Collider using machine learning

Stark effect and dissociation of mesons in holographic conductor

Exploring robust correlations between fermionic dark matter model parameters and neutron star properties: A two-fluid perspective

Affiliations

Back-to-back inclusive dijets in DIS at small $x$ : Complete NLO results and predictions

Inclusive, prompt and non-prompt $J / ψ$ identification in proton-proton collisions at the Large Hadron Collider using machine learning