Mon·May 1, 2023Monday·May 1, 2023

1. 01*

   Quasi Transverse Momentum Dependent Distributions at Next-to-Next-to-Leading order

   Óscar del Río🇪🇸 · Alexey Vladimirov🇪🇸

   The partons' transverse momentum can be explored with QCD lattice simulations by studying the quasi-transverse-momentum-dependent parton distribution functions (qTMDPDFs), which are factorized in terms of physical TMDPDFs and soft factors in the limit of the large hadron's momentum. We present the next-to-next-to-leading order (NNLO) calculation of the coefficient function for this factorization. Together with already known expressions for anomalous dimensions, this result allows analysis of lattice data at NNLO perturbative accuracy.

   hep-phhep-latPRD(2023)·24 citations
2. 02*

   Naturally low scale type I seesaw mechanism and its viability in the 3-3-1 model with right-handed neutrinos

   E. Cabrera🇧🇷 · D. Cogollo🇧🇷 · C. A. de S. Pires

   Seesaw mechanisms are the simplest and the most elegant way of generating small masses for the active neutrinos $(m_{\nu })$. In these mechanisms $m_{\nu }$ is inversely proportional to the lepton number breaking scale $(M)$ that, in the particular case of the type I seesaw mechanism, is the Majorana mass of the right-handed neutrinos. In the canonical case right-handed neutrinos are supposed to be heavy belonging to the GUT scale. With the advent of the LHC people began to suppose these neutrinos having mass at TeV scale. In this case very tiny Yukawa couplings are required. As far as we know there are no constraints on the energy scales associated to the seesaw mechanisms. In what concern 3-3-1 models, when we trigger the type I seesaw mechanism the lepton number breaking scale that suppresses active neutrino masses contributes to the masses of the standard gauge bosons. Current data on $m_W$ demands the mechanism to be performed at GeV scale. As main implication we may have right handed neutrinos with mass varying from few keVs up to hundreds of GeVs. We also investigate the viability of the mechanism and found as interesting result that in the case in which the right-handed neutrino masses belong to the range keV-MeV scale, viability of the mechanism demands that the lightest of the right-handed neutrinos be stable, which makes of it a natural dark matter candidate, and that the lightest of the active neutrinos be much lighter than the other two active neutrinos.

   hep-phNPB(2023)·5 citations
3. 03*

   Superfast Quarks in Deuterium

   Dmitriy N. Kim🇺🇸 · Gerald A. Miller🇺🇸

   An extension to our previous study on Nuclear Parton Distribution Functions (nPDFs) using Light-Front Holographic Quantum Chromodynamics (LFHQCD) is presented. We focus on applying the effects of nucleon motion inside the nucleus (Fermi motion/smearing) to deuterium, extending our nPDFs (and hence the DIS $F_2$ structure function for deuterium, $F_2^D$) to the superfast, $x>1$, region. We utilize four different deuteron wavefunctions (AV18, NijmI, NijmII, Nijm93) in this study. We find that our model, with no additional new parameters, is in excellent agreement with deuterium EMC ratio data obtained from the BONuS experiment. Looking beyond conventional nuclear physics, and in anticipation of ongoing 12 GeV experiments at Jefferson Lab, we use a LFHQCD ansatz to predict the contributions of an exotic six-quark state to $F_2^D$ in the superfast region. Our results are that the effects of using other potentials are about the same magnitude as six-quark effects - both have small effects in $x<1$, but have significant contributions at $x>1$.

   hep-phnucl-exnucl-thPRC(2024)·0 citations
4. 04*

   Conserved number fluctuations under global rotation in a hadron resonance gas model

   Gaurav Mukherjee🇮🇳 · Dipanwita Dutta🇮🇳 · Dipak Kumar Mishra🇮🇳

   Net-baryon number, net-charge and net-strangeness fluctuations measured in ultra-relativistic heavy-ion collisions may reveal details and insights into the quark-hadron transition, hadrochemical freeze-out and possibly aid in the search of the QCD critical point. By scanning in collision energy, current and upcoming heavy-ion facilities aim to explore the finite density regime where the critical point may lie. Effects due to rotation are also expected in case of peripheral collisions and we report on conserved number susceptibilities as calculated in the hadron resonance gas model augmented by a global angular velocity. Since these quantities are directly related to the experimentally measurable moments of the corresponding distributions our results show the possible impact of vorticity on the theoretical baseline and should be useful for referencing with experimental data and QCD-based calculations.

   hep-phhep-exnucl-exnucl-thEPJC(2024)·13 citations
5. 05*

   Building models of quarks and gluons with an arbitrary number of colors using Cartan-Polyakov loops

   Renan Câmara Pereira🇵🇹 · Pedro Costa🇵🇹

   In this work we introduce the concept of Cartan-Polyakov loops, a special subset of Polyakov loops in the fundamental representation of the $\mathrm{SU}(N_c)$ group, with charges $k=1,\dots ,(N_c-1)/2$. It constitutes a sufficient set of independent degrees of freedom and it is used to parametrize the thermal Wilson line. Polyakov loops not contained in this set are classified as non-Cartan-Polyakov loops. Using properties of the characteristic polynomial of the thermal Wilson line, we write a non-Cartan-Polyakov loop charge decomposition formula. This formalism allows one to readily build effective models of quarks and gluons with an arbitrary number of colors. We apply it to the Polyakov$-$Nambu$-$Jona-Lasinio model and to an effective glue model, in the mean field approximation, showing how to directly extend these models to higher values of $N_c$.

   hep-phnucl-thNPB(2024)·2 citations
6. 06*

   Baryon-rich QCD matter

   Jochen Wambach🇩🇪

   Properties of high-density strong-interaction matter of relevance for astrophysical scenarios that involve neutron stars are discussed. It is argued that theoretical and experimental insights from the small baryo-chemical potential (${\mu }_B$) and high-temperature regions of the QCD phase diagram can guide realistic model building at high density, as this regime is currently not accessible to first-principles numerical calculations of the QCD partition function. Special attention is payed to the chiral properties of high-density matter and the nature of a possible first-order chiral phase transition. In this transition hadronic parity-partners, in particular baryons, become spectrally degenerate with finite (pole) masses, as expected from general insight into the mass generation in QCD. Possible signals in heavy-ion dielectron production at beam energies of a few GeV are discussed. Based on evidence for an emergent "chiral spin symmetry" above the pseudo-critical chiral transition temperature at small ${\mu }_B$, speculations on the physical state of dense hadronic matter beyond the chiral phase transition are presented.

   hep-phJ.Phys.Conf.Ser.(2023)·2 citations
7. 07*

   Molecular charmed baryons and pentaquarks from light-meson exchange saturation

   Mao-Jun Yan🇨🇳 · Fang-Zheng Peng🇨🇳 · Manuel Pavon Valderrama🇨🇳

   The spectrum of the $cqq$ baryons contains a few states whose nature is not clearly a three-quark composite and which might have a sizable baryon-meson component. Examples include the ${\Sigma }_c(2800)$ or the ${\Lambda }_c(2940)$. Here we explore the spectrum of two-body systems composed of a light, octet baryon and a charmed meson (or antimeson) within a simple contact-range theory in which the couplings are saturated by light-meson exchanges. This results in the prediction of a series of composite anticharmed pentaquarks ($\bar{c}qqqq$) and singly-charmed baryons ($c\bar{q}qqq$). Among the later we find $J=\frac{1}{2}$ $\Xi D$ and $J=\frac{3}{2}$ $\Xi D^{\ast }$ bound states with masses matching those of the recently observed ${\Omega }_c(3185)$ and ${\Omega }_c(3327)$ baryons.

   hep-phhep-exhep-latnucl-thPRD(2024)·29 citations
8. 08*

   Masses and magnetic moments of exotic fully heavy pentaquarks

   WenXuan Zhang🇨🇳 · HongTao An🇨🇳 · Duojie Jia🇨🇳

   Inspired by the observation of a resonant state $X(6600)$ of fully charm tetraquark by the CMS experiment of LHCb Collaboration in double $J/\psi$ decay channel, we perform a systematical study of all configurations of fully heavy pentaquarks $P_{Q_1{Q}_2{Q}_3{Q}_4\overline{Q_5}}$ ($Q_i=c,b$%, $i=1,2,3,4,5$) in their ground states in unified framework of MIT bag model. The color-spin wavefunctions of pentaquarks, classified via Young tableau and presented in terms of the Young-Yamanouchi bases, are used to compute masses and magnetic moments of fully heavy pentaquarks via numerical variational method, predicting a set of masses ranging from $8.229$ GeV for the $P_{cccc\bar{c}}$ to $24.770$ GeV for the $P_{bbbb\bar{b}}$. Combining with computed masses of fully heavy mesons and baryons, we find that masses of fully heavy hadrons(mesons, baryons, tetraquarks and pentaquarks) with identical flavor rise almost linearly with the number of valence quarks in hadrons, being consistent with the heavy quark symmetry in the heavy-quark limit.

   hep-phEPJC(2023)·20 citations
9. 09*

   A contact interaction model for the $\eta$ and ${\eta }^{\prime }$ mesons in a SDE-BSE approach to QCD: masses, decay widths and transition form factors

   Bilgai Almeida Zamora🇲🇽 · Enrique Carreon Martínez🇲🇽 · Jorge Segovia🇪🇸 · J.J. Cobos-Martínez🇲🇽

   We construct a contact interaction model for the $\eta$ and ${\eta }^{\prime }$ mesons in the SDE-BSE approach to QCD and compute several static properties of these mesons and their transition form factors. We find that this model gives an excellent description of the $\eta$ and ${\eta }^{\prime }$ static properties, namely their masses, decay width and decay constants. However, a contact interaction disagrees with experimental data for $Q^2$ greater than 2 GeV${}^2$, and produces transition form factors in conflict with perturbative QCD prediction. This is not surpring and the reasons for this are explained

   hep-phnucl-thPRD(2023)·10 citations
10. 10*

    Flow Away your Differences: Conditional Normalizing Flows as an Improvement to Reweighting

    Malte Algren🇨🇭 · Tobias Golling🇨🇭 · Manuel Guth🇨🇭 · Chris Pollard🇬🇧 · John Andrew Raine🇨🇭

    We present an alternative to reweighting techniques for modifying distributions to account for a desired change in an underlying conditional distribution, as is often needed to correct for mis-modelling in a simulated sample. We employ conditional normalizing flows to learn the full conditional probability distribution from which we sample new events for conditional values drawn from the target distribution to produce the desired, altered distribution. In contrast to common reweighting techniques, this procedure is independent of binning choice and does not rely on an estimate of the density ratio between two distributions. In several toy examples we show that normalizing flows outperform reweighting approaches to match the distribution of the target.We demonstrate that the corrected distribution closes well with the ground truth, and a statistical uncertainty on the training dataset can be ascertained with bootstrapping. In our examples, this leads to a statistical precision up to three times greater than using reweighting techniques with identical sample sizes for the source and target distributions. We also explore an application in the context of high energy particle physics.

    hep-phcs.LG18 citations
11. 11*

    Multi-photon decays of the Higgs boson at the LHC

    Samuel D. Lane🇰🇷 · Hye-Sung Lee🇰🇷 · Ian M. Lewis🇺🇸

    Many new physics scenarios predict multi-photon Higgs resonances. One such scenario is the dark axion portal model. The primary decay chain that we study is the Higgs to dark photon (${\gamma }_D$) pairs that subsequently decay into a photon ($\gamma$) and an axion-like particle ($a$). The axion-like particles then decay into photon pairs. Hence, the signal is a six-photon Higgs decay: $h\to {\gamma }_D{\gamma }_D\to 2\gamma 2a\to 6\gamma$. However, depending on the relevant kinematics, the photons can become well-collimated and appear as photon-jets (multiple photons that appear as a single photon in the detector) or $\xi$-jets (non-isolated multi-photon signals that do not pass the isolation criterion). These effects cause the true six-photon resonance to appear as other multi-photon signals, such as two and four photons. We classify the mass regions where two, four, and six-photon resonances dominate. The four-photon signal is particularly interesting. These events mainly occur when the photons from the axion-like particles are collimated into photon-jets. The decay of the dark photon is then ${\gamma }_D\to \gamma a\to \gamma +\gamma$-jet, which is an apparent violation of the Landau-Yang theorem. We show that current measurements of $h\to 2\gamma$ and searches for $h\to 4\gamma$ at the Large Hadron Collider (LHC) can limit $\mathrm{BR}(h\to {\gamma }_D{\gamma }_D)\lesssim 10^{-3}$. This model also motivates new searches for Higgs decays into six isolated photons or $\xi$-jets at the LHC. While there are currently no dedicated searches, we show that many of the Higgs to six isolated photons or $\xi$-jet events could pass two or three-photon triggers. That is, new physics could be found by reanalyzing existing data. These multi-photon signals provide excellent footing to explore new physics at the LHC and beyond.

    hep-ph6 citations
12. 12*

    Production and decays of 146 GeV flavons into $e\mu$ final state at the LHC

    Niko Koivunen🇪🇪 · Martti Raidal🇪🇪

    The CMS experiment at CERN has reported a possible signal for a resonance at 146 GeV decaying into the $e\mu$ final state which, presently, is the only experimental hint for lepton flavour violation in any low- and high-energy experiment. The Froggatt-Nielsen mechanism naturally predicts the existence of new scalars, the flavons, with flavour off-diagonal couplings. We study this framework in the context of the CMS result and find that the minimal, purely leptophilic model is too restricted to match the claimed signal. Thereafter we show how models with additional flavon couplings to quarks can explain the claimed signal while satisfying all the existing constraints on lepton flavour violation.

    hep-phJHEP(2023)·6 citations
13. 13*

    Discovering the Origin of Neutrino Masses at SHiP

    Seyda Ipek🇨🇦 · Douglas Tuckler🇨🇦

    In $U(1{)}_R$ extensions of supersymmetric models, the bino and its Dirac partner, the singlino, can play the role of right-handed neutrinos. The bino and the singlino form a pseudo-dirac pair, dubbed the `bi$\nu$o', which can generate Standard Model neutrino masses via the inverse seesaw mechanism. We investigate the prospects for detecting long-lived bi$\nu$os at SHiP, where GeV scale bi$\nu$os can be copiously produced in the decays of mesons. We show that SHiP can probe new regions of parameter space that are complementary to searches for the lepton flavor-violating decay $\mu \to e\gamma$. This scenario provides a well-motivated benchmark for future experiments of a right-handed neutrino that mixes with all Standard Model neutrinos, and is directly related to the generation of neutrino masses.

    hep-phPRD(2023)·3 citations
14. 14*

    The Flavor of QCD Axion Dark Matter

    Gonzalo Alonso-Álvarez🇨🇦 · James M. Cline🇨🇦 · Tianzhuo Xiao🇨🇦

    We argue that demanding a consistent cosmological history, including the absence of domain walls and strongly interacting relics at the Peccei-Quinn scale, singles out two concrete realizations of hadronic QCD axions as viable dark matter models. These realizations generally feature flavor-violating axion couplings to Standard Model quarks that are unsuppressed at low energies. As a consequence, experiments looking for flavor-violating hadronic processes involving the axion can be sensitive probes of QCD axion dark matter models. In particular, we show that the NA62 and KOTO experiments could detect the $K\to \pi +a$ decay for axions consistent with the observed dark matter abundance via the post-inflationary misalignment mechanism.

    hep-phastro-ph.COJHEP(2023)·24 citations
15. 15*

    Waiting for Precise Measurements of $\beta$ and $\gamma$

    Andrzej J. Buras🇩🇪

    During the last three decades the determination of the Unitarity Triangle (UT) was dominated by the measurements of its sides $R_b$ and $R_t$ through tree-level $B$ decays and the $\Delta M_d/\Delta M_s$ ratio, respectively, with some participation of the measurements of the angle $\beta$ through the mixing induced CP-asymmetries like $S_{\psi K_S}$ and ${\epsilon }_K$. However, as pointed out already in 2002 by Fabrizio Parodi, Achille Stocchi and the present author, the most efficient strategy for a precise determination of the apex of the UT, that is $(\bar{\varrho },\bar{\eta })$, is to use the measurements of the angles $\beta$ and $\gamma$. The second best strategy would be the measurements of $R_b$ and $\gamma$. However, in view of the tensions between different determinations of $|V_{ub}|$ and $|V_{cb}|$, that enter $R_b$, the $(\beta ,\gamma )$ strategy should be a clear winner once LHCb and Belle II will improve the measurements of these two angles. In this note we recall our finding of 2002 which should be finally realized in this decade through precise measurements of both angles by these collaborations. In this context we present two very simple formulae for $\bar{\varrho }$ and $\bar{\eta }$ in terms of $\beta$ and $\gamma$ which could be derived by high-school students, but to my knowledge never appeared in the literature on the UT, not even in our 2002 paper. We also emphasize the importance of precise measurements of both angles that would allow to perform powerful tests of the SM through numerous $|V_{cb}|$-independent correlations between $K$ and $B$ decay branching ratios $R_i(\beta ,\gamma )$ recently derived by Elena Venturini and the present author. The simple findings presented here will appear in a subsection of a much longer contribution to the proceedings of KM50 later this year. I exhibited them here so that they are not lost in the latter.

    hep-phhep-exhep-lat2 citations
16. 16*

    Prometheus: An Open-Source Neutrino Telescope Simulation

    Jeffrey Lazar🇺🇸 · Stephan Meighen-Berger🇦🇺 · Christian Haack🇩🇪 · David Kim🇺🇸 · Santiago Giner🇺🇸 · Carlos A. Argüelles🇺🇸

    Neutrino telescopes are gigaton-scale neutrino detectors comprised of individual light-detection units. Though constructed from simple building blocks, they have opened a new window to the Universe and are able to probe center-of-mass energies that are comparable to those of collider experiments. \prometheus{} is a new, open-source simulation tailored for this kind of detector. Our package, which is written in a combination of \texttt{C++} and \texttt{Python} provides a balance of ease of use and performance and allows the user to simulate a neutrino telescope with arbitrary geometry deployed in ice or water. \prometheus{} simulates the neutrino interactions in the volume surrounding the detector, computes the light yield of the hadronic shower and the out-going lepton, propagates the photons in the medium, and records their arrival times and position in user-defined regions. Finally, \prometheus{} events are serialized into a \texttt{parquet} file, which is a compact and interoperational file format that allows prompt access to the events for further analysis.

    ↳ hep-exastro-ph.HEastro-ph.IMhep-phComput.Phys.Commun.(2024)·17 citations
17. 17*

    Causality and stability in first-order conformal anisotropic hydrodynamics

    Fabio S. Bemfica🇧🇷 · Mauricio Martinez🇺🇸 · Masoud Shokri🇩🇪

    We formulate the first-order dissipative anisotropic hydrodynamical theory for a relativistic conformal uncharged fluid, which generalizes the Bemfica-Disconzi-Noronha-Kovtun first-order viscous fluid framework. Our approach maintains causal behavior in the nonlinear regime with or without general relativity coupling, and we derive and analyze the constraints on transport coefficients imposed by causality. We demonstrate the causal and stable behavior of our theory in specific cases, including the discussion of nonlinear causality as well as stability for linearized perturbations. We apply our newly developed first-order anisotropic theory to the Bjorken flow and show how causality and stability impose constraints on the behavior of the early-time attractor.

    ↳ hep-thhep-phnucl-thphysics.flu-dynPRD(2023)·6 citations
18. 18*

    Resonant generation of high-order harmonics in nonlinear electrodynamics

    Ilia Kopchinskii · Petr Satunin🇷🇺

    We study the process of resonant generation of high-order harmonics in a closed cavity in the model of vacuum nonlinear electrodynamics. Concretely, we study the possibility of resonant generation of the third harmonic induced by a single electromagnetic mode in a radiofrequency cavity, as well as resonant generation of a combined frequency mode induced by two pump modes (${\omega }_1$ and ${\omega }_2$). We explicitly show that the third harmonic as well as the $2{\omega }_1+{\omega }_2$ combined frequency mode are not resonantly amplified, while the $2{\omega }_1-{\omega }_2$ signal mode is amplified for certain cavity geometry. We discuss the process from the point of view of quantum theory.

    ↳ quant-phhep-phhep-thphysics.opticsPhys.Part.Nucl.Lett.(2023)·1 citation
19. 19*

    Revisiting constraints on the photon rest mass with cosmological fast radio bursts

    Bao Wang🇨🇳 · Jun-Jie Wei🇨🇳 · Xue-Feng Wu🇨🇳 · Martín López-Corredoira🇪🇸

    Fast radio bursts (FRBs) have been suggested as an excellent celestial laboratory for testing the zero-mass hypothesis of the photon. In this work, we use the dispersion measure (DM)--redshift measurements of 23 localized FRBs to revisit the photon rest mass $m_{\gamma }$. As an improvement over previous studies, here we take into account the more realistic probability distributions of DMs contributed by the FRB host galaxy and intergalactic medium (IGM) from the IllustrisTNG simulation. To better account for the systematic uncertainty induced by the choices of priors of cosmological parameters, we also combine the FRB data with the cosmic microwave background data, the baryon acoustic oscillation data, and type Ia supernova data to constrain the cosmological parameters and $m_{\gamma }$ simultaneously. We derive a new upper limit of $m_{\gamma }\le 3.8\times 10^{-51}\mathrm{kg}$, or equivalently $m_{\gamma }\le 2.1\times 10^{-15}eV/{\mathrm{c}}^2$ ($m_{\gamma }\le 7.2\times 10^{-51}\mathrm{kg}$, or equivalently $m_{\gamma }\le 4.0\times 10^{-15}eV/{\mathrm{c}}^2$) at $1\sigma$ ($2\sigma$) confidence level. Meanwhile, our analysis can also lead to a reasonable estimation for the IGM baryon fraction $f_{\mathrm{IGM}}=0.873_{-0.050}^{+0.061}$. With the number increment of localized FRBs, the constraints on both $m_{\gamma }$ and $f_{\mathrm{IGM}}$ will be further improved. A caveat of constraining $m_{\gamma }$ within the context of the standard $\Lambda$CDM cosmological model is also discussed.

    ↳ astro-ph.HEastro-ph.COhep-phJCAP(2023)·16 citations
20. 20*

    Determination of the neutron skin of ${}^{208}$Pb from ultrarelativistic nuclear collisions

    Giuliano Giacalone🇩🇪 · Govert Nijs🇺🇸 · Wilke van der Schee🇨🇭

    Emergent bulk properties of matter governed by the strong nuclear force give rise to physical phenomena across vastly different scales, ranging from the shape of atomic nuclei to the masses and radii of neutron stars. They can be accessed on Earth by measuring the spatial extent of the outer skin made of neutrons that characterises the surface of heavy nuclei. The isotope ${}^{208}$Pb, owing to its simple structure and neutron excess, has been in this context the target of many dedicated efforts. Here, we determine the neutron skin from measurements of particle distributions and their collective flow in ${}^{208}$Pb+${}^{208}$Pb collisions at ultrarelativistic energy performed at the Large Hadron Collider, which are sensitive to the overall size of the colliding ${}^{208}$Pb ions. By means of state-of-the-art global analysis tools within the hydrodynamic model of heavy-ion collisions, we infer a neutron skin $\Delta r_{np}=0.217\pm 0.058$ fm, consistent with nuclear theory predictions, and competitive in accuracy with a recent determination from parity-violating asymmetries in polarised electron scattering. We establish thus a new experimental method to systematically measure neutron distributions in the ground state of atomic nuclei.

    ↳ nucl-thastro-ph.HEhep-exhep-ph+1PRL(2023)·129 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.