Mon·Aug 8, 2022Monday·August 8, 2022

1. 01*

   Fully-heavy hexaquarks in a constituent quark model

   Qi-Fang Lü🇨🇳 · Dian-Yong Chen🇨🇳 · Yu-Bing Dong🇨🇳

   In this work, we systematically investigate the mass spectra of fully-heavy hexaquarks within a constituent quark model by including the color Coulomb potential, linear confining potential, and spin-spin interactions. Our results show that all of the fully-heavy hexaquarks lie above the corresponding baryon-baryon thresholds, and thus no stable compact one exists. These states may subsist as resonances and decay into two fully-heavy baryons easily through the fall-apart mechanism, which can be searched in future experiments.

   hep-phhep-exnucl-ex15 citations
2. 02*

   Warm dark matter from a gravitational freeze-in in extra dimensions

   Arturo de Giorgi🇪🇸 · Stefan Vogl🇩🇪

   We study the freeze-in of gravitationally interacting dark matter in extra dimensions. Focusing on a minimal dark matter candidate that only interacts with the SM via gravity in a five-dimensional model we find that a large range of dark matter and Kaluza-Klein graviton masses can lead to the observed relic density. The preferred values of the masses and the strength of the interaction make this scenario very hard to test in terrestrial experiments. However, significant parts of the parameter space lead to warm dark matter and can be tested by cosmological and astrophysical observations.

   hep-phJHEP(2023)·23 citations
3. 03*

   Discover the GellMann-Okubo formula with machine learning

   Zhenyu Zhang🇨🇳 · Rui Ma🇨🇳 · Jifeng Hu🇨🇳 · Qian Wang🇨🇳

   Machine learning is a novel and powerful technology and has been widely used in various science topics. We demonstrate a machine-learning based approach built by a set of general metrics and rules inspired by physics. Taking advantages of physical constraints, such as dimension identity, symmetry and generalization, we succeed to rediscover the GellMann Okubo formula using a technique of symbolic regression. This approach can effectively find explicit solutions among user-defined observable, and easily extend to study on exotic hadron spectrum.

   hep-phChin.Phys.Lett.(2022)·14 citations
4. 04*

   Gluon gravitational form factors of protons from charmonium photoproduction

   Xiao-Yun Wang🇨🇳 · Fancong Zeng🇨🇳 · Quanjin Wang🇨🇳

   Inspired by the recent near-threshold $J/\psi$ photoproduction measurements, we discuss gluon gravitational form factors (GFFs) and internal properties of the proton. This work presents a complete analysis of the proton gluon GFFs connecting the gluon part of the energy-momentum tensor and the heavy quarkonium photoproduction. In particular, a global fitting of the $J/\psi$ differential and total cross section experimental data is used to determine the gluon GFFs as functions of the squared momentum transfer $t$. Combined with the quark contributions to the $D$-term form factor extracted from the deeply virtual Compton scattering experiment, the total $D$-term is obtained to investigate their applications in describing the proton mechanical properties. These studies provide a unique perspective on investigating the proton gluon GFFs and important information for enhancing QCD constraints on the gluon GFFs.

   hep-phCPC(2023)·11 citations
5. 05*

   Primordial lepton asymmetries in the precision cosmology era: Current status and future sensitivities from BBN and the CMB

   Miguel Escudero🇩🇪 · Alejandro Ibarra🇩🇪 · Victor Maura🇩🇪

   Using a new sample of extremely metal poor systems, the EMPRESS survey has recently reported a primordial helium abundance that is $3\sigma$ smaller than the prediction from the standard big bang nucleosynthesis (BBN) scenario. This measurement could be interpreted as a hint for a primordial lepton asymmetry in the electron neutrino flavor. Motivated by the EMPRESS results, we present a comprehensive analysis of the lepton asymmetry using measurements of the abundances of primordial elements, along with cosmic microwave background (CMB) data from Planck. Assuming that there is no dark radiation in our Universe, we find an electron neutrino chemical potential ${\xi }_{{\nu }_e}=0.043\pm 0.015$, which deviates from zero by $2.9\sigma$. If no assumption is made on the abundance of dark radiation in the Universe, the chemical potential is ${\xi }_{{\nu }_e}=0.046\pm 0.021$, which deviates from zero by $2.2\sigma$. We also find that this result is rather insensitive to the choice of nuclear reaction rates. If the true helium abundance corresponds to the EMPRESS central value, future CMB observations from the Simons Observatory and CMB-S4 will increase the significance for a nonzero lepton asymmetry to $4\sigma$ and $5\sigma$ respectively, assuming no dark radiation, or to $3\sigma$ when no assumption is made on the abundance of dark radiation.

   hep-phastro-ph.COPRD(2023)·60 citations
6. 06*

   A new constraint on primordial lepton flavour asymmetries

   Valerie Domcke🇨🇭 · Kohei Kamada🇯🇵 · Kyohei Mukaida🇯🇵 · Kai Schmitz🇩🇪 · Masaki Yamada🇯🇵

   A chiral chemical potential present in the early universe can source helical hypermagnetic fields through the chiral plasma instability. If these hypermagnetic fields survive until the electroweak phase transition, they source a contribution to the baryon asymmetry of the universe. In this letter, we demonstrate that lepton flavour asymmetries above $|\mu |/T\sim 9\times 10^{-3}$ trigger this mechanism even for vanishing total lepton number. This excludes the possibility of such large lepton flavour asymmetries present at temperatures above $10^6$ GeV, setting a constraint which is about two orders of magnitude stronger than the current CMB and BBN limits.

   hep-phastro-ph.COPRL(2023)·34 citations
7. 07*

   Exclusive photoproduction of $B_c^{\pm }$ and bottomonia pairs

   Sebastián Andrade🇨🇱 · Marat Siddikov🇨🇱 · Iván Schmidt🇨🇱

   In this paper we analyze the photoproduction of heavy quarkonia pairs which include $b$-quarks, such as $B_c^{+}{B}_c^{-}$-mesons or charmonium-bottomonium pairs. Compared to charmonia pair production, these channels get contributions only from some subsets of diagrams, and thus allow for a better theoretical understanding of different production mechanisms. In contrast to the production of hidden-flavor quarkonia, for the production of $B_c$-meson pairs there are no restrictions on internal quantum numbers in the suggested mechanisms. Using the Color Glass Condensate approach, we estimated numerically the production cross-sections in the kinematics of the forthcoming Electron-Proton collider and in the kinematics of ultraperipheral collisions at LHC. We found that the production of $J/\psi {\eta }_c$ and $B_c^{+}{B}_c^{-}$ meson pairs are the most promising channels for studies of quarkonia pair production.

   hep-phEPJC(2023)·2 citations
8. 08*

   Axionic Dirac seesaw and electroweak vacuum stability

   J. T. Penedo🇵🇹 · Yakefu Reyimuaji🇨🇳 · Xinyi Zhang🇨🇳

   We explore the connection between tree-level Dirac neutrino masses and axion physics in a scenario where the PQ symmetry enforces lepton number conservation perturbatively. Requiring that the PQ scale $f_a$ is the only heavy scale to play a role in neutrino mass generation, we are led to the construction of a KSVZ-type model where Dirac neutrino masses are inversely proportional to $f_a$, provided a real scalar triplet (zero hypercharge) is added to the SM scalar sector. We analyse this extended scalar sector, focusing on the stabilisation of the electroweak vacuum. The contribution of the triplet VEV to the $W$ mass may also be responsible for the recent hint of beyond-the-SM physics by the CDF collaboration.

   hep-phPRD(2022)·8 citations
9. 09*

   Inference of the sound speed and related properties of neutron stars

   Len Brandes🇩🇪 · Wolfram Weise🇩🇪 · Norbert Kaiser🇩🇪

   Information on the phase structure of strongly interacting matter at high baryon densities can be gained from observations of neutron stars and their detailed analysis. In the present work Bayesian inference methods are used to set constraints on the speed of sound in the interior of neutron stars, based on recent multi-messenger data in combination with limiting conditions from nuclear physics at low densities. Two general parametric representations are introduced for the sound speed $c_s$ in order to examine the independence with respect to choices for the parametrisation of Priors. Credible regions for neutron star properties are analysed, in particular with reference to the quest for possible phase transitions in cold dense matter. The evaluation of Bayes factors implies extreme evidence for a violation of the conformal bound, $c_s^2\le 1/3$, inside neutron stars. Given the presently existing data base, it can be concluded that the occurrence of a first-order phase transition in the core of even a two-solar-mass neutron star is unlikely, while a continuous crossover cannot be ruled out. At the same time it is pointed out that the discovery of a superheavy neutron star with a mass $M\sim 2.3-2.4M_{\odot }$ would strengthen evidence for a phase change in the deep interior of the star.

   ↳ nucl-thastro-ph.HEgr-qchep-phPRD(2023)·84 citations
10. 10*

    Electroweak nuclear radii constrain the isospin breaking correction to $V_{ud}$

    Chien-Yeah Seng🇩🇪 · Mikhail Gorchtein🇩🇪

    We lay out a novel formalism to connect the isospin-symmetry breaking correction to the rates of superallowed nuclear beta decays, ${\delta }_{\text{C}}$, to the isospin-breaking sensitive combinations of electroweak nuclear radii that can be accessed experimentally. We individuate transitions in the superallowed decay chart where a measurement of the neutron skin of a stable daughter even at a moderate precision could already help discriminating between models used to compute ${\delta }_{\text{C}}$. We review the existing experimental situation and make connection to the existing and future experimental programs.

    ↳ nucl-thhep-exhep-phnucl-exPLB(2023)·35 citations
11. 11*

    The reaction $\pi N\to \omega N$ in a dynamical coupled-channel approach

    Yu-Fei Wang🇩🇪 · Deborah Rönchen🇩🇪 · Ulf-G. Meißner🇩🇪 · Yu Lu🇨🇳 · Chao-Wei Shen🇩🇪 · Jia-Jun Wu🇨🇳

    A refined investigation on light flavor meson-baryon scatterings is performed using a dynamical coupled-channel approach, the Jülich-Bonn model, that respects unitartiy and analyticity constraints. The channel space of $\pi N$, $\pi \Delta$, $\sigma N$, $\rho N$, $\eta N$, $K\Lambda$ and $K\Sigma$ is extended by adding the $\omega N$ final state. The spectra of $N^{\ast }$ and $\Delta$ resonances are extracted in terms of complex poles of the scattering amplitudes, based on the result of a global fit to a worldwide collection of data, in the energy region from the $\pi N$ threshold to center-of-mass energy $z=2.3$ GeV. A negative value of the $\omega N$ elastic spin-averaged scattering length is extracted, questioning the existence of bound states of the $\omega$ meson in the nuclear matter.

    ↳ nucl-thhep-phnucl-exphysics.comp-phPRD(2022)·20 citations
12. 12*

    QCD in the cores of neutron stars

    Oleg Komoltsev🇳🇴

    I discuss why state-of-the art perturbative QCD calculations of the equation of state at large chemical potential that are reliable at asymptotically high densities constrain the same equation of state at neutron-star densities. I describe how these theoretical calculations affect the EOS at lower density. I argue that the ab-initio calculations in QCD offer significant information about the equation of state of the neutron-star matter, which is complementary to the current astrophysical observations.

    ↳ nucl-thastro-ph.HEhep-phActa Phys.Polon.Supp.(2023)·4 citations
13. 13*

    Deepest sensitivity to wavelike dark photon dark matter with superconducting radio frequency cavities

    Raphael Cervantes🇺🇸 · Jose Aumentado🇺🇸 · Caterina Braggio🇮🇹 · Bianca Giaccone🇺🇸 · Daniil Frolov🇺🇸 · Anna Grassellino🇺🇸 · Roni Harnik🇺🇸 · Florent Lecocq🇺🇸 · Oleksandr Melnychuk🇺🇸 · Roman Pilipenko🇺🇸 · Sam Posen🇺🇸 · Alexander Romanenko🇺🇸

    Wavelike, bosonic dark matter candidates like axions and dark photons can be detected using microwave cavities known as haloscopes. Traditionally, haloscopes consist of tunable copper cavities operating in the TM${}_{010}$ mode, but ohmic losses have limited their performance. In contrast, superconducting radio frequency (SRF) cavities can achieve quality factors of $\sim 10^{10}$, perhaps five orders of magnitude better than copper cavities, leading to more sensitive dark matter detectors. In this paper, we first derive that the scan rate of a haloscope experiment is proportional to the loaded quality factor $Q_L$, even if the cavity bandwidth is much narrower than the dark matter halo line shape. We then present a proof-of-concept search for dark photon dark matter using a nontunable ultrahigh quality SRF cavity. We exclude dark photon dark matter with kinetic mixing strengths of $\chi >1.5\times 10^{-16}$ for a dark photon mass of $m_{A^{\prime }}=5.35\mu$eV, achieving the deepest exclusion to wavelike dark photons by almost an order of magnitude.

    ↳ hep-exastro-ph.IMhep-phPRD(2024)·50 citations
14. 14*

    Constraining bosonic asymmetric dark matter with neutron star mass-radius measurements

    Nathan Rutherford🇺🇸 · Geert Raaijmakers🇳🇱 · Chanda Prescod-Weinstein🇺🇸 · Anna Watts🇳🇱

    Neutron stars can accumulate asymmetric dark matter (ADM) in their interiors, which affects the neutron star's measurable properties and makes compact objects prime targets to search for ADM. In this work, we use Bayesian inference to explore potential neutron star mass-radius measurements, from current and future x-ray telescopes, to constrain the bosonic ADM parameters for the case where bosonic ADM has accumulated in the neutron star interior. We find that the current uncertainties in the baryonic equation of state do not allow for constraints on the ADM parameter space to be made. However, we also find that ADM cannot be excluded and the inclusion of bosonic ADM in neutron star cores relaxes the constraints on the baryonic equation of state space. If the baryonic equation of state were more tightly constrained independent of ADM, we find that statements about the ADM parameter space could be made. In particular, we find that the high bosonic ADM particle mass ($m_{\chi }$) and low effective self-interaction strength ($g_{\chi }/m_{\varphi })$ regime is disfavored due to the observationally and theoretically motivated constraint that neutron stars must have at least a mass of $1{\mathrm{M}}_{\odot }$. However, within the remaining parameter space, $m_{\chi }$ and $g_{\chi }/m_{\varphi }$ are individually unconstrained. On the other hand, the ADM mass-fraction, i.e., the fraction of ADM mass inside the neutron star, can be constrained by such neutron star measurements.

    ↳ astro-ph.HEhep-phnucl-thPRD(2023)·94 citations
15. 15*

    Interpretable Uncertainty Quantification in AI for HEP

    Thomas Y. Chen🇺🇸 · Biprateep Dey🇺🇸 · Aishik Ghosh🇺🇸 · Michael Kagan🇺🇸 · Brian Nord🇺🇸 · Nesar Ramachandra🇺🇸

    Estimating uncertainty is at the core of performing scientific measurements in HEP: a measurement is not useful without an estimate of its uncertainty. The goal of uncertainty quantification (UQ) is inextricably linked to the question, "how do we physically and statistically interpret these uncertainties?" The answer to this question depends not only on the computational task we aim to undertake, but also on the methods we use for that task. For artificial intelligence (AI) applications in HEP, there are several areas where interpretable methods for UQ are essential, including inference, simulation, and control/decision-making. There exist some methods for each of these areas, but they have not yet been demonstrated to be as trustworthy as more traditional approaches currently employed in physics (e.g., non-AI frequentist and Bayesian methods). Shedding light on the questions above requires additional understanding of the interplay of AI systems and uncertainty quantification. We briefly discuss the existing methods in each area and relate them to tasks across HEP. We then discuss recommendations for avenues to pursue to develop the necessary techniques for reliable widespread usage of AI with UQ over the next decade.

    ↳ hep-excs.LGhep-phstat.ML17 citations
16. 16*

    How do the dynamics of the Milky Way -- Large Magellanic Cloud system affect gamma-ray constraints on particle dark matter?

    Christopher Eckner🇫🇷 · Francesca Calore🇫🇷 · Denis Erkal🇬🇧 · Sophia Lilleengen🇬🇧 · Michael S. Petersen🇫🇷

    Previous studies on astrophysical dark matter (DM) constraints have all assumed that the Milky Way's (MW) DM halo can be modelled in isolation. However, recent work suggests that the MW's largest dwarf satellite, the Large Magellanic Cloud (LMC), has a mass of 10-20$\%$ that of the MW and is currently merging with our Galaxy. As a result, the DM haloes of the MW and LMC are expected to be strongly deformed. We here address and quantify the impact of the dynamical response caused by the passage of the LMC through the MW on the prospects for indirect DM searches. Utilising a set of state-of-the-art numerical simulations of the evolution of the MW-LMC system, we derive the DM distribution in both galaxies at the present time based on the Basis Function Expansion formalism. Consequently, we build $J$-factor all-sky maps of the MW-LMC system in order to study the impact of the LMC passage on gamma-ray indirect searches for thermally produced DM annihilating in the outer MW halo as well as within the LMC halo standalone. We conduct a detailed analysis of 12 years of Fermi-LAT data that incorporates various large-scale gamma-ray emission components and we quantify the systematic uncertainty associated with the imperfect knowledge of the astrophysical gamma-ray sources. We find that the dynamical response caused by the LMC passage can alter the constraints on the velocity-averaged annihilation cross section for weak scale particle DM at a level comparable to the existing observational uncertainty of the MW halo's density profile and total mass.

    ↳ astro-ph.HEastro-ph.GAhep-phMNRAS(2023)·6 citations
17. 17*

    Have Pulsar Timing Arrays detected the Hot Big Bang? Gravitational Waves from Strong First Order Phase Transitions in the Early Universe

    Katherine Freese🇺🇸 · Martin Wolfgang Winkler🇺🇸

    The origins of matter and radiation in the universe lie in a Hot Big Bang. We present a number of well-motivated cosmologies in which the Big Bang occurs through a strong first order phase transition -- either at the end of inflation, after a period of kination ("Kination-Induced Big Bang"), or after a second period of vacuum-domination in the early universe ("Supercooled Big Bang"); we also propose a "Dark Big Bang" where only the dark matter in the Universe is created in a first-order phase transition much after inflation. In all of these scenarios, the resulting gravitational radiation can explain the tentative signals reported by the NANOGrav, Parkes and European Pulsar Timing Array experiments if the reheating temperature of the Hot Big Bang, and correspondingly the energy scale of the false vacuum, falls in the range $T_{\ast }\sim {\rho }_{\mathrm{vac}}^{1/4}$= MeV--100 GeV. All the same models at higher reheating temperatures will be of interest to upcoming ground- and space-based interferometer searches for gravitational waves at larger frequency.

    ↳ astro-ph.COhep-phhep-thPRD(2022)·37 citations
18. 18*

    Overcoming exponential scaling with system size in Trotter-Suzuki implementations of constrained Hamiltonians: 2+1 U(1) lattice gauge theories

    Dorota M. Grabowska🇨🇭 · Christopher Kane🇺🇸 · Benjamin Nachman🇺🇸 · Christian W. Bauer🇺🇸

    For many quantum systems of interest, the classical computational cost of simulating their time evolution scales exponentially in the system size. At the same time, quantum computers have been shown to allow for simulations of some of these systems using resources that scale polynomially with the system size. Given the potential for using quantum computers for simulations that are not feasible using classical devices, it is paramount that one studies the scaling of quantum algorithms carefully. This work identifies a term in the Hamiltonian of a class of constrained systems that naively requires quantum resources that scale exponentially in the system size. An important example is a compact U(1) gauge theory on lattices with periodic boundary conditions. Imposing the magnetic Gauss' law a priori introduces a constraint into that Hamiltonian that naively results in an exponentially deep circuit. A method is then developed that reduces this scaling to polynomial in the system size, using a redefinition of the operator basis. An explicit construction of the matrices defining the change of operator basis, as well as the scaling of the associated computational cost, is given.

    ↳ quant-phhep-lathep-ph39 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.