Mon·May 30, 2022Monday·May 30, 2022

1. 01*

   $D^0\to \bar{p}{e}^{+}$ Form Factors in LCSR

   Anshika Bansal🇮🇳

   Baryon number is conserved in the Standard Model (SM) of particle physics. Baryon Number Violation (BNV) is one of the criteria to explain the matter anti-matter asymmetry of the universe. Various beyond the SM (BSM) scenarios motivate BNV. In that view, it becomes important to look for various BNV decays. \\ In this work, we consider the BNV decay of heavy charmed meson to anti-proton and positron. This decay proceeds via the dim-6 SM effective field theory (SMEFT) operator and involves 12 independent form factors. We give estimates for these form factors in the framework of Light Cone Sum Rules (LCSR). As the interpolation current for the proton state is not unique, we have considered different forms of proton interpolation current and discuss the effect of the choice of the interpolation current.

   hep-phhep-ex1 citation
2. 02*

   Light- and heavy-quark symmetries and the $Y(4230)$, $Y(4360)$, $Y(4500)$, $Y(4620)$ and $X(4630)$ resonances

   Fang-Zheng Peng🇨🇳 · Mao-Jun Yan🇨🇳 · Mario Sánchez Sánchez🇫🇷 · Manuel Pavon Valderrama🇨🇳

   The heavy hadron spectrum is constrained by symmetries, of which two of the most important ones are heavy-quark spin and SU(3)-flavor symmetries. Here we argue that in the molecular picture the $Y(4230)$ (or $Y(4260)$), the $Y(4360)$ and the recently discovered $Y(4500)$ and $Y(4620)$ vector-like resonances are linked by these two symmetries. By formulating a contact-range effective field theory for the $D{\bar{D}}_1$ and $D_s{\bar{D}}_{s1}$ family of S- and P-wave charmed meson-antimeson systems, we find that if the $Y(4230)$ were to be a pure $D{\bar{D}}_1$ molecular state, there would be a $D^{\ast }{\bar{D}}_1$ partner with a mass similar to the $Y(4360)$, a $D_s{\bar{D}}_{s1}$ partner with a mass close to the $Y(4500)$ and three $J=1,2$ $D_s^{\ast }{\bar{D}}_{s1}$ and $J=3$ $D_s^{\ast }{\bar{D}}_{s2}^{\ast }$ bound states with a mass in the vicinity of $4630\mathrm{MeV}$, of which the first one ($J=1$) might correspond with the $Y(4620)$. The previous predictions can in turn be improved by modifying the assumptions we have used to build the effective field theory. In particular, if we consider the closeness of the $D^{\ast }{\bar{D}}_1$-$D^{\ast }{\bar{D}}_2^{\ast }$ and $D_s^{\ast }{\bar{D}}_{s1}$-$D_s^{\ast }{\bar{D}}_{s2}^{\ast }$ thresholds and include the related coupled channel dynamics, we predict a $J=2$ positive C-parity state with a mass around $4650\mathrm{MeV}$. This hidden-strange and hidden-charm state might in turn be identified with the $X(4630)$ that has been discovered past year by the LHCb in the $J/\psi \varphi$ invariant mass distribution.

   hep-phhep-exhep-latnucl-thPRD(2023)·31 citations
3. 03*

   Production of light antinuclei in $pp$ collisions by dynamical coalescence and their fluxes in cosmic rays near earth

   Tianhao Shao🇨🇳 · Jinhui Chen🇨🇳 · Yu-Gang Ma🇨🇳 · Zhangbu Xu🇺🇸

   Light antinucleus yields are calculated in a multiphase transport model (AMPT) coupled with a dynamical coalescence model. The model is tuned to reproduce the transverse momentum and rapidity distributions of antiproton in $pp$ collisions at $\sqrt{\mathrm{s}}$ = 7.7 GeV to 7 TeV. By applying a widely used cosmic ray propagation model, the antinucleus fluxes near the earth are estimated over a broad range of kinetic energies. Our result on the antideuteron flux is consistent with the calculations in the literature, while our upper limit on the antihelium-3 flux sits in-between calculations in the field that span an order of magnitude in its value. This study suggests that further accurate estimation of secondary antihelium-3 flux could be improved with more ground-based experiments and model simulations. Most importantly, our value of antinucleus background from hadronic source is far below the projected sensitivity of AMS-02 with 5 years of integration time, which supports the idea of searching for new physics by measurements of light antinuclei in upcoming decade.

   hep-phnucl-exPRC(2022)·10 citations
4. 04*

   Heavy + heavy and heavy + light pseudoscalar to vector semileptonic transitions

   Hui-Yu Xing🇨🇳 · Zhen-Ni Xu🇨🇳 · Zhu-Fang Cui🇨🇳 · Craig D. Roberts🇨🇳 · Chang Xu🇨🇳

   Using a symmetry-preserving regularisation of a vector$\times$vector contact interaction (SCI), we complete a systematic treatment of twelve semileptonic transitions with vector meson final states: $D\to \rho$, $D_{(s)}\to K^{\ast }$, $D_s\to \varphi$, $B\to \rho$, $B_s\to K^{\ast }$, $B_{(s)}\to D_{(s)}^{\ast }$, $B_c\to B_{(s)}^{\ast },J/\psi ,D^{\ast }$; and thereby finalise a unified analysis of semileptonic decays of heavy+heavy and heavy+light pseudoscalar mesons to both pseudoscalar and vector meson final states. The analysis is marked by algebraic simplicity, few parameters, and the ability to consistently describe systems from Nambu-Goldstone modes to heavy+heavy mesons. Regarding the behaviour of the transition form factors, the SCI results compare well wherever sound experimental or independent theory analyses are available; hence, the SCI branching fraction predictions should be a reasonable guide. Considering the ratios $R(D_{(s)}^{(\ast )})$, $R(J/\psi )$, $R({\eta }_c)$, whose values are key tests of lepton universality in weak interactions, the SCI values agree with Standard Model predictions. The $B_{(s)}\to D_{(s)}^{\ast }$ transitions are used to predict the precursor functions that evolve into the universal Isgur-Wise function in the heavy-quark limit, with results that conform with those from other sources where such are available. The study also exposes effects on the transition form factors that flow from interference between emergent hadron mass from the strong interaction and Higgs boson couplings via current-quark masses, including flavour symmetry violation.

   hep-phhep-exhep-latnucl-ex+1EPJC(2022)·24 citations
5. 05*

   Recent developments and latest results from the xFitter project

   Francesco Giuli (on behalf of the xFitter Developers' Team)🇨🇭

   In this proceeding, the xFitter project is presented. xFitter is an open-source package that provides a framework for the determination of the parton distribution and fragmentation functions for many different kinds of analyses in Quantum Chromodynamics. xFitter version 2.2.0 has recently been released and offers an expanded set of tools and options. xFitter has been used for a number of analyses performed recently. An emphasis is given on the recently published study performed by the xFitter Developers' team of the pion fragmentation functions.

   hep-phhep-ex0 citations
6. 06*

   Light sterile neutrino and leptogenesis

   Ki-Young Jung🇰🇷 · Kim Siyeon🇰🇷

   We studied models of leptogenesis where three right-handed Majorana neutrinos are involved and the minimal-extended seesaw mechanism including an additional singlet field produces four light neutrinos. This study shows that the type of mass ordering and heavy Majorana scales can be determined by inputting the simplest orthogonal matrix into the Casas-Ibarra(CI) representation of seesaw. The CP asymmetry produced from the decays of heavy neutrinos and the dilution mass are predicted in terms of the mass and mixing elements of the fourth neutrino. Upon the choice of CI matrix, the existence of a light sterile neutrino is required to explain the high-energy lepton asymmetry in light of phenomenological measurements. Although there are several free parameters attributable to an additional neutrino, the model can be in part constrained by low-energy experiments such as sterile neutrino searches and neutrinoless double-beta decays, as well as the observed baryon asymmetry in the universe.

   hep-phJ.Korean Phys.Soc.(2022)·2 citations
7. 07*

   Core-collapse supernovae and neutrino properties

   Maria Cristina Volpe (APC, Paris)🇫🇷

   We highlight developments in the domain of supernova neutrinos. We discuss the importance of the future observation, by running and upcoming experiments, of the neutrino signals from the next supernova as well as of the diffuse supernova neutrino background.

   hep-phastro-ph.HEastro-ph.SRnucl-thJ.Phys.Conf.Ser.(2023)·1 citation
8. 08*

   Diffusion Monte Carlo calculations of fully-heavy compact hexaquarks

   J.M. Alcaraz-Pelegrina🇪🇸 · M. C. Gordillo🇪🇸

   We used a diffusion Monte Carlo technique to describe the properties of fully-heavy compact arrangements (no dibaryon molecules) including six quarks and no antiquarks within the framewok of a constituent quark model. Only arrangements whose wavefunctions were eigenvectors of $L^2$ with eigenvalue $\ell$ = 0 were taken into account, what means that we only considered the subset of all the possible color-spin combinations that make the total wavefunctions antisymmetric with respect to the interchange of any two quarks of the same type. This means arrangements with spin $S=0$ for $cccccc$, $bbbbbb$, $cccccb$, $bbbbbc$ and $cccbbb$ and spin $S=0,1,2$ for the $ccccbb$ and $bbbbcc$ hexaquarks. In all cases, the masses of the six-quark arrangements are larger that the ones corresponding to the sum of any of the two baryons we can split them into, but smaller that the ones for a set of six isolated quarks, i.e., all them are bound systems. The analysis of their structure indicates that all the hexaquarks considered in this work are compact objects, except the $cccbbb$, that appears to be a loose association of two baryons.

   hep-phnucl-thPRD(2022)·28 citations
9. 09*

   Non-exponential decay in classical stochastic processes with memory

   Maciej Rybczyński🇵🇱 · Zbigniew Włodarczyk🇵🇱

   The initial time-dependence of a state in circumstances where it makes transitions to, or decay to, a second state has been investigated. In classical stochastic processes, the observed time dependence of transition or decay proportional to $t^2$ is attributed to the noise with memory. In contrast to quantum mechanics, the quadratic form of initial decay is unable to decelerate the evolution of the system.

   hep-phmath.PRActa Phys.Polon.B(2023)·0 citations
10. 10*

    The dark dimension, the Swampland, and the origin of cosmic rays beyond the GZK barrier

    Luis A. Anchordoqui🇺🇸

    Very recently, it was pointed out that when basic ideas of the Swampland program are combined with the cosmological hierarchy problem (i.e. the smallness of the dark energy in Planck units) and together are confronted to experiment lead to the prediction of the existence of a single extra-dimension (dubbed the dark dimension) with characteristic length-scale in the micron range. We propose a feasible test procedure to probe the dark dimension using the highest energy cosmic rays.

    hep-phPRD(2022)·28 citations
11. 11*

    LFU ratios in B decays using Lattice QCD and Unitarity

    Guido Martinelli🇮🇹 · Manuel Naviglio🇮🇹 · Silvano Simula🇮🇹 · Ludovico Vittorio🇮🇹

    We present the results of the application of the unitarity-based Dispersion Matrix approach to semileptonic charged-current $B$ decays. This method allows to achieve a non-perturbative and completely model-independent determination of the hadronic form factors. Starting from lattice results available at large values of the momentum transfer, the behaviour of the form factors in their whole kinematical range is obtained without introducing any explicit parameterization of their momentum dependence. We will focus on the analysis of Lepton Flavour Universality by computing the $\tau /\mu$ ratios of the branching fractions of the $B\to D^{(\ast )}\ell \nu$ and $B\to \pi \ell \nu$ decays. The most important result is that, for the first time, the discrepancies between the SM expectation values and the measurements of the Lepton Flavour Universality ratios for the $B\to D^{(\ast )}\ell \nu$ decays are reduced at the 1.3$\sigma$ level for each of the two channels, separately.

    hep-phhep-exhep-latNuovo Cim.C(2022)·0 citations
12. 12*

    Saturation Correction to Projectile -- some $\mathcal{O}(g^5)$ results within LCPT

    Nahid Vasim🇮🇳

    We revisited the first saturation correction to projectile in nucleus-nucleus collisions \cite{Chirilli:2015tea} within diagrammatic light cone perturbation theory (LCPT). To get an analytic expression for the saturation correction in projectile authors in \cite{Chirilli:2015tea} calculated complete $\mathcal{O}(g^3)$ amplitudes, where the main results are given in transverse coordinate space. However to find the complete first saturation correction in the projectile, one needs to calculate both $\mathcal{O}(g^3)$ and $\mathcal{O}(g^5)$ gluon production amplitudes. We here present a detailed calculation of a sample graph at $\mathcal{O}(g^5)$ in diagrammatic light cone perturbation theory.

    hep-ph1 citation
13. 13*

    Analysis of FCNC ${\Xi }_{QQ}\to {\Lambda }_Q{l}^{+}{l}^{-}$ decay in light-cone sum rules

    T.M.Aliev · S.Bilmis · M.Savci

    The weak decays of doubly heavy ${\Xi }_{QQ}$ baryon induced by flavor changing $b\to d$ and $c\to u$ flavor changing neutral current within the light cone sum rules are studied. Using the parallel components of the light cone distribution amplitudes for ${\Lambda }_Q$ baryon, the sum rules are constructed and analyzed for the corresponding transition form factors. Having the results for the form factors, the corresponding branching ratios for ${\Xi }_{QQ}\to {\Lambda }_Q{l}^{+}{l}^{-}$ decays are estimated. While the branching ratio due to $b\to d$ transition is around $10^{-9}$, in $c\to u$ transition case, it is found as around $10^{-13}$. Hence, ${\Xi }_{bb}\to {\Lambda }_b{l}^{+}{l}^{-}$ decay has the potential of being discovered at LHCb. However, ${\Xi }_{bb}\to {\Lambda }_b{l}^{+}{l}^{-}$ is difficult to be measured due to the extremely small values of obtained branching ratio. Our results on the branching ratio are also compared with the results of the light-front approach.

    hep-phhep-latPRD(2022)·7 citations
14. 14*

    Is the $(g-2{)}_{\mu }$ anomaly a threat to Lepton Flavor Conservation?

    Julie Pagès🇨🇭

    Although the $(g-2{)}_{\mu }$ anomaly can be explained by New Physics (NP) involving only muons, a more general flavor structure is usually expected for NP operators in the Standard Model (SM) Effective Field Theory (SMEFT). In particular, if one wants to provide a combined explanation of several beyond the SM effects, like Lepton Flavor Universality (LFU) Violation, as indicated by the B anomalies, then a strong alignment of the NP operators in flavor space is required to satisfy the bounds from observables featuring Lepton Flavor Violation (LFV), like $\mu \to e\gamma$. We derived the tight bound of $10^{-5}$ on the flavor angle in the dipole operator in the charged-lepton mass basis in the SMEFT. We found that misalignment in several operators at high-scale could spoil the alignment at low-scale, through the Renormalization Group Evolution (RGE) of the SMEFT. In particular, it imposes constraints on some 4-fermions operators. We explored dynamical mechanisms as well as flavor symmetries to explain this flavor alignment, and illustrated the difficulty to reach it in an explicit NP model. If the $(g-2{)}_{\mu }$ anomaly is confirmed, the only natural explanation seems to lie in the individual lepton number conservation. If this accidental symmetry of the SM is also present in higher-order terms in the SMEFT, we are led to conclude that quark and lepton sectors behave quite differently beyond the SM. This proceeding is based on arXiv:2111.13724.

    hep-phNuovo Cim.C(2022)·0 citations
15. 15*

    On series and integral representations of some NRQCD master integrals

    M.A. Bezuglov🇷🇺 · A.V. Kotikov🇷🇺 · A.I. Onishchenko🇷🇺

    We consider new ways of obtaining series and integral representations for master integrals arising in the process of matching of QCD to NRQCD. The latter results are exact in space-time dimension $d$. In addition, we discuss series expansion of the obtained results at fixed values of $d$.

    hep-phJETP Lett.(2022)·7 citations
16. 16*

    Dark Matter Pollution in the Diffuse Supernova Neutrino Background

    Nicole F. Bell🇦🇺 · Matthew J. Dolan🇦🇺 · Sandra Robles🇬🇧

    The Hyper-Kamiokande (HyperK) experiment is expected to precisely measure the Diffuse Supernova Neutrino Background (DSNB). This requires that the backgrounds in the relevant energy range are well understood. One possible background that has not been considered thus far is the annihilation of low-mass dark matter (DM) to neutrinos. We conduct simulations of the DSNB signal and backgrounds in HyperK, and quantify the extent to which DM annihilation products can pollute the DSNB signal. We find that the presence of DM could affect the determination of the correct values of parameters of interest for DSNB physics, such as effective neutrino temperatures and star formation rates. While this opens the possibility of simultaneously characterising the DNSB and discovering dark matter via indirect detection, we argue that it would be hard to disentangle the two contributions due to the lack of angular information available at low energies.

    hep-phastro-ph.COastro-ph.HEhep-exJCAP(2022)·11 citations
17. 17*

    Relativistic variables for covariant, retardless wave equations

    M. De Sanctis🇨🇴

    A reduced form of the Dirac equation has been previously introduced and studied in the Center of Mass reference frame. In this work we show that this equation can be written in a covariant form in a generic reference frame by using specific momentum variables. These variables are also consistent with the retardless form of the interaction of the model.

    hep-phActa Phys.Polon.B(2022)·4 citations
18. 18*

    Scalar field damping at high temperatures

    Dietrich Bodeker🇩🇪 · Jan Nienaber🇩🇪

    The motion of a scalar field that interacts with a hot plasma, like the inflaton during reheating, is damped, which is a dissipative process. At high temperatures the damping can be described by a local term in the effective equation of motion. The damping coefficient is sensitive to multiple scattering. In the loop expansion its computation would require an all-order resummation. Instead we solve an effective Boltzmann equation, similarly to the computation of transport coefficients. For an interaction with another scalar field we obtain a simple relation between the damping coefficient and the bulk viscosity, so that one can make use of known results for the latter. The numerical prefactor of the damping coefficient turns out to be rather large, of order $10^4$.

    hep-phastro-ph.COPRD(2022)·17 citations
19. 19*

    Decaying warm dark matter revisited

    Emil Brinch Holm🇩🇰 · Thomas Tram🇩🇰 · Steen Hannestad🇩🇰

    Decaying dark matter models provide a physically motivated way of channeling energy between the matter and radiation sectors. In principle, this could affect the predicted value of the Hubble constant in such a way as to accommodate the discrepancies between CMB inferences and local measurements of the same. Here, we revisit the model of warm dark matter decaying non-relativistically to invisible radiation. In particular, we rederive the background and perturbation equations starting from a decaying neutrino model and describe a new, computationally efficient method of computing the decay product perturbations up to large multipoles. We conduct MCMC analyses to constrain all three model parameters, for the first time including the mass of the decaying species, and assess the ability of the model to alleviate the Hubble and ${\sigma }_8$ tensions, the latter being the discrepancy between the CMB and weak gravitational lensing constraints on the amplitude of matter fluctuations on an $8h^{-1}$ Mpc${}^{-1}$ scale. We find that the model reduces the $H_0$ tension from $\sim 4\sigma$ to $\sim 3\sigma$ and neither alleviates nor worsens the $S_8\equiv {\sigma }_8({\Omega }_m/0.3{)}^{0.5}$ tension, ultimately showing only mild improvements with respect to $\Lambda$CDM. However, the values of the model-specific parameters favoured by data is found to be well within the regime of relativistic decays where inverse processes are important, rendering a conclusive evaluation of the decaying warm dark matter model open to future work.

    ↳ astro-ph.COhep-phJCAP(2022)·24 citations
20. 20*

    Locality and Analyticity of the Crossing Symmetric Dispersion Relation

    Debapriyo Chowdhury🇮🇳 · Parthiv Haldar🇮🇳 · Ahmadullah Zahed🇮🇳

    This paper discusses the locality and analyticity of the crossing symmetric dispersion relation (CSDR). Imposing locality constraints on the CSDR gives rise to a local and fully crossing symmetric expansion of scattering amplitudes, dubbed as Feynman block expansion. A general formula is provided for the contact terms that emerge from the expansion. The analyticity domain of the expansion is also derived analogously to the Lehmann-Martin ellipse. Our observation of type-II super-string tree amplitude suggests that the Feynman block expansion has a bigger analyticity domain and better convergence.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2022)·13 citations
21. 21*

    Early Dark Energy from a Higher-dimensional Gauge Theory

    Kentaro Kojima🇯🇵 · Yuri Okubo🇯🇵

    The Hubble constant estimated from the CMB measurements shows large disagreement with the locally measured value. This inconsistency is called the Hubble tension and is vastly studied in recent years. Early Dark Energy (EDE) gives a few percent contribution to the total energy density of the universe only at an epoch before the recombination, and it is considered as a promising solution to the tension. A simple realization of EDE is given by dynamics of a scalar field, called the EDE scalar, and models including the EDE scalar are extensively studied in the literature. In this paper, we present a novel EDE scenario based on higher-dimensional gauge theories. An extra component of gauge fields associated with a compact extra dimension behaves as the EDE scalar at low-energy and has a periodic potential, which has a similar form as potentials for pseudo Nambu-Goldstone bosons (PNGB). In a five-dimensional U(1) gauge theory, we show that a scalar field that originates from the gauge field can give EDE through its dynamics in a PNGB type potential with a suitable choice of parameters in the theory. We focus on the scenario where EDE is explained by the scalar field and clarify constraints on the fundamental parameters of the gauge theory, such as the gauge coupling, the compactification scale, and the mass parameters for matter fields. We also find that a sufficient dilution of EDE requires non-trivial relations among U(1) charges of matter fields. With specific matter contents, we numerically solve the time evolution of the scalar field and confirm that its energy density behaves as an EDE. In our scenario, the parameters of the gauge theory and predicted properties of EDE are related to each other. Thus, the cosmological restrictions on the EDE properties provide insights into higher-dimensional gauge theories.

    ↳ astro-ph.COhep-phPRD(2022)·20 citations
22. 22*

    The ATLASpdf21 fit: a novel determination of proton Parton Distribution Functions using ATLAS data

    Francesco Giuli🇨🇭

    We present fits to determine Parton Distribution Functions using a diverse set of measurements from the ATLAS experiment at the LHC, including inclusive $W$ and $Z$ boson production, $t\bar{t}$ production, $W$+jets and $Z$+jets production, inclusive jet production and direct photon production. These ATLAS measurements are used in combination with deep-inelastic scattering data from the electron-proton collider HERA. Particular attention is paid to the correlation of systematic uncertainties within and between the various ATLAS data sets and to the impact of model, theoretical and parameterisation uncertainties.

    ↳ hep-exhep-ph0 citations
23. 23*

    Fundamental physics with ESPRESSO: Constraints on Bekenstein and dark energy models from astrophysical and local probes

    C. J. A. P. Martins🇵🇹 · S. Cristiani🇮🇹 · G. Cupani🇮🇹 · V. D'Odorico🇮🇹 · R. Génova Santos🇪🇸 · A. C. O. Leite🇵🇹 · C. M. J. Marques🇵🇹 · D. Milaković🇮🇹 · P. Molaro🇮🇹 · Michael T. Murphy🇮🇹 · N. J. Nunes🇵🇹 · Tobias M. Schmidt🇮🇹 and 12 other authors

    Dynamical scalar fields in an effective four-dimensional field theory are naturally expected to couple to the rest of the theory's degrees of freedom, unless some new symmetry is postulated to suppress these couplings. In particular, a coupling to the electromagnetic sector will lead to spacetime variations of the fine-structure constant, $\alpha$. Astrophysical tests of the space-time stability of $\alpha$ are therefore a powerful probe of new physics. Here we use ESPRESSO and other contemporary measurements of $\alpha$, together with background cosmology data, local laboratory atomic clock and Weak Equivalence Principle measurements, to place stringent constraints on the simplest examples of the two broad classes of varying $\alpha$ models: Bekenstein models and quintessence-type dark energy models, both of which are parametric extensions of the canonical $\Lambda$CDM model. In both cases, previously reported constraints are improved by more than a factor of ten. This improvement is largely due to the very strong local constraints, but astrophysical measurements can help to break degeneracies between cosmology and fundamental physics parameters.

    ↳ astro-ph.COgr-qchep-phPRD(2022)·11 citations
24. 24*

    Search for $\bar{b}\bar{b}us$ and $\bar{b}\bar{c}ud$ tetraquark bound states using lattice QCD

    Stefan Meinel🇺🇸 · Martin Pflaumer🇩🇪 · Marc Wagner🇩🇪

    We use lattice QCD to investigate the existence of strong-interaction-stable antiheavy-antiheavy-light-light tetraquarks. We study the $\bar{b}\bar{b}us$ system with quantum numbers $J^P=1^{+}$ as well as the $\bar{b}\bar{c}ud$ systems with quantum numbers $I(J^P)=0(0^{+})$ and $I(J^P)=0(1^{+})$. We carry out computations on five gauge-link ensembles with $2+1$ flavors of domain-wall fermions, including one at the physical pion mass. The bottom quarks are implemented using lattice nonrelativistic QCD, and the charm quarks using an anisotropic clover action. In addition to local diquark-antidiquark and local meson-meson interpolating operators, we include nonlocal meson-meson operators at the sink, which facilitates the reliable determination of the low-lying energy levels. We find clear evidence for the existence of a strong-interaction-stable $\bar{b}\bar{b}us$ tetraquark with binding energy $(-86\pm 22\pm 10)\text{MeV}$ and mass $(10609\pm 22\pm 10)\text{MeV}$. For the $\bar{b}\bar{c}ud$ systems we do not find any indication for the existence of bound states, but cannot rule out their existence either.

    ↳ hep-lathep-phPRD(2022)·49 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.