Wed·May 25, 2022Wednesday·May 25, 2022

1. 01*

   Fully-charm and -bottom pentaquarks in a Lattice-QCD inspired quark model

   Gang Yang🇨🇳 · Jialun Ping🇨🇳 · Jorge Segovia🇪🇸

   The fully-charm and -bottom pentaquarks, \emph{i.e.} $cccc\bar{c}$ and $bbbb\bar{b}$, with spin-parity quantum numbers $J^P={\frac{1}{2}}^{-}$, ${\frac{3}{2}}^{-}$ and ${\frac{5}{2}}^{-}$, are investigated within a Lattice-QCD inspired quark model, which has already successfully described the recently announced fully-charm tetraquark candidate $X(6900)$, and has also predicted several other fully-heavy tetraquarks. A powerful computational technique, based on the Gaussian expansion method combined with a complex-scaling range approach, is employed to predict, and distinguish, bound, resonance and scattering states of the mentioned five-body system. Both baryon-meson and diquark-diquark-antiquark configurations, along with all of their possible color channels are comprehensively considered. Narrow resonances are obtained in each spin-parity channel for the fully-charm and -bottom systems. Moreover, most of them seems to be compact multiquarks whose wave-functions are dominated by either hidden-color baryon-meson or diquark-diquark-antiquark structure, or by the coupling between them.

   hep-phhep-exhep-latnucl-ex+1PRD(2022)·27 citations
2. 02*

   Resummed next-to-soft corrections to rapidity distribution of Higgs Boson to $\text{NNLO}+\overline{\text{NNLL}}$

   V. Ravindran🇮🇳 · Aparna Sankar🇮🇳 · Surabhi Tiwari🇮🇳

   We present the resumed predictions consisting of both soft-virtual(SV) as well as next-to-SV(NSV) threshold logarithms to all orders in perturbative QCD for the rapidity distribution of Higgs Boson till $\mathrm{NNLO}+\overline{\mathrm{NNLL}}$ accuracy at LHC. Using our recent formalism\cite{Ajjath:2020lwb}, the resummation is carried out in the double Mellin space by restricting the NSV contributions only from diagonal $gg$ channel. We perform the inverse Mellin ransformation using the minimal prescription procedure and match it with the corresponding fixed order results. We do a detailed analysis of the numerical impact of the resummed result. The K-factor values at different logarithmic accuracy suggest that the prediction for the rapidity distribution converges and becomes more reliable at $\mathrm{NNLO}+\overline{\mathrm{NNLL}}$ order. We further observed that the inclusion of resumed NSV contribution improves the renormalisation scale uncertainty at every order in perturbation theory. However, the uncertainty due to factorisation scale increases by the addition of resummed SV+NSV predictions to the fixed order rapidity distribution.

   hep-phPRD(2023)·12 citations
3. 03*

   Possible dibaryon production at $\bar{\mathrm{P}}$anda with a Lagrangian approach

   Yubing Dong🇨🇳 · Pengnian Shen🇨🇳

   In order to confirm the existence of the dibaryon state $d^{\ast }(2380)$ observed at WASA@COSY, we estimate the production of the possible dibaryon and anti-dibaryon pair $d^{\ast }{\bar{d}}^{\ast }$ at the energy region of the upcoming experiments at $\bar{\mathrm{P}}$anda. Based on some qualitative properties of $d^{\ast }$ extracted from the analysez in the non-relativistic quark model, the production cross section for this spin-3 particle pair are calculated with the help of an phenomenological effective relativistic and covariant Lagrangian approach.

   hep-phCPC(2022)·2 citations
4. 04*

   BSM Higgs Production at a Muon Collider

   Tao Han🇺🇸 · Shuailong Li🇺🇸 · Shufang Su🇺🇸 · Wei Su🇰🇷 · Yongcheng Wu🇺🇸

   The potential of the non-Standard Model heavy Higgs bosons in 2HDM at a muon collider is studied. The pair production of the non-SM Higgs bosons via the universal gauge interactions is the dominant mechanism once above the kinematic threshold. On the other hand, single Higgs boson production associated with a pair of heavy fermions is also important in the parameter region with enhanced Yukawa couplings. Both ${\mu }^{+}{\mu }^{-}$ annihilation channels and Vector Boson Fusion processes are considered, as well as radiative return $s$-channel production. Different types of 2HDMs can also be distinguishable for moderate and large values of $\tan \beta$.

   hep-ph14 citations
5. 05*

   Leptophilic Gauge Bosons at Lepton Beam Dump Experiments

   Takeo Moroi🇯🇵 · Atsuya Niki🇯🇵

   It has been recently known that we can use beams of future lepton colliders, the International Linear Collider (ILC), the Compact Linear Collider (CLIC), and the muon collider, for beam dump experiments if a shield and a detector are installed behind the beam dump. We study the prospect of searching for leptophilic gauge bosons (LGBs) in association with $U(1{)}_{L_e-L_{\mu }}$, $U(1{)}_{L_e-L_{\tau }}$, and $U(1{)}_{L_{\mu }-L_{\tau }}$ gauge symmetries at such lepton beam dump experiments. We perform a detailed calculation of the event rates of the LGB events, taking into account bremsstrahlung and pair-annihilation processes. We show that the lepton beam dump experiments at future lepton colliders can reach parameter regions which are not been covered.

   hep-phJHEP(2023)·11 citations
6. 06*

   Sterile Neutrino Portal Dark Matter in $\nu$THDM

   Ang Liu🇨🇳 · Feng-Lan Shao🇨🇳 · Zhi-Long Han🇨🇳 · Yi Jin🇨🇳 · Honglei Li🇨🇳

   In this paper, we propose the sterile neutrino portal dark matter in $\nu$THDM. This model can naturally generate tiny neutrino mass with the neutrinophilic scalar doublet ${\Phi }_{\nu }$ and sterile neutrinos $N$ around TeV scale. Charged under a $Z_2$ symmetry, one Dirac fermion singlet $\chi$ and one scalar singlet $\varphi$ are further introduced in the dark sector. The sterile neutrinos $N$ are the mediators between the DM and SM. Depending on the coupling strength, the DM can be either WIMP or FIMP. For the WIMP scenario, pair annihilation of DM into $NN$ is the key channel to satisfy various bounds, which could be tested at indirect detection experiments. For the FIMP scenario, besides the direct production of DM from freeze-in mechanism, contributions from late decay of NLSP is also important. When sterile neutrinos are heavier than the dark sector, NLSP is long-lived due to tiny mixing angle between sterile and light neutrinos. Constrains from free-streaming length, CMB, BBN and neutrino experiments are considered.

   hep-phEPJC(2023)·9 citations
7. 07*

   Eigenvector-eigenvalue identities and an application to flavor physics

   S. H. Chiu🇹🇼 · T. K. Kuo🇺🇸

   The eigenvector-eigenvalue identities are expanded to include general mixing parameters. Some simple relations are obtained and they reveal an intricate texture of connections between the eigenvalues and the mixing parameters. Permutation symmetry ($S_3\times S_3$) plays an indispensable role in our analysis. It is the guiding principle for the understanding of our results -- all of them are tensor equations under permutation.

   hep-phEPJC(2022)·2 citations
8. 08*

   Infrared-safe flavoured anti-$k_T$ jets

   Michal Czakon🇩🇪 · Alexander Mitov🇬🇧 · Rene Poncelet🇬🇧

   Flavour tagging is technically challenging on the experimental side. However, it suffers from a more fundamental problem from the theoretical point of view, in particular when implemented in fixed-order perturbation theory. It turns out that an infrared-safe definition of a flavoured jet is intricate due to the singularities induced by the emission of flavoured quark-anti-quark pairs of negligible energy. Although this issue has been addressed by a modification of the standard $k_T$ jet algorithm, the situation is not entirely satisfactory as most measurements rather use the anti-$k_T$ jet algorithm. In this work, we propose a flavour-aware infrared-safe modification of the anti-$k_T$ jet algorithm that is easy to implement within perturbative Monte Carlo frameworks and has minor impact on jet phenomenology when flavour tagging is not required. Besides the numerical verification of the infrared safety of the proposed algorithm at next-to-next-to-leading order, we also present results for the hadro-production of a lepton pair in association with a $b$-jet, and of a top-quark pair decaying into $b$-jets and leptons.

   hep-phhep-exJHEP(2023)·72 citations
9. 09*

   A model of pseudo-Nambu-Goldstone dark matter from a softly broken $SU(2)$ global symmetry with a $U(1)$ gauge symmetry

   Tomohiro Abe🇯🇵 · Yu Hamada🇯🇵

   A model of the pseudo-Nambu-Goldstone (pNG) dark matter (DM) is proposed. We assume that there is an $SU(2{)}_g$ global symmetry and a $U(1{)}_X$ gauge symmetry in the dark sector, and they are spontaneously broken into a $U(1{)}_D$ global symmetry after a scalar field develops a vacuum expectation value. We add a soft symmetry breaking term that breaks the $SU(2{)}_g$ global symmetry into the $U(1{)}_g$ global symmetry explicitly. Our model predicts a stable complex pNG particle under the $U(1{)}_D$ global symmetry. One of the virtues of the pNG DM models is that the models can explain the current null results in the direct detection experiments. The small momentum transfer suppresses the scattering amplitudes thanks to the low energy behavior of the Nambu-Goldstone boson. In our model, the soft symmetry breaking term is uniquely determined. This is the advantage of our model to some earlier works in which some soft symmetry breaking terms cannot be forbidden but are simply assumed to be absent to avoid the constraints from the direct detection experiments. We calculate the thermal relic abundance of the pNG DM and find that model can explain the measured value of the DM energy density under some constraints from the perturbative unitarity.

   hep-phPTEP(2023)·17 citations
10. 10*

    MSSM Under Higgs Factories

    Honglei Li🇨🇳 · Huayang Song🇨🇳 · Shufang Su🇺🇸 · Wei Su🇰🇷 · Jin Min Yang🇨🇳

    The high precision measurements of the Higgs mass and couplings at the future Higgs factories are sensitive to the parameter space of the Minimal Supersymmetric Standard Model (MSSM). Focused on the dominant stop sector contributions, we study the implication of the Higgs precision measurements on MSSM using multi-variable ${\chi }^2$ fit. The results show nice complementarity between the indirect searches at Higgs factories and the direct searches at the current LHC program.

    hep-ph1 citation
11. 11*

    The role of initial gluon emission in double $J/\psi$ production at central rapidities

    S. P. Baranov🇷🇺 · A. V. Lipatov🇷🇺 · A. A. Prokhorov🇷🇺

    We consider the process of double $J/\psi$ production in $pp$ collisions at the LHC in the framework of $k_T$-factorization approach. We focus on the gluon fragmentation mechanism which is related to multiple gluon emission in the initial state. The initial state emission is treated according to Catani-Ciafaloni-Fiorani-Marchesini evolution equation, and applies to both single and double parton scattering cases. We show the importance of fragmentation contributions to $J/\psi$ pair production and perform a comparison between theoretical predictions and the latest ATLAS data collected at $\sqrt{s}=8$ TeV. We find that the effects of multiple gluon emission are essential for both single- and multiparton interaction processes. Finally, we highlight the problem of correct choice of the factorization scale with respect to numerical stability of the calculations and the consistency with non-collinear evolution equations.

    hep-phPRD(2022)·5 citations
12. 12*

    CP-violating effects on gravitational waves in a complex singlet extension of the Standard Model with degenerate scalars

    Gi-Chol Cho🇯🇵 · Chikako Idegawa🇯🇵 · Eibun Senaha

    We examine CP-violating effects on electroweak phase transition (EWPT) in the standard model with a complex singlet scalar focusing particularly on a scenario where additional scalars have masses close to 125 GeV. Such a high mass degeneracy makes collider signatures in the scenario standard model like, and current experimental data cannot distinguish them from the standard model predictions. We utilize a simplified scalar potential to understand impacts of CP violation on EWPT qualitatively. Then, one-loop effective potential with a thermal resummation is employed for full numerical evaluations. As a phenomenological consequence, gravitational waves from the first-order EWPT are also evaluated. We find that the strength of the first-order EWPT would get weaker as the CP-violating effect becomes larger. As a result, gravitational wave amplitudes are diminished by the size of the CP violation. Future gravitational wave experiments may shed light on CP violation in the singlet scalar sector as well as the experimental blind spot due to the high mass degeneracy.

    hep-phPRD(2022)·9 citations
13. 13*

    Towards a Stringy Description for the $Q\bar{Q}q\bar{q}$-Quark System

    Oleg Andreev🇷🇺

    For the case of two light flavors we propose the stringy description of the system made of one heavy and one light quark-antiquark pair, with the aim of exploring the two lower-lying Born-Oppenheimer potentials as a function of a separation of the heavy quark-antiquark pair. Our analysis reveals three critical separations related to the processes of string reconnection, breaking and junction annihilation. In particular, for the ground state potential only the process of string reconnection matters. We find that a tetraquark state makes the dominant contribution to the potential of the first excited state at small separations, and this is the big difference with the $QQ\bar{q}\bar{q}$-quark system where it does so to the ground state potential. Another big difference is the emergence of the full diquark picture $[Qq][\bar{Q}\bar{q}]$ rather than the partial picture $QQ[\bar{q}\bar{q}]$ for the tetraquark state. On the other hand, the scales of string junction annihilation, below which the systems can be thought of mainly as the compact tetraquarks, are very close for both cases and become almost the same if the phenomenological rule $E_{QQ}=\frac{1}{2}{E}_{Q\bar{Q}}$ holds. The same is also true for the screening lengths whose values are in agreement with lattice QCD.

    hep-phhep-lathep-thnucl-thPRD(2022)·13 citations
14. 14*

    Exotic Higgs Decays in the Type-II 2HDMs at Current and Future pp Colliders

    Felix Kling🇩🇪 · Honglei Li🇨🇳 · Shuailong Li🇺🇸 · Adarsh Pyarelal🇺🇸 · Huayang Song🇨🇳 · Shufang Su🇺🇸 · Wei Su🇰🇷

    The exotic decay modes of non-Standard Model Higgses can serve as powerful search channels to explore the parameter space of extended Higgs sectors. In this Snowmass contribution, we illustrate this using the Two-Higgs Doublet Model (2HDM) as an example. We first review the current experimental constraints on the parameter space of a Type-II 2HDM arising from existing searches for the exotic Higgs decay mode $A/H\to HZ/AZ$. We then present the sensitivity of future colliders to discover addition Higgs bosons using the exotic decay channels $A\to HZ$, $A\to H^{\pm }{W}^{\mp }$ and $H^{\pm }\to H{W}^{\pm }$. We find that a 100 TeV collider can probe almost the entire region of the Type-II 2HDM parameter space that survives current theoretical and experimental constraints and would therefore be an ideal machine to search for heavier Higgses in hierarchical scalar sectors.

    hep-phhep-ex3 citations
15. 15*

    Leptoquark-assisted Singlet-mediated Di-Higgs Production at the LHC

    Arvind Bhaskar🇮🇳 · Debottam Das🇮🇳 · Bibhabasu De🇮🇳 · Subhadip Mitra🇮🇳 · Aruna Kumar Nayak🇮🇳 · Cyrin Neeraj🇮🇳

    At the LHC, the gluon-initiated processes are considered to be the primary source of di-Higgs production. However, in the presence of a new resonance, the light-quark initiated processes can also contribute significantly. In this paper, we look at the di-Higgs production mediated by a new singlet scalar. The singlet is produced in both quark-antiquark and gluon fusion processes through loops involving a scalar leptoquark and right-handed neutrinos. With benchmark parameters inspired from the recent resonant di-Higgs searches by the ATLAS collaboration, we examine the prospects of such a resonance in the TeV-range at the High-Luminosity LHC (HL-LHC) in the $b\bar{b}{\tau }^{+}{\tau }^{-}$ mode with a multivariate analysis. We obtain the $5\sigma$ and $2\sigma$ contours and find that a significant part of the parameter space is within the reach of the HL-LHC.

    hep-phPLB(2022)·14 citations
16. 16*

    Probing Left-Right Symmetry via Gravitational Waves from Domain Walls

    Debasish Borah🇮🇳 · Arnab Dasgupta🇺🇸

    We study the possibility of probing the scale of left-right symmetry breaking in the context of left-right symmetric models (LRSM). In LRSM, the right handed fermions transform as doublets under a newly introduced $SU(2{)}_R$ gauge symmetry. This, along with a discrete parity symmetry $\mathcal{P}$ ensuring identical gauge couplings of left and right sectors make the model left-right symmetric, providing a dynamical origin of parity violation in electroweak interactions via spontaneous symmetry breaking. The spontaneous breaking of $\mathcal{P}$ leads to the formation of domain walls in the early universe. These walls, if made unstable by introducing an explicit parity breaking term, generate gravitational waves (GW) with a spectrum characterized by the wall tension or the spontaneous $\mathcal{P}$ breaking scale, and the explicit $\mathcal{P}$ breaking term. Considering explicit $\mathcal{P}$ breaking terms to originate from Planck suppressed operators provides one-to-one correspondence between the scale of left-right symmetry and sensitivities of near future GW experiments. This is not only complementary to collider and low energy probes of TeV scale LRSM but also to GW generated from first order phase transition in LRSM with different spectral shape, peak frequencies as well as symmetry breaking scales.

    hep-phastro-ph.COPRD(2022)·20 citations
17. 17*

    The Higgs condensate as a quantum liquid: Comparison with the full Run 2 CMS data

    Paolo Cea🇮🇹

    We compare our proposal for an additional heavy Standard Model Higgs boson to the available full data set collected by the CMS detector during Run 2 at the Large Hadron Collider (LHC) corresponding to an integrated luminosity of 138 fb${}^{-1}$. The CMS Collaboration performed a search for a high mass Higgs boson decaying into a pair of W bosons in the dileptonic channel. Our analysis of the CMS data indicated the presence of a broad excess in the mass range 600 GeV - 800 GeV with respect to the expected Standard Model background with a rather significative statistical significance. We found that our theoretical proposal is in reasonable agreement with the experimental observations.

    hep-phhep-ex2 citations
18. 18*

    W-boson mass anomaly as a manifestation of spontaneously broken additional SU(2) global symmetry on a new fundamental scale

    S. S. Afonin🇷🇺

    Recently the CDF Collaboration has announced a new precise measurement of the $W$-boson mass $M_W$ that deviates from the Standard Model (SM) prediction by $7\sigma$. The discrepancy in $M_W$ is about ${\Delta }_W\simeq 70$ MeV and probably caused by a beyond the SM physics. Within a certain scenario of extension of the SM, we obtain the relation ${\Delta }_W\simeq \frac{3\alpha }{8\pi }{M}_W\simeq 70$ MeV, where $\alpha$ is the electromagnetic fine structure constant. The main conjecture is the appearance of longitudinal components of the $W$-bosons as the Goldstone bosons of a spontaneously broken additional $SU(2)$ global symmetry at distances much smaller than the electroweak symmetry breaking scale. We argue that within this scenario, the masses of charged Higgs scalars can get an electromagnetic radiative contribution which enhances the observed value of $M_{W^{\pm }}$ with respect to the usual SM prediction. Our relation for ${\Delta }_W$ follows from the known one-loop result for the corresponding effective Coleman-Weinberg potential in combination with the Weinberg sum rules.

    hep-phUniverse(2022)·8 citations
19. 19*

    $M_W$ helps select $Z^{\prime }$ models for $b\to s\ell \ell$ anomalies

    Ben Allanach🇬🇧 · Joe Davighi🇨🇭

    As shown in Ref. \cite{Allanach:2021kzj}, the Third Family Hypercharge ($Y_3$) Model changes the Standard Model prediction for $M_W$ whilst simultaneously explaining anomalies in $b\to s\ell \ell$ transitions via a heavy $Z^{\prime }$ gauge boson which is spawned by a spontaneously broken gauged $U(1{)}_{Y_3}$ symmetry. The 2022 CDF II measurement of $M_W$, which is far from the Standard Model prediction, somewhat disfavours the $Y_3$ model. Here, we generalise the gauge charge assignments to the anomaly-free combination $s{Y}_3+t(B_3-L_3)$ and show that incorporating the 2022 CDF II measurement of $M_W$ selects a viable domain of integers $s$ and $t$. For example, $s=1,t=-3$ yields a $p-$value of .12 in a two-parameter global fit to 277 electroweak and flavour changing $b$ data, much improving a SM $p-$value of $5\times 10^{-6}$.

    hep-phhep-exEPJC(2022)·17 citations
20. 20*

    Efficiently Exploring Multi-Dimensional Parameter Spaces Beyond the Standard Model

    Carlos A. Argüelles🇺🇸 · Nicolò Foppiani🇺🇸 · Matheus Hostert🇨🇦

    We propose a method to ease the challenges of exploring multi-dimensional parameter spaces in beyond-the-Standard Model theories. We evaluate the model likelihood for any choice of parameters by sampling the theory parameters intelligently and building a Kernel Density Estimator. By reducing the number of expensive Monte-Carlo simulations, this method provides a more efficient way to test complex theories. We illustrate our technique to set new limits on a short-lived heavy neutrino $N$, proposed as an explanation of anomalies in neutrino experiments. Using a search for lepton pairs in the T2K near detector, we find exclusion limits on the model parameters in a vast region of parameter space, fully exploiting the advantages of our new method. With a single Monte Carlo simulation, we obtain the differential event rate for arbitrary choices of model parameters, allowing us to cast limits on any slice of the model parameter space. We conclude that $N$ particles with lifetimes greater than $c{\tau }^0\gtrsim 3$cm are excluded by T2K data. We also derive model-independent constraints in terms of the total rate, lifetime, and $N$ mass and provide an approximated analytical formula. This method can be applied in other branches of physics to explore the landscape of theory parameters efficiently.

    hep-phhep-exPRD(2023)·11 citations
21. 21*

    NLO deflections for spinning particles and Kerr black holes

    Gabriel Menezes🇧🇷 · Matteo Sergola🇬🇧

    We employ the "KMOC" formalism of [1] to compute classical momentum deflections of spinning bodies with arbitrary spin orientations up to next-to-leading order (one loop). We do this in electrodynamics and gravity. The final result, valid for generic masses, is true for all spins at tree level and up to second (fourth) spin order for the electromagnetic (gravity) case at one loop. Furthermore, emphasis is given to the probe limit scenario where our results extend to all spin orders in the heavy source, even at next-to-leading order. We carry out our computations both using a unitarity based framework and Feynman diagrammatic approach which relies on scattering amplitudes computed on fixed backgrounds.

    ↳ hep-thgr-qchep-phJHEP(2022)·77 citations
22. 22*

    Accessing DEMP and DVCS at Backward Angles above the Resonance Region

    W. B. Li🇺🇸 · J. R. Stevens🇺🇸 · G. M. Huber🇨🇦

    The proposed measurement is a dedicated study to investigate the exclusive electroproduction process: 1H(e, e'p)X, in the backward angle above the resonance region. Here, the produced particle X (pi0 or gamma) is emitted 180 degrees opposite to the virtual photon momentum. This study will apply the well-known L/T separation method of the electroproduction process to this unexplored backward angle kinematics region. The available theoretical frameworks give parallel interpretations to the backward angle meson production at the proposed kinematics. According to the QCD GPD-like TDA model, backward meson production as the virtual-photon probes the transverse meson cloud structure inside of the nucleon; whereas the hadronic Regge based model describes backward meson production as the interference between nucleon exchange and the meson produced via re-scattering of the nucleon. Testing these two approaches is like testing the onset of quarks and gluon physics, i.e. going deeper into the structure of nucleon to probe its quark and gluon content. Combining knowledge from both frameworks has the potential to provide complementary knowledge to the forward angle physics programs and obtain new physics insights to study the QCD transition from meson-nucleon to quark-hadron degrees of freedom.

    ↳ nucl-exhep-ph1 citation
23. 23*

    Viability of quantum communication across interstellar distances

    Arjun Berera🇬🇧 · Jaime Calderón-Figueroa🇬🇧

    The possibility of achieving quantum communication using photons across interstellar distances is examined. For this, different factors are considered that could induce decoherence of photons, including the gravitational field of astrophysical bodies, the particle content in the interstellar medium, and the more local environment of the Solar System. The X-ray region of the spectrum is identified as the prime candidate to establish a quantum communication channel, although the optical and microwave bands could also enable communication across large distances. Finally, we discuss what could be expected from a quantum signal emitted by an extraterrestrial civilization, as well as the challenges for the receiver end of the channel to identify and interpret such signals.

    ↳ quant-phgr-qchep-phPRD(2022)·13 citations
24. 24*

    Gravity as a gapless phase and biform symmetries

    Kurt Hinterbichler🇺🇸 · Diego M. Hofman🇳🇱 · Austin Joyce🇺🇸 · Grégoire Mathys🇺🇸

    We study effective field theories (EFTs) enjoying (maximal) biform symmetries. These are defined by the presence of a conserved (electric) current that has the symmetries of a Young tableau with two columns of equal length. When these theories also have a topological (magnetic) biform current, its conservation law is anomalous. We go on to show that this mixed anomaly uniquely fixes the two-point function between the electric and magnetic currents. We then perform a Källén-Lehmann spectral decomposition of the current-current correlator, proving that there is a massless mode in the spectrum, whose masslessness is protected by the anomaly. Furthermore, the anomaly gives rise to a universal form of the EFT whose most relevant term, which resembles the linear Einstein action, dominates the infrared physics. As applications of this general formalism, we study the theories of a Galileon superfluid and linearized gravity. Thus, one can view the masslessness of the graviton as being protected by the anomalous biform symmetries. The associated EFT provides an organizing principle for gravity at low energies in terms of physical symmetries, and allows interactions consistent with linearized diffeomorphism invariance. These theories are not ultraviolet-complete, the relevant symmetries can be viewed as emergent, nor do they include the nonlinearities necessary to make them fully diffeomorphism invariant, so there is no contradiction with the expectation that quantum gravity cannot have any global symmetries.

    ↳ hep-thgr-qchep-phJHEP(2023)·57 citations
25. 25*

    Revealing the Milky Way's Most Recent Major Merger with a Gaia EDR3 Catalog of Machine-Learned Line-of-Sight Velocities

    Adriana Dropulic🇺🇸 · Hongwan Liu🇺🇸 · Bryan Ostdiek🇺🇸 · Mariangela Lisanti🇺🇸

    Machine learning can play a powerful role in inferring missing line-of-sight velocities from astrometry in surveys such as Gaia. In this paper, we apply a neural network to Gaia Early Data Release 3 (EDR3) and obtain line-of-sight velocities and associated uncertainties for ~92 million stars. The network, which takes as input a star's parallax, angular coordinates, and proper motions, is trained and validated on ~6.4 million stars in Gaia with complete phase-space information. The network's uncertainty on its velocity prediction is a key aspect of its design; by properly convolving these uncertainties with the inferred velocities, we obtain accurate stellar kinematic distributions. As a first science application, we use the new network-completed catalog to identify candidate stars that belong to the Milky Way's most recent major merger, Gaia-Sausage-Enceladus (GSE). We present the kinematic, energy, angular momentum, and spatial distributions of the ~450,000 GSE candidates in this sample, and also study the chemical abundances of those with cross matches to GALAH and APOGEE. The network's predictive power will only continue to improve with future Gaia data releases as the training set of stars with complete phase-space information grows. This work provides a first demonstration of how to use machine learning to exploit high-dimensional correlations on data to infer line-of-sight velocities, and offers a template for how to train, validate and apply such a neural network when complete observational data is not available.

    ↳ astro-ph.GAhep-phphysics.data-anMNRAS(2023)·1 citation
26. 26*

    Neutrino Emission from Luminous Fast Blue Optical Transients

    Ersilia Guarini🇩🇰 · Irene Tamborra🇩🇰 · Raffaella Margutti🇺🇸

    Mounting evidence suggests that Luminous Fast Blue Optical Transients (LFBOTs) are powered by a compact object, launching an asymmetric and fast outflow responsible for the radiation observed in the ultraviolet, optical, infrared, radio, and X-ray bands. Proposed scenarios aiming to explain the electromagnetic emission include an inflated cocoon, surrounding a jet choked in the extended stellar envelope. In alternative, the observed radiation may arise from the disk formed by the delayed merger of a black hole with a Wolf-Rayet star. We explore the neutrino production in these scenarios, i.e. internal shocks in a choked jet and interaction between the outflow and the circumstellar medium (CSM). If observed on-axis, the choked jet provides the dominant contribution to the neutrino fluence. Intriguingly, the IceCube upper limit on the neutrino emission inferred from the closest LFBOT, AT2018cow, excludes a region of the parameter space otherwise allowed by electromagnetic observations. After correcting for the Eddington bias on the observation of cosmic neutrinos, we conclude that the emission from an on-axis choked jet and CSM interaction is compatible with the detection of two track-like neutrino events observed by the IceCube Neutrino Observatory in coincidence with AT2018cow, and otherwise considered to be of atmospheric origin. While the neutrino emission from LFBOTs does not constitute the bulk of the diffuse background of neutrinos observed by IceCube, detection prospects of nearby LFBOTs with IceCube and the upcoming IceCube-Gen2 are encouraging. Follow-up neutrino searches will be crucial for unravelling the mechanism powering this emergent transient class.

    ↳ astro-ph.HEhep-phApJ(2022)·18 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.