Thu·Dec 2, 2021Thursday·December 2, 2021

1. 01*

   Saha equilibrium for metastable bound states and dark matter freeze-out

   Tobias Binder🇯🇵 · Anastasiia Filimonova🇳🇱 · Kalliopi Petraki🇫🇷 · Graham White🇯🇵

   The formation and decay of metastable bound states can significantly decrease the thermal-relic dark matter density, particularly for dark matter masses around and above the TeV scale. Incorporating bound-state effects in the dark matter thermal decoupling requires in principle a set of coupled Boltzmann equations for the bound and unbound species. However, decaying bound states attain and remain in a quasi-steady state. Here we prove in generality that this reduces the coupled system into a single Boltzmann equation of the standard form, with an effective cross-section that describes the interplay among bound-state formation, ionisation, transitions and decays. We derive a closed-form expression for the effective cross-section for an arbitrary number of bound states, and show that bound-to-bound transitions can only increase it. Excited bound levels may thus decrease the dark matter density more significantly than otherwise estimated. Our results generalise the Saha ionisation equilibrium to metastable bound states, potentially with applications beyond the dark matter thermal decoupling.

   hep-phastro-ph.COPLB(2022)·30 citations
2. 02*

   New physics in triboson event topologies

   Linda M. Carpenter🇺🇸 · Matthew J. Smylie🇺🇸 · Jesus Manuel Caridad Ramirez🇺🇸 · Cameron McDowell🇺🇸 · Daniel Whiteson🇺🇸

   We present a study of the sensitivity to models of new physics of proton collisions resulting in three electroweak bosons. As a benchmark, we analyze models in which an exotic scalar field $\varphi$ is produced in association with a gauge boson ($V=\gamma$ or $Z$). The scalar then decays to a pair of bosons, giving the process $pp\to \varphi V\to V^{\prime }V"V$. We interpret our results in a set of effective field theories where the exotic scalar fields couple to the Standard Model through pairs of electroweak gauge bosons. We estimate the sensitivity of the LHC and HL-LHC datasets and find sensitivity to cross sections in the 10 fb -- 0.5 fb range, corresponding to scalar masses of 500 GeV to 2 TeV and effective operator coefficients up to 35 TeV.

   hep-phPRD(2022)·10 citations
3. 03*

   Impact of $Z\to {\eta }_{c,b}+g+g$ on the inclusive ${\eta }_{c,b}$ meson yield in $Z$-boson decay

   Zhan Sun🇨🇳 · Xuan Luo🇨🇳 · Ying-Zhao Jiang🇨🇳

   In this paper, we carry out the next-to-leading-order QCD corrections to $Z\to {\eta }_Q+g+g(Q=c,b)$ (labeled as $gg$) through the color-singlet (CS) state of $Q\bar{Q}{[}^1{S}_0^{[1]}]$, with the aim of assessing the impact of this process on $Z$ bosons decaying into inclusive ${\eta }_Q$. We find that the QCD corrections to the $gg$ process can notably enhance its leading-order results, especially for the ${\eta }_c$ case, which would then greatly increase the existing predictions of ${\Gamma }_{Z\to {\eta }_Q+X}$ given by the CS-dominant process $Z\to {\eta }_Q{[}^1{S}_0^{[1]}]+Q+\bar{Q}$. Moreover, with these significant QCD corrections, the $gg$ process would exert crucial influence on the CS-predicted ${\eta }_Q$ energy distributions. In conclusion, in the CS studies of $Z\to {\eta }_Q+X$, besides $Z\to {\eta }_Q{[}^1{S}_0^{[1]}]+Q+\bar{Q}$, $Z\to {\eta }_Q{[}^1{S}_0^{[1]}]+g+g$ can provide phenomenologically indispensable contributions as well.

   hep-phPRD(2022)·4 citations
4. 04*

   Role of the effective range in the weak-binding relation

   Tomona Kinugawa🇯🇵 · Tetsuo Hyodo🇯🇵

   We study the range correction in the weak-binding relation, which relates the internal structure of hadrons with the scattering length and the binding energy. Utilizing the effective field theories, we show that the effective range originates from the derivative coupling interaction as well as from the channel coupling to the bare state, and that the different contributions are not distinguishable. By examining the compositeness in the effective field theories, it is demonstrated that the effective range induces the finite range correction for the weak-binding relation in addition to the previously known contributions. We thus propose to include the range correction in the uncertainty terms of the weak-binding relation.

   hep-phnucl-thEPJ Web Conf.(2022)·16 citations
5. 05*

   Exploring $HVV$ amplitudes with $CP$ violation by decomposition and on-shell scattering amplitude methods

   Ke-Yao Feng🇨🇳 · Xia Wan🇨🇳 · You-Kai Wang🇨🇳 · Chao Wu🇨🇳

   $CP$ violation may play an important role in Baryogenesis in early universe, and should be examined at colliders comprehensively. We study $CP$ properties of $HVV$ vertexes between Higgs and gauge boson pairs with defining a $CP$ violation phase angle $\xi$, which indicates the mixture of $CP$-even and $CP$-odd Higgs states in $HVV$ in new physics. A series of $HVV$ amplitudes $H\to \gamma \gamma ,H\to \gamma V\to \gamma \ell \ell$, and $H\to VV\to 4\ell$ with $CP$ phase angle are studied systematically, which explains explicitly why $CP$ violation could only be probed in $4\ell$ process independently. We get a novel amplitude decomposition relation which illustrates if two preconditions (multilinear momentum dependent vertexes and current $J_{\mu }$ of $V\to {\ell }^{+}{\ell }^{-}$ is formally proportional to a photon's polarization vector) are satisfied, an high-point amplitude can be decomposed into a summation of a series of low-point amplitudes. As a practical example, the amplitude of $H\to \gamma V\to \gamma \ell \ell$, and $H\to VV\to 4\ell$ processes can be decomposed into summation of many $H\to \gamma \gamma$ amplitudes. Meanwhile, we calculate these amplitudes in the framework of on-shell scattering amplitude method, with considering both massless and massive vector gauge bosons with $CP$ violation phase angle. The above two approaches provides consistent results and exhibit clearly the $CP$ violation $\xi$ dependence in the amplitudes.

   hep-phhep-thCPC(2023)·3 citations
6. 06*

   Charmonium Triangular Flow in High Energy Nuclear Collisions

   Jiaxing Zhao🇨🇳 · Baoyi Chen🇨🇳 · Pengfei Zhuang🇨🇳

   We calculate, for the first time, $J/\psi$ triangular flow in high energy nuclear collisions. The charmonium motion in medium is controlled by a transport equation with loss and gain terms, and the evolution of the hot medium is governed by a single-shot hydrodynamic equation with a triangularly deformed initial condition. In comparison with the elliptic flow $v_2$, the triangular flow $v_3$ comes almost completely from the charmonium regeneration in the quark gluon plasma and therefore is more sensitive to the medium properties.

   hep-phnucl-thPRC(2022)·17 citations
7. 07*

   Charmless Quasi-two-body $B$ Decays in Perturbative QCD Approach: Taking $B\to K(\mathcal{R}\to )K^{+}{K}^{-}$ As Examples

   Wen-Feng Liu🇨🇳 · Zhi-Tian Zou🇨🇳 · Ying Li🇨🇳

   Three-body $B$ decays not only significantly broaden the study of $B$ meson decay mechanisms, but also provide information of resonant particles. Because of complicate dynamics, it is very hard for us to study the whole phase space in a specific approach. In this review, we take $B\to K(\mathcal{R}\to )K^{+}{K}^{-}$ decays as examples and show the application of the perturbative QCD (PQCD) approach in studying the quasi-two-body $B$ decays, where two particles move collinearly with large energy and the bachelor one recoils back. To describe the dynamics of two collinear particles, the ($S$, $P$ and $D$)-wave functions of kaon-pair with different waves are introduced. By keeping the transverse momenta, all possible diagrams including the hard spectator diagrams and annihilation ones can be calculated in PQCD approach. Most results are well consistent with the current measurements from BaBar, Belle and LHCb experiments. Moreover, under the narrow-width approximation we can extract the branching fractions of the two-body decays involving the resonant states, and also predict the branching fractions of the corresponding quasi-two-body decays $B\to K(\mathcal{R}\to ){\pi }^{+}{\pi }^{-}$. All prediction are expected to be tested in the ongoing LHCb and Belle-II experiments.

   hep-phhep-exAdv.High Energy Phys.(2022)·9 citations
8. 08*

   Perturbative and non-perturbative effects in ultraperipheral production of lepton pairs

   I.M. Dremin🇷🇺

   Perturbative and non-perturbative terms of the cross sections of ultraperipheral production of lepton pairs in ion collisions are taken into account. It is shown that production of low-mass $e^{+}{e}^{-}$ pairs is strongly enhanced (compared to perturbative estimates) due to the non-perturbative Sommerfeld-Gamow-Sakharov (SGS) factor. Coulomb attraction of the non-relativistic components of those pairs leads to the finite value of their mass distribution at lowest masses. Their annihilation can result in the increased intensity of 511 keV photons. It can be recorded at the NICA collider and is especially crucial in astrophysical implications regarding the 511 keV line emitted from the Galactic center. The analogous effect can be observed in lepton pairs production at LHC. Energy spectra of lepton pairs created in ultraperipheral nuclear collisions and their transverse momenta are calculated.

   hep-phastro-ph.HEhep-exnucl-ex+10 citations
9. 09*

   $\frac{|V_{ub}|}{|V_{cb}|}$ and Quest for New Physics

   Anshika Bansal🇮🇳 · Namit Mahajan🇮🇳 · Dayanand Mishra🇮🇳

   Charged current semi-leptonic decays of $B$-meson are important for a precise determination of the CKM elements. The CKM elements $|V_{ub}|$ and $|V_{cb}|$ show a discrepancy between the exclusive and inclusive determinations. These determinations are however masked with hadronic and other uncertainties, and thus can't be unambiguously taken as implying new physics. In the present study, we propose a new observable: the ratio of these two CKM elements, $R_V\equiv \frac{|V_{ub}|}{|V_{cb}|}$, which is found to receive negligible corrections due to hadronic as well as QED effects. Interestingly, $R_V$ as constructed from exclusive determinations of $|V_{ub}|$ and $|V_{cb}|$ agrees quite well with that constructed from the inclusive determinations of these CKM elements. Hence, we propose that $R_V$ is a better and cleaner observable, and can serve as an excellent tool for the test of the Standard Model. We also provide an example of its probing power.

   hep-phhep-exJHEP(2022)·5 citations
10. 10*

    Short-baseline oscillation scenarios at JUNO and TAO

    V.S. Basto-Gonzalez🇨🇴 · D.V. Forero🇨🇴 · C. Giunti🇮🇹 · A.A. Quiroga🇧🇷 · C.A. Ternes🇮🇹

    We study the sensitivity of JUNO and TAO to the oscillations induced by two well-motivated scenarios beyond the standard model: Large Extra Dimensions (LED) and light sterile neutrinos in the context of 3+1 neutrino mixing. We find that JUNO+TAO can set competitive bounds on the parameter space of each scenario. In particular, we find that JUNO+TAO can be competitive with MINOS, DUNE or KATRIN in the context of LED. If LED are present in nature, we show that the parameters could be measured with a similar precision as the standard oscillation parameters. We also show that JUNO+TAO can test nearly all of the parameter space preferred by Gallium experiments in the context of 3+1 mixing. Finally, we discuss the possibility to distinguish the two scenarios from each other.

    hep-phhep-exPRD(2022)·28 citations
11. 11*

    Modular symmetry in the SMEFT

    Tatsuo Kobayashi🇯🇵 · Hajime Otsuka🇯🇵 · Morimitsu Tanimoto🇯🇵 · Kei Yamamoto🇯🇵

    We study the modular symmetric standard-model effective field theory. We employ the stringy Ansatz on coupling structure that 4-point couplings $y^{(4)}$ of matter fields are written by a product of 3-point couplings $y^{(3)}$ of matter fields, i.e., $y^{(4)}=y^{(3)}{y}^{(3)}$. In this framework, we discuss the flavor structure of bilinear fermion operators and 4-fermion operators, where the holomorphic and anti-holomorphic modular forms appear. From the Ansatz, the $A_4$ modular-invariant semileptonic four-fermion operator $[{\bar{E}}_R\Gamma E_R][{\bar{D}}_R\Gamma D_R]$ does not lead to the flavor changing (FC) processes since this operator would be constructed in terms of gauge couplings $g$ as $y^{(3)}\sim g$. The chirality flipped bilinear operator $[{\bar{D}}_R\Gamma D_L]$ also does not lead FC if the mediated mode corresponds to the Higgs boson $H_d$. In this case, the flavor structure of this operator is the exactly same as the mass matrix. On the other hand, if the flavor structure of the operator is not the exactly same as the mass matrix, the situation would change drastically. Then, we obtain the non-trivial relations of FC transitions at nearby fixed points $\tau =i,\omega ,i\infty$, which are testable in the future. As an application, we discuss the relations of the lepton flavor violation processes $\mu \to e\gamma ,\tau \to \mu \gamma$ and $\tau \to e\gamma$ at nearby ${\tau }_e=i$, where the successful lepton mass matrix was obtained. We also study the flavor changing 4-quark operators in the $A_4$ modular symmetry of quarks. As a result, the minimal flavor violation could be realized by taking relevant specific parameter sets of order one.

    hep-phhep-thPRD(2022)·50 citations
12. 12*

    Sterile neutrino dark matter in a U(1) extension of the standard model

    Károly Seller🇭🇺

    We explore the possibilities of dark matter production in a U(1) extension of the standard model, also called the super-weak model. The freeze-in and freeze-out mechanisms are described in detail, assuming the lightest sterile neutrino in the model as the dark matter candidate. In both scenarios we present the favoured parameter space on the plane of super-weak coupling versus the new gauge boson mass. We discuss the experimental constraints limiting each case and outline possibilities of detection.

    hep-phastro-ph.COActa Phys.Polon.Supp.(2022)·1 citation
13. 13*

    Axion Effective Action

    Jérémie Quevillon🇫🇷 · Christopher Smith🇫🇷 · Pham Ngoc Hoa Vuong🇫🇷

    In this paper, we discuss the construction of Effective Field Theories (EFTs) in which a chiral fermion, charged under both gauge and global symmetries, is integrated out. Inspired by typical axion models, these symmetries can be spontaneously broken, and the global ones might also be anomalous. In this context, particular emphasis is laid on the derivative couplings of the Goldstone bosons to the fermions, as these lead to severe divergences and ambiguities when building the EFT. We show how to precisely solve these difficulties within the path integral formalism, by adapting the anomalous Ward identities to the EFT context. Our results are very generic, and when applied to axion models, they reproduce the non-intuitive couplings between the massive SM gauge fields and the axion. Altogether, this provides an efficient formalism, paving the way for a systematic and consistent methodology to build entire EFTs involving anomalous symmetries, as required for axion or ALP searches.

    hep-phhep-exhep-thJHEP(2022)·29 citations
14. 14*

    Composite Weak Bosons and a New Isosinglet Particle

    Harald Fritzsch🇩🇪

    The leptons, quarks and weak bosons are bound states of new constituents. An isosinglet weak boson should exist, the X particle, which might have a mass of about 400 GeV and a width of about 20 GeV.

    hep-ph0 citations
15. 15*

    Searching for New Physics with $B_s^0\to D_s^{\pm }{K}^{\mp }$ Decays

    Robert Fleischer🇳🇱 · Eleftheria Malami🇳🇱

    Particularly interesting processes to test the Standard Model are non-leptonic $B_s^0\to D_s^{\pm }{K}^{\mp }$ transitions. As these decays occur via pure tree diagrams, they allow a theoretically clean determination of the angle $\gamma$ of the unitarity triangle. Considering recent LHCb results, an intriguing picture arises, showing tension with the Standard Model. Utilising the available experimental data, we perform a theoretical analysis in order to shed more light on these puzzling patterns. Do these puzzles actually indicate footprints of New Physics?

    hep-phhep-exPoS(2022)·2 citations
16. 16*

    Description of interference in hadron and parton showers by Laplace method

    O.S. Potiienko🇺🇦 · I.V. Sharph🇺🇦 · N.O. Chudak🇺🇦 · D.S. Domin🇺🇦 · I.O. Shelkovenko🇺🇦 · K.K. Merkotan🇺🇦

    We apply Laplace method for the tree diagrams to calculate the interference terms arising as a result of summation of particles permutations in the final state of scattering. These terms significantly influence the values of experimentally observed quantities. We show that the tree diagram with a single input line and an arbitrary number of output lines has a maximum value for the equal four-momenta of secondary particles. It means the tree diagrams of inelastic scattering describe the formation of parton and hadron showers. We also demonstrate the need to take into account the contributions from interference between different showers.

    hep-ph0 citations
17. 17*

    Jet tomography in hot QCD medium with deep learning

    Yi-Lun Du🇳🇴 · Daniel Pablos🇮🇹 · Konrad Tywoniuk🇳🇴

    With deep learning techniques, the degree of modification of energetic jets that traversed hot QCD medium can be identified on a jet-by-jet basis. Due to the strong correlations between the degree of jet modification and its traversed length in the medium, we demonstrate the power of our novel method to locate the creation point of a dijet pair in the nuclear overlap region. In particular, jet properties, such as jet width and orientation can serve as additional handles to locate the creation points to a higher level of precision, which constitutes a significant development towards the long-standing goal of using jets as tomographic probes of the quark-gluon plasma.

    hep-phPoS(2022)·5 citations
18. 18*

    Classification of quark and gluon jets in hot QCD medium with deep learning

    Yi-Lun Du🇳🇴 · Daniel Pablos🇮🇹 · Konrad Tywoniuk🇳🇴

    Deep learning techniques have shown the capability to identify the degree of energy loss of high-energy jets traversing hot QCD medium on a jet-by-jet basis. The average amount of quenching of quark and gluon jets in hot QCD medium actually have different characteristics, such as their dependence on the in-medium traversed length and the early-developed jet substructures in the evolution. These observations motivate us to consider these two types of jets separately and classify them from jet images with deep learning techniques. We find that the classification performance gradually decreases with increasing degree of jet modification. In addition, we discuss the predictive power of different jet observables, such as the jet shape, jet fragmentation function, jet substructures as well as their combinations, in order to address the interpretability of the classification task.

    hep-phnucl-thPoS(2022)·8 citations
19. 19*

    Constraints on GeV Dark Matter interaction with baryons, from a novel Dewar experiment

    Xingchen Xu🇺🇸 · Glennys R. Farrar🇺🇸

    Dark matter which scatters off ordinary matter with a relatively large cross section cannot be constrained by deep underground WIMP experiments, due to the energy loss of DM along its path. However, for a sufficiently large cross section, DM particles in the GeV mass range can be captured and thermalized within Earth, resulting in the accumulation of a DM atmosphere whose number density can be as large as $10^{14}{\text{ cm}}^{-3}$ at Earth's surface. (If the DM-nucleon interaction is attractive and bound states can be formed, most DM bind to nuclei and the density is much lower.) Neufeld and Brach-Neufeld performed experiments to constrain the DM-baryon scattering cross section of DM atmosphere around Earth, by measuring the evaporation rate of liquid nitrogen in a storage dewar within which various materials are immersed. If the DM-nitrogen cross section is in an appropriate range, room temperature DM would penetrate the dewar walls and scatter on the cold nitrogen, increasing its evaporation rate beyond the observed level. Limits on the cross section of DM with other materials than nitrogen are obtained by adding known amounts of different materials; if the material is heated by interactions with DM, that heats and evaporates the liquid nitrogen. Because Born approximation is in general invalid in much of the relevant cross section regime, it is non-trivial to interpret such experimental results as a limit on the DM-nucleon cross section. In this paper we derive the constraints on DM-baryon scattering, with the interaction modeled as a Yukawa potential sourced by the finite sized nucleus. Combining the dewar constraints with BBN, we exclude for the first time a cross section above $10^{-26}{\text{ cm}}^2$ for DM mass 0.8-5.5 GeV, for any sign interaction. One DM model that is constrained is sexaquark $(uuddss)$ DM with mass $m_X\sim 2$ GeV; it remains viable.

    hep-phastro-ph.CO22 citations
20. 20*

    Sterile neutrino dark matter production in presence of non-standard neutrino self-interactions: an EFT approach

    Cristina Benso🇩🇪 · Werner Rodejohann🇩🇪 · Manibrata Sen🇩🇪 · Aaroodd Ujjayini Ramachandran🇩🇪

    Sterile neutrinos with keV-scale masses are popular candidates for warm dark matter. In the most straightforward case they are produced via oscillations with active neutrinos. We introduce effective self-interactions of active neutrinos and investigate the effect on the parameter space of sterile neutrino mass and mixing. Our focus is on mixing with electron neutrinos, which is subject to constraints from several upcoming or running experiments like TRISTAN, ECHo, BeEST and HUNTER. Depending on the size of the self-interaction, the parameter space moves closer to, or further away from, the one testable by those future experiments. In particular, we show that phase 3 of the HUNTER experiment would test a larger amount of parameter space in the presence of self-interactions than without them. We also investigate the effect of the self-interactions on the free-streaming length of the sterile neutrino dark matter, which is important for structure formation observables.

    hep-phastro-ph.COhep-exPRD(2022)·25 citations
21. 21*

    Hot New Early Dark Energy: Towards a Unified Dark Sector of Neutrinos, Dark Energy and Dark Matter

    Florian Niedermann🇸🇪 · Martin S. Sloth🇩🇰

    Hot new early dark energy describes a supercooled, first-order phase transition that takes place at sub-eV temperatures in the dark sector. It lowers the sound horizon, which provides a possible solution to the Hubble tension, and, at the same time, it can explain the neutrino masses through the inverse seesaw mechanism by making a set of sterile Majorana fermions massive. First, we argue that this scenario strengthens existing cosmological bounds on the heaviest neutrino mass. This, in turn, constrains the dark sector temperature, which provides us in total with two falsifiable predictions. In a second step, we discuss the phenomenological consequences of embedding hot new early dark energy in a larger gauge group that is partially broken above the TeV scale. This novel theory, which could even be motivated independently of the Hubble tension, completes the high-energy corner of the inverse seesaw mechanism and explains the mass of a dark matter candidate that can be produced through gravitational interactions at high energies.

    hep-phastro-ph.COhep-thPLB(2022)·56 citations
22. 22*

    Detectable Gravitational Wave Signals from Inflationary Preheating

    Yanou Cui🇺🇸 · Evangelos I. Sfakianakis🇪🇸

    We consider gravitational wave (GW) production during preheating in hybrid inflation models where an axion-like waterfall field couples to Abelian gauge fields. Based on a linear analysis, we find that the GW signal from such models can be within the reach of a variety of foreseeable GW experiments such as LISA, AEDGE, ET and CE, and is close to that of LIGO A+, both in terms of frequency range and signal strength. Furthermore, the resultant GW signal is helically polarized and thus may distinguish itself from other sources of stochastic GW background. Finally, such models can produce primordial black holes that can compose dark matter and lead to merger events detectable by GW detectors.

    hep-phastro-ph.COgr-qchep-thPLB(2023)·22 citations
23. 23*

    Light sterile neutrinos and lepton-number-violating kaon decays in effective field theory

    Guanghui Zhou🇳🇱

    We investigate lepton-number-violating decays $K^{\mp }\to {\pi }^{\pm }{l}^{\mp }{l}^{\mp }$ in the presence of sterile neutrinos. We consider minimal interactions with Standard-Model fields through Yukawa couplings as well as higher-dimensional operators in the framework of the neutrino-extended Standard Model Effective Field Theory. We use $SU(3)$ chiral perturbation theory to match to mesonic interactions and compute the lepton-number-violating decay rate in terms of the neutrino masses and the Wilson coefficients of higher-dimensional operators. For neutrinos that can be produced on-shell, the decay rates are highly enhanced and higher-dimensional interactions can be probed up to very high scales around $\mathcal{O}$(30) TeV.

    hep-phJHEP(2022)·14 citations
24. 24*

    Constraining new physics with SModelS version 2

    Gaël Alguero🇫🇷 · Jan Heisig🇧🇪 · Charanjit Khosa🇮🇹 · Sabine Kraml🇫🇷 · Suchita Kulkarni🇦🇹 · Andre Lessa🇧🇷 · Humberto Reyes-González🇮🇹 · Wolfgang Waltenberger🇦🇹 · Alicia Wongel🇩🇪

    We present version 2 of SModelS, a program package for the fast reinterpretation of LHC searches for new physics on the basis of simplified model results. The major novelty of the SModelS v2 series is an extended topology description with a flexible number of particle attributes, such as spin, charge, decay width, etc. This enables, in particular, the treatment of a wide range of signatures with long-lived particles. Moreover, constraints from prompt and long-lived searches can be evaluated simultaneously in the same run. The current database includes results from searches for heavy stable charged particles, disappearing tracks, displaced jets and displaced leptons, in addition to a large number of prompt searches. The capabilities of the program are demonstrated by two physics applications: constraints on long-lived charged scalars in the scotogenic model, and constraints on the electroweak-ino sector in the Minimal Supersymmetric Standard Model.

    hep-phhep-exJHEP(2022)·98 citations
25. 25*

    Hot New Early Dark Energy

    Florian Niedermann🇸🇪 · Martin S. Sloth🇩🇰

    New early dark energy (NEDE) makes the cosmic microwave background consistent with a higher value of the Hubble constant inferred from supernovae observations. It is an improvement over the old early dark energy model (EDE) because it explains naturally the decay of the extra energy component in terms of a vacuum first-order phase transition that is triggered by a subdominant scalar field at zero temperature. With hot NEDE, we introduce a new mechanism to trigger the phase transition. It relies on thermal corrections that subside as a subdominant radiation fluid in a dark gauge sector cools. We explore the phenomenology of hot NEDE and identify the strong supercooled regime as the scenario favored by phenomenology. In a second step, we propose different microscopic embeddings of hot NEDE. This includes the (non-)Abelian dark matter model, which has the potential to also resolve the LSS tension through interactions with the dark radiation fluid. We also address the coincidence problem generically present in EDE models by relating NEDE to the mass generation of neutrinos via the inverse seesaw mechanism. We finally propose a more complete dark sector model, which embeds the NEDE field in a larger symmetry group and discuss the possibility that the hot NEDE field is central for spontaneously breaking lepton number symmetry.

    hep-phastro-ph.COhep-thPRD(2022)·85 citations
26. 26*

    Phase structure of 2+1-flavour QCD and the magnetic equation of state

    Fei Gao🇩🇪 · Jan M. Pawlowski🇩🇪

    We determine the chiral phase structure of $2+1$-flavour QCD in dependence of temperature and the light flavour quark mass with Dyson-Schwinger equations. Specifically, we compute the renormalised chiral condensate and its susceptibility. The latter is used to determine the (pseudo)critical temperature for general light current quark masses. In the chiral limit we obtain a critical temperature of about 141\,MeV. This result is in quantitative agreement with recent functional renormalisation group results in QCD, and is compatible with the respective lattice results. We also compute the order parameter potential of the light chiral condensate and map out the regime in the phase diagram which exhibits quasi-massless modes, and discuss the respective chiral dynamics.

    hep-phhep-lathep-thnucl-thPRD(2022)·29 citations
27. 27*

    Pseudoscalar sterile neutrino self-interactions in light of Planck, SPT and ACT data

    Mattia Atzori Corona🇮🇹 · Riccardo Murgia🇫🇷 · Matteo Cadeddu🇮🇹 · Maria Archidiacono🇮🇹 · Stefano Gariazzo🇮🇹 · Carlo Giunti🇮🇹 · Steen Hannestad🇩🇰

    We reassess the viability of a cosmological model including a fourth additional sterile neutrino species that self-interacts through a new pseudoscalar degree of freedom. We perform a series of extensive analyses fitting various combinations of cosmic microwave background (CMB) data from Planck, the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT), both alone and in combination with Baryon Acoustic Oscillation (BAO) and Supernova Ia (SnIa) observations. We show that the scenario under study, although capable to resolve the Hubble tension without worsening the so-called $S_8$ tension about the growth of cosmic structures, is severely constrained by high-multipole polarization data from both Planck and SPT. Intriguingly, when trading Planck TE-EE data for those from ACT, we find a $\gtrsim 3\sigma$ preference for a non-zero sterile neutrino mass, $m_s=3.6_{-0.6}^{+1.1}$ eV (68 % C.L.), compatible with the range suggested by longstanding short-baseline (SBL) anomalies in neutrino oscillation experiments. The pseudoscalar model provides indeed a better fit to ACT data compared to $\Lambda$CDM ($\Delta {\chi }^2\simeq -5$, $\Delta \mathrm{AIC}=-1.3$), although in a combined analysis with Planck the $\Lambda$CDM model is still favoured, as the preference for a non-zero sterile neutrino mass is mostly driven by ACT favouring a higher value for the primordial spectral index $n_s$ with respect to Planck. We show that the mild tension between Planck and ACT is due to the different pattern in the TE and EE power spectra on multipoles between $350\lesssim \ell \lesssim 1000$. We also check the impact of marginalizing over the gravitational lensing information in Planck data, showing that the model does not solve the CMB lensing anomaly. Future work including higher precision data from current and upcoming CMB ground-based experiments will be crucial to test these results.

    ↳ astro-ph.COhep-phJCAP(2022)·27 citations
28. 28*

    Noether's theorems and the energy-momentum tensor in quantum gauge theories

    Adam Freese🇺🇸

    Noether's first and second theorems both imply conserved currents that can be identified as an energy-momentum tensor (EMT). The first theorem identifies the EMT as the conserved current associated with global spacetime translations, while the second theorem identifies it as a conserved current associated with local spacetime translations. This work obtains an EMT for quantum electrodynamics and quantum chromodynamics through the second theorem, which is automatically symmetric in its indices and invariant under the expected symmetries (e.g., BRST invariance) without the need for introducing an ad hoc improvement procedure.

    ↳ hep-thhep-phnucl-thPRD(2022)·38 citations
29. 29*

    Do reverberation-measured H$\beta$ quasars provide a useful test of cosmology?

    Narayan Khadka🇺🇸 · Mary Loli Martínez-Aldama🇵🇱 · Michal Zajaček🇨🇿 · Bożena Czerny🇵🇱 · Bharat Ratra🇺🇸

    We use 118 H$\beta$ quasar (QSO) observations in the redshift range $0.0023\le z\le 0.89$ to simultaneously constrain cosmological model parameters and QSO 2-parameter radius-luminosity ($R-L$) relation parameters in six different cosmological models. We find that the $R-L$ relation parameters for these QSOs are independent of the assumed cosmology so these QSOs seem to be standardizable through the $R-L$ relation (although there is a complication that might render this untrue). Cosmological constraints obtained using these QSOs are weak, more favor currently decelerated cosmological expansion, and typically are in $\sim 2\sigma$ tension with those obtained from a joint analysis of baryon acoustic oscillation and Hubble parameter measurements. Extending the $R-L$ relation to a 3-parameter one to try to correct for the accretion rate effect does not result in a reduction of the cosmological constraints discrepancy nor does it result in the hoped-for significant reduction of the intrinsic scatter of the $R-L$ relation.

    ↳ astro-ph.COgr-qchep-phhep-thMNRAS(2022)·34 citations
30. 30*

    Physics with CEBAF at 12 GeV and Future Opportunities

    J. Arrington🇺🇸 · M. Battaglieri🇺🇸 · A. Boehnlein🇺🇸 · S.A. Bogacz🇺🇸 · W.K. Brooks🇨🇱 · E. Chudakov🇺🇸 · I. Cloet🇺🇸 · R. Ent🇺🇸 · H. Gao🇺🇸 · J. Grames🇺🇸 · L. Harwood🇺🇸 · X.Ji🇺🇸 and 12 other authors

    We summarize the ongoing scientific program of the 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF) and give an outlook into future scientific opportunities. The program addresses important topics in nuclear, hadronic, and electroweak physics including nuclear femtography, meson and baryon spectroscopy, quarks and gluons in nuclei, precision tests of the standard model, and dark sector searches. Potential upgrades of CEBAF are considered, such as higher luminosity, polarized and unpolarized positron beams, and doubling the beam energy.

    ↳ nucl-exhep-exhep-phnucl-thPPNP(2022)·133 citations
31. 31*

    Equation of state of QCD at finite chemical potential from an alternative expansion scheme

    Paolo Parotto🇩🇪 · Szabolcs Borsanyi🇩🇪 · Zoltan Fodor🇩🇪 · Jana N. Guenther🇩🇪 · Ruben Kara🇩🇪 · Sandor D. Katz🇭🇺 · Attila Pasztor🇭🇺 · Claudia Ratti🇺🇸 · Kalman K. Szabo🇩🇪

    The equation of state of Quantum Chromodynamics (QCD) at finite density is currently known only in a limited range in the baryon chemical potential ${\mu }_B$. This is due to fundamental shortcomings of traditional methods such as Taylor expansion around ${\mu }_B=0$. In this contribution, we present an alternative scheme that displays substantially improved convergence over the Taylor expansion method. We calculate the alternative expansion coefficients in the continuum, and show our results for the thermodynamic observables up to ${\mu }_B/T\le 3.5$.

    ↳ hep-lathep-phnucl-thPoS(2022)·1 citation
32. 32*

    Recent progress on nucleon form factors

    Dalibor Djukanovic🇩🇪

    The form factors of the nucleon provide key information on nucleon properties. When confronted with precisely measured observables from experiments, they serve as benchmark quantities for lattice calculations. On the other hand lattice determinations may serve as vital theory input for the interpretation of experiments, e.g. in neutrino-nucleus scattering. I review recent progress in the calculation of nucleon form factors on the lattice and its relevance to future experiments.

    ↳ hep-lathep-phnucl-thPoS(2022)·11 citations
33. 33*

    Flavor number dependence of QCD at finite density by the complex Langevin method

    Yusuke Namekawa🇯🇵 · Yuhma Asano🇯🇵 · Yuta Ito🇯🇵 · Takashi Kaneko🇯🇵 · Hideo Matsufuru🇯🇵 · Jun Nishimura🇯🇵 · Asato Tsuchiya🇯🇵 · Shoichiro Tsutsui🇯🇵 · Takeru Yokota🇯🇵

    We discuss the flavor number dependence of QCD at low temperature and high density by the complex Langevin method. In our previous work, the complex Langevin method is confirmed to satisfy the criterion for correct convergence in certain regions, such as ${\mu }_{\mathrm{q}}/T=5.2-7.2$ on $8^3\times 16$ and ${\mu }_{\mathrm{q}}/T=1.6-9.6$ on $16^3\times 32$ using $N_{\mathrm{f}}=4$ staggered fermion at $\beta =5.7$. We extend this study to more realistic flavor cases, $N_{\mathrm{f}}=2,2+1,3$, using Wilson fermions. We present the flavor number dependence of the validity regions of the complex Langevin method and the quark number.

    ↳ hep-lathep-phPoS(2022)·7 citations
34. 34*

    Approximate Bayesian Computation Applied to the Diffuse Gamma-ray Sky

    Eric J. Baxter🇺🇸 · J. G. Christy🇺🇸 · Jason Kumar🇺🇸

    Many sources contribute to the diffuse gamma-ray background (DGRB), including star forming galaxies, active galactic nuclei, and cosmic ray interactions in the Milky Way. Exotic sources, such as dark matter annihilation, may also make some contribution. The photon counts-in-pixels distribution is a powerful tool for analyzing the DGRB and determining the relative contributions of different sources. However, including photon energy information in a likelihood analysis of the counts-in-pixels distribution quickly becomes computationally intractable as the number of source types and energy bins increase. Here, we apply the likelihood-free method of Approximate Bayesian Computation (ABC) to the problem. We consider a mock analysis that includes contributions from dark matter annihilation in galactic subhalos as well as astrophysical backgrounds. We show that our results using ABC are consistent with the exact likelihood when energy information is discarded, and that significantly tighter parameter constraints can be obtained with ABC when energy information is included. ABC presents a powerful tool for analyzing the DGRB and understanding its varied origins.

    ↳ astro-ph.HEastro-ph.COastro-ph.IMhep-phMNRAS(2022)·7 citations
35. 35*

    Lifetimes of light stringy states

    Pascal Anastasopoulos (Vienna U.)🇦🇹 · Elias Niederwieser (Vienna U.)🇦🇹

    In this paper, we evaluate the lifetime of the light stringy states that emerge in intersecting D-brane realisations of the Standard Model. For concreteness, we focus on a light massive scalar decaying into two massless fermions. Given the present experimental lower bounds of the string scale, we extrapolate the lifetime as a function of the intersection angles to very small angles in order to have states with lifetimes of the order of the universe. That provides an alluring example of a massive, very weakly interacting field with a huge lifetime, proposing itself as a potential dark matter candidate.

    ↳ hep-thhep-phNPB(2022)·2 citations
36. 36*

    Deep inelastic scattering off quark-gluon plasma and its photon emissivity

    Marco Cè🇨🇭 · Tim Harris🇬🇧 · Harvey B. Meyer🇩🇪 · Arianna Toniato🇩🇪 · Csaba Török🇩🇪

    The photon emissivity of quark-gluon plasma probes the interactions in the medium and differs qualitatively between a weakly coupled and a strongly coupled plasma in the soft-photon regime. The photon emissivity is given by the product of kinematic factors and a spectral function associated with the two-point correlator of the electromagnetic current at lightlike kinematics. A certain Euclidean correlator at imaginary spatial momentum can be calculated in lattice QCD and is given by an integral over the relevant spectral function at lightlike kinematics. I present a first exploratory lattice calculation of this correlator. Secondly, I show how Euclidean correlators at imaginary spatial momenta can also be used to probe the regime of deep inelastic scattering off quark-gluon plasma, which reveals its parton distribution function.

    ↳ hep-lathep-phPoS(2022)·8 citations
37. 37*

    Machine learning Hadron Spectral Functions in Lattice QCD

    Shi-Yang Chen🇨🇳 · Heng-Tong Ding🇨🇳 · Fei-Yi Liu🇨🇳 · Gabor Papp🇭🇺 · Chun-Bin Yang🇨🇳

    Hadron spectral functions carry all the information of hadrons and are encoded in the Euclidean two-point correlation functions. The extraction of hadron spectral functions from the correlator is a typical ill-posed inverse problem and infinite number of solutions to this problem exists. We propose a novel neural network (sVAE) based on the Variation Auto-Encoder (VAE) and Bayesian theorem. Inspired by the maximum entropy method (MEM) we construct the loss function of the neural work such that it includes a Shannon-Jaynes entropy term and a likelihood term. The sVAE is then trained to provide the most probable spectral functions. For the training samples of spectral function we used general spectral functions produced from the Gaussian Mixture Model. After the training is done we performed the mock data tests with input spectral functions consisting 1) only a free continuum, 2) only a resonance peak, 3) a resonance peak plus a free continuum and 4) a NRQCD motivated spectral function. From the mock data test we find that the sVAE in most cases is comparable to the maximum entropy method in the quality of reconstructing spectral functions and even outperforms the MEM in the case where the spectral function has sharp peaks with insufficient number of data points in the correlator. By applying to temporal correlation functions of charmonium in the pseudoscalar channel obtained in the quenched lattice QCD at 0.75 $T_c$ on $128^3\times 96$ lattices and $1.5$ $T_c$ on $128^3\times 48$ lattices, we find that the resonance peak of ${\eta }_c$ extracted from both the sVAE and MEM has a substantial dependence on the number of points in the temporal direction ($N_{\tau }$) adopted in the lattice simulation and $N_{\tau }$ larger than 48 is needed to resolve the fate of ${\eta }_c$ at 1.5 $T_c$.

    ↳ hep-latcs.LGhep-phhep-th+1PoS(2022)·4 citations
38. 38*

    Correlated Dirac Eigenvalues and Axial Anomaly in Chiral Symmetric QCD

    Heng-Tong Ding🇨🇳 · Sheng-Tai Li🇨🇳 · Swagato Mukherjee🇺🇸 · Akio Tomiya🇺🇸 · Xiao-Dan Wang🇨🇳 · Yu Zhang🇯🇵

    We investigate the Dirac eigenvalue spectrum ($\rho (\lambda ,m_l)$) to study the microscopic origin of axial anomaly in high temperature phase of QCD. We propose novel relations between the derivatives (${\partial }^n\rho (\lambda ,m_l)/\partial m_l^n$) of the Dirac eigenvalue spectrum with respect to the quark mass ($m_l$) and the $(n+1)$-point correlations among the eigenvalues ($\lambda$) of the massless Dirac operator. Based on these relations, we present lattice QCD results for ${\partial }^n\rho (\lambda ,m_l)/\partial m_l^n$ ($n=1,2,3$) with $m_l$ corresponding to pion masses $m_{\pi }=160-55$ MeV, and at a temperature of about 1.6 times the chiral phase transition temperature. Calculations were carried out using (2+1)-flavors of highly improved staggered quarks and the tree-level Symanzik gauge action with the physical strange quark mass, three lattice spacings $a=0.12,0.08,0.06$ fm, and lattices having aspect ratios $4-9$. We find that $\rho (\lambda \to 0,m_l)$ develops a peaked structure. This peaked structure, which arises due to non-Poisson correlations within the infrared part of the Dirac eigenvalue spectrum, becomes sharper as $a\to 0$, and its amplitude is proportional to $m_l^2$. After continuum and chiral extrapolations, we find that the axial anomaly remains manifested in two-point correlation functions of scalar and pseudo-scalar mesons in the chiral limit. We demonstrate that the behavior of $\rho (\lambda \to 0,m_l)$ is responsible for it.

    ↳ hep-lathep-phhep-thnucl-thPoS(2022)·4 citations
39. 39*

    How Special Are Black Holes? Correspondence with saturons in generic theories

    Gia Dvali🇩🇪 · Oleg Kaikov🇩🇪 · Juan Sebastián Valbuena Bermúdez🇩🇪

    Black holes are considered to be exceptional due to their time evolution and information processing. However, it was proposed recently that these properties are generic for objects, the so-called saturons, that attain the maximal entropy permitted by unitarity. In the present paper, we verify this connection within a renormalizable $SU(N)$ invariant theory. We show that the spectrum of the theory contains a tower of bubbles representing bound states of $SU(N)$ Goldstones. Despite the absence of gravity, a saturated bound state exhibits a striking correspondence with a black hole: Its entropy is given by the Bekenstein-Hawking formula; semi-classically, the bubble evaporates at a thermal rate with a temperature equal to its inverse radius; the information retrieval time is equal to Page's time. The correspondence goes through a trans-theoretic entity of Poincaré Goldstone. The black hole/saturon correspondence has important implications for black hole physics, both fundamental and observational.

    ↳ hep-thgr-qchep-phPRD(2022)·37 citations
40. 40*

    Excited Q-Balls

    Yahya Almumin🇺🇸 · Julian Heeck🇺🇸 · Arvind Rajaraman🇺🇸 · Christopher B. Verhaaren🇺🇸

    Complex scalars in U(1)-symmetric potentials can form stable Q-balls, non-topological solitons that correspond to spherical bound-state solutions. If the U(1) charge of the Q-ball is large enough, it can support a tower of unstable radial excitations with increasing energy. Previous analyses of these radial excitations were confined to fixed parameters, leading to excited states with different charges $Q$. In this work, we provide the first characterization of the radial excitations of solitons for fixed charge, providing the physical spectrum for such objects. We also show how to approximately describe these excited states analytically and predict their global properties such as radius, energy, and charge. This enables a complete characterization of the radial spectrum. We also comment on the decay channels of these excited states.

    ↳ hep-thhep-phEPJC(2022)·24 citations
41. 41*

    On Holography in General Background and the Boundary Effective Action from AdS to dS

    Sylvain Fichet🇧🇷

    We study quantum fields on an arbitrary, rigid background with boundary. We derive the action for a scalar in the holographic basis that separates the boundary and bulk degrees of freedom. A relation between Dirichlet and Neumann propagators valid for any background is obtained from this holographic action. As a simple application, we derive an exact formula for the flux of bulk modes emitted from the boundary in a warped background. We also derive a formula for the Casimir pressure on a $(d-1)$-brane depending only on the boundary-to-bulk propagators, and apply it in AdS. Turning on couplings and using the holographic basis, we evaluate the one-loop boundary effective action in AdS by means of the heat kernel expansion. We extract anomalous dimensions of single and double trace CFT operators generated by loops of heavy scalars and nonabelian vectors, up to third order in the large squared mass expansion. From the boundary heat kernel coefficients we identify CFT operator mixing and corrections to OPE data, in addition to the radiative generation of local operators. We integrate out nonabelian vector fluctuations in AdS${}_{4,5,6}$ and obtain the associated holographic Yang-Mills $\beta$ functions. Turning to the expanding patch of dS, following recent proposals, we provide a boundary effective action generating the perturbative cosmological correlators using analytical continuation from dS to EAdS. We obtain the "cosmological" heat kernel coefficients in the scalar case and work out the divergent part of the dS${}_4$ effective action which renormalizes the cosmological correlators. We find that bulk masses and wavefunction can logarithmically run as a result of the dS${}_4$ curvature, and that operators on the late time boundary are radiatively generated. More developments are needed to extract all one-loop information from the cosmological effective action.

    ↳ hep-thhep-phJHEP(2022)·33 citations
42. 42*

    Substructure Detection Reanalyzed: Dark Perturber shown to be a Line-of-Sight Halo

    Atınç Çağan Şengül🇺🇸 · Cora Dvorkin🇺🇸 · Bryan Ostdiek🇺🇸 · Arthur Tsang🇺🇸

    Observations of structure at sub-galactic scales are crucial for probing the properties of dark matter, which is the dominant source of gravity in the universe. It will become increasingly important for future surveys to distinguish between line-of-sight halos and subhalos to avoid wrong inferences on the nature of dark matter. We reanalyze a sub-galactic structure (in lens JVAS B1938+666) that has been previously found using the gravitational imaging technique in galaxy-galaxy lensing systems. This structure has been assumed to be a satellite in the halo of the main lens galaxy. We fit the redshift of the perturber of the system as a free parameter, using the multi-plane thin-lens approximation, and find that the redshift of the perturber is $z_{\mathrm{int}}=1.42\begin{array}{c}+0.10\\ -0.15\end{array}$ (with a main lens redshift of $z=0.881$). Our analysis indicates that this structure is more massive than the previous result by an order of magnitude. This constitutes the first dark perturber shown to be a line-of-sight halo with a gravitational lensing method.

    ↳ astro-ph.COastro-ph.GAhep-phMNRAS(2022)·61 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.