Wed·Jun 9, 2021Wednesday·June 9, 2021

1. 01*

   Investigating New Physics Models with Signature of Same-Sign Diboson + ${E/}_T$

   Cheng-Wei Chiang🇹🇼 · Sudip Jana🇩🇪 · Dibyashree Sengupta🇹🇼

   We investigate the prospect of searching for new physics via the novel signature of same-sign diboson + ${E/}_T$ at current and future LHC. We study three new physics models: (i) natural SUSY models, (ii) type-III seesaw model and (iii) type-II seesaw/Georgi-Machacek model. In the first two class of models, this signature arises due to the presence of a singly-charged particle which has lifetime long enough to escape detection, while in the third model this signature originates resonantly from a doubly-charged particle produced along with two forward jets that, most likely, would escape detection. We analyze in great detail the discovery prospects of the signal in these three classes of models in the current as well as the upcoming runs of the LHC (such as HL-LHC, HE-LHC and FCC-hh) by showing a distinction among these scenarios.

   hep-phhep-exPRD(2022)·7 citations
2. 02*

   Orbital Angular Momentum Distribution of Gluons at Small-$x$ : Analytic interpolation between Ji and Jaffe-Manohar

   Raktim Abir🇮🇳 · Khatiza Banu🇮🇳 · Nahid Vasim🇮🇳

   In this work, we first introduced a generalized Wilson line gauge link that reproduces both staple and near straight links along the light cone in different parameter limits. We then studied the gauge-invariant bi-local orbital angular momentum operator with such a general gauge link, in the framework of Chen et. al. decomposition of gauge fields. At the appropriate combination of limits, the operator reproduces both Jaffe-Manohar and Ji's operator structure and offers a continuous analytical interpolation between the two.

   hep-phhep-latnucl-thPRD(2022)·8 citations
3. 03*

   Dark Sound

   Alexander Balatsky🇸🇪 · Benjo Fraser🇸🇪 · Henrik Roising🇸🇪

   We discuss the axion dark matter (DM) condensate and the consequences the interactions of dark matter would have on the spectrum of collective modes. We find that DM self-interactions change the spectrum of excitations from a quadratic to a linear-like dispersion with velocity $v_s$ which is set by the interactions, but dominated by gravity. For typical DM densities and interactions we find $v_s\sim 10^{-12}c$. This sound-like mode corresponds to DM density oscillations just like in any other Bose liquid, hence we call it {\em Dark Sound} (DS). The DS mode is well defined and describes stable density oscillations at intermediate length scales $k\ge k_{\text{min}}\sim 10^4\mathrm{ly}{\mathrm{r}}^{-1}$. In the extreme long wavelength limit gravity dominates and leads to Jeans instability of the sound mode at the scale of clump formation $k\le k_{\text{min}}$. We also discuss the possible observable consequences of the DS, including quantized DS modes inside clumps, their characteristic energy, and noise features that might facilitate the observation of DM.

   hep-phgr-qcPRD(2022)·6 citations
4. 04*

   Polynomial Inflation and Dark Matter

   Nicolás Bernal🇨🇴 · Yong Xu🇩🇪

   We present a minimal UV complete framework to embed inflation and dark matter by extending the standard model with a singlet real scalar field (the inflaton) and a singlet fermonic field acting as dark matter. The inflaton features the most general renormalizable polynomial up to quartic order, which is flat due to the existence of a perturbed inflection-point, comfortably fitting CMB measurements. We also analyze (p)reheating by considering the Higgs production via inflaton decay. In the early universe, dark matter can be generated by the mediation of gravitons or inflatons. However, the production via the direct decay of the inflatons dominates, making viable a large range of dark matter masses, from $\mathcal{O}(10^{-5})$ GeV to $\mathcal{O}(10^{11})$ GeV.

   hep-phEPJC(2021)·37 citations
5. 05*

   Neutrino Mass Eigenvalues for Different Scheme within Four Flavor Neutrino framework

   Vivek Kumar Nautiyal🇮🇳 · Bipin Singh Koranga🇮🇳 · Jaydip Singh🇮🇳

   In this paper, we discuss neutrino mass eigenvalues for four flavor neutrino mixing. An extra mass states, in four flavor mixing and possible various combination of CP violating Majorana phases effects the neutrino mass eigenvalues. We have considered the effective Majorana mass m_{e}, related for \,\left(\beta\beta\right)_{0\nu\,} decay. In calculation, we consider two different neutrino mass orders, normal and inverted. We find the limits for neutrino mass eigenvalue m_{i} in the different neutrino mass spectrum and the sum of all four neutrino masses is \text{{\Sigma}}\text{\ensuremath{\equiv}}m_{1}+m_{2}+m_{3}+m_{4}>1.3\,eV\, which is relevant for cosmological observations and explain the different neutrino oscillations data.

   hep-ph0 citations
6. 06*

   Dark matter and low scale leptogenesis in a flavor symmetric neutrino two Higgs doublet model($\nu$2HDM)

   Lavina Sarma🇮🇳 · Bichitra Bijay Boruah🇮🇳 · Mrinal Kumar Das🇮🇳

   We have studied dark matter (DM) phenomenology, neutrinoless double beta decay (NDBD) and realized low scale leptogenesis in an extension of Standard Model(SM) with three neutral fermions, a scalar doublet and a dark sector incorporating a singlet scalar and a Dirac singlet fermion. A generic model based on $A_4\times Z_4$ flavor symmetry including five flavons is used to explain both normal and inverted hierarchy mass patterns of neutrino and also to accommodate the dark matter mass. In this extension of the $\nu$2HDM, the effective neutrino mass observed in $0\nu \beta \beta$ is well within the experimental limit provided by KamLAND-ZEN. In order to validate DM within this model, we have checked relic abundance and free streaming length of the dark sector component, i.e. a Dirac singlet fermion constraining its mass in keV range. More importantly we have also realised low scale leptogenesis simultaneously within this framework and also the Dirac CP phase gets constrained with the results. Bound from LFV is also incorporated in order to constrain the Yukawa couplings. More importantly, we have analyzed the dependence of various phenomenology with decay parameter for different choice of arbitrary complex angles.

   hep-phEPJC(2022)·4 citations
7. 07*

   Probing Magnetic Moment Operators in $H\gamma$ Production and $H\to {\tau }^{+}{\tau }^{-}\gamma$ Rare Decay

   Qing-Hong Cao🇨🇳 · Hao-Ran Jiang🇨🇳 · Bin Li🇨🇳 · Yandong Liu🇨🇳 · Guojin Zeng🇨🇳

   The magnetic moment ($a_{\gamma }$) and weak magnetic moment ($a_W$) of charged leptons and quarks are sensitive to quantum effects of new physics heavy resonances. In effective field theory $a_{\gamma }$ and $a_W$ are induced by two independent operators, therefore, one has to measure both the $a_{\gamma }$ and $a_W$ to shed lights on new physics. The $a_W$'s of the SM fermions are measured at the LEP. In this work, we analyze the contributions from magnetic and weak magnetic moment operators in the processes of $pp\to H\gamma$ and $gg\to H\to {\tau }^{+}{\tau }^{-}\gamma$ at the High-Luminosity Large Hadron Collider. We demonstrate that the two processes could cover most of the parameter space that cannot be probed at the LEP.

   hep-phhep-exCPC(2021)·8 citations
8. 08*

   Glauber gluons in annihilation amplitudes for heavy meson decays

   Hsiang-nan Li🇹🇼

   We investigate the Glauber divergences in nonfactorizable annihilation amplitudes for two-body hadronic heavy meson decays in the $k_T$ factorization theorem at one-loop level. These divergences can be absorbed into the Glauber factors in the dominant kinematic regions of small parton momenta, which modify the interference between a nonfactorizable annihilation amplitude and other amplitudes by rotating it with a phase. We postulate that only the Glauber effect associated with a pion is significant, due to its special role as a $q\bar{q}$ bound state and as a pseudo Nambu-Goldstone boson simultaneously. It is elaborated that the data of the $D\to \pi \pi$ and $\pi K$ branching ratios have revealed prominent Glauber effects. This work provides a solid theoretical ground for the factorization-assisted topological-amplitude parametrization of two-body hadronic $D$ meson decays.

   hep-phChin.J.Phys.(2021)·3 citations
9. 09*

   From quarks and gluons to color superconductivity at supranuclear densities

   Jens Braun🇩🇪 · Benedikt Schallmo🇩🇪

   We study the emergence of color superconductivity in the theory of the strong interaction at supranuclear densities. To this end, we follow the renormalization group (RG) flow of dense strong-interaction matter with two massless quark flavors from the fundamental quark and gluon degrees of freedom at high energies down to the non-perturbative low-energy regime which is found to be governed by the dynamical formation of diquark states. With the strong coupling at the initial RG scale as the only input parameter, we compute the (chirally symmetric) scalar diquark condensate and analyze its scaling behavior over a wide range of the quark chemical potential. Approximations entering our computations are critically assessed. Since our approach naturally allows us to study the scale dependence of couplings, we also monitor the strength of couplings appearing in low-energy models of dense strong-interaction matter. The observed dependence of these couplings on the quark chemical potential may help to amend model studies in the future. Finally, we estimate the speed of sound of dense QCD matter. Our results indicate that the speed of sound exceeds the value of the noninteracting quark gas at high densities and even increases as the density is decreased, across a wide range, suggesting the existence of a maximum at supranuclear densities.

   hep-phnucl-thPRD(2022)·38 citations
10. 10*

    Study of pair production in inhomogeneous two-color electric fields using the computational quantum field theory

    Z. L. Li🇨🇳 · C. Gong🇨🇳 · Y. J. Li🇨🇳

    We first demonstrate theoretically that the computational quantum field theory is equivalent to the quantum kinetic theory for pair creation in a spatially homogeneous and time-dependent electric field, then verify numerically their equivalence for pair creation in one-dimensional time-dependent electric fields, and finally investigate detailedly the effects of the field frequency, spatial width, pulse duration, and relative phase on dynamically assisted Schwinger pair production in an inhomogeneous two-color electric field. It is found that the enhancement effect of pair creation is very sensitive to the field frequency and generally very obvious for a shorter field width, a longer pulse duration, and a relative phase of maximizing the field strength. These results can provide a significant reference for the optimal control theory of pair creation which aims to maximize the created pair yield within a given scope of field parameters.

    hep-phquant-phPRD(2021)·22 citations
11. 11*

    Mixed modulus and anomaly mediation in light of the muon $g-2$ anomaly

    Kwang Sik Jeong🇰🇷 · Junichiro Kawamura🇰🇷 · Chan Beom Park🇰🇷

    The new measurement of the anomalous magnetic moment of muon at the Fermilab Muon $g-2$ experiment has strengthened the significance of the discrepancy between the standard model prediction and the experimental observation from the BNL measurement. If new physics responsible for the muon $g-2$ anomaly is supersymmetric, one should consider how to obtain light electroweakinos and sleptons in a systematic way. The gauge coupling unification allows a robust prediction of the gaugino masses, indicating that the electroweakinos can be much lighter than the gluino if anomaly-mediated supersymmetry breaking is sizable. As naturally leading to mixed modulus-anomaly mediation, the KKLT scenario is of particular interest and is found capable of explaining the muon $g-2$ anomaly in the parameter region where the lightest ordinary supersymmetric particle is a bino-like neutralino or slepton.

    hep-phJHEP(2021)·18 citations
12. 12*

    Indirect dark matter searches at ultrahigh energy neutrino detectors

    Claire Guépin🇺🇸 · Roberto Aloisio🇮🇹 · Luis A. Anchordoqui🇺🇸 · Austin Cummings🇮🇹 · John F. Krizmanic🇺🇸 · Angela V. Olinto🇺🇸 · Mary Hall Reno🇺🇸 · Tonia M. Venters🇺🇸

    High to ultrahigh energy neutrino detectors can uniquely probe the properties of dark matter $\chi$ by searching for the secondary products produced through annihilation and/or decay processes. We evaluate the sensitivities to dark matter thermally averaged annihilation cross section $⟨\sigma v⟩$ and partial decay width into neutrinos ${\Gamma }_{\chi \to \nu \bar{\nu }}$ (in the mass scale $10^7\le m_{\chi }/\mathrm{GeV}\le 10^{15}$) for next generation observatories like POEMMA and GRAND. We show that in the range $10^7\le m_{\chi }/\mathrm{GeV}\le 10^{11}$, space-based Cherenkov detectors like POEMMA have the advantage of full-sky coverage and rapid slewing, enabling an optimized dark matter observation strategy focusing on the Galactic center. We also show that ground-based radio detectors such as GRAND can achieve high sensitivities and high duty cycles in radio quiet areas. We compare the sensitivities of next generation neutrino experiments with existing constraints from IceCube and updated 90\% C.L. upper limits on $⟨\sigma v⟩$ and ${\Gamma }_{\chi \to \nu \bar{\nu }}$ using results from the Pierre Auger Collaboration and ANITA. We show that in the range $10^7\le m_{\chi }/\mathrm{GeV}\le 10^{11}$ POEMMA and GRAND10k will improve the neutrino sensitivity to particle dark matter by factors of 2 to 10 over existing limits, whereas GRAND200k will improve this sensitivity by two orders of magnitude. In the range $10^{11}\le m_{\chi }/\mathrm{GeV}\le 10^{15}$, POEMMA's fluorescence observation mode will achieve an unprecedented sensitivity to dark matter properties. Finally, we highlight the importance of the uncertainties related to the dark matter distribution in the Galactic halo, using the latest fit and estimates of the Galactic parameters.

    hep-phastro-ph.HEPRD(2021)·43 citations
13. 13*

    Gluino-SUGRA scenarios in light of FNAL muon g-2 anomaly

    Zhuang Li🇨🇳 · Guo-Li Liu🇨🇳 · Fei Wang🇨🇳 · Jin Min Yang🇨🇳 · Yang Zhang🇨🇳

    Gluino-SUGRA ($\tilde{g}$SUGRA), which is an economical extension of the predictive mSUGRA, adopts much heavier gluino mass parameter than other gauginos mass parameters and universal scalar mass parameter at the unification scale. It can elegantly reconcile the experimental results on the Higgs boson mass, the muon $g-2$, the null results in search for supersymmetry at the LHC and the results from B-physics. In this work, we propose several new ways to generate large gaugino hierarchy (i.e. $M_3\gg M_1,M_2$) for $\tilde{g}$SUGRA model building and then discuss in detail the implications of the new muon $g-2$ results with the updated LHC constraints on such $\tilde{g}$SUGRA scenarios. We obtain the following observations: (i) For the most interesting $M_1=M_2$ case at the GUT scale with a viable bino-like dark matter, the $\tilde{g}$SUGRA can explain the muon $g-2$ anomaly at $1\sigma$ level and be consistent with the updated LHC constraints for $6\le M_3/M_1\le 9$ at the GUT scale; (ii) For $M_1:M_2=5:1$ at the GUT scale with wino-like dark matter, the $\tilde{g}$SUGRA model can explain the muon $g-2$ anomaly at $2\sigma$ level and be consistent with the updated LHC constraints for $3\le M_3/M_1\le 3.2$ at the GUT scale; (iii) For $M_1:M_2=3:2$ at the GUT scale with mixed bino-wino dark matter, the $\tilde{g}$SUGRA model can explain the muon $g-2$ anomaly at $1\sigma$ level and be consistent with the updated LHC constraints for $6.9\le M_3/M_1\le 7.5$ at the GUT scale. Although the choice of heavy gluino will always increase the FT involved, some of the $1\sigma /2\sigma$ survived points of $\Delta a_{\mu }^{combine}$ can still allow low EWFT of order several hundreds and be fairly natural. Constraints from (dimension-five operator induced) proton decay are also discussed.

    hep-phJHEP(2021)·43 citations
14. 14*

    Chiral magnetic properties of QCD phase-diagram

    Abdel Nasser Tawfik (Egyptian Ctr. Theor. Phys., Cairo and Goethe U., Frankfurt (main))🇪🇬 · Abdel Magied Diab (MUTI, Cairo)🇪🇬

    The QCD phase diagram is studied, at finite magnetic field. Our calculations are based on the QCD effective model, the SU($3$) Polyakov linear sigma model (PLSM), in which the chiral symmetry is integrated in the hadron phase and in the parton phase, the up-, down- and strange-quark degrees of freedom are incorporated besides the inclusion of Polyakov loop potentials in the pure gauge limit, which are motivated by various underlying QCD symmetries. The Landau quantization and the magnetic catalysis are implemented. The response of the QCD matter to an external magnetic field such as magnetization, magnetic susceptibility and permeability has been estimated. We conclude that the parton phase has higher values of magnetization, magnetic susceptibility, and permeability relative to the hadron phase. Depending on the contributions to the Landau levels, we conclude that the chiral magnetic field enhances the chiral quark condensates and hence the chiral QCD phase diagram, i.e. the hadron-parton phase transition likely takes place, at lower critical temperatures and chemical potentials.

    hep-phEPJA(2021)·20 citations
15. 15*

    Inelastic Dark Matter at the Fermilab Short Baseline Neutrino Program

    Brian Batell🇺🇸 · Joshua Berger🇺🇸 · Luc Darmé🇮🇹 · Claudia Frugiuele🇮🇹

    We study the sensitivity of the Fermilab Short-Baseline Neutrino (SBN) experiments, MicroBooNE, ICARUS, and SBND, to MeV- to GeV-scale inelastic dark matter interacting through a dark photon mediator. These models provide interesting scenarios of light thermal dark matter, which, while challenging to probe with direct and indirect detection experiments, are amenable to accelerator-based searches. We consider production of the dark sector states with both the Fermilab Booster 8 GeV and NuMI 120 GeV proton beams and study the signatures of scattering and decay of the heavy excited dark state in the SBN detectors. These distinct signatures probe complementary regions of parameter space. All three experiments will be able to cover new ground, with an excellent near-term opportunity to search for cosmologically motivated targets explaining the observed dark matter abundance.

    hep-phhep-exPRD(2021)·43 citations
16. 16*

    An analysis of Bayesian estimates for missing higher orders in perturbative calculations

    Claude Duhr🇨🇭 · Alexander Huss🇨🇭 · Aleksas Mazeliauskas🇨🇭 · Robert Szafron🇺🇸

    With current high precision collider data, the reliable estimation of theoretical uncertainties due to missing higher orders (MHOs) in perturbation theory has become a pressing issue for collider phenomenology. Traditionally, the size of the MHOs is estimated through scale variation, a simple but ad hoc method without probabilistic interpretation. Bayesian approaches provide a compelling alternative to estimate the size of the MHOs, but it is not clear how to interpret the perturbative scales, like the factorisation and renormalisation scales, in a Bayesian framework. Recently, it was proposed that the scales can be incorporated as hidden parameters into a Bayesian model. In this paper, we thoroughly scrutinise Bayesian approaches to MHO estimation and systematically study the performance of different models on an extensive set of high-order calculations. We extend the framework in two significant ways. First, we define a new model that allows for asymmetric probability distributions. Second, we introduce a prescription to incorporate information on perturbative scales without interpreting them as hidden model parameters. We clarify how the two scale prescriptions bias the result towards specific scale choice, and we discuss and compare different Bayesian MHO estimates among themselves and to the traditional scale variation approach. Finally, we provide a practical prescription of how existing perturbative results at the standard scale variation points can be converted to 68%/95% credibility intervals in the Bayesian approach using the new public code MiHO.

    hep-phhep-exJHEP(2021)·64 citations
17. 17*

    The soft drop momentum sharing fraction $z_g$ beyond leading-logarithmic accuracy

    Pedro Cal🇳🇱 · Kyle Lee🇺🇸 · Felix Ringer🇺🇸 · Wouter J. Waalewijn🇳🇱

    Grooming techniques, such as soft drop, play a central role in reducing sensitivity of jets to e.g. underlying event and hadronization at current collider experiments. The momentum sharing fraction $z_g$, of the two branches in a jet that pass the soft drop condition, is one of the most important observables characterizing a collinear splitting inside the jet, and directly probes the QCD splitting functions. In this work, we present a factorization framework that enables a systematic calculation of the corresponding cross section beyond leading-logarithmic (LL) accuracy, showing that this measurement is not only sensitive to the QCD charge but also the spin of the parton that initiates the jet. Our results at next-to-leading logarithmic (NLL${}^{\prime }$) accuracy include non-global logarithms, and provide a first meaningful assessment of the perturbative uncertainty. We present a comparison to the available experimental data from ALICE, ATLAS, and STAR and find excellent agreement.

    hep-phhep-exnucl-exnucl-thPLB(2022)·29 citations
18. 18*

    Sliding Naturalness

    Raffaele Tito D'Agnolo🇫🇷 · Daniele Teresi🇨🇭

    We present a novel framework to solve simultaneously the electroweak hierarchy problem and the strong-CP problem. A small but finite Higgs vacuum expectation value and a small $\theta$-angle are selected after the QCD phase transition, without relying on the Peccei-Quinn mechanism or other traditional solutions. We predict a distinctive pattern of correlated signals at hadronic EDM, fuzzy dark matter and axion experiments.

    hep-phastro-ph.COhep-exhep-thPRL(2022)·55 citations
19. 19*

    Impact of Improved Energy Resolution on DUNE sensitivity to Neutrino Non-Standard Interactions

    Sabya Sachi Chatterjee🇬🇧 · P. S. Bhupal Dev🇺🇸 · Pedro A. N. Machado🇺🇸

    The full physics potential of the next-generation Deep Underground Neutrino Experiment (DUNE) is still being explored. In particular, there have been some recent studies on the possibility of improving DUNE's neutrino energy reconstruction. The main motivation is that a better determination of the neutrino energy in an event-by-event basis will translate into an improved measurement of the Dirac $CP$ phase and other neutrino oscillation parameters. To further motivate studies and improvements on the neutrino energy reconstruction, we evaluate the impact of energy resolution at DUNE on an illustrative new physics scenario, viz. non-standard interactions (NSI) of neutrinos with matter. We show that a better energy resolution in comparison to the ones given in the DUNE conceptual and technical design reports may significantly enhance the experimental sensitivity to NSI, particularly when degeneracies are present. While a better reconstruction of the first oscillation peak helps disentangling standard $CP$ effects from those coming from NSIs, we find that the second oscillation peak also plays a nontrivial role in improving DUNE's sensitivity.

    hep-phhep-exJHEP(2021)·41 citations
20. 20*

    SPANet: Generalized Permutationless Set Assignment for Particle Physics using Symmetry Preserving Attention

    Alexander Shmakov🇺🇸 · Michael James Fenton🇺🇸 · Ta-Wei Ho🇹🇼 · Shih-Chieh Hsu🇺🇸 · Daniel Whiteson🇺🇸 · Pierre Baldi🇺🇸

    The creation of unstable heavy particles at the Large Hadron Collider is the most direct way to address some of the deepest open questions in physics. Collisions typically produce variable-size sets of observed particles which have inherent ambiguities complicating the assignment of observed particles to the decay products of the heavy particles. Current strategies for tackling these challenges in the physics community ignore the physical symmetries of the decay products and consider all possible assignment permutations and do not scale to complex configurations. Attention based deep learning methods for sequence modelling have achieved state-of-the-art performance in natural language processing, but they lack built-in mechanisms to deal with the unique symmetries found in physical set-assignment problems. We introduce a novel method for constructing symmetry-preserving attention networks which reflect the problem's natural invariances to efficiently find assignments without evaluating all permutations. This general approach is applicable to arbitrarily complex configurations and significantly outperforms current methods, improving reconstruction efficiency between 19\% - 35\% on typical benchmark problems while decreasing inference time by two to five orders of magnitude on the most complex events, making many important and previously intractable cases tractable. A full code repository containing a general library, the specific configuration used, and a complete dataset release, are avaiable at https://github.com/Alexanders101/SPANet

    ↳ hep-excs.LGhep-phSciPost Phys.(2022)·83 citations
21. 21*

    Robust orbital diamagnetism of correlated Dirac fermions in chiral Ising universality class

    Yasuhiro Tada🇯🇵

    We study orbital diamagnetism at zero temperature in $(2+1)$-dimensional Dirac fermions with a short-range interaction which exhibits a quantum phase transition to a charge density wave (CDW) phase. We introduce orbital magnetic fields into spinless Dirac fermions on the $\pi$-flux square lattice, and analyze them by using infinite density matrix renormalization group. It is found that the diamagnetism remains intact in the Dirac semimetal regime as a result of a non-trivial competition between the enhanced Fermi velocity and magnetic-field-induced mass gap, while it is monotonically suppressed in the CDW regime. Around the quantum critical point (QCP) of the CDW phase transition, we find a scaling behavior of the diamagnetism characteristic of the chiral Ising universality class. This defines a universal behavior of orbital diamagnetism in correlated Dirac fermions around a QCP, and therefore the robust diamagnetism in the semimetal regime is a universal property of Dirac systems whose criticality belongs to the chiral Ising universality class. The scaling behavior may also be regarded as a quantum, magnetic analogue of the critical Casimir effect which has been widely studied for classical phase transitions.

    ↳ cond-mat.str-elcond-mat.stat-mechhep-phNew J.Phys.(2022)·0 citations
22. 22*

    Constraints on Global Symmetry Breaking in Quantum Gravity from Cosmic Birefringence Measurements

    James Alvey🇬🇧 · Miguel Escudero Abenza🇩🇪

    All global symmetries are expected to be explicitly broken by quantum gravitational effects, and yet may play an important role in Particle Physics and Cosmology. As such, any evidence for a well-preserved global symmetry would give insight into an important feature of gravity. We argue that a recently reported $2.4\sigma$ detection of cosmic birefringence in the Cosmic Microwave Background could be the first observational indication of a well-preserved (although spontaneously broken) global symmetry in nature. A compelling solution to explain this measurement is a very light pseudoscalar field that interacts with electromagnetism. In order for gravitational effects not to lead to large corrections to the mass of this scalar field, we show that the breaking of global symmetries by gravity should be bounded above. Finally, we highlight that any bound of this type would have clear implications for the construction of theories of quantum gravity, as well as for many particle physics scenarios.

    ↳ hep-thastro-ph.COgr-qchep-phPLB(2021)·17 citations
23. 23*

    On Primordial Black Holes and secondary gravitational waves generated from inflation with solo/multi-bumpy potential

    Ruifeng Zheng🇨🇳 · Jiaming Shi🇨🇳 · Taotao Qiu🇨🇳

    It is well known that a primordial black hole (PBH) can be generated in the inflation process of the early universe, especially when the inflation field has a number of non-trivial features that could break the slow-roll condition. In this study, we investigate a toy model of inflation with bumpy potential, which has one or several bumps. We determined that the potential with multi-bump can generate power spectra with multi-peaks in small-scale region, which can in turn predict the generation of primordial black holes in various mass ranges. We also consider the two possibilities of PBH formation by spherical and elliptical collapses. Finally, we discuss the scalar-induced gravitational waves(SIGWs)generated by linear scalar perturbations at second order.

    ↳ astro-ph.COgr-qchep-phhep-thCPC(2022)·61 citations
24. 24*

    Implications of PREX--2 data on the electron--neutrino opacity in dense matter

    Parada T.P. Hutauruk🇰🇷

    Motivated by the recent measurement of the neutron distribution radius of ${}^{208}$Pb from the PREX--2 data, I study the effects of the new G3(M) parameter set constrained by PREX--2 data on the electron--neutrino scattering in dense matter using the extended relativistic mean field (E--RMF) model. I employ the G3(M) parameter set to describe the nuclear matter. The obtained equation of state for the G3(M) parameter set has an excellent agreement with experimental data and the chiral effective field theory calculation with N${}^3$LO 3N forces. I analyze both differential cross section of electron--neutrino and electron--neutrino mean free path to observe their sensitivity to the G3(M) parameter set. One finds that the differential cross sections of electron--neutrino for different baryon densities have higher values compared with that obtained for the TM1e and FSU Garnet parameter sets. The higher cross section decreases the electron--neutrino mean free path.

    ↳ nucl-thastro-ph.HEhep-phPRC(2021)·5 citations
25. 25*

    Ground State Properties of Charmed Hypernuclei with Mean Field Approach

    H. Güven🇫🇷 · K. Bozkurt🇫🇷 · E. Khan🇫🇷 · J. Margueron🇫🇷

    Closed shell charmed hypernuclei ${}_{{\Lambda }_c}^5$Li, ${}_{{\Lambda }_c}^{17}$F, ${}_{{\Lambda }_c}^{41}$Sc, ${}_{{\Lambda }_c}^{57}$Cu, ${}_{{\Lambda }_c}^{133}$Sb and ${}_{{\Lambda }_c}^{209}$Bi are calculated within Hartree-Fock approach by using three different force sets derived from microscopic Brueckner-Hartree-Fock calculations of $\Lambda$ hypernuclei. Ground state properties (binding energies, ${\Lambda }_c$ separation energies, ${\Lambda }_c$ single particle energies and ${\Lambda }_c$ densities) of charmed nuclei are examined. Due to the Coulomb repulsion between protons and the ${\Lambda }_c$ baryon, charmed hypernuclei are most bound for $16\le$A$\le 41$, where ${}_{{\Lambda }_c}^{17}$F can be considered as an excellent candidate to measure charmed hypernuclei. The competition between the attractive nucleon-${\Lambda }_c$ interaction and the Coulomb repulsion is discussed, and we compare $\Lambda$ and ${\Lambda }_c$ hypernuclei properties.

    ↳ nucl-thhep-phnucl-exPRC(2021)·5 citations
26. 26*

    A window on infrared QCD with small expansion parameters

    Marcela Peláez🇺🇾 · Urko Reinosa🇫🇷 · Julien Serreau🇫🇷 · Matthieu Tissier🇫🇷 · Nicolás Wschebor🇺🇾

    Lattice simulations of the QCD correlation functions in the Landau gauge have established two remarkable facts. First, the coupling constant in the gauge sector remains finite and moderate at all scales, suggesting that some kind of perturbative description should be valid down to infrared momenta. Second, the gluon propagator reaches a finite nonzero value at vanishing momentum, corresponding to a gluon screening mass. We review recent studies which aim at describing the long-distance properties of Landau gauge QCD by means of the perturbative Curci-Ferrari model. The latter is the simplest deformation of the Faddeev-Popov Lagrangian in the Landau gauge that includes a gluon screening mass at tree-level. There are, by now, strong evidences that this approach successfully describes many aspects of the infrared QCD dynamics. In particular, several correlation functions were computed at one- and two-loop orders and compared with {\it ab-initio} lattice simulations. The typical error is of the order of ten percent for a one-loop calculation and drops to few percents at two loops. We review such calculations in the quenched approximation as well as in the presence of dynamical quarks. In the latter case, the spontaneous breaking of the chiral symmetry requires to go beyond a coupling expansion but can still be described in a controlled approximation scheme in terms of small parameters. We also review applications of the approach to nonzero temperature and chemical potential.

    ↳ hep-thhep-phRept.Prog.Phys.(2021)·79 citations
27. 27*

    Pseudo-Bounces vs. New Instantons

    J.R. Espinosa🇪🇸 · J. Huertas🇪🇸

    Some false vacua do not decay via bounces. This usually happens when a flat direction of the tunneling action due to scale invariance is lifted to a sloping valley by a scale breaking perturbation, pushing the bounce off to infinity. We compare two types of alternative decay configurations that have been proposed recently to describe decay in such cases: pseudo-bounces and new instantons. Although both field configurations are quite similar, we find that the pseudo-bounce action is lower than the new instanton one and describes more faithfully the bottom of the action valley. In addition, pseudo-bounces cover a range of field space wider than new instantons and, as a result, lead to an action that can be lower than the one for new instantons by orders of magnitude.

    ↳ hep-thhep-phJCAP(2021)·14 citations
28. 28*

    Hubble Expansion and Freeze-Out at RHIC-BES Energies from UrQMD

    Gabriele Inghirami🇩🇪 · Tom Reichert🇩🇪 · Marcus Bleicher🇩🇪

    The freeze-out process in heavy ion collisions is driven by the competition between the scattering rate and the expansion rate of the matter. We analyse the expansion rate $\Theta$ (often called Hubble flow) in relativistic heavy ion collisions in the FAIR and RHIC-BES energy regimes and compare it to the scattering rate $\Gamma$ using the UrQMD transport model. We observe that the time evolution of the system is clearly separated into a compression phase and an expansion phase with time dependent ${\Theta }_{\parallel }$ and ${\Theta }_{\perp }$. The calculated values of the Hubble expansion at kinetic decoupling are in line with previous simple estimates by statistical hadronization models with a Siemens-Rasmussen type emission source. However, the actual shape of the expanding matter is, as expected, found to be between a spherically symmetric and a purely longitudinal expansion. We confirm for the first time in a microscopic simulation that the decoupling hypersurface is indeed determined by the competition of the expansion rate $\Theta$ and the scattering rate $\Gamma$ as suggested previously. This suggests that, in the range of collision energies explored in this study, simple iso-thermal/iso-energy density criteria that are often used in hybrid models to couple hydrodynamic and transport simulations may not capture the true decoupling hyper-surface.

    ↳ nucl-thhep-ph5 citations
29. 29*

    Structure of Kaluza-Klein Graviton Scattering Amplitudes from Gravitational Equivalence Theorem and Double-Copy

    Yan-Feng Hang🇨🇳 · Hong-Jian He🇨🇳

    We study the structure of scattering amplitudes of the Kaluza-Klein (KK) gravitons and of the gravitational KK Goldstone bosons in the compactified 5d General Relativity (GR). We analyze the geometric "Higgs" mechanism for mass-generation of KK gravitons under compactification with a general $R_{\xi }$ gauge-fixing, which is free from the vDVZ discontinuity. Then, we formulate the Gravitational Equivalence Theorem (GRET) to connect the longitudinal KK graviton amplitudes to the KK Goldstone amplitudes, which is a manifestation of the geometric Higgs mechanism at $S$-matrix level. We directly compute the tree-level KK Goldstone amplitudes which equal the longitudinal KK graviton amplitudes in the high energy limit. We further extend the double-copy method with color-kinematics duality to reconstruct the massive KK longitudinal graviton (Goldstone) amplitudes from the KK longitudinal gauge boson (Goldstone) amplitudes in the compactified 5d Yang-Mills (YM) theory under high energy expansion. From these, we reconstruct the GRET of the KK longitudinal graviton (Goldstone) amplitudes in the 5d GR from the KK longitudinal gauge boson (Goldstone) amplitudes in the 5d YM theory. Using either the GRET or the double-copy reconstruction, we provide a theoretical mechanism showing that the sum of all the energy-power terms [up to $O(E^{10})$] in the high-energy four longitudinal KK graviton amplitudes must cancel down to $O(E^2)$ as enforced by matching the energy-power dependence of the corresponding KK Goldstone amplitudes or by matching that of the double-copy amplitudes from the KK YM theory. With the double-copy approach, we establish a new correspondence between the two energy-cancellations: $E^4\to E^0$ in the 5d KK YM theory and $E^{10}\to E^2$ in the 5d KK GR theory. We further analyze the structure of the residual terms in the GRET and uncover a new energy-cancellation mechanism therein.

    ↳ hep-thgr-qchep-phPRD(2022)·25 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.