Wed·Jun 3, 2020Wednesday·June 3, 2020

1. 01*

   Probing the Higgs boson through Yukawa force

   Avik Banerjee🇮🇳 · Gautam Bhattacharyya🇮🇳

   The ATLAS and CMS collaborations of the LHC have observed that the Higgs boson decays into the bottom quark-antiquark pair, and have also established that the Higgs coupling with the top quark-antiquark pair is instrumental in one of the modes for Higgs production. This underlines the discovery of the Yukawa force at the LHC. We demonstrate the impact of this discovery on the Higgs properties that are related to the dynamics of electroweak symmetry breaking. We show that these measurements have considerably squeezed the allowed window for new physics contributing to the Higgs couplings with the weak gauge bosons and the third generation quarks. The expected constraints at the HL-LHC and future Higgs factories are also shown. We project these constraints on the parameter space of a few motivated scenarios beyond the Standard Model. We pick them under two broad categories, namely, the composite Higgs and its RS dual, as well as various types of multi-Higgs models. The latter category includes models with singlet scalars, Type I, II and BGL-type two-Higgs doublet models, and models with scalar triplets a la Georgi and Machacek.

   hep-phhep-exNPB(2020)·12 citations
2. 02*

   Two-parton scattering amplitudes in the Regge limit to high loop orders

   Simon Caron-Huot🇨🇦 · Einan Gardi🇬🇧 · Joscha Reichel🇬🇧 · Leonardo Vernazza🇮🇹

   We study two-to-two parton scattering amplitudes in the high-energy limit of perturbative QCD by iteratively solving the BFKL equation. This allows us to predict the imaginary part of the amplitude to leading-logarithmic order for arbitrary $t$-channel colour exchange. The corrections we compute correspond to ladder diagrams with any number of rungs formed between two Reggeized gluons. Our approach exploits a separation of the two-Reggeon wavefunction, performed directly in momentum space, between a soft region and a generic (hard) region. The former component of the wavefunction leads to infrared divergences in the amplitude and is therefore computed in dimensional regularization; the latter is computed directly in two transverse dimensions and is expressed in terms of single-valued harmonic polylogarithms of uniform weight. By combining the two we determine exactly both infrared-divergent and finite contributions to the two-to-two scattering amplitude order-by-order in perturbation theory. We study the result numerically to 13 loops and find that finite corrections to the amplitude have a finite radius of convergence which depends on the colour representation of the $t$-channel exchange.

   hep-phJHEP(2020)·27 citations
3. 03*

   Explaining $(g-2{)}_{\mu ,e}$, the KOTO anomaly and the MiniBooNE excess in an extended Higgs model with sterile neutrinos

   Bhaskar Dutta🇺🇸 · Sumit Ghosh🇺🇸 · Tianjun Li🇨🇳

   We consider a simple extension of the Standard Model (SM) by a complex scalar doublet and a singlet along with three sterile neutrinos. The sterile neutrinos mix with the SM neutrinos to produce three light neutrino states consistent with the oscillation data and three heavy sterile states. The lightest sterile neutrino has lifetime longer than the age of the Universe and can provide correct dark matter relic abundance. Utilizing tree-level flavor changing interactions of a light scalar with mass~$\sim \mathcal{O}(100)$~MeV along with sterile neutrinos, we can explain the anomalous magnetic moments of both muon and electron, KOTO anomalous events and the MiniBooNE excess simultaneously.

   hep-phPRD(2020)·107 citations
4. 04*

   Dynamical mixing between $2^3{S}_1$ and $1^3{D}_1$ charmed mesons

   Hao Yu🇨🇳 · Ze Zhao🇨🇳 · Ailin Zhang🇨🇳

   In charmed $D$ and $D_s$ mesons sector, the matrix of a Hamiltonian in a quark potential model is computed in the $2^3{S}_1$ and $1^3{D}_1$ subspace. The masses of four mixed states of $2^3{S}_1$ and $1^3{D}_1$ denoted with $D_1^{\ast }(2635)$, $D_1^{\ast }(2739)$, $D_{s1}^{\ast }(2715)$ and $D_{s1}^{\ast }(2805)$ are obtained. It is an off-diagonal part of the spin-orbit tensor interaction that causes the mixing between the $2^3{S}_1$ and $1^3{D}_1$ states. The mixing angles between the $2^3{S}_1$ and $1^3{D}_1$ states are tiny. Under the mixing, a ${}^3{P}_0$ model is employed to compute the hadronic decay widths of all OZI-allowed decay channels of the four mixed states. The two light mixed states $D_1^{\ast }(2635)$ and $D_{s1}^{\ast }(2715)$ are close in mass to $D_J^{\ast }(2600)$ and $D_{s1}^{\ast }(2700)$, while the two heavy mixed states $D_1^{\ast }(2739)$ and $D_{s1}^{\ast }(2805)$ are lighter in mass than $D(2750)$ and $D_{s1}^{\ast }(2860)$. The mixing angles obtained from dynamical interaction are inconsistent with the mixing angles obtained from hadronic decay. Based on mass spectra and hadronic decay analyses, $D_J^{\ast }(2600)$, $D(2750)$, $D_{s1}^{\ast }(2700)$ and $D_{s1}^{\ast }(2860)$ are impossibly the mixed states of $2^3{S}_1$ and $1^3{D}_1$ at the small mixing angles. The inconsistence implies that $D_1^{\ast }(2760)$ and $D_{s1}^{\ast }(2860)$ have not been properly resolved from present experimental data, or there exist large unknown off-diagonal interactions that result in large mixing angles.

   hep-phhep-exPRD(2020)·6 citations
5. 05*

   Searching for GeV-scale Majorana Dark Matter: inter spem et metum

   Adil Jueid🇰🇷 · Salah Nasri🇦🇪 · Rachik Soualah🇦🇪

   We suggest a minimal model for GeV-scale Majorana Dark Matter (DM) coupled to the standard model lepton sector via a charged scalar singlet. We show that there is an anti-correlation between the spin-independent DM-Nucleus scattering cross-section (${\sigma }_{\mathrm{SI}}$) and the DM relic density for parameters values allowed by various theoretical and experimental constraints. Moreover, we find that even when DM couplings are of order unity, ${\sigma }_{\mathrm{SI}}$ is below the current experimental bound but above the neutrino floor. Furthermore, we show that the considered model can be probed at high-energy lepton colliders using e.g. the mono-Higgs production and same-sign charged Higgs pair production.

   hep-phhep-exJHEP(2021)·13 citations
6. 06*

   Bound-free pair production in relativistic nuclear collisions from the NICA to the HE LHC colliders

   D.A. Bauer🇺🇸 · D.V. Karlovets🇷🇺 · V.G. Serbo🇷🇺

   We consider the electron-positron pair production in relativistic heavy ion collisions, in which the produced electron is captured by one of the nuclei resulting, thus, in the formation of a hydrogen--like ion. These ions emerge from the collision point and hit the vacuum chamber wall inside superconducting magnets. Therefore, this process may be important for the problems of beam life time and for the quenching the irradiated magnet. A theoretical investigation for such a bound-free pair production (BFPP) at the colliders from NICA to HE LHC is presented. We obtain an approximate universal formula for the total cross section of the process. We compare it with the results of available numerical calculations and estimate that an accuracy of our calculations is better than $30$ % at the energies of the NICA collider and becomes of the order of a few percent for the RHIC and HE LHC colliders. Based on the obtained results, the detailed calculations are performed for future experiments at the NICA collider. We find that the expected BFPP cross sections for the Au${}^{79+}$-Au${}^{79+}$ and Bi${}^{83+}$-Bi${}^{83+}$ collisions are in the range from $10$ to $70$ barn, while for the p-Au${}^{79+}$ and p-Bi${}^{83+}$ collisions they are in the range of a few mbarn.

   hep-phnucl-thEPJA(2020)·9 citations
7. 07*

   Gravitational waves from breaking of an extra $U(1)$ in $SO(10)$ grand unification

   Nobuchika Okada🇺🇸 · Osamu Seto🇯🇵 · Hikaru Uchida🇯🇵

   In a class of gauged $U(1)$ extended Standard Models (SMs), the breaking of the $U(1)$ symmetry is not only a source for Majorana masses of right-handed (RH) neutrinos crucial for the seesaw mechanism, but also a source of stochastic gravitational wave (GW) background. Such $U(1)$ extended models are well-motivated from the viewpoint of grand unification. In this paper, we discuss a successful ultraviolet completion of a $U(1)$ extended SM by an $SO(10)$ grand unified model through an intermediate step of $SU(5)\times U(1)$ unification. With a parameter set that is compatible with the $SO(10)$ grand unification, we find that a first-order phase transition associated with the $U(1)$ symmetry breaking can be strong enough to generate GWs with a detectable size of amplitude. We also find that the resultant GW amplitude reduces and its peak frequency becomes higher as the RH neutrino masses increase.

   hep-phastro-ph.COPTEP(2021)·27 citations
8. 08*

   Chiral Perturbation Theory at NNNLO

   Nils Hermansson-Truedsson🇨🇭

   Chiral perturbation theory is a much successful effective field theory of quantum chromodynamics at low energies. The effective Lagrangian is constructed systematically order by order in powers of the momentum $p^2$, and until now the leading order (LO), next-to leading order (NLO), next-to-next-to leading order (NNLO) and next-to-next-to-next-to leading order (NNNLO) have been studied. In the following review we consider the construction of the Lagrangian and in particular focus on the NNNLO case. We in addition review and discuss the pion mass and decay constant at the same order, which are fundamental quantities to study for chiral perturbation theory. Due to the large number of terms in the Lagrangian and hence low energy constants arising at NNNLO, some remarks are made about the predictivity of this effective field theory.

   hep-phSymmetry(2020)·11 citations
9. 09*

   Numerical analysis of neutrino physics within a high scale supersymmetry model via machine learning

   Ying-Ke Lei🇨🇳 · Chun Liu🇨🇳 · Zhiqiang Chen🇨🇳

   A machine learning method is applied to analyze lepton mass matrices numerically. The matrices were obtained within a framework of high scale SUSY and a flavor symmetry, which are too complicated to be solved analytically. In this numerical calculation, the heuristic method in machine learning is adopted. Neutrino masses, mixings, and CP violation are obtained. It is found that neutrinos are normally ordered and the favorable effective Majorana mass is about $7\times 10^{-3}$ eV.

   hep-phMod.Phys.Lett.A(2020)·2 citations
10. 10*

    Production of axial-vector mesons at $e^{+}{e}^{-}$ collisions with double-tagging as a way to constrain the axial meson LbL contribution to muon g-2 and/or hyperfine splitting of muonic hydrogen

    Antoni Szczurek🇵🇱

    We calculate cross sections for production of axial-vector $f_1(1285)$ mesons for double-tagged measurements of the $e^{+}{e}^{-}\to e^{+}{e}^{-}{f}_1(1285)$ reaction. Different ${\gamma }^{\ast }{\gamma }^{\ast }\to f_1(1285)$ vertices from the literature are used. Both integrated cross section as well as differential distributions are calculated. Predictions for a potential measurement at Belle II are presented. Quite different results are obtained for the different vertices proposed in the literature. Future measurements at $e^{+}{e}^{-}$ colliders could test and/or constrain the ${\gamma }^{\ast }{\gamma }^{\ast }\to f_1(a_1,f_1^{\prime })$ vertices and associated form factors, known to be important ingredients for calculating contributions to anomalous magnetic moment of muon and hyperfine splitting of levels of muonic atoms.

    hep-phhep-exPRD(2020)·12 citations
11. 11*

    Heavy quark correlators in Instanton Liquid Model with perturbative corrections

    M. Musakhanov (1)🇺🇿 · N. Rakhimov (1)🇺🇿 · U.T. Yakhshiev (1,2,3) ((1) National University of Uzbekistan, (2) Inha University, (3) Institute of Nuclear Physics, AS RUz)🇰🇷

    In the present work we consider the influence on the heavy quark correlators due to the instanton background in the framework of instanton liquid model (ILM) of QCD vacuum by taking into account also the perturbative gluon effects. For a single heavy quark this leads to the mass shift due to the direct-instanton nonperturbative and ILM modified perturbative contributions, respectively. In the heavy quark-antiquark ($Q\bar{Q}$) sector we obtain the potential consisting the direct instanton induced part and the one-gluon exchange (OGE) perturbative part which is screened at large distances due to the nonperturbative dynamics. At the region of interest corresponding to the heavy quark physics the screening effect in OGE can be well approximated by a Yukawa-type potential in terms of the dynamically generated gluon mass. A possible implication of the present studies to the phenomenology of heavy quarkonium is also discussed.

    hep-phhep-thPRD(2020)·12 citations
12. 12*

    Charged charm stars

    V. P. Goncalves🇧🇷 · L. Lazzari🇧🇷

    The study of the general properties and stability of charm stars with a net electric charge is performed within the MIT bag model framework. We consider two different models for the electric charge distribution and demostrate that both imply stellar configurations with larger masses and that satisfy the equilibrium condition. The dynamical stability against radial oscillations is investigated. Our results demonstrate that the eigenfrequencies are modified by the presence of a net electric charge, but the instability, previously demonstrated for the electrically neutral case, is also present in charged charm stars.

    hep-phastro-ph.HEnucl-thNPA(2020)·1 citation
13. 13*

    Mu-Tau Reflection Symmetry in the Standard Parametrization and Contributions from Charged Lepton Sector

    Chandan Duarah🇮🇳

    The $\mu -\tau$ reflection symmetry of the lepton mixing matrix accommodates maximal atmospheric mixing (${\theta }_{23}=\pi /4$) as well as maximal Dirac CP phase ($\delta =\pm \pi /2$) for the Dirac case. In the standard parametrization of the PMNS matrix the reflection symmetric nature is not directly visible while substituting the maximal values of the mixing parameters. This issue has been addressed in this paper. It is found that the reflection symmetry in the 'standard' PMNS matrix can be restored by allowing maximal values of the Majorana CP phases ($\alpha$, $\beta$) as well, along with maximal $\delta$. To accommodate non-maximal values of ${\theta }_{23}$ and $\delta$ we consider charged lepton contributions to the neutrino mixing and implement the proposed scheme of reflection symmetry in the neutrino mixing matrix. The charged lepton correction scheme succeeds in the prediction of lepton mixing parameters consistent with the global $3\nu$ oscillation data.

    hep-phPLB(2021)·21 citations
14. 14*

    Mapping reactor neutrino spectra from TAO to JUNO

    Francesco Capozzi🇩🇪 · Eligio Lisi🇮🇹 · Antonio Marrone🇮🇹

    The Jiangmen Underground Neutrino Observatory (JUNO) project aims at probing, at the same time, the two main frequencies of three-flavor neutrino oscillations, as well as their interference related to the mass ordering (normal or inverted), at a distance of ~53 km from two powerful reactor complexes in China, at Yangjiang and Taishan. In the latter complex, the unoscillated spectrum from one reactor core is planned to be closely monitored by the Taishan Antineutrino Observatory (TAO), expected to have better resolution (x 1/2) and higher statistics (x 30) than JUNO. In the context of neutrino energy spectra endowed with fine-structure features from summation calculations, we analyze in detail the effects of energy resolution and nucleon recoil on observable event spectra. We show that a model spectrum in TAO can be mapped into a corresponding spectrum in JUNO through appropriate convolutions. The mapping is exact in the hypothetical case without oscillations, and holds to a very good accuracy in the real case with oscillations. We then analyze the sensitivity to mass ordering of JUNO (and its precision oscillometry capabilities) assuming a single reference spectrum, as well as bundles of variant spectra, as obtained by changing nuclear input uncertainties in summation calculations from a publicly available toolkit. We show through a chi-squared analysis that variant spectra induce little reduction of the sensitivity in JUNO, especially when TAO constraints are included. Subtle aspects of the statistical analysis of variant spectra are also discussed.

    hep-phhep-exnucl-exnucl-thPRD(2020)·17 citations
15. 15*

    Identifying groomed jet splittings in heavy-ion collisions

    James Mulligan🇺🇸 · Mateusz Ploskon🇺🇸

    Measurements of jet substructure in heavy-ion collisions may provide key insight to the nature of jet quenching in the quark-gluon plasma. Jet grooming techniques from high-energy physics have been applied to heavy-ion collisions in order to isolate theoretically controlled jet observables and explore possible modification to the hard substructure of jets. However, the grooming algorithms used have not been tailored to the unique considerations of heavy-ion collisions, in particular to the experimental challenge of reconstructing jets in the presence of a large underlying event. We report a set of simple studies illustrating the impact of the underlying event on identifying groomed jet splittings in heavy-ion collisions, and on associated groomed jet observables. We illustrate the importance of the selection of grooming algorithm, as certain groomers are more robust to these effects, while others, including those commonly used in heavy-ion collisions, are susceptible to large background effects -- which, when uncontrolled, can mimic a jet quenching signal. These experimental considerations, along with appropriate theoretical motivation, provide input to the choice of grooming algorithms employed in heavy-ion collisions.

    hep-phnucl-exPRC(2020)·45 citations
16. 16*

    Global symmetries, hidden sectors and emergent (dark) vector interactions

    Panagiotis Betzios🇬🇷 · Elias Kiritsis🇬🇷 · Vasilis Niarchos🇬🇷 · Olga Papadoulaki🇮🇹

    Hidden theories coupled to the SM may provide emergent (dark) vectors, that are composites/bound-states of the hidden fields. This is motivated by paradigms emerging from the AdS/CFT correspondence but it is a more general phenomenon. We explore the general setup and find that UV interactions among currents or charged fields give rise to emergent vectors in the IR. We study the general properties of such vectors and argue that they can be generically different from fundamental dark photons that have been studied so far.

    hep-phhep-thJHEP(2020)·11 citations
17. 17*

    Higgsino and gaugino pair production at the LHC with aNNLO+NNLL precision

    J. Fiaschi🇩🇪 · M. Klasen🇩🇪

    We present a calculation of higgsino and gaugino pair production at the LHC at next-to-next-to-leading logarithmic (NNLL) accuracy, matched to approximate next-to-next-to-leading order (aNNLO) QCD corrections. We briefly review the formalism for the resummation of large threshold logarithms and highlight the analytical results required at aNNLO+NNLO accuracy. Our numerical results are found to depend on the mass and nature of the produced charginos and neutralinos. The differential and total cross sections for light higgsinos, which like sleptons are produced mostly at small x and in the s-channel, are found to be again moderately increased with respect to our previous results. The differential and total cross sections for gauginos are, however, not increased any more due to the fact that gauginos, like squarks, are now constrained by ATLAS and CMS to be heavier than about 1 TeV, so that also t- and u-channels play an important role. The valence quarks probed at large x then also induce substantially different cross sections for positively and negatively charged gauginos. The higgsino and gaugino cross sections are both further stabilized at aNNLO+NNLL with respect to the variation of renormalization and factorization scales. We also now take mixing in the squark sector into account and study the dependence of the total cross sections on the squark and gluino masses as well as the trilinear coupling controlling the mixing in particular in the sbottom sector.

    hep-phhep-exPRD(2020)·15 citations
18. 18*

    BBN constraints on dark radiation isocurvature

    Peter Adshead🇺🇸 · Gilbert Holder🇺🇸 · Pranjal Ralegankar🇺🇸

    The existence of dark radiation that is completely decoupled from the standard model in the early Universe leaves open the possibility of an associated dark radiation isocurvature mode. We show that the presence of dark radiation isocurvature leads to spatial variation in the primordial abundances of helium and deuterium due to spatial variation in $N_{\mathrm{eff}}$ during Big Bang nucleosynthesis. We use the result to constrain the existence of such an isocurvature mode on scales down to $\sim 1$ Mpc scales. By measuring the excess variance in the primordial helium to hydrogen and deuterium to hydrogen ratio in different galaxies, we constrain the variance in average isocurvature in a galaxy to be less than $0.13/\Delta {\bar{N}}_{\mathrm{eff}}$ at 95\% confidence. Here $\Delta {\bar{N}}_{\mathrm{eff}}$ is the spatially averaged increase in $N_{\mathrm{eff}}$ due to the additional dark radiation component.

    ↳ astro-ph.COhep-phJCAP(2020)·15 citations
19. 19*

    Antimatter as Macroscopic Dark Matter

    Jagjit Singh Sidhu🇺🇸 · Robert J. Scherrer🇺🇸 · Glenn Starkman🇺🇸

    Antimatter macroscopic dark matter (macros) refers to a generic class of antimatter dark matter candidates that interact with ordinary matter primarily through annihilation with large cross-sections. A combination of terrestrial, astrophysical, and cosmological observations constrain a portion of the anti-macro parameter space. However, a large region of the parameter space remains unconstrained, most notably for nuclear-dense objects.

    ↳ astro-ph.COhep-exhep-phPLB(2020)·25 citations
20. 20*

    S-wave kaon-nucleon potentials with all-to-all propagators in the HAL QCD method

    Kotaro Murakami🇯🇵 · Yutaro Akahoshi🇯🇵 · Sinya Aoki🇯🇵

    In this paper, employing an all-to-all quark propagator technique, we investigate the kaon-nucleon interactions in lattice QCD. We calculate the S-wave kaon-nucleon potentials at the leading order in the derivative expansion in the time-dependent HAL QCD method, using (2+1)-flavor gauge configurations at the lattice spacing $a\approx 0.09$ fm on $32^3\times 64$ lattices and the pion mass $m_{\pi }\approx 570$ MeV. We take the one-end trick for all-to-all propagators, which allows us to put the zero momentum hadron operators at both source and sink and to smear quark operators at the source. We find the stronger repulsive interaction in the $I=1$ channel than in the $I=0$. The phase shifts obtained by solving the Schrödinger equations with the potentials qualitatively reproduce the energy dependence of the experimental phase shifts, and have the similar behavior to the previous results from lattice QCD without all-to-all propagators. Our study demonstrates that the all-to-all quark propagator technique with the one-end trick is useful to study interactions for meson-baryon systems in the HAL QCD method, so that we will apply it to meson-baryon systems which contain quark-antiquark creation/annihilation processes in our future studies.

    ↳ hep-lathep-phnucl-thPTEP(2020)·7 citations
21. 21*

    From weak to strong: constrained extrapolation of perturbation series with applications to dilute Fermi systems

    C. Wellenhofer🇩🇪 · D. R. Phillips🇺🇸 · A. Schwenk🇩🇪

    We develop a method that uses truncation-order-dependent re-expansions constrained by generic strong-coupling information to extrapolate perturbation series to the nonperturbative regime. The method is first benchmarked against a zero-dimensional model field theory and then applied to the dilute Fermi gas in one and three dimensions. Overall, our method significantly outperforms Padé and Borel extrapolations in these examples. The results for the ground-state energy of the three-dimensional Fermi gas are robust with respect to changes of the form of the re-expansion and compare well with quantum Monte Carlo simulations throughout the BCS regime and beyond.

    ↳ cond-mat.quant-gashep-phnucl-thPRResearch(2020)·8 citations
22. 22*

    Cosmological parameter estimation for dynamical dark energy models with future fast radio burst observations

    Ze-Wei Zhao🇨🇳 · Zheng-Xiang Li🇨🇳 · Jing-Zhao Qi🇨🇳 · He Gao🇨🇳 · Jing-Fei Zhang🇨🇳 · Xin Zhang🇨🇳

    Fast radio bursts (FRBs) are a mysterious astrophysical phenomenon of bright pulses emitted at radio frequencies, and they are expected to be frequently detected in the future. The dispersion measures of FRBs are related to cosmological parameters, thus FRBs have the potential to be developed into a new cosmological probe if their data can be largely accumulated in the future. In this work, we study the capability of future FRB data to improve cosmological parameter estimation in two dynamical dark energy models. We find that the simulated FRB data can break the parameter degeneracies inherent in the current cosmic microwave background (CMB) data. Therefore, the combination of the CMB and FRB data can significantly improve the constraints on the Hubble constant and dark energy parameters, compared to those using CMB or FRB alone. If 10,000 FRB events with known redshifts are detected in the future, they would perform better than the baryon acoustic oscillation (BAO) data in breaking the parameter degeneracies inherent in the CMB data. We also find that the combination of FRB and gravitational-wave (GW) standard siren data provides an independent low-redshift probe to verify the results from the CMB and BAO data. For the data combination of CMB, GW, and FRB, it is found that the main contribution to the constraints comes from the CMB and GW data, but the inclusion of the FRB data still can evidently improve the constraint on the baryon density.

    ↳ astro-ph.COgr-qchep-phApJ(2020)·64 citations
23. 23*

    Deconfinement and CP-breaking at $\theta =\pi$ in Yang-Mills theories and a novel phase for SU(2)

    Shi Chen🇯🇵 · Kenji Fukushima🇯🇵 · Hiromichi Nishimura🇯🇵 · Yuya Tanizaki🇯🇵

    We discuss the deconfinement and the CP-breaking phase transitions at $\theta =\pi$ in Yang-Mills theories. The 't Hooft anomaly matching prohibits the confined phase with CP symmetry and requires $T_{dec}(\theta =\pi )\le T_{CP}$, where $T_{dec}(\theta =\pi )$ and $T_{CP}$ denote the deconfinement and the CP-restoration temperatures, respectively, at $\theta =\pi$. We analytically study these two phase transitions in softly-broken $\mathcal{N}=1$ supersymmetric Yang-Mills theories on small ${\mathbb{R}}^3\times S^1$ with the periodic boundary condition for gluinos. For most gauge groups except SU(2) in this model, we find that the inequality is saturated, so deconfinement and CP restoration occur simultaneously. We demonstrate special features of the SU(2) gauge theory: There is a finite window of two temperatures, $T_{dec}(\pi )<T_{CP}$, which indicates the existence of a novel CP-broken deconfined phase. We also discuss an implication of the novel phase for domain walls and their junctions.

    ↳ hep-thhep-phPRD(2020)·29 citations
24. 24*

    More on Effective Potentials for Revolving D-Branes

    Satoshi Iso🇯🇵 · Noriaki Kitazawa🇯🇵 · Hikaru Ohta🇯🇵 · Takao Suyama🇯🇵

    We continue to investigate the effective potential between a pair of D$p$-branes revolving around each other by using the technique of $partialmodulartransformation$ developed in our previous work. We determine the shape of the potential for general $p$ for a wide range of regions interpolating smaller and larger distances than the string scale $l_s$. We also discuss the backreaction of the D-brane system to the space-time metric and the validity of our calculations.

    ↳ hep-thhep-phJHEP(2020)·1 citation
25. 25*

    Near-BPS baby Skyrmions

    Sven Bjarke Gudnason🇨🇳 · Marco Barsanti🇮🇹 · Stefano Bolognesi🇮🇹

    We consider the baby-Skyrme model in the regime close to the so-called restricted baby-Skyrme model, which is a BPS model with area-preserving diffeomorphism invariance. The perturbation takes the form of the standard kinetic Dirichlet term with a small coefficient $ϵ$. Classical solutions of this model, to leading order in $ϵ$, are called restricted harmonic maps. In the BPS limit ($ϵ\to 0$) of the model with the potential being the standard pion-mass term, the solution with unit topological charge is a compacton. Using analytical and numerical arguments we obtain solutions to the problem for topological sectors greater than one. We develop a perturbative scheme in $ϵ$ with which we can calculate the corrections to the BPS mass. The leading order ($\mathcal{O}({ϵ}^1)$) corrections show that the baby Skyrmion with topological charge two is energetically preferred. The binding energy requires us to go to the third order in $ϵ$ to capture the relevant terms in perturbation theory, however, the binding energy contributes to the total energy at order ${ϵ}^2$. We find that the baby Skyrmions - in the near-BPS regime - are compactons of topological charge two, that touch each other on their periphery at a single point and with orientations in the attractive channel.

    ↳ hep-thhep-phJHEP(2020)·13 citations
26. 26*

    Cosmological constraints on non-adiabatic dark energy perturbations

    Rubén Arjona🇪🇸 · Juan García-Bellido🇪🇸 · Savvas Nesseris🇪🇸

    The exact nature of dark energy is currently unknown and its cosmological perturbations, when dark energy is assumed not to be the cosmological constant, are usually modeled as adiabatic. Here we explore the possibility that dark energy might have a nonadiabatic component and we examine how it would affect several key cosmological observables. We present analytical solutions for the growth rate and growth index of matter density perturbations and compare them to both numerical solutions of the fluid equations and an implementation in the Boltzmann code CLASS, finding that they all agree to well below one percent. We also perform a Monte Carlo analysis to derive constraints on the parameters of the nonadiabatic component using the latest cosmological data, including the temperature and polarization spectra of the Cosmic Microwave Background as observed by Planck, the Baryon Acoustic Oscillations, the Pantheon type Ia supernovae compilation and lastly, measurements of Redshift Space Distortions (RSD) of the growth rate of matter perturbations. We find that the amplitude of the nonadiabatic pressure perturbation is consistent with zero within $1\sigma$. Finally, we also present a new, publicly available, RSD likelihood for MontePython based on the "Gold 2018" growth rate data compilation.

    ↳ astro-ph.COgr-qchep-phPRD(2020)·30 citations
27. 27*

    ETHOS -- An effective parametrization and classification for structure formation: the non-linear regime at $z\gtrsim 5$

    Sebastian Bohr (1)🇮🇸 · Jesús Zavala (1)🇮🇸 · Francis-Yan Cyr-Racine (2)🇺🇸 · Mark Vogelsberger (3)🇺🇸 · Torsten Bringmann (4)🇳🇴 · Christoph Pfrommer (5) ((1) University of Iceland, (2) UNM, (3) MIT, (4) UIO, (5) AIP)🇩🇪

    We propose two effective parameters that fully characterise galactic-scale structure formation at high redshifts ($z\gtrsim 5$) for a variety of dark matter (DM) models that have a primordial cutoff in the matter power spectrum. Our description is within the recently proposed ETHOS framework and includes standard thermal Warm DM (WDM) and models with dark acoustic oscillations (DAOs). To define and explore this parameter space, we use high-redshift zoom-in simulations that cover a wide range of non-linear scales from those where DM should behave as CDM ($k\sim 10h{\mathrm{Mpc}}^{-1}$), down to those characterised by the onset of galaxy formation ($k\sim 500h{\mathrm{Mpc}}^{-1}$). We show that the two physically motivated parameters $h_{\mathrm{peak}}$ and $k_{\mathrm{peak}}$, the amplitude and scale of the first DAO peak, respectively, are sufficient to parametrize the linear matter power spectrum and classify the DM models as belonging to effective non-linear structure formation regions. These are defined by their relative departure from Cold DM ($k_{\mathrm{peak}}\to \infty$) and WDM ($h_{\mathrm{peak}}=0$) according to the non-linear matter power spectrum and halo mass function. We identify a region where the DAOs still leave a distinct signature from WDM down to $z=5$, while a large part of the DAO parameter space is shown to be degenerate with WDM. Our framework can then be used to seamlessly connect a broad class of particle DM models to their structure formation properties at high redshift without the need of additional $N$-body simulations.

    ↳ astro-ph.COhep-phMNRAS(2020)·37 citations
28. 28*

    Intricacies of classical de Sitter string backgrounds

    David Andriot🇦🇹 · Paul Marconnet🇫🇷 · Timm Wrase🇦🇹

    Up-to-date, there is no known example of a classical de Sitter solution of string theory, despite several good candidates. We consider here two newly discovered 10d supergravity de Sitter solutions, and analyse in great detail whether they can be promoted to classical string backgrounds. To that end, we identify five requirements to be met, and develop the necessary 10d tools to test the solutions. Eventually, they both fail to verify simultaneously all requirements, in spite of positive partial results. The explicit values obtained offer a clear illustration of the situation, and the analysis highlights various subtleties. We finally discuss the relation to the problem of scale separation.

    ↳ hep-thgr-qchep-phPLB(2021)·38 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.