Tue·Aug 11, 2020Tuesday·August 11, 2020

1. 01*

   Deep learnig analysis of the inverse seesaw in a 3-3-1 model at the LHC

   D. Cogollo🇧🇷 · F. F. Freitas🇵🇹 · C. A. de S. Pires🇧🇷 · Yohan M. Oviedo-Torres🇧🇷 · P. Vasconcelos🇧🇷

   Inverse seesaw is a genuine TeV scale seesaw mechanism. In it active neutrinos with masses at eV scale requires lepton number be explicitly violated at keV scale and the existence of new physics, in the form of heavy neutrinos, at TeV scale. Therefore it is a phenomenologically viable seesaw mechanism since its signature may be probed at the LHC. Moreover it is successfully embedded into gauge extensions of the standard model as the 3-3-1 model with the right-handed neutrinos. In this work we revisit the implementation of this mechanism into the 3-3-1 model and employ deep learning analysis to probe such setting at the LHC and, as main result, we have that if its signature is not detected in the next LHC running with energy of 14 TeVs, then, the vector boson $Z^{\prime }$ of the 3-3-1 model must be heavier than 4 TeVs.

   hep-phPLB(2020)·15 citations
2. 02*

   Confining potential under the gauge field condensation in the SU(2) Yang-Mills theory

   Hirohumi Sawayanagi🇯🇵

   $Q\bar{Q}$ potential is studied in the SU(2) gauge theory. Based on the nonlinear gauge of the Curci-Ferrari type, the possibility of a gluon condensation $⟨A_{\mu }^{+}{A}_{\mu }^{-}⟩$ in low-energy region has been considered at the one-loop level. Instead of the magnetic monopole condensation, this condensation makes classical gluons massive, and can yield a linear potential. We show this potential consists of the Coulomb plus linear part and an additional part. Comparing with the Cornell potential, we study this confining potential in detail, and find that the potential has two implicit scales $r_c$ and ${\tilde{R}}_0$. The meanings of these scales are clarified. We also show that the Cornell potential that fits well to this confining potential is obtained by taking these scales into account.

   hep-phPTEP(2021)·1 citation
3. 03*

   Axial and pseudoscalar form factors from charged current quasielastic neutrino-nucleon scattering

   Oleksandr Tomalak🇺🇸

   We study the scattering of neutrinos on polarized and unpolarized free nucleons, and also the polarization of recoil particles in these scatters. In contrast to electromagnetic processes, the parity-violating weak interaction gives rise to large spin asymmetries at leading order. Future polarization measurements could provide independent access to the proton axial structure and allow the first extraction of the pseudoscalar form factor from neutrino data without the conventional partially conserved axial current (PCAC) ansatz and assumptions about the pion-pole dominance. The pseudoscalar form factor can be accessed with precise measurements with muon (anti)neutrinos of a few hundreds $\mathrm{MeV}$ of energy or with tau (anti)neutrinos. The axial form factor can be extracted from scattering measurements using accelerator neutrinos of all energies.

   hep-phhep-exnucl-exnucl-thPRD(2021)·15 citations
4. 04*

   Exploring the Collective Phenomenon at the Electron-Ion Collider

   Yu Shi🇨🇳 · Lei Wang🇨🇳 · Shu-Yi Wei🇮🇹 · Bo-Wen Xiao🇨🇳 · Liang Zheng🇨🇳

   Based on rare fluctuations in strong interactions, we argue that there is a strong physical resemblance between the high multiplicity events in photo-nuclear collisions and those in $pA$ collisions, in which interesting long range collective phenomena are discovered. This indicates that the collectivity can also be studied in certain kinematic region of the upcoming Electron-Ion Collider (EIC) where the incoming virtual photon has a sufficiently long lifetime. Using a model in the Color Glass Condensate formalism, we first show that the initial state interactions can explain the recent ATLAS azimuthal correlation results measured in the photo-nuclear collisions, and then we provide quantitative predictions for the long range correlations in $eA$ collisions in the EIC regime. With the unprecedented precision and the ability to change the size of the collisional system, the high luminosity EIC will open a new window to explore the physical mechanism responsible for the collective phenomenon.

   hep-phhep-exnucl-exnucl-thPRD(2021)·23 citations
5. 05*

   Flavor and CP-violating Higgs sector in two Higgs doublet models with $U(1{)}^{\prime }$

   Ligong Bian🇨🇳 · Hyun Min Lee🇰🇷 · Chan Beom Park🇰🇷

   We investigate the role of a local $U(1{)}^{\prime }$ symmetry for the problem of CP violation in the effective theory for two Higgs doublet models and its microscopic counterparts. First, in two Higgs doublet models with $U(1{)}^{\prime }$, we show that the higher-dimensional operators in the scalar potential violate the CP symmetry with an interplay with the mixing mass parameter, giving rise to small mixings between CP-even and CP-odd scalars. Motivated by the $B$-meson anomalies in recent years, we take the flavored $U(1{)}^{\prime }$ to be a benchmark model for specifying the flavor structure. Then, we calculate the electric dipole moment of electron (eEDM) at two loops due to the CP-violating higher-dimensional operators and identify the correlation between the masses of heavy Higgs bosons and the cutoff scale from the bound on eEDM. We also comment on the possibility of making an independent test of the CP violation in the collider searches for heavy Higgs bosons. Finally, we show how the obtained eEDM results in the effective theory can be used to constrain microscopic models with an explicit CP violation in the partially decoupled or dark sectors.

   hep-phJ.Korean Phys.Soc.(2021)·5 citations
6. 06*

   Chirality Production with Mass Effects-Schwinger Pair Production and the Axial Ward Identity

   Patrick Copinger🇯🇵 · Shi Pu🇨🇳

   The anomalous generation of chirality with mass effects via the axial Ward identity and its dependence on the Schwinger mechanism is reviewed, utilizing parity violating homogeneous electromagnetic background fields. The role vacuum asymptotic states play on the interpretation of expectation values is examined. It is discussed that observables calculated with an in-out scattering matrix element predict a scenario under Euclidean equilibrium. A notable ramification of which is a vanishing of the chiral anomaly. In contrast, it is discussed observables calculated under an in-in, or real-time, formalism predict a scenario out-of equilibrium, and capture effects of mean produced particle anti-particle pairs due to the Schwinger mechanism. The out-of equilibrium chiral anomaly is supplemented with exponential quadratic mass suppression as anticipated for the Schwinger mechanism. Similar behavior in and out-of equilibrium is reviewed for applications including the chiral magnetic effect and chiral condensate.

   hep-phhep-thnucl-thInt.J.Mod.Phys.A(2020)·23 citations
7. 07*

   Data-driven Estimation of Background Distribution through Neural Autoregressive Flows

   Suyong Choi🇰🇷 · Jaehoon Lim🇰🇷 · Hayoung Oh🇰🇷

   We report on a general and automatic data-driven background distribution shape estimation method using neural autoregressive flows (NAF), which is one of the deep generative learning methods. Data-driven background estimation is indispensable for many analyses involving complicated final states where reliable predictions are not available. NAF allow us to construct general bijective transformations that operate on multidimensional space, out of finite number of invertible one-dimensional functions. Given its simplicity and universality, it is well suited to the application in the data-driven background estimation, since data-driven estimations can be expressed as transformations. In a data-driven background estimation, the goal is to derive appropriate transformations and apply extrapolated transformations to the region of interest. In the ABCDnn method, we can have the NAF learn the transformations' dependence on control variables by having multiple control regions. We demonstrate that the prediction through ABCDnn method is similar to optimal case, while having smaller statistical uncertainty.

   hep-phhep-ex24 citations
8. 08*

   Factorization and its Breaking in Dijet Single Transverse Spin Asymmetries in $pp$ Collisions

   Xiaohui Liu🇨🇳 · Felix Ringer🇺🇸 · Werner Vogelsang🇩🇪 · Feng Yuan🇺🇸

   We study factorization in single transverse spin asymmetries for dijet production in proton-proton collisions, by considering soft gluon radiation at one-loop order. We show that the associated transverse momentum dependent (TMD) factorization is valid at the leading logarithmic level. At next-to-leading-logarithmic (NLL) accuracy, however, we find that soft gluon radiation generates terms in the single transverse spin dependent cross section that differ from those known for the unpolarized case. As a consequence, these terms cannot be organized in terms of a spin independent soft factor in the factorization formula. We present leading logarithmic predictions for the single transverse spin dijet asymmetry for $pp$ collisions at RHIC, based on quark Sivers functions constrained by semi-inclusive deep inelastic scattering data. We hope that our results will contribute to a better understanding of TMD factorization breaking effects at NLL accuracy and beyond.

   hep-phhep-exnucl-exPRD(2020)·11 citations
9. 09*

   Magnetic moments of the octet, decuplet, low-lying charm, and low-lying bottom baryons in a nuclear medium

   Kazuo Tsushima🇧🇷

   We study the magnetic moments of the octet, decuplet, low-lying charm, and low-lying bottom baryons with nonzero light quarks in symmetric nuclear matter using the quark-meson coupling (QMC) model, which satisfies the constraint for the allowed maximum change (swelling) of the in-medium nucleon size derived from the $y$-scaling data for ${}^3$He$(e,e^{\prime })$ and ${}^{56}$Fe$(e,e^{\prime })$. The present QMC model also satisfies the expected allowed maximum enhancement of the nucleon magnetic moments in nuclear matter. Moreover, it has been proven that the calculated in-medium to free proton electromagnetic form factor (EMFF) ratios calculated within the QMC model, reproduce well the proton EMFF super ratio extracted from ${}^4\mathrm{He}(\vec{e},e^{\prime }\vec{p}{)}^3\mathrm{H}$ at Jefferson Laboratory (JLab). The medium modifications of the magnetic moments are estimated by evaluating the in-medium to free space baryon magnetic moment ratios to compensate the MIT bag deficiency to describe the free space octet baryon magnetic moments, where ratios are often measured directly in experiments even without knowing the absolute values, such as the free and bound proton electromagnetic form factors, as well as the European Muon Collaboration (EMC) effect to extract the structure function $F_2$ ratio of the bound to free nucleons by the corresponding cross section ratio. We also present the results calculated with the different current quark mass values for the strange and bottom quarks to see the possible impact. Furthermore, for a practical use, we give the explicit density dependent parametrizations for the vector potentials of the baryons and light-$(u,d)$ quarks, as well as for the effective masses of the baryons treated in this study, and of the mesons, $\omega ,\rho ,K,K^{\ast },\eta ,{\eta }^{\prime },D,D^{\ast },B$, and $B^{\ast }$.

   hep-phastro-ph.HEhep-exnucl-ex+1PTEP(2022)·34 citations
10. 10*

    Investigation of $qqqs\bar{q}$ pentaquarks in a chiral quark model

    Liting Qin🇨🇳 · Yue Tan🇨🇳 · Xiaohuang Hu🇨🇳 · Jialun Ping🇨🇳

    We investigate the pentaquark system $qqqs\bar{q}$ in a framework of chiral quark model. Two structures, $(qqq)(s\bar{q})$ and $(qqs)(q\bar{q})$, with all possible color, spin, flavor configurations are considered. The calculations show that there are several possible resonance states, $Sigma\pi$ and $N\bar{K}$ state with $I{J}^P=0{\frac{1}{2}}^{-}$, ${\Sigma }^{\ast }\pi$ with $I{J}^P=0{\frac{3}{2}}^{-}$, ${\Sigma }^{\ast }\rho$ with $I{J}^P=0{\frac{5}{2}}^{-}$, $\Delta \bar{K}$ with $I{J}^P=1{\frac{3}{2}}^{-}$ and $\Delta {\bar{K}}^{\ast }$ with $I{J}^P=1{\frac{5}{2}}^{-}$. Where the $N\bar{K}$ state with $I{J}^P=0{\frac{1}{2}}^{-}$ can be used to explain the $\Lambda (1405)$, and together with another state $\Sigma \pi$ is related to the two-pole structure of the scattering amplitude proposed before. The decay properties of $\Lambda (1520)$ prevent the assignment of ${\Sigma }^{\ast }\pi$ with $I{J}^P=0{\frac{3}{2}}^{-}$ to $\Lambda (1520)$, although the energy $\sim$ 1518 MeV of ${\Sigma }^{\ast }\pi$ is close to experimental value of $\Lambda (1520)$. Other resonance states generally have a large width.

    hep-phPRC(2021)·11 citations
11. 11*

    Higgs-Portal Dark Matter in Nonlinear MSSM

    Masato Arai🇯🇵 · Nobuchika Okada🇺🇸

    Supersymmetric (SUSY) extension of the Standard Model (SM) is a primary candidate for new physics beyond the SM. If SUSY breaking scale is very low, for example, the multi-TeV range, and the SUSY breaking sector, except for the goldstino (gravitino), is decoupled from the low energy spectrum, the hidden sector effect in the minimal SUSY SM (MSSM) is well described by employing the goldstino chiral superfield ($X$) with the nilpotent condition of $X^2=0$. Although this so-called "nonlinear MSSM" (NL-MSSM) provides a variety of interesting phenomenologies, there is a cosmological problem that the lightest superpartner gravitino is too light to be the major component of the dark matter (DM) in our universe. To solve this problem, we propose a minimal extension of the NL-MSSM by introducing a parity-odd SM singlet chiral superfield ($\Phi$). We show that the interaction of the scalar component in $\Phi$ with the MSSM Higgs doublets is induced after eliminating F-component of the goldstino superfield and the lightest real scalar in $\Phi$ plays the role of the Higgs-portal DM. With a suitable choice of the model parameters, a successful Higgs-portal DM scenario can be realized while achieving the SM-like Higgs boson mass of 125 GeV from the tree-level Higgs potential through the multi-TeV SUSY breaking effect.

    hep-phPRD(2021)·1 citation
12. 12*

    pQCD running couplings finite and monotonic in the infrared: when do they reflect the holomorphic properties of spacelike observables?

    Carlos Contreras🇨🇱 · Gorazd Cvetic🇨🇱 · Oscar Orellana🇨🇱

    We investigate a large class of perturbative QCD (pQCD) renormalization schemes whose beta functions $\beta (a)$ are meromorphic functions of the running coupling and give finite positive value of the coupling $a(Q^2)$ in the infrared regime ("freezing"), $a(Q^2)\to a_0$ for $Q^2\to 0$. Such couplings automatically have no singularities on the positive axis of the squared momenta $Q^2$ ($\equiv -q^2$). Explicit integration of the renormalization group equation (RGE) leads to the implicit (inverted) solution for the coupling, of the form $\ln (Q^2/Q_{\mathrm{in}}^2)=\mathcal{H}(a)$. An analysis of this solution leads us to an algebraic algorithm for the search of the Landau singularities of $a(Q^2)$ on the first Riemann sheet of the complex $Q^2$-plane, i.e., poles and branching points (with cuts) outside the negative semiaxis. We present specific representative examples of the use of such algorithm, and compare the found Landau singularities with those seen after the 2-dimensional numerical integration of the RGE in the entire first Riemann sheet, where the latter approach is numerically demanding and may not always be precise. The specific examples suggest that the presented algebraic approach is useful to find out whether the running pQCD coupling has Landau singularities and, if yes, where precisely these singularities are.

    hep-phhep-thJ.Phys.Comm.(2021)·6 citations
13. 13*

    Color, Flavor, Temperature and Magnetic Field Dependence of QCD Phase Diagram: Magnetic Catalysis and its Inverse

    Aftab Ahmad🇵🇰 · Adnan Bashir🇲🇽 · Marco A. Bedolla🇲🇽 · J.J. Cobos-Martínez🇲🇽

    We study dynamical chiral symmetry breaking for quarks in the fundamental representation of $SU(N_c)$ for $N_f$ number of light quark flavors. We also investigate the phase diagram of quantum chromodynamics at finite temperature $T$ and/or in the presence of a constant external magnetic field $eB$. The unified formalism for this analysis is provided by a symmetry-preserving Schwinger-Dyson equations treatment of a vector$\times$vector contact interaction model which encodes several well-established features of quantum chromodynamics to mimic the latter as closely as possible. Deconfinement and chiral symmetry restoration are triggered above a critical value of $N_f$ at $T=0=eB$. On the other hand, increasing temperature itself screens strong interactions, thus ensuring that a smaller value of $N_f$ is sufficient to restore chiral symmetry at higher temperatures. We also observe the well-known phenomenon of magnetic catalysis for a strong enough magnetic field. However, we note that if the effective coupling strength of the model decreases as a function of magnetic field, it can trigger inverse magnetic catalysis in a certain window of this functional dependence. Our model allows for the simultaneous onset of dynamical chiral symmetry breaking and confinement for each case. Qualitative as well as quantitative predictions of our simple but effective model are in reasonably satisfactory agreement with lattice results and other reliable and refined predictions based upon intricate continuum studies of quantum chromodynamics.

    hep-phnucl-thJ.Phys.G(2021)·16 citations
14. 14*

    Polarization Rotation of Chiral Fermions in Vortical Fluid

    Defu Hou🇨🇳 · Shu Lin🇨🇳

    The rotation of polarization occurs for light interacting with chiral materials. It requires the light states with opposite chiralities interact differently with the materials. We demonstrate analogous rotation of polarization also exists for chiral fermions interacting with quantum electrodynamics plasma with vorticity using chiral kinetic theory. We find that the rotation of polarization is perpendicular both to vorticity and fermion momentum. The effect also exists for chiral fermions in quantum chromodynamics plasma with vorticity. It could lead to generation of a vector current when the probe fermions contain momentum anisotropy.

    hep-phcond-mat.mes-hallnucl-thPLB(2021)·18 citations
15. 15*

    A Hybrid Renormalization Scheme for Quasi Light-Front Correlations in Large-Momentum Effective Theory

    Xiangdong Ji🇺🇸 · Yizhuang Liu🇨🇳 · Andreas Schäfer🇩🇪 · Wei Wang🇨🇳 · Yi-Bo Yang🇨🇳 · Jian-Hui Zhang🇨🇳 · Yong Zhao🇺🇸

    In large-momentum effective theory (LaMET), calculating parton physics starts from calculating coordinate-space-$z$ correlation functions $\tilde{h}(z,a,P^z)$ in a hadron of momentum $P^z$ in lattice QCD. Such correlation functions involve both linear and logarithmic divergences in lattice spacing $a$, and thus need to be properly renormalized. We introduce a hybrid renormalization procedure to match these lattice correlations to those in the continuum $\overline{\mathrm{MS}}$ scheme, without introducing extra non-perturbative effects at large $z$. We analyze the effect of $\mathcal{O}({\Lambda }_{\mathrm{QCD}})$ ambiguity in the Wilson line self-energy subtraction involved in this hybrid scheme. To obtain the momentum-space distributions, we recommend to extrapolate the lattice data to the asymptotic $z$-region using the generic properties of the coordinate space correlations at moderate and large $P^z$, respectively.

    hep-phhep-exhep-latnucl-ex+1NPB(2021)·143 citations
16. 16*

    Supernova-scope for the Direct Search of Supernova Axions

    Shao-Feng Ge🇨🇳 · Koichi Hamaguchi🇯🇵 · Koichi Ichimura🇯🇵 · Koji Ishidoshiro🇯🇵 · Yoshiki Kanazawa🇯🇵 · Yasuhiro Kishimoto🇯🇵 · Natsumi Nagata🇯🇵 · Jiaming Zheng🇨🇳

    If a supernova explosion occurs within a few hundred parsecs from the Earth, a huge number of axions, in addition to neutrinos, may arrive at the Earth. In this paper, we discuss in detail the prospect of detecting those supernova axions by an axion helioscope. With the help of a pre-supernova neutrino alert system, it is possible to point a helioscope at an exploding supernova in advance. The supernova axions can then be detected by a gamma-ray detector installed at the end of the helioscope. We call such a detection system an axion supernova-scope (SNscope). We propose a conceptual design for an axion SNscope, where the gamma-ray detector is installed at the opposite end to the X-ray detector for the solar axion. It still functions as an axion helioscope during the normal operation time, and once a pre-SN neutrino alert is received, the scope is temporarily turned around and targeted to a SN candidate, waiting for the supernova axions. We estimate the sensitivity of supernova axion detection and find that SNscopes based on the next-generation axion helioscopes, such as IAXO, have potential to explore the invisible axions and to test the axion interpretation of stellar cooling anomalies.

    hep-phastro-ph.HEhep-exJCAP(2020)·34 citations
17. 17*

    Inverse moment of the $B_s$-meson distribution amplitude from QCD sum rule

    Alexander Khodjamirian🇩🇪 · Rusa Mandal🇩🇪 · Thomas Mannel🇩🇪

    We derive a QCD sum rule for the inverse moment of the $B_s$-meson light-cone distribution amplitude in HQET. Within this method, the $SU(3{)}_{fl}$ symmetry violation is traced to the strange quark mass and to the difference between strange and nonstrange quark condensate densities. We predict the ratio of inverse moments ${\lambda }_{B_s}/{\lambda }_B=1.19\pm 0.14$ which can be used in various applications of these distribution amplitudes to the analyses of $B_s$-meson decays, provided an accurate value of ${\lambda }_B$ is available from other sources, such as the $B\to \ell {\nu }_{\ell }\gamma$ decay.

    hep-phhep-exJHEP(2020)·58 citations
18. 18*

    Investigating the effect of $U_1$ vector leptoquark on $b\to u\tau \bar{\nu }$ mediated $B$ decays

    Suman Kumbhakar🇮🇳 · Rukmani Mohanta🇮🇳

    The recent measurements of lepton flavor university (LFU) violating observables in semileptonic $b\to c\ell \bar{\nu }$ and $b\to s{\ell }^{+}{\ell }^{-}$ transitions by various experiments exhibit $(2-3)\sigma$ deviations from their corresponding Standard Model (SM) predictions. These tantalizing signals hint towards the possible role of new physics (NP) in $b\to c\tau \bar{\nu }$ and $b\to s{\mu }^{+}{\mu }^{-}$ decay channels. This in turn indicates that the same class of NP as appeared in $b\to c\tau \bar{\nu }$, might also show up in other tree level processes involving $b\to u\tau \bar{\nu }$ transition. Since these charged current transitions are doubly Cabibbo suppressed, the NP contributions could be significant enough leading to sizeable effects in some of the observables. In this paper, we study the implications of the vector leptoquark $U_1(3,1,2/3)$, which is one of the few scenarios that can simultaneously explain the LFU violation signals both in the charged-current as well as neutral-current sectors, on the semileptonic decays $B\to (\pi ,\rho ,\omega )\tau \bar{\nu }$ and $B_s\to (K,K^{\ast })\tau \bar{\nu }$. In particular, we pay our attention to the branching fraction, lepton flavor non-universality (LNU) observable, forward-backward asymmetry and the polarization asymmetry parameters of these modes. We find substantial deviations in the branching fractions as well as LNU observables of these decay modes due to the $U_1$ contributions, which can be probed by the currently running experiments LHCb and Belle-II.

    hep-phhep-exJ.Phys.G(2021)·7 citations
19. 19*

    Associated Higgs boson production with $Z$ boson in the minimal $U(1{)}_X$ extended Standard Model

    Arindam Das🇯🇵 · Nobuchika Okada🇺🇸

    The minimal $U(1{)}_X$ extension of the Standard Model (SM) is a simple and well-motivated extension of the SM, which supplements the SM with the seesaw mechanism for naturally generating the light neutrino masses and offers various interesting phenomenologies. In the model, the $U(1{)}_X$ charge of each SM field is characterized by the $U(1{)}_X$ charge of the SM Higgs doublet with a free parameter $x_H$. Due to the $U(1{)}_X$ charge of the Higgs doublet, the Higgs boson has a trilinear coupling with the $Z$ boson and the $U(1{)}_X$ gauge boson ($Z^{\prime }$). With this coupling, a new process for the associated Higgs boson production with a $Z$ boson arises through a $Z^{\prime }$ boson in the $s$-channel at high energy colliders. In this paper, we calculate the associated Higgs boson production at high energy colliders and show interesting effects of the new $Z^{\prime }$ boson mediated process, which can be tested in the future.

    hep-phhep-exNPB(2023)·2 citations
20. 20*

    Non-standard neutrino interactions as a solution to the NO$\nu$A and T2K discrepancy

    Sabya Sachi Chatterjee🇬🇧 · Antonio Palazzo🇮🇹

    The latest data of the two long-baseline accelerator experiments NO$\nu$A and T2K, interpreted in the standard 3-flavor scenario, display a discrepancy. A mismatch in the determination of the standard CP-phase ${\delta }_{\mathrm{CP}}$ extracted by the two experiments is evident in the normal neutrino mass ordering. While NO$\nu$A prefers values close to ${\delta }_{\mathrm{CP}}\sim 0.8\pi$, T2K identifies values of ${\delta }_{\mathrm{CP}}\sim 1.4\pi$. Such two estimates are in disagreement at more than 90$\%$ C.L. for 2 degrees of freedom. We show that such a tension can be resolved if one hypothesizes the existence of complex neutral-current non-standard interactions (NSI) of the flavor changing type involving the $e-\mu$ or the $e-\tau$ sectors with couplings $|{\epsilon }_{e\mu }|\sim |{\epsilon }_{e\tau }|\sim 0.2$. Remarkably, in the presence of such NSI, both experiments point towards the same common value of the standard CP-phase ${\delta }_{\mathrm{CP}}\sim 3\pi /2$. Our analysis also highlights an intriguing preference for maximal CP-violation in the non-standard sector with the NSI CP-phases having best fit close to ${\varphi }_{e\mu }\sim {\varphi }_{e\tau }\sim 3\pi /2$, hence pointing towards imaginary NSI couplings.

    hep-phhep-exPRL(2021)·99 citations
21. 21*

    Leptogenesis from the Asymmetric Texture

    Moinul Hossain Rahat🇺🇸

    We investigate non-resonant thermal leptogenesis in the context of the $SU(5)\times {\mathcal{T}}_{13}$ "asymmetric texture", where both Dirac and Majorana $CP$ violation arise from a single phase in the tribimaximal seesaw mixing matrix. We show that the baryon asymmetry of the universe can be explained in this model only when flavor effects are considered for right-handed neutrino masses of $\mathcal{O}(10^9-10^{12})$ $\text{GeV}$. The sign of the baryon asymmetry also determines the sign of the previously predicted Dirac $\text{require}cancel\cancel{CP}$ phase $|{\delta }_{CP}|=1.32\pi$, consistent with the latest global fit ${\delta }_{CP}^{PDG}=1.37\pm 0.17\pi$.

    hep-phastro-ph.HEhep-thPRD(2021)·14 citations
22. 22*

    Solution to the Sudakov suppressed Balitsky-Kovchegov equation and its application to the HERA data

    Wenchang Xiang🇨🇳 · Mengliang Wang🇨🇳 · Yanbing Cai🇨🇳 · Daicui Zhou🇨🇳

    We analytically solve the Sudakov suppressed Balitsky-Kovchegov evolution equation with the fixed and running coupling constants in the saturation region. The analytic solution of the $S$-matrix shows the $\exp (\mathcal{O}({\eta }^2))$ rapidity dependence of the solution with the fixed coupling constant is replaced by $\exp (\mathcal{O}({\eta }^{3/2}))$ dependence in the smallest dipole running coupling case rather than obeying the law found in our previous publication, in which all the solutions of the next-to-leading order evolution equations comply with $\exp (\mathcal{O}(\eta ))$ rapidity dependence once the QCD coupling is switched from the fixed coupling to the smallest dipole running coupling prescription. This finding indicates that the corrections of the sub-leading double logarithms in the Sudakov suppressed evolution equation are significant, which compensate part of the evolution decrease of the dipole amplitude made by running coupling effect. To test the analytic findings, we calculate the numerical solutions of the Sudakov suppressed evolution equation, the numerical results confirm the analytic outcomes. Moreover, we use the numerical solutions of the evolution equation to fit the HERA data. It shows that the Sudakove suppressed evolution equation can give good quality fit to the data.

    hep-phCPC(2021)·6 citations
23. 23*

    Threshold pion electro- and photoproduction off nucleons in covariant chiral perturbation theory

    Gustavo H. Guerrero Navarro🇪🇸 · M. J. Vicente Vacas🇪🇸

    Pion electro- and photoproduction off the nucleon close to threshold is studied in covariant baryon chiral perturbation theory at O($p^3$) in the extended-on-mass-shell scheme, with the explicit inclusion of the $\Delta (1232)$ resonance. The relevant low energy constants are fixed by fitting the available experimental data with the theoretical model. The inclusion of the $\Delta$ resonance as an explicit degree of freedom substantially improves the agreement with data and the convergence of the model.

    hep-phPRD(2020)·16 citations
24. 24*

    Elastic Potential: A proposal to discover elastic production of top quarks at the Large Hadron Collider

    James Howarth🇬🇧

    In this letter, I present the motivation and an example analysis method for discovering the elastic production of top-quark pairs at the LHC using forward proton tags, including an overview of the current theoretical tools and experimental acceptance. I show that it is possible to discover the semi-elastic process with only 300 pb${}^{-1}$ of data but that the fully-elastic case is currently out of reach. I also illustrate how the use of forward proton tags can result in limits on the branching ratio for flavor changing neutral current decays of the top quark of the form $t\to u\gamma$ and $t\to c\gamma$ of $<0.39\cdot 10^{-5}$ and $<0.97\cdot 10^{-5}$, respectively, both of which would surpass the existing world limits by at least an order of magnitude.

    hep-phhep-ex11 citations
25. 25*

    Direct detection of dark matter: Precision predictions in a simplified model framework

    Christoph Borschensky🇩🇪 · Gabriele Coniglio🇩🇪 · Barbara Jäger🇩🇪 · Josef Jochum🇩🇪 · Vincent Schipperges🇩🇪

    We present a calculation of the next-to-leading order QCD corrections for the scattering of Dark Matter particles off nucleons in the framework of simplified models with s- and t-channel mediators. These results are matched to the Wilson coefficients and operators of an effective field theory that is generally used for the presentation of experimental results on spin-independent and spin-dependent direct detection rates. Detailed phenomenological studies illustrate the complementary reach of collider searches for Dark Matter and the direct detection experiments CRESST and XENON. In the case of cancellation effects in the tree-level contributions, one-loop corrections can have a particularly large impact on exclusion limits in the case of combined s+t-channel models.

    hep-phEPJC(2021)·8 citations
26. 26*

    Probing New Physics in Dimension-8 Neutral Gauge Couplings at $e^{+}{e}^{-}$ Colliders

    John Ellis🇬🇧 · Hong-Jian He🇨🇳 · Rui-Qing Xiao🇨🇳

    Neutral triple gauge couplings (nTGCs) are absent in the standard model effective theory up to dimension-6 operators, but could arise from dimension-8 effective operators. In this work, we study the pure gauge operators of dimension-8 that contribute to nTGCs and are independent of the dimension-8 operator involving the Higgs doublet. We show that the pure gauge operators generate both $Z\gamma Z^{\ast }$ and $Z\gamma {\gamma }^{\ast }$ vertices with rapid energy dependence $\propto E^5$, which can be probed sensitively via the reaction $e^{+}{e}^{-}\to Z\gamma$. We demonstrate that measuring the nTGCs via the reaction $e^{+}{e}^{-}\to Z\gamma$ followed by $Z\to q\bar{q}$ decays can probe the new physics scales of dimension-8 pure gauge operators up to the range $(1-5)$TeV at the CEPC, FCC-ee and ILC colliders with $\sqrt{s}=(0.25-1)$TeV, and up to the range $(10-16)$TeV at CLIC with $\sqrt{s}=(3-5)$TeV, assuming in each case an integrated luminosity of 5/ab. We compare these sensitivities with the corresponding probes of the dimension-8 nTGC operators involving Higgs doublets and the dimension-8 fermionic contact operators that contribute to the $e^{+}{e}^{-}Z\gamma$ vertex.

    hep-phhep-exSCPMA(2021)·90 citations
27. 27*

    Neutrino masses, vacuum stability and quantum gravity prediction for the mass of the top quark

    Guillem Domènech🇩🇪 · Mark Goodsell🇫🇷 · Christof Wetterich🇩🇪

    A general prediction from asymptotically safe quantum gravity is the approximate vanishing of all quartic scalar couplings at the UV fixed point beyond the Planck scale. A vanishing Higgs doublet quartic coupling near the Planck scale translates into a prediction for the ratio between the mass of the Higgs boson $M_H$ and the top quark $M_t$. If only the standard model particles contribute to the running of couplings below the Planck mass, the observed $M_H\sim 125\mathrm{GeV}$ results in the prediction for the top quark mass $M_t\sim 171\mathrm{GeV}$, in agreement with recent measurements. In this work, we study how the asymptotic safety prediction for the top quark mass is affected by possible physics at an intermediate scale. We investigate the effect of a $SU(2)$ triplet scalar and right-handed neutrinos, needed to explain the tiny mass of left-handed neutrinos. For pure seesaw II, with no or very heavy right handed neutrinos, the top mass can increase to $M_t\sim 172.5\mathrm{GeV}$ for a triplet mass of $M_{\Delta }\sim 10^8\mathrm{GeV}$. Right handed neutrino masses at an intermediate scale increase the uncertainty of the predictions of $M_t$ due to unknown Yukawa couplings of the right-handed neutrinos and a cubic interaction in the scalar potential. For an appropriate range of Yukawa couplings there is no longer an issue of vacuum stability.

    hep-phgr-qchep-thJHEP(2021)·33 citations
28. 28*

    'Deep' Dive into $b\to c$ Anomalies: Standardized and Future-proof Model Selection Using Self-normalizing Neural Networks

    Srimoy Bhattacharya🇨🇳 · Soumitra Nandi🇮🇳 · Sunando Kumar Patra🇮🇳 · Shantanu Sahoo🇮🇳

    Noting the erroneous proclivity of information-theoretic approaches, like the Akaike information criterion (AIC), to select simpler models while performing model selection with a small sample size, we address the problem of new physics model selection in $b\to c\tau {\nu }_{\tau }$ decays in this paper by employing a specific machine learning algorithm (self-normalizing neural networks, a.k.a. SNN) for supervised classification and regression, in a model-independent framework. While the outcomes of the classification with real data-set are compared with AIC, with the SNNs outperforming AIC${}_c$ in all aspects of model selection, the regression-outcomes are compared with the results from Bayesian analyses; the obtained parameter spaces differ considerably while keeping maximum posterior (MAP) estimates similar. A few of the two-operator scenarios with a tensor-type interaction are found to be the most probable solution for the data. We also test the effectiveness of our trained networks with the expected, more precise data in Belle-II. The trained networks and associated functionalities are supplied for the use of the community.

    hep-phhep-exhep-latphysics.data-an3 citations
29. 29*

    Measuring the polarization of boosted, hadronic $W$ bosons with jet substructure observables

    Songshaptak De🇮🇳 · Vikram Rentala🇮🇳 · William Shepherd🇺🇸

    In this work, we present a new technique to measure the longitudinal and transverse polarization fractions of hadronic decays of boosted $W$ bosons. We introduce a new jet substructure observable denoted as $p_{\theta }$, which is a proxy constructed purely out of subjet energies for the parton level decay polar angle of the $W$ boson in its rest-frame. The distribution of this observable is sensitive to the polarization of $W$ bosons and can therefore be used to reconstruct the $W$ polarization in a way that is independent of the production process -- assuming Standard Model (SM) rules governing decays. We argue that this proxy variable has lower reconstruction errors as compared to the other proxies that have been used by the experimental collaborations, especially for large boosts of the $W$-boson. As a test case, we study the efficacy of our technique on vector boson scattering (VBS) processes at the high luminosity Large Hadron Collider. We find that with only SM production channels, measuring the longitudinal polarization fraction is likely to be challenging even with 10 ab${}^{-1}$ of data. We suggest further strategies and scenarios that may improve the prospects of measurement of the hadronic $W$ polarization fraction.

    hep-phhep-exJHEP(2025)·21 citations
30. 30*

    The Mysterious Bursts observed by Telescope Array and Axion Quark Nuggets

    Ariel Zhitnitsky🇨🇦

    Telescope Array (TA) experiment has recorded \cite{Abbasi:2017rvx,Okuda_2019} several short time bursts of air shower like events. These bursts are very distinct from conventional single showers, and are found to be strongly correlated with lightnings. We propose that these bursts represent the direct manifestation of the dark matter annihilation events within the so-called axion quark nugget (AQN) model, which was originally invented for completely different purpose to explain the observed similarity between the dark and the visible components in the Universe, i.e. ${\Omega }_{\mathrm{DM}}\sim {\Omega }_{\mathrm{visible}}$ without any fitting parameters. We support this proposal by demonstrating that the observations \cite{Abbasi:2017rvx,Okuda_2019}, including the frequency of appearance, temporal and spatial distributions, intensity, and other related observables are nicely match the emission features of the AQNs propagating in the atmosphere under thunderstorm. We propose to test these ideas by reanalyzing the existing data by increasing the cutoff time scale $\Delta t=1$ ms for the bursts. We also suggest to test this proposal by analyzing the correlations with proper infrasound and seismic instruments. We also suggest to search for the radio signal with frequency $\nu \in (3-300)$ MHz which must be synchronized with bursts.

    hep-phastro-ph.EPastro-ph.HEphysics.ao-phJ.Phys.G(2021)·18 citations
31. 31*

    Curvature Invariants for the Accelerating Natario Warp Drive

    B. Mattingly🇺🇸 · A. Kar🇺🇸 · M. Gorban🇺🇸 · W. Julius🇺🇸 · C. K. Watson🇺🇸 · M. D. Ali🇺🇸 · A. Baas🇺🇸 · C. Elmore🇺🇸 · J. S. Lee🇺🇸 · B. Shakerin🇺🇸 · E. W. Davis🇺🇸 · G. B. Cleaver🇺🇸

    A process for using curvature invariants is applied to evaluate the accelerating Natario warp drive. Curvature invariants are independent of coordinate bases and plotting the invariants is free of coordinate mapping distortions. While previous works focus mainly on the mathematical description of the warp bubble, plotting curvature invariants provides a novel pathway to investigate the Natário spacetime and its characteristics. For warp drive spacetimes, there are four independent curvature invariants the Ricci scalar, r_1, r_2, and w_2. The invariant plots demonstrate how each curvature invariant evolves over the parameters of time, acceleration, skin depth and radius of the warp bubble. They show that the Ricci scalar has the greatest impact of the invariants on the surrounding spacetime. They also reveal key features of the Natario warp bubble such as a flat harbor in the center of it, a dynamic wake, and the internal structures of the warp bubble.

    ↳ gr-qchep-phhep-thParticles(2020)·10 citations
32. 32*

    Polyatomic Molecules as Quantum Sensors for Fundamental Physics

    Nicholas R. Hutzler🇺🇸

    Precision measurements in molecules have advanced rapidly in recent years through developments in techniques to cool, trap, and control. The complexity of molecules makes them a challenge to study, but also offers opportunities for enhanced sensitivity to many interesting effects. Polyatomic molecules offer additional complexity compared to diatomic molecules, yet are still "simple" enough to be laser-cooled and controlled. While laser cooling molecules is still a research frontier itself, there are many proposed and ongoing experiments seeking to combine the advanced control enabled by ultracold temperatures with the intrinsic sensitivity of molecules. In this perspective, we discuss some applications where laser-cooled polyatomic molecules may offer advantages for precision measurements of fundamental physics, both within and beyond the Standard Model.

    ↳ physics.atom-phhep-phphysics.chem-phQuantum Sci.Technol.(2020)·101 citations
33. 33*

    Geometric Quantum Information Structure in Quantum Fields and their Lattice Simulation

    Natalie Klco🇺🇸 · Martin J. Savage🇺🇸

    An upper limit to distillable entanglement between two disconnected regions of massless non-interacting scalar field theory has an exponential decay defined by a geometric decay constant. When regulated at short distances with a spatial lattice, this entanglement abruptly vanishes beyond a dimensionless separation, defining a negativity sphere. In two spatial dimensions, we determine this geometric decay constant between a pair of disks and the growth of the negativity sphere toward the continuum through a series of lattice calculations. Making the connection to quantum field theories in three-spatial dimensions, assuming such quantum information scales appear also in quantum chromodynamics (QCD), a new relative scale may be present in effective field theories describing the low-energy dynamics of nucleons and nuclei. We highlight potential impacts of the distillable entanglement structure on effective field theories, lattice QCD calculations and future quantum simulations.

    ↳ quant-phhep-lathep-phnucl-thPRD(2021)·35 citations
34. 34*

    From Ji to Jaffe-Manohar orbital angular momentum in Lattice QCD using a direct derivative method

    M. Engelhardt🇺🇸 · J. R. Green🇨🇭 · N. Hasan🇩🇪 · S. Krieg🇩🇪 · S. Meinel🇺🇸 · J. Negele🇺🇸 · A. Pochinsky🇺🇸 · S. Syritsyn🇺🇸

    A Lattice QCD approach to quark orbital angular momentum in the proton based on generalized transverse momentum-dependent parton distributions (GTMDs) is enhanced methodologically by incorporating a direct derivative technique. This improvement removes a significant numerical bias that had been seen to afflict results of a previous study. In particular, the value obtained for Ji quark orbital angular momentum is reconciled with the one obtained independently via Ji's sum rule, validating the GMTD approach. Since GTMDs simultaneously contain information about the quark impact parameter and transverse momentum, they permit a direct evaluation of the cross product of the latter. They are defined through proton matrix elements of a quark bilocal operator containing a Wilson line; the choice in Wilson line path allows one to continuously interpolate from Ji to Jaffe-Manohar quark orbital angular momentum. The latter is seen to be significantly enhanced in magnitude compared to Ji quark orbital angular momentum, confirming previous results.

    ↳ hep-lathep-phnucl-thPRD(2020)·26 citations
35. 35*

    Hadronic effects on charmonium elliptic flows in heavy-ion collisions

    Baoyi Chen🇨🇳 · Liu Jiang🇺🇸 · Yunpeng Liu🇨🇳

    Transport and Langevin equations are employed to study hadronic medium effects on charmonium elliptic flows in heavy-ion collisions. In Pb-Pb collisions, the anisotropic energy density of the quark-gluon plasma (QGP) in the transverse plane is transformed into hadron momentum anisotropy after the phase transition. Charmonia with high transverse momentum $p_T$ are produced via the primordial hard process and undergo different degrees of dissociation along different paths in the QGP. They then scatter with light hadrons in the hadron phase. Both contributions to the charmonium elliptic flows are studied at moderate and high transverse momenta. The elliptic flows of the prompt $J/\psi$ are found to be considerably enhanced at high transverse momentum when the charmonium diffusion coefficients in the hadronic medium are parametrized through the geometry scale approximation. This hadronic medium effect is negligible for quarkonia with larger mass such as bottomonia.

    ↳ nucl-thhep-phPRC(2021)·1 citation
36. 36*

    On the application of Effective Field Theory to finite-volume effects in $a_{\mu }^{\mathrm{HVP}}$

    Christopher Aubin🇺🇸 · Thomas Blum🇺🇸 · Maarten Golterman🇺🇸 · Santiago Peris🇪🇸

    One of the more important systematic effects affecting lattice computations of the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon, $a_{\mu }^{\mathrm{HVP}}$, is the distortion due to a finite spatial volume. In order to reach sub-percent precision, these effects need to be reliably estimated and corrected for, and one of the methods that has been employed for doing this is finite-volume chiral perturbation theory. In this paper, we argue that finite-volume corrections to $a_{\mu }^{\mathrm{HVP}}$ can, in principle, be calculated at any given order in chiral perturbation theory. More precisely, once all low-energy constants needed to define the Effective Field Theory representation of $a_{\mu }^{\mathrm{HVP}}$ in infinite volume are known to a given order, also the finite-volume corrections can be predicted to that order in the chiral expansion.

    ↳ hep-lathep-phPRD(2020)·24 citations
37. 37*

    Dynamical spectral structure of density fluctuation near QCD critical point

    Md Hasanujjaman🇮🇳 · Golam Sarwar🇮🇳 · Mahfuzur Rahaman🇮🇳 · Abhijit Bhattacharyya🇮🇳 · Jan-e Alam🇮🇳

    The expression for the dynamical spectral structure of the density fluctuation near the QCD critical point has been derived using linear response theory within the purview of Israel-Stewart relativistic viscous hydrodynamics. The change in spectral structure of the system as it moves toward critical end point has been studied. The effects of the critical point have been introduced in the system through a realistic equation of state and the scaling behaviour of various transport coefficients and thermodynamic response functions. We have found that the Brillouin and the Rayleigh peaks are distinctly visible when the system is away from critical point but the peaks tend to merge near the critical point. The sensitivity of structure of the spectral function on wave vector ($k$) of the sound wave has been demonstrated. It has been shown that the Brillouin peaks get merged with the Rayleigh peak because of the absorption of sound waves in the vicinity of the critical point.

    ↳ nucl-thhep-exhep-phEPJA(2021)·8 citations
38. 38*

    Gauss-Bonnet inflation with a constant rate of roll

    Tie-Jun Gao🇨🇳

    We consider the constant-roll condition in the model of the inflaton nonminimal coupling to the Gauss-Bonnet term. By assuming the first Gauss-Bonnet flow parameter ${\delta }_1$ is a constant, we discuss the constant-roll inflation with constant ${ϵ}_1$, constant ${ϵ}_2$ and constant ${\eta }_H$, respectively. Using the Bessel function approximation, we get the analytical expressions for the scalar and tensor power spectrum and derive the scalar spectral index $n_{\mathcal{R}}$ and the tensor to scalar ratio $r$ to the first order of ${ϵ}_1$. By using the Planck 2018 observations constraint on $n_{\mathcal{R}}$ and $r$, we obtain some feasible parameter space and show the result on the $n_{\mathcal{R}}-r$ region. The scalar potential is also reconstructed in some spectral cases.

    ↳ gr-qchep-phEPJC(2020)·12 citations
39. 39*

    RG flows in Non-Perturbative Gauge-Higgs Unification II. Effective action for the Higgs phase near the quantum phase transition

    Nikos Irges🇬🇷 · Fotis Koutroulis🇬🇷

    We construct the zero temperature (no compact dimensions) effective action for an SU(2) Yang-Mills theory in five dimensions, with boundary conditions that reduce the symmetry on the four-dimensional boundary located at the origin to a U(1)-complex scalar system. In order to be sensitive to the Higgs phase, we need to include higher dimensional operators in the effective action, which can be naturally achieved by generating it by expanding the corresponding lattice construction in small lattice spacing, taking the naive continuum limit and then renormalizing. In addition, we build in the effective action non-perturbative information, related to a first order quantum phase transition known to exist. As a result, the effective action acquires a finite cut-off that is low and the fine tuning of the scalar mass is rather mild.

    ↳ hep-thhep-phEPJC(2021)·5 citations
40. 40*

    Effective field theory for non-relativistic hydrodynamics

    Akash Jain🇨🇦

    We write down a Schwinger-Keldysh effective field theory for non-relativistic (Galilean) hydrodynamics. We use the null background construction to covariantly couple Galilean field theories to a set of background sources. In this language, Galilean hydrodynamics gets recast as relativistic hydrodynamics formulated on a one-dimension higher spacetime admitting a null Killing vector. This allows us to import the existing field-theoretic techniques for relativistic hydrodynamics into the Galilean setting, with minor modifications to include the additional background vector field. We use this formulation to work out an interacting field theory describing stochastic fluctuations of energy, momentum, and density modes around thermal equilibrium. We also present a translation of our results to the more conventional Newton-Cartan language and discuss how the same can be derived via a non-relativistic limit of the effective field theory for relativistic hydrodynamics.

    ↳ hep-thcond-mat.stat-mechhep-phmath-ph+2JHEP(2020)·28 citations
41. 41*

    Quartic cumulant of baryon number in the presence of QCD critical point

    D. Mroczek🇺🇸 · J. Noronha-Hostler🇺🇸 · A. R. Nava Acuna🇺🇸 · C. Ratti🇺🇸 · P. Parotto🇩🇪 · M.A. Stephanov🇺🇸

    In the context of the ongoing search for the QCD critical point at the Relativistic Heavy-Ion Collider, we study the equation of state near the critical point in the temperature and baryon chemical potential plane. We use the parametric representation introduced in earlier literature, which maps the universal 3D Ising equation of state onto the QCD phase diagram using several non-universal parameters. We focus on the quartic cumulant of the baryon number, or baryon number susceptibility~${\chi }_4^B$, which can be accessed experimentally via net-proton fluctuation kurtosis measurements. It was originally predicted, through universality arguments based on the {\em leading} singular contribution, that ${\chi }_4^B$ and net-proton kurtosis should show a specific non-monotonic behavior due to the critical point. In particular, when following the freeze-out curve on the phase diagram by decreasing beam energy, the kurtosis is expected to dip, and then peak, when the beam energy scan passes close to the critical point. We study the effects of the non-universal and thus far unknown parameters of the Ising-to-QCD mapping on the behavior of~${\chi }_4^B$. We find that, while the peak remains a solid feature, the presence of the critical point does not necessarily cause a dip in ${\chi }_4^B$ on the freezeout line {\em below} the transition temperature. The critical point contribution to the dip appears only for a narrow set of mapping parameters, when subleading singular terms are sufficiently suppressed.

    ↳ nucl-thhep-phnucl-exPRC(2021)·53 citations
42. 42*

    Cannibal domination and the matter power spectrum

    Adrienne L. Erickcek🇺🇸 · Pranjal Ralegankar🇺🇸 · Jessie Shelton🇺🇸

    Decoupled hidden sectors can easily and generically result in a period of cannibal domination, during which the dominant component of the Universe has an equation of state intermediate between radiation and matter due to self-heating by number-changing interactions. We present for the first time the consequences of a cannibal-dominated era prior to big bang nucleosynthesis for structure formation on small scales. We find that an early cannibal-dominated era imprints a characteristic peak on the dark matter power spectrum, with scale and amplitude directly determined by the mass, lifetime, and number-changing interaction strength of the cannibal field. This enhancement to the small-scale matter power spectrum will generate early-forming dark matter microhalos, and we provide a detailed and transparent map between the properties of the cannibal species and the characteristic mass and formation time of these structures. These relations demonstrate how the internal workings of a hidden sector leave a potentially observable imprint on the matter power spectrum even if dark matter has no direct couplings to the Standard Model.

    ↳ astro-ph.COhep-phPRD(2021)·46 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.