Thu·Feb 11, 2021Thursday·February 11, 2021

1. 01*

   Dirac Neutrino Mass Matrix and its Link to Freeze-in Dark Matter

   Ernest Ma (UC Riverside)🇺🇸

   Using a mechanism which allows naturally small Dirac neutrino masses and its linkage to a dark gauge $U(1{)}_D$ symmetry, a realistic Dirac neutrino mass matrix is derived from $S_3$. The dark sector naturally contains a fermion singlet having a small seesaw mass. It is thus a good candidate for freeze-in dark matter from the decay of the $U(1{)}_D$ Higgs boson.

   hep-phPLB(2021)·9 citations
2. 02*

   A $W^{\pm }$ polarization analyzer from Deep Neural Networks

   Taegyun Kim🇺🇸 · Adam Martin🇺🇸

   In this paper, we train a Convolutional Neural Network to classify longitudinally and transversely polarized hadronic $W^{\pm }$ using the images of boosted $W^{\pm }$ jets as input. The images capture angular and energy information from the jet constituents that is faithful to properties of the original quark/anti-quark $W^{\pm }$ decay products without the need for invasive substructure cuts. We find that the difference between the polarizations is too subtle for the network to be used as an event-by-event tagger. However, given an ensemble of $W^{\pm }$ events with unknown polarization, the average network output from that ensemble can be used to extract the longitudinal fraction $f_L$. We test the network on Standard Model $pp\to W^{\pm }Z$ events and on $pp\to W^{\pm }Z$ in the presence of dimension-6 operators that perturb the polarization composition.

   hep-ph21 citations
3. 03*

   Collective neutrino oscillations accounting for neutrino quantum decoherence

   Konstantin Stankevich🇷🇺 · Alexander Studenikin🇷🇺

   In our previous studies (see [1] and references therein) we developed a new theoretical framework that enabled one to consider a new mechanism of neutrino quantum decoherence engendered by the neutrino radiative decay. In parallel, another framework was developed (see [2] and references therein) for the description of the neutrino quantum decoherence due to the non-forward neutrino scattering processes. Both mechanisms are described by the master equations in the Lindblad form. We study the influence of the neutrino quantum decoherence on collective neutrino oscillations. In the present studies we are are not interested in a specific mechanism of neutrino quantum decoherence. Therefore, we use the general Lindblad master equation for the description of the neutrino quantum decoherence and do not fix an analytical expressions for the decoherence and relaxation parameters.

   hep-phPoS(2021)·5 citations
4. 04*

   ${\eta }^{(\prime )}$-meson twist-2 distribution amplitude within QCD sum rule approach and its application to the semi-leptonic decay $D_s^{+}\to {\eta }^{(\prime )}{\ell }^{+}{\nu }_{\ell }$

   Dan-Dan Hu🇨🇳 · Hai-Bing Fu🇨🇳 · Tao Zhong🇨🇳 · Long Zeng🇨🇳 · Wei Cheng🇨🇳 · Xing-Gang Wu🇨🇳

   In this paper, we make a detailed discussion on the $\eta$ and ${\eta }^{\prime }$-meson leading-twist light-cone distribution amplitude ${\varphi }_{2;{\eta }^{(\prime )}}(u,\mu )$ by using QCD sum rules approach under the background field theory. Taking both the non-perturbative condensates up to dimension-six and NLO QCD corrections to the perturbative part, its first three moments $⟨{\xi }_{2;{\eta }^{(\prime )}}^n⟩{|}_{{\mu }_0}$ with $n=(2,4,6)$ at initial scale ${\mu }_0=1$ GeV can be determined. e.g. $⟨{\xi }_{2;\eta }^2⟩{|}_{{\mu }_0}=0.231_{-0.013}^{+0.010}$, $⟨{\xi }_{2;\eta }^4⟩{|}_{{\mu }_0}=0.109_{-0.007}^{+0.007}$, and $⟨{\xi }_{2;\eta }^6⟩{|}_{{\mu }_0}=0.066_{-0.006}^{+0.006}$ for $\eta$-meson, $⟨{\xi }_{2;{\eta }^{\prime }}^2⟩{|}_{{\mu }_0}=0.211_{-0.017}^{+0.015}$, $⟨{\xi }_{2;{\eta }^{\prime }}^4⟩{|}_{{\mu }_0}=0.093_{-0.009}^{+0.009}$, and $⟨{\xi }_{2;{\eta }^{\prime }}^6⟩{|}_{{\mu }_0}=0.054_{-0.008}^{+0.008}$ for ${\eta }^{\prime }$-meson. Next, we calculate $D_s\to {\eta }^{(\prime )}$ TFFs $f_{+}^{{\eta }^{(\prime )}}(q^2)$ within QCD light-cone sum rules approach up to NLO level. The values at large recoil region are $f_{+}^{\eta }(0)=0.476_{-0.036}^{+0.040}$ and $f_{+}^{{\eta }^{\prime }}(0)=0.544_{-0.042}^{+0.046}$. After extrapolating TFFs to the allowable physical regions within the series expansion, we obtain the branching fractions of the semi-leptonic decay, i.e. $D_s^{+}\to {\eta }^{(\prime )}{\ell }^{+}{\nu }_{\ell }$, i.e. $\mathcal{B}(D_s^{+}\to {\eta }^{(\prime )}{e}^{+}{\nu }_e)=2.346_{-0.331}^{+0.418}(0.792_{-0.118}^{+0.141})\times 10^{-2}$ and $\mathcal{B}(D_s^{+}\to {\eta }^{(\prime )}{\mu }^{+}{\nu }_{\mu })=2.320_{-0.327}^{+0.413}(0.773_{-0.115}^{+0.138})\times 10^{-2}$ for $\ell =(e,\mu )$ channels respectively. And in addition to that, the mixing angle for $\eta -{\eta }^{\prime }$ with $\phi$ and ratio for the different decay channels ${\mathcal{R}}_{{\eta }^{\prime }/\eta }^{\ell }$ are given, which show good agreement with the recent BESIII measurements.

   hep-phEPJC(2022)·28 citations
5. 05*

   Detecting scale anomaly in chiral phase transition of QCD: new critical endpoint pinned down

   Mamiya Kawaguchi🇨🇳 · Shinya Matsuzaki🇨🇳 · Akio Tomiya🇺🇸

   Violation of scale symmetry, scale anomaly, being a radical concept in quantum field theory, is of importance to comprehend the vacuum structure of QCD, and should potentially contribute to the chiral phase transition in thermal QCD, as well as the chiral and U(1) axial symmetry. Though it should be essential, direct evidence of scale anomalies has never been observed in the chiral phase transition. We propose a methodology to detect a scale anomaly in the chiral phase transition, which is an electromagnetically induced scale anomaly: apply a weak magnetic field background onto two-flavor massless QCD with an extremely heavy strange quark, first observe the chiral crossover; second, adjusting the strange quark mass to be smaller and smaller, observe the second-order chiral phase transition, and then the first-order one in the massless-three flavor limit. Thus, the second-order chiral phase transition, observed as the evidence of the quantum scale anomaly, is a new critical endpoint. It turns out that this electromagnetic scale anomaly gets most operative in the weak magnetic field regime, rather than a strong field region. We also briefly address accessibility of lattice QCD, a prospected application to dense matter system, and implications to astrophysical observations, such as gravitational wave productions provided from thermomagnetic QCD-like theories.

   hep-phhep-lathep-thnucl-thJHEP(2021)·7 citations
6. 06*

   Singlino-dominated dark matter in $Z_3$-NMSSM

   Haijing Zhou🇨🇳 · Junjie Cao🇨🇳 · Jingwei Lian🇨🇳 · Di Zhang🇨🇳

   Singlino-dominated dark matter properties are investigated in the $Z_3$ Next-to-Minimal Supersymmetric Standard Model, producing superweak interactions with nucleons involved in dark matter direct detection experiments. Approximate analytical formulas describing the dark matter abundance and cross section in the scattering with nucleons are used to illustrate a dependence on theoretical parameters in neutralino and Higgs sectors. It is shown that the measured abundance requires a sizable singlet--doublet Higgs coupling parameter $\lambda$, while the experimental detection results prefer a small $\lambda$. The parameter space is then surveyed using a nest sampling technique guided by a likelihood function containing various observables in dark matter, Higgs, and B physics, such as the abundance and the scattering cross section. It is demonstrated that dark matter can achieve the correct abundance through ${\tilde{\chi }}_1^0{\tilde{\chi }}_1^0\to t\bar{t}$ or co-annihilation with higgsinos. The former process provides significantly larger Bayesian evidence than the latter, but this will be examined by the near-future PandaX-4T experiment. If the experiment shows no signs of dark matter, it will become highly disfavored. Furthermore, four cases are summarized to suppress dark matter scattering with nucleons, namely, a small $\lambda$ and three kinds of cancellation between different contributions.

   hep-phPRD(2021)·24 citations
7. 07*

   Singlino-dominated dark matter in general NMSSM

   Junjie Cao🇨🇳 · Demin Li🇨🇳 · Jingwei Lian🇨🇳 · Yuanfang Yue🇨🇳 · Haijing Zhou🇨🇳

   The general Next-to-Minimal Supersymmetric Standard Model (NMSSM) describes the singlino-dominated dark-matter (DM) property by four independent parameters: singlet-doublet Higgs coupling coefficient $\lambda$, Higgsino mass ${\mu }_{tot}$, DM mass $m_{{\tilde{\chi }}_1^0}$, and singlet Higgs self-coupling coefficient $\kappa$. The first three parameters strongly influence the DM-nucleon scattering rate, while $\kappa$ usually affects the scattering only slightly. This characteristic implies that singlet-dominated particles may form a secluded DM sector. Under such a theoretical structure, the DM achieves the correct abundance by annihilating into a pair of singlet-dominated Higgs bosons by adjusting $\kappa$'s value. Its scattering with nucleons is suppressed when $\lambda v/{\mu }_{tot}$ is small. This speculation is verified by sophisticated scanning of the theory's parameter space with various experiment constraints considered. In addition, the Bayesian evidence of the general NMSSM and that of $Z_3$-NMSSM is computed. It is found that, at the cost of introducing one additional parameter, the former is approximately $3.3\times 10^3$ times the latter. This result corresponds to Jeffrey's scale of 8.05 and implies that the considered experiments strongly prefer the general NMSSM to the $Z_3$-NMSSM.

   hep-phJHEP(2021)·24 citations
8. 08*

   Can the nature of $a_0(980)$ be tested in the $D_s^{+}\to {\pi }^{+}{\pi }^0\eta$ decay?

   Xi-Zhe Ling🇨🇳 · Ming-Zhu Liu🇨🇳 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳 · Ju-Jun Xie🇨🇳

   From the amplitude analysis of the $D_s^{+}\to {\pi }^{+}{\pi }^0\eta$ decay, the BESIII Collaboration firstly observed the $D_s^{+}\to a_0(980{)}^{+}{\pi }^0$ and $D_s^{+}\to a_0(980{)}^0{\pi }^{+}$ decay modes, which are expected to occur through the pure $W$-annihilation processes. The measured branching fraction $\mathcal{B}[D_s^{+}\to a_0(980{)}^{+(0)}{\pi }^{0(+)},a_0(980{)}^{+(0)}\to {\pi }^{+(0)}\eta ]$ is, however, found to be larger than those of known $W$-annihilation decays by one order of magnitude. This apparent contradiction can be reconciled if the two decays are induced by internal $W$-conversion or external $W$-emission mechanisms instead of $W$-annihilation mechanism. In this work, we propose that the $D_s^{+}$ decay proceeds via both the external and internal $W$-emission instead of $W$-annihilation mechanisms. In such a scenario, we perform a study of the $D_s^{+}\to {\pi }^{+}{\pi }^0\eta$ decay by taking into account the contributions from the tree diagram $D_s^{+}\to {\rho }^{+}\eta \to {\pi }^{+}{\pi }^0\eta$ and the intermediate ${\rho }^{+}\eta$ and $K^{\ast }\bar{K}/K{\bar{K}}^{\ast }$ triangle diagrams. The intermediate $a_0(980)$ state can be dynamically generated from the final state interactions of coupled $K\bar{K}$ and $\pi \eta$ channels, and it is shown that the experimental data can be described fairly well, which supports the interpretation of $a_0(980)$ as a molecular state.

   hep-phhep-exnucl-exnucl-thPRD(2021)·37 citations
9. 09*

   Assignments of the $Y(2040)$, $\rho (1900)$, and $\rho (2150)$ in the quark model

   Zheng-Ya Li🇨🇳 · De-Min Li🇨🇳 · En Wang🇨🇳 · Wen-Cheng Yan🇨🇳 · Qin-Tao Song🇨🇳

   Recently, the BESIII Collaboration reported a resonance $Y(2040)$ with $M=2034\pm 13\pm 9$ MeV and $\Gamma =234\pm 30\pm 25$ MeV in the process of $e^{+}{e}^{-}\to \omega {\pi }^0$. In addition, new measurements with much higher precision for the $\rho (1900)$ and $\rho (2150)$ states are obtained by the BESIII and BABAR Collaborations. In this work, we perform a systematic study on the mass spectrum of the excited $\rho$ resonances using the modified Godfrey-Isgur model, and the strong decays of $Y(2040)$, $\rho (1900)$, and $\rho (2150)$ within the ${}^3{P}_0$ model.We find that $Y(2040)$, $\rho (1900)$, and $\rho (2150)$ can be interpreted as the $\rho (2^3{D}_1)$, $\rho (3^3{S}_1)$, and $\rho (4^3{S}_1)$ states, respectively. Meanwhile, the mass and strong decays of the $\rho (3^3{D}_1)$ state are predicted as well, which could be helpful to search for this state in future.

   hep-phPRD(2021)·16 citations
10. 10*

    Role of $B_c^{+}\to B_{s,d}^{(\ast )}\bar{\ell }{\nu }_{\ell }$ in the Standard Model and in the search for BSM signals

    P. Colangelo🇮🇹 · F. De Fazio🇮🇹 · F. Loparco🇮🇹

    The decays $B_c^{+}\to B_a\bar{\ell }{\nu }_{\ell }$ and $B_c^{+}\to B_a^{\ast }(\to B_a\gamma )\bar{\ell }{\nu }_{\ell }$, with $a=s,d$ and $\ell =e,\mu$, are studied in the Standard Model (SM) and in the extension based on the low-energy Hamiltonian comprising the full set of dimension-$6$ semileptonic $c\to s,d$ operators with left-handed neutrinos. Tests of $\mu /e$ universality are investigated using such modes. The heavy quark spin symmetry is applied to relate the relevant hadronic matrix elements and to exploit lattice QCD results on $B_c$ form factors. Optimized observables are selected, and the pattern of their correlations is studied to identify the effects of the various operators in the extended low-energy Hamiltonian.

    hep-phhep-exhep-latPRD(2021)·26 citations
11. 11*

    Axion Quasiparticles for Axion Dark Matter Detection

    Jan Schütte-Engel🇺🇸 · David J. E. Marsh🇩🇪 · Alexander J. Millar🇸🇪 · Akihiko Sekine🇯🇵 · Francesca Chadha-Day🇬🇧 · Sebastian Hoof🇩🇪 · Mazhar Ali🇩🇪 · Kin-Chung Fong🇺🇸 · Edward Hardy🇬🇧 · Libor Šmejkal🇩🇪

    It has been suggested that certain antiferromagnetic topological insulators contain axion quasiparticles (AQs), and that such materials could be used to detect axion dark matter (DM). The AQ is a longitudinal antiferromagnetic spin fluctuation coupled to the electromagnetic Chern-Simons term, which, in the presence of an applied magnetic field, leads to mass mixing between the AQ and the electric field. The electromagnetic boundary conditions and transmission and reflection coefficients are computed. A model for including losses into this system is presented, and the resulting linewidth is computed. It is shown how transmission spectroscopy can be used to measure the resonant frequencies and damping coefficients of the material, and demonstrate conclusively the existence of the AQ. The dispersion relation and boundary conditions permit resonant conversion of axion DM into THz photons in a material volume that is independent of the resonant frequency, which is tuneable via an applied magnetic field. A parameter study for axion DM detection is performed, computing boost amplitudes and bandwidths using realistic material properties including loss. The proposal could allow for detection of axion DM in the mass range between 1 and 10 meV using current and near future technology.

    hep-phcond-mat.mes-hallcond-mat.mtrl-scicond-mat.str-elJCAP(2021)·124 citations
12. 12*

    On Stability of Fermionic Superconducting Current in Cosmic String

    Masahiro Ibe🇯🇵 · Shin Kobayashi🇯🇵 · Yuhei Nakayama🇯🇵 · Satoshi Shirai🇯🇵

    Recently, the chiral superconductivity of the cosmic string in the axion model has gathered attention. The superconductive nature can alter the standard understanding of the cosmology of the axion model. For example, a string loop with a sizable superconducting current can become a stable configuration, which is called a Vorton. The superconductive nature can also affect the cosmological evolution of the string network. In this paper, we study the stability of the superconducting current in the string. We find the superconductivity is indeed stable for a straight string or infinitely small string core size, even if the carrier particles are unstable in the vacuum. However we also find that the carrier particle decays in a curved string in typical axion models, if the carrier particles are unstable in the vacuum. Accordingly, the lifetime of the Vorton is not far from that of the carrier particle in the vacuum.

    hep-phhep-thJHEP(2021)·19 citations
13. 13*

    Electromagnetic neutrino properties: new constraints and new effects

    Alexander Studenikin🇷🇺

    The electromagnetic properties of neutrinos have attracted considerable attention from researchers for many decades (see [1] for a review). However, until recently, there was no indication in favour of nonzero electromagnetic properties of neutrinos either from laboratory experiments with ground-based neutrino sources or from observations of astrophysical neutrino fluxes. The situation changed after the XENON collaboration reported [2] results of the search for new physics with low-energy electronic recoil data recorded with the XENON1T detector. The results show an excess of events over the known backgrounds in the recoil energy which, as one of the possible explanations, admit the presence of a sizable neutrino magnetic moment, the value of which is of the order of the existing laboratory limitations. In these short notes we give a brief introduction to neutrino electromagnetic properties and focus on the most important constraints on neutrino magnetic moments, charge radii and millicharges from the terrestrial experiments and astrophysical considerations. The promising new possibilities for constraining neutrino electromagnetic properties in future experiments are also discussed.

    hep-phPoS(2021)·7 citations
14. 14*

    Bottom-induced contributions to Higgs plus jet at next-to-next-to-leading order

    Roberto Mondini🇺🇸 · Ciaran Williams🇺🇸

    We present a next-to-next-to-leading order (NNLO) QCD calculation of the bottom-induced contributions to the production of a Higgs boson plus a jet, i.e. the process $pp\to H+j$ to $\mathcal{O}(y_b^2{\alpha }_s^3)$. We work in the five-flavor scheme (5FS) in which the bottom quark mass is retained only in the coupling to the Higgs boson. Our calculation uses $N$-jettiness slicing to regulate infrared divergences, allowing for fully-differential predictions for collider observables. After extensively validating the methodology, we present results for the 13 TeV LHC. Our NNLO predictions show a marked improvement in the overall renormalization and factorization scale dependence, the latter of which proves to be particularly troublesome for 5FS calculations at lower orders. In addition, using the same methodology we present a NNLO computation of $b\overline{b}\to H$. Our results are implemented into MCFM.

    hep-phJHEP(2021)·23 citations
15. 15*

    Analysis of the kinematic boundaries of the quasi-elastic neutrino-nucleus cross section in the superscaling model with a relativistic effective mass

    I. Ruiz Simo🇪🇸 · I.D. Kakorin🇷🇺 · V.A. Naumov🇷🇺 · K.S. Kuzmin🇷🇺 · J.E. Amaro🇪🇸

    In this work we obtain the analytical expressions for the boundaries of the charged current quasi-elastic double differential cross section in terms of dimensionless energy and momentum transfers, for the Relativistic Fermi Gas (RFG) and the Super-Scaling approach with relativistic effective mass (SuSAM*) models, within the scaling formalism. In addition, we show that this double differential cross section in the scaling formalism has very good properties to be implemented in the Monte Carlo (MC) neutrino event generators, particularly because its peak is almost flat with the (anti)neutrino energy. This makes it especially well-suited for the event generation by the acceptance-rejection method usually used in the neutrino generators. Finally, we analyze the total charged current quasi-elastic (CCQE) cross section $\sigma (E_{\nu })$ for both models and attribute the enhancement observed in the SuSAM* total cross section to the high-momentum components which are present, in a phenomenological way, in its scaling function, while these are absent in the RFG model.

    hep-phnucl-thPRD(2022)·0 citations
16. 16*

    Transverse $\Lambda$ Polarization in $e^{+}{e}^{-}$ collisions

    Leonard Gamberg🇺🇸 · Zhong-Bo Kang🇺🇸 · Ding Yu Shao🇺🇸 · John Terry🇺🇸 · Fanyi Zhao🇺🇸

    In this paper we study transverse polarization of $\Lambda$ hyperons in single-inclusive leptonic annihilation. We show that when the transverse momentum of the $\Lambda$ baryon is measured with respect to the thrust axis, a transverse momentum dependent (TMD) factorization formalism is required and the polarization is generated by the TMD polarizing fragmentation function (TMD PFF), $D_{1T}^{\perp }$. However, when the transverse momentum of the $\Lambda$ baryon is measured with respect to the momentum of the initial leptons, a collinear twist-3 formalism is required and the polarization is generated by the intrinsic collinear twist-3 fragmentation function $D_T$. Thus while these measurements differ from one another only by a change in the measurement axis, they probe different distribution functions. Recently, Belle measured a significant polarization in single-inclusive $\Lambda$ baryon production as a function of the transverse momentum with respect to the thrust axis. However, this data can in principle be re-analyzed to measure the polarization as a function of the transverse momentum of the $\Lambda$ baryon with respect to the lepton pair. This observable could be the first significant probe of the function, $D_T$. In this paper, we first develop a TMD formalism for $\Lambda$ polarization; we then present a recent twist-3 formalism that was established to describe $\Lambda$ polarization. Using the TMD formalism, we demonstrate that the $\Lambda$ polarization at OPAL and Belle can be described using the twist-2 TMD factorization formalism. Finally, we make a theoretical prediction for this polarization in the collinear twist-3 formalism at Belle.

    hep-phhep-exnucl-exnucl-thPLB(2021)·31 citations
17. 17*

    The collider tests of a leptophilic scalar for the anomalous magnetic moments

    Ning Chen🇨🇳 · Bin Wang🇨🇳 · Chang-Yuan Yao🇨🇳

    We study the anomalous muon and electron magnetic moments by introducing a scalar with CP-violating Yukawa couplings to the lepton sector. By fitting these two magnetic moments with the recent experimental measurements, we find that such a leptophilic scalar in the mass range of $\mathcal{O}(10)-\mathcal{O}(1000)\mathrm{GeV}$ can be a possible source for the current experimental deviations from the Standard Model (SM) predictions, with $\mathcal{O}(0.1)-\mathcal{O}(1)$ Yukawa couplings. The current electron and muon EDM constraints to the general CP-violating Yukawa couplings are discussed. We propose to search such a leptophilic scalar mediated at the future high-luminosity LHC (HL-LHC) runs, as well as the high-energy lepton colliders, including the CEPC and the muon collider. Our results show that the leptophilic scalar in the mass range of $\mathcal{O}(10)-\mathcal{O}(1000)\mathrm{GeV}$ can be fully probed by the future experimental searches at the HL-LHC and the lepton colliders at their early stages.

    hep-ph36 citations
18. 18*

    Astrophysical neutrino oscillations accounting for neutrino charge radii

    Konstantin Kouzakov🇷🇺 · Fedor Lazarev🇷🇺 · Vadim Shakhov🇷🇺 · Konstantin Stankevich🇷🇺 · Alexander Studenikin🇷🇺

    We derive for the first time an effective neutrino evolution Hamiltonian accounting for neutrino interactions with external magnetic field due to neutrino charge radii and anapole moment. The results are interesting for possible applications in astrophysics.

    hep-phPoS(2021)·0 citations
19. 19*

    Controlled fermion mixing and FCNCs in a $\Delta (27)$ 3+1 Higgs Doublet Model

    A. E. Cárcamo Hernández🇨🇱 · Ivo de Medeiros Varzielas🇵🇹 · M. L. López-Ibáñez🇨🇳 · Aurora Melis🇪🇪

    We propose a 3+1 Higgs Doublet Model based on the $\Delta (27)$ family symmetry supplemented by several auxiliary cyclic symmetries leading to viable Yukawa textures for the Standard Model fermions, consistent with the observed pattern of fermion masses and mixings. The charged fermion mass hierarchy and the quark mixing pattern is generated by the spontaneous breaking of the discrete symmetries due to flavons that act as Froggatt-Nielsen fields. The tiny neutrino masses arise from a radiative seesaw mechanism at one loop level, thanks to a preserved $Z_2^{\left(1\right)}$ discrete symmetry, which also leads to stable scalar and fermionic dark matter candidates. The leptonic sector features the predictive cobimaximal mixing pattern, consistent with the experimental data from neutrino oscillations. For the scenario of normal neutrino mass hierarchy, the model predicts an effective Majorana neutrino mass parameter in the range $3$~meV$\lesssim m_{\beta \beta }\lesssim$ $18$ meV, which is within the declared range of sensitivity of modern experiments. The model predicts Flavour Changing Neutral Currents which constrain the model, for instance Kaon mixing and $\mu \to e$ nuclear conversion processes, the latter which are found to be within the reach of the forthcoming experiments.

    hep-phJHEP(2021)·14 citations
20. 20*

    Energy-energy correlators in Deep Inelastic Scattering

    Hai Tao Li🇺🇸 · Yiannis Makris🇮🇹 · Ivan Vitev🇺🇸

    The energy-energy correlator (EEC) is an event shape observable which probes the angular correlations of energy depositions in detectors at high energy collider facilities. It has been investigated extensively in the context of precision QCD. In this work, we introduce a novel definition of EEC adapted to the Breit frame in deep-inelastic scattering (DIS). In the back-to-back limit, the observable we propose is sensitive to the universal transverse momentum dependent (TMD) parton distribution functions and fragmentation functions, and it can be studied within the traditional TMD factorization formalism. We further show that the new observable is insensitive to experimental pseudorapidity cuts, often imposed in the Laboratory frame due to detector acceptance limitations. In this work the singular distributions for the new observable are obtained in soft collinear effective theory up to $\mathcal{O}({\alpha }_s^3)$ and are verified by the full QCD calculations up to $\mathcal{O}({\alpha }_s^2)$. The resummation in the singular limit is performed up to next-to-next-to-next-to-leading logarithmic accuracy. After incorporating non-perturbative effects, we present a comparison of our predictions to PYTHIA 8 simulations.

    hep-phhep-exPRD(2021)·67 citations
21. 21*

    Continuum-Mediated Self-Interacting Dark Matter

    Ian Chaffey🇺🇸 · Sylvain Fichet🇧🇷 · Philip Tanedo🇺🇸

    Dark matter may self-interact through a continuum of low-mass states. This happens if dark matter couples to a strongly-coupled nearly-conformal hidden sector. This type of theory is holographically described by brane-localized dark matter interacting with bulk fields in a slice of 5D anti-de Sitter space. The long-range potential in this scenario depends on a non-integer power of the spatial separation, in contrast to the Yukawa potential generated by the exchange of a single 4D mediator. The resulting self-interaction cross section scales like a non-integer power of velocity. We identify the Born, classical and resonant regimes and investigate them using state-of-the-art numerical methods. We demonstrate the viability of our continuum-mediated framework to address the astrophysical small-scale structure anomalies. Investigating the continuum-mediated Sommerfeld enhancement, we demonstrate that a pattern of resonances can occur depending on the non-integer power. We conclude that continuum mediators introduce novel power-law scalings which open new possibilities for dark matter self-interaction phenomenology.

    hep-phastro-ph.COJHEP(2021)·29 citations
22. 22*

    Radio signatures from encounters between Neutron Stars and QCD-Axion Minihalos around Primordial Black Holes

    Sami Nurmi🇫🇮 · Enrico D. Schiappacasse🇫🇮 · Tsutomu T. Yanagida🇨🇳

    Probing the QCD axion dark matter (DM) hypothesis is extremely challenging as the axion interacts very weakly with Standard Model particles. We propose a new avenue to test the QCD axion DM via transient radio signatures coming from encounters between neutron stars (NSs) and axion minihalos around primordial black holes (PBHs). We consider a general QCD axion scenario in which the PQ symmetry breaking occurs before (or during) inflation coexisting with a small fraction of DM in the form of PBHs. The PBHs will unavoidably acquire around them axion minihalos with the typical length scale of parsecs. The axion density in the minihalos may be much higher than the local DM density, and the presence of these compact objects in the Milky Way today provides a novel chance for testing the axion DM hypothesis. We study the evolution of the minihalo mass distribution in the Galaxy accounting for tidal forces and estimate the encounter rate between NSs and the dressed PBHs. We find that the encounters give rise to transient line-like emission of radio frequency photons produced by the resonant axion-photon conversion in the NS magnetosphere and the characteristic signal could be detectable with the sensitivity of current and prospective radio telescopes. It would be important to investigate in detail search strategies for such signals which would provide a novel pathway for QCD axion detection.

    hep-phastro-ph.COastro-ph.GAastro-ph.HE+1JCAP(2021)·44 citations
23. 23*

    Dark Matter Microhalos From Simplified Models

    Nikita Blinov🇺🇸 · Matthew J. Dolan🇦🇺 · Patrick Draper🇺🇸 · Jessie Shelton🇺🇸

    We introduce simplified models for enhancements in the matter power spectrum at small scales and study their implications for dark matter substructure and gravitational observables. These models capture the salient aspects of a variety of early universe scenarios that predict enhanced small-scale structure, such as axion-like particle dark matter, light vector dark matter, and epochs of early matter domination. We use a model-independent, semi-analytic treatment to map bumps in the matter power spectrum to early-forming sub-solar mass dark matter halos and estimate their evolution, disruption, and contribution to substructure of clusters and galaxies at late times. We discuss the sensitivity of gravitational observables, including pulsar timing arrays and caustic microlensing, to both the presence of bumps in the power spectrum and variations in their basic properties.

    ↳ astro-ph.COhep-phPRD(2021)·47 citations
24. 24*

    Influence of relativistic rotation on the confinement/deconfinement transition in gluodynamics

    V.V. Braguta🇷🇺 · A.Yu. Kotov🇩🇪 · D.D. Kuznedelev🇷🇺 · A.A. Roenko🇷🇺

    In this paper we consider the influence of relativistic rotation on the confinement/deconfinement transition in gluodynamics within lattice simulation. We perform the simulation in the reference frame which rotates with the system under investigation, where rotation is reduced to external gravitational field. To study the confinement/deconfinement transition the Polyakov loop and its susceptibility are calculated for various lattice parameters and the values of angular velocities which are characteristic for heavy-ion collision experiments. Different types of boundary conditions (open, periodic, Dirichlet) are imposed in directions, orthogonal to rotation axis. Our data for the critical temperature are well described by a simple quadratic function $T_c(\Omega )/T_c(0)=1+C_2{\Omega }^2$ with $C_2>0$ for all boundary conditions and all lattice parameters used in the simulations. From this we conclude that the critical temperature of the confinement/deconfinement transition in gluodynamics increases with increasing angular velocity. This conclusion does not depend on the boundary conditions used in our study and we believe that this is universal property of gluodynamics.

    ↳ hep-lathep-phhep-thPRD(2021)·107 citations
25. 25*

    Non-flow effects in correlation between harmonic flow and transverse momentum in nuclear collisions

    Chunjian Zhang🇺🇸 · Arabinda Behera🇺🇸 · Somadutta Bhatta🇺🇸 · Jiangyong Jia🇺🇸

    A large anti-correlation signal between elliptic flow $v_2$ and average transverse momentum $[p_{\mathrm{T}}]$ was recently measured in small collision systems, consistent with a final-state hydrodynamic response to the initial geometry. This negative $v_2$-$[p_{\mathrm{T}}]$ correlation was predicted to change to positive correlation for events with very small charged particle multiplicity $N_{\mathrm{ch}}$ due to initial-state momentum anisotropies of the gluon saturation effects. However, the role of non-flow correlations is expected to be important in these systems, which is not yet studied. We estimate the non-flow effects in $pp$, $p$Pb and peripheral PbPb collisions using {\tt Pythia} and {\tt Hijing} models, and compare them with the experimental data. We show that the non-flow effects are largely suppressed using the rapidity-separated subevent cumulant method (details of the cumulant framework are also provided). The magnitude of the residual non-flow is much less than the experimental observation in the higher $N_{\mathrm{ch}}$ region, supporting the final-state response interpretation. In the very low $N_{\mathrm{ch}}$ region, however, the sign and magnitude of the residual non-flow depend on the model details. Therefore, it is unclear at this moment whether the sign change of $v_2$-$[p_{\mathrm{T}}]$ can serve as evidence for initial state momentum anisotropies predicted by the gluon saturation.

    ↳ nucl-thhep-phnucl-exPLB(2021)·27 citations
26. 26*

    Constraints on the Symmetry Energy from PREX-II in the Multimessenger Era

    Tong-Gang Yue🇨🇳 · Lie-Wen Chen🇨🇳 · Zhen Zhang🇨🇳 · Ying Zhou🇨🇳

    The neutron skin thickness $\Delta r_{\mathrm{np}}$ of heavy nuclei is essentially determined by the symmetry energy density slope $L(\rho )$ at ${\rho }_c=0.11{\mathrm{fm}}^{-3}\approx 2/3{\rho }_0$ (${\rho }_0$ is nuclear saturation density), roughly corresponding to the average density of finite nuclei. The PREX collaboration recently reported a model-independent extraction of $\Delta r_{\mathrm{np}}^{208}=0.283\pm 0.071$ fm for the $\Delta r_{\mathrm{np}}$ of ${}^{208}$Pb, suggesting a rather stiff symmetry energy $E_{\mathrm{sym}}(\rho )$ with $L({\rho }_c)\ge 52$ MeV. We show that the $E_{\mathrm{sym}}(\rho )$ cannot be too stiff and $L({\rho }_c)\le 73$ MeV is necessary to be compatible with (1) the ground-state properties and giant monopole resonances of finite nuclei, (2) the constraints on the equation of state of symmetric nuclear matter at suprasaturation densities from flow data in heavy-ion collisions, (3) the largest neutron star (NS) mass reported so far for PSR J0740+6620, (4) the NS tidal deformability extracted from gravitational wave signal GW170817 and (5) the mass-radius of PSR J0030+045 measured simultaneously by NICER. This allows us to obtain $52\le L({\rho }_c)\le 73$ MeV and $0.212\le \Delta r_{\mathrm{np}}^{208}\le 0.271$ fm, and further $E_{\mathrm{sym}}({\rho }_0)=34.3\pm 1.7$ MeV, $L({\rho }_0)=83.1\pm 24.7$ MeV, and $E_{\mathrm{sym}}(2{\rho }_0)=62.8\pm 15.9$ MeV. A number of critical implications on nuclear physics and astrophysics are discussed.

    ↳ nucl-thastro-ph.HEhep-phnucl-exPRResearch(2022)·75 citations
27. 27*

    Baryonic matter and the medium modification of the baryon masses

    Nam-Yong Ghim🇰🇷 · Ghil-Seok Yang🇰🇷 · Hyun-Chul Kim🇰🇷 · Ulugbek Yakhshiev🇰🇷

    We investigate the properties of baryonic matter within the framework of the in-medium modified chiral soliton model by taking into account the effects of surrounding baryonic environment on the properties of in-medium baryons. The internal parameters of the model are determined based on nuclear phenomenology at nonstrange sector and fitted by reproducing nuclear matter properties near the saturation point. We discuss the equations of state in different nuclear environments such as symmetric nuclear matter, neutron and strange matters. We show that the results for the equations of state are in good agreement with the phenomenology of nuclear matter. We also discuss how the SU(3) baryons masses undergo changes in these various types of nuclear matter.

    ↳ nucl-thastro-ph.HEhep-phnucl-exPRC(2021)·5 citations
28. 28*

    Narrowing the mass range of Fuzzy Dark Matter with Ultra-faint Dwarfs

    Kohei Hayashi🇯🇵 · Elisa G. M. Ferreira🇩🇪 · Hei Yin Jowett Chan🇯🇵

    Fuzzy dark matter (FDM) is an attractive dark matter candidate motivated by small scale problems in astrophysics and with a rich phenomenology on those scales. We scrutinize the FDM model, more specifically the mass of the FDM particle, through a dynamical analysis for the Galactic ultra-faint dwarf (UFD) galaxies. We use a sample of 18 UFDs to place the strongest constraints to date on the mass of the FDM particle, updating on previous bounds using a subset of the sample used here. We find that most of the sample UFDs prefer a FDM particle mass heavier than $10^{-21}\mathrm{eV}$. In particular, Segue 1 provides the strongest constraint, with $m_{\psi }=1.1_{-0.7}^{+8.3}\times 10^{-19}\mathrm{eV}$. The constraints found here are the first that are compatible with various other independent cosmological and astrophysical bounds found in the literature, in particular with the latest bounds using the Lyman-$\alpha$ forest. We also find that the constraints obtained in this work are not compatible with the bounds from luminous dwarf galaxies, as already pointed out in the previous work using UFDs. This could indicate that although a viable dark matter model, it might be challenging for the FDM model to solve the small scale problems.

    ↳ astro-ph.COastro-ph.GAhep-phApJL(2021)·84 citations
29. 29*

    Detecting the flavor content of the vacuum using the Dirac operator spectrum

    Jian Liang🇨🇳 · Andrei Alexandru🇺🇸 · Yu-Jiang Bi🇨🇳 · Terrence Draper🇺🇸 · Keh-Fei Liu🇺🇸 · Yi-Bo Yang🇨🇳

    We compute the overlap Dirac spectrum on three gauge ensembles generated using $2+1$-flavor domain wall fermions. The three ensembles have different lattice spacings and two of them have quark masses tuned to the physical point. The spectral density is determined up to $\lambda \sim$100 MeV with subpercentage statistical uncertainty. We find that the density is close to a constant below $\lambda \sim$ 20 MeV as predicted by chiral perturbative theory ($\chi$PT), and then increases linearly due to the strange quark mass. By fitting to the next-to-leading order $\chi$PT form and using the non-perturbative RI/MOM renormalization, the $\mathrm{SU}(2)$ (keeping the strange quark mass at the physical point) and $\mathrm{SU}(3)$ chiral condensates at $\overline{\text{MS}}$ 2 GeV are determined to be $\Sigma =(265.4(0.5)(4.2)\text{MeV}{)}^3$ and ${\Sigma }_0=(234.3(0.5)(25.8)\text{MeV}{)}^3$, respectively. The pion decay constants are also determined to be $F=84.1(1.9)(8.0)$ and $F_0=58.6(0.5)(10.0)$ MeV. The systematic errors are carefully estimated including the effects of fitting ranges and the uncertainty of low-energy constant $L_6$. We also show that one can resolve the sea flavor content of the sea quarks and constrain their masses with {$\sim 10\%-20\%$} statistical uncertainties using the Dirac spectral density.

    ↳ hep-lathep-phPRD(2024)·16 citations
30. 30*

    Sequential single pion production explaining the dibaryon "$d^{\ast }(2380)$" peak

    R. Molina · N. Ikeno · E. Oset

    We study the two step sequential one pion production mechanism, $np(I=0)\to {\pi }^{-}pp$, followed by the fusion reaction $pp\to {\pi }^{+}d$, in order to describe the $np\to {\pi }^{+}{\pi }^{-}d$ reaction with ${\pi }^{+}{\pi }^{-}$ in $I=0$, where a narrow peak, so far identified with a "$d(2380)$" dibaryon, has been observed. We find that the second step $pp\to {\pi }^{+}d$ is driven by a triangle singularity that determines the position of the peak of the reaction and the large strength of the cross section. The combined cross section of these two mechanisms produce a narrow peak with the position, width and strength compatible with the experimental observation within the approximations done. This novel interpretation of the peak without invoking a dibaryon explains why the peak is not observed in other reactions where it has been searched for.

    ↳ nucl-thhep-exhep-phChin.Phys.C 47 (2023) 4, 041001
31. 31*

    Constant-rate inflation: primordial black holes from conformal weight transitions

    Kin-Wang Ng🇹🇼 · Yi-Peng Wu🇫🇷

    Constant-rate inflation, including ultra-slow-roll as a special case, has been widely applied to the formation of primordial black holes with significant deviation from the standard slow-roll conditions at both the growing and decaying phases of the power spectrum. We derive analytic solutions for the curvature perturbations with respect to the late-time scaling dimensions (conformal weights) constrained by the dilatation symmetry of the de Sitter background and show that the continuity of conformal weights across different rolling phases is protected by the adiabatic condition of the inflaton perturbation. The temporal excitation of subleading states (with the next-to-lowest conformal weights), recorded as the "steepest growth" of the power spectrum, is triggered by the entropy production in the transition from slow-roll to constant-rate phases.

    ↳ astro-ph.COhep-phhep-thJHEP(2021)·47 citations
32. 32*

    Touch of Neutrinos on the Vacuum Metamorphosis: is the $H_0$ Solution Back?

    Eleonora Di Valentino🇬🇧 · Supriya Pan🇮🇳 · Weiqiang Yang🇨🇳 · Luis A. Anchordoqui🇺🇸

    With the entrance of cosmology in its new era of high precision experiments, low- and high-redshift observations set off tensions in the measurements of both the present-day expansion rate ($H_0$) and the clustering of matter ($S_8$). We provide a simultaneous explanation of these tensions using the Parker-Raval Vacuum Metamorphosis (VM) model with the neutrino sector extended beyond the three massless Standard Model flavours and the curvature of the universe considered as a model parameter. To estimate the effect on cosmological observables we implement various extensions of the VM model in the standard \texttt{CosmoMC} pipeline and establish which regions of parameter space are empirically viable to resolve the $H_0$ and $S_8$ tensions. We find that the likelihood analyses of the physically motivated VM model, which has the same number of free parameters as in the spatially-flat $\Lambda$CDM model, always gives $H_0$ in agreement with the local measurements (even when BAO or Pantheon data are included) at the price of much larger ${\chi }^2$ than $\Lambda$CDM. The inclusion of massive neutrinos and extra relativistic species quantified through two well known parameters $\sum m_{\nu }$ and $N_{\mathrm{eff}}$, does not modify this result, and in some cases improves the goodness of the fit. In particular, for the original VM+$\sum m_{\nu }$+$N_{\mathrm{eff}}$ and the Planck+BAO+Pantheon dataset combination, we find evidence for $\sum m_{\nu }=0.80_{-0.22}^{+0.18}\mathrm{eV}$ at more than $3\sigma$, no indication for extra neutrino species, $H_0=71.0\pm 1.2$~km/s/Mpc in agreement with local measurements, and $S_8=0.755\pm 0.032$ that solves the tension with the weak lensing measurements. [Abridged]

    ↳ astro-ph.COgr-qchep-phPRD(2021)·38 citations
33. 33*

    Non-Gaussian Stochastic Gravitational Waves from Phase Transitions

    Soubhik Kumar🇺🇸 · Raman Sundrum🇺🇸 · Yuhsin Tsai🇺🇸

    Cosmological phase transitions in the primordial universe can produce anisotropic stochastic gravitational wave backgrounds (GWB), similar to the cosmic microwave background (CMB). For adiabatic perturbations, the fluctuations in GWB follow those in the CMB, but if primordial fluctuations carry an isocurvature component, this need no longer be true. It is shown that in non-minimal inflationary and reheating settings, primordial isocurvature can survive in GWB and exhibit significant non-Gaussianity (NG) in contrast to the CMB, while obeying current observational bounds. While probing such NG GWB is at best a marginal possibility at LISA, there is much greater scope at future proposed detectors such as DECIGO and BBO. It is even possible that the first observations of inflation-era NG could be made with gravitational wave detectors as opposed to the CMB or Large-Scale Structure surveys.

    ↳ astro-ph.COgr-qchep-phJHEP(2021)·39 citations
34. 34*

    Positivity Bounds without Boosts

    Tanguy Grall🇬🇧 · Scott Melville🇬🇧

    We derive the first positivity bounds for low-energy Effective Field Theories (EFTs) that are not invariant under Lorentz boosts. "Positivity bounds" are the low-energy manifestation of certain fundamental properties in the UV -- to date they have been used to constrain a wide variety of EFTs, however since all of the existing bounds require Lorentz invariance they are not directly applicable when this symmetry is broken, such as for most cosmological and condensed matter systems. From the UV axioms of unitarity, causality and locality, we derive an infinite family of bounds which (derivatives of) the $2\to 2$ EFT scattering amplitude must satisfy even when Lorentz boosts are broken (either spontaneously or explicitly). We apply these bounds to the leading-order EFT of both a superfluid and the scalar fluctuations produced during inflation, comparing in the latter case with the current observational constraints on primordial non-Gaussianity.

    ↳ hep-thgr-qchep-phPRD(2022)·79 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.