Tue·Aug 18, 2020Tuesday·August 18, 2020

1. 01*

   GANplifying Event Samples

   Anja Butter🇩🇪 · Sascha Diefenbacher🇩🇪 · Gregor Kasieczka🇩🇪 · Benjamin Nachman🇺🇸 · Tilman Plehn🇩🇪

   A critical question concerning generative networks applied to event generation in particle physics is if the generated events add statistical precision beyond the training sample. We show for a simple example with increasing dimensionality how generative networks indeed amplify the training statistics. We quantify their impact through an amplification factor or equivalent numbers of sampled events.

   hep-phhep-exphysics.data-anstat.MLSciPost Phys.(2021)·120 citations
2. 02*

   Probing the Dark Matter of Three-loop Radiative Neutrino Mass Generation Model with the Cherenkov Telescope Array

   Talal Ahmed Chowdhury🇧🇩 · Saquib Hassan🇬🇧 · Jahid Hossain🇺🇸 · Salah Nasri🇦🇪 · Mahmud Ashraf Shamim🇧🇩

   We investigate the prospect of detecting the Dark Matter (DM) candidate in the three-loop radiative neutrino mass generation model extended with large electroweak multiplets of the Standard Model (SM) gauge group, at the future imaging atmospheric Cherenkov telescope known as the Cherenkov Telescope Array (CTA). We find that the addition of such large electroweak multiplets leads to a sizable Sommerfeld enhanced annihilation of the DM with $O(\text{TeV})$ mass, into the SM gauge bosons which results in continuum and line-like spectra of very high energy (VHE) gamma-rays, and therefore becomes observable for the CTA. We determine the viable models by setting the upper limit on the $SU(2{)}_L$ isospin of the multiplets from the partial-wave unitarity constraints and the appearance of low-scale Landau pole in the gauge coupling. Afterwards, by considering the continuum VHE gamma-rays produced from the DM annihilation at the Galactic center, we probe the parameter space of the model using the sensitivity reach of the CTA.

   hep-phastro-ph.HEPRD(2021)·2 citations
3. 03*

   Studying Radiative Baryon Decays with the SU(3) Flavor Symmetry

   Ru-Min Wang🇨🇳 · Xiao-Dong Cheng🇨🇳 · Ying-Ying Fan🇨🇳 · Jie-Lei Zhang🇨🇳 · Yuan-Guo Xu🇨🇳

   The weak and electromagnetic radiative baryon decays of octet $T_8$, decuplet $T_{10}$, single charmed anti-triplet $T_{c3}$ and sextet $T_{c6}$, single heavy bottomed anti-triplet $T_{b3}$ and sextet $T_{b6}$ are investigated by using SU(3) flavor symmetry irreducible representation approach. We analyze the contributions from a single quark transition $q_1\to q_2\gamma$ and $W$ exchange transitions, and find that the amplitudes could be easily related by SU(3) flavor symmetry in the $T_{b3,b6}$ weak radiative decays, $T_{c3,c6}$ weak radiative decays, $T_{10}\to T_8\gamma$ weak decays, $T_{10}\to T_{10}^{\prime }\gamma$ weak decays and $T_{10}\to T_8\gamma$ electromagnetic decays. Nevertheless, the amplitude relations are a little complex in the $T_8\to T_8^{\prime }\gamma$ and $T_8\to T_{10}\gamma$ weak decays due to quark antisymmetry in $T_8$ and $W$ exchange contributions. Predictions for branching ratios of ${\Lambda }_b^0\to n\gamma$, ${\Xi }_b^{-}\to {\Xi }^{-}\gamma$, ${\Xi }_b^{-}\to {\Sigma }^{-}\gamma$, ${\Xi }_b^0\to {\Sigma }^0\gamma$, ${\Xi }_b^0\to {\Lambda }^0\gamma$, ${\Xi }_b^0\to {\Xi }^0\gamma$, ${\Xi }^{\ast }\to \Xi \gamma$, ${\Sigma }^{\ast 0}\to {\Sigma }^0\gamma$, ${\Delta }^0\to n\gamma$ and ${\Delta }^{+}\to p\gamma$ are given. The results in this work can be used to test SU(3) flavor symmetry approach in the radiative baryon decays by the future experiments at BESIII, LHCb and Belle-II.

   hep-phJ.Phys.G(2021)·28 citations
4. 04*

   Strong force fields and stabilities of the nucleon and singly heavy baryon ${\Sigma }_c$

   June-Young Kim🇩🇪 · Hyun-Chul Kim🇰🇷 · Maxim V. Polyakov🇩🇪 · Hyeon-Dong Son🇩🇪

   We investigate the strong force fields and stabilities of the nucleon and the singly heavy baryon ${\Sigma }_c$ within the framework of the chiral quark-soliton model. Having constructed the pion mean fields in the presence of the $N_c-1$ level quarks self-consistently, we are able to examine the gravitational form factors of ${\Sigma }_c$. We mainly focus in the present work on the stability conditions for both the nucleon and ${\Sigma }_c$ and discuss the strong force fields and their physical implications. We also present the results for the gravitational form factors and relevant observables, emphasising the difference between the nucleon and ${\Sigma }_c$.

   hep-phhep-exhep-latPRD(2021)·35 citations
5. 05*

   Characterisation of Dark Matter in Direct Detection Experiments: Singlino Versus Higgsino

   Yaşar Hiçyılmaz🇬🇧 · Stefano Moretti🇬🇧

   We show how the material used in direct detection experiments of Dark Matter (DM), in the presence of a signal of it, can afford one with the possibility of extracting the nature of the underlying candidate. We do so for the case of a $U(1{)}^{\prime }$ Supersymmetric Standard Model (USSM) of E${}_6$ origin, by exploiting benchmark points over its parameter space that yield either a Singlino- or Higgsino-like neutralino as DM candidate, the latter being defined in presence of up-to-date constraints, from low to high energy and from collider to non-collider experiments. However, as our method is general, we also introduce a model-independent description of our analysis, for the purpose of aiding similar studies in other Beyond the Standard Model (BSM) scenarios. This has been made possible by adapting a rather simple ${\chi }^2$ analysis normally used for signal extraction in direct detection experiments and the procedure has been applied to Xenon, Germanium and Silicon detectors, those showing maximal and complementary sensitivity to gauge- and Higgs-portal induced interactions of DM with their nuclei.

   hep-phNPB(2021)·6 citations
6. 06*

   Inert sextuplet scalar dark matter at the LHC and future colliders

   Dan-Yang Liu🇨🇳 · Chengfeng Cai🇨🇳 · Zhao-Huan Yu🇨🇳 · Yu-Pan Zeng🇨🇳 · Hong-Hao Zhang🇨🇳

   We study a dark matter model constructed by extending the standard model with an inert $\mathrm{SU}(2{)}_{\mathrm{L}}$ sextuplet scalar of hypercharge 1/2. The sextuplet components are split by the quartic couplings between the sextuplet and the Higgs doublet after electroweak symmetry breaking, resulting in a dark sector with one triply charged, two doubly charged, two singly charged, and two neutral scalars. The lighter neutral scalar boson acts as a dark matter particle. We investigate the constraints on this model from the $\text{monojet}+/E_{\mathrm{T}}$ and $\text{soft-dilepton}+\text{jets}+/E_{\mathrm{T}}$ searches at the 13 TeV Large Hadron Collider, as well as from the current electroweak precision test. Furthermore, we estimate the projected sensitivities of a 100 TeV $pp$ collider and of a future $e^{+}{e}^{-}$ collider, and find that such future projects could probe TeV mass scales. Nonetheless, such mass scales only correspond to a subdominant component of the observed relic abundance if the dark matter particles solely originate from thermal production.

   hep-phJHEP(2020)·4 citations
7. 07*

   The Nakano-Nishijima-Gell-Mann Formula From Discrete Galois Fields

   Keiji Nakatsugawa🇯🇵 · Motoo Ohaga🇯🇵 · Toshiyuki Fujii🇯🇵 · Toyoki Matsuyama🇯🇵 · Satoshi Tanda🇯🇵

   The well known Nakano-Nishijima-Gell-Mann (NNG) formula relates certain quantum numbers of elementary particles to their charge number. This equation, which phenomenologically introduces the quantum numbers $I_z$ (isospin), $S$ (strangeness), etc., is constructed using group theory with real numbers $\mathbb{R}$. But, using a discrete Galois field ${\mathbb{F}}_p$ instead of $\mathbb{R}$ and assuring the fundamental invariance laws such as unitarity, Lorentz invariance, and gauge invariance, we derive the NNG formula deductively from Meson (two quarks) and Baryon (three quarks) representations in a unified way. Moreover, we show that quark confinement ascribes to the inevitable fractionality caused by coprimeness between half-integer (1/2) of isospin and number of composite particles (e.g. three).

   hep-phhep-thSymmetry(2020)·1 citation
8. 08*

   The $X_0(2900)$ and its heavy quark spin partners in molecular picture

   Mei-Wei Hu🇨🇳 · Xue-Yi Lao🇨🇳 · Pan Ling🇨🇳 · Qian Wang🇨🇳

   The $X_0(2900)$ observed by the LHCb Collaboration recently in the $D^{-}{K}^{+}$ invariant mass of the $B^{+}\to D^{+}{D}^{-}{K}^{+}$ process is the first exotic candidate with four different flavors, which opens a new era for the hadron community. Under the assumption that the $X_0(2900)$ is a $I(J^P)=0(0^{+})$ ${\bar{D}}^{\ast }{K}^{\ast }$ hadronic molecule, we extract the whole heavy-quark symmetry multiplet formed by the $\left(\bar{D},{\bar{D}}^{\ast }\right)$ doublet and the $K^{\ast }$ meson. For the bound state case, there would be two additional $I(J^P)=0(1^{+})$ hadronic molecules associated with the $\bar{D}{K}^{\ast }$ and ${\bar{D}}^{\ast }{K}^{\ast }$ channels as well as one additional $I(J^P)=0(2^{+})$ ${\bar{D}}^{\ast }{K}^{\ast }$ molecule. In the light quark limit, they are $36.66\mathrm{MeV}$ and $34.22\mathrm{MeV}$ below the $\bar{D}{K}^{\ast }$ and ${\bar{D}}^{\ast }{K}^{\ast }$ thresholds, respectively, which are unambiguously fixed by the mass position of the $X_0(2900)$. For the virtual state case, there would be one additional $I(J^P)=0(1^{+})$ hadronic molecule strongly coupling to the $\bar{D}{K}^{\ast }$ channel and one additional $I(J^P)=0(2^{+})$ ${\bar{D}}^{\ast }{K}^{\ast }$ molecule. Searching for these heavy quark spin partners will help shed light on the nature of the $X_0(2900)$.

   hep-phCPC(2021)·77 citations
9. 09*

   Searching for exotic B meson decays with the CMS L1 track trigger

   Jared A. Evans🇺🇸 · Abhijith Gandrakota🇺🇸 · Simon Knapen🇨🇭 · Hardik Routray🇺🇸

   The CMS phase II track trigger may allow for a displaced dimuon vertex trigger with qualitatively lower $p_T$ thresholds than existing dimuon triggers. With this technique, we show that the CMS reach for exotic $B$-meson decays involving a displaced dimuon resonance, such as a light, Higgs-mixed scalar, can be competitive with that of LHCb and Belle II.

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

    Determination of the masses and decay widths of the well-established $s$ and $p$ baryon resonances below $2$ GeV

    Evangelos Matsinos

    This study appertains to the extraction of estimates for the masses and for the partial decay widths to pion-nucleon final states of the well-established (four-star) $s$ and $p$ baryon resonances below $2$ GeV. These estimates are exclusively obtained from the data contained in the recent compilation by the Particle Data Group. Only the $N$ ($S=0,I=1/2$) and the $\Delta$ ($S=0,I=3/2$) states are considered, where $S$ and $I$ denote strangeness and total isospin, respectively.

    hep-phnucl-th3 citations
11. 11*

    Modification of T/E models and their multi-field versions

    Ping Kwan Man Ellgan🇯🇵

    We propose a modification on the super-potential of (arXiv: 1901.09046) which discusses the simplest construction of inflationary $\alpha$ attractor models (also called T/E models) in supergravity without the sinflaton. This can make all the components of the first derivative vanish at the minimum point after the specific choice for the modified part. We also extend T/E models into the multi-field versions, motivated by considering the effect of multi orthogonal nilpotent super-fields, whose sgoldstino, sinflatons and inflatinos are very heavy such that we can take the orthogonal nilpotent constraints to obtain physical limits. Finally, we study the inflation dynamics in the double field cases of both T and E models and show their turning rates and the square mass of the entropic perturbation, which can be used for further observational verification.

    hep-phgr-qcJCAP(2020)·0 citations
12. 12*

    Kinetic mixing, custodial symmetry and a lower bound on the dark $Z^{\prime }$ mass

    M. Napsuciale🇲🇽 · S. Rodríguez🇲🇽 · H. Hernández-Arellano🇲🇽

    In this work we consider the extension of the standard model by dark fields with an Abelian $U(1{)}_d$ spontaneously broken gauge symmetry in a hidden dark matter scenario. Considering all the dimension four gauge invariant terms we show that the tree-level relation $M_W^2=M_{\tilde{Z}}^2{\cos }^2{\tilde{\theta }}_w$ holds and permits to write the mixing angle induced by the kinetic mixing in the neutral massive gauge boson sector, ${\theta }_{\zeta }$, in terms of the values of $M_Z$, the weak mixing angle and of the mass of the physical dark gauge $Z^{\prime }$ boson. At the loop level, a similar relation is obtained in the $\overline{MS}$ scheme. Using the result extracted from the global fit to electroweak precision data for the ratio ${\rho }_0=M_W^2/{\hat{c}}_Z^2{M}_Z^2\hat{\rho }$, we obtain a lower bound $M_{Z^{\prime }}>M_Z$ for the dark $Z^{\prime }$ mass at the $94\%$ confidence level. We argue that this lower bound holds in the general case of theories for physics beyond the standard model with an extra $U(1)$ gauge factor subgroup, whenever the extended Higgs potential respects custodial symmetry.

    hep-phPTEP(2022)·3 citations
13. 13*

    Constraints on cosmic-ray boosted DM in CDEX-10

    Zhan-Hong Lei🇨🇳 · Jian Tang🇨🇳 · Bing-Long Zhang🇨🇳

    Dark matter (DM) direct detection experiments have been setting strong limits on the DM-nucleon scattering cross section at the DM mass above a few GeV, but leave large parameter space unexplored in the low mass region. DM is likely to be scattered and boosted by relativistic cosmic rays in the expanding universe if it can generate nuclear recoils in direct detection experiments to offer observable signals. Since low energy threshold detectors using Germanium have provided good constraints on ordinary halo GeV-scale DM, it is necessary to re-analyze 102.8 kg$\times$day data in the CDEX-10 experiment assuming that DM is boosted by cosmic rays. For the DM mass range 1 keV $<m_{\chi }<$ 1 MeV and the effective distance within 1 kpc, we reach an almost flat floor limit at $8.32\times 10^{-30}$ cm${}^2$ on spin-independent DM-nucleon scattering cross section at a 90\% confidence level. The CDEX-10 result is able to close the gap unambiguously in the parameter space between MiniBooNE and XENON1T constraints which was partially hindered by the Earth attenuation effect. We also quantitatively calculate expected neutrino floor on searching for CRBDM in future direct detection experiments using Germanium.

    hep-phhep-exCPC(2022)·38 citations
14. 14*

    Open-charm tetraquark $X_c$ and open-bottom tetraquark $X_b$

    Xiao-Gang He🇹🇼 · Wei Wang🇨🇳 · Ruilin Zhu🇨🇳

    Motivated by the LHCb observation of exotic states $X_{0,1}(2900)$ with four open quark flavors in the $D^{-}{K}^{+}$ invariant mass distribution in the decay channel $B^{\pm }\to D^{+}{D}^{-}{K}^{\pm }$, we study the spectrum and decay properties of the open charm tetraquarks. Using the two-body chromomagnetic interactions, we find that the two newly observed states can be interpreted as a radial excited tetraquark with $J^P=0^{+}$ and an orbitally excited tetraquark with $J^P=1^{-}$, respectively. We then explore the mass and decays of the other flavor-open tetraquarks made of $su\bar{d}\bar{c}$ and $ds\bar{u}\bar{c}$, which are in the $\bar{6}$ or $15$ representation of the flavor SU(3) group. We point that these two states can be found through the decays: $X_{ds\bar{u}\bar{c}}^{(\prime )}\to (D^{-}{K}^{-},D_s^{-}{\pi }^{-})$, and $X_{su\bar{d}\bar{c}}^{(\prime )}\to D_s^{-}{\pi }^{+}$. We also apply our analysis to open bottom tetraquark $X_b$ and predict their masses. The open-flavored $X_b$ can be discovered through the following decays: $X_{ud\bar{s}\bar{b}}\to B^0{K}^{+}$, $X_{ds\bar{u}\bar{b}}^{(\prime )}\to (B^0{K}^{-},B_s^0{\pi }^{-})$, and $X_{su\bar{d}\bar{b}}^{(\prime )}\to B_s^0{\pi }^{+}$.

    hep-phhep-exEPJC(2020)·89 citations
15. 15*

    Triangle singularity as the origin of $X_0(2900)$ and $X_1(2900)$ observed in $B^{+}\to D^{+}{D}^{-}{K}^{+}$

    Xiao-Hai Liu🇨🇳 · Mao-Jun Yan🇨🇳 · Hong-Wei Ke🇨🇳 · Gang Li🇨🇳 · Ju-Jun Xie🇨🇳

    The LHCb collaboration reported the observation of a narrow peak in the $D^{-}{K}^{+}$ invariant mass distributions from the $B^{+}\to D^{+}{D}^{-}{K}^{+}$ decay. The peak is parameterized in terms of two resonances $X_0(2900)$ and $X_1(2900)$ with the quark contents $\bar{c}\bar{s}ud$, and their spin-parity quantum numbers are $0^{+}$ and $1^{-}$, respectively. We investigate the rescattering processes which may contribute to the $B^{+}\to D^{+}{D}^{-}{K}^{+}$ decays. It is shown that the $D^{\ast -}{K}^{\ast +}$ rescattering via the ${\chi }_{c1}{K}^{\ast +}{D}^{\ast -}$ loop or the ${\bar{D}}_1^0{K}^0$ rescattering via the $D_{sJ}^{+}{\bar{D}}_1^0{K}^0$ loop simulate the $X_0(2900)$ and $X_1(2900)$ structures. Such phenomena are due to the analytical property of the scattering amplitudes with the triangle singularities located to the vicinity of the physical boundary.

    hep-phhep-exnucl-exnucl-thEPJC(2020)·92 citations
16. 16*

    Rare $b\to d$ decays in covariant confined quark model

    Nakul R. Soni🇮🇳 · Aidos Issadykov🇷🇺 · Akshay N. Gadaria🇮🇳 · Janaki J. Patel🇮🇳 · Jignesh N. Pandya🇮🇳

    In this article, we study the rare decays corresponding to $b\to d$ transition in the framework of the covariant confined quark model. The transition form factors for the channels $B^{+(0)}\to ({\pi }^{+(0)},{\rho }^{+(0)},\omega )$ and $B_s^0\to K^{(\ast )0}$ are computed in the entire dynamical range of momentum transfer squared. Using the form factors, we compute the branching fractions of the rare decays and our results are found to be matching well with the experimental data. We also compute the ratios of the branching fractions of the $b\to s$ to $b\to d$ rare decays using the inputs from previous papers on $b\to s{\ell }^{+}{\ell }^{-}$ using this model. Further, using the form factors, model dependent and independent parameters, we also compute different other physical observables such as forward backward asymmetry, longitudinal polarization and angular observables in the entire $q^2$ range as well as in $q^2$ bins [0.1 -- 0.98] GeV${}^2$ and [1.1 -- 6] GeV${}^2$. We also compare our findings with different theoretical predictions.

    hep-phEPJA(2022)·21 citations
17. 17*

    Estimates for the single-spin asymmetries in $p^{\uparrow }p\to J/\psi X$ process at PHENIX RHIC and SPD NICA

    Anton Karpishkov🇷🇺 · Maxim Nefedov🇷🇺 · Vladimir Saleev🇷🇺

    We study the transverse single-spin asymmetry (TSSA) in $p^{\uparrow }p\to J/\psi X$ reaction, incorporating both transverse-momentum and spin effects. To predict production cross section of prompt $J/\psi$ we use two different approaches, the non-relativistic QCD (NRQCD) factorization approach and the Improved Color Evaporation Model (ICEM), and show how the predicted results for TSSAs depend on choice of hadronization model. For initial-state factorization we consider two models: the standard Generalized Parton Model (GPM) and the Colour Gauge-Invariant version of it (CGI-GPM). We demonstrate that PHENIX collaboration data on TSSA in the process $p^{\uparrow }p\to J/\psi X$ constrain the gluon Sivers function of the proton and rule-out one of existing parameterizations. Estimates for the TSSAs in $p^{\uparrow }p\to J/\psi X$ process for the conditions of the future SPD NICA experiment are presented for the first time.

    hep-phPRD(2021)·7 citations
18. 18*

    An open charm tetraquark candidate: note on $X_0(2900)$

    Jian-Rong Zhang🇨🇳

    Motivated by the LHCb's very recent observation of exotic $X_0(2900)$ in the $B^{+}\to D^{+}{D}^{-}{K}^{+}$ process, for which could be a good open charm $ud\bar{c}\bar{s}$ tetraquark candidate, we endeavor to investigate its possibility by means of QCD sum rules. In technique, four configurations of interpolating currents with $J^P=0^{+}$ are studied for the $ud\bar{c}\bar{s}$ tetraquark state. In the end, mass values are calculated to be $2.76_{-0.23}^{+0.16}\text{mbox}GeV$ for the axial vector diquark-axial vector antidiquark configuration and $2.75_{-0.24}^{+0.15}\text{mbox}GeV$ for the scalar diquark-scalar antidiquark configuration, both of which are consistent with the experimental data $2.866\pm 0.007\pm 0.002\text{mbox}GeV$ of $X_0(2900)$ in view of the uncertainty. These results support that $X_0(2900)$ could be a $0^{+}$ tetraquark state with open charm flavor.

    hep-phhep-exPRD(2021)·69 citations
19. 19*

    Open charm and bottom tetraquarks in an extended relativized quark model

    Qi-Fang Lü🇨🇳 · Dian-Yong Chen🇨🇳 · Yu-Bing Dong🇨🇳

    In present work, we systematically calculate the mass spectra of open charm and bottom tetraquarks $qq\bar{q}\bar{Q}$ within an extended relativized quark model. The four-body relativized Hamiltonians including the Coulomb potential, confining potential, spin-spin interactions, and relativistic corrections are solved by using the variational method. It is found that the predicted masses of four $0^{+}$ $ud\bar{s}\bar{c}$ states are 2765, 3065, 3152, and 3396 MeV, which disfavor the assignment of the newly observed $X_0(2900)$ as a compact tetraquark. Moreover, the whole mass spectra of the open charm and bottom tetraquarks show quite similar patterns, which preserve the light flavor SU(3) symmetry and heavy quark symmetry well. In addition, our results suggest that the flavor exotic states $nn\bar{s}\bar{c}$, $nn\bar{s}\bar{b}$, $ss\bar{n}\bar{c}$, and $ss\bar{n}\bar{b}$ and their antiparticles can be searched in the heavy-light meson plus kaon final states by future experiments. More theoretical and experimental efforts are needed to investigate these singly heavy tetraquarks.

    hep-phhep-exnucl-thPRD(2020)·79 citations
20. 20*

    $Z$-boson hadronic decay width up to $\mathcal{O}({\alpha }_s^4)$-order QCD corrections using the single-scale approach of the principle of maximum conformality

    Xu-Dong Huang🇨🇳 · Xing-Gang Wu🇨🇳 · Xu-Chang Zheng🇨🇳 · Qing Yu🇨🇳 · Sheng-Quan Wang🇨🇳 · Jian-Ming Shen🇨🇳

    In the paper, we study the properties of the $Z$-boson hadronic decay width by using the $\mathcal{O}({\alpha }_s^4)$-order quantum chromodynamics (QCD) corrections with the help of the principle of maximum conformality (PMC). By using the PMC single-scale approach, we obtain an accurate renormalization scale-and-scheme independent perturbative QCD (pQCD) correction for the $Z$-boson hadronic decay width, which is independent to any choice of renormalization scale. After applying the PMC, a more convergent pQCD series has been obtained; and the contributions from the unknown $\mathcal{O}({\alpha }_s^5)$-order terms are highly suppressed, e.g. conservatively, we have $\Delta {\Gamma }_{\mathrm{Z}}^{\mathrm{had}}{|}_{\mathrm{PMC}}^{\mathcal{O}({\alpha }_s^5)}\simeq \pm 0.004$ MeV. In combination with the known electro-weak (EW) corrections, QED corrections, EW-QCD mixed corrections, and QED-QCD mixed corrections, our final prediction of the hadronic $Z$ decay width is ${\Gamma }_{\mathrm{Z}}^{\mathrm{had}}=1744.439_{-1.433}^{+1.390}$ MeV, which agrees with the PDG global fit of experimental measurements, $1744.4\pm 2.0$ MeV.

    hep-phEPJC(2021)·6 citations
21. 21*

    Hunting BFKL in semi-hard reactions at the LHC

    Francesco Giovanni Celiberto🇮🇹

    The agreement between calculations inspired by the resummation of energy logarithms, known as BFKL approach, and experimental data in the semi-hard sector of QCD has become manifest after a wealthy series of phenomenological analyses. However, the contingency that the same data could be concurrently portrayed at the hand of fixed-order, DGLAP-based calculations, has been pointed out recently, but not yet punctually addressed. Taking advantage of the richness of configurations gained by combining the acceptances of CMS and CASTOR detectors, we give results in the full next-to-leading logarithmic approximation of cross sections, azimuthal correlations and azimuthal distributions for three distinct semi-hard processes, each of them featuring a peculiar final-state exclusiveness. Then, making use of disjoint intervals for the transverse momenta of the emitted objects, i.e. $\kappa$-windows, we clearly highlight how high-energy resummed and fixed-order driven predictions for semi-hard sensitive observables can be decisively discriminated in the kinematic ranges typical of current and forthcoming analyses at the LHC. The scale-optimization issue is also introduced and explored, while the uncertainty coming from the use of different PDF and FF set is deservedly handled. Finally, a brief overview of JETHAD, a numerical tool recently developed, suited for the computation of inclusive semi-hard reactions is provided.

    hep-phhep-thEPJC(2021)·106 citations
22. 22*

    $X_0(2866)$ as a $D^{\ast }{\bar{K}}^{\ast }$ molecular state

    Ming-Zhu Liu🇨🇳 · Ju-Jun Xie🇨🇳 · Li-Sheng Geng🇨🇳

    Very recently the LHCb Collaboration reported the discovery of two open charm tetraquark states, $X_0(2866)$ and $X_1(2904)$. In the present work, we study the $D^{(\ast )}$ and ${\bar{K}}^{(\ast )}$ interaction in the one-boson exchange model and show that the $X_0(2866)$ can be understood as a $D^{\ast }{\bar{K}}^{\ast }$ molecule with $I(J^P)=0(0^{+})$, or at least it has a large molecular component. On the other hand, the $X_1(2904)$ can not be interpreted as a molecular state. Inspired by the discovery of the $X_0(2866)$ and the fact that the $D^{\ast }{\bar{K}}^{\ast }$ interaction is strong enough to generate a bound state, we also discuss likely existence of other open charm molecules. In the meson-meson sector, two molecules near the mass thresholds of $D{D}^{\ast }$ and $D^{\ast }{D}^{\ast }$ with $I(J^P)=0(1^{+})$ are obtained, and using the heavy quark flavor symmetry their $\bar{B}{\bar{B}}^{\ast }$ and ${\bar{B}}^{\ast }{\bar{B}}^{\ast }$ counterparts are also predicted. In the meson-baryon sector, 7 open charm molecules with $I=1/2$ near the mass thresholds of $D^{(\ast )}{\Sigma }_c^{(\ast )}$ naturally appear, as dictated by the heavy quark spin symmetry.

    hep-phhep-exPRD(2020)·119 citations
23. 23*

    Producing fully-charm structures in the $J/\psi$-pair invariant mass spectrum

    Jun-Zhang Wang🇨🇳 · Dian-Yong Chen🇨🇳 · Xiang Liu🇨🇳 · Takayuki Matsuki🇯🇵

    Very recently, the LHCb Collaboration reported the observation of several enhancements in the invariant mass spectrum of a $J/\psi$ pair between 6.2 and 7.4 GeV. In this work, we propose the dynamical mechanism to mimic the experimental data of a di-$J/\psi$ mass spectrum given by LHCb, which is based on the reactions, where all the possible combinations of a double charmonium directly produced by a proton-proton collision are transferred into a final state $J/\psi J/\psi$. We find that the LHCb experimental data can be well reproduced. We further extend our framework to study a di-${\rm Y}(1S)$ system, and give the line shape of a differential cross section of a partner process in a $b\bar{b}$ system on the invariant mass of ${\rm Y}(1S){\rm Y}(1S)$, which shows that there should exist possible enhancements near $m_{{\rm Y}(1S){\rm Y}(1S)}=$19.0, 19.3, 19.7 GeV in the ${\rm Y}(1S)$-pair invariant mass spectrum. These predictions can be tested in LHCb and CMS, which can be as a potential research issue in near future.

    hep-phhep-exPRD(2021)·87 citations
24. 24*

    Central exclusive diffractive production of axial-vector $f_1(1285)$ and $f_1(1420)$ mesons in proton-proton collisions

    Piotr Lebiedowicz🇵🇱 · Josef Leutgeb🇦🇹 · Otto Nachtmann🇩🇪 · Anton Rebhan🇦🇹 · Antoni Szczurek🇵🇱

    We present a study of the central exclusive diffractive production of the $f_1(1285)$ and $f_1(1420)$ resonances in proton-proton collisions. The theoretical results are calculated within the tensor-pomeron approach. Two pomeron-pomeron-$f_1$ tensorial couplings labeled by $(l,S)=(2,2)$ and $(4,4)$ are derived. We adjust the model parameters (coupling constants, cutoff constant) to the WA102 experimental data taking into account absorption effects. Both the $(l,S)=(2,2)$ and $(4,4)$ couplings separately allow one to describe the WA102 differential distributions. We compare these predictions with those of the Sakai-Sugimoto model, where the pomeron-pomeron-$f_1$ couplings are determined by the mixed axial-gravitational anomaly of QCD. We derive an approximate relation between the pomeron-pomeron-$f_1$ coupling constants of this approach and the $(l,S)=(2,2)$ and $(4,4)$ couplings. Then we present our predictions for the energies available at the RHIC and LHC. The total cross sections and several differential distributions are presented. Analysis of the distributions in the azimuthal angle ${\varphi }_{pp}$ between the transverse momenta of the outgoing protons may be used to disentangle $f_1$- and $\eta$-type resonances contributing to the same final channel. We find for the $f_1(1285)$ a total cross section $\sim 38$ $\mu$b for $\sqrt{s}=13$ TeV and a rapidity cut on the $f_1$ of $|{\mathrm{y}}_{\mathrm{M}}|<2.5$. We predict a much larger cross section for production of $f_1(1285)$ than for production of $f_2(1270)$ in the ${\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ decay channel for the LHC energies. This opens a possibility to study the $f_1(1285)$ meson in experiments planned at the LHC.

    hep-phhep-exPRD(2020)·26 citations
25. 25*

    $X_0(2900)$ and $X_1(2900)$: hadronic molecules or compact tetraquarks

    Hua-Xing Chen🇨🇳 · Wei Chen🇨🇳 · Rui-Rui Dong🇨🇳 · Niu Su🇨🇳

    Very recently the LHCb Collaboration reported their observation of the first two fully open-flavor tetraquark states, the $X_0(2900)$ of $J^P=0^{+}$ and the $X_1(2900)$ of $J^P=1^{-}$. We study their possible interpretations using the method of QCD sum rules, paying special attention to an interesting feature of this experiment that the higher resonance $X_1(2900)$ has a width significantly larger than the lower one $X_0(2900)$. Our results suggest that the $X_0(2900)$ can be interpreted as the $S$-wave $D^{\ast -}{K}^{\ast +}$ molecule state of $J^P=0^{+}$, and the $X_1(2900)$ can be interpreted as the $P$-wave $\bar{c}\bar{s}ud$ compact tetraquark state of $J^P=1^{-}$. Mass predictions of their bottom partners are also given.

    hep-phChin.Phys.Lett.(2020)·106 citations
26. 26*

    TMD factorization for dijet and heavy-meson pair in DIS

    Rafael F. del Castillo🇪🇸 · Miguel G. Echevarria🇪🇸 · Yiannis Makris🇮🇹 · Ignazio Scimemi🇪🇸

    We study a transverse momentum dependent (TMD) factorization framework for the processes of di-jet and heavy meson pair production in deep-inelastic-scattering in an electron-proton collider, considering the measurement of the transverse momentum imbalance of the two hard probes in the Breit frame. For the factorization theorem we employ soft-collinear and boosted-heavy-quark effective field theories. The factorized cross-section for both processes is sensitive to gluon unpolarized and linearly polarized TMD distributions and requires the introduction of a new soft function. We calculate the new soft function here at one loop, regulating rapidity divergences with the $\delta$-regulator. In addition, using a factorization consistency relation and a universality argument regarding the heavy-quark jet function, we obtain the anomalous dimension of the new soft function at two loops.

    hep-phnucl-exnucl-thJHEP(2021)·48 citations
27. 27*

    R-parity Violation and Light Neutralinos at ANUBIS and MAPP

    Herbert K. Dreiner🇩🇪 · Julian Y. Günther🇩🇪 · Zeren Simon Wang🇹🇼

    In R-parity-violating supersymmetry the lightest neutralino can be very light, even massless. For masses in the range $500$ MeV$\lesssim m_{{\tilde{\chi }}_1^0}\lesssim 4.5$ GeV the neutralino can be produced in hadron collisions from rare meson decays via an R-parity violating coupling, and subsequently decay to a lighter meson and a charged lepton. Due to the small neutralino mass and for small R-parity violating coupling the lightest neutralino is long-lived, leading to displaced vertices at fixed-target and collider experiments. In this work, we study such signatures at the proposed experiments ANUBIS and MAPP at the LHC. We also compare their sensitivity reach in these scenarios with that of other present and proposed experiments at the LHC such as ATLAS, CODEX-b, and MATHUSLA. We find that ANUBIS and MAPP can show complementary or superior sensitivity.

    hep-phPRD(2021)·54 citations
28. 28*

    Bottom-Flavored Mono-Tau Tails at the LHC

    David Marzocca🇮🇹 · Ui Min🇰🇷 · Minho Son🇰🇷

    We study the effective field theory sensitivity of an LHC analysis for the $\tau \nu$ final state with an associated b-jet. To illustrate the improvement due to the b-tagging, we first recast the recent CMS analysis in the $\tau \nu$ channel, using an integrated luminosity of 35.9 fb${}^{-1}$ at $\sqrt{s}=13$ TeV, and provide limits on all the dimension-six effective operators which contribute to the process. The expected limits from the b-tagged analysis are then derived and compared. We find an improvement of approximately $\sim 30\%$ in the bounds for operators with a b quark. We also discuss in detail possible angular observables to be used as a discriminator between dimension-six operators with different Lorentz structure. Finally, we study the impact of these limits on some simplified scenarios aimed at addressing the observed deviations from the Standard Model in lepton flavor universality ratios of semileptonic B-meson decays. In particular, we compare the collider limits on those scenarios set by our analysis either with or without the b-tagging, assuming an integrated luminosity of 300 fb${}^{-1}$, with relevant low-energy flavor measurements.

    hep-phhep-exJHEP(2020)·56 citations
29. 29*

    Logarithmically enhanced Euler-Heisenberg Lagrangian contribution to the electron gyromagnetic factor

    Andrzej Czarnecki🇨🇦 · Jan Piclum🇩🇪 · Robert Szafron🇨🇭

    Contrary to what was previously believed, two-loop radiative corrections to the $g$-factor of an electron bound in a hydrogen-like ion at $\mathcal{O}\left({\alpha }^2(Z\alpha {)}^5\right)$ exhibit logarithmic enhancement. This previously unknown contribution is due to a long-distance light-by-light scattering amplitude. Taking an effective field theory approach, and using the Euler-Heisenberg Lagrangian, we find $\Delta g=-{\left(\frac{\alpha }{\pi }\right)}^2{\left(Z\alpha \right)}^5\frac{56\pi }{135}\ln Z\alpha$.

    hep-phphysics.atom-phPRA(2020)·14 citations
30. 30*

    Sum Rules in the Standard Model Effective Field Theory from Helicity Amplitudes

    Jiayin Gu🇩🇪 · Lian-Tao Wang🇺🇸

    The dispersion relation of an elastic 4-point amplitude in the forward direction leads to a sum rule that connects the low energy amplitude to the high energy observables. We perform a classification of these sum rules based on massless helicity amplitudes. With this classification, we are able to systematically write down the sum rules for the dimension-6 operators of the Standard Model Effective Field Theory (SMEFT), some of which are absent in previous literatures. These sum rules offer distinct insights on the relations between the operator coefficients in the EFT and the properties of the full theory that generates them. Their applicability goes beyond tree level, and in some cases can be used as a practical method of computing the one loop contributions to low energy observables. They also provide an interesting perspective for understanding the custodial symmetries of the SM Higgs and fermion sectors.

    hep-phhep-thJHEP(2021)·39 citations
31. 31*

    The magnetic moment of $P_c(4312)$ as a $\bar{D}{\Sigma }_c$ molecular state

    Yong-Jiang Xu🇨🇳 · Yong-Lu Liu🇨🇳 · Ming-Qiu Huang🇨🇳

    In this paper, we tentatively assign the $P_c(4312)$ to be a $\bar{D}{\Sigma }_c$ molecular state with quantum number $J^P={\frac{1}{2}}^{-}$, and calculate its magnetic moment using the QCD sum rule method in external weak electromagnetic field. Starting with the two-point correlation function in external electromagnetic field and expanding it in power of the electromagnetic interaction Hamiltonian, we extract the magnetic moment from the linear response to the external electromagnetic field. The numerical value of the magnetic moment of $P_c(4312)$ is ${\mu }_{P_c}=1.75_{-0.11}^{+0.15}$.

    hep-phEPJC(2021)·42 citations
32. 32*

    Incompatible coordinate algebra representations as the origin of particle generations

    Shane Farnsworth🇩🇪

    The success of the Higgs mechanism in the standard model has led to the speculation that the standard model gauge group might arise through an analogous breaking of a yet more unified group. Such `grand unified theories' have the advantage of unifying both the gauge structure and fermion representations of the standard model. Unfortunately, the theories that most elegantly unify the fermions, without predicting extra unobserved fermion states, do not explain the existence of the three fermion generations. They also typically predict a proliferation of bosonic states, which lead to so-far unobserved processes like proton decay. In this paper we introduce an alternative explanation for why one might only observe a subgroup of a larger `unified' group in nature. The approach we introduce gives rise naturally to a generation structure without the appearance of unwanted fermion states, and is cleaner in the sense that it avoids the usual proliferation of unobserved bosonic states and resulting unobserved processes.

    hep-phhep-th0 citations
33. 33*

    Discovery vs. Precision in Nuclear Physics- A Tale of Three Scales

    Gerald A. Miller🇺🇸

    At least three length scales are important in gaining a complete understanding of the physics of nuclei. These are the radius of the nucleus, the average inter-nucleon separation distance, and the size of the nucleon. The connections between the different scales are examined by using examples that demonstrate the direct connection between short-distance and high momentum transfer physics and also that significant high momentum content of wave functions is inevitable. The nuclear size is connected via the independent-pair approximation to the nucleon-nucleon separation distance, and this distance is connected via the concept of virtuality to the EMC effect. An explanation of the latter is presented in terms of light-front holographic wave functions of QCD. The net result is that the three scales are closely related, so that a narrow focus on any given specific range of scales may prevent an understanding of the fundamental origins of nuclear properties. It is also determined that, under certain suitable conditions, experiments are able to measure the momentum dependence of wave functions.

    ↳ nucl-thhep-phnucl-exPRC(2020)·9 citations
34. 34*

    Summary of Workshop on Common Neutrino Event Generator Tools

    Josh Barrow🇺🇸 · Minerba Betancourt🇺🇸 · Linda Cremonesi🇬🇧 · Steve Dytman🇺🇸 · Laura Fields🇺🇸 · Hugh Gallagher🇺🇸 · Steven Gardiner🇺🇸 · Walter Giele🇺🇸 · Robert Hatcher🇺🇸 · Joshua Isaacson🇺🇸 · Teppei Katori🇬🇧 · Pedro Machado🇺🇸 and 11 other authors

    A neutrino community workshop was held at Fermilab in Jan 2020, with the aim of developing an implementation plan for a set of common interfaces to Neutrino Event Generators. This white paper summarizes discussions at the workshop and the resulting plan.

    ↳ hep-exhep-ph10 citations
35. 35*

    Ab initio neutrinoless double-beta decay matrix elements for 48Ca, 76Ge, and 82Se

    A. Belley🇨🇦 · C. G. Payne🇨🇦 · S. R. Stroberg🇺🇸 · T. Miyagi🇨🇦 · J. D. Holt🇨🇦

    We calculate basis-space converged neutrinoless $\beta \beta$ decay nuclear matrix elements for the lightest candidates: 48Ca, 76Ge and 82Se. Starting from initial two- and three-nucleon forces, we apply the ab initio in-medium similarity renormalization group to construct valence-space Hamiltonians and consistently transformed $\beta \beta$-decay operators. We find that the tensor component is non-negligible in 76Ge and 82Se, and resulting nuclear matrix elements are overall 25-45% smaller than those obtained from the phenomenological shell model. While a final matrix element with uncertainties still requires substantial developments, this work nevertheless opens a path toward a true first-principles calculation of neutrinoless $\beta \beta$ decay in all nuclei relevant for ongoing large-scale searches.

    ↳ nucl-thhep-phnucl-exPRL(2021)·134 citations
36. 36*

    Humanly traversable wormholes

    Juan Maldacena🇺🇸 · Alexey Milekhin🇺🇸

    We point out that there can be humanly traversable wormhole solutions in some previously considered theories for physics beyond the Standard Model, namely the Randall-Sundrum model.

    ↳ hep-thgr-qchep-phPRD(2021)·116 citations
37. 37*

    Geometric Recursion from Polytope Triangulations and Twisted Homology

    Nikhil Kalyanapuram🇺🇸

    A geometric approach to understanding recursion relations for scattering amplitudes is developed. We achieve this by studying intersection numbers of triangulated accordiohedra presented as hyperplane arrangements. The cancellation of spurious divergences is subsequently realized as a topological no-boundary condition.

    ↳ hep-thhep-phmath-phmath.MPPRD(2020)·7 citations
38. 38*

    Stuckelberg SUSY QED and Infrared Problem

    Radhika Vinze🇮🇳 · T. R. Govindarajan🇮🇳 · Anuradha Misra🇮🇳 · P. Ramadevi🇮🇳

    We review gauge invariant $\mathcal{N}=1$ supersymmetric massive $U(1)$ gauge theory coupled to matter and Stuckelberg superfields. We focus on the leading order self energy and vertex correction to the matter field in the massless limit of both the $U(1)$ vector superfield and the Stuckelberg superfield. We explicitly verify that the theory is infrared divergence free in the massless limit. Hence the Stuckelberg mechanism appears to be the efficient route to handle infrared divergences seen in supersymmetric quantum electrodynamics.Since these additional particles have very small masses they can serve as dark matter candidates through `Ultralight particles' mechanism.

    ↳ hep-thhep-phMod.Phys.Lett.A(2020)·7 citations
39. 39*

    Dibaryons: Molecular versus Compact Hexaquarks

    H. Clement🇩🇪 · T. Skorodko🇩🇪

    Hexaquarks constitute a natural extension of complex quark systems like also tetra- and pentaquarks do. To this end the current status of $d^{\ast }(2380)$ in both experiment and theory is shortly reviewed. Recent high-precision measurements in the nucleon-nucleon channel and analyses thereof have established $d^{\ast }(2380)$ as an indisputable resonance in the long-sought dibaryon channel. Important features of this $I(J^P)=0(3^{+})$ state are its narrow width and its deep binding relative to the $\Delta (1232)\Delta (1232)$ threshold. Its decay branchings favor theoretical calculations predicting a compact hexaquark nature of this state. We review the current status of experimental and theoretical studies on $d^{\ast }(2380)$ as well as new physics aspects it may bring in the future. In addition, we review the situation at the $\Delta (1232)N$ and $N^{\ast }(1440)N$ thresholds, where evidence for a number of resonances of presumably molecular nature have been found -- similar to the situation in charmed and beauty sectors. Finally we briefly discuss the situation of dibaryon searches in the flavored quark sectors.

    ↳ nucl-thhep-exhep-phnucl-exCPC(2021)·28 citations
40. 40*

    Collective nuclear vibrations and initial state shape fluctuations in central Pb+Pb collisions: resolving the $v_2$ to $v_3$ puzzle

    B.G. Zakharov🇷🇺

    We have studied, for the first time, the influence of the collective quantum effects in the nuclear wave functions on the azimuthal anisotropy coefficients ${ϵ}_{2,3}$ in the central Pb+Pb collisions at the LHC energies. With the help of the energy weighted sum rule we demonstrate that the classical treatment with the Woods-Saxon nuclear density overestimates the mean square quadrupole moment of the ${}^{208}$Pb nucleus by a factor of $\sim 2.2$. The Monte-Carlo Glauber simulation of the central Pb+Pb collisions accounting for the restriction on the quadrupole moment leads to ${ϵ}_2/{ϵ}_3\approx 0.8$ which allows to resolve the $v_2$-to-$v_3$ puzzle.

    ↳ nucl-thhep-phJETP Lett.(2020)·10 citations
41. 41*

    The eclectic flavor symmetry of the ${\mathbb{Z}}_2$ orbifold

    Alexander Baur🇩🇪 · Moritz Kade🇩🇪 · Hans Peter Nilles🇩🇪 · Saul Ramos-Sanchez🇲🇽 · Patrick K.S. Vaudrevange🇩🇪

    Modular symmetries naturally combine with traditional flavor symmetries and $\mathcal{C}\mathcal{P}$, giving rise to the so-called eclectic flavor symmetry. We apply this scheme to the two-dimensional ${\mathbb{Z}}_2$ orbifold, which is equipped with two modular symmetries $\mathrm{SL}(2,\mathbb{Z}{)}_T$ and $\mathrm{SL}(2,\mathbb{Z}{)}_U$ associated with two moduli: the Kähler modulus $T$ and the complex structure modulus $U$. The resulting finite modular group is $((S_3\times S_3)⋊{\mathbb{Z}}_4)\times {\mathbb{Z}}_2$ including mirror symmetry (that exchanges $T$ and $U$) and a generalized $\mathcal{C}\mathcal{P}$-transformation. Together with the traditional flavor symmetry $(D_8\times D_8)/{\mathbb{Z}}_2$, this leads to a huge eclectic flavor group with 4608 elements. At specific regions in moduli space we observe enhanced unified flavor symmetries with as many as 1152 elements for the tetrahedral shaped orbifold and $⟨T⟩=⟨U⟩=\exp (\pi \mathrm{i}/3)$. This rich eclectic structure implies interesting (modular) flavor groups for particle physics models derived form string theory.

    ↳ hep-thhep-phJHEP(2021)·68 citations
42. 42*

    Conformal correlators as simplex integrals in momentum space

    Adam Bzowski🇬🇧 · Paul McFadden · Kostas Skenderis🇬🇧

    We find the general solution of the conformal Ward identities for scalar $n$-point functions in momentum space and in general dimension. The solution is given in terms of integrals over $(n-1)$-simplices in momentum space. The $n$ operators are inserted at the $n$ vertices of the simplex, and the momenta running between any two vertices of the simplex are the integration variables. The integrand involves an arbitrary function of momentum-space cross ratios constructed from the integration variables, while the external momenta enter only via momentum conservation at each vertex. Correlators where the function of cross ratios is a monomial exhibit a remarkable recursive structure where $n$-point functions are built in terms of $(n-1)$-point functions. To illustrate our discussion, we derive the simplex representation of $n$-point contact Witten diagrams in a holographic conformal field theory. This can be achieved through both a recursive method, as well as an approach based on the star-mesh transformation of electrical circuit theory. The resulting expression for the function of cross ratios involves $(n-2)$ integrations, which is an improvement (when $n>4$) relative to the Mellin representation that involves $n(n-3)/2$ integrations.

    ↳ hep-thcond-mat.str-elhep-phJHEP(2021)·76 citations
43. 43*

    Primordial black holes as dark matter and gravitational waves from bumpy axion inflation

    Ogan Özsoy🇵🇱 · Zygmunt Lalak🇵🇱

    We consider a mechanism for producing a significant population of primordial black holes (PBHs) and an observable stochastic gravitational wave background (SGWB) within string theory inspired models of inflation. In this framework where inflaton is identified as a non-compact axion-like field, sub-leading non-perturbative effects can superimpose steep cliffs connected by smooth plateaus onto the underlying axion potential. In the presence of coupling to Abelian gauge fields, the motion of axion on the cliff-like region(s) of its potential triggers a localized production of one helicity state of gauge fields due to the temporary fast-roll of axion around such a feature. In this setup, primordial fluctuations sourced by vector fields exhibit a localized peak in momentum space corresponding to modes that exit the horizon when the axion velocity is maximal. As an application of this general mechanism, we present an example of axion inflation which both matches Planck observations at CMB scales and generates a population of light PBHs ($M_{\mathrm{PBH}}\simeq 10^{-13}{M}_{\odot }$) that can account for all dark matter. In this scenario, the enhanced scalar fluctuations that leads to PBHs also generate an observable SGWB of induced origin at LISA scales. The amplitude and shape of the resulting GW signal inherits specific properties (such as non-Gaussianity and its shape) of its scalar sources that may allow us to distinguish this mechanism from other inflationary scenarios and astrophysical backgrounds. This GW signal together with an observation of PBH distribution at the corresponding scales can thus provide a window to the inflationary dynamics on scales much smaller than those probed by Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) Measurements.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2021)·97 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.