Wed·Mar 3, 2021Wednesday·March 3, 2021

1. 01*

   Long-lived bi$\mathbf{\nu }$o at the LHC

   Julia Gehrlein🇺🇸 · Seyda Ipek🇺🇸

   We examine the detection prospects for a long-lived bi$\nu$o, a pseudo-Dirac bino which is responsible for neutrino masses, at the LHC and at dedicated long-lived particle detectors. The bi$\nu$o arises in $U(1{)}_R$-symmetric supersymmetric models where the neutrino masses are generated through higher dimensional operators in an inverse seesaw mechanism. At the LHC the bi$\nu$o is produced through squark decays and it subsequently decays to quarks, charged leptons and missing energy via its mixing with the Standard Model neutrinos. We consider long-lived bi$\nu$os which escape the ATLAS or CMS detectors as missing energy and decay to charged leptons inside the proposed long-lived particle detectors FASER, CODEX-b, and MATHUSLA. We find the currently allowed region in the squark-bi$\nu$o mass parameter space by recasting most recent LHC searches for jets+MET. We also determine the reach of MATHUSLA, CODEX-b and FASER. We find that a large region of parameter space involving squark masses, bi$\nu$o mass and the messenger scale can be probed with MATHUSLA, ranging from bi$\nu$o masses of 10 GeV-2 TeV and messenger scales $10^{2-11}$ TeV for a range of squark masses.

   hep-phhep-exJHEP(2021)·9 citations
2. 02*

   An exact lower bound within a 331 model closing solution

   Mario W. Barela🇧🇷

   On this note we show how one specific proposal of solution to the problem of `closing' the well motivated 331 model to the Standard Model actually implies a lower bound for the otherwise theoretically free vacuum expectation value $v_{\chi }$.

   hep-ph2 citations
3. 03*

   Diffractive rho + lepton pair production at an electron-ion collider

   W. Cosyn🇺🇸 · B. Pire🇫🇷

   In high energy electron-ion colliders, a new way to probe nucleon structure becomes available through diffractive reactions, where the incident particle produces a very energetic almost forward particle. QCD describes these reactions as due to the exchange of a Pomeron which may be perturbatively described as a dressed two-gluon state, provided a hard scale allows the factorization of the amplitude in terms of two impact factors convoluted with a Pomeron propagator. We consider here a process where such a description allows to access hadronic structure in terms of the generalized parton distributions, namely the electroproduction of a forward $\rho$ meson and a timelike deeply virtual photon, separated by a large rapidity gap. We explore the dependence of the cross section on the kinematic variables and study the dependence on the non-perturbative inputs (generalized parton distributions, distribution amplitude). Our leading order studies show the cross section is mainly sensitive to the GPD model input, but the small size of the cross sections could prohibit straightforward analysis of this process at planned facilities.

   hep-phnucl-exnucl-thPRD(2021)·12 citations
4. 04*

   A model consistent with LQCD data on $\rho$-meson screening mass

   Masahiro Ishii🇯🇵 · Akihisa Miyahara🇯🇵 · Hiroaki Kouno🇯🇵 · Masanobu Yahiro🇯🇵

   Recently, state-of-art LQCD calculations were done for $\pi$-meson and $\rho$-meson screening mass, $M_{\pi }^{\mathrm{scr}}(T)$ and $M_{\rho }^{\mathrm{scr}}(T)$. We consider the two-flavor system, and focus on temperature dependence $T$ of $M_{\pi }^{\mathrm{scr}}(T)$ and $M_{\rho }^{\mathrm{scr}}(T)$. Our aim is to construct a model consistent with LQCD data on $M_{\rho }^{\mathrm{scr}}(T)$ and $M_{\pi }^{\mathrm{scr}}(T)$.

   hep-phhep-lat0 citations
5. 05*

   Deep Learning strategies for ProtoDUNE raw data denoising

   Marco Rossi🇨🇭 · Sofia Vallecorsa🇨🇭

   In this work, we investigate different machine learning-based strategies for denoising raw simulation data from the ProtoDUNE experiment. The ProtoDUNE detector is hosted by CERN and it aims to test and calibrate the technologies for DUNE, a forthcoming experiment in neutrino physics. The reconstruction workchain consists of converting digital detector signals into physical high-level quantities. We address the first step in reconstruction, namely raw data denoising, leveraging deep learning algorithms. We design two architectures based on graph neural networks, aiming to enhance the receptive field of basic convolutional neural networks. We benchmark this approach against traditional algorithms implemented by the DUNE collaboration. We test the capabilities of graph neural network hardware accelerator setups to speed up training and inference processes.

   hep-phcs.LGhep-exphysics.comp-ph+1Comput.Softw.Big Sci.(2022)·8 citations
6. 06*

   Probing the $R_{K^{(\ast )}}$ Anomaly at a Muon Collider

   Guo-yuan Huang🇩🇪 · Sudip Jana🇩🇪 · Farinaldo S. Queiroz🇧🇷 · Werner Rodejohann🇩🇪

   The LHCb measurements of the $\mu /e$ ratio in $B\to K\ell \ell$ decays $(R_{K^{}})$ indicate a deficit with respect to the Standard Model prediction, supporting earlier hints of lepton universality violation observed in the $R_{K^{(\ast )}}$ ratio. Possible explanations of these $B$-physics anomalies include heavy $Z^{\prime }$ bosons or scalar and vector leptoquarks mediating $b\to s{\mu }^{+}{\mu }^{-}$. We note that a muon collider can directly measure this process via ${\mu }^{+}{\mu }^{-}\to b\bar{s}$ and can shed light on the lepton non-universality scenario. Investigating currently discussed center-of-mass energies $\sqrt{s}=3$, 6 and 10 TeV, we show that the parameter space of $Z^{\prime }$ and leptoquark solutions to the $R_{K^{(\ast )}}$ anomalies can be mostly covered. Effective operators explaining the anomalies can be probed with the muon collider setup $\sqrt{s}=6\mathrm{TeV}$ and integrated luminosity $L=4\mathrm{a}{\mathrm{b}}^{-1}$.

   hep-phhep-exPRD(2022)·64 citations
7. 07*

   Non-thermal leptogenesis and UV freeze-in of dark matter: impact of inflationary reheating

   Basabendu Barman🇮🇳 · Debasish Borah🇮🇳 · Rishav Roshan🇮🇳

   We study a minimal scenario to realize non-thermal leptogenesis and UV freeze-in of a Standard Model (SM) gauge singlet fermionic dark matter (DM) simultaneously, with inflaton field playing a non-trivial role in their yields. The renormalizable interactions are restricted to the SM fields, two right handed neutrinos (RHN) and inflaton coupling exclusively to the RHNs, while the DM couples to both the SM and the RHNs only via operators of dimension $d>4$. Considering two separate cases of $d=\{5,6\}$, we show that for $d=5$, inflaton decay into RHNs followed by their subsequent decay into SM particles lead to both reheating as well as DM production from the SM bath. This requires a cut-off scale as large as $\Lambda \sim 10^{17}\mathrm{GeV}$ depending on the DM mass. On the other hand, for $d=6$, DM production happens directly from scattering of RHNs (for $\Lambda \gtrsim 10^{14}\mathrm{GeV}$) that results in a very non-trivial evolution of the DM yield. In both these cases, it is possible to explain the observed baryon asymmetry through successful non-thermal leptogenesis via the decay of the RHNs, together with the PLANCK observed relic density of the DM via pure UV freeze-in mechanism. Taking into account both instantaneous as well as non-instantaneous reheating separately, we constrain the parameter space of this minimal scenario from relevant phenomenological requirements including sub-eV scale active neutrino masses and their mixing.

   hep-phastro-ph.COPRD(2021)·53 citations
8. 08*

   $J/\psi$ polarization in high multiplicity $pp$ and $pA$ collisions: CGC+NRQCD approach

   Tomasz Stebel🇵🇱 · Kazuhiro Watanabe🇺🇸

   Quarkonium production mechanism in high multiplicity small collision systems has recently been pursued in the color-glass-condensate (CGC) effective theory combined with non-relativistic QCD (NRQCD) factorization, allowing to study initial state interactions. Quarkonium polarization, potentially measured in future experiments, would help elucidate the quarkonium production mechanism at high multiplicities. In this paper, we provide predictions on $J/\psi$ polarization parameters in high multiplicity proton-proton ($pp$) and proton-nucleus ($pA$) collisions within the CGC+NRQCD framework. Theoretical predictions are given for $J/\psi$ rapidity $2.5<y_{J/\psi }<4$, charged-particle multiplicity pseudorapidity $|{\eta }_{ch}|<1$ and energies $\sqrt{S}=13\mathrm{TeV}$ for $pp$, $\sqrt{S}=8.16\mathrm{TeV}$ for $pA$ collisions. Considering two leptonic frame choices (Collins - Soper and helicity) we find a weak polarization of $J/\psi$ that additionally decreases with growing event activities. No significant system size dependence between $pp$ and $pA$ collisions is obtained - this could be a new constraint to initial state interactions in small collision systems.

   hep-phnucl-thPRD(2021)·24 citations
9. 09*

   Estimation of Impact Parameter and Transverse Spherocity in heavy-ion collisions at the LHC energies using Machine Learning

   Neelkamal Mallick🇮🇳 · Sushanta Tripathy🇮🇹 · Aditya Nath Mishra🇭🇺 · Suman Deb🇮🇳 · Raghunath Sahoo🇮🇳

   Recently, machine learning (ML) techniques have led to a range of numerous developments in the field of nuclear and high-energy physics. In heavy-ion collisions, the impact parameter of a collision is one of the crucial observables which has a significant impact on the final state particle production. However, calculation of such a quantity is nearly impossible in experiments as the length scale ranges in the level of a few fermi. In this work, we implement the ML-based regression technique via Boosted Decision Tree (BDT) to obtain a prediction of impact parameter in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV using A Multi-Phase Transport (AMPT) model. In addition, we predict an event shape observable, transverse spherocity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 and 5.02 TeV using AMPT and PYTHIA8 based on Angantyr model. After a successful implementation in small collision systems, the use of transverse spherocity in heavy-ion collisions has potential to reveal new results from heavy-ion collisions where the production of a QGP medium is already established. We predict the centrality dependent spherocity distributions from the training of minimum bias simulated data and it was found that the predictions from BDT based ML technique match with true simulated data. In the absence of experimental measurements, we propose to implement Machine learning based regression technique to obtain transverse spherocity from the known final state observables in heavy-ion collisions.

   hep-phhep-exnucl-exnucl-thPRD(2021)·37 citations
10. 10*

    Heavy tetraquarks in the relativistic quark model

    R.N. Faustov🇷🇺 · V.O. Galkin🇷🇺 · E.M. Savchenko🇷🇺

    We give a review of the calculations of the masses of tetraquarks with two and four heavy quarks in the framework of the relativistic quark model based on the quasipotential approach and QCD. The diquark-antidiquark picture of heavy tetraquarks is used. The quasipotentials of the quark-quark and diquark-antidiquark interactions are constructed similarly to the previous consideration of mesons and baryons. Diquarks are considered in the colour triplet state. It is assumed that the diquark and antidiquark interact in the tetraquark as a whole and the internal structure of the diquarks is taken into account by the calculated form factor of the diquark-gluon interaction. All parameters of the model are kept fixed from our previous calculations of meson and baryon properties. A detailed comparison of the obtained predictions for heavy tetraquark masses with available experimental data is given. Many candidates for tetraquarks are found. It is argued that the structures in the di-$J/\psi$ mass spectrum observed recently by the LHCb Collaboration can be interpreted as $cc\bar{c}\bar{c}$ tetraquarks.

    hep-phhep-exUniverse(2021)·118 citations
11. 11*

    A closer look at the extraction of $|V_{ub}|$ from $B\to \pi l\nu$

    Aritra Biswas🇮🇳 · Soumitra Nandi🇮🇳 · Sunando Kumar Patra🇮🇳 · Ipsita Ray🇮🇳

    To extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $|V_{ub}|$, we have re-analyzed all the available inputs (data and theory) on the $B\to \pi l\nu$ decays including the newly available inputs on the form-factors from light cone sum rule (LCSR) approach. We have reproduced and compared the results with the procedure taken up by the Heavy Flavor Averaging Group (HFLAV), while commenting on the effect of outliers on the fits. After removing the outliers and creating a comparable group of data-sets, we mention a few scenarios in the extraction of $|V_{ub}|$. In all those scenarios, the extracted values of $|V_{ub}|$ are higher than that obtained by HFLAV. Our best results for $|V_{ub}{|}^{exc.}$ are $(3.88\pm 0.13)\times 10^{-3}$ and $(3.87\pm 0.13)\times 10^{-3}$ in frequentist and Bayesian approaches, respectively, which are consistent with that extracted from inclusive decays $|V_{ub}{|}^{inc}$ within $1\sigma$ confidence interval.

    hep-phhep-exhep-latJHEP(2021)·21 citations
12. 12*

    Extended Higgs sectors, effective field theory and Higgs phenomenology

    Anisha🇮🇳 · Upalaparna Banerjee🇮🇳 · Joydeep Chakrabortty🇮🇳 · Christoph Englert🇬🇧 · Michael Spannowsky🇬🇧

    We consider the phenomenological implications of charged scalar extensions of the SM Higgs sector in addition to EFT couplings of this new state to SM matter. We perform a detailed investigation of modifications of loop-induced decays of the 125 GeV Higgs boson, which receives corrections from the propagating charged scalars alongside one-loop EFT operator insertions and demonstrate that the interplay of $H\to \gamma \gamma$ and $H\to Z\gamma$ decays can be used to clarify the additional states phenomenology in case a discovery is made in the future. In parallel, EFT interactions of the charged Higgs can lead to a decreased sensitivity to the virtual presence of charged Higgs states, which can significantly weaken the constraints that are naively expected from the precisely measured $H\to \gamma \gamma$ branching ratio. Again $H\to Z\gamma$ measurements provide complementary sensitivity that can be exploited in the future.

    hep-phhep-exPRD(2021)·8 citations
13. 13*

    Constraints on Relic Magnetic Black Holes

    Melissa D. Diamond🇺🇸 · David E. Kaplan🇺🇸

    We present current direct and astrophysical limits on the cosmological abundance of black holes with extremal magnetic charge. Because they don't Hawking radiate, much lighter primordial black holes could exist today if they are extremal. The dominant constraints come from white dwarf destruction for intermediate masses, and intergalactic gas heating for heavier black holes. Extremal magnetic black holes may catalyze proton decay, and thus we derive robust limits -- independent of the catalysis cross section -- from the above as well as from white dwarf heating. We discuss other bounds such as those from neutron star heating, solar neutrino production, binary formation and annihilation into gamma rays, and magnetic field destruction. We note that stable magnetically charged black holes can assist in the formation of neutron star mass black holes.

    hep-phastro-ph.COJHEP(2022)·30 citations
14. 14*

    New physics and the tau polarization vector in $b\to c\tau {\bar{\nu }}_{\tau }$ decays

    N. Penalva🇪🇸 · E. Hernández🇪🇸 · J. Nieves🇪🇸

    For a general $H_b\to H_c\tau {\bar{\nu }}_{\tau }$ decay we analyze the role of the $\tau$ polarization vector ${\mathcal{P}}^{\mu }$ in the context of lepton flavor universality violation studies. We use a general phenomenological approach that includes, in addition to the Standard Model (SM) contribution, vector, axial, scalar, pseudoscalar and tensor new physics (NP) terms which strength is governed by, complex in general, Wilson coefficients. We show that both in the laboratory frame, where the initial hadron is at rest, and in the center of mass of the two final leptons, a $\vec{\mathcal{P}}$ component perpendicular to the plane defined by the three-momenta of the final hadron and the $\tau$ lepton is only possible for complex Wilson coefficients, being a clear signal for physics beyond the SM as well as time reversal (or CP-symmetry) violation. We make specific evaluations of the different polarization vector components for the ${\Lambda }_b\to {\Lambda }_c$, ${\bar{B}}_c\to {\eta }_c,J/\psi$ and $\bar{B}\to D^{(\ast )}$ semileptonic decays, and describe NP effects in the complete two-dimensional space associated with the independent kinematic variables on which the polarization vector depends. We find that the detailed study of ${\mathcal{P}}^{\mu }$ has great potential to discriminate between different NP scenarios for $0^{-}\to 0^{-}$ decays, but also for ${\Lambda }_b\to {\Lambda }_c$ transitions. For this latter reaction, we pay special attention to corrections to the SM predictions derived from complex Wilson coefficients contributions.

    hep-phJHEP(2021)·19 citations
15. 15*

    Searching for axionlike particles with low masses in $pPb$ and $PbPb$ collisions

    V. P. Goncalves🇧🇷 · D. E. Martins🇧🇷 · M. S. Rangel🇧🇷

    The production of axionlike particles (ALPs) with small masses in ultraperipheral $Pb-p$ and $Pb-Pb$ collisions at the LHC is investigated. The cross section and kinematical distributions associated to the diphoton final state produced in the $\gamma \gamma \to a\to \gamma \gamma$ subprocesses are estimated considering a realistic set of kinematical cuts. A detailed analysis of the backgrounds is performed and the expected sensitivity to the ALP production is derived. Our results demonstrate that a future experimental analysis of the exclusive diphoton production for the forward rapidities probed by the LHCb detector can improve the existing exclusion limits on the ALP - photon coupling in the mass range 2 GeV $\le m_a\le$ 5 GeV.

    hep-phhep-exnucl-exnucl-thEPJC(2021)·23 citations
16. 16*

    Opportunities of OO and $p$O collisions at the LHC

    Jasmine Brewer🇨🇭 · Aleksas Mazeliauskas🇨🇭 · Wilke van der Schee🇨🇭

    This is the summary document of the virtual workshop "Opportunities of OO and $p$O collisions at the LHC", which took place Feb 4-10, 2021. We briefly review the presented perspectives on the physics opportunities of oxygen--oxygen and proton--oxygen collisions. The full workshop program and the recordings are available at cern.ch/OppOatLHC.

    hep-phastro-ph.HEhep-exnucl-ex+1124 citations
17. 17*

    DRAKE: Dark matter Relic Abundance beyond Kinetic Equilibrium

    Tobias Binder🇯🇵 · Torsten Bringmann🇳🇴 · Michael Gustafsson🇩🇪 · Andrzej Hryczuk🇵🇱

    We introduce DRAKE, a numerical precision tool for predicting the dark matter relic abundance also in situations where the standard assumption of kinetic equilibrium during the freeze-out process may not be satisfied. DRAKE comes with a set of three dedicated Boltzmann equation solvers that implement, respectively, the traditionally adopted equation for the dark matter number density, fluid-like equations that couple the evolution of number density and velocity dispersion, and a full numerical evolution of the phase-space distribution. We review the general motivation for these approaches and, for illustration, highlight three concrete classes of models where kinetic and chemical decoupling are intertwined in a way that quantitatively impacts the relic density: i) dark matter annihilation via a narrow resonance, ii) Sommerfeld-enhanced annihilation and iii) `forbidden' annihilation to final states that are kinematically inaccessible at threshold. We discuss all these cases in some detail, demonstrating that the commonly adopted, traditional treatment can result in an estimate of the relic density that is wrong by up to an order of magnitude. The public release of DRAKE, along with several examples of how to calculate the relic density in concrete models, is provided at drake.hepforge.org

    hep-phastro-ph.COEPJC(2021)·86 citations
18. 18*

    On the scalar $\pi K$ form factor beyond the elastic region

    Leon von Detten🇩🇪 · Frederic Noël🇩🇪 · Christoph Hanhart🇩🇪 · Martin Hoferichter🇨🇭 · Bastian Kubis🇩🇪

    Pion-kaon ($\pi K$) pairs occur frequently as final states in heavy-particle decays. A consistent treatment of $\pi K$ scattering and production amplitudes over a wide energy range is therefore mandatory for multiple applications: in Standard Model tests; to describe crossed channels in the quest for exotic hadronic states; and for an improved spectroscopy of excited kaon resonances. In the elastic region, the phase shifts of $\pi K$ scattering in a given partial wave are related to the phases of the respective $\pi K$ form factors by Watson's theorem. Going beyond that, we here construct a representation of the scalar $\pi K$ form factor that includes inelastic effects via resonance exchange, while fulfilling all constraints from $\pi K$ scattering and maintaining the correct analytic structure. As a first application, we consider the decay $\tau \to K_S\pi {\nu }_{\tau }$, in particular, we study to which extent the $S$-wave $K_0^{\ast }(1430)$ and the $P$-wave $K^{\ast }(1410)$ resonances can be differentiated and provide an improved estimate of the $CP$ asymmetry produced by a tensor operator. Finally, we extract the pole parameters of the $K_0^{\ast }(1430)$ and $K_0^{\ast }(1950)$ resonances via Padé approximants, $\sqrt{s_{K_0^{\ast }(1430)}}=[1408(48)-i180(48)]$ MeV and $\sqrt{s_{K_0^{\ast }(1950)}}=[1863(12)-i136(20)]$ MeV, as well as the pole residues. A generalization of the method also allows us to formally define a branching fraction for $\tau \to K_0^{\ast }(1430){\nu }_{\tau }$ in terms of the corresponding residue, leading to the upper limit $\text{BR}(\tau \to K_0^{\ast }(1430){\nu }_{\tau })<1.6\times 10^{-4}$.

    hep-phhep-exnucl-thEPJC(2021)·30 citations
19. 19*

    X-Ray Shapes of Elliptical Galaxies and Implications for Self-Interacting Dark Matter

    Alex McDaniel🇺🇸 · Tesla Jeltema🇺🇸 · Stefano Profumo🇺🇸

    Several proposed models for dark matter posit the existence of self-interaction processes that can impact the shape of dark matter halos, making them more spherical than the ellipsoidal halos of collisionless dark matter. One method of probing the halo shapes, and thus the strength of the dark matter self-interaction, is by measuring the shape of the X-ray gas that traces the gravitational potential in relaxed elliptical galaxies. In this work we identify a sample of 11 relaxed, isolated elliptical galaxies and measure the ellipticity of the gravitating matter using X-ray images from the XMM-Newton and Chandra telescopes. We explore a variety of different mass configurations and find that the dark matter halos of these galaxies have ellipticities around $ϵ\approx 0.2-0.5$. While we find non-negligible scatter in the ellipticity distribution, our results are consistent with some degree of self-interaction at the scale of $\sigma /m\sim 1$ cm${}^2$/g, yet they also remain compatible with a cold dark matter scenario. We additionally demonstrate how our results can be used to directly constrain specific dark matter models and discuss implications for current and future simulations of self-interacting dark matter models.

    ↳ astro-ph.COastro-ph.GAastro-ph.HEhep-phJCAP(2021)·17 citations
20. 20*

    Sommerfeld-enhanced dark matter searches with dwarf spheroidal galaxies

    Shin'ichiro Ando🇳🇱 · Koji Ishiwata🇯🇵

    We study observable signals from dark matter that self-annihilates via the Sommerfeld effect in dwarf spheroidal galaxies (dSphs). Since the effect of the Sommerfeld enhancement depends on the velocity of dark matter, it is crucial to determine the profile of dSphs to compute the J-factor, i.e., the line-of-sight integral of density squared. In our study we use the prior distributions of the parameters for satellite density profiles in order to determine the J-factor, making most out of the recent developments in the N-body simulations and semi-analytical modeling for the structure formation. As concrete models, we analyze fermionic dark matter that annihilates via a light scalar and Wino dark matter in supersymmetric models. We find that, with the more realistic prior distributions that we adopt in this study, the J-factor of the most promising dSphs is decreased by a factor of a few, compared with earlier estimates based on non-informative priors. Nevertheless, the Cherenkov Telescope Array should be able to detect the thermal Wino dark matter by pointing it toward best classical or ultrafaint dSphs for 500 hours.

    ↳ astro-ph.COhep-phPRD(2021)·13 citations
21. 21*

    Reevaluating reactor antineutrino spectra with new measurements of the ratio between ${}^{235}$U and ${}^{239}$Pu $\beta$ spectra

    V. Kopeikin🇷🇺 · M. Skorokhvatov🇷🇺 · O. Titov🇷🇺

    We report a reanalysis of the reactor antineutrino energy spectra based on the new relative measurements of the ratio $R={}^e{S}_5{/}^e{S}_9$ between cumulative $\beta$ spectra from ${}^{235}$U and ${}^{239}$Pu, performed at a research reactor in National Research Centre Kurchatov Institute (KI). A discrepancy with the $\beta$ spectra measured at Institut Laue-Langevin (ILL) was observed, indicating a steady excess of the ILL ratio by the factor of $1.054\pm 0.002$. We find a value of the ratio between inverse beta decay cross section per fission for ${}^{235}$U and ${}^{239}$Pu: ${(}^5{\sigma }_f{/}^9{\sigma }_f{)}_{KI}=1.45\pm 0.03$, and then we reevaluate the converted antineutrino spectra for ${}^{235}$U and ${}^{238}$U. We conclude that the new predictions are consistent with the results of Daya Bay and STEREO experiments.

    ↳ nucl-exhep-phnucl-thPRD(2021)·121 citations
22. 22*

    Triangle singularity mechanism for the $pp\to {\pi }^{+}d$ fusion reaction

    Natsumi Ikeno🇯🇵 · Raquel Molina🇪🇸 · Eulogio Oset🇪🇸

    We develop a model for the $pp\to {\pi }^{+}d$ reaction based on the $pp\to \Delta (1232)N$ transition followed by $\Delta (1232)\to \pi N^{\prime }$ decay and posterior fusion of $N{N}^{\prime }$ to give the deuteron. We show that the triangle diagram depicting this process develops a triangle singularity leading to a large cross section of this reaction compared to ordinary fusion reactions. The results of the calculation also show that the process is largely dominated by the $pp$ system in $L=2,S=0$, which transfers $J=2$ to the final ${\pi }^{+}d$ system. This feature is shown to be well suited to provide $L=2,S=1$, $J^{\mathrm{tot}}=3$ for $np$ in the $np(I=0)\to {\pi }^{-}pp$ followed by $pp\to {\pi }^{+}d$ reaction, which has been proposed recently, as a means of describing the so far assumed dibaryon $d^{\ast }(2380)$ peak.

    ↳ nucl-thhep-phPRC(2021)·35 citations
23. 23*

    Forecasts on Interacting Dark Energy from 21-cm Angular Power Spectrum with BINGO and SKA observations

    Linfeng Xiao🇨🇳 · Andre A. Costa🇨🇳 · Bin Wang🇨🇳

    Neutral hydrogen (HI) intensity mapping is a promising technique to probe the large-scale structure of the Universe, improving our understanding on the late-time accelerated expansion. In this work, we first scrutinize how an alternative cosmology, interacting dark energy (IDE), can affect the 21-cm angular power spectrum relative to the concordance $\Lambda$CDM model. We re-derive the 21-cm brightness temperature fluctuation in the context of such interaction and uncover an extra new contribution. Then we estimate the noise level of three upcoming HI intensity mapping surveys, BINGO, SKA1-MID Band1 and Band2, respectively, and employ a Fisher matrix approach to forecast their constraints on the IDE model. We find that while $\text{Planck}$ 2018 maintains its dominion over early-Universe parameter constraints, BINGO and SKA1-MID Band2 put complementary bounding to the latest CMB measurements on dark energy equation of state $w$, the interacting strength ${\lambda }_i$ and the reduced Hubble constant $h$, and SKA1-MID Band1 even outperforms $\text{Planck}$ 2018 in these late-Universe parameter constraints. The expected minimum uncertainties are given by SKA1-MID Band1+$\text{Planck}$: $\sim 0.34\%$ on $w$, $\sim 0.22\%$ on $h$, $\sim 0.64\%$ on HI bias $b_{\mathrm{HI}}$, and an absolute uncertainty of about $3\times 10^{-4}$ ($7\times 10^{-4}$) on ${\lambda }_1$ (${\lambda }_2$). Moreover, we quantify the effects from systematics of the redshift bin number, redshift-space distortions, foreground residuals and uncertainties on the measured HI fraction, ${\Omega }_{\mathrm{HI}}(z)$. Our results indicate a bright prospect for HI intensity mapping surveys in constraining IDE, whether on their own or further by synergies with other measurements.

    ↳ astro-ph.COgr-qchep-phMNRAS(2021)·21 citations
24. 24*

    Reheating constraints on K-inflation

    Pooja Pareek🇮🇳 · Akhilesh Nautiyal🇮🇳

    In this work we revisit constraints on K-inflation with DBI kinetic term and power-law kinetic term from reheating. For DBI kinetic term we choose monomial potentials, $V\propto {\varphi }^n$ with $n=2/3,1,2$ and $4$, and natural inflaton potential, and for power-law kinetic term we choose quadratic, quartic and exponential potentials. The phase of reheating can be parameterized in terms of reheating temperature $T_{re}$, number of e-folds during reheating $N_{re}$ and effective equation of state during reheating $w_{re}$. These parameters can be related to the spectral index $n_s$ and other inflationary parameters depending on the choice of inflaton kinetic term and potential. By demanding that $w_{re}$ should have a finite range and $T_{re}$ should be above electroweak scale, one can obtain the bounds on $n_s$ that can provide bounds on tensor-to-scalar ratio $r$. We find, for K-inflation with DBI kinetic term and quadratic and quartic potentials, that the upper bound on $r$ for physically plausible value of $0\le w_{re}\le 0.25$ is slightly larger than the Planck-2018 and BICEP2/Keck array bound, and for $n=2/3$ and $1$, the reheating equation of state should be less than $0$ to satisfy Planck-2018 joint constraints on $n_s$ and $r$. However, natural inflation with DBI kinetic term is compatible with Planck-2018 bounds on $r$ and joint constraints on $n_s$ and $r$ for physically plausible range $0\le w_{re}\le 0.25$. The quadratic and quartic potential with power-law kinetic term are also compatible with Planck-2018 joint constraints on $n_s$ and $r$ for $0\le w_{re}\le 1$. However, for exponential potential with power-law kinetic term, the equation of state during reheating $w_{re}$ should be greater than $1$ for $r-n_s$ predictions to lie within $68\%$C.L. of joint constraints on $n_s$ and $r$ from Planck-2018 observations.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2021)·15 citations
25. 25*

    Does inhomogeneous big bang nucleosynthesis produce an inhomogeneous element distribution today?

    Robert J. Scherrer🇺🇸

    Inhomogeneous big bang nucleosynthesis (BBN) produces a spatially inhomogeneous distribution of element abundances at $T\sim 10^9$ K, but subsequent element diffusion will tend to erase these inhomogeneities. We calculate the cosmological comoving diffusion length for the BBN elements. This diffusion length is limited by atomic scattering and is therefore dominated by diffusion when the atoms are neutral, between the redshifts of recombination and reionization. We find that the comoving diffusion length today is $d_{com}\approx 70$ pc for all of the elements of interest except ${}^7$Li, for which $d_{com}$ is an order of magnitude smaller because ${}^7$Li remains ionized throughout the relevant epoch. This comoving diffusion length corresponds to a substellar baryonic mass scale and is roughly equal to the horizon scale at BBN. These results lend support to the possibility that inhomogeneities on scales larger than the horizon at BBN could lead to a spatially inhomogeneous distribution of elements today, while purely subhorizon fluctuations at BBN can result only in a homogeneous element distribution at present.

    ↳ astro-ph.COgr-qchep-phPRD(2021)·4 citations
26. 26*

    Mapping topology to nuclear dilaton-HLS effective field theory for dense baryonic matter

    Yong-Liang Ma🇨🇳 · Mannque Rho🇫🇷

    We describe the on-going effort to formulate the baryon-quark continuity in terms of a topology change in the equation of state (EoS) of dense baryonic matter in analogy to -- and inspired by -- the mapping of the characteristics of Chern-Simon topological field theory to Kohn-Sham density functional theory in the fractional quantized Hall effect (FQHE). This is done by translating the density-dependent characteristics of the skyrmion-half-skyrmion transition formulated in the presence of hidden local symmetry and (hidden) scale symmetry to the density-dependent parameters of a renormalization-group approach to Fermi-liquid fixed point theory. Predictions made in finite nuclei and infinite compact-star matter are presented.

    ↳ nucl-thhep-ph3 citations
27. 27*

    Mirror Neutron Stars

    Maurício Hippert🇺🇸 · Jack Setford🇨🇦 · Hung Tan🇺🇸 · David Curtin🇨🇦 · Jacquelyn Noronha-Hostler🇺🇸 · Nicolas Yunes🇺🇸

    The fundamental nature of dark matter is entirely unknown. A compelling candidate is Twin Higgs mirror matter, invisible hidden-sector cousins of the Standard Model particles and forces. This predicts mirror neutron stars made entirely of mirror nuclear matter. We find their structure using realistic equations of state, robustly modified based on first-principle quantum chromodynamic calculations, for the first time. This allows us to predict their gravitational wave signals, demonstrating an impressive discovery potential and ability to probe dark sectors connected to the hierarchy problem.

    ↳ astro-ph.HEgr-qchep-phnucl-thPRD(2022)·78 citations
28. 28*

    Photon polarization tensor in a magnetized plasma: Absorptive part

    Xinyang Wang🇨🇳 · Igor Shovkovy🇺🇸

    We calculate the absorptive part of the photon polarization tensor in a hot magnetized relativistic plasma. In the derivation, we utilize a Landau-level representation for the fermion Green's function in a mixed coordinate-momentum space and obtain a closed-form expression for the one-loop polarization tensor. At the leading order in the coupling, its absorptive part is determined by particle and antiparticle splitting processes ($e^{-}\leftrightarrow e^{-}+\gamma$ and $e^{+}\leftrightarrow e^{+}+\gamma$, respectively), as well as by particle-antiparticle annihilation processes ($e^{-}+e^{+}\leftrightarrow \gamma$). The interpretation in terms of quantum transitions between Landau levels is also given. By making use of the photon polarization tensor, we study the differential photon emission rate in the quantum limit of magnetized relativistic plasma. At low energies, the photon emission has a prolate profile with the symmetry axis along the line of the magnetic field. At high energies, on the other hand, the photon emission has an oblate profile. The underlying reasons for such emission profiles are given in both regimes. The general result for the photon polarization tensor is also used to calculate the longitudinal and transverse components of magneto-optical conductivity.

    ↳ nucl-thhep-phhep-thPRD(2021)·40 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.