Tue·Aug 27, 2019Tuesday·August 27, 2019

1. 01*

   Vector-like quarks with non-renormalizable interactions

   Juan Carlos Criado🇪🇸 · Manuel Perez-Victoria🇪🇸

   We study the impact of the leading non-renormalizable terms in the effective field theory that describes general extensions of the Standard Model with vector-like quarks. Dropping the usual assumption of renormalizability has several phenomenological consequences for the production and decay of the heavy quarks and also for Higgs physics. The most dramatic effects, including those associated with a long lifetime, occur for vector-like quarks with non-standard quantum numbers.

   hep-phJHEP(2020)·20 citations
2. 02*

   Helicity amplitudes in the $\bar{B}\to D^{\ast }{\bar{\nu }}_{\tau }\tau$ decay with $V-A$ breaking in the quark sector

   L. R. Dai🇨🇳 · E. Oset🇪🇸

   In view of the recent measurement of the $F_L^{D^{\ast }}$ magnitude in the $\bar{B}\to D^{\ast }{\bar{\nu }}_{\tau }\tau$ reaction we evaluate this magnitude within the standard model and for a family of models with the ${\gamma }^{\mu }-\alpha {\gamma }^{\mu }{\gamma }_5$ current structure for the quarks for different values of $\alpha$. At the same time we evaluate also the transverse contributions, $M=-1$, $M=+1$, and find that the difference between the $M=-1$ and $M=+1$ contributions is far more sensitive to changes in $\alpha$ than the longitudinal component.

   hep-phEPJA(2020)·1 citation
3. 03*

   Exploring BSM Higgs couplings in single top-quark production

   Manfred Kraus🇩🇪 · Till Martini🇩🇪 · Sascha Peitzsch🇩🇪 · Peter Uwer🇩🇪

   In this article we study a Standard Model extension modifying the top-quark Yukawa coupling to the Higgs boson by allowing a mixture of CP-odd and -even couplings. Single top-quark production in association with an additional Higgs boson provides a natural laboratory to search for such extensions. However, because of the small cross section the experimental analysis is challenging. Already the measurement of the cross section for this process is highly non-trivial. Furthermore, using only cross section measurements, a certain parameter region would escape detection. Using an explicit BSM scenario we show that employing the Matrix Element Method a precise measurement becomes feasible. Ignoring signal detection efficiencies an integrated luminosity of about 20 fb^-1 would allow a discovery. Assuming signal detection efficiencies at the level of a few percent a potential signal could be established in the high luminosity phase of the LHC.

   hep-phhep-ex27 citations
4. 04*

   The Effect of Extended Cornell Potential on Heavy and Heavy-Light Meson Masses Using Series Method

   M. Abu-shady🇪🇬 · H. M. Fath-Allah🇪🇬

   The effect of an extended Cornell potential on mass spectra of heavy and heavy-light mesons is studied. The Cornell potential is extended to include quadratic potential and inverse quadratic potential. The N-radial Schrodinger equation is solved by using series method. The results for charmonium and bottomonium, and light-heavy meson masses are obtained. A comparison with other recent works is discussed. The present results are improved in comparison with other recent works and are in good agreement with experimental data.

   hep-ph4 citations
5. 05*

   To be, or not to be finite? The Higgs potential in Gauge-Higgs Unification

   Junji Hisano🇯🇵 · Yutaro Shoji🇯🇵 · Atsuyuki Yamada🇯🇵

   In this paper, we investigate the finiteness of the Higgs effective potential in an $\mathrm{SU}(\mathcal{N})$ Gauge-Higgs Unification (GHU) model defined on ${\mathbf{M}}^4\times S^1$. We obtain the Higgs effective potential at the two-loop level and find that it is finite. We also discuss that the Higgs effective potential is generically divergent for three- or higher-loop levels. As an example, we consider an $\mathrm{SU}(\mathcal{N})$ gauge theory on ${\mathbf{M}}^5\times S^1$, where the one-loop corrections to the four-Fermi operators are divergent. We find that the Higgs effective potential depends on their counter terms at the three-loop level.

   hep-phJHEP(2020)·12 citations
6. 06*

   Analysis of pseudoscalar and scalar $D$ mesons and charmonium decay width in hot magnetized asymmetric nuclear matter

   Rajesh Kumar🇮🇳 · Arvind Kumar🇮🇳

   In this article, we calculate the mass shift and decay constant of isospin averaged pseudoscalar ($D^{+}$,$D^0$) and scalar ($D_0^{+}$,$D_0^0$) mesons by the magnetic field induced quark and gluon condensates at finite density and temperature of asymmetric nuclear matter. We have calculated the in-medium chiral condensates from the chiral SU(3) mean field model and subsequently used these condensates in QCD Sum Rules (QCDSR) to calculate the effective mass and decay constant of $D$ mesons. Consideration of external magnetic field effects in hot and dense nuclear matter lead to appreciable modification in the masses and decay constants of $D$ mesons. Furthermore, we also studied the effective decay width of higher charmonium states ($\psi (3686),\psi (3770),{{\chi }_c}_0(3414),{{\chi }_c}_2(3556)$) as a by-product by using ${}^3{P}_0$ model which can have an important impact on the yield of $J/\psi$ mesons. The results of present work will be helpful to understand the experimental observables of the heavy ion colliders which aim to produce matter at finite density and moderate temperature.

   hep-phPRC(2020)·28 citations
7. 07*

   Scalar dark matter, Neutrino mass and Leptogenesis in a $\mathrm{U}(1{)}_{\mathrm{B}-\mathrm{L}}$ model

   Subhasmita Mishra🇮🇳 · Shivaramakrishna Singirala🇮🇳 · Suchismita Sahoo🇮🇳

   We investigate the phenomenology of singlet scalar dark matter in a simple $\mathrm{U}(1{)}_{\mathrm{B}-\mathrm{L}}$ gauge extension of standard model, made anomaly free with four exotic fermions. The enriched scalar sector and the new gauge boson $Z^{\prime }$, associated with $\mathrm{U}(1)$ gauge extension, connect the dark sector to the visible sector. We compute relic density, consistent with Planck limit and $Z^{\prime }$ mediated dark matter-nucleon cross section, compatible with PandaX bound. The mass of $Z^{\prime }$ and the corresponding gauge coupling are constrained from LEP-II and LHC dilepton searches. We also briefly scrutinize the tree level neutrino mass with dimension five operator. Furthermore, resonant leptogenesis phenomena is discussed with TeV scale exotic fermions to produce the observed baryon asymmetry of the Universe. Further, we briefly explain the impact of flavor in leptogenesis and we also project the combined constraints on Yukawa, consistent with oscillation data and observed baryon asymmetry. Additionally, we restrict the new gauge parameters by using the existing data on branching ratios of rare $B(\tau )$ decay modes. We see that the constraints from dark sector are much more stringent from flavor sector.

   hep-phJ.Phys.G(2021)·6 citations
8. 08*

   Electroweak Corrections to Dark Matter Direct Detection in a Vector Dark Matter Model

   S. Glaus🇩🇪 · M. Mühlleitner🇩🇪 · J. Müller🇩🇪 · S. Patel🇩🇪 · R. Santos🇵🇹

   Although many astrophysical and cosmological observations point towards the existence of Dark Matter (DM), the nature of the DM particle has not been clarified to date. In this paper, we investigate a minimal model with a vector DM (VDM) candidate. Within this model, we compute the cross section for the scattering of the VDM particle with a nucleon. We provide the next-to-leading order (NLO) cross section for the direct detection of the DM particle. Subsequently, we study the phenomenological implications of the NLO corrections, in particular with respect to the sensitivity of the direct detection DM experiments. We further investigate more theoretical questions such as the gauge dependence of the results and the remaining theoretical uncertainties due to the applied approximations.

   hep-phJHEP(2019)·26 citations
9. 09*

   Inelastic extra $U(1)$ charged scalar dark matter

   Nobuchika Okada🇺🇸 · Osamu Seto🇯🇵

   The null results in dark matter direct detection experiments imply the present scalar dark matter (DM) annihilation cross section to bottom quark pairs through the Higgs boson exchange is smaller than about $10^{-31}$ cm${}^3/$s for a wide DM mass range, which is much smaller than the required annihilation cross section for thermal relic DM. We propose models of a thermal relic DM with the present annihilation cross section being very suppressed. This property can be realized in an extra $U(1)$ gauge interacting complex scalar DM, where the thermal DM abundance is determined by coannihilation through the gauge interaction while the present annihilation is governed by Higgs bosons exchange processes. An interaction between DM and the extra $U(1)$ breaking Higgs field generates a small mass splitting between DM and its coannihilating partner so that coannihilation becomes possible and also the $Z^{\prime }$-mediated scattering off with a nucleon in direct DM search becomes inelastic. We consider scalar dark matter in $U(1{)}_{B-L},U(1{)}_{(B-L{)}_3}$ and $U(1{)}_{L_{\mu }-L_{\tau }}$ extended models and identify viable parameter regions. We also discuss various implications to future DM detection experiments, the DM interpretation of the gamma-ray excess in the globular cluster 47 Tucanae, the muon anomalous magnetic moment, the Hubble tension and others.

   hep-phastro-ph.COPRD(2020)·50 citations
10. 10*

    The number of sufficient and necessary conditions for CP conservation with Majorana neutrinos: three or four?

    Bingrong Yu🇨🇳 · Shun Zhou🇨🇳

    As is well-known, there exist totally three CP-violating phases in the leptonic sector if three ordinary neutrinos are massive Majorana particles. In this short note, we raise the question whether the number of sufficient and necessary conditions for CP conservation in the leptonic sector with massive Majorana neutrinos is three or four. An intuitive answer to this question would be three, which is also the total number of independent CP-violating phases. However, we give a counter example, in which three conditions are in general not sufficient for CP conservation. Only for all the lepton masses and mixing angles within their experimentally allowed ranges can we demonstrate that it is possible to find out three weak-basis invariants, which should be vanishing to guarantee leptonic CP conservation.

    hep-phPLB(2020)·20 citations
11. 11*

    Real and Complex Fundamental Partial Compositeness

    Alessandro Agugliaro🇩🇰 · Francesco Sannino🇩🇰

    We complete the analysis of the effective field theory at the electroweak scale for minimal models of fundamental partial compositeness. Specifically, we consider fermions in the complex and real representation of the gauge group underlying the composite Higgs dynamics, since the pseudo real representation was investigated earlier. The minimal models feature the cosets SU(4)xSU(4)/SU(4)_D and SU(5)/SO(5) respectively for the complex and real representations. We determine the vacuum alignment, the electroweak precision constraints, additional collider constraints. We finally discuss the main differences among the different models of minimal partial compositeness.

    hep-phJHEP(2020)·12 citations
12. 12*

    A cosmologically viable eV sterile neutrino model

    C. A. de S. Pires🇧🇷

    The MiniBooNE collaboration recently released a report claiming have observed an excess of electron and anti-electron neutrino with significance of $4.8\sigma$ C.L. corroborating, in this way, the long-standing LSND anomaly. Combined LSND and MiniBooNE analysis reach a significance of $6.0\sigma$ C.L. Such a result, if confirmed by future experiments, will cause considerable impact on particle physics since that such anomalies, when interpreted in terms of neutrino oscillation, require the existence of at least one light sterile neutrino. It happens that, on according to standard scenarios, such light sterile neutrino is incompatible with current cosmological data. In this way, understand these anomalies require an extension of the standard model capable of generating tiny masses for both active and sterile neutrinos and re-conciliates such a result with cosmology. An interesting proposal in this direction involve the existence of a secret sector interacting exclusively with sterile neutrinos. In this work we implement the canonical seesaw mechanism into the standard model in such a way that generates tiny masses to the active and sterile neutrinos and embody a secret sector capable of re-conciliating eV sterile neutrinos with cosmology. As other gains, the scalar content required by the implementation of the mechanism provides contribution to rare lepton decays, may accommodate the $g-2$ of the muon and poses a scalar singlet that may drive inflation through Higgs inflation mechanism without problem with loss of unitarity.

    hep-phPLB(2020)·4 citations
13. 13*

    Continuity from neutron matter to two-flavor quark matter with ${}^1{S}_0$ and ${}^3{P}_2$ superfluidity

    Yuki Fujimoto🇯🇵 · Kenji Fukushima🇯🇵 · Wolfram Weise🇩🇪

    This study is performed with the aim of gaining insights into the possible applicability of the quark-hadron continuity concept, not only in the idealized case of three-flavor symmetric quark matter, but also for the transition from neutron matter to two-flavor quark matter. A key issue is the continuity between neutron superfluidity and a corresponding superfluid quark phase produced by $d$-quark pairing. Symmetry arguments are developed and relevant dynamical mechanisms are analyzed. It is pointed out that the ${}^3{P}_2$ superfluidity in dense neutron matter has a direct analogue in the ${}^3{P}_2$ pairing of $d$-quarks in two-flavor quark matter. This observation supports the idea that the quark-hadron continuity hypothesis may be valid for such systems. Possible implications for neutron stars are briefly discussed.

    hep-phnucl-thPRD(2020)·33 citations
14. 14*

    Natural neutrino sector in a 331-model with Froggatt-Nielsen mechanism

    Katri Huitu🇫🇮 · Niko Koivunen🇫🇮 · Timo J. Kärkkäinen🇫🇮

    The extensions of the Standard Model based on the $SU(3{)}_c\times SU(3{)}_L\times U(1{)}_X$ gauge group (331-models) have been advocated to explain the number of fermion families in nature. It has been recently shown that the Froggatt-Nielsen mechanism, a popular way to explain the mass hierarchy of the charged fermions, can be incorporated into the 331-setting in an economical fashion (FN331). In this work we extend the FN331-model to include three right-handed neutrino singlets. We show that the seesaw mechanism is realized in this model. The scale of the seesaw mechanism is near the $SU(3{)}_L\times U(1{)}_X$-breaking scale. The model we present here simultaneously explains the mass hierarchy of all the fermions, including neutrinos, and the number of families.

    hep-phJHEP(2020)·7 citations
15. 15*

    Theory determination of $\bar{B}\to D^{(\ast )}{\ell }^{-}\bar{\nu }$ form factors at $\mathcal{O}(1/m_c^2)$

    Marzia Bordone🇩🇪 · Martin Jung🇮🇹 · Danny van Dyk🇩🇪

    We carry out an analysis of the full set of ten $\bar{B}\to D^{(\ast )}$ form factors within the framework of the Heavy-Quark Expansion (HQE) to order $\mathcal{O}({\alpha }_s,1/m_b,1/m_c^2)$, both with and without the use of experimental data. This becomes possible due to a recent calculation of these form factors at and beyond the maximal physical recoil using QCD light-cone sum rules, in combination with constraints from lattice QCD, QCD three-point sum rules and unitarity. We find good agreement amongst the various theoretical results, as well as between the theoretical results and the kinematical distributions in $\bar{B}\to D^{(\ast )}\{e^{-},{\mu }^{-}\}\bar{\nu }$ measurements. The coefficients entering at the $1/m_c^2$ level are found to be of $\mathcal{O}(1)$, indicating convergence of the HQE. The phenomenological implications of our study include an updated exclusive determination of $|V_{cb}|$ in the HQE, which is compatible with both the exclusive determination using the BGL parametrization and with the inclusive determination. We also revisit predictions for the lepton-flavour universality ratios $R_{D^{(\ast )}}$, the $\tau$ polarization observables $P_{\tau }^{D^{(\ast )}}$, and the longitudinal polarization fraction $F_L$. Posterior samples for the HQE parameters are provided as ancillary files, allowing for their use in subsequent studies.

    hep-phhep-exEPJC(2020)·186 citations
16. 16*

    Light charged Higgs boson production at future $ep$ colliders

    O. Flores-Sánchez🇲🇽 · J. Hernández-Sánchez🇲🇽 · C.G. Honorato🇲🇽 · S. Moretti🇬🇧 · S. Rosado-Navarro🇲🇽

    We present a recent study of light charged Higgs boson ($H^{-}$) production at the Large Hadron electron Collider (LHeC). We study the charged current production process $e^{-}p\to {\nu }_{e}q{H}^{-}$, taking in account the decay channels $H^{-}\to b\bar{c}$ and $H^{-}\to \tau {\bar{\nu }}_{\tau }$. We analyse the process in the framework of the 2-Higgs Doublet Model Type-III (2HDM-III), assuming a four-zero texture in the Yukawa matrices and a general Higgs potential. We consider a variety of both reducible and irreducible backgrounds for the signals of the $H^{-}$ state. We show that the detection of a light charged Higgs boson is feasible, assuming for the LHeC standard energy and luminosity conditions.

    hep-phPoS(2019)·4 citations
17. 17*

    Electric and magnetic axion quark nuggets, their stability and their detection

    O. Santillan🇦🇷 · M. Sempe🇦🇷

    The present work studies the dynamics of axion quark nuggets introduced in \cite{zhitnitsky} and exploited in the works \cite{zhitnitsky2}-\cite{zhitnitsky13}. The new feature considered here is the possibility that these nuggets become ferromagnetic. This possibility was pointed out in \cite{tatsumi}, although ferromagnetism may also take place due some anomaly terms found in \cite{son}-\cite{son2}. The purpose of the present letter however, is not to give evidence in favor or against these statements. Instead, it is focused in some direct consequences of this ferromagnetic behavior, if it exists. The first is that the nugget magnetic field induces an electric field due to the axion wall, which may induce pair production by Schwinger effect. Depending on the value of the magnetic field, the pair production can be quite large. A critical value for such magnetic field at the surface of the nugget is obtained, and it is argued that the value of the magnetic field of \cite{tatsumi} is at the verge of stability and may induce large pair production. The consequences of this enhanced pair production may be unclear. It may indicate that the the nugget evaporates, but on the other hand it may be just an indication that the intrinsic magnetic field disappears and the nuggets evolves to a non magnetized state such as \cite{zhitnitsky}-\cite{zhitnitsky13}. The interaction of such magnetic and electric nugget with the troposphere of the earth is also analyzed. However, if the magnetic field does not decay before the actual universe, then this would lead to high energy electron flux due to its interaction with the electron gases of the Milky Way. This suggests that these magnetized quarks may be a considerably part of dark matter, but only if their hypothetical magnetic and electric fields are evaporated.

    hep-phastro-ph.HEEPJC(2020)·2 citations
18. 18*

    Sensitivity of Lepton Number Violating Meson Decays in Different Experiments

    Eung Jin Chun🇰🇷 · Arindam Das🇯🇵 · Sanjoy Mandal🇮🇳 · Manimala Mitra🇮🇳 · Nita Sinha🇮🇳

    We study the discovery prospect of different three body lepton number violating~(LNV) meson decays $M_1^{-}\to {\ell }_1^{-}{\ell }_2^{-}{M}_2^{+}$ in the framework of right handed~(RH) neutrino extended Standard Model~(SM). We consider a number of ongoing experiments, such as, NA62 and LHCb at CERN, Belle II at SuperKEK, as well as at the proposed future experiments, SHiP, MATHUSLA and FCC-ee. The RH Majorana neutrino $N$ mediating these meson decays provides a resonant enhancement of the rates, if the mass of $N$ lies in the range $(100\text{MeV}-6\text{GeV})$. We consider the effect of parent mesons velocity, as well as, the effect of finite detector size. Using the expected upper limits on the number of events for the LNV decay modes, $M_1^{-}\to {\ell }_1^{-}{\ell }_2^{-}{\pi }^{+}$~($M_1=B,B_c,D,D_s\text{and}K$), we analyze the sensitivity reach of the mixing angles $|V_{eN}{|}^2$, $|V_{\mu N}{|}^2$, $|V_{\tau N}{|}^2$, $|V_{eN}{V}_{\mu N}|$, $|V_{eN}{V}_{\tau N}|$ and $|V_{\mu N}{V}_{\tau N}|$ as a function of heavy neutrino mass $M_N$. We show that, inclusion of parent meson velocity can account to a large difference for active-sterile mixing, specially for $D$, $D_s$ meson decay at SHiP and $K$ meson decay at NA62. Taking into account the velocity of the $D_s$ meson, the future beam dump experiment SHiP can probe $|V_{eN}{|}^2\sim 10^{-9}$. For RH neutrino mass in between 2 - 5 GeV, MATHUSLA can provide best sensitivity reach of active-sterile mixings.

    hep-phhep-exPRD(2019)·73 citations
19. 19*

    Electroweak Breaking and Higgs Boson Profile in the Simplest Linear Seesaw Model

    Duarte Fontes🇵🇹 · Jorge C. Romao🇵🇹 · Jose W. F. Valle🇪🇸

    We examine the simplest realization of the linear seesaw mechanism within the Standard Model gauge structure. Besides the standard scalar doublet, there are two lepton-number-carrying scalars, a nearly inert SU2 doublet and a singlet. Neutrino masses result from the spontaneous violation of lepton number, implying the existence of a Nambu-Goldstone boson. Such "majoron" would be copiously produced in stars, leading to stringent astrophysical constraints. We study the profile of the Higgs bosons in this model, including their effective couplings to the vector bosons and their invisible decay branching ratios. A consistent electroweak symmetry breaking pattern emerges with a compressed spectrum of scalars in which the "Standard Model" Higgs boson can have a sizeable invisible decay into the invisible majorons.

    hep-phJHEP(2019)·19 citations
20. 20*

    Probing the high energy spectrum of neutral pions in ultra-high energy proton-Air interactions

    Lorenzo Cazon🇵🇹 · Ruben Conceição🇵🇹 · Miguel Martins🇵🇹 · Felix Riehn🇵🇹

    The interaction of ultra-high energy cosmic rays with the atmosphere nuclei has long been seen as a unique opportunity to study hadronic interactions above energies attainable by accelerators. However, so far the multiparticle production properties of the first interaction have been difficult to assess as they are masked by the many interactions that outline the shower development. In this work, we demonstrate, that relevant properties of the ultra-high energy first interaction can be accessed through the analysis of the shower-to-shower distribution of muons arriving at the ground. In particular, it is shown that the slope of the low-tail of the number of muon distribution measured at the ground is a direct link to the high energy spectrum of neutral pions produced in the interaction of the primary protons. In this presentation, it will also address the experimental feasibility of such measurements and their connection with physical quantities being currently measured at the Large Hadron Collider.

    hep-phhep-exPoS(2020)·4 citations
21. 21*

    Constraints on New Physics from $B$ mesons

    Monika Blanke🇩🇪

    These proceedings review the status of New Physics contributions to flavour violating $B$ decays. The anomalies in charged and neutral current $B$ decays related to lepton flavour universality violation have received a substantial amount of attention over the past years, and we discuss the current status in light of the new data presented earlier this year. We also recall a tension in the neutral $B$ meson mixing observables $\Delta M_d$ and $\Delta M_s$ and in particular their ratio, when compared with their SM predictions obtained using tree-level determinations of the CKM matrix and the recent lattice QCD results for the relevant hadronic matrix elements. Last but not least, we advocate kaon physics as a unique probe of very high energy scales and briefly discuss the current status of ${\epsilon }^{\prime }/\epsilon$ and $K\to \pi \nu \bar{\nu }$.

    hep-phPoS(2019)·6 citations
22. 22*

    Searching for a Sterile Neutrino in Tau Decays at B-factories

    C.O. Dib🇨🇱 · J.C. Helo🇨🇱 · M. Nayak🇺🇸 · N.A. Neill🇨🇱 · A. Soffer🇮🇱 · J. Zamora-Saa🇨🇱

    The phenomenon of neutrino flavor oscillations motivates searches for sterile neutrinos in a broad range of masses and mixing-parameter values. A sterile neutrino $N$ that mixes predominantly with the $\tau$ neutrino is particularly challenging experimentally. To address this challenge, we propose a new method to search for a ${\nu }_{\tau }$-mixing with $N$ lighter than the $\tau$ lepton. The method uses the large $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}$ samples collected at $B$-factory experiments to produce the $N$ in $\tau$-lepton decays. We exploit the long lifetime of a sterile neutrino in this mass range to suppress background and apply kinematic and vertexing constraints that enable measuring the sterile neutrino mass. Estimates for the sensitivities of the BaBar, Belle, and Belle~II experiments are calculated and presented.

    hep-phPRD(2020)·47 citations
23. 23*

    Vector gauge boson radiation from compact binary systems in a gauged $L_{\mu }-L_{\tau }$ scenario

    Tanmay Kumar Poddar🇮🇳 · Subhendra Mohanty🇮🇳 · Soumya Jana🇮🇳

    The orbital period of a compact binary system decays mainly due to quadrupole gravitational radiation, which agrees with the observation to within one percent. Other types of radiation such as ultralight scalar or pseudoscalar radiation, massive vector boson radiation also contribute to the decay of orbital period as long as the mass of the emitted particle is less than the orbital frequency of the compact binary system. We obtain an expression of the energy loss due to the radiation of massive vector field from the neutron star-neutron star and neutron star-white dwarf binaries. Due to large chemical potential of the degenerate electrons, neutron stars have large muon charge. We derive the energy loss due to $U(1{)}_{L_{\mu }-L_{\tau }}$ gauge boson radiation from the binaries. For the radiation of vector boson, the mass is restricted by $M_{Z^{\prime }}<\Omega \simeq 10^{-19}eV$ are the orbital frequencies of the compact star binaries. Using the formula of orbital period decay, we obtain constraints on the coupling constant of the gauge boson in the gauged $L_{\mu }-L_{\tau }$ theory for the four compact binary systems. For vector gauge boson muon coupling we find that for $M_{Z^{\prime }}<10^{-19}eV$, constraints on the coupling constant is $g<\mathcal{O}(10^{-20})$. We also obtain the exclusion plots of the massive vector proca field and the gauge field which can couple to muons.

    hep-phastro-ph.COgr-qcPRD(2019)·78 citations
24. 24*

    Structures of the Massive Vector Boson Propagators at Finite Temperature Illuminated by the Goldstone Equivalence Gauge

    Yi-Lei Tang🇰🇷

    Inspired by the Goldstone equivalence gauge, we study the thermal corrections to an originally massive vector boson by checking the poles and branch cuts. We find that part of the Goldstone boson is spewed out from the longitudinal polarization, becoming a branch cut which can be approximated by the "quasi-poles" in the thermal environment. In this case, physical Goldstone boson somehow partly recovers. We also show the Feynmann rules for the "external legs" of these vector boson as well as the recovered Goldstone boson, expecting to simplify the vector boson participated process calculations by adopting the similar "tree-level" logic as in the zero temperature situation. Gauge boson mixing case are also discussed. Similar results are shown in other gauges, especially in the $R_{\xi }$ gauge.

    hep-phJHEP(2020)·2 citations
25. 25*

    Probing the freeze-in mechanism in dark matter models with $U(1{)}^{\prime }$ gauge extensions

    Saniya Heeba🇩🇪 · Felix Kahlhoefer🇩🇪

    New gauge bosons at the MeV scale with tiny gauge couplings (so-called dark photons) can be responsible for the freeze-in production of dark matter and provide a clear target for present and future experiments. We study the effects of thermal mixing between dark photons and Standard Model gauge bosons and of the resulting plasmon decays on dark matter production before and after the electroweak phase transition. In the parameter regions preferred by the observed dark matter relic abundance, the dark photon is sufficiently long-lived to be probed with fixed-target experiments and light enough to induce direct detection signals. Indeed, current limits from XENON1T already constrain Dirac fermion dark matter in the GeV to TeV range produced via the freeze-in mechanism. We illustrate our findings for the case of a $U(1{)}_{B-L}$ gauge extension and discuss possible generalisations.

    hep-phastro-ph.COPRD(2020)·54 citations
26. 26*

    Displaced heavy neutrinos from $Z^{\prime }$ decays at the LHC

    Cheng-Wei Chiang🇹🇼 · Giovanna Cottin🇹🇼 · Arindam Das🇯🇵 · Sanjoy Mandal🇮🇳

    We study the LHC sensitivity to probe a long-lived heavy neutrino $N$ in the context of $Z^{\prime }$ models. We focus on displaced vertex signatures of $N$ when pair produced via a $Z^{\prime }$, decaying to leptons and jets inside the inner trackers of the LHC experiments. We explore the LHC reach with current long-lived particle search strategies for either one or two displaced vertices in association with hadronic tracks or jets. We focus on two well-motivated models, namely, the minimal $U(1{)}_{B-L}$ scenario and its $U(1{)}_X$ extension. We find that searches for at least one displaced vertex can cover a significant portion of the parameter space, with light-heavy neutrino mixings as low as $|V_{lN}{|}^2\approx 10^{-17}$, and $l=e,\mu$ accessible across GeV scale heavy neutrino masses.

    hep-phhep-exJHEP(2019)·81 citations
27. 27*

    Dark Matter and Naturalness

    Mark P. Hertzberg🇺🇸 · McCullen Sandora🇺🇸

    The Standard Model of particle physics is governed by Poincaré symmetry, while all other symmetries, exact or approximate, are essentially dictated by theoretical consistency with the particle spectrum. On the other hand, many models of dark matter exist that rely upon the addition of new added global symmetries in order to stabilize the dark matter particle and/or achieve the correct abundance. In this work we begin a systematic exploration into truly natural models of dark matter, organized by only relativity and quantum mechanics, without the appeal to any additional global symmetries, no fine-tuning, and no small parameters. We begin by reviewing how singlet dark sectors based on spin 0 or spin $\frac{1}{2}$ should readily decay, while pure strongly coupled spin 1 models have an overabundance problem. This inevitably leads us to construct chiral models with spin $\frac{1}{2}$ particles charged under confining spin 1 particles. This leads to stable dark matter candidates that are analogs of baryons, with a confinement scale that can be naturally $\mathcal{O}(100)$TeV. This leads to the right freeze-out abundance by annihilating into massless unconfined dark fermions. The minimal model involves a dark copy of $SU(3)\times SU(2)$ with 1 generation of chiral dark quarks and leptons. The presence of massless dark leptons can potentially give rise to a somewhat large value of $\Delta N_{\text{eff}}$ during BBN. In order to not upset BBN one may either appeal to a large number of heavy degrees of freedom beyond the Standard Model, or to assume the dark sector has a lower reheat temperature than the visible sector, which is also natural in this framework. This reasoning provides a robust set of dark matter models that are entirely natural. Some are concrete realizations of the nightmare scenario in which dark matter may be very difficult to detect, which may impact future search techniques.

    hep-phastro-ph.COastro-ph.HEhep-thJHEP(2019)·15 citations
28. 28*

    Dark Neutrino interactions phase out the Hubble tension

    Subhajit Ghosh🇮🇳 · Rishi Khatri🇮🇳 · Tuhin S. Roy🇮🇳

    New interactions of neutrinos can stop them from free streaming even after the weak interaction freeze-out. This results in a phase shift in the cosmic microwave background (CMB) acoustic peaks which can alleviate the Hubble tension. In addition, the perturbations in neutrinos do not decay away on horizon entry and contribute to metric perturbation enhancing the matter power spectrum. We demonstrate that this acoustic phase shift can be achieved using new interactions of standard left-handed neutrinos with dark matter without changing the number of effective relativistic degrees of freedom. Using Planck CMB and the WiggleZ galaxy survey $(k\le 0.12h{\mathrm{Mpc}}^{-1})$ data, we demonstrate that in this model the Hubble tension reduces to approximately $2.1\sigma$. Our model predicts potentially observable modifications of the CMB B-modes and the matter power spectrum that can be observed in future data sets.

    hep-phastro-ph.COPRD(2020)·82 citations
29. 29*

    Consistency of the Standard Model Effective Field Theory

    Grant N. Remmen🇺🇸 · Nicholas L. Rodd🇺🇸

    We derive bounds on couplings in the standard model effective field theory (SMEFT) as a consequence of causality and the analytic structure of scattering amplitudes. In the SMEFT, there are 64 independent operators at mass dimension eight that are quartic in bosons (either Higgs or gauge fields) and that contain four derivatives and/or field strengths, including both CP-conserving and CP-violating operators. Using analytic dispersion relation arguments for two-to-two bosonic scattering amplitudes, we derive 27 independent bounds on the sign or magnitude of the couplings. We show that these bounds also follow as a consequence of causality of signal propagation in nonvacuum SM backgrounds. These bounds come in two qualitative forms: i) positivity of (various linear combinations of) couplings of CP-even operators and ii) upper bounds on the magnitude of CP-odd operators in terms of (products of) CP-even couplings. We exhibit various classes of example completions, which all satisfy our EFT bounds. These bounds have consequences for current and future particle physics experiments, as part of the observable parameter space is inconsistent with causality and analyticity. To demonstrate the impact of our bounds, we consider applications both to SMEFT constraints derived at colliders and to limits on the neutron electric dipole moment, highlighting the connection between such searches suggested by infrared consistency.

    hep-phhep-thJHEP(2019)·172 citations
30. 30*

    Composite Higgs models

    Juan Pablo Hoyos Daza🇧🇷

    One of the solutions to the hierarchy problem of the Standard Model is the composite Higgs scenario, where the Higgs emerges as a composite pseudo-Nambu-Goldstone boson. In this work we present and study the basic characteristics of the composite Higgs scenario, based on the $SO(5)/SO(4)$ and $SO(6)/SO(5)$ cosets. We construct their effective Lagrangians through the Callan-Coleman-Wess-Zumino construction. The first coset does not differ much from the Standard Model and the second contains a singlet scalar in addition to the Higgs doublet. In these models we study the gauge sector, the fermion sector and we estimate the composite Higgs potential.

    hep-ph2 citations
31. 31*

    NuSTAR Tests of Sterile-Neutrino Dark Matter: New Galactic Bulge Observations and Combined Impact

    Brandon M. Roach🇺🇸 · Kenny C. Y. Ng🇮🇱 · Kerstin Perez🇺🇸 · John F. Beacom🇺🇸 · Shunsaku Horiuchi🇺🇸 · Roman Krivonos🇷🇺 · Daniel R. Wik🇺🇸

    We analyze two dedicated NuSTAR observations with exposure $\sim 190$ ks located $\sim 10^{\circ }$ from the Galactic plane, one above and the other below, to search for x-ray lines from the radiative decay of sterile-neutrino dark matter. These fields were chosen to minimize astrophysical x-ray backgrounds while remaining near the densest region of the dark matter halo. We find no evidence of anomalous x-ray lines in the energy range 5--20 keV, corresponding to sterile neutrino masses 10--40 keV. Interpreted in the context of sterile neutrinos produced via neutrino mixing, these observations provide the leading constraints in the mass range 10--12 keV, improving upon previous constraints in this range by a factor $\sim 2$. We also compare our results to Monte Carlo simulations, showing that the fluctuations in our derived limit are not dominated by systematic effects. An updated model of the instrumental background, which is currently under development, will improve NuSTAR's sensitivity to anomalous x-ray lines, particularly for energies 3--5 keV.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2020)·121 citations
32. 32*

    Chiral perturbation theory vs. Linear Sigma Model in a chiral imbalance medium

    A. A. Andrianov🇷🇺 · V. A. Andrianov🇷🇺 · D. Espriu🇪🇸

    We compare Chiral Perturbation Theory (ChPT) and the Linear Sigma Model (LSM) as realizations of low energy QCD for light mesons in a chirally imbalanced medium. The relations between the low-energy constants of the Chiral Lagrangian and the corresponding constants of the Linear Sigma Model are established as well as the expressions for the decay constant of the $\pi$-meson in the medium and the mass of the $a_0$. In the large $N_c$ count taken from QCD the correspondence of ChPT and LSM is remarkably good and give a solid ground for search of chiral imbalance manifestation in pion physics. A possible experimental detection of chiral imbalance tracks (and therefore a phase with Local Parity Breaking) in the charged pion decays inside the fireball is outlined.

    ↳ hep-thhep-phParticles(2020)·23 citations
33. 33*

    Thermal Components in Gamma-ray Bursts. II. Constraining the Hybrid Jet Model

    Liang Li🇮🇹

    In explaining the physical origin of the jet composition of gamma-ray bursts (GRBs), a more general picture, i.e. the hybrid jet model (which introduced another magnetization parameter ${\sigma }_0$ on the basis of the traditional fireball model), has been well studied in Gao \& Zhang. However, it still has not yet been applied to a large GRB sample. Here, we first employ the "top-down" approach of Gao \& Zhang to diagnose the photosphere properties at the central engine to see how the hybrid model can account for the observed data as well, through applying a {\it Fermi} GRB sample (eight bursts) with the detected photosphere component, as presented in Li (our Paper I). We infer all physical parameters of a hybrid problem with three typical values of the radius of the jet base ($r_0$ = 10${}^7$, 10${}^8$, and 10${}^9$ cm). We find that the dimensionless entropy for all the bursts shows $\eta \gg$ 1 while the derived (1+${\sigma }_0$) for five bursts (GRB 081224, GRB 110721A, GRB 090719, GRB 100707, and GRB 100724) is larger than unity, indicating that in addition to a hot fireball component, another cold Poynting-flux component may also play an important role. Our analysis also shows that in a few time bins for all $r_0$ in GRB 081224 and GRB 110721A, the magnetization parameter at $\sim$ 10${}^{15}$cm (1+${\sigma }_{r15}$) is greater than unity, which implies that internal-collision-induced magnetic reconnection and turbulence may be the mechanism to power the nonthermal emission, rather than internal shocks. We conclude that the majority of bursts (probably all) can be well explained by the hybrid jet problem.

    ↳ astro-ph.HEhep-phApJ(2020)·33 citations
34. 34*

    Covariant Spectator Theory of $np$ scattering: Deuteron form factors

    Franz Gross🇺🇸

    The deuteron form factors are calculated using two model wave functions obtained from the 2007 CST high precision fits to $np$ scattering data. Included in the calculation are a new class of isoscalar $np$ interaction currents which are automatically generated by the nuclear force model used in these fits. If the nuclear model WJC2 is used, a precision fit (${\chi }^2$/datum $\eqsim 1$) to the Sick Global Analysis (GA) of all $ed$ elastic scattering data can be obtained by adjusting the unknown off-shell nucleon form factors $F_3(Q^2)$ (discussed before) and $F_4(Q^2)$ (introduced in this paper), and predicting the high $Q^2$ behavior of the neutron charge form factor $G_{En}(Q^2)$ well beyond the region where it has been measured directly. Relativistic corrections, isoscalar interaction currents, and off-shell effects are defined, discussed, and their size displayed. A rationale for extending $ed$ elastic scattering measurements to higher $Q^2$ is presented.

    ↳ nucl-thhep-exhep-phPRC(2020)·9 citations
35. 35*

    Ultralight dark photon as a model for early universe dark matter

    V.V. Flambaum🇦🇺 · I.B. Samsonov🇦🇺

    Dark photon is a massive vector field which interacts only with the physical photon through the kinetic mixing. This coupling is assumed to be weak so that the dark photon becomes almost unobservable in processes with elementary particles, but can serve as a dark matter particle. We argue that in very early Universe ($z>3000$) this vector field may have the equation of state of radiation ($w=1/3$) but later behaves as cold dark matter ($w=0$). This may slightly change the expansion rate of the Universe at early time and reduce the value of the sound horizon of baryon acoustic oscillations (standard ruler). As a result, in this model the value of the Hubble constant appears to be larger than that in the standard $\Lambda$CDM model. In particular, it is sufficient to have the dark photon mass of order $m\sim 10^{-27}-10^{-25}$ eV to fit the value of the Hubble constant to $H_0=73$ km$\cdot$s${}^{-1}$Mpc${}^{-1}$ thus resolving the Hubble tension.

    ↳ astro-ph.COhep-phPRD(2019)·18 citations
36. 36*

    Meson Screening Masses in (2+1)-Flavor QCD

    Alexei Bazavov🇺🇸 · Simon Dentinger🇩🇪 · Heng-Tong Ding🇨🇳 · Prasad Hegde🇮🇳 · Olaf Kaczmarek🇩🇪 · Frithjof Karsch🇩🇪 · Edwin Laermann🇩🇪 · Anirban Lahiri🇩🇪 · Swagato Mukherjee🇺🇸 · Hiroshi Ohno🇯🇵 · Peter Petreczky🇺🇸 · Rishabh Thakkar🇮🇳 and 4 other authors

    We present lattice QCD results for mesonic screening masses in the temperature range 140 MeV $\lesssim T\lesssim$ 2500 MeV. Our calculations were carried out using (2+1)-flavors of the Highly Improved Staggered Quark (HISQ) action, with a physical value for the strange quark mass and two values of the light quark mass corresponding to pion masses of 160 MeV and 140 MeV. Continuum-extrapolated results were obtained using calculations with a variety of lattice spacings corresponding to temporal lattice extents $N_{\tau }=6-16$. We discuss the implications of these results for the effective restoration of various symmetries in the high temperature phase of QCD, as well as the approach toward the perturbative limit.

    ↳ hep-lathep-phnucl-thPRD(2019)·149 citations
37. 37*

    Salecker-Wigner-Karolyhazy Gedankenexperiment in light of the self-gravity

    Michael Maziashvili🇬🇪

    In Gedankenexperiment mentioned in the title, the imprecision in space-time measurement is related to the spreading of clock's wave-function with the passage of time required for the measurement. Special relativity puts a bound on the measurement time, it cannot be reduced arbitrarily as the signal used for the measurement cannot propagate with speed greater than that of light. In view of this reasoning, one is led to conclude that the clock should be heavy enough to slow down its wave-function from spreading with time. However, the general relativity puts an upper bound on clock's mass, since its size must remain greater then the Schwarzschild radius associated to it. This way one reaches a limit in length measurement. However, as is discussed below, an additional insight into the question comes by taking into account self-gravitational effects. As a result, the uncertainty in length measurement is reduced to the Planck length.

    ↳ gr-qchep-phhep-thGen.Rel.Grav.(2020)·0 citations
38. 38*

    Supersymmetry and the collider Dark Matter picture

    Jeanette Miriam Lorenz🇩🇪

    One of the key questions in particle physics and astrophysics is the nature of dark matter, which existence has been confirmed in many astrophysical and cosmological observations. Besides direct and indirect detection experiments, collider searches for dark matter offer the unique possibility to not only detect dark matter particles but in case of discovery to also study their properties by making statements about the potential underlying theory. The search program for dark matter at the ATLAS and CMS experiments at the Large Hadron Collider is comprehensive, and includes both supersymmetric dark matter candidates and other alternatives. This review presents the latest status in these searches, with special focus on supersymmetric dark matter particles.

    ↳ hep-exhep-phMod.Phys.Lett.A(2019)·6 citations
39. 39*

    Quadratic, Higgs and hilltop potentials in the Palatini gravity

    Nilay Bostan🇺🇸

    In this work, we study inflation with the non-minimally coupled quadratic, Standard Model (SM) Higgs and hilltop potentials through $\xi {\varphi }^{2}R$ term in the Palatini gravity. We first analyze observational parameters of Palatini quadratic potential as functions of $\xi$ for high-$N$ scenario and low-$N$ scenario. In addition to this, taking into account inflaton $\varphi$ has a non-zero vacuum expectation value $v$ afterwards inflation, we display observational parameters of well-known symmetry-breaking potentials type of Higgs potential and its generalizations which are hilltop potentials in the Palatini formalism for high-$N$ scenario and low-$N$ scenario. We calculate inflationary parameters of Palatini Higgs potential as functions of $v$ for different $\xi$ values where inflaton values both $\varphi >v$ and $\varphi <v$ during inflation as well as we show that observational parameters of Palatini Higgs potential in the induced gravity limit for high-$N$ scenario. On the other hand, we illustrate different from the Higgs potential the effect of $\xi$ on hilltop potentials which can agree with the observations for inflaton value solely $\varphi <v$ and $\xi$, $v\ll 1$ for both two scenarios, which we mentioned above. For each considered potentials, we also display $n_s-r$ values fit the current data given by the Keck Array/BICEP2 and Planck collaborations.

    ↳ astro-ph.COhep-phCommun.Theor.Phys.(2020)·36 citations
40. 40*

    Statistical sensitivity estimates for oscillating electric dipole moment measurements in storage rings

    Jörg Pretz🇩🇪 · Seung Pyo Chang🇰🇷 · Volker Hejny🇩🇪 · Swathi Karanth🇵🇱 · Seongtae Park🇰🇷 · Yannis Semertzidis🇰🇷 · Ed Stephenson🇺🇸 · Hans Ströher🇩🇪

    In this paper analytical expressions are derived to describe the spin motion of a particle in magnetic and electric fields in the presence of an axion field causing an oscillating electric dipole moment (EDM). These equations are used to estimate statistical sensitivities for axion searches at storage rings. The estimates obtained from the analytic expressions are compared to numerical estimates from simulations in S.P. Chang et al (Phys.Rev. D99 (2019) no.8, 083002). A good agreement is found.

    ↳ hep-exhep-phEPJC(2020)·24 citations
41. 41*

    Effective energy density of relic gravitons

    Massimo Giovannini🇨🇭

    The energy density, the pressure and the anisotropic stress of the relic gravitons do not have a unique gauge-invariant and frame-invariant expression since the equivalence principle ultimately forbids the localization of the energy-momentum of the gravitational field. All the strategies proposed so far suggest compatible descriptions inside the effective horizon but they lead to sharply different answers when the wavelengths of the gravitons exceed the Hubble radius by remaining shorter than the typical extension of causally connected patches. We present a coherent discussion of the energy-momentum pseudo-tensors of the relic gravitons in the different kinematical regimes with the aim of scrutinizing the mutual consistency of the competing suggestions. The various proposals are systematically compared by deducing and analyzing the explicit form of the observables in realistic physical situations. General lessons are drawn on the most plausible parametrization of the energy-momentum pseudo-tensor of the relic gravitons.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2019)·28 citations
42. 42*

    Real scalar field kink(-antikink)s and their perturbation spectra in a closed universe

    Betti Hartmann (IFSC/USP, Brazil & UPV/EHU Bilbao, Spain)🇧🇷 · Gabriel Luchini (UFES Vitória, Brazil)🇧🇷 · Clisthenis P. Constantinidis (UFES Vitória, Brazil)🇧🇷 · Carlos F.S. Pereira (UFES Vitória, Brazil)🇧🇷

    In this paper we demonstrate that solitons of a simple real scalar field model that are {\it static and linearly stable} do exist when considered in a (3+1)-dimensional, spatially compact space-time background, the static Einstein universe, which is a good approximation to the observed universe for sufficiently small time intervals. We study the properties of these solutions for a ${\Phi }^4$-potential and demonstrate that next to the fundamental solutions, excited configurations exist. We also investigate general perturbations about the solitons, determine their eigenfrequency spectra and compare them with those of the perturbations about the vacua of the model. We find that the degeneracy with respect to the multipoles of the perturbation, which is present for the vacua, does no longer exist in the presence of the soliton. Moreover, specific perturbations correspond to zero modes of the system. Our results have applications in condensed matter physics as well as computations of quantum effects (e.g. the Casimir energy) in spatially compact space-times in the presence of soliton-like objects.

    ↳ hep-thgr-qchep-phPRD(2020)·7 citations
43. 43*

    Neutron Star Matter as a Relativistic Fermi Liquid

    Bengt Friman🇩🇪 · Wolfram Weise🇩🇪

    The equation of state (EoS) of neutron star matter, constrained by the existence of two-solar-mass stars and gravitational wave signals from neutron star mergers, is analysed using the Landau theory of relativistic Fermi liquids. While the phase diagram of dense and cold QCD matter is still open for scenarios ranging from hadronic to quark matter in the center of neutron stars, a Fermi-liquid treatment is motivated by a microscopic approach starting from a chiral nucleon-meson field theory combined with nonperturbative functional renormalization group methods. In this scheme effects of multipionic fluctuations and repulsive nuclear many-body correlations suggest that the transition to chiral symmetry restoration is shifted to densities above those typically encountered in the neutron star core. Under such conditions a Fermi-liquid description in terms of nucleon quasiparticles appears to be justified. The leading Landau parameters are derived and discussed. Our results are contrasted with a well-known Fermi liquid, namely liquid ${}^3$He.

    ↳ nucl-thastro-ph.HEhep-phPRC(2020)·34 citations
44. 44*

    Thermodynamics of hot strong-interaction matter from ultrarelativistic nuclear collisions

    Fernando G. Gardim🇧🇷 · Giuliano Giacalone🇫🇷 · Matthew Luzum🇧🇷 · Jean-Yves Ollitrault🇫🇷

    Collisions between heavy atomic nuclei at ultra-relativistic energies are carried out at particle colliders to produce the quark-gluon plasma, a state of matter where quarks and gluons are not confined into hadrons, and colour degrees of freedom are liberated. This state is thought to be produced as a transient phenomenon before it fragments into thousands of particles that reach the particle detectors. Despite two decades of investigations, one of the big open questions is to obtain an experimental determination of the temperature reached in a heavy-ion collision, and a simultaneous determination of another thermodynamic quantity, such as the entropy density, that would give access to the number of degrees of freedom. Here we obtain the first such determination, utilizing state-of-the-art hydrodynamic simulations. We define an effective temperature, averaged over the space-time evolution of the medium. Then, using experimental data, we determine this temperature, the corresponding entropy density and speed of sound in the matter created in lead-lead collisions at the Large Hadron Collider. Our results agree with first-principles calculations from lattice quantum chromodynamics and confirm that a deconfined phase of matter is indeed produced.

    ↳ nucl-thhep-phnucl-exNat.Phys.(2020)·138 citations
45. 45*

    Coherent elastic neutrino-nucleus scattering on 40Ar from first principles

    C. G. Payne🇩🇪 · S. Bacca🇩🇪 · G. Hagen🇺🇸 · W. Jiang🇺🇸 · T. Papenbrock🇺🇸

    Coherent elastic neutrino scattering on the 40Ar nucleus is computed with coupled-cluster theory based on nuclear Hamiltonians inspired by effective field theories of quantum chromodynamics. Our approach is validated by calculating the charge form factor and comparing it to data from electron scattering. We make predictions for the weak form factor, the neutron radius, and the neutron skin, and estimate systematic uncertainties. The neutron-skin thickness of 40Ar40 is consistent with results from density functional theory. Precision measurements from coherent elastic neutrino-nucleus scattering could potentially be used to extract these observables and help to constrain nuclear models.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2019)·76 citations
46. 46*

    Lower bound on the primordial black hole merger rate

    Ville Vaskonen🇬🇧 · Hardi Veermäe🇪🇪

    We derive a lower bound on the merger rate of primordial black hole (PBH) binaries by estimating the maximal fraction of binaries that were perturbed between formation in the early Universe and merger, and computing a conservative merger rate of perturbed binaries. This implies robust constraints on the PBH abundance in the range $1-100M_{\odot }$. We further show that LIGO/Virgo design sensitivity has the potential to reach the PBH mass range of $10^{-2}-10^3{M}_{\odot }$. The constraint from the merger rate of perturbed binaries is stronger if PBHs are initially spatially clustered.

    ↳ astro-ph.COastro-ph.HEhep-phPRD(2020)·235 citations
47. 47*

    Parton Distribution Functions from Ioffe time pseudo-distributions

    Bálint Joó🇺🇸 · Joseph Karpie🇺🇸 · Kostas Orginos🇺🇸 · Anatoly Radyushkin🇺🇸 · David Richards🇺🇸 · Savvas Zafeiropoulos🇫🇷

    In this paper, we present a detailed study of the unpolarized nucleon parton distribution function (PDF) employing the approach of parton pseudo-distribution functions. We perform a systematic analysis using three lattice ensembles at two volumes, with lattice spacings $a=$ 0.127 fm and $a=$ 0.094 fm, for a pion mass of roughly 400 MeV. With two lattice spacings and two volumes, both continuum limit and infinite volume extrapolation systematic errors of the PDF are estimated. In addition to the $x$ dependence of the PDF, we compute their first two moments and compare them with the pertinent phenomenological determinations.

    ↳ hep-lathep-phJHEP(2019)·115 citations
48. 48*

    A Sterile Neutrino Search at compact materials irradiation facility

    Liangwen Chen🇨🇳 · Han-Jie Cai🇨🇳 · Emilio Ciuffoli🇨🇳 · Jarah Evslin🇨🇳 · Fen Fu🇨🇳 · Sheng Zhang🇨🇳 · Xurong Chen🇨🇳 · Lei Yang🇨🇳 · Wenlong Zhan🇨🇳

    The compact material irradiation facility (CMIF) is a current project in China that will provide a compact deuteron-beryllium neutron source. The target of this facility will be an intense and compact Isotope Decay-At-Rest (IsoDAR) neutrino source. In this paper, we propose to test the sterile neutrino hypothesis using CMIF as the neutrino source. At CMIF platform, the electron antineutrino production rate can be up to $2.0\times 10^{19}$ per day. When paired with an 80 t liquid scintillator detector to study short baseline electron antineutrino disappearance, the inverse beta decay (IBD) event rate is large enough to investigate the parameter ranges of interest for neutrino anomalies. Our sensitivity analysis shows that a short baseline experiment at this platform will provide a very competitive sterile neutrino search, especially in the high-$\Delta m^2$ region ($\Delta m^2>10{\text{eV}}^2$).

    ↳ physics.ins-dethep-exhep-phEPJC(2020)·0 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.