Wed·Apr 17, 2019Wednesday·April 17, 2019

1. 01*

   Physics with Beam Tau-Neutrino Appearance at DUNE

   André de Gouvêa🇺🇸 · Kevin J. Kelly🇺🇸 · G. V. Stenico🇧🇷 · Pedro Pasquini🇧🇷

   We explore the capabilities of the upcoming Deep Underground Neutrino Experiment (DUNE) to measure ${\nu }_{\tau }$ charged-current interactions and the associated oscillation probability $P({\nu }_{\mu }\to {\nu }_{\tau })$ at its far detector, concentrating on how such results can be used to probe neutrino properties and interactions. DUNE has the potential to identify significantly more ${\nu }_{\tau }$ events than all existing experiments and can use this data sample to nontrivially test the three-massive-neutrinos paradigm by providing complementary measurements to those from the ${\nu }_e$ appearance and ${\nu }_{\mu }$ disappearance channels. We further discuss the sensitivity of the ${\nu }_{\tau }$ appearance channel to several hypotheses for the physics that may lurk beyond the three-massive-neutrinos paradigm: a non-unitary lepton mixing matrix, the $3+1$ light neutrinos hypothesis, and the existence of non-standard neutral-current neutrino interactions. Throughout, we also consider the relative benefits of the proposed high-energy tune of the Long-Baseline Neutrino Facility (LBNF) beam-line.

   hep-phhep-exPRD(2019)·88 citations
2. 02*

   Minimal Dirac Neutrino Mass Models from $U(1{)}_R$ Gauge Symmetry and Left-Right Asymmetry at Colliders

   Sudip Jana🇺🇸 · Vishnu P.K.🇺🇸 · Shaikh Saad🇺🇸

   In this work, we propose minimal realizations for generating Dirac neutrino masses in the context of a right-handed abelian gauge extension of the Standard Model. Utilizing only $U(1{)}_R$ symmetry, we address and analyze the possibilities of Dirac neutrino mass generation via (a) \textit{tree-level seesaw} and (b) \textit{radiative correction at the one-loop level}. One of the presented radiative models implements the attractive \textit{scotogenic} model that links neutrino mass with Dark Matter (DM), where the stability of the DM is guaranteed from a residual discrete symmetry emerging from $U(1{)}_R$. Since only the right-handed fermions carry non-zero charges under the $U(1{)}_R$, this framework leads to sizable and distinctive Left-Right asymmetry as well as Forward-Backward asymmetry discriminating from $U(1{)}_{B-L}$ models and can be tested at the colliders. We analyze the current experimental bounds and present the discovery reach limits for the new heavy gauge boson $Z^{\prime }$ at the LHC and ILC. Furthermore, we also study the associated charged lepton flavor violating processes, dark matter phenomenology and cosmological constraints of these models.

   hep-phhep-exEPJC(2019)·74 citations
3. 03*

   One-loop three-point Feynman integrals with Appell $F_1$ hypergeometric functions

   Khiem Hong Phan🇻🇳 · Dzung Tri Tran🇻🇳

   New analytic formulas for one-loop three-point Feynman integrals in general space-time dimension ($d$) are presented in this paper. The calculations are performed at general configurations for internal masses and external momenta. The analytic results are expressed in terms of hypergeometric series ${}_2{F}_1$, ${}_3{F}_2$ for special cases and Appell $F_1$ for general cases. Furthermore, we cross-check our analytic results with other references which have carried out the integrals in several special cases.

   hep-phPTEP(2019)·11 citations
4. 04*

   Single production of vector-like top partner decaying to $Wb$ in the leptonic channel at $ep$ colliders in the LHT model

   Bingfang Yang🇨🇳 · Biaofeng Hou🇨🇳 · Huaying Zhang🇨🇳 · Ning Liu🇨🇳

   In the littlest Higgs model with T-parity(LHT), we study the single production of vector-like top partner with the subsequent decay $T_{+}\to Wb$ in the leptonic channel at the $ep$ colliders. Focus on the LHeC ($\sqrt{s}$ = 1.98 TeV) and FCC-eh ($\sqrt{s}$ = 5.29 TeV), we investigate the observability of the single top partner production with the unpolarized and polarized electron beams, respectively. As a result, the statistical significance can be enhanced by the polarized electron beams. Under the current constraints, the search for $T_{+}$ in the $Wb$ channel at the LHeC cannot provide a stronger limit on the top partner mass. By contrast, the search for the $T_{+}$ in this channel at the FCC-eh with polarized $e^{-}$ beams can exclude the top partner mass up to 1350 GeV, 1500 GeV and 1565 GeV with integrated luminosities of 100 fb${}^{-1}$, 1000 fb${}^{-1}$ and 3000 fb${}^{-1}$ at the 2$\sigma$ level, which is an improvement with respect to the current indirect searches and the LHC direct searches. Furthermore, we also give an extrapolation to the high-luminosity LHC with $\sqrt{s}=14$ TeV and $L=3000{\mathrm{fb}}^{-1}$. Our results show that the LHT model is still a natural solution to the shortcomings of the electroweak and scalar sector although it has been constrained severely.

   hep-phPRD(2019)·14 citations
5. 05*

   Decays of $X(3872)$ to ${\chi }_{cJ}{\pi }^0$ and $J/\psi {\pi }^{+}{\pi }^{-}$

   Zhi-Yong Zhou🇨🇳 · Meng-Ting Yu🇨🇳 · Zhiguang Xiao🇨🇳

   By describing the $X(3872)$ using the extended Friedrichs scheme, in which $D{\bar{D}}^{\ast }$ is the dominant component, we calculate the decay rates of the $X(3872)$ to ${\pi }^0$ and a $P$-wave charmonium ${\chi }_{cJ}$ state with $J=0,1$, or $2$, and its decays to $J/\psi {\pi }^{+}{\pi }^{-}$ where ${\pi }^{+}{\pi }^{-}$ are assumed to be produced via an intermediate $\rho$ state. The decay widths of $X(3872)\to {\chi }_{cJ}{\pi }^0$ for $J=0,1,2$ are of the same order. However, this model calculation exhibits that the decay rate of $X(3872)$ to ${\chi }_{c1}{\pi }^0$ is one order of magnitude smaller than its decay rate to $J/\psi {\pi }^{+}{\pi }^{-}$.

   hep-phhep-exPRD(2019)·20 citations
6. 06*

   A feeble window on leptophilic dark matter

   Sam Junius🇧🇪 · Laura Lopez-Honorez🇧🇪 · Alberto Mariotti🇧🇪

   In this paper we study a leptophilic dark matter scenario involving feeble dark matter coupling to the Standard Model (SM) and compressed dark matter-mediator mass spectrum. We consider a simplified model where the SM is extended with one Majorana fermion, the dark matter, and one charged scalar, the mediator, coupling to the SM leptons through a Yukawa interaction. We first discuss the dependence of the dark matter relic abundance on the Yukawa coupling going continuously from freeze-in to freeze-out with an intermediate stage of conversion driven freeze-out. Focusing on the latter, we then exploit the macroscopic decay length of the charged scalar to study the resulting long-lived-particle signatures at collider and to explore the experimental reach on the viable portion of the parameter space.

   hep-phJHEP(2019)·47 citations
7. 07*

   Semileptonic decays $B_c\to ({\eta }_c,J/\psi )l{\bar{\nu }}_l$ in the "PQCD + Lattice" approach

   Xue-Qing Hu🇨🇳 · Su-Ping Jin🇨🇳 · Zhen-Jun Xiao🇨🇳

   In this paper, we studied the semileptonic decays $B_c^{-}\to ({\eta }_c,J/\psi )l^{-}{\bar{\nu }}_l$ by employing the PQCD factorization approach, using the newly defined distribution amplitudes of the $B_c$ meson and the new kind of parametrization for extrapolation of the form factors , and also taking into account the lattice QCD results about the relevant form factors at several points. We found the following main results: (a) the PQCD predictions for the branching ratios of $B_c\to ({\eta }_c,J/\psi )l\bar{\nu }$ decays will become a little smaller by about $(5-16)\%$ when the lattice input are taken into account in the extrapolation of the relevant form factors; (b) the PQCD predictions for the ratio $R_{{\eta }_c,J/\psi }$ and the longitudinal polarization $P_{\tau }$ are $R_{{\eta }_c}=0.34\pm 0.01,R_{J/\psi }=0.28\pm 0.01$, $P_{\tau }({\eta }_c)=0.37\pm 0.01$ and $P_{\tau }(J/\psi )=-0.55\pm 0.01$ ; and (c) after the inclusion of the lattice input the theoretical predictions changed slightly: $R_{{\eta }_c}=0.31\pm 0.01$, $R_{J/\psi }=0.27\pm 0.01$, $P_{\tau }({\eta }_c)=0.36\pm 0.01$ and $P_{\tau }(J/\psi )=-0.53\pm 0.01$. The theoretical predictions for $R_{J/\psi }$ agree with the measured one within errors, and other predictions could be tested in the near future LHCb experiments.

   hep-phhep-exCPC(2020)·43 citations
8. 08*

   Scotogenic S3 symmetric generation of realistic neutrino mixing

   Soumita Pramanick (Harish-Chandra Research Institute, India)🇮🇳

   Realistic neutrino mixing is achieved at one-loop level radiatively using $S3\times Z_2$ symmetry. The model comprises of two right-handed neutrinos, maximally mixed to produce the structure of the left-handed Majorana neutrino mass matrix characterized by ${\theta }_{13}=0$, ${\theta }_{23}=\pi /4$ and any value of ${\theta }_{12}^0$ particular to the Tribimaximal (TBM), Bimaximal (BM) and Golden Ratio (GR) or other mixings. A small deviation from this maximal mixing between the two right-handed neutrinos could generate non-zero ${\theta }_{13}$, shifts of the atmospheric mixing angle ${\theta }_{23}$ from $\pi /4$ and also could correct the solar mixing angle ${\theta }_{12}$ by a small amount altogether in a single step. In this scotogenic mechanism of generating non-zero ${\theta }_{13}$ by shifting from maximal mixing in the right-handed neutrino sector, two $Z_2$ odd inert scalar $SU(2{)}_L$ doublets were used, the lightest of which can serve as a dark matter candidate.

   hep-phPRD(2019)·23 citations
9. 09*

   SIMPler realisation of Scalar Dark Matter

   Subhaditya Bhattacharya🇮🇳 · Purusottam Ghosh🇮🇳 · Shivam Verma (IIT Guwahati)🇮🇳

   With growing agony of not finding a dark matter (DM) particle in direct search experiments so far (for example in XENON1T), frameworks where the freeze-out of DM is driven by number changing processes within the dark sector itself and do not contribute to direct search, like Strongly Interacting Massive Particle (SIMP) are gaining more attention. In this analysis, we ideate a simple scalar DM framework stabilised by $Z_3$ symmetry to serve with a SIMP-like DM ($\chi$) with additional light scalar mediation ($\varphi$) to enhance DM self interaction. We identify that a large parameter space for such DM is available from correct relic density and self interaction constraints coming from Bullet or Abell cluster data. We derive an approximate analytic solution for freeze-out of the SIMP like DM in Boltzmann Equation describing $3\to 2$ number changing process within the dark sector. We also provide a comparative analysis of the SIMP like solution with the Weakly Interacting Massive Particle (WIMP) realisation of the same model framework here.

   hep-phJCAP(2020)·21 citations
10. 10*

    Spontaneous generation of spin current from the vacuum by strong electric fields

    Xu-Guang Huang🇨🇳 · Mamoru Matsuo🇨🇳 · Hidetoshi Taya🇨🇳

    We discuss spontaneous spin current generation from the vacuum by strong electric fields as a result of interplay between the Schwinger mechanism and a spin-orbit coupling. By considering a homogeneous slow strong electric field superimposed by a fast weak transverse electric field, we explicitly evaluate the vacuum expectation value of a spin current (the Bargmann-Wigner spin current) by numerically solving the Dirac equation. We show that a non-vanishing spin current polarized in the direction perpendicular to the electric fields flows mostly in the longitudinal direction. We also find that a relativistic effect due to the helicity conservation affects direction/polarization of spin current.

    hep-phcond-mat.mes-hallcond-mat.mtrl-scihep-th+1PTEP(2019)·12 citations
11. 11*

    Unified description of LHC data on elastic $pp$ scattering

    Yu.M. Shabelski🇷🇺 · A.G. Shuvaev🇷🇺

    We present the unified description of the existing data on elastic small angle $pp$ and $p\bar{p}$ scattering at the energies 1.8, 1.96, 2.76, 7, 8 and 13~TeV in the framework of Additive Quark Model. The agreement with the data is quite reasonable.

    hep-phMod.Phys.Lett.A(2019)·1 citation
12. 12*

    Oscillating nuclear electric dipole moment induced by axion dark matter produces atomic and molecular EDM

    V. V. Flambaum🇦🇺 · H. B. Tran Tan🇦🇺

    According to the Schiff theorem nuclear electric dipole moment (EDM) is completely shielded in a neutral atom by electrons. This makes a static nuclear electric dipole moment (EDM) unobservable. Interaction with the axion dark matter field generates nuclear EDM $d=d_0\cos (\omega t)$ oscillating with the frequency $\omega =m_a{c}^2/\hslash$ . This EDM generates atomic EDM proportional to ${\omega }^2$. This effect is strongly enhanced in molecules since nuclei move slowly and do not produce as efficient screening of oscillating nuclear EDM as electrons do. An additional strong enhancement comes due to a small energy interval between rotational molecular levels. Finally, if the nuclear EDM oscillation frequency is in resonance with a molecular transition, there may be a significant resonance enhancement.

    hep-phquant-phPRD(2019)·24 citations
13. 13*

    Symmetry and geometry in generalized Higgs effective field theory -- Finiteness of oblique corrections v.s. perturbative unitarity

    Ryo Nagai🇯🇵 · Masaharu Tanabashi🇯🇵 · Koji Tsumura🇯🇵 · Yoshiki Uchida🇯🇵

    We formulate a generalization of Higgs effective field theory (HEFT) including arbitrary number of extra neutral and charged Higgs bosons (generalized HEFT, GHEFT) to describe non-minimal electroweak symmetry breaking models. Using the geometrical form of the GHEFT Lagrangian, which can be regarded as a nonlinear sigma model on a scalar manifold, it is shown that the scalar boson scattering amplitudes are described in terms of the Riemann curvature tensor (geometry) of the scalar manifold and the covariant derivatives of the potential. The coefficients of the one-loop divergent terms in the oblique correction parameters S and U can also be written in terms of the Killing vectors (symmetry) and the Riemann curvature tensor (geometry). It is found that perturbative unitarity of the scattering amplitudes involving the Higgs bosons and the longitudinal gauge bosons demands the flatness of the scalar manifold. The relationship between the finiteness of the electroweak oblique corrections and perturbative unitarity of the scattering amplitudes is also clarified in this language: we verify that once the tree-level unitarity is ensured, then the one-loop finiteness of the oblique correction parameters S and U is automatically guaranteed.

    hep-phhep-thPRD(2019)·35 citations
14. 14*

    Quark mass function from a OGE-type interaction in Minkowski space

    Elmar P. Biernat🇵🇹 · Franz Gross🇺🇸 · M. T. Peña🇵🇹 · Alfred Stadler🇵🇹 · Sofia Leitão🇵🇹

    We present results for the quark mass function in Minkowski space calculated from an interaction kernel that consists of an effective one-gluon-exchange and a constant interaction. We analyze the gauge dependence of our results and compare them in the spacelike region to the available lattice QCD data.

    hep-phnucl-thActa Phys.Polon.Supp.(2021)·0 citations
15. 15*

    Exclusive semileptonic decays of $D$ and $D_s$ mesons in the covariant confining quark model

    Mikhail A. Ivanov🇷🇺 · Jürgen G. Körner🇩🇪 · Jignesh N. Pandya🇮🇳 · Pietro Santorelli🇮🇹 · Nakul R. Soni🇮🇳 · Chien-Thang Tran🇮🇹

    Recently, the BESIII collaboration has reported numerous measurements of various $D_{(s)}$ meson semileptonic decays with significantly improved precision. Together with similar studies carried out at BABAR, Belle, and CLEO, new windows to a better understanding of weak and strong interactions in the charm sector have been opened. In light of new experimental data, we review the theoretical description and predictions for the semileptonic decays of $D_{(s)}$ to a pseudoscalar or a vector meson. This review is essentially an extended discussion of our recently published results obtained in the framework of the covariant confining quark model.

    hep-phFront.Phys.(Beijing)(2019)·105 citations
16. 16*

    The Mass Gap Approach to QCD

    Gergely Gábor Barnaföldi🇭🇺 · Vakhtang Gogokhia🇭🇺

    We convincingly argue that the true dynamical and gauge structures of the QCD ground state are much more complicated than its Lagrangian exact gauge symmetry supposes to be. The dynamical source of these complications has been identified with the tadpole/seagull term, which renormalized version called, {\sl the mass gap}. It is explicitly present in the full gluon self-energy. The true dynamical role of the mass gap was hidden in the QCD ground state. To disclose it the splintering between the transverse conditions for the full gluon self-energy and its subtracted counterpart has been derived. We have established the equation of motion for the full gluon propagator on account of the mass gap. It allows to fix the dynamical and gauge structures of the full gluon propagator with a newly-derived generalized gauge. It is uniquely given as a function of the gluon momentum. All this makes it possible to present novel non-perturbative analytical approach to QCD, which we call the mass gap approach. It extends the mass gap concept to be accounted for the QCD ground state as well. We have found the general non-perturbative solution for the full gluon propagator with exactly defined finite gluon pole mass, and it is different from the excitations with the effective gluon masses. Despite the exact gauge symmetry is broken in the ground state, the renormalizability of the theory is not affected due to the important role of the Slavnov-Taylor identity in the renormalization beyond the perturbation theory. For this the non-perturbative multiplicative renormalization program for the full massive gluon propagator has been formulated. Our approach does not allow the massive gluons to be the mass-shell objects, and thus prevents them to appear as physical states at large distances (confinement of massive gluons).

    hep-phhep-thnucl-th3 citations
17. 17*

    New Realization of the Conversion Calculation for Reactor Antineutrino Fluxes

    Yu-Feng Li🇨🇳 · Di Zhang🇨🇳

    Validation of the effective conversion method in the reactor antineutrino flux calculation is examined using the \textit{ab initio} calculation of the electron and antineutrino spectra from the state-of-the-art nuclear database. It turns out that neglecting the shape variation of beta decay branches between the allowed and forbidden transitions would induce significant bias in the total inverse-beta-decay yields and energy spectral distributions. We propose a new realization of the conversion method with both the allowed and forbidden virtual branches, and apply it to both the \textit{simulated} data from the nuclear database and \textit{real} data from the fission measurements at ILL by virtue of statistical properties of the allowed and forbidden decays in the database. Two kinds of dominant uncertainty sources are identified and it turns out that the new realization of the conversion calculation can largely reduce the rate and spectral bias and thus present a reliable prediction of the antineutrino fluxes if accurate beta decay information is available in the high endpoint energy range.

    hep-phhep-exnucl-thPRD(2019)·18 citations
18. 18*

    Master formula for one-loop renormalization of bosonic SMEFT operators

    Gerhard Buchalla🇩🇪 · Alejandro Celis🇩🇪 · Claudius Krause🇺🇸 · Jan-Niklas Toelstede🇩🇪

    Using background-field method and super-heat-kernel expansion, we derive a master formula for the one-loop UV divergences of the bosonic dimension-6 operators in Standard Model Effective Field Theory (SMEFT). This approach reduces the calculation of all the UV divergences to algebraic manipulations. Using this formula we corroborate results in the literature for the one-loop anomalous dimension matrix of SMEFT obtained via diagrammatic methods, considering contributions from the operators $X^3,{\varphi }^6,{\varphi }^4{D}^2,X^2{\varphi }^2$ of the Warsaw basis. The formula is derived in a general way and can be applied to other quantum field theories as well.

    hep-ph26 citations
19. 19*

    Perturbing neutrino oscillations around the solar resonance

    Ivan Martinez-Soler🇺🇸 · Hisakazu Minakata🇺🇸

    Atmospheric neutrinos at low energies, $E\text{lsim}500$ MeV, is known to be a rich source of information of lepton mixing parameters. We formulate a simple perturbative framework to elucidate the characteristic features of neutrino oscillation at around the solar-scale enhancement due to the matter effect. The clearest message we could extract from our perturbation theory is that CP violation in the appearance oscillation probability is large, a factor of $\sim 10$ times larger than CP violation at around the atmospheric-scale oscillation maximum. Underlying mechanism for it is that one of the suppression factors on the CP phase dependent terms due to smallness of $\Delta m_{21}^2/\Delta m_{31}^2$ are dynamically lifted by the solar-scale enhancement. Our framework has a unique feature as a perturbation theory in which large $\Delta m_{31}^2$ term outside the key 1-2 sector for the solar-scale resonance does not yield sizeable corrections. On the contrary, the larger the $\Delta m_{31}^2$, the smaller the higher order corrections.

    hep-phhep-exPTEP(2019)·20 citations
20. 20*

    Geometry of Flat Directions in Scale-Invariant Potentials

    Kristjan Kannike🇪🇪 · Aleksei Kubarski🇪🇪 · Luca Marzola🇪🇪

    We observe that biquadratic potentials admit non-trivial flat directions when the determinant of the quartic coupling matrix of the scalar fields vanishes. This consideration suggests a new approach to the problem of finding flat directions in scale-invariant theories, noticeably simplifying the study of scalar potentials involving many fields. The method generalizes to arbitrary quartic potentials by requiring that the hyperdeterminant of the tensor of scalar couplings be zero. We demonstrate our approach with detailed examples pertaining to common scalar extensions of the Standard Model.

    hep-phPRD(2019)·13 citations
21. 21*

    Imprint of a scalar era on the primordial spectrum of gravitational waves

    Francesco D'Eramo🇮🇹 · Kai Schmitz🇮🇹

    Upcoming searches for the stochastic background of inflationary gravitational waves (GWs) offer the exciting possibility to probe the evolution of our Universe prior to Big Bang nucleosynthesis. In this spirit, we explore the sensitivity of future GW observations to a broad class of beyond-the-Standard-Model scenarios that lead to a nonstandard expansion history. We consider a new scalar field whose coherent oscillations dominate the energy density of the Universe at very early times, resulting in a scalar era prior to the standard radiation-dominated era. The imprint of this scalar era on the primordial GW spectrum provides a means to probe well-motivated yet elusive models of particle physics. Our work highlights the complementarity of future GW observatories across the entire range of accessible frequencies.

    hep-phastro-ph.COgr-qcPhys.Rev.Research.(2019)·84 citations
22. 22*

    Probing Boson Stars with Extreme Mass Ratio Inspirals

    Huai-Ke Guo🇺🇸 · Kuver Sinha🇺🇸 · Chen Sun🇨🇳

    We propose to use gravitational waves from extreme mass ratio inspirals (EMRI), composed of a boson star and a supermassive black hole in the center of galaxies, as a new method to search for boson stars. Gravitational waves from EMRI have the advantage of being long-lasting within the frequency band of future space-based interferometer gravitational wave detectors and can accumulate large signal-to-noise ratio (SNR) for very sub-solar mass boson stars. Compared to gravitational waves from boson star binaries, which fall within the LIGO band, we find that much larger ranges of the mass and compactness of boson stars, as well as the underlying particle physics parameter space, can be probed by EMRI. We take tidal disruption of the boson stars into account and distinguish those which dissolve before the inner-most-stable-circular-orbit (ISCO) and those which dissolve after it. Due to the large number of cycles recorded, EMRIs can lead to a very precise mass determination of the boson star and distinguish it from standard astrophysical compact objects in the event of a signal. Tidal effects in inspiralling binary systems, as well as possible correlated electromagnetic signals, can also serve as potential discriminants.

    hep-phastro-ph.COgr-qcJCAP(2019)·33 citations
23. 23*

    Studies of a thermally averaged p-wave Sommerfeld factor

    Seyong Kim🇰🇷 · M. Laine🇨🇭

    Thermal pair annihilation of heavy particles, such as dark matter or its co-annihilation partners, can be strongly influenced by attractive interactions. We investigate the case that pair annihilation proceeds through a velocity-suppressed $p$-wave operator, in the presence of an SU(3) gauge force. Making use of a non-relativistic effective theory, the thermal average of the pair-annihilation rate is estimated both through a resummed perturbative computation and through lattice simulation, in the range $M/T\sim \mathrm{10...30}$. Bound states contribute to the annihilation process and enhancement factors of up to $\sim 100$ can be found.

    hep-phhep-latPLB(2019)·13 citations
24. 24*

    Type I + II Seesaw in a Two Higgs Doublet Model

    D. Cogollo🇧🇷 · Ricardo D. Matheus🇧🇷 · Tessio B. de Melo🇧🇷 · Farinaldo S. Queiroz🇧🇷

    Two Higgs Doublet Models (2HDM) are popular extensions of the Standard Model for several reasons, but do not explain neutrino masses. In this work, we investigate how one can incorporate neutrino masses within the framework of the 2HDM-U(1), where U(1) is an abelian gauge symmetry used to nicely address the absence of flavor changing neutral currents in 2HDM. In particular, we explore realizations of the type I and type II seesaw since they are mechanisms that we dote on for being able to generate elegantly small active neutrino masses. We show that one can build several models featuring type I, type II and type I+II seesaw mechanism with different phenomenological implications.

    hep-phPLB(2019)·23 citations
25. 25*

    Revisiting the $t\bar{t}hh$ channel at the FCC-hh

    Shankha Banerjee🇬🇧 · Frank Krauss🇬🇧 · Michael Spannowsky🇬🇧

    The exploration of the scalar sector of the Standard Model is at the core of current and future science programs at collider experiments, with increasing focus on the self-interaction of the Higgs boson. This important parameter of the Higgs sector can be measured in various channels, among the production of a Higgs boson associated with a top-quark pair, $\bar{t}thh$. In this paper we study this channel and its potential to measure or constrain the self-coupling and possible new physics contributions at a future 100 TeV proton-proton collider. Analysing this highly complex final state adds to the sensitivity for enhanced self-coupling interactions, and we argue that a measurement of this process is a necessity to constrain blind directions in the multi-dimensional parameter space of well-motivated new physics scenarios.

    hep-phhep-exPRD(2019)·22 citations
26. 26*

    Observational prospects for gravitational waves from hidden or dark chiral phase transitions

    Alexander J. Helmboldt🇩🇪 · Jisuke Kubo🇩🇪 · Susan van der Woude🇩🇪

    We study the gravitational wave (GW) signature of first-order chiral phase transitions ($\chi$PT) in strongly interacting hidden or dark sectors. We do so using several effective models in order to reliably capture the relevant non-perturbative dynamics. This approach allows us to explicitly calculate key quantities characterizing the $\chi$PT without having to resort to rough estimates. Most importantly, we find that the transition's inverse duration $\beta$ normalized to the Hubble parameter $H$ is at least two orders of magnitude larger than typically assumed in comparable scenarios, namely $\beta /H\gtrsim \mathcal{O}(10^4)$. The obtained GW spectra then suggest that signals from hidden $\chi$PTs occurring at around 100 MeV can be in reach of LISA, while DECIGO and BBO may detect a stochastic GW background associated with transitions between roughly 1 GeV and 10 TeV. Signatures of transitions at higher temperatures are found to be outside the range of any currently proposed experiment. Even though predictions from different effective models are qualitatively similar, we find that they may vary considerably from a quantitative point of view, which highlights the need for true first-principle calculations such as lattice simulations.

    hep-phastro-ph.COhep-latPRD(2019)·108 citations
27. 27*

    PolyLogTools - Polylogs for the masses

    Claude Duhr🇨🇭 · Falko Dulat🇺🇸

    We review recent developments in the study of multiple polylogarithms, including the Hopf algebra of the multiple polylogarithms and the symbol map, as well as the construction of single valued multiple polylogarithms and discuss an algorithm for finding fibration bases. We document how these algorithms are implemented in the Mathematica package PolyLogTools and show how it can be used to study the coproduct structure of polylogarithmic expressions and how to compute iterated parametric integrals over polylogarithmic expressions that show up in Feynman integal computations at low loop orders.

    ↳ hep-thhep-phJHEP(2019)·376 citations
28. 28*

    A model of dynamical SUSY breaking

    Jihn E. Kim🇰🇷 · Bumseok Kyae🇰🇷

    Supersymmetric (SUSY) models and dynamical breaking of symmetries have been used to explain hierarchies of mass scales. We find that a chiral representation, $\overline{10}\oplus \overline{5}\oplus 2\cdot 5$ in SUSY SU(5) in the hidden sector, breaks global SUSY dynamically, by producing a composite field $\varphi$ below the SU(5) confinement scale. This dynamincal SUSY breaking can have two important applications, one in particle physics and the other in cosmology. Gavitational effects transmit this dynamical breaking to the standard model(SM) superpartners and the quintessential vacuum energy. The SM superpartners feel the effects just by the magnitude of the gravitino mass while the smallness of the quintessential vacuum energy is due to the composite nature of a singlet field $\varphi$. The composite $\varphi$ carries a global charge which is hardly broken in SUSY and hence its phase can be used toward a quintessential axion for dark energy of the Universe.

    ↳ hep-thastro-ph.COhep-phPLB(2019)·10 citations
29. 29*

    Cooling of the Cassiopeia A neutron star and the effect of diffusive nuclear burning

    Wynn C.G. Ho🇺🇸 · M.J.P. Wijngaarden🇬🇧 · Philip Chang🇺🇸 · Craig O. Heinke🇨🇦 · Dany Page🇲🇽 · Mikhail Beznogov🇲🇽 · Daniel J. Patnaude🇺🇸

    The study of how neutron stars cool over time can provide invaluable insights into fundamental physics such as the nuclear equation of state and superconductivity and superfluidity. A critical relation in neutron star cooling is the one between observed surface temperature and interior temperature. This relation is determined by the composition of the neutron star envelope and can be influenced by the process of diffusive nuclear burning (DNB). We calculate models of envelopes that include DNB and find that DNB can lead to a rapidly changing envelope composition which can be relevant for understanding the long-term cooling behavior of neutron stars. We also report on analysis of the latest temperature measurements of the young neutron star in the Cassiopeia A supernova remnant. The 13 Chandra observations over 18 years show that the neutron star's temperature is decreasing at a rate of 2-3 percent per decade, and this rapid cooling can be explained by the presence of a proton superconductor and neutron superfluid in the core of the star.

    ↳ astro-ph.HEastro-ph.SRhep-phnucl-thAIP Conf.Proc.(2019)·5 citations
30. 30*

    Modular symmetry anomaly in magnetic flux compactification

    Yuki Kariyazono🇯🇵 · Tatsuo Kobayashi🇯🇵 · Shintaro Takada🇯🇵 · Shio Tamba🇯🇵 · Hikaru Uchida🇯🇵

    We study modular symmetry anomalies in four-dimensional low-energy effective field theory, which is derived from six-dimensional supersymmetric $U(N)$ Yang-Mills theory by magnetic flux compactification. The gauge symmetry $U(N)$ is broken to $U(N_a)\times U(N_b)$ by magnetic fluxes. It is found that Abelian subgroup of the modular symmetry corresponding to discrete part of $U(1)$ can be anomalous, but other elements independent of $U(1)$ in the modular symmetry are always anomaly-free.

    ↳ hep-thhep-phPRD(2019)·54 citations
31. 31*

    Radiation beaming in the quantum regime

    T. G. Blackburn🇸🇪 · D. Seipt🇺🇸 · S. S. Bulanov🇺🇸 · M. Marklund🇸🇪

    Classical theories of radiation reaction predict that the electron motion is confined to the plane defined by the electron's instantaneous momentum and the force exerted by the external electromagnetic field. However, in the quantum radiation reaction regime, where the recoil exerted by individual quanta becomes significant, the electron can scatter `out-of-plane', as the photon is emitted into a cone with finite opening angle. We show that Monte Carlo implementation of an angularly resolved emission rate leads to substantially improved agreement with exact QED calculations of nonlinear Compton scattering. Furthermore, we show that the transverse recoil caused by this finite beaming, while negligible in many high-intensity scenarios, can be identified in the increase in divergence, in the plane perpendicular to the polarization, of a high-energy electron beam that interacts with a linearly polarized, ultraintense laser.

    ↳ physics.plasm-phhep-phPRA(2020)·34 citations
32. 32*

    QED corrections to the big-bang nucleosynthesis reaction rates

    Cyril Pitrou🇫🇷 · Maxim Pospelov🇨🇦

    We compute radiative corrections to nuclear reaction rates that determine the outcome of the Big-Bang Nucleosynthesis (BBN). Any nuclear reaction producing a photon with an energy above $2m_e$ must be supplemented by the corresponding reaction where the final state photon is replaced by an electron-positron pair. We find that pair production brings a typical $0.2\%$ enhancement to photon emission rates, resulting in a similar size corrections to elemental abundances. The exception is ${}^4\mathrm{He}$ abundance, which is insensitive to the small changes in the nuclear reaction rates. We also investigate the effect of vacuum polarisation on the Coulomb barrier, which brings a small extra correction when reaction rates are extrapolated from the measured energies to the BBN Gamow peak energies.

    ↳ astro-ph.COhep-phnucl-thPRC(2020)·16 citations
33. 33*

    Cosmological constraints on neutrino self-interactions with a light mediator

    F. Forastieri🇮🇹 · M. Lattanzi🇮🇹 · P. Natoli🇮🇹

    If active neutrinos undergo non-standard (`secret') interactions (NS$\nu$I) the cosmological evolution of the neutrino fluid might be altered, leaving an imprint in cosmological observables. We use the latest publicly available CMB data from Planck to constrain NS$\nu$I inducing $\nu -\nu$ scattering, under the assumption that the mediator $\varphi$ of the secret interaction is very light. We find that the effective coupling constant of the interaction, $g_{\mathrm{eff}}^4\equiv ⟨\sigma v⟩T_{\nu }^2$, is constrained at $<2.35\times 10^{-27}$ (95\% credible interval), which stregthens to $g_{\mathrm{eff}}^4<1.64\times 10^{-27}$ when Planck non-baseline small-scale polarization is considered. Our findings imply that after decoupling at $T\simeq 1$ MeV, cosmic neutrinos are free streaming at redshifts $z>3800$, or $z>2300$ if small-scale polarization is included. These bounds are only marginally improved when data from geometrical expansion probes are included in the analysis to complement Planck. We also find that the tensions between CMB and low-redshift measurements of the expansion rate $H_0$ and the amplitude of matter fluctuations ${\sigma }_8$ are not significantly reduced. Our results are independent on the underlying particle physics model as long as $\varphi$ is very light. Considering a model with Majorana neutrinos and a pseudoscalar mediator we find that the coupling constant $g$ of the secret interaction is constrained at $\lesssim 7\times 10^{-7}$. By further assuming that the pseudoscalar interaction comes from a dynamical realization of the see-saw mechanism, as in Majoron models, we can bound the scale of lepton number breaking $v_{\sigma }$ as $\gtrsim (1.4\times 10^6)m_{\nu }$.

    ↳ astro-ph.COhep-phPRD(2019)·96 citations
34. 34*

    Future CMB constraints on cosmic birefringence and implications for fundamental physics

    Levon Pogosian🇨🇦 · Meir Shimon🇮🇱 · Matthew Mewes🇺🇸 · Brian Keating🇺🇸

    The primary scientific target of the CMB polarization experiments that are currently being built and proposed is the detection of primordial tensor perturbations. As a byproduct, these instruments will significantly improve constraints on cosmic birefringence, or the rotation of the CMB polarization plane. If convincingly detected, cosmic birefringence would be a dramatic manifestation of physics beyond the standard models of particle physics and cosmology. We forecast the bounds on the cosmic polarization rotation (CPR) from the upcoming ground-based Simons Observatory (SO) and the space-based LiteBIRD experiments, as well as a "fourth generation" ground-based CMB experiment like CMB-S4 and the mid-cost space mission PICO. We examine the detectability of both a stochastic anisotropic rotation field and an isotropic rotation by a constant angle. CPR induces new correlations of CMB observables, including spectra of parity-odd type in the case of isotropic CPR, and mode-coupling correlations in the anisotropic rotation case. We find that LiteBIRD and SO will reduce the 1$\sigma$ bound on the isotropic CPR from the current value of 30 arcmin to 1.5 and 0.6 arcmin, respectively, while CMB-S4-like and PICO will reduce it to $\sim 0.1$ arcmin. The bounds on the amplitude of a scale-invariant CPR spectrum will be reduced by 1, 2 and 3 orders of magnitude by LiteBIRD, SO and CMB-S4-like/PICO, respectively. We discuss implications of the forecasted CPR bounds for pseudoscalar fields, primordial magnetic fields (PMF), and violations of Lorentz invariance. We find that CMB-S4-like and PICO can reduce the 1$\sigma$ bound on the amplitude of the scale-invariant PMF from 1 nG to 0.1 nG, while also probing the magnetic field of the Milky Way. They will also significantly improve bounds on the axion-photon coupling, placing stringent constraints on the string theory axions.

    ↳ astro-ph.COhep-phPRD(2019)·71 citations
35. 35*

    A Standard Ruler at Cosmic Dawn

    Julian B. Muñoz🇺🇸

    The matter in our Universe comes in two flavors: dark and baryonic. Of these, only the latter couples to photons, giving rise to the well-known baryon acoustic oscillations and, in the process, generating supersonic relative velocities between dark matter and baryons. These velocities---imprinted with the acoustic scale in their genesis---impede the formation of the first stars during cosmic dawn ($z\sim 20$), modulating the expected 21-cm signal from this era. In a companion paper we showed, combining numerical simulations and analytic models, that this modulation takes the form of robust velocity-induced acoustic oscillations (VAOs), with a well-understood shape that is frozen at recombination, and unaffected by the unknown astrophysics of star formation. Here we propose using these VAOs as a standard ruler at cosmic dawn. We find that three years of 21-cm power-spectrum data from the upcoming HERA interferometer should be able to measure the Hubble expansion rate $H(z)$ at $z=15-20$ to percent-level precision, ranging from $0.3\%$ to $11\%$ depending on the strength of astrophysical feedback processes and foregrounds. This would provide a new handle on the expansion rate of our Universe during an otherwise unprobed epoch, opening a window to the mysterious cosmic-dawn era.

    ↳ astro-ph.COhep-phPRL(2019)·72 citations
36. 36*

    Self-Interacting Dark Matter Subhalos in the Milky Way's Tides

    Omid Sameie🇺🇸 · Hai-Bo Yu🇺🇸 · Laura V. Sales🇺🇸 · Mark Vogelsberger🇺🇸 · Jesus Zavala🇮🇸

    We study evolution of self-interacting dark matter (SIDM) subhalos in the Milky Way (MW) tidal field. The interaction between the subhalos and the MW's tides lead to more diverse dark matter distribution in the inner region, compared to their cold dark matter counterparts. We test this scenario with two MW satellite galaxies, Draco and Fornax, opposite extremes in the inner dark matter content, and find that they can be accommodated within the SIDM model proposed to explain the diverse rotation curves of spiral galaxies in the field.

    ↳ astro-ph.GAhep-phPRL(2020)·127 citations
37. 37*

    Cosmological constant: relaxation vs multiverse

    Alessandro Strumia🇮🇹 · Daniele Teresi🇮🇹

    We consider a scalar field with a bottom-less potential, such as $g^3\varphi$, finding that cosmologies unavoidably end up with a crunch, late enough to be compatible with observations if $g\lesssim 1.2H_0^{2/3}{M}_{\mathrm{Pl}}^{1/3}$. If rebounces avoid singularities, the multiverse acquires new features; in particular probabilities avoid some of the usual ambiguities. If rebounces change the vacuum energy by a small enough amount, this dynamics selects a small vacuum energy and becomes the most likely source of universes with anthropically small cosmological constant. Its probability distribution could avoid the gap by 2 orders of magnitude that seems left by standard anthropic selection.

    ↳ gr-qcastro-ph.COhep-phhep-thPLB(2019)·7 citations
38. 38*

    Renormalisation group improvement in the stochastic formalism

    Robert J. Hardwick🇬🇧 · Tommi Markkanen🇬🇧 · Sami Nurmi🇫🇮

    We investigate compatibility between the stochastic infrared (IR) resummation of light test fields on inflationary spacetimes and renormalisation group running of the ultra-violet (UV) physics. Using the Wilsonian approach, we derive improved stochastic Langevin and Fokker-Planck equations which consistently include the renormalisation group effects. With the exception of stationary solutions, these differ from the naive approach of simply replacing the classical potential in the standard stochastic equations with the renormalisation group improved potential. Using this new formalism, we exemplify the IR dynamics with the Yukawa theory during inflation, illustrating the differences between the consistent implementation of the UV running and the naive approach.

    ↳ hep-thgr-qchep-phJCAP(2019)·19 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.