Mon·Jun 22, 2020Monday·June 22, 2020

1. 01*

   Texture of Single Vanishing Subtrace in Neutrino Mass Matrix

   A. Ismael (1)🇪🇬 · M. AlKhateeb (2)🇫🇷 · N. Chamoun (3)🇸🇾 · E. I. Lashin (1 and 4) ((1) Ain Shams-Egypt, (2) Cergy Pontoise-France, (3) HIAST-Syria, (4) Zewail City-Egypt)🇪🇬

   We consider a texture for the neutrino mass matrix characterized by one vanishing $2\times 2$ subtrace. We analyze phenomenologically and analytically all the six possible patterns, and show that all non-singular ones are able to accommodate the experimental bounds, whereas singular patterns allow only for four inverted-hierarchy type textures. We then present some possible realizations of this texture, within seesaw scenarios, either directly or indirectly by relating it to zero-textures.

   hep-phPRD(2021)·6 citations
2. 02*

   Master Integrals for two-loop QCD corrections to Quasi PDFs

   Long-Bin Chen🇨🇳 · Wei Wang🇨🇳 · Ruilin Zhu🇨🇳

   We compute the master integrals for two-loop QCD corrections to quasi parton distribution functions (PDFs) in large momentum effective theory. Analytical results of the master integrals are derived using the method of differential equations, along with a proper choice of canonical basis. The results of master integrals are expressed in terms of Goncharov polylogarithms. These integrals allow to extract the two-loop short-distance matching coefficients between quasi and light cone PDFs in large momentum effective theory, and are helpful to extract the nucleon PDFs from first principles.

   hep-phhep-latnucl-thJHEP(2020)·35 citations
3. 03*

   Two-loop renormalisation of gauge theories in $4D$ Implicit Regularisation and connections to dimensional methods

   A. Cherchiglia🇧🇷 · D. C. Arias-Perdomo🇧🇷 · A. R. Vieira🇧🇷 · M. Sampaio🇧🇷 · B. Hiller🇵🇹

   We compute the two-loop $\beta$-function of scalar and spinorial quantum electrodynamics as well as pure Yang-Mills and quantum chromodynamics using the background field method in a fully quadridimensional setup using Implicit Regularization (IREG). Moreover, a thorough comparison with dimensional approaches such as conventional dimensional regularization (CDR) and dimensional reduction (DRED) is presented. Subtleties related to Lorentz algebra contractions/symmetric integrations inside divergent integrals as well as renormalisation schemes are carefully discussed within IREG where the renormalisation constants are fully defined as basic divergent integrals to arbitrary loop order. Moreover, we confirm the hypothesis that momentum routing invariance in the loops of Feynman diagrams implemented via setting well-defined surface terms to zero deliver non-abelian gauge invariant amplitudes within IREG just as it has been proven for abelian theories.

   hep-phhep-thEPJC(2021)·20 citations
4. 04*

   Electron-positron annihilation to photons at $O({\alpha }^3)$ revisited

   Roman N. Lee🇷🇺

   We apply the modern multiloop methods to the calculation of the total cross sections of electron-positron annihilation to 2 and 3 photons exactly in $s/m^2$ with the accuracy $O({\alpha }^3)$. Examining the asymptotics of our results, we find agreement with Ref. [Andreassi_et_al_1962] and discover mistakes in the results of Refs. [Eidelman&Kuraev_1978,Berends&Kleiss_1981]. This mistake is due to the terms, omitted in differential cross section in Refs. \[Eidelman&Kuraev_1978,Berends&Kleiss_1981], which are peaked in the kinematic region with all three photons being quasi-parallel to the collision axis. After restoring these terms, we find an agreement of the corrected result of Ref. [Berends&Kleiss_1981] with our result.

   hep-phNPB(2020)·9 citations
5. 05*

   Revisiting the proton mass decomposition

   Andreas Metz🇺🇸 · Barbara Pasquini🇮🇹 · Simone Rodini🇮🇹

   Different decompositions (sum rules) for the proton mass have been proposed in the literature. All of them are related to the energy-momentum tensor in quantum chromodynamics. We review and revisit these decompositions by paying special attention to recent developments with regard to the renormalization of the energy-momentum tensor. The connection between the sum rules is discussed as well. We present numerical results for the various terms of the mass decompositions up to 3 loops in the strong coupling, and consider their scheme dependence. We also elaborate on the role played by the trace anomaly and the sigma terms.

   hep-phhep-latnucl-thPRD(2021)·100 citations
6. 06*

   Angular and polarization observables for Majorana-mediated B decays with effective interactions

   Lucía Duarte🇺🇾 · Gabriel Zapata🇦🇷 · O.A. Sampayo🇦🇷

   We probe the effective field theory extending the Standard Model with a sterile neutrino in B meson decays at B factories and lepton colliders, using angular and polarization observables. We put bounds on different effective operators characterized by their distinct Dirac-Lorentz structure, and probe the $N$-mediated B decays sensitivity to these interactions. We define a Forward-Backward asymmetry $A_{FB}^{\ell \gamma }$ between the muon and photon directions for the $B\to \mu \nu \gamma$ decay, which allows us to separate the SM contribution from the effective lepton number conserving and violating processes, mediated by a near on-shell $N$. Using the most stringent constraints on the effective parameter space from Belle and BaBar we find that a measurement of the final polarization $P_{\tau }$ in the rare $B^{-}\to {\ell }_1^{-}{\ell }_2^{-}{\pi }^{+}$ decays can help us infer the scalar or vector interaction content in the $N$ production or decay vertices. We find that the B meson decays are more sensitive to scalar operators.

   hep-phEPJC(2020)·15 citations
7. 07*

   Causal representation of multi-loop Feynman integrands within the loop-tree duality

   J. Jesus Aguilera-Verdugo🇪🇸 · Roger J. Hernandez-Pinto🇲🇽 · German Rodrigo🇪🇸 · German F. R. Sborlini🇪🇸 · William J. Torres Bobadilla🇪🇸

   The numerical evaluation of multi-loop scattering amplitudes in the Feynman representation usually requires to deal with both physical (causal) and unphysical (non-causal) singularities. The loop-tree duality (LTD) offers a powerful framework to easily characterise and distinguish these two types of singularities, and then simplify analytically the underling expressions. In this paper, we work explicitly on the dual representation of multi-loop Feynman integrals generated from three parent topologies, which we refer to as Maximal, Next-to-Maximal and Next-to-Next-to-Maximal loop topologies. In particular, we aim at expressing these dual contributions, independently of the number of loops and internal configurations, in terms of causal propagators only. Thus, providing very compact and causal integrand representations to all orders. In order to do so, we reconstruct their analytic expressions from numerical evaluation over finite fields. This procedure implicitly cancels out all unphysical singularities. We also interpret the result in terms of entangled causal thresholds. In view of the simple structure of the dual expressions, we integrate them numerically up to four loops in integer space-time dimensions, taking advantage of their smooth behaviour at integrand level.

   hep-phhep-thJHEP(2021)·61 citations
8. 08*

   Solar neutrino probes of the muon anomalous magnetic moment in the gauged $U(1{)}_{L_{\mu }-L_{\tau }}$

   Dorian Warren Praia do Amaral🇬🇧 · David G. Cerdeno🇬🇧 · Patrick Foldenauer🇬🇧 · Elliott Reid🇬🇧

   Models of gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ can provide a solution to the long-standing discrepancy between the theoretical prediction for the muon anomalous magnetic moment and its measured value. The extra contribution is due to a new light vector mediator, which also helps to alleviate an existing tension in the determination of the Hubble parameter. In this article, we explore ways to probe this solution via the scattering of solar neutrinos with electrons and nuclei in a range of experiments and considering high and low solar metallicity scenarios. In particular, we reevaluate Borexino constraints on neutrino-electron scattering, finding them to be more stringent than previously reported, and already excluding a part of the $(g-2{)}_{\mu }$ explanation with mediator masses smaller than $2\times 10^{-2}$ GeV. We then show that future direct dark matter detectors will be able to probe most of the remaining solution. Due to its large exposure, LUX-ZEPLIN will explore regions with mediator masses up to $5\times 10^{-2}$ GeV and DARWIN will be able to extend the search beyond $10^{-1}$ GeV, thereby covering most of the area compatible with $(g-2{)}_{\mu }$. For completeness, we have also computed the constraints derived from the recent XENON1T electron recoil search and from the CENNS-10 LAr detector, showing that none of them excludes new areas of the parameter space. Should the excess in the muon anomalous magnetic moment be confirmed, our work suggests that direct detection experiments could provide crucial information with which to test the $U(1{)}_{L_{\mu }-L_{\tau }}$ solution, complementary to efforts in neutrino experiments and accelerators.

   hep-phastro-ph.COJHEP(2020)·97 citations
9. 09*

   2020 Global reassessment of the neutrino oscillation picture

   P. F. de Salas🇸🇪 · D. V. Forero🇨🇴 · S. Gariazzo🇪🇸 · P. Martínez-Miravé🇪🇸 · O. Mena🇪🇸 · C. A. Ternes🇮🇹 · M. Tórtola🇪🇸 · J. W. F. Valle🇪🇸

   We present an updated global fit of neutrino oscillation data in the simplest three-neutrino framework. In the present study we include up-to-date analyses from a number of experiments. Concerning the atmospheric and solar sectors, we give updated analyses of DeepCore and SNO data, respectively. We have also included the latest electron antineutrino data collected by the Daya Bay and RENO reactor experiments, and the long-baseline T2K and NO$\nu$A measurements. These new analyses result in more accurate measurements of ${\theta }_{13}$, ${\theta }_{12}$, $\Delta m_{21}^2$ and $|\Delta m_{31}^2|$. The best fit value for the atmospheric angle ${\theta }_{23}$ lies in the second octant, but first octant solutions remain allowed at $\sim 2.4\sigma$. Regarding CP violation measurements, the preferred value of $\delta$ we obtain is 1.08$\pi$ (1.58$\pi$) for normal (inverted) neutrino mass ordering. The global analysis prefers normal neutrino mass ordering with 2.5$\sigma$. This preference is milder than the one found in previous global analyses. The new results should be regarded as robust due to the agreement found between our Bayesian and frequentist approaches. Taking into account only oscillation data, there is a weak/moderate preference for the normal neutrino mass ordering of $2.00\sigma$. While adding neutrinoless double beta decay from the latest Gerda, CUORE and KamLAND-Zen results barely modifies this picture, cosmological measurements raise the preference to $2.68\sigma$ within a conservative approach. A more aggressive data set combination of cosmological observations leads to a similar preference, namely $2.70\sigma$. This very same cosmological data set provides $2\sigma$ upper limits on the total neutrino mass corresponding to $\sum \nu <0.12$ ($0.15$)~eV for normal (inverted) neutrino mass ordering.

   hep-phastro-ph.COhep-exJHEP(2021)·960 citations
10. 10*

    Hidden Photon Dark Matter in the Light of XENON1T and Stellar Cooling

    Gonzalo Alonso-Álvarez🇩🇪 · Fatih Ertas🇩🇪 · Joerg Jaeckel🇩🇪 · Felix Kahlhoefer🇩🇪 · Lennert J. Thormaehlen🇩🇪

    The low-energy electronic recoil spectrum in XENON1T provides an intriguing hint for potential new physics. At the same time, observations of horizontal branch stars favor the existence of a small amount of extra cooling compared to the one expected from the Standard Model particle content. In this note, we argue that a hidden photon with a mass of $\sim 2.5$ keV and a kinetic mixing of $\sim 10^{-15}$ allows for a good fit to both of these excesses. In this scenario, the signal detected in XENON1T is due to the absorption of hidden photon dark matter particles, whereas the anomalous cooling of horizontal branch stars arises from resonant production of hidden photons in the stellar interior.

    hep-phastro-ph.COhep-exJCAP(2020)·109 citations
11. 11*

    Light new physics in XENON1T

    Celine Boehm🇦🇺 · David G. Cerdeno🇪🇸 · Malcolm Fairbairn🇬🇧 · Pedro A. N. Machado🇺🇸 · Aaron C. Vincent🇨🇦

    We examine the recently-reported low-energy electron recoil spectrum observed at the XENON1T underground dark matter direct detection experiment, in the context of new interactions with solar neutrinos. In particular we show that scalar and vector mediators with masses $\lesssim 50$ keV coupled to leptons could already leave a visible signature in the XENON1T experiment, similar to the observed peak below 7 keV. This signals that dark matter detectors are already competing with neutrino scattering experiments such as GEMMA, CHARM-II and Borexino. If these results from XENON1T are interpreted as a new signal of such physics, the parameters which fit the excess face challenges from astrophysics which seem very difficult to overcome. If they are rather viewed as a constraint on new couplings, they herald the start of an era of novel precise probes of physics beyond the standard model with dark matter detectors.

    hep-phPRD(2020)·111 citations
12. 12*

    Boosted Dark Matter Interpretation of the XENON1T Excess

    Bartosz Fornal🇺🇸 · Pearl Sandick🇺🇸 · Jing Shu🇨🇳 · Meng Su🇨🇳 · Yue Zhao🇺🇸

    We propose boosted dark matter (BDM) as a possible explanation for the excess of keV electron recoil events observed by XENON1T. BDM particles have velocities much larger than those typical of virialized dark matter, and, as such, BDM-electron scattering can naturally produce keV electron recoils. We show that the required BDM-electron scattering cross sections can be easily realized in a simple model with a heavy vector mediator. Though these cross sections are too large for BDM to escape from the Sun, the BDM flux can originate from the Galactic Center or from halo dark matter annihilations. Furthermore, a daily modulation of the BDM signal will be present, which could not only be used to differentiate it from various backgrounds, but would also provide important directional information for the BDM flux.

    hep-phPRL(2020)·127 citations
13. 13*

    Higgs Potential from Weyl Conformal Gravity

    Ichiro Oda🇯🇵

    We consider Weyl's conformal gravity coupled to a complex matter field in Weyl geometry. It is shown that a Higgs potential naturally arises from a ${\tilde{R}}^2$ term in moving from the Jordan frame to the Einstein frame. A massless Nambu-Goldstone boson, which stems from spontaneous symmetry breakdown of the Weyl gauge invariance, is absorbed into the Weyl gauge field, thereby the gauge field becoming massive. We present a model where the gravitational interaction generates a Higgs potential whose form is a perfect square. Finally, we show that a theory in the Jordan frame is gauge-equivalent to the corresponding theory in the Einstein frame via the BRST formalism.

    ↳ hep-thgr-qchep-phMod.Phys.Lett.A(2020)·10 citations
14. 14*

    Particle production induced by vacuum decay in real time dynamics

    Soichiro Hashiba🇯🇵 · Yusuke Yamada🇯🇵 · Jun'ichi Yokoyama🇯🇵

    We discuss particle production associated with vacuum decay, which changes the mass of a scalar field coupled to a background field which induces the decay. By utilizing the Stokes phenomenon, we can optimally track the time-evolution of mode function and hence calculate particle production properly. In particular, we use real time formalisms for vacuum decay in Minkowski and de Sitter spacetime together with the Stokes phenomenon method. For each case, we consider the flyover vacuum decay model and stochastic inflation, respectively. Within the real time formalism, the particle production can be viewed as that caused by nontrivial external fields. This gives us a novel perspective of the real time formalism of vacuum decay.

    ↳ hep-thgr-qchep-phPRD(2021)·17 citations
15. 15*

    Gapped dilatons in scale invariant superfluids

    Riccardo Argurio🇧🇪 · Carlos Hoyos🇪🇸 · Daniele Musso🇪🇸 · Daniel Naegels🇧🇪

    We study a paradigmatic model in field theory where a global $U(1)$ and scale symmetries are jointly and spontaneously broken. At zero density the model has a non-compact flat direction, which at finite density needs to be slightly lifted. The resulting low-energy spectrum is composed by a standard gapless $U(1)$ Nambu-Goldstone mode and a light dilaton whose gap is determined by the chemical potential and corrected by the couplings. Even though $U(1)$ and scale symmetries commute, there is a mixing between the $U(1)$ Nambu-Goldstone and the dilaton that is crucial to recover the expected dynamics of a conformal fluid and leads to a phonon propagating at the speed of sound. The results rely solely on an accurate study of the Ward-Takahashi identities and are checked against standard fluctuation computations. We extend our results to a boosted superfluid, and comment the relevance of our findings to condensed matter applications.

    ↳ hep-thcond-mat.quant-gascond-mat.str-elhep-phPRD(2020)·5 citations
16. 16*

    Operator evolution from the similarity renormalization group and the Magnus expansion

    A.J. Tropiano🇺🇸 · S.K. Bogner🇺🇸 · R.J. Furnstahl🇺🇸

    The Magnus expansion is an efficient alternative to solving similarity renormalization group (SRG) flow equations with high-order, memory-intensive ordinary differential equation solvers. The numerical simplifications it offers for operator evolution are particularly valuable for in-medium SRG calculations, though challenges remain for difficult problems involving intruder states. Here we test the Magnus approach in an analogous but more accessible situation, which is the free-space SRG treatment of the spurious bound-states arising from a leading-order chiral effective field theory (EFT) potential with very high cutoffs. We show that the Magnus expansion passes these tests and then use the investigations as a springboard to address various aspects of operator evolution that have renewed relevance in the context of the scale and scheme dependence of nuclear processes. These aspects include SRG operator flow with band- versus block-diagonal generators, universality for chiral EFT Hamiltonians and associated operators with different regularization schemes, and the impact of factorization arising from scale separation. Implications for short-range correlations physics and the possibilities for reconciling high- and low-resolution treatments of nuclear structure and reactions are discussed.

    ↳ nucl-thhep-phnucl-exPRC(2020)·10 citations
17. 17*

    Constraining Early Dark Energy with Large-Scale Structure

    Mikhail M. Ivanov🇺🇸 · Evan McDonough🇺🇸 · J. Colin Hill🇺🇸 · Marko Simonović🇨🇭 · Michael W. Toomey🇺🇸 · Stephon Alexander🇺🇸 · Matias Zaldarriaga🇺🇸

    An axion-like field comprising $\sim 10\%$ of the energy density of the universe near matter-radiation equality is a candidate to resolve the Hubble tension; this is the "early dark energy" (EDE) model. However, as shown in Hill et al. (2020), the model fails to simultaneously resolve the Hubble tension and maintain a good fit to both cosmic microwave background (CMB) and large-scale structure (LSS) data. Here, we use redshift-space galaxy clustering data to sharpen constraints on the EDE model. We perform the first EDE analysis using the full-shape power spectrum likelihood from the Baryon Oscillation Spectroscopic Survey (BOSS), based on the effective field theory (EFT) of LSS. The inclusion of this likelihood in the EDE analysis yields a $25\%$ tighter error bar on $H_0$ compared to primary CMB data alone, yielding $H_0=68.54_{-0.95}^{+0.52}$ km/s/Mpc ($68\%$ CL). In addition, we constrain the maximum fractional energy density contribution of the EDE to $f_{\mathrm{EDE}}<0.072$ ($95\%$ CL). We explicitly demonstrate that the EFT BOSS likelihood yields much stronger constraints on EDE than the standard BOSS likelihood. Including further information from photometric LSS surveys,the constraints narrow by an additional $20\%$, yielding $H_0=68.73_{-0.69}^{+0.42}$ km/s/Mpc ($68\%$ CL) and $f_{\mathrm{EDE}}<0.053$ ($95\%$ CL). These bounds are obtained without including local-universe $H_0$ data, which is in strong tension with the CMB and LSS, even in the EDE model. We also refute claims that MCMC analyses of EDE that omit SH0ES from the combined dataset yield misleading posteriors. Finally, we demonstrate that upcoming Euclid/DESI-like spectroscopic galaxy surveys can greatly improve the EDE constraints. We conclude that current data preclude the EDE model as a resolution of the Hubble tension, and that future LSS surveys can close the remaining parameter space of this model.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2020)·299 citations
18. 18*

    One residue to rule them all: Electroweak symmetry breaking, inflation and field-space geometry

    Georgios K.Karananas🇩🇪 · Marco Michel🇩🇪 · Javier Rubio🇫🇮

    We point out that the successful generation of the electroweak scale via gravitational instanton configurations in certain scalar-tensor theories can be viewed as the aftermath of a simple requirement: the existence of a quadratic pole with a sufficiently small residue in the Einstein-frame kinetic term for the Higgs field. In some cases, the inflationary dynamics may also be controlled by this residue and therefore related to the Fermi-to-Planck mass ratio, up to possible uncertainties associated with the instanton regularization. We present here a unified framework for this hierarchy generation mechanism, showing that the aforementioned residue can be associated with the curvature of the Einstein-frame target manifold in models displaying spontaneous breaking of dilatations. Our findings are illustrated through examples previously considered in the literature.

    ↳ hep-thastro-ph.COgr-qchep-phPLB(2020)·25 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.