Mon·Feb 26, 2018Monday·February 26, 2018

1. 01*

   Testing dark decays of baryons in neutron stars

   Gordon Baym🇺🇸 · D. H. Beck🇺🇸 · Peter Geltenbort🇫🇷 · Jessie Shelton🇺🇸

   We demonstrate that the observation of neutron stars with masses greater than one solar mass places severe demands on any exotic neutron decay mode that could explain the discrepancy between beam and bottle measurements of the neutron lifetime. If the neutron can decay to a stable, feebly-interacting dark fermion, the maximum possible mass of a neutron star is 0.7 solar masses, while all well-measured neutron star masses exceed one solar mass. The survival of $2M_{\odot }$ neutron stars therefore indicates that any explanation beyond the Standard Model for the neutron lifetime puzzle requires dark matter to be part of a multi-particle dark sector with highly constrained interactions.

   hep-phastro-ph.HEnucl-thPRL(2018)·123 citations
2. 02*

   Future DUNE constraints on EFT

   Adam Falkowski🇫🇷 · Giovanni Grilli di Cortona🇧🇷 · Zahra Tabrizi🇧🇷

   In the near future, fundamental interactions at high-energy scales may be most efficiently studied via precision measurements at low energies. A universal language to assemble and interpret precision measurements is the so-called SMEFT, which is an effective field theory (EFT) where the Standard Model (SM) Lagrangian is extended by higher-dimensional operators. In this paper we investigate the possible impact of the DUNE neutrino experiment on constraining the SMEFT. The unprecedented neutrino flux offers an opportunity to greatly improve the current limits via precision measurements of the trident production and neutrino scattering off electrons and nuclei in the DUNE near detector. We quantify the DUNE sensitivity to dimension-6 operators in the SMEFT Lagrangian, and find that in some cases operators suppressed by an O(30) TeV scale can be probed. We also compare the DUNE reach to that of future experiments involving atomic parity violation and polarization asymmetry in electron scattering, which are sensitive to an overlapping set of SMEFT parameters.

   hep-phJHEP(2018)·33 citations
3. 03*

   Dirac-Phase Thermal Leptogenesis in the extended Type-I Seesaw Model

   Matthew J. Dolan🇦🇺 · Tomasz P. Dutka🇦🇺 · Raymond R. Volkas🇦🇺

   Motivated by the fact that the Dirac phase in the PMNS matrix is the only CP-violating parameter in the leptonic sector that can be measured in neutrino oscillation experiments, we examine the possibility that it is the dominant source of CP violation for leptogenesis caused by the out-of-equilibrium decays of heavy singlet fermions. We do so within a low-scale extended type-I seesaw model, featuring two Standard Model singlet fermions per family, in which lepton number is approximately conserved such that the heavy singlet neutrinos are pseudo-Dirac. We find that this produces a predictive model of leptogenesis. Our results show that for low-scale thermal leptogenesis, a pure inverse-seesaw scenario fails to produce the required asymmetry, even accounting for resonance effects, because wash-out processes are too efficient. Dirac-phase leptogenesis is, however, possible when the linear seesaw term is switched on, with the aid of the resonance contributions naturally present in the model. Degenerate and hierarchical spectra are considered -- both can achieve Dirac-phase leptogenesis, although the latter is more constrained. Finally, although unable to probe the parameter space of Dirac-phase leptogenesis, the contributions to unitarity violation of the PMNS matrix, collider constraints and charged-lepton flavour-violating processes are calculated and we further estimate the impact of the future experiments MEG-II and COMET for such models.

   hep-phJCAP(2018)·55 citations
4. 04*

   New Bounds on Axion-Like Particles From the Fermi Large Area Telescope observation of PKS $2155-304$

   Cun Zhang🇨🇳 · Yun-Feng Liang🇨🇳 · Shang Li🇨🇳 · Neng-Hui Liao🇨🇳 · Lei Feng🇨🇳 · Qiang Yuan🇨🇳 · Yi-Zhong Fan🇨🇳 · Zhong-Zhou Ren🇨🇳

   The axion-like particle (ALP)-photon mixing in the magnetic field around $\gamma$-ray sources or along the line-of-sight could induce oscillation between photons and ALPs, which then causes irregularities in the $\gamma$-ray spectra. In this work we try to search for such spectral irregularities in the spectrum of PKS $2155-304$ using 8.6 years of the Fermi Large Area Telescope (Fermi-LAT) data. No significant evidence for the presence of ALP-photon oscillation is obtained, and the parameter space of ALPs is constrained. The exclusion region sensitively depends on the poorly known magnetic field of host galaxy cluster of PKS $2155-304$. If the magnetic field is as high as $\sim 10\mu \mathrm{G}$, the "hole"-like parameter region allowed in Ref.~\cite{Fermi} can be ruled out.

   hep-phastro-ph.HEPRD(2018)·66 citations
5. 05*

   A femtoscopic Correlation Analysis Tool using the Schrödinger equation (CATS)

   D.L. Mihaylov🇩🇪 · V. Mantovani Sarti🇩🇪 · O.W. Arnold🇩🇪 · L. Fabbietti🇩🇪 · B. Hohlweger🇩🇪 · A.M. Mathis🇩🇪

   We present a new analysis framework called "Correlation Analysis Tool using the Schrödinger equation" (CATS) which computes the two-particle femtoscopy correlation function $C(k)$, with $k$ being the relative momentum for the particle pair. Any local interaction potential and emission source function can be used as an input and the wave function is evaluated exactly. In this paper we present a study on the sensitivity of $C(k)$ to the interaction potential for different particle pairs: p-p, p-$\mathrm{\Lambda }$, ${\mathrm{K}}^{-}$-p, ${\mathrm{K}}^{+}$-p, p-${\mathrm{\Xi }}^{-}$ and $\mathrm{\Lambda }$-$\mathrm{\Lambda }$. For the p-p Argonne $v_{18}$ and Reid Soft-Core potentials have been tested. For the other pair systems we present results based on strong potentials obtained from effective Lagrangians such as $\chi$EFT for p-$\mathrm{\Lambda }$, Jülich models for $\mathrm{K}(\bar{\mathrm{K}})$-N and Nijmegen models for $\mathrm{\Lambda }$-$\mathrm{\Lambda }$. For the p-${\mathrm{\Xi }}^{-}$ pairs we employ the latest lattice results from the HAL QCD collaboration. Our detailed study of different interacting particle pairs as a function of the source size and different potentials shows that femtoscopic measurements can be exploited in order to constrain the final state interactions among hadrons. In particular, small collision systems of the order of 1~fm, as produced in pp collisions at the LHC, seem to provide a suitable environment for quantitative studies of this kind.

   hep-phhep-exnucl-exnucl-thEPJC(2018)·125 citations
6. 06*

   Exclusive vector meson photoproduction with proton dissociation in photon-hadron interactions at the LHC

   V. P. Goncalves🇧🇷 · F. S. Navarra🇧🇷 · D. Spiering🇧🇷

   At forward rapidities and high energies we expect to probe the non-linear regime of Quantum Chromodynamics (QCD). One of the most promising observables to constrain the QCD dynamics in this regime is exclusive vector meson photoproduction (EVMP). We study the EVMP in association with a leading baryon (product of the proton dissociation) in photon-hadron interactions that take place in $pp$ and $p$Pb collisions at large impact parameters. We present the rapidity distributions for $\rho$ and $J/\psi$ photoproduction in association with a leading baryon (neutron and delta states) at LHC run 2 energies. Our results show that the $V+\Delta$ cross section is almost 30 % of the $V+n$ one. Our results also show that a future experimental analysis of these processes is, in principle, feasible and can be useful to study the leading particle production.

   hep-phhep-ex0 citations
7. 07*

   Soft gluon evolution and non-global logarithms

   René Ángeles Martínez🇵🇱 · Matthew De Angelis🇬🇧 · Jeffrey R. Forshaw🇬🇧 · Simon Plätzer🇦🇹 · Michael H. Seymour🇬🇧

   We consider soft-gluon evolution at the amplitude level. Our evolution includes Coulomb exchanges and applies to generic hard-scattering processes involving any number of coloured partons. We emphasise the special role played by a Lorentz-invariant evolution variable, which coincides with the transverse momentum of the latest emission in a suitably defined dipole zero-momentum frame. We also relate the evolution algorithm, which was used originally in the derivation of super-leading logarithms, to renormalization group evolution equations that have been encountered recently. Handling large colour matrices presents the most significant challenge to numerical implementations and we present a means to expand systematically about the leading colour approximation.

   hep-phJHEP(2018)·99 citations
8. 08*

   Asymptotic safety in the dark

   Astrid Eichhorn🇩🇪 · Aaron Held🇩🇪 · Peter Vander Griend🇩🇪

   We explore the Renormalization Group flow of massive uncharged fermions -- a candidate for dark matter -- coupled to a scalar field through a Higgs portal. We find that fermionic fluctuations can lower the bound on the scalar mass that arises from vacuum stability. Further, we discuss that despite the perturbative nonrenormalizability of the model, it could be ultraviolet complete at an asymptotically safe fixed point. In our approximation, this simple model exhibits two mechanisms for asymptotic safety: a balance of fermionic and bosonic fluctuations generates a fixed point in the scalar self-interaction; asymptotic safety in the portal coupling is triggered through a balance of canonical scaling and quantum fluctuations. As a consequence of asymptotic safety in the dark sector, the low-energy value of the portal coupling could become a function of the dark fermion mass and the scalar mass, thereby reducing the viable parameter space of the model.

   hep-phhep-thJHEP(2018)·15 citations
9. 09*

   Scalar dark matter search from the extended $\nu$THDM

   Seungwon Baek🇰🇷 · Arindam Das🇰🇷 · Takaaki Nomura🇰🇷

   We consider a neutrino Two Higgs Doublet Model ($\nu$THDM) in which neutrinos obtain {\it naturally} small Dirac masses from the soft symmetry breaking of a global $U(1{)}_X$ symmetry. We extended the model so the soft term is generated by the spontaneous breaking of $U(1{)}_X$ by a new scalar field. The symmetry breaking pattern can also stabilize a scalar dark matter candidate. After constructing the model, we study the phenomenology of the dark matter: relic density, direct and indirect detection.

   hep-phhep-exJHEP(2018)·8 citations
10. 10*

    Electroweak Logarithms in Inclusive Cross Sections

    Aneesh V. Manohar🇺🇸 · Wouter J. Waalewijn🇳🇱

    We develop the framework to perform all-orders resummation of electroweak logarithms of Q/M for inclusive scattering processes at energies Q much above the electroweak scale M. We calculate all ingredients needed at next-to-leading logarithmic (NLL) order and provide an explicit recipe to implement this for 2 $\to$ 2 processes. PDF evolution including electroweak corrections, which lead to Sudakov double logarithms, is computed. If only the invariant mass of the final state is measured, all electroweak logarithms can be resummed by the PDF evolution, at least to LL. However, simply identifying a lepton in the final state requires the corresponding fragmentation function and introduces angular dependence through the exchange of soft gauge bosons. Furthermore, we show the importance of polarization effects for gauge bosons, due to the chiral nature of SU(2) - even the gluon distribution in an unpolarized proton becomes polarized at high scales due to electroweak effects. We justify our approach with a factorization analysis, finding that the objects entering the factorization theorem do not need to be SU(2) $\times$ U(1) gauge singlets, even though we perform the factorization and resummation in the symmetric phase. We also discuss a range of extensions, including jets and how to calculate the EW logarithms when you are fully exclusive in the central (detector) region and fully inclusive in the forward (beam) regions.

    hep-phJHEP(2018)·52 citations
11. 11*

    Large-N_c sum rules for charmed baryons at subleading orders

    Yonggoo Heo🇹🇭 · Matthias F.M. Lutz🇩🇪

    Sum rules for the low-energy constants of the chiral SU(3) Lagrangian with charmed baryons of spin J^P=1/2^+ and J^P=3/2^+ baryons are derived from large-N_c QCD. We consider the large-$N_c$ operator expansion at subleading orders for current-current correlation functions in the charmed baryon-ground states for two scalar and two axial-vector currents.

    hep-phPRD(2018)·5 citations
12. 12*

    Lambda, the Fifth Foundational Constant Considered by Einstein

    Gilles Cohen-Tannoudji🇫🇷

    The cosmological constant, usually named Lambda, was introduced by Einstein in 1917 and abandoned by him as his biggest "blunder". It currently seems to make a spectacular comeback in the framework of the new cosmological standard model. One will explain why, together with the Planck's constant, the Boltzmann's constant, the celerity of light and the Newton's constant, also considered by Einstein, the cosmological constant may play a foundational role in the conceptual framework, an in the metrological framework a role comparable with the one attributed to Avogadro constant

    ↳ physics.hist-phastro-ph.COhep-phMetrologia(2018)·4 citations
13. 13*

    Quark-Meson-Coupling (QMC) model for finite nuclei, nuclear matter and beyond

    P. A. M. Guichon🇫🇷 · J. R. Stone🇬🇧 · A. W. Thomas🇦🇺

    The Quark-Meson-Coupling model, which self-consistently relates the dynamics of the internal quark structure of a hadron to the relativistic mean fields arising in nuclear matter, provides a natural explanation to many open questions in low energy nuclear physics, including the origin of many-body nuclear forces and their saturation, the spin-orbit interaction and properties of hadronic matter at a wide range of densities up to those occurring in the cores of neutron stars. Here we focus on four aspects of the model (i) a full comprehensive survey of the theory, including the latest developments, (ii) extensive application of the model to ground state properties of finite nuclei and hypernuclei, with a discussion of similarities and differences between the QMC and Skyrme energy density functionals, (iii) equilibrium conditions and composition of hadronic matter in cold and warm neutron stars and their comparison with the outcome of relativistic mean-field theories and, (iv) tests of the fundamental idea that hadron structure changes in-medium.

    ↳ nucl-thhep-phPPNP(2018)·105 citations
14. 14*

    Implications of Neutron Star Properties for the Existence of Light Dark Matter

    T. F. Motta🇦🇺 · P. A. M. Guichon🇫🇷 · A. W. Thomas🇦🇺

    It was recently suggested that the discrepancy between two methods of measuring the lifetime of the neutron may be a result of an unseen decay mode into a dark matter particle which is almost degenerate with the neutron. We explore the consequences of this for the properties of neutron stars, finding that their known properties are in conflict with the existence of such a particle.

    ↳ nucl-thhep-phJ.Phys.G(2018)·78 citations
15. 15*

    Tibet${}^{\prime }$s Window on Primordial Gravitational Waves

    Hong Li🇨🇳 · Si-Yu Li🇨🇳 · Yang Liu🇨🇳 · Yong-Ping Li🇨🇳 · Xinmin Zhang🇨🇳

    As an essential part of China’s Gravitational Waves Program, the Ali CMB Polarization Telescope (AliCPT) is a ground-based experiment aiming at the Primordial Gravitational Waves (PGWs) by measuring B-mode polarization of Cosmic Microwave Background (CMB). First proposed in 2014 and currently in fast construction phase, AliCPT is China’s first CMB project that plans for commissioning in 2019. Led by the Institute of High Energy Physics (IHEP) under the Chinese Academy of Sciences (CAS), the project is a worldwide collaboration of more than fifteen universities and research institutes. Ali CMB Project is briefly introduced.

    ↳ astro-ph.IMastro-ph.COgr-qchep-ph+1Nature Astron.(2018)·27 citations
16. 16*

    Scale-dependent galaxy bias, CMB lensing-galaxy cross-correlation, and neutrino masses

    Elena Giusarma🇺🇸 · Sunny Vagnozzi🇸🇪 · Shirley Ho🇺🇸 · Simone Ferraro🇺🇸 · Katherine Freese🇸🇪 · Rocky Kamen-Rubio🇺🇸 · Kam-Biu Luk🇺🇸

    One of the most powerful cosmological datasets when it comes to constraining neutrino masses is represented by galaxy power spectrum measurements, $P_{gg}(k)$. The constraining power of $P_{gg}(k)$ is however severely limited by uncertainties in the modeling of the scale-dependent galaxy bias $b(k)$. In this Letter we present a new method to constrain $b(k)$ by using the cross-correlation between the Cosmic Microwave Background (CMB) lensing signal and galaxy maps ($C_{\ell }^{\kappa \mathrm{g}}$) using a simple but theoretically well-motivated parametrization for $b(k)$. We apply the method using $C_{\ell }^{\kappa \mathrm{g}}$ measured by cross-correlating Planck lensing maps and the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 11 (DR11) CMASS galaxy sample, and $P_{gg}(k)$ measured from the BOSS DR12 CMASS sample. We detect a non-zero scale-dependence at moderate significance, which suggests that a proper modeling of $b(k)$ is necessary in order to reduce the impact of non-linearities and minimize the corresponding systematics. The accomplished increase in constraining power of $P_{gg}(k)$ is demonstrated by determining a 95% C.L. upper bound on the sum of the three active neutrino masses $M_{\nu }$ of $M_{\nu }<0.19\mathrm{eV}$. This limit represents a significant improvement over previous bounds with comparable datasets. Our method will prove especially powerful and important as future large-scale structure surveys will overlap more significantly with the CMB lensing kernel providing a large cross-correlation signal.

    ↳ astro-ph.COastro-ph.GAastro-ph.HEgr-qc+1PRD(2018)·117 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.