Wed·Feb 6, 2019Wednesday·February 6, 2019

1. 01*

   Linking Scalar Dark Matter and Neutrino Masses with IceCube 170922A

   J.B.G. Alvey🇬🇧 · M. Fairbairn🇬🇧

   Two of the key unresolved issues facing Standard Model physics are (i) the appearance of a small but non-zero neutrino mass, and, (ii) the missing mass problem in the Universe. The focus of this paper is a previously proposed low energy effective theory that couples a dark scalar to Standard Model neutrinos. This provides a stable dark matter candidate as well as radiatively generating a neutrino mass. Within this framework we will then construct an entirely new bound from the IceCube-170922A event which takes into account (i) the possible neutrino mass hierarchies, (ii) the effect of cosmological redshift on e.g. the number density of cosmic neutrino background neutrinos, and, (iii) the non-degeneracy of neutrino mass and flavour eigenstates. This builds on work by Kelly and Machado (2018), where the authors placed new constraints on neutrinophilic and axion dark matter models. At low mediator masses, we find an improvement of an order of magnitude on current constraints from kaon decays. The constraint is complimentary (and slightly weaker) than current constraints from Big Bang Nucleosynthesis and the Cosmic Microwave Background. We explore how future higher energy events could improve this bound.

   hep-phastro-ph.HEJCAP(2019)·34 citations
2. 02*

   Anapole Dark Matter via Vector Boson Fusion Processes at the LHC

   Andrés Flórez🇨🇴 · Alfredo Gurrola🇺🇸 · Will Johns🇺🇸 · Jessica Maruri🇺🇸 · Paul Sheldon🇺🇸 · Kuver Sinha🇺🇸 · Savanna Rae Starko🇺🇸

   Dark matter that is electrically neutral but couples to the electromagnetic current through higher-dimensional operators constitutes an interesting class of models. We investigate this class of models at the Large Hadron Collider, focusing on the anapole moment operator in an effective field theory (EFT) framework, and utilizing the vector boson fusion (VBF) topology. Assuming proton-proton collisions at $\sqrt{s}=13$ TeV, we present the VBF anapole dark matter (ADM) cross sections and kinematic distributions as functions of the free parameters of the EFT, the cutoff scale $\Lambda$ and the ADM mass $m_{\chi }$. We find that the distinctive VBF topology of two forward jets and large dijet pseudorapidity gap is effective at reducing SM backgrounds, leading to a $5\sigma$ discovery reach for all kinematically allowed ADM masses with $\Lambda \le 1.65$ (1.15) TeV, assuming an integrated luminosity of 3000 (100) fb${}^{-1}$.

   hep-phPRD(2019)·24 citations
3. 03*

   GUT inspired $SO(5)\times U(1)\times SU(3)$ gauge-Higgs unification

   Shuichiro Funatsu🇨🇳 · Hisaki Hatanaka🇯🇵 · Yutaka Hosotani🇯🇵 · Yuta Orikasa🇨🇿 · Naoki Yamatsu🇯🇵

   $SO(5)\times U(1)\times SU(3)$ gauge-Higgs unification model inspired by $SO(11)$ gauge-Higgs grand unification is constructed in the Randall-Sundrum warped space. The 4D Higgs boson is identified with the Aharonov-Bohm phase in the fifth dimension. Fermion multiplets are introduced in the bulk in the spinor, vector and singlet representations of $SO(5)$ such that they are implemented in the spinor and vector representations of $SO(11)$. The mass spectrum of quarks and leptons in three generations is reproduced except for the down quark mass. The small neutrino masses are explained by the gauge-Higgs seesaw mechanism which takes the same form as in the inverse seesaw mechanism in grand unified theories in four dimensions.

   hep-phPRD(2019)·38 citations
4. 04*

   Monte Carlo event generators for high energy particle physics event simulation

   Andy Buckley🇬🇧 · Frank Krauss🇬🇧 · Simon Plätzer🇦🇹 · Michael Seymour🇬🇧 · Simone Alioli🇮🇹 · Jeppe Andersen🇬🇧 · Johannes Bellm🇸🇪 · Jon Butterworth🇬🇧 · Mrinal Dasgupta🇬🇧 · Claude Duhr🇨🇭 · Stefano Frixione🇮🇹 · Stefan Gieseke🇩🇪 and 31 other authors

   Monte Carlo event generators (MCEGs) are the indispensable workhorses of particle physics, bridging the gap between theoretical ideas and first-principles calculations on the one hand, and the complex detector signatures and data of the experimental community on the other hand. All collider physics experiments are dependent on simulated events by MCEG codes such as Herwig, Pythia, Sherpa, POWHEG, and MG5_aMC@NLO to design and tune their detectors and analysis strategies. The development of MCEGs is overwhelmingly driven by a vibrant community of academics at European Universities, who also train the next generations of particle phenomenologists. The new challenges posed by possible future collider-based experiments and the fact that the first analyses at Run II of the LHC are now frequently limited by theory uncertainties urge the community to invest into further theoretical and technical improvements of these essential tools. In this short contribution to the European Strategy Update, we briefly review the state of the art, and the further developments that will be needed to meet the challenges of the next generation.

   hep-ph27 citations
5. 05*

   Practical scheme from QCD to phenomena via Dyson-Schwinger equations

   Can Tang🇨🇳 · Fei Gao🇪🇸 · Yu-xin Liu🇨🇳

   We deliver a new scheme to compute the quark propagator and the quark-gluon interaction vertex through the coupled Dyson-Schwinger equations (DSEs) of QCD. We take the three-gluon vertex into account in our calculations, and implement the gluon propagator and the running coupling function fitted by the solutions of their respective DSEs. We obtain the momentum and current mass dependence of the quark propagator and the quark-gluon vertex, and the chiral quark condensate which agrees with previous results excellently. We also compute the quark-photon vertex within this scheme and give the anomalous chromo- and electro-magnetic moment of quark. The obtained results also agree with previous ones very well. These applications manifest that the new scheme is realistic and then practical for explaining the QCD-related phenomena.

   hep-phPRD(2019)·32 citations
6. 06*

   New mixing schemes for (3+1) neutrinos

   S. Dev🇮🇳 · Desh Raj🇮🇳 · Radha Raman Gautam🇮🇳 · Lal Singh🇮🇳

   We propose new mixing schemes for (3+1) neutrinos which describe mixing among active-active and active-sterile neutrinos. The mixing matrix in these mixing schemes can be factored into a zeroth order flavor symmetric part and another part representing small perturbations needed for generating non-zero $U_{e3}$, nonmaximal ${\theta }_{23}$, CP violation and active-sterile mixing. We find interesting correlations amongst various neutrino mixing angles and, also, calculate the parameter space for various parameters.

   hep-phNPB(2019)·10 citations
7. 07*

   Full NLO corrections to 3-jet production and R32 at the LHC

   Max Reyer🇩🇪 · Marek Schönherr🇨🇭 · Steffen Schumann🇩🇪

   We present the evaluation of the complete set of NLO corrections to three-jet production at the LHC. To this end we consider all contributions of $\mathcal{O}({\alpha }_s^n{\alpha }^m)$ with $n+m=3$ and $n+m=4$. This includes in particular also subleading Born contributions of electroweak origin, as well as electroweak virtual and QED real-radiative corrections. As an application we present results for the three- over two-jet ratio $R_{32}$. While the impact of non-QCD corrections on the total cross section is rather small, they can exceed $-10\%$ for high jet transverse momenta. The $R_{32}$ observable turns out to be very stable against electroweak corrections, receiving absolute corrections below $5\%$ even in the high-$p_T$ region.

   hep-phhep-exEPJC(2019)·25 citations
8. 08*

   Matching high-energy electroweak fermion loops onto the Fermi theory without higher dimensional operators

   Roberto Pittau🇪🇸

   We derive the conditions for matching high-energy renormalizable Quantum Field Theories onto low-energy nonrenormalizable ones by means of the FDR approach described in Fortsch.Phys. 63 (2015) 132-141. Our procedure works order-by-order in the loop expansion and avoids the addition of higher dimensional interactions into the nonrenormalizable Lagrangian. To illustrate our strategy, we match the high-energy fermion-loop corrections computed in the complete electroweak theory onto the nonrenormalizable four-fermion Fermi model. As a result, the Fermi Lagrangian can be used without modifications to reproduce, at arbitrary loop orders and energies, the exact electroweak interactions between two massless fermion lines induced by one-fermion-loop resummed gauge boson propagators.

   hep-phhep-thNPB(2020)·3 citations
9. 09*

   B anomalies and dark matter: a complex connection

   D.G. Cerdeno🇬🇧 · A. Cheek🇬🇧 · P. Martin-Ramiro🇪🇸 · J.M. Moreno🇪🇸

   We study an extension of the Standard Model that addresses the hints of lepton flavour universality violation observed in $B\to K^{(\ast )}{l}^{+}{l}^{-}$ decays at LHCb, while providing a viable candidate for dark matter. The model incorporates two new scalar fields and a Majorana fermion that induce one-loop contributions to $B$ meson decays. We show that agreement with observational data requires the new couplings to be complex and that the Majorana fermion can reproduce the observed dark matter relic density. This combination of cosmological and flavour constraints sets an upper limit on the dark matter and mediator masses. We have studied LHC dijet and dilepton searches, finding that they rule out large regions of parameter space by setting lower bounds on the dark matter and mediator masses. In particular, dilepton bounds are much more constraining in a future high-luminosity phase. Finally, we have computed the scattering cross section of dark matter off nuclei and compared it to the sensitivity of current and future direct detection experiments, showing that parts of the parameter space could be accessible in the future to multi-ton experiments. Future collider and direct DM searches complement each other to probe large areas of the parameter space of this model.

   hep-phastro-ph.COEPJC(2019)·41 citations
10. 10*

    A note on QED gauge invariance of off-shell amplitudes

    A. van Hameren🇵🇱

    The consistent construction of scattering amplitudes for processes with off-shell initial partons and involving electro-weak interactions is addressed.

    hep-ph6 citations
11. 11*

    Excited states of $\varphi$ meson

    Cheng-qun Pang🇨🇳

    In this paper, the excited states of $\varphi$ meson, especially containing the newly observed $X(2000)$ with $I(J^P)=0(1^{-})$ by the BESIII Collaboration, is studied. In addition, $Y(2175)$ as a $\varphi$ {\color{black}{meson excited state}} is investigated. The mass spectrum and strong decay behaviors of $\varphi$ {\color{black}{meson excited states}} are analyzed, which indicates that $X(2000)$ and $Y(2175)$ are the candidates of $\varphi (3S)$ and $\varphi (2D)$ states with $I(J^P)=0(1^{-})$, respectively. In addition, {\color{black}{$\varphi (1D)$ and $\varphi (4S)$ are}} predicted to have the mass of 1.87 GeV and 2.5 GeV and width of 550 MeV and 230 MeV, respectively.

    hep-phhep-exPRD(2019)·51 citations
12. 12*

    Charge symmetry violation in the determination of strangeness form factors

    Ali Alkathiri🇦🇺 · Ross D. Young🇦🇺 · James M. Zanotti🇦🇺

    The strange quark contributions to the electromagnetic form factors of the proton are ideal quantities to study the role of hidden flavor in the properties of the proton. This has motivated intense experimental measurements of these form factors. A major remaining source of systematic uncertainty in these determinations is the assumption that charge symmetry violation (CSV) is negligible. We use recent theoretical determinations of the CSV form factors and reanalyse the available parity-violating electron scattering data, up to $Q^2$ $\sim$ 1 GeV${}^2$. Our analysis considers systematic expansions of the strangeness electric and magnetic form factors of the proton. The results provide an update to the determination of strangeness over a range of $Q^2$ where, under certain assumptions about the effective axial form factor, an emergence of non-zero strangeness is revealed in the vicinity of $Q^2$ $\sim$ 0.6 GeV${}^2$. Given the recent theoretical calculations, it is found that the current limits on CSV do not have a significant impact on the interpretation of the measurements and hence suggests an opportunity for a next generation of parity-violating measurements to more precisely map the distribution of strange quarks.

    ↳ nucl-thhep-phPRC(2020)·0 citations
13. 13*

    Resistive dissipative magnetohydrodynamics from the Boltzmann-Vlasov equation

    Gabriel S. Denicol🇧🇷 · Etele Molnár🇩🇪 · Harri Niemi🇩🇪 · Dirk H. Rischke🇩🇪

    We derive the equations of motion of relativistic, resistive, second-order dissipative magnetohydrodynamics from the Boltzmann-Vlasov equation using the method of moments. We thus extend our previous work [Phys. Rev. D 98, 076009 (2018)], where we only considered the non-resistive limit, to the case of finite electric conductivity. This requires keeping terms proportional to the electric field $E^{\mu }$ in the equations of motions and leads to new transport coefficients due to the coupling of the electric field to dissipative quantities. We also show that the Navier-Stokes limit of the charge-diffusion current corresponds to Ohm's law, while the coefficients of electrical conductivity and charge diffusion are related by a type of Wiedemann-Franz law.

    ↳ nucl-thhep-phphysics.flu-dynphysics.plasm-phPRD(2019)·92 citations
14. 14*

    Neutrinos and Particle Physics Models

    Pierre Ramond🇺🇸

    As in Greek mythology, the neutrino was born in the mind of Wolfgang Pauli to salvage a fundamental principle. Its existence met with universal skepticism by a scientific community used to infer particles from experiment. Its detection in 1956 brought particle physics acceptance; its chirality explained maximal parity violation in $\beta$ decay; its (apparent) masslessness led theorists to imagine new symmetries. Neutrinos are pioneers of mutli-messenger astronomy, from the Sun, from SNA1987, and now through IceCube's blazar. The discovery of neutrino masses opened a new era in particle physics aswell as unexplored windows on the universe. -Tiny neutrino masses suggest new physics at very short distances through the Seesaw. - Neutrinos and quarks, unified by gauge structure, display different mass and mixing patterns: small quark mixing angles and two large neutrino mixing angles. This difference in mass and mixings in the midst of gauge unification may be an important clue towards Yukawa unification. - Neutrino mixings provide a new source of CP-violation, and may solve the riddle of matter-antimatter asymmetry. We present a historical journey of these "enfants terribles" of particle physics and their importance in understanding our universe.

    ↳ physics.hist-phhep-ph6 citations
15. 15*

    The Discovery of the Atmospheric Neutrino Anomaly

    John M. LoSecco🇺🇸

    The discovery of the missing atmospheric muon neutrinos known as the atmospheric neutrino anomaly, is briefly described. Learned and Lipari gave a general review of atmospheric neutrinos at the conference, including the discovery of the anomaly by IMB-1 and subsequent work. Questions answered in this brief note include: the cautious wording, the statistical significance, the 1992 eronious exclusion plot, the Kamiokande confirmation and SuperK's failure to cite the original 1986 IMB-1 discovery.

    ↳ physics.hist-phhep-exhep-phhep-th3 citations
16. 16*

    Fundamental Physics and Cosmology in the Extremely Large Telescopes Era

    C. J. A. P. Martins🇵🇹

    The observational evidence for the recent acceleration of the universe demonstrates that canonical theories of cosmology and particle physics are incomplete (or possibly incorrect) and that new physics is out there, waiting to be discovered. A crucial task for the next generation of astrophysical facilities is to search for, identify and ultimately characterise this new physics. I outline the theoretical arguments pointing to this new physics, and then discuss some unique contributions of the ELTs towards this endeavour, including tests of the stability of nature's fundamental couplings, tests of the behaviour of gravity in the strong-field regime, and mapping the expansion history of the universe in the deep matter era, by both direct and indirect means. I also briefly highlight how the ELTs can optimally complement other planned ground and space facilities, and stress the requirements that these searches impose on the instruments currently being built or developed.

    ↳ astro-ph.COhep-phphysics.ins-det3 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.