Thu·Mar 9, 2017Thursday·March 9, 2017

1. 01*

   Leptogenesis after Inflation in a Pati-Salam Model

   Stuart Raby🇺🇸

   In this talk I discuss a supersymmetric Pati-Salam model of fermion masses and mixing angles which fits low energy data. The model is then extended to include an inflationary sector which is shown to be consistent with Bicep2-Keck-Planck data. The energy scale during inflation is associated with the PS symmetry breaking scale. Finally, the model is shown to be consistent with the observed baryon-to-entropy ratio necessary for Big Bang Nucleosynthesis. It turns out that only the heaviest right-handed neutrino decays produce the correct sign of the baryon-to-entropy ratio. Nevertheless, we obtain the observed value due to the process of instant preheating.

   hep-phAIP Conf.Proc.(2017)·0 citations
2. 02*

   A review of gravitational waves from cosmic domain walls

   Ken'ichi Saikawa🇩🇪

   In this contribution, we discuss the cosmological scenario where unstable domain walls are formed in the early universe and their late-time annihilation produces a significant amount of gravitational waves. After describing cosmological constraints on long-lived domain walls, we estimate the typical amplitude and frequency of gravitational waves observed today. We also review possible extensions of the standard model of particle physics that predict the formation of unstable domain walls and can be probed by observation of relic gravitational waves. It is shown that recent results of pulser timing arrays and direct detection experiments partially exclude the relevant parameter space, and that a much wider parameter space can be covered by the next generation of gravitational wave observatories.

   hep-phastro-ph.COgr-qcUniverse(2017)·256 citations
3. 03*

   Quantum diffusion of electromagnetic fields of ultrarelativistic spin-half particles

   Balthazar Peroutka🇺🇸 · Kirill Tuchin🇺🇸

   We compute electromagnetic fields created by a relativistic charged spin-half particle in empty space at distances comparable to the particle Compton wavelength. The particle is described as a wave packet evolving according to the Dirac equation. It produces the electromagnetic field that is essentially different from the Coulomb field due to the quantum diffusion effect.

   hep-phNPA(2017)·9 citations
4. 04*

   De la structure de jauge des équations de Maxwell à l'étude des théories au delà du Modèle Standard grâce à la mesure du couplage trilinéaire du champ de Higgs

   Valdo Tatitscheff🇫🇷

   The concept of gauge theories progressively emerged during the 20th century while the building of the Standard Model (SM) of particle physics. This work focusses on some aspects of gauge theories. First, a modern interpretation of Maxwell's equations in terms of differential forms motivates a geometric definition of gauge theories as a theory of connections on principle bundles. After presenting some historical facts about the notion of gauge in particle physics, the geometrical construction is used to study the electroweak theory and the SM. Though the SM has not been defaulted by any experiments yet, it still remains theoretically incomplete. The Higgs boson discovered in 2012 at LHC, is a particle about which we do not know lots yet. Some interesting clues about how one should extend the SM could be obtained through the observation of significant deviations between the measured value of some parameter of the Higgs boson, and the one predicted by the SM. The trilinear Higgs coupling is one of those interesting parameters. The last part of this work is a phenomenological study of the impact of variations of this coupling on the distributions one can typically get from the CMS particle detector, at LHC.

   hep-phmath-phmath.MP0 citations
5. 05*

   Recent status of the understanding of neutrino-nucleus cross section

   H. Haider🇮🇳 · M. Sajjad Athar🇮🇳 · S. K. Singh🇮🇳

   In this work we have presented current understanding of neutrino-nucleon/nucleus cross sections in the few GeV energy region relevant for a precise determination of neutrino oscillation parameters and CP violation in the leptonic sector. In this energy region various processes like quasielastic and inelastic production of single and multipion production, coherent pion production, kaon, eta, hyperon production, associated particle production as well as deep inelastic scattering processes contribute to the neutrino event rates.

   hep-phnucl-thSpringer Proc.Phys.(2018)·0 citations
6. 06*

   Searches for the Anomalous FCNC Top-Higgs Couplings with Polarized Electron Beam at the LHeC

   XiaoJuan Wang🇨🇳 · Hao Sun🇨🇳 · Xuan Luo🇨🇳

   In this paper, we study the single top and Higgs associated production ${\mathrm{e}}^{-}\mathrm{p}\to {\nu }_{\mathrm{e}}\bar{\mathrm{t}}\to {\nu }_{\mathrm{e}}\mathrm{h}\bar{\mathrm{q}}(\mathrm{h}\to \mathrm{b}\bar{\mathrm{b}})$ in the top-Higgs FCNC couplings at the LHeC with the electron beam energy of $E_e$ = 60 GeV and $E_e$ = 120 GeV, combination of a 7 TeV and 50 TeV proton beam. With the possibility of e-beam polarization ($p_e$ = 0, $\pm 0.6$), we distinct the Cut-based method and the Multivariate Analysis (MVA) based method, and compare with the current experimental and theoretical limits. It is shown that the branching ratio Br $(\mathrm{t}\to \mathrm{uh})$ can be probed to 0.113 (0.093) $\%$, 0.071 (0.057) $\%$, 0.030 (0.022) $\%$ and 0.024 (0.019) $\%$ with the Cut-based (MVA-based) analysis at ($E_p$, $E_e$) = (7 TeV, 60 GeV), ($E_p$, $E_e$) = (7 TeV, 120 GeV), ($E_p$, $E_e$) = (50 TeV, 60 GeV) and ($E_p$, $E_e$) = (50 TeV, 120 GeV) beam energy and 1$\sigma$ level. With the possibility of e-beam polarization, the expected limits can be probed down to 0.090 (0.073) $\%$, 0.056 (0.045) $\%$, 0.024 (0.018) $\%$ and 0.019 (0.015) $\%$, respectively.

   hep-phAdv.High Energy Phys.(2017)·17 citations
7. 07*

   Probing the diffractive production of Z boson pair at forward rapidities at the LHC

   Hao Sun🇨🇳

   In this paper, we present the results from phenomenological analysis of Z boson pair hard diffractive production at the LHC. The calculation is based on the Regge factorization approach. Diffractive parton density functions extracted by the H1 Collaboration at DESY-HERA are used. The multiple Pomeron exchange corrections are considered through the rapidity gap survival probability factor. We give numerical predictions for single diffractive as well as double Pomeron exchange cross sections and compare with the photon-induced and non-diffractive ones. The contributions from quark-anti-quark collision and gluon-gluon fusion are displayed. Various kinematical distributions are presented. We make predictions which could be compared to future measurements at the LHC where forward proton detectors are installed and detector acceptances are considered.

   hep-phPRD(2017)·3 citations
8. 08*

   Symmetry restoration due to preheating and lepton number asymmetry

   Daijiro Suematsu🇯🇵

   We study a possible symmetry restoration due to the radiative effect of particles which are explosively produced in preheating after inflation. As its application, we consider a scenario for leptogenesis based on the lepton number asymmetry generated in the right-handed neutrino sector through the inflaton decay. The scenario is examined in a one-loop radiative neutrino mass model extended with singlet scalars.

   hep-phPRD(2017)·3 citations
9. 09*

   Flavour anomalies on the eve of the Run-2 verdict

   Diego Guadagnoli🇫🇷

   The RK measurement by LHCb suggests non-standard lepton-universality violation (LUV) to occur in b to s l+ l- decays, with effects in muons rather than electrons. It is intriguing that a number of other measurements of b to s l+ l- transitions by LHCb and B-factories are consistent in magnitude and sign with the RK effect, and fit a coherent effective-theory picture. Further indications of non-standard LUV are provided by the long-standing discrepancies in b to c tau nu transitions via the ratios R(D) and R(D^*). We review in detail the experimental situation and its rich outlook, the theoretical efforts -- and their challenges -- towards convincing dynamics beyond the effective-theory level, and discuss the many directions of further investigation that propagate from the current situation.

   hep-phMod.Phys.Lett.A(2017)·17 citations
10. 10*

    Nuclear parton density functions from jet production in DIS at the EIC

    M. Klasen🇩🇪 · K. Kovarik🇩🇪 · J. Potthoff🇩🇪

    We investigate the potential of inclusive-jet production in deep-inelastic scattering (DIS) at a future Electron-Ion Collider (EIC) to improve our current knowledge of nuclear parton density functions (PDFs). We demonstrate that the kinematic reach is extended similarly to inclusive DIS, but that the uncertainty of the nuclear PDFs, in particular of the gluon density at low Bjorken-x, is considerably reduced, by up to an order of magnitude compared to the present situation. Using an approximate next-to-next-to-leading order (aNNLO) calculation implemented in the program JetViP, we also make predictions for three different EIC designs and for four different light and heavy nuclei.

    hep-phhep-exnucl-exnucl-thPRD(2017)·36 citations
11. 11*

    General No-Scale Supergravity: An $\mathcal{F}$-$SU(5)$ Tale

    Dingli Hu🇺🇸 · Tianjun Li🇨🇳 · Adam Lux🇺🇸 · James A. Maxin🇺🇸 · Dimitri V. Nanopoulos🇺🇸

    We study the grand unification model flipped $SU(5)$ with additional vector-like particle multiplets, or $\mathcal{F}$-$SU(5)$ for short, in the framework of General No-Scale Supergravity. In our analysis we allow the supersymmetry (SUSY) breaking soft terms to be generically non-zero, thereby extending the phenomenologically viable parameter space beyond the highly constrained one-parameter version of $\mathcal{F}$-$SU(5)$. In this initial inquiry, the mSUGRA/CMSSM SUSY breaking terms are implemented. We find this easing away from the vanishing SUSY breaking terms enables a more broad mass range of vector-like particles, dubbed flippons, including flippons less than 1 TeV that could presently be observed at the LHC2, as well as a lighter gluino mass and SUSY spectrum overall. This presents heightened odds that the General No-Scale $\mathcal{F}$-$SU(5)$ viable parameter space can be probed at the LHC2. The phenomenology comprises both bino and higgsino dark matter, including a Higgs funnel region. Particle states emerging from the SUSY cascade decays are presented to experimentally distinguish amongst the diverse phenomenological regions.

    hep-phPLB(2017)·1 citation
12. 12*

    Holography at QCD-$T_{\mathrm{c}}$

    Rico Zöllner🇩🇪 · Burkhard Kampfer🇩🇪

    Within an extended soft wall model, we study the temperature dependence of the lowest vector meson states. Scales are adjusted by using as input the $\rho$ meson mass in vacuum and the velocity of sound from lattice QCD which displays a minimum at $T_{\mathrm{c}}$. The melting of the $\rho$ meson occurs at temperatures $\mathcal{O}(T_{\mathrm{c}})$.

    hep-phhep-thJ.Phys.Conf.Ser.(2017)·5 citations
13. 13*

    Gauge coupling unification without leptoquarks

    Georgios K. Karananas🇨🇭 · Mikhail Shaposhnikov🇨🇭

    We propose an interpretation of the gauge coupling unification scale which is not related to any new particle threshold. We revisit Grand Unified Theories and show that it is possible to completely eliminate the scalar as well as vector leptoquarks from the particle physics spectrum. As a consequence, in our approach the gauge hierarchy problem is put on different grounds, and the proton may be absolutely stable. In order to achieve that, we employ a number of nonlinear gauge-invariant constraints which only affect the superheavy degrees of freedom. We illustrate our considerations in a model based on the SU(5) group, with the generalization to other groups being straightforward. We discuss how scale or conformal invariance may be added to our proposal.

    hep-phhep-thPLB(2017)·21 citations
14. 14*

    A Reappraisal on Dark Matter Co-annihilating with a Top/Bottom Partner

    Wai-Yee Keung🇺🇸 · Ian Low🇺🇸 · Yue Zhang🇺🇸

    We revisit the calculation of relic density of dark matter particles co-annihilating with a top or bottom partner, by properly including the QCD bound-states (onia) effects of the colored partners, as well as the relevant electroweak processes which become important in the low mass region. We carefully set up the complete framework that incorporates the relevant contributions and investigate their effects on the cosmologically preferred mass spectrum, which turn out to be comparable in size to those coming from the Sommerfeld enhancement. We apply the calculation to three scenarios: bino-stop and bino-sbottom co-annihilations in supersymmetry, and a vector dark matter co-annihilating with a fermionic top partner. In addition, we confront our analysis of the relic abundance with recent direct detection experiments and collider searches at the LHC, which have important implications in the bino-stop and bino-sbottom scenarios. In particular, in the bino-stop case recent LHC limits have excluded regions of parameter with a direct detection rate that is above the neutrino floor.

    hep-phastro-ph.COhep-exPRD(2017)·28 citations
15. 15*

    Completing the hadronic Higgs boson decay at order ${\alpha }_s^4$

    Joshua Davies🇩🇪 · Matthias Steinhauser🇩🇪 · David Wellmann🇩🇪

    We compute four-loop corrections to the hadronic decay of the Standard Model Higgs boson which are induced by effective couplings to bottom quarks and gluons, mediated by the top quark. Our numerical results are comparable in size to the purely massless contributions which have been known for a few years. The results presented in this paper complete the order ${\alpha }_s^4$ corrections to the hadronic Higgs boson decay.

    hep-phNPB(2017)·49 citations
16. 16*

    Compositeness of hadron resonances in finite volume

    Yujiro Tsuchida🇯🇵 · Tetsuo Hyodo🇯🇵

    We develop a theoretical framework to quantify the structure of unstable hadron resonances. With the help of the corresponding system in a finite volume, we define the compositeness of resonance states which can be interpreted as a probability. This framework is used to study the structure of the scalar mesons f_0(980) and a_0(980). In both mesons, the Kbar K component dominates about a half of the wave function. The method is also applied to the Lambda(1405) resonance. We argue that a single energy level in finite volume represents the two eigenstates in infinite volume. The KbarK N component of Lambda(1405), including contributions from both eigenstates, is found to be 58%, and the rest is composed of the pi Sigma and other channels.

    ↳ nucl-thhep-phPRC(2018)·9 citations
17. 17*

    Assess the neutrino mass with micro and macro calorimeter approach

    Andrea Giachero🇮🇹

    Thanks to oscillation experiments it is now an established fact that neutrinos are massive particles. Yet, the assessment of neutrinos absolute mass scale is still an outstanding challenge in particle physics and cosmology as oscillation experiments are sensitive only to the squared mass differences of the three neutrino mass eigenstates. The mass hierarchy is not the only missing piece in the puzzle. Theories of neutrino mass generation call into play Majorana neutrinos and there are experimental observations pointing toward the existence of sterile neutrinos in addition to the three weakly interacting ones. Three experimental approaches are currently pursued: an indirect neutrino mass determination via cosmological observables, the search for neutrinoless double $\beta$-decay, and a direct measurement based on the kinematics of single $\beta$ or electron capture decays. Bolometers and calorimeters are low temperature detectors used in many applications, such as astrophysics, fast spectroscopy and particle physics. In particular, sensitive calorimeters play an important role in the neutrino mass measurement and in the search for the neutrinoless double $\beta$-decay. There has been great technical progress on low temperature detectors since they were proposed for neutrino physics experiments in 1984. This general detector paradigm can be implemented in devices as small as a micrometer for sub eV radiation or as large as 1 kg for MeV scale particles. Today this technique offers the high energy resolution and scalability required for leading edges and competitive experiments addressing the still open questions in neutrino physics.

    ↳ physics.ins-dethep-phJ.Phys.Conf.Ser.(2017)·3 citations
18. 18*

    Spectral functions for $\bar{D}$ meson and ${\bar{D}}_0^{\ast }$ meson in nuclear matter with partial restoration of chiral symmetry

    Daiki Suenaga🇯🇵 · Shigehiro Yasui🇯🇵 · Masayasu Harada🇯🇵

    We investigate the in-medium masses of a $\bar{D}(0^{-})$ meson and a ${\bar{D}}_0^{\ast }(0^{+})$ meson and spectral functions for $\bar{D}$ and ${\bar{D}}_0^{\ast }$ meson channels in nuclear matter. These mesons are introduced as chiral partner in the chiral symmetry broken vacuum, hence they are useful to explore the partial restoration of the broken chiral symmetry in nuclear matter. We consider the linear sigma model to describe the chiral symmetry breaking. Our study shows that the loop corrections to $\bar{D}$ and ${\bar{D}}_0^{\ast }$ meson masses provide a smaller mass splitting at finite density than that in vacuum, whose result indicates a tendency of the restoration of the chiral symmetry. We investigate also the spectral function for ${\bar{D}}_0^{\ast }$ meson channel, and find three peaks. The first peak which corresponds to the resonance of ${\bar{D}}_0^{\ast }$ meson is broadened by collisions with nucleons in medium, and the peak position shifts to lower mass due to the partial restoration of chiral symmetry as the density increases. The second peak is identified as a threshold enhancement which shows a remarkable enhancement as the density increase. The third peak is Landau damping. The obtained properties of $\bar{D}$ and ${\bar{D}}_0^{\ast }$ mesons in nuclear matter will provide useful information for experiments.

    ↳ nucl-thhep-phPRC(2017)·21 citations
19. 19*

    Gravitational waves generated from the cosmological QCD phase transition within AdS/QCD

    M. Ahmadvand🇮🇷 · K. Bitaghsir Fadafan🇮🇷

    We study the gravitational waves produced by the collision of the bubbles as a probe for the cosmological first order QCD phase transition, considering heavy static quarks. Using AdS/QCD and the correspondence between a first order Hawking-Page phase transition and confinement-deconfinement phase transition, we find the spectrum and the strain amplitude of the gravitational wave within the hard and soft wall models. We postulate the duration of the phase transition corresponds to the evaporation time of the black hole in the five dimensional dual gravity space, and thereby obtain a bound on the string length in the space and correspondingly on the duration of the QCD phase transition. We also show that IPTA and SKA detectors will be able to detect these gravitational waves, which can be an evidence for the first order deconfinement transition.

    ↳ hep-thgr-qchep-phPLB(2017)·35 citations
20. 20*

    Onset of $\eta$-nuclear binding in a pionless EFT approach

    N. Barnea🇮🇱 · B. Bazak🇫🇷 · E. Friedman🇮🇱 · A. Gal🇮🇱

    $\eta NNN$ and $\eta NNNN$ bound states are explored in stochastic variational method (SVM) calculations within a pionless effective field theory (EFT) approach at leading order. The theoretical input consists of regulated $NN$ and $NNN$ contact terms, and a regulated energy dependent $\eta N$ contact term derived from coupled-channel models of the $N^{\ast }(1535)$ nucleon resonance plus a regulated $\eta NN$ contact term. A self consistency procedure is applied to deal with the energy dependence of the $\eta N$ subthreshold input, resulting in a weak dependence of the calculated $\eta$-nuclear binding energies on the EFT regulator. It is found, in terms of the $\eta N$ scattering length $a_{\eta N}$, that the onset of binding $\eta {}^3$He requires a minimal value of Re$a_{\eta N}$ close to 1 fm, yielding then a few MeV $\eta$ binding in $\eta {}^4$He. The onset of binding $\eta {}^4$He requires a lower value of Re$a_{\eta N}$, but exceeding 0.7 fm.

    ↳ nucl-thhep-phnucl-exPLB(2017)·37 citations
21. 21*

    Phase Transitions, Inhomogeneous Horizons and Second-Order Hydrodynamics

    Maximilian Attems🇪🇸 · Yago Bea🇪🇸 · Jorge Casalderrey-Solana🇬🇧 · David Mateos🇪🇸 · Miquel Triana🇪🇸 · Miguel Zilhao🇪🇸

    We use holography to study the spinodal instability of a four-dimensional, strongly-coupled gauge theory with a first-order thermal phase transition. We place the theory on a cylinder in a set of homogeneous, unstable initial states. The dual gravity configurations are black branes afflicted by a Gregory-Laflamme instability. We numerically evolve Einstein's equations to follow the instability until the system settles down to a stationary, inhomogeneous black brane. The dual gauge theory states have constant temperature but non-constant energy density. We show that the time evolution of the instability and the final states are accurately described by second-order hydrodynamics. In the static limit, the latter reduces to a single, second-order, non-linear differential equation from which the inhomogeneous final states can be derived.

    ↳ hep-thgr-qchep-phnucl-thJHEP(2017)·53 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.