Mon·Sep 11, 2017Monday·September 11, 2017

1. 01*

   Effective potential at three loops

   Stephen P. Martin🇺🇸

   I present the effective potential at three-loop order for a general renormalizable theory, using the \MSbar renormalization scheme and Landau gauge fixing. As applications and illustrative points of reference, the results are specialized to the supersymmetric Wess-Zumino model and to the Standard Model. In each case, renormalization group scale invariance provides a consistency check. In the Wess-Zumino model, the required vanishing of the minimum vacuum energy yields an additional check. For the Standard Model, I carry out the resummation of Goldstone boson contributions, which provides yet more opportunities for non-trivial checks, and obtain the minimization condition for the Higgs vacuum expectation value at full three-loop order. An infrared divergence due to doubled photon propagators appears in the three-loop Standard Model effective potential, but it does not affect the minimization condition or physical observables and can be eliminated by resummation.

   hep-phPRD(2017)·52 citations
2. 02*

   Muon Pair Production in Radiative Decays of Heavy Quarkonia

   A. V. Luchinsky🇷🇺

   Muon pair production in exclusive radiative decays ${\chi }_{cJ}\to J/\psi \mu \mu$, ${\chi }_{bJ}\to {\rm Y}\mu \mu$ are considered. We present numerical values of the branching fractions and distributions over various kinematical variables.

   hep-phMod.Phys.Lett.A(2017)·14 citations
3. 03*

   Weak-decay searches for $Qs\bar{u}\bar{d}$ tetraquarks

   Fu-Sheng Yu🇨🇳

   We propose to search for the open heavy-flavor exotic states with the quark components of $Qs\bar{u}\bar{d}$ with $Q=b,c$ via their weak decays. If there exist such exotic states below the $BK$ or $DK$ thresholds, they can only decay weakly. The advantages include: (i) the experimental backgrounds from the secondary decay vertex are much lower due to the long lifetimes, (ii) the productions are large enough for only one heavy quark in such states, (iii) the thresholds of $BK$ or $DK$ are about 260 MeV higher compared to the $B_s\pi$ or $D_s\pi$ thresholds of the configurations of $Qu\bar{s}\bar{d}$ or $Qd\bar{s}\bar{u}$ , with a higher possibility to exist such weakly-decay particles, and (iv) if observed, their inner structures are easier understood since they can not be induced by the kinematic effects.

   hep-phhep-exEPJC(2022)·19 citations
4. 04*

   The Loop-Tree Duality: Progress Report

   G. Chachamis🇪🇸 · G. Rodrigo🇪🇸

   We review the recent developments of the Loop-Tree Duality method, focussing our discussion on the first numerical implementation and its use in the direct numerical computation of multi-leg Feynman integrals. Non-trivial examples are presented.

   hep-phhep-thPoS(2018)·2 citations
5. 05*

   Prompt photon production with POWHEG

   M. Klasen🇩🇪

   We present a calculation of prompt photon and associated photon-jet production at next-to-leading order that is consistently matched to parton showers with POWHEG. Specific issues that appear in photon radiation are discussed. Numerical results are compared to pp collision data at RHIC energies and shown to describe the data better than inclusive next-to-leading order calculations or those with leading order Monte Carlo generators like PYTHIA alone.

   hep-phCERN Proc.(2018)·0 citations
6. 06*

   Azimuthal-angle Observables in Inclusive Three-jet Production

   G. Chachamis🇪🇸 · F. Caporale🇪🇸 · F. G. Celiberto🇮🇹 · D. Gordo Gomez🇪🇸 · A. Sabio Vera🇪🇸

   We discuss the impact of corrections beyond the leading-logarithmic accuracy on some recently proposed LHC observables that are based on azimuthal-angle ratios in a kinematical setup that is an extension to the usual one for Mueller-Navelet jets, after requiring an extra tagged jet in central regions of rapidity. The corrections tend to be mild which suggests that these observables are an excellent way to probe the onset of BFKL effects at hadronic colliders.

   hep-phPoS(2018)·20 citations
7. 07*

   GUT and flavor models for neutrino masses and mixing

   Davide Meloni🇮🇹

   In the recent years neutrino experiments have studied in detail the phenomenon of neutrino oscillations and most of the oscillation parameters have been measured with a good accuracy. However, in spite of many interesting ideas, the problem of flavor in the lepton sector remains an open issue. In this review, we discuss the state of the art of models for neutrino masses and mixings formulated in the context of flavor symmetries, with particular emphasis on the role played by grand unified gauge groups.

   hep-phFront.in Phys.(2017)·22 citations
8. 08*

   QCD resummation effects in forward $J/\psi$ and very backward jet inclusive production at the LHC

   R. Boussarie🇵🇱 · B. Ducloué🇫🇮 · L. Szymanowski🇵🇱 · S. Wallon🇫🇷

   We propose and study the inclusive production of a forward $J/\psi$ and a very backward jet at the LHC as an observable to reveal high-energy resummation effects à la BFKL. Our different predictions are based on the various existing mechanisms to describe the production of the $J/\psi$, namely, NRQCD singlet and octet contributions, and the color evaporation model.

   hep-phhep-exPoS(2018)·8 citations
9. 09*

   Precision predictions for associated gluino-gaugino production at the LHC

   B. Fuks🇫🇷 · M. Klasen🇩🇪 · M. Sunder🇩🇪

   Now that the mass limits for gluinos have been pushed to the few-TeV range, they might only be visible at the LHC in associated production with lighter gauginos. We compute the corresponding cross section at next-to-leading logarithmic (NLL) and next-to-leading order (NLO) precision in the QCD coupling constant. The resulting expressions are implemented in the public code RESUMMINO and can be directly used in the corresponding experimental searches.

   hep-phPoS(2017)·2 citations
10. 10*

    Direct detection of neutralino dark matter with DM@NLO

    M. Klasen🇩🇪 · K. Kovarik🇩🇪 · S. Schmiemann🇩🇪

    We calculate spin-independent and spin-dependent direct detection cross sections of neutralino dark matter at next-to-leading order of QCD. The numerical effects are comparable in size to the uncertainties in the nuclear matrix elements. Our results are applicable to bino, wino or higgsino dark matter and allow for consistent correlations with the relic density in DM@NLO.

    hep-phPoS(2017)·3 citations
11. 11*

    Status and discovery prospects for light pseudoscalars in the NMSSM

    Robin Aggleton🇬🇧 · Daniele Barducci🇮🇹 · Nils-Erik Bomark🇳🇴 · Stefano Moretti🇬🇧 · Claire Shepherd-Themistocleous🇬🇧

    While most BSM searches at the LHC focus on heavy new states, the NMSSM contains the possibility of new light states that have escaped detection due to their singlet nature. Here we focus on light pseudoscalars, investigating the parameter space impact of recent LHC searches for such light states stemming from the decay of the 125 GeV Higgs boson. It is shown that, though direct searches can not yet compete with the requirement of the 125 GeV scalar having SM-like couplings, the searches are touching the allowed parameter space and should make a phenomenological impact in the near future.

    hep-phPoS(2017)·0 citations
12. 12*

    Anisotropy in the equation of state of strongly magnetized quark matter within the Nambu--Jona-Lasinio Model

    Sidney S. Avancini🇧🇷 · Veronica Dexheimer🇺🇸 · Ricardo L. S. Farias🇧🇷 · Varese S. Timóteo🇧🇷

    In this article, we calculate the magnetization and other thermodynamical quantities for strongly magnetized quark matter within the Nambu-Jona-Lasinio model at zero temperature. We assume two scenarios, chemically equilibrated charge neutral matter present in the interior of compact stars and zero-strangeness isospin-symmetric matter created in nuclear experiments. We show that the magnetization oscillates with density but in a much more smooth form than what was previously shown in the literature. As a consequence, we do not see the unphysical behavior in the pressure in the direction perpendicular to the magnetic field that was previously found. Finally, we also analyze the effects of a vector interaction on our results.

    hep-phastro-ph.HEnucl-thPRC(2018)·31 citations
13. 13*

    Charged Higgs production with a $W$ boson or a top quark

    Nikolaos Kidonakis🇺🇸

    I present theoretical results for charged Higgs production in association with a $W$ boson or a top quark at the LHC. I calculate higher-order threshold corrections and show that they are very significant. I present detailed results for total cross sections as well as transverse-momentum and rapidity distributions for various LHC energies.

    hep-phPoS (EPS-HEP2017) 296·1 citation
14. 14*

    Solar neutrinos at keV energies: thermal flux

    Edoardo Vitagliano🇩🇪 · Javier Redondo🇪🇸 · Georg Raffelt🇩🇪

    The neutrino flux at Earth is dominated in the keV energy range by the neutrinos produced in the Sun through thermal processes, namely photo production, bremsstrahlung, plasmon decay, and emission in free-bound and bound-bound transitions of partially ionized elements heavier than hydrogen and helium. Such a component of the neutrino flux is conspicuously absent from popular analyses of the all-sources spectrum at Earth, whereas if detected it could be a source of information about solar physics. Moreover, it would be the relevant background for keV-mass sterile neutrino dark matter direct searches.

    hep-phastro-ph.SRJ.Phys.Conf.Ser.(2020)·5 citations
15. 15*

    Probing new spin-independent interactions through precision spectroscopy in atoms with few electrons

    Cédric Delaunay🇫🇷 · Claudia Frugiuele🇮🇱 · Elina Fuchs🇮🇱 · Yotam Soreq🇺🇸

    The very high precision of current measurements and theory predictions of spectral lines in few-electron atoms allows to efficiently probe the existence of exotic forces between electrons, neutrons and protons. We investigate the sensitivity to new spin-independent interactions in transition frequencies (and their isotopic shifts) of hydrogen, helium and some helium-like ions. We find that present data probe new regions of the force-carrier couplings to electrons and neutrons around the MeV mass range. We also find that, below few keV, the sensitivity to the electron coupling in precision spectroscopy of helium and positronium is comparable to that of the anomalous magnetic moment of the electron. Finally, we interpret our results in the dark-photon model where a new gauge boson is kinetically mixed with the photon. There, we show that helium transitions, combined with the anomalous magnetic moment of the electron, provide the strongest indirect bound from laboratory experiments above 100keV.

    hep-phphysics.atom-phquant-phPRD(2017)·80 citations
16. 16*

    An explanation for dark matter and dark energy consistent with the Standard Model of particle physics and General Relativity

    A. Deur🇺🇸

    Analyses of internal galaxy and cluster dynamics typically employ Newton's law of gravity, which neglects the field self-interaction effects of General Relativity. This may be why dark matter seems necessary. The Universe evolution, on the other hand, is treated with the full theory, General Relativity. However, the approximations of isotropy and homogeneity, normally used to derive and solve the Universe evolution equations, effectively suppress General Relativity's field self-interaction effects and this may introduce the need for dark energy. Calculations have shown that field self-interaction increases the binding of matter inside massive systems, which may account for galaxy and cluster dynamics without invoking dark matter. In turn, energy conservation dictates that the increased binding must be balanced by an effectively decreased gravitational interaction outside the massive system. In this article, such suppression is estimated and its consequence for the Universe's evolution is discussed. Observations are reproduced without need for dark energy.

    ↳ astro-ph.COhep-phEPJC(2019)·22 citations
17. 17*

    Role of net baryon density on rapidity width of identified particles from the lowest energies available at the CERN Super Proton Synchrotron to those at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

    Nur Hussain🇮🇳 · Buddhadeb Bhattacharjee🇮🇳

    Widths of the rapidity distributions of various identified hadrons generated with the UrQMD-3.4 event generator at all the Super Proton Synchrotron (SPS) energies have been presented and compared with the existing experimental results. An increase in the width of the rapidity distribution of $\Lambda$ could be seen with both Monte Carlo (MC) and experimental data for the studied energies. Using MC data, the study has been extended to Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies. A similar jump, as observed in the plot of rapidity width versus rest mass at Alternating Gradient Synchrotron (AGS) and all SPS energies, persists even at RHIC and LHC energies, confirming its universal nature from AGS to the highest LHC energies. Such observation indicates that pair production may not be the only mechanism of particle production at the highest LHC energies. However, with MC data, the separate mass scaling for mesons and baryons is found to exist even at the top LHC energy.

    ↳ nucl-thhep-phPRC(2017)·6 citations
18. 18*

    Setting Initial Conditions for Inflation with Reaction-Diffusion Equation

    Partha Bagchi🇮🇳 · Arpan Das🇮🇳 · Shreyansh S. Dave🇮🇳 · Srikumar Sengupta🇮🇳 · Ajit M. Srivastava🇮🇳

    We discuss the issue of setting appropriate initial conditions for inflation. Specifically, we consider natural inflation model and discuss the fine tuning required for setting almost homogeneous initial conditions over a region of order several times the Hubble size which is orders of magnitude larger than any relevant correlation length for field fluctuations. We then propose to use the special propagating front solutions of reaction-diffusion equations for localized field domains of smaller sizes. Due to very small velocities of these propagating fronts we find that the inflaton field in such a $fielddomain$ changes very slowly, contrary to naive expectation of rapid roll down to the true vacuum. Continued expansion leads to the energy density in the Hubble region being dominated by the vacuum energy, thereby beginning the inflationary phase. Our results show that inflation can occur even with a single localized field domain of size smaller than the Hubble size. We discuss possible extensions of our results for different inflationary models, as well as various limitations of our analysis (e.g. neglecting self gravity of the localized field domain).

    ↳ hep-thastro-ph.COgr-qchep-phGen.Rel.Grav.(2018)·2 citations
19. 19*

    Teaching particle physics to high school teachers

    Nils-Erik Bomark🇳🇴

    In Norway, particle physics is part of the high school curriculum in physics which introduces the need for good university teaching in particle physics without the usual technical approach. Given how much conflicting information and inaccurate explanations there are on the subject; how should we teach this to people without much knowledge in mathematics? By carefully explaining the fundamental consepts of the theory it is fully possible to achieve an appreciation of particle physics without much mathematics. Through the use of analogies, such as an analogy between the freedom in choosing timezone and the freedom in choosing phase angle, one can introduce gauge theory and hence show the underlying structure of the standard model.

    ↳ physics.ed-phhep-exhep-phphysics.pop-phPoS(2017)·0 citations
20. 20*

    Strangeness Production and Color Deconfinement

    Paolo Castorina · Salvatore Plumari · Helmut Satz

    The relative multiplicities for hadron production in different high energy collisions are in general well described by an ideal gas of all hadronic resonances, except that under certain conditions, strange particle rates are systematically reduced. We show that the suppression factor gamma_s, accounting for reduced strange particle rates in pp, pA and AA collisions at different collision energies, becomes a universal function when expressed in terms of the initial entropy density s_0 or the initial temperature T of the produced thermal medium. It is found that gamma_s increases from about 0.5 to 1.0 in a narrow temperature range around the quark-hadron transition temperature T_c = 160 MeV. Strangeness suppression thus disappears with the onset of color deconfinement; subsequently, full equilibrium resonance gas behavior is attained.

    ↳ nucl-thhep-ph
21. 21*

    Lorentzian Goldstone modes shared among photons and gravitons

    J.L. Chkareuli🇬🇪 · J. Jejelava🇬🇪 · Z. Kepuladze🇬🇪

    It has long been known that photons and gravitons may appear as vector and tensor Goldstone modes caused \ by spontaneous Lorentz invariance violation (SLIV). Usually this approach is considered for photons and gravitons separately. We develop the emergent electrogravity theory consisting of the ordinary QED and the tensor field gravity model which mimics the linearized general relativity in Minkowski spacetime. In this theory, Lorentz symmetry appears incorporated into higher global symmetries of the length-fixing constraints put on the vector and tensor fields involved, $A_{\mu }^2=\pm M_A^2$ and $H_{\mu \nu }^2=\pm M_H^2$ ($M_A$ and $M_H$ are the proposed symmetry breaking scales). We show that such a SLIV pattern being related to breaking of global symmetries underlying these constraints induces the massless Goldstone and pseudo-Goldstone modes shared among photon and graviton. While for a vector field case the symmetry of the constraint coincides with Lorentz symmetry $SO(1,3)$ of the electrogravity Lagrangian, the tensor field constraint itself possesses much higher global symmetry $SO(7,3)$, whose spontaneous violation provides a sufficient number of zero modes collected in a graviton. Accordingly, while photon may only contain true Goldstone modes, graviton appears at least partially composed from pseudo-Goldstone modes rather than from pure Goldstone ones. When expressed in terms of these modes, the theory looks essentially nonlinear and contains a variety of Lorentz and $CPT$ violating couplings. However, all SLIV effects turn out to be strictly cancelled in the lowest order processes that is considered in some detail. How this emergent electrogravity theory could be observationally differed from conventional QED and GR theories is also briefly discussed.

    ↳ hep-thgr-qchep-phEPJC(2018)·4 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.