Mon·Sep 25, 2017Monday·September 25, 2017

1. 01*

   On the observable spectrum of theories with a Brout-Englert-Higgs effect

   Axel Maas🇦🇹 · René Sondenheimer🇩🇪 · Pascal Törek🇦🇹

   The physical, observable spectrum in gauge theories is made up from gauge-invariant states. The Fröhlich-Morchio-Strocchi mechanism allows in the standard model to map these states to the gauge-dependent elementary $W$, $Z$ and Higgs states. This is no longer necessarily the case in theories with a more general gauge group and Higgs sector. We classify and predict the physical spectrum for a wide range of such theories, with special emphasis on GUT-like cases, and show that discrepancies between the spectrum of elementary fields and physical particles frequently arise.

   hep-phhep-lathep-thAnnals Phys.(2019)·53 citations
2. 02*

   Solving differential equations for Feynman integrals by expansions near singular points

   Roman N. Lee🇷🇺 · Alexander V. Smirnov🇷🇺 · Vladimir A. Smirnov🇷🇺

   We describe a strategy to solve differential equations for Feynman integrals by powers series expansions near singular points and to obtain high precision results for the corresponding master integrals. We consider Feynman integrals with two scales, i.e. nontrivially depending on one variable. The corresponding algorithm is oriented at situations where canonical form of the differential equations is impossible. We provide a computer implementation of our algorithm in a simple example of four-loop generalized sun-set integrals with three equal non-zero masses. Our code provides values of the master integrals at any given point on the real axis with a required accuracy and a given order of expansion in the regularization parameter $ϵ$.

   hep-phJHEP(2018)·119 citations
3. 03*

   Massless on-shell box integral with arbitrary powers of propagators

   O. V. Tarasov🇷🇺

   The massless one-loop box integral with arbitrary indices in arbitrary space-time dimension $d$ is shown to reduce to a sum over three generalised hypergeometric functions. This result follows from the solution to the third order differential equation of hypergeometric type. To derive the differential equation, the Gröbner basis technique for integrals with noninteger powers of propagators was used. A complete set of recurrence relations from the Gröbner basis is presented. The first several terms in the $\epsilon =(4-d)/2$ expansion of the result are given.

   hep-phJ.Phys.A(2018)·8 citations
4. 04*

   Gravitational Waves from Hidden QCD Phase Transition

   Mayumi Aoki🇯🇵 · Hiromitsu Goto🇯🇵 · Jisuke Kubo🇯🇵

   Drastic changes in the early universe such as first-order phase transition can produce a stochastic gravitational wave (GW) background. We investigate the testability of a scale invariant extension of the standard model (SM) using the GW background produced by the chiral phase transition in a strongly interacting QCD-like hidden sector, which, via a SM singlet real scalar mediator, triggers the electroweak phase transition. Using the Nambu--Jona-Lasinio method in a mean field approximation we estimate the GW signal and find that it can be tested by future space based detectors.

   hep-phPRD(2017)·70 citations
5. 05*

   Possible roles of Peccei-Quinn symmetry in an effective low energy model

   Daijiro Suematsu🇯🇵

   Strong $CP$ problem is known to be solved by imposing Peccei-Quinn (PQ) symmetry. However, domain wall problem caused by the spontaneous breaking of its remnant discrete subgroup could make models invalid in many cases. We propose a model in which the PQ charge is assigned quarks so as to escape this problem without introducing any extra colored fermions. In the low energy effective model resulting after the PQ symmetry breaking, both the quark mass hierarchy and the CKM mixing could be explained through Froggatt-Nielsen mechanism. If the model is combined with the lepton sector supplemented by an inert doublet scalar and right-handed neutrinos, the effective model reduces to the scotogenic neutrino mass model in which both the origin of neutrino masses and dark matter are closely related. The strong $CP$ problem could be related to the quark mass hierarchy, neutrino masses and dark matter through the PQ symmetry.

   hep-phPRD(2017)·6 citations
6. 06*

   Spontaneous mass generation suggests small dimension of the SM group U(1)xSU(2)xSU(3)

   Felipe J. Llanes-Estrada🇪🇸 · Guillermo Garcia Fernandez🇪🇸 · Jesus Guerrero Rojas🇪🇸

   The reasons behind the gauge symmetry of the Standard Model, U(1)xSU(2)xSU(3), are still unsettled. One obvious feature is the low dimensionality of all its subgroups. Under certain conditions, a negative answer to the question "why not larger groups like SU(15), or for that matter, SP(26) or E7?" is possible. We have recently observed that fermions charged under large groups acquire much bigger dynamical masses, all things being equal at a high e.g. GUT scale, than ordinary quarks. Should such multicharged fermions exist, they are just too heavy to be observed today (and have either decayed early on if coupled to the rest of the Standard Model, or become reliquial dark matter if uncoupled). Their mass scale is dictated by strong antiscreening of the running coupling for those larger groups (with an appropriately small number of flavors) together with scaling properties of the Dyson-Schwinger equation for the fermion mass. The generated fermion mass (assuming only few flavors, to avoid spoiling antiscreening) grows exponentially with the number of colors as M(N_c) ~ exp(N_c) for scales much below the GUT scale. Large groups would be strongly coupled already near the GUT scale and fermions charged thereunder have correspondingly large masses.

   hep-phPoS(2017)·1 citation
7. 07*

   Phenomenology of Majorons

   Julian Heeck🇧🇪

   Majorons are the Goldstone bosons associated to lepton number and thus closely connected to Majorana neutrino masses. Couplings to charged fermions arise at one-loop level, including lepton-flavor-violating ones that lead to decays $\ell \to {\ell }^{\prime }J$, whereas a coupling to photons is generated at two loops. The typically small couplings make massive majorons a prime candidate for long-lived dark matter. Its signature decay into two mono-energetic neutrinos is potentially detectable for majoron masses above MeV.

   hep-ph15 citations
8. 08*

   Calculation of the Decay Rate of Tachyonic Neutrinos against Charged-Lepton-Pair and Neutrino-Pair Cerenkov Radiation

   Ulrich D. Jentschura🇺🇸 · Istvan Nandori🇭🇺 · Robert Ehrlich🇺🇸

   We consider in detail the calculation of the decay rate of high-energy superluminal neutrinos against (charged) lepton pair Cerenkov radiation (LPCR), and neutrino pair Cerenkov radiation (NPCR), i.e., against the decay channels nu -> nu e+ e- and nu -> nu nubar nu. Under the hypothesis of a tachyonic nature of neutrinos, these decay channels put constraints on the lifetime of high-energy neutrinos for terrestrial experiments as well as on cosmic scales. For the oncoming neutrino, we use the Lorentz-covariant tachyonic relation E_nu = (p^2 - m_nu^2)^(1/2), where m_nu is the tachyonic mass parameter. We derive both threshold conditions as well as decay and energy loss rates, using the plane-wave fundamental bispinor solutions of the tachyonic Dirac equation. Various intricacies of rest frame versus lab frame calculations are highlighted. The results are compared to the observations of high-energy IceCube neutrinos of cosmological origin.

   hep-phJ.Phys.G(2017)·10 citations
9. 09*

   The five-loop Beta function for a general gauge group and anomalous dimensions beyond Feynman gauge

   Thomas Luthe🇩🇪 · Andreas Maier🇬🇧 · Peter Marquard🇩🇪 · York Schroder🇨🇱

   We focus on a non-abelian gauge field coupled to a single (but general) representation of a family of Nf fermions. By using the same machinery that had allowed us to evaluate the sub-leading large-Nf term of the five-loop Beta function earlier, we here report on a confirmation of the all-Nf result that has in the meantime been published by another group. Furthermore, in order to push forward the 5-loop renormalization program regarding gauge parameter dependence, we present the linear terms of the complete set of anomalous dimensions, in an expansion in the covariant gauge parameter around the Feynman gauge.

   hep-phhep-thJHEP(2017)·244 citations
10. 10*

    Some Phenomenologies of a Simple Scotogenic Inverse Seesaw Model

    Yi-Lei Tang🇰🇷

    In this paper, we discuss and calculate the electroweak parameters $R_l$, $A_l$, and $N_{\nu }^l$ in a model that combine inverse seesaw with the scotogenic model. Dark matter relic density is also considered. Due to the stringent constraint from the ATLAS experimental data, it is difficult to detect the loop effect on $R_l$, $A_l$ in this model considering both the theoretical and future experimental uncertainties. However, $N_{\nu }^l$ can sometimes become large enough for the future experiments to verify.

    hep-phPRD(2018)·7 citations
11. 11*

    Photon-jet correlations at RHIC and the LHC

    M. Klasen🇩🇪

    We present POWHEG predictions for photon-jet correlations at RHIC and the LHC. We show that the total transverse-momentum spectrum of photons and jets is modified not only by medium, but also by higher-order QCD effects, as is the distribution in their relative azimuthal angle. At the LHC, photon-jet measurements in the forward region allow to probe parton momentum fractions of lead ions down to 10${}^{-4}$.

    hep-ph0 citations
12. 12*

    Two-Loop Renormalization Group Equations and Gauge Couplings Unification

    Antonio Costantini🇮🇹

    We analize the impact of two-loop renormalization group equations on the $SU(3{)}_c\times SU(2{)}_w\times U(1{)}_Y$ gauge couplings unification in various supersymmetric theories. In general the presence of superfields in higher representation than the doublet spoil the gauge couplings unification at one-loop. The situation is more interesting when the renormalization group equations are calculated at two-loop. In this case we show that the unification of the gauge couplings can be achieved for models with triplet superfield(s). In the analysis of the models with triplet superfield(s) we show that the dimensionless couplings do not have a Landau pole in their evolution at high energies but they run to a nontrivial ultraviolet fixed point.

    hep-phhep-th0 citations
13. 13*

    Effects of the temperature and magnetic-field dependent coupling on the properties of QCD matter

    Li Yang🇨🇳 · Xin-jian Wen🇨🇳

    To reflect the asymptotic freedom in the thermal direction, a temperature-dependent coupling was proposed in the literature. We investigate its effect on QCD matter with and without strong magnetic fields. Compared with the fixed coupling constant, the running coupling leads to a drastic change in the dynamical quark mass, entropy density, sound velocity, and specific heat. The crossover transition of QCD matter at finite temperature is characterized by the pseudocritical temperature $T_{\mathrm{pc}}$, which is generally determined by the peak of the derivative of the quark condensate with respect to the temperature $d\varphi /dT$, or equivalently, by the derivative of the quark dynamical mass $dM/dT$. In a strong magnetic field, the temperature- and magnetic-field-dependent coupling $G(eB,T)$ was recently introduced to account for inverse magnetic catalysis. We propose an analytical relation between the two criteria $d\varphi /dT$ and $dM/dT$ and show a discrepancy between them in finding the pseudocritical temperature. The magnitude of the discrepancy depends on the behavior of $dG/dT$.

    hep-phPRD(2017)·5 citations
14. 14*

    Reconstruction of top-quark mass effects in Higgs pair production and other gluon-fusion processes

    Ramona Gröber🇬🇧 · Andreas Maier🇬🇧 · Thomas Rauh🇬🇧

    We propose a novel method for the treatment of top-quark mass effects in the production of $H^{(\ast )}$, $HH$, $HZ$ and $ZZ$ final states in gluon fusion. We show that it is possible to reconstruct the full top-quark mass dependence of the virtual amplitudes from the corresponding large-$m_t$ expansion and the non-analytic part of the amplitude near the top-quark threshold $\hat{s}=4m_t^2$ with a Padé ansatz. The reliability of our method is clearly demonstrated by a comparison with the recent NLO result for Higgs pair production with full top-quark mass dependence.

    hep-phJHEP(2018)·78 citations
15. 15*

    QED and QCD self-energy corrections through the loop-tree duality

    N. Selomit Ramírez-Uribe🇲🇽 · Roger J. Hernández-Pinto🇲🇽 · Germán Rodrigo🇪🇸

    The loop-tree duality (LTD) theorem establishes that loop contributions to scattering amplitudes can be computed through dual integrals, which are build from single cuts of the virtual diagrams. In order to build a complete LTD representation of a cross section and to achieve a local cancellation of singularities, it is crucial to include the renormalized self-energy corrections in an unintegrated form. In this document, we calculate the scalar functions related to the self-energy corrections in QED and QCD in the LTD formalism and extract explicitly their UV behaviour.

    hep-phJ.Phys.Conf.Ser.(2017)·7 citations
16. 16*

    Positivity bounds on gluon TMDs for hadrons of spin $\le$ 1

    Sabrina Cotogno🇳🇱 · Tom van Daal🇳🇱 · Piet J. Mulders🇳🇱

    We consider the transverse momentum dependent gluon distribution functions (called gluon TMDs) by studying the light-front gluon-gluon correlator, extending the results for unpolarized and vector polarized targets to also include tensor polarized targets -- the latter type of polarization is relevant for targets of spin $\ge 1$. The light-front correlator includes process-dependent gauge links to guarantee color gauge invariance. As from the experimental side the gluon TMDs are largely unknown, we present positivity bounds for combinations of leading-twist gluon distributions that may be used to estimate their maximal contribution to observables. Since the gluonic content of hadrons is particularly relevant in the small-$x$ kinematic region, we also study these bounds in the small-$x$ limit for the dipole-type gauge link structure using matrix elements of a single Wilson loop.

    hep-phJHEP(2017)·18 citations
17. 17*

    Freeze-out of baryon number in low-scale leptogenesis

    S. Eijima🇨🇭 · M. Shaposhnikov🇨🇭 · I. Timiryasov🇨🇭

    Low-scale leptogenesis provides an economic and testable description of the origin of the baryon asymmetry of the Universe. In this scenario, the baryon asymmetry of the Universe is reprocessed from the lepton asymmetry by electroweak sphaleron processes. Provided that sphalerons are fast enough to maintain equilibrium, the values of the baryon and lepton asymmetries are related to each other. Usually, this relation is used to find the value of the baryon asymmetry at the time of the sphaleron freeze-out. To put in other words, the formula which is valid only when the sphalerons are fast, is applied at the moment when they are actually switched off. In this paper, we examine the validity of such a treatment. To this end, we solve the full system of kinetic equations for low-scale leptogenesis. This system includes equations describing the production of the lepton asymmetry in oscillations of right-handed neutrinos, as well as a separate kinetic equation for the baryon asymmetry. We show that for some values of the model parameters, the corrections to the standard approach are sizeable. We also present a feasible improvement to the ordinary procedure, which accounts for these corrections.

    hep-phastro-ph.COJCAP(2017)·35 citations
18. 18*

    Spin Precession Experiments for Light Axionic Dark Matter

    Peter W. Graham🇺🇸 · David E. Kaplan🇺🇸 · Jeremy Mardon🇺🇸 · Surjeet Rajendran🇺🇸 · William A. Terrano🇩🇪 · Lutz Trahms🇩🇪 · Thomas Wilkason🇺🇸

    Axion-like particles are promising candidates to make up the dark matter of the universe, but it is challenging to design experiments that can detect them over their entire allowed mass range. Dark matter in general, and in particular axion-like particles and hidden photons, can be as light as roughly $10^{-22}\mathrm{eV}$ ($\sim 10^{-8}\mathrm{Hz}$), with astrophysical anomalies providing motivation for the lightest masses ("fuzzy dark matter"). We propose experimental techniques for direct detection of axion-like dark matter in the mass range from roughly $10^{-13}\mathrm{eV}$ ($\sim 10^2\mathrm{Hz}$) down to the lowest possible masses. In this range, these axion-like particles act as a time-oscillating magnetic field coupling only to spin, inducing effects such as a time-oscillating torque and periodic variations in the spin-precession frequency with the frequency and direction set by fundamental physics. We show how these signals can be measured using existing experimental technology, including torsion pendulums, atomic magnetometers, and atom interferometry. These experiments demonstrate a strong discovery capability, with future iterations of these experiments capable of pushing several orders of magnitude past current astrophysical bounds.

    hep-phastro-ph.COhep-exphysics.atom-phPRD(2018)·144 citations
19. 19*

    Light Dark Matter: Models and Constraints

    Simon Knapen🇺🇸 · Tongyan Lin🇺🇸 · Kathryn M. Zurek🇺🇸

    We study the direct detection prospects for a representative set of simplified models of sub-GeV dark matter (DM), accounting for existing terrestrial, astrophysical and cosmological constraints. We focus on dark matter lighter than an MeV, where these constraints are most stringent, and find three scenarios with accessible direct detection cross sections: (i) DM interacting via an ultralight kinetically mixed dark photon, (ii) a DM sub-component interacting with nucleons or electrons through a light scalar or vector mediator, and (iii) DM coupled with nucleons via a mediator heavier than ~ 100 keV.

    hep-phPRD(2017)·461 citations
20. 20*

    Measuring $|V_{td}|$ at LHC

    Ezequiel Alvarez🇦🇷 · Leandro Da Rold🇦🇷 · Mariel Estevez🇦🇷 · Jernej F. Kamenik🇸🇮

    We propose a direct measurement of the CKM element $V_{td}$ at the LHC. Taking profit of the imbalance between $d$ and $\bar{d}$ quark content in the proton, we show that a non-zero $V_{td}$ induces a charge asymmetry in the $tW$ associated production. The main backgrounds to this process, $t\bar{t}$ production, and $tW$ associated production mediated by $V_{tb}$, give charge symmetric contributions at leading order in QCD. Therefore, using specific kinematic features of the signal, we construct a charge asymmetry in the di-lepton final state which, due also to a reduction of systematic uncertainties in the asymmetry, is potentially sensitive to $V_{td}$ suppressed effects. In particular, using signal and background simulations up to detector level, we show that this new observable could improve the current direct upper bound on $|V_{td}|$ already with existing LHC data. We also project that $|V_{td}|$ values down to $\sim 10$ times the Standard Model prediction could be probed in the high luminosity phase of the LHC.

    hep-phhep-exPRD(2018)·16 citations
21. 21*

    Novel Astrophysical Probes of Light Millicharged Fermions through Schwinger Pair Production

    Mrunal Korwar🇮🇳 · Arun M. Thalapillil🇮🇳

    The extreme properties of neutron stars provide unique opportunities to put constraints on new particles and interactions. In this paper, we point out a few interesting ideas that place constraints on light millicharged fermions, with masses below around an eV, from neutron star astrophysics. The model independent bounds are obtained leveraging the fact that light millicharged fermions may be pair produced copiously via non-perturbative processes in the extreme electromagnetic environments of a neutron star, like a Magnetar. Magnetar energetics, magnetic field evolution and spin-down rates may all be influenced to various degrees by the presence of these millicharged particles.

    hep-phhep-exhep-thJHEP(2019)·14 citations
22. 22*

    Primordial non-Gaussianity and power asymmetry with quantum gravitational effects in loop quantum cosmology

    Tao Zhu🇨🇳 · Anzhong Wang🇺🇸 · Klaus Kirsten🇺🇸 · Gerald Cleaver🇺🇸 · Qin Sheng🇺🇸

    Loop quantum cosmology (LQC) provides a resolution of the classical big bang singularity in the deep Planck era. The evolution, prior to the usual slow-roll inflation, naturally generates excited states at the onset of the slow-roll inflation. It is expected that these quantum gravitational effects could leave its fingerprints on the primordial perturbation spectrum and non-Gaussianity, and lead to some observational evidences in the cosmic microwave background (CMB). While the impact of the quantum effects on the primordial perturbation spectrum has been already studied and constrained by current data, in this paper we continue studying such effects on the non-Gaussianity of the primordial curvature perturbations. In this paper, we present detailed and analytical calculations of the non-Gaussianity and show explicitly that the corrections due to quantum effects are in the same magnitude of the slow-roll parameters in the observable scales and thus are well within current observational constraints. Despite this, we show that the non-Gaussianity in the squeezed limit can be enhanced at superhorizon scales and further, these effects may yield a large statistical anisotropy on the power spectrum through the Erickcek-Kamionkowski-Carroll mechanism.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2018)·32 citations
23. 23*

    Can the graviton have a large mass near black holes?

    Jun Zhang🇨🇦 · Shuang-Yong Zhou🇬🇧

    The mass of the graviton, if nonzero, is usually considered to be very small, e.g. of the Hubble scale, from several observational constraints. In this paper, we propose a gravity model where the graviton mass is very small in the usual weak gravity environments, below all the current graviton mass bounds, but becomes much larger in the strong gravity regime such as a black hole's vicinity. For black holes in this model, significant deviations from general relativity emerge very close to the black hole horizon and alter the black hole quasi-normal modes, which can be extracted from the ringdown waveform of black hole binary mergers. Also, the enhancement of the graviton mass near the horizon can result in echoes in the late time ringdown, which can be verified in the upcoming gravitational wave observations of higher sensitivity.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2018)·43 citations
24. 24*

    Progress in computing parton distribution functions from the quasi-PDF approach

    Constantia Alexandrou🇨🇾 · Krzysztof Cichy🇩🇪 · Martha Constantinou🇺🇸 · Kyriakos Hadjiyiannakou🇨🇾 · Karl Jansen🇩🇪 · Haralambos Panagopoulos🇨🇾 · Aurora Scapellato🇨🇾 · Fernanda Steffens🇩🇪

    We discuss the current developments by the European Twisted Mass Collaboration in extracting parton distribution functions from the quasi-PDF approach. We concentrate on the non-perturbative renormalization prescription recently developed by us, using the RI${}^{\prime }$ scheme. We show results for the renormalization functions of matrix elements needed for the computation of quasi-PDFs, including the conversion to the $\overline{\mathrm{MS}}$ scheme, and for renormalized matrix elements. We discuss the systematic effects present in the $Z$-factors and the possible ways of addressing them in the future.

    ↳ hep-lathep-phEPJ Web Conf.(2018)·11 citations
25. 25*

    Thermal quarkonium physics in the pseudoscalar channel

    Y. Burnier🇨🇭 · H.-T. Ding🇨🇳 · O. Kaczmarek🇩🇪 · A.-L. Kruse🇩🇪 · M. Laine🇨🇭 · H. Ohno🇺🇸 · H. Sandmeyer🇩🇪

    The pseudoscalar correlator is an ideal lattice probe for thermal modifications to quarkonium spectra, given that it is not compromised by a contribution from a large transport peak. We construct a perturbative spectral function incorporating resummed thermal effects around the threshold and vacuum asymptotics above the threshold, and compare the corresponding imaginary-time correlators with continuum-extrapolated lattice data for quenched SU(3) at several temperatures. Modest differences are observed, which may originate from non-perturbative mass shifts or renormalization factors, however no resonance peaks are needed for describing the quenched lattice data for charmonium at and above T ~ 1.1Tc ~ 350 MeV. For comparison, in the bottomonium case a good description of the lattice data is obtained with a spectral function containing a single thermally broadened resonance peak.

    ↳ hep-lathep-phJHEP(2017)·53 citations
26. 26*

    $\mathcal{O}(10)M_{\odot }$ primordial black holes and string axion dark matter

    Keisuke Inomata🇯🇵 · Masahiro Kawasaki🇯🇵 · Kyohei Mukaida🇯🇵 · Yuichiro Tada🇯🇵 · Tsutomu T. Yanagida🇯🇵

    LIGO-Virgo collaboration has found black holes as heavy as $M\sim 30M_{\odot }$ through the detections of the gravitational waves emitted during their mergers. Primordial black holes (PBHs) produced by inflation could be an origin of such events. While it is tempting to presume that these PBHs constitute all Dark Matter (DM), there exists a number of constraints for PBHs with $\mathcal{O}(10)M_{\odot }$ which contradict with the idea of PBHs as all DM. Also, it is known that weakly interacting massive particle (WIMP) that is a common DM candidate is almost impossible to coexist with PBHs. These observations motivate us to pursue another candidate of DM. In this paper, we assume that the string axion solving the strong CP problem makes up all DM, and discuss the coexistence of string axion DM and inflationary PBHs for LIGO events.

    ↳ astro-ph.COhep-phPRD(2017)·13 citations
27. 27*

    Massless Spectra and Gauge Couplings at One-Loop on Non-Factorisable Toroidal Orientifolds

    Mikel Berasaluce-González🇩🇪 · Gabriele Honecker🇩🇪 · Alexander Seifert🇩🇪

    So-called `non-factorisable' toroidal orbifolds can be rewritten in a factorised form as a product of three two-tori by imposing an additional shift symmetry. This finding of Blaszczyk et al., arXiv:1111.5852, provides a new avenue to Conformal Field Theory methods, by which the vector-like massless matter spectrum - and thereby the type of gauge group enhancement on orientifold invariant fractional D6-branes - and the one-loop corrections to the gauge couplings in Type IIA orientifold theories can be computed in addition to the well-established chiral matter spectrum derived from topological intersection numbers among three-cycles. We demonstrate this framework for the ${\mathbb{Z}}_4\times \Omega \mathcal{R}$ orientifolds on the $A_3\times A_1\times B_2$-type torus. As observed before for factorisable backgrounds, also here the one-loop correction can drive the gauge groups to stronger coupling as demonstrated by means of a four-generation Pati-Salam example.

    ↳ hep-thhep-phNPB(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.