Tue·May 16, 2017Tuesday·May 16, 2017

1. 01*

   Hadronic Correlation Functions in the Random Instanton-dyon Ensemble

   Rasmus Larsen🇺🇸 · Edward Shuryak🇺🇸

   It is known since 1980's that the instanton-induced 't Hooft effective Lagrangian not only can solve the so called $U(1)a$ problem, by making the ${\eta }^{\prime }$ meson heavy etc, but it can also lead to chiral symmetry breaking. In 1990's it was demonstrated that, taken to higher orders, this Lagrangian correctly reproduces effective forces in a large set of hadronic channels, mesonic and baryonic ones. Recent progress in understanding gauge topology at finite temperatures is related with the so called {\em instanton-dyons}, the constituents of the instantons. Some of them, called $L$-dyons, possess the anti-periodic fermionic zero modes, and thus form a new version of the 't Hooft effective Lagrangian. This paper is our first study of a wide set of hadronic correlation function. We found that, at the lowest temperatures at which this approach is expected to be applicable, those may be well compatible with what is known about them based on phenomenological and lattice studies, provided $L$ and $M$ type dyons are strongly correlated.

   hep-phhep-latnucl-thPRD(2017)·6 citations
2. 02*

   Parity Violation and Rare Higgs Decays from a Dark Force

   Hooman Davoudiasl🇺🇸

   We outline the phenomenology of the "dark" $Z$, denoted by $Z_d$, which is a generalization of the "dark" photon hypothesis. Whereas the dark photon interacts with the Standard Model through kinetic mixing, $Z_d$ is assumed also to have mass-mixing with the $Z$ boson. In particular, we highlight the possibility of $Z_d$ contributions to low $Q^2$ parity violation measurements and rare Higgs decays $H\to Z{Z}_d\to 4\ell$, where $\ell$ is a charged lepton. The parity violation effects of a $Z_d$ with an intermediate mass $\sim 10-35$ GeV can in principle relieve the mild $\sim 1.8\sigma$ tension among various measurements of the weak mixing angle ${\theta }_W$. We briefly comment on the prospects for future parity violation experiments at low $Q^2$ to probe this scenario, which could have correlated signals in rare Higgs decays at the LHC.

   hep-phhep-ex0 citations
3. 03*

   Neutrino CP phases from Sneutrino Chaotic Inflation

   Kazunori Nakayama🇯🇵 · Fuminobu Takahashi🇯🇵 · Tsutomu T. Yanagida🇯🇵

   We study if the minimal sneutrino chaotic inflation is consistent with a flavor symmetry of the Froggatt-Nielsen type, to derive testable predictions on the Dirac and Majorana CP violating phases, $\delta$ and $\alpha$. For successful inflation, the two right-handed neutrinos, i.e., the inflaton and stabilizer fields, must be degenerate in mass. First we find that the lepton flavor symmetry structure becomes less manifest in the light neutrino masses in the seesaw mechanism, and this tendency becomes most prominent when right-handed neutrinos are degenerate. Secondly, the Dirac CP phase turns out to be sensitive to whether the shift symmetry breaking depends on the lepton flavor symmetry. When the flavor symmetry is imposed only on the stabilizer Yukawa couplings, distributions of the CP phases are peaked at $\delta \simeq \pm \pi /4,\pm 3\pi /4$ and $\alpha =0$, while the vanishing and maximal Dirac CP phases are disfavored. On the other hand, when the flavor symmetry is imposed on both the inflaton and stabilizer Yukawa couplings, it is rather difficult to explain the observed neutrino data, and those parameters consistent with the observation prefer the vanishing CP phases $\delta =0,\pi$ and $\alpha =0$.

   hep-phPLB(2017)·8 citations
4. 04*

   The LHC mass limits for the $SU(2{)}_{L+R}$ vector resonance triplet of a strong extension of the Standard model

   Mikulas Gintner🇨🇿 · Josef Juran🇨🇿

   In this paper, we derive the mass exclusion limits for the hypothetical vector resonances of a strongly interacting extension of the Standard model using the most recent upper bounds on the cross sections for various resonance production processes. The $SU(2{)}_{L+R}$ triplet of the vector resonances under consideration is embedded into the effective Lagrangian based on the non-linear sigma model with the $125$-GeV $SU(2{)}_{L+R}$ scalar singlet. No direct interactions of the vector resonance to the SM fermions are assumed. We find that among eleven processes considered in this paper only those where the vector resonances decay to $WW$ and $WZ$ provide the mass exclusion limit. Depending on the values of other parameters of the model the mass limit can be as low as 1 TeV.

   hep-phActa Phys.Polon.B(2017)·4 citations
5. 05*

   A Natural extra-dimensional origin for the LHCb anomalies

   Eugenio Megias🇪🇸 · Giuliano Panico🇪🇸 · Oriol Pujolas🇪🇸 · Mariano Quiros🇪🇸

   We study the possibility of explaining the recently found anomalies in B-meson decays within scenarios with a composite Higgs boson. This class of models provides a natural way to fit the experimental results, interpreting the anomalies as the result of the exchange of heavy vector resonances with electroweak quantum numbers. The anomalies are tightly related to deviations in Delta F = 2 transitions and to deformations of the Z and W couplings, whose size is of the order of the present experimental bounds. This leads to a very predictive scenario which could be soon tested at collider experiments.

   hep-ph5 citations
6. 06*

   Charged lepton flavour violation: precise background calculation and effective field theoretical interpretation

   Giovanni Marco Pruna🇨🇭

   This note reviews recent theoretical developments in the study of charged lepton flavour violation. The first part illustrates the status of precise next-to-leading order quantum electrodynamics calculations for the background of charged lepton flavour-violating processes, with a focus on the muonic "rare" and "radiative" decays. Phenomenological implications of these computations and their impact on present and future experiments will be discussed. The second part describes the recent progress in the effective field theory interpretation of charged lepton-flavour violating observables in connection with different energy scales. A systematic approach is briefly presented and applications on muonic and tauonic observables are reported. This note is submitted as part of the conference proceedings for "NuPhys2016: Prospects in Neutrino Physics".

   hep-ph1 citation
7. 07*

   Last Electroweak WIMP Standing: Pseudo-Dirac Higgsino Status and Compact Stars as Future Probes

   Rebecca Krall🇺🇸 · Matthew Reece🇺🇸

   Electroweak WIMPs are under intense scrutiny from direct detection, indirect detection, and collider experiments. Nonetheless the pure (pseudo-Dirac) higgsino, one of the simplest such WIMPs, remains elusive. We present an up-to-date assessment of current experimental constraints on neutralino dark matter. The strongest bound on pure higgsino dark matter currently may arise from AMS-02 measurements of antiprotons, though the interpretation of these results has sizable uncertainty. We discuss whether future astrophysical observations could offer novel ways to test higgsino dark matter, especially in the challenging regime with order MeV mass splitting between the two neutral higgsinos. We find that heating of white dwarfs by annihilation of higgsinos captured via inelastic scattering could be one useful probe, although it will require challenging observations of distant dwarf galaxies or a convincing case to be made for substantial dark matter content in Omega Centauri, a globular cluster that may be a remnant of a disrupted dwarf galaxy. White dwarfs and neutron stars give a target for astronomical observations that could eventually help to close the last, most difficult corner of parameter space for dark matter with weak interactions.

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

   Amplitudes, recursion relations and unitarity in the Abelian Higgs Model

   Ronald Kleiss🇳🇱 · Oscar Boher Luna🇳🇱

   The Abelian Higgs model forms an essential part of the electroweak standard model: it is the sector containing only Z and Higgs bosons. We present a diagram-based proof of the tree-level unitarity of this model inside the unitary gauge, where only physical degrees of freedom occur. We derive combinatorial recursion relations for off-shell amplitudes in the massless approximation, which allows us to prove the cancellation of the first two orders in energy of unitarity-violating high-energy behaviour for any tree-level amplitude in this model. We describe a deformation of the amplitudes by extending the physical phase space to at least 7 spacetime dimensions, which leads to on-shell recursion relations a la BCFW. These lead to a simple proof that all on-shell tree amplitudes obey partial-wave unitarity.

   hep-phJHEP(2017)·0 citations
9. 09*

   Jet Quenching at RHIC and LHC and the Fragmentation Function in Vacuum

   Gouranga C Nayak🇺🇸

   The value of the parton to hadron fragmentation function in QCD in vacuum (for example from proton-proton collisions at high energy colliders) is directly/indirectly used in the literature to study the jet quenching and the hadron production from quark-gluon plasma at RHIC and LHC. In this paper we show that this is not possible because, unlike the perturbative propagator in non-equilibrium QCD, the parton to hadron fragmentation function is a non-perturbative quantity in QCD and hence it is not possible to decompose the fragmentation function in non-equilibrium QCD into the vacuum part and the medium part.

   hep-phhep-latnucl-th11 citations
10. 10*

    Structures in the diffraction cone: the "break" and "dip" in high-energy proton-proton scattering

    László Jenkovszky🇺🇦 · István Szanyi🇺🇦

    Anticipating forthcoming publication by the TOTEM collaboration of low-t elastic scattering data at \sqrt{s}=13 and 2.76 TeV, hereby we emphasize the correlation between two prominent structures seen upon the otherwise exponential diffraction cone, namely a "break" staying fixed around t=-0.1 GeV^2 and a dip moving with energy logarithmically inwards; while at the ISR the two structures are separated by a distance of about 1~GeV^2, at the LHC the dip comes close to the periphery of the "break", thus affecting its parametrization. An unbiased disentangling and identification of the break at the LHC should account for this correlation.

    hep-phhep-exMod.Phys.Lett.A(2017)·11 citations
11. 11*

    Unambiguous cancellation of divergences of $H\to \gamma \gamma$ process via one W loop in unitary gauge: Gauge invariance in Dyson scheme and physical boundary condition

    Shi-Yuan Li🇨🇳 · Zong-Guo Si🇨🇳 · Xiao-Feng Zhang🇨🇳

    Following the thread of R. Gastmans, S. L. Wu and T. T. Wu, the calculation in the unitary gauge for the $H\to \gamma \gamma$ process via one W loop is repeated, but without the specific choice of the independent loop momentum for the Feynman diagrams. This is based on the original 'Dyson scheme' provided in Dyson's classical paper. I.e., the original integrations on all propagator momenta are kept, not expressed by the specified independent loop momentum. Correspondingly, the 4-dimension $\delta$ function at each vertex in which the 4-momentum conservation is embedded, is retained. Together with the Ward identity of the W-W-photon vertex, the 4-momentum conservation of each vertex guarantee the cancellation of all divergent integrals worse than logarithmic without any uncertainty or ambiguity, with any shift of integrated momentum eschewed. The calculation is in 4-dimension Minkowski phase space and without any help of regularization. The resulting integrals are to the most logarithmically divergent, hence is invariant for various setting of the independent loop momentum and any of its shift. At last the logarithmically divergent symmetric (tensor) integration is determined by the boundary condition at infinity in momentum space inherent of the free Feynman propagator, and the gauge (both $SU(2)\times U_Y(1)$ and $U_{em}(1)$) invariant finite result can be obtained without the introduction of the 'Dyson subtraction'. The physical boundary conditions at infinity of phase space can make sense in many problems.

    hep-ph5 citations
12. 12*

    Electroweak Baryogenesis driven by Extra Top Yukawa Couplings

    Kaori Fuyuto🇺🇸 · Wei-Shu Hou🇹🇼 · Eibun Senaha🇰🇷

    We study electroweak baryogenesis driven by the top quark in a general two Higgs doublet model with flavor-changing Yukawa couplings, keeping the Higgs potential $CP$ invariant. With Higgs sector couplings and the additional top Yukawa coupling ${\rho }_{tt}$ all of $\mathcal{O}$(1), one naturally has sizable $CP$ violation that fuels the cosmic baryon asymmetry. Even if ${\rho }_{tt}$ vanishes, the favor-changing coupling ${\rho }_{tc}$ can still lead to successful baryogenesis. Phenomenological consequences such as $t\to ch$, $\tau \to \mu \gamma$, electron electric dipole moment, $h\to \gamma \gamma$, and $hhh$ coupling are discussed.

    hep-phPLB(2018)·120 citations
13. 13*

    $J/\Psi$ Photoproduction in Peripheral AA Collisions

    M. B. Gay Ducati🇧🇷 · S. Martins🇧🇷

    The exclusive photoproduction of the heavy vector mesons $J/\Psi$ is investigated in the context of peripheral lead-lead collisions for the energies available at the LHC, $\sqrt{s}=2.76$ TeV and $\sqrt{s}=5.02$ TeV. Using the light-cone color dipole formalism, it was calculated the rapidity distribution in two centrality bins 50\%-70\% and 70\%-90\% in order to evaluate its robustness in extrapolating down to smaller impact parameter. It is introduced a modified photon flux, without change in the photonuclear cross section in relation to the ultraperipheral (UPC) case. Results were obtained for the two regions analized, which presented a maximum difference of 27\% in frontal rapidity for the two regions. Comparing the results for $\sqrt{s}=2.76$ TeV and $\sqrt{s}=5.02$ TeV, it was verified an increase of approximately half the one obtained in ultraperipheral regime in the central rapidity region.

    hep-phPRD(2017)·15 citations
14. 14*

    Hadronic Weak Decay ${\mathcal{B}}_b({\frac{1}{2}}^{+})\to \mathcal{B}({\frac{1}{2}}^{+},{\frac{3}{2}}^{+})+V$

    Fayyazuddin🇵🇰 · M. Jamil Aslam🇵🇰

    It is shown that for the effective Lagrangian with factorization ansatz considered here, the two body hadronic decay ${\mathcal{B}}_b({\frac{1}{2}}^{+})\to \mathcal{B}({\frac{1}{2}}^{+},{\frac{3}{2}}^{+})+V$, for ${\mathcal{B}}_b({\frac{1}{2}}^{+})$ belonging to the representation $\bar{3}$, only allowed decay channel is ${\mathcal{B}}_b({\frac{1}{2}}^{+})\to \mathcal{B}({\frac{1}{2}}^{+})+V$, where $\mathcal{B}({\frac{1}{2}}^{+})$ belongs to the representation $8$ of $SU(3)$. However, for ${\mathcal{B}}_b({\frac{1}{2}}^{+})$ belonging to the sextet representation $6$, the allowed decay channels are ${\mathcal{B}}_b({\frac{1}{2}}^{+})\to \mathcal{B}({\frac{1}{2}}^{+},{\frac{3}{2}}^{+})+V$, where $\mathcal{B}({\frac{1}{2}}^{+})$ and $\mathcal{B}({\frac{3}{2}}^{+})$ belongs to the octet representation $8^{\prime }$ and the decuplet $10$ of $SU(3)$, respectively. The decay channel ${\mathcal{B}}_b({\frac{1}{2}}^{+})\to \mathcal{B}({\frac{1}{2}}^{+})+V$ is analyzed in detail. The decay rate ($\Gamma$) and the asymmetry parameters $\alpha ,{\alpha }^{\prime },\beta ,\gamma$ and ${\gamma }^{\prime }$ are expressed in terms of four amplitudes. In particular for the decay ${\Lambda }_b\to \Lambda +J/\psi$ it is shown that within the factorization framework, using heavy quark spin symmetry, the decay rate and the asymmetry parameters can be expressed in terms of two form factors $F_1$ and $F_2/F_1$, which are to be evaluated in some model. For other heavy quarks belonging to the triplet and sextet representation, the results can be easily obtained by using $SU(3)$ symmetry and phase space factor. Finally, the decay ${\Omega }_b^{-}\to {\Omega }^{-}+J/\psi$ is analyzed within the factorization framework. It is shown that the asymmetry parameter $\alpha$ in this particular decay is zero. The branching ratio obtained in the first approximation is compared with the experimental value.

    hep-phPRD(2017)·12 citations
15. 15*

    Three-loop massive tadpoles and polylogarithms through weight six

    B.A. Kniehl🇩🇪 · A.F. Pikelner🇩🇪 · O.L. Veretin🇩🇪

    We evaluate the three-loop massive vacuum bubble diagrams in terms of polylogarithms up to weight six. We also construct the basis of irrational constants being harmonic polylgarithms of arguments $e^{ki\pi /3}$.

    hep-phhep-thJHEP(2017)·37 citations
16. 16*

    Effective Field Theory for Higgs properties parametrisation: the transverse momentum spectrum case

    Massimiliano Grazzini🇨🇭 · Agnieszka Ilnicka🇨🇭 · Michael Spira🇨🇭 · Marius Wiesemann🇨🇭

    After the Higgs boson discovery, LHC can be used as a precision machine to explore its properties. Indeed, in case new resonances will not be found, the only access to New Physics would be via measuring small deviations from the SM predictions. A consistent approach is provided by a bottom-up Effective Field Theory, with dimension six operators built of Standard Model fields (SMEFT). We discuss how this approach works in case of the transverse momentum spectrum of the Higgs particle. In our calculation we augmented the Standard Model with three additional operators describing modifications of the top and bottom Yukawa couplings, and a point-like Higgs coupling to gluons. Based on recently presented resummed transverse-momentum spectra including these operators at NLL+NLO accuracy,which we recently presented in Ref [1], in this note we show the extension of the calculation to NNLL+NNLO. We find that such modifications, while affecting the total rate within the current uncertainties, can lead to significant distortions of the spectrum. Additionally, through significant reduction of the scale uncertainty we improve the sensitivity to the new operators.

    hep-ph14 citations
17. 17*

    Spin-3/2 dark matter in a simple $t$-channel model

    Mohammed Omer Khojali🇿🇦 · Ashok Goyal🇮🇳 · Mukesh Kumar🇿🇦 · Alan S. Cornell🇿🇦

    We consider a spin-3/2 fermionic dark matter (DM) particle interacting with the Standard Model quarks through the exchange of a charged and coloured scalar or vector mediator in a simple $t$-channel model. It is found that for the vector mediator case, almost the entire parameter space allowed by the observed relic density is already ruled out by the direct detection LUX data. No such bounds exist on the interaction mediated by scalar particles. Monojet + missing energy searches at the Large Hadron Collider provide the most stringent bounds on the parameters of the model for this case. The collider bounds put a lower limit on the allowed DM masses.

    hep-phEPJC(2018)·11 citations
18. 18*

    Cosmic matter from dark electroweak phase transition with neutrino mass generation

    Pei-Hong Gu🇨🇳

    We consider a dark electroweak phase transition, during which a baryon asymmetry in the dark neutrons and an equal lepton asymmetry in the dark Dirac neutrinos can be simultaneously induced by the CP-violating reflection of the dark fermions off the expanding dark Higgs bubbles. The Yukawa couplings for generating the ordinary Majorana neutrino masses can partially convert the dark lepton asymmetry to an ordinary baryon asymmetry in association with the ordinary sphaleron processes. The dark neutron can have a determined mass to serve as a dark matter particle. By further imposing a proper mirror symmetry, the Majorana neutrino mass matrix can have a form of linear seesaw while its Dirac CP phase can provide a unique source for the required CP violation.

    hep-phPRD(2017)·10 citations
19. 19*

    Distinct signals of the gauge-Higgs unification in $e^{+}{e}^{-}$ collider experiments

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

    Effects of Kaluza-Klein excited neutral vector bosons ($Z^{\prime }$ bosons) in the gauge-Higgs unification on $e^{+}{e}^{-}\to \bar{q}q,{\ell }^{+}{\ell }^{-}$ cross sections are studied, particularly in future $e^{+}{e}^{-}$ collider experiments with polarized beams. Significant deviations in the energy and polarization dependence in $\sigma ({\mu }^{+}{\mu }^{-})$, the lepton forward-backward asymmetry, $R_b(\mu )\equiv \sigma (\bar{b}b)/\sigma ({\mu }^{+}{\mu }^{-})$ and the left-right asymmetry from the standard model are predicted.

    hep-phPLB(2017)·42 citations
20. 20*

    Golden Littlest Seesaw

    Gui-Jun Ding🇨🇳 · Stephen F. King🇬🇧 · Cai-Chang Li🇨🇳

    We propose and analyse a new class of Littlest Seesaw models, with two right-handed neutrinos in their diagonal mass basis, based on preserving the first column of the Golden Ratio mixing matrix. We perform an exhaustive analysis of all possible remnant symmetries of the group $A_5$ which can be used to enforce various vacuum alignments for the flavon controlling solar mixing, for two simple cases of the atmospheric flavon vacuum alignment. The solar and atmospheric flavon vacuum alignments are enforced by {\em different} remnant symmetries. We examine the phenomenological viability of each of the possible Littlest Seesaw alignments in $A_5$, which preserve the first column of the Golden ratio mixing matrix, using figures and extensive tables of benchmark points and comparing our predictions to a recent global analysis of neutrino data. We also repeat the analysis for an alternative form of Golden Ratio mixing matrix.

    hep-phNPB(2017)·18 citations
21. 21*

    Higgs Pair Production at NLO QCD for CP-violating Higgs Sectors

    R. Grober🇬🇧 · M. Muhlleitner🇩🇪 · M. Spira🇨🇭

    Higgs pair production through gluon fusion is an important process at the LHC to test the dynamics underlying electroweak symmetry breaking. Higgs sectors beyond the Standard Model (SM) can substantially modify this cross section through novel couplings not present in the SM or the on-shell production of new heavy Higgs bosons that subsequently decay into Higgs pairs. CP violation in the Higgs sector is important for the explanation of the observed matter-antimatter asymmetry through electroweak baryogenesis. In this work we compute the next-to-leading order (NLO) QCD corrections in the heavy top quark limit, including the effects of CP violation in the Higgs sector. We choose the effective theory (EFT) approach, which provides a rather model-independent way to explore New Physics (NP) effects by adding dimension-6 operators, both CP-conserving and CP-violating ones, to the SM Lagrangian. Furthermore, we perform the computation within a specific UV-complete model and choose as benchmark model the general 2-Higgs-Doublet Model with CP violation, the C2HDM. Depending on the dimension-6 coefficients, the relative NLO QCD corrections are affected by several per cent through the new CP-violating operators. This is also the case for SM-like Higgs pair production in the C2HDM, while the relative QCD corrections in the production of heavier C2HDM Higgs boson pairs deviate more strongly from the SM case. The absolute cross sections both in the EFT and the C2HDM can be modified by more than an order of magnitude. In particular, in the C2HDM the resonant production of Higgs pairs can by far exceed the SM cross section.

    hep-phNPB(2017)·76 citations
22. 22*

    QCD Corrections to the Color-singlet $J/\psi$ Production in Deeply Inelastic Scattering at HERA

    Zhan Sun🇨🇳 · Hong-Fei Zhang🇨🇳

    We present the first study of the QCD corrections to the color-singlet (CS) $J/\psi$ production in deeply inelastic $ep$ scattering at HERA. The $K$-factor ranges from $0.85$ to $2.38$ in the kinematic regions we study. In low transverse momentum regions, the $K$-factors is even smaller, and close to 1, which indicates good convergence of the perturbative expansion. With the QCD corrections, the CS cross section is still below the data. At least at QCD next-to-leading order, the color-octet mechanism is necessary to describe the data.

    hep-phhep-exPRD(2017)·23 citations
23. 23*

    Construction of lepton mass matrices and TeV-scale phenomenology in the minimal left-right symmetric model

    Chang-Hun Lee🇺🇸

    We develop a systematic procedure of constructing lepton mass matrices that satisfy all the experimental constraints in the light lepton sector of the minimal left-right symmetric model with type-I seesaw dominance. This method is unique since it is applicable to the most general cases of type-I seesaw with complex electroweak vacuum expectation values in the model. With this method, we investigate the TeV-scale phenomenology in the normal hierarchy without fine-tuning of model parameters, focusing on the charged lepton flavour violation, neutrinoless double beta decay, and electric dipole moments of charged leptons. We examine the predictions for typical ranges of associated observables such as branching ratios of rare lepton decays, and study how those experimental constraints affect the model parameter space. The most notable result is that the regions of parameter space that allow small light neutrino masses have been constrained by the present experimental bounds from charged lepton flavour violation. Furthermore, we also find that the mass of the lightest heavy neutrino should be relatively small in order to satisfy those experimental constraints.

    hep-ph0 citations
24. 24*

    Window for preferred axion models

    Luca Di Luzio🇬🇧 · Federico Mescia🇪🇸 · Enrico Nardi🇮🇹

    We discuss phenomenological criteria for defining "axion windows", namely regions in the parameter space of the axion-photon coupling where realistic models live. Currently, the boundaries of this region depend on somewhat arbitrary criteria, and it would be highly desirable to specify them in terms of precise phenomenological requirements. We first focus on hadronic axion models within post-inflationary scenarios, in which the initial abundance of the new vectorlike quarks $Q$ is thermal. We classify their representations $R_Q$ by requiring that $i)$ the $Q$ are sufficiently short lived to avoid issues with long-lived strongly interacting relics, $ii)$ the theory remains weakly coupled up to the Planck scale. The more general case of multiple $R_Q$ is also studied, and the absolute upper and lower bounds on the axion-photon coupling as a function of the axion mass is identified. Pre-inflationary scenarios in which the axion decay constant remains bounded as $f_a\le 5\cdot 10^{11}$GeV allow for axion-photon couplings only about 20% larger. Realistic Dine-Fischler-Srednicki-Zhitnitsky type of axion models also remain encompassed within the hadronic axion window. Some mechanisms that can allow to enhance the axion-photon coupling to values sizeably above the preferred window are discussed.

    hep-phPRD(2017)·188 citations
25. 25*

    The Energy Distribution of Subjets and the Jet Shape

    Zhong-Bo Kang🇺🇸 · Felix Ringer🇺🇸 · Wouter J. Waalewijn🇳🇱

    We present a framework that describes the energy distribution of subjets of radius $r$ within a jet of radius $R$. We consider both an inclusive sample of subjets as well as subjets centered around a predetermined axis, from which the jet shape can be obtained. For $r\ll R$ we factorize the physics at angular scales $r$ and $R$ to resum the logarithms of $r/R$. For central subjets, we consider both the standard jet axis and the winner-take-all axis, which involve double and single logarithms of $r/R$, respectively. All relevant one-loop matching coefficients are given, and an inconsistency in some previous results for cone jets is resolved. Our results for the standard jet shape differ from previous calculations at next-to-leading logarithmic order, because we account for the recoil of the standard jet axis due to soft radiation. Numerical results are presented for an inclusive subjet sample for $pp\to \mathrm{jet}+X$ at next-to-leading order plus leading logarithmic order.

    hep-phhep-exnucl-exnucl-thJHEP(2017)·74 citations
26. 26*

    Decay of Ultralight Axion Condensates

    Joshua Eby🇺🇸 · Michael Ma🇺🇸 · Peter Suranyi🇺🇸 · L.C.R. Wijewardhana🇺🇸

    Axion particles can form macroscopic condensates, whose size can be galactic in scale for models with very small axion masses $m\sim 10^{-22}$ eV, and which are sometimes referred to under the name of Fuzzy Dark Matter. Many analyses of these condensates are done in the non-interacting limit, due to the weakness of the self-interaction coupling of axions. We investigate here how certain results change upon inclusion of these interactions, finding a decreased maximum mass and a modified mass-radius relationship. Further, these condensates are, in general, unstable to decay through number-changing interactions. We analyze the stability of galaxy-sized condensates of axion-like particles, and sketch the parameter space of stable configurations as a function of a binding energy parameter. We find a strong lower bound on the size of Fuzzy Dark Matter condensates which are stable to decay, with lifetimes longer than the age of the universe.

    hep-phastro-ph.COJHEP(2018)·46 citations
27. 27*

    Neutrino Masses and Absence of Flavor Changing Interactions in the 2HDM from Gauge Principles

    Miguel D. Campos🇩🇪 · D. Cogollo🇧🇷 · Manfred Lindner🇩🇪 · T. Melo🇧🇷 · Farinaldo S. Queiroz🇩🇪 · Werner Rodejohann🇩🇪

    We propose several Two Higgs Doublet Models with the addition of an Abelian gauge group which free the usual framework from flavor changing neutral interactions and explain neutrino masses through the seesaw mechanism. We discuss the kinetic and mass-mixing gripping phenomenology which encompass several constraints coming from atomic parity violation, the muon anomalous magnetic moment, rare meson decays, Higgs physics, LEP precision data, neutrino-electron scattering, low energy accelerators and LHC probes.

    hep-phJHEP(2017)·86 citations
28. 28*

    Nonrelativistic Yang-Mills Theory for a Naturally Light Higgs Boson

    Laure Berthier🇩🇰 · Kevin T. Grosvenor🇩🇰 · Ziqi Yan🇺🇸

    We continue the study of the nonrelativistic short-distance completions of a naturally light Higgs, focusing on the interplay between the gauge symmetries and the polynomial shift symmetries. We investigate the naturalness of nonrelativistic scalar quantum electrodynamics with a dynamical critical exponent $z=3$ by computing leading power law divergences to the scalar propagator in this theory. We find that power law divergences exhibit a more refined structure in theories that lack boost symmetries. Finally, in this toy model, we show that it is possible to preserve a fairly large hierarchy between the scalar mass and the high energy naturalness scale across 7 orders of magnitude, while accommodating a gauge coupling of order 0.1.

    ↳ hep-thhep-phPRD(2017)·1 citation
29. 29*

    New Prospects for Detecting High-Energy Neutrinos from Nearby Supernovae

    Kohta Murase (PSU)🇺🇸

    Neutrinos from supernovae (SNe) are crucial probes of explosive phenomena at the deaths of massive stars and neutrino physics. High-energy neutrinos are produced through hadronic processes by cosmic rays, which are accelerated during interaction between the supernova (SN) ejecta and circumstellar material (CSM). Recent observations of extragalactic SNe have revealed that a dense CSM is commonly expelled by the progenitor star. We provide new quantitative predictions of time-dependent high-energy neutrino emission from diverse types of SNe. We show that IceCube and KM3Net can detect about 1000 events from a SN II-P (and about 300000 events from a SN IIn) at a distance of 10 kpc. The new model also enables us to critically optimize the time window for dedicated searches for nearby SNe. A successful detection will give us a multienergy neutrino view of SN physics and new opportunities to study neutrino properties, as well as clues to the cosmic-ray origin. GeV-TeV neutrinos may also be seen by KM3Net, Hyper-Kamiokande, and PINGU.

    ↳ astro-ph.HEastro-ph.SRhep-phnucl-thPRD(2018)·111 citations
30. 30*

    Primordial Black Hole production in Critical Higgs Inflation

    Jose Maria Ezquiaga🇪🇸 · Juan Garcia-Bellido🇪🇸 · Ester Ruiz Morales🇪🇸

    Primordial Black Holes (PBH) arise naturally from high peaks in the curvature power spectrum of near-inflection-point single-field inflation, and could constitute today the dominant component of the dark matter in the universe. In this letter we explore the possibility that a broad spectrum of PBH is formed in models of Critical Higgs Inflation (CHI), where the near-inflection point is related to the critical value of the RGE running of both the Higgs self-coupling $\lambda (\mu )$ and its non-minimal coupling to gravity $\xi (\mu )$. We show that, for a wide range of model parameters, a half-domed-shaped peak in the matter spectrum arises at sufficiently small scales that it passes all the constraints from large scale structure observations. The predicted cosmic microwave background spectrum at large scales is in agreement with Planck 2015 data, and has a relatively large tensor-to-scalar ratio that may soon be detected by B-mode polarization experiments. Moreover, the wide peak in the power spectrum gives an approximately lognormal PBH distribution in the range of masses $0.01-100M_{\odot }$, which could explain the LIGO merger events, while passing all present PBH observational constraints. The stochastic background of gravitational waves coming from the unresolved black-hole-binary mergers could also be detected by LISA or PTA. Furthermore, the parameters of the CHI model are consistent, within $2\sigma$, with the measured Higgs parameters at the LHC and their running. Future measurements of the PBH mass spectrum could allow us to obtain complementary information about the Higgs couplings at energies well above the EW scale, and thus constrain new physics beyond the Standard Model.

    ↳ astro-ph.COgr-qchep-phhep-thPLB(2018)·331 citations
31. 31*

    Modulus stabilization in a non-flat warped braneworld scenario

    Indrani Banerjee🇮🇳 · Soumitra SenGupta🇮🇳

    The stability of the modular field in a warped brane world scenario has been a subject of interest for a long time. Goldberger \& Wise ( GW ) proposed a mechanism to achieve this by invoking a massive scalar field in the bulk space-time neglecting the back-reaction. In this work, we examine the possibility of stabilizing the modulus without bringing in any external scalar field. We show that instead of flat 3-branes as considered in Randall-Sundrum ( RS ) warped braneworld model, if one considers a more generalized version of warped geometry with de-Sitter 3-brane, then the brane vacuum energy automatically leads to a modulus potential with a metastable minimum. Our result further reveals that in this scenario the gauge hierarchy problem can also be resolved for appropriate choice of brane cosmological constant.

    ↳ hep-thgr-qchep-phEPJC(2017)·15 citations
32. 32*

    Ultrahigh-energy Cosmic-ray Nuclei from Black Hole Jets: Recycling Galactic Cosmic Rays through Shear Acceleration

    Shigeo S. Kimura🇺🇸 · Kohta Murase🇺🇸 · B. Theodore Zhang🇨🇳

    We perform Monte Carlo simulations of transrelativistic shear acceleration dedicated to a jet-cocoon system of active galactic nuclei. A certain fraction of galactic cosmic rays in a halo is entrained, and sufficiently high-energy particles can be injected to the reacceleration process and further accelerated up to 100 EeV. We show that the shear reacceleration mechanism leads to a hard spectrum of escaping cosmic rays, $d{L}_E/dE\propto E^{-1}-E^0$, distinct from a conventional $E^{-2}$ spectrum. The supersolar abundance of ultrahigh-energy nuclei is achieved due to injections at TeV-PeV energies. As a result, we find that the highest-energy spectrum and mass composition can be reasonably explained by our model without contradictions with the anisotropy data.

    ↳ astro-ph.HEastro-ph.COhep-phnucl-thPRD(2018)·82 citations
33. 33*

    Revisiting arithmetic solutions to the $W=0$ condition

    Keita Kanno🇯🇵 · Taizan Watari🇯🇵

    The gravitino mass is expected not to be much smaller than the Planck scale for a large fraction of vacua in flux compactifications. There is no continuous parameter to tune even by hand, and it seems that the gravitino mass can be small only as a result of accidental cancellation among period integrals weighted by integer-valued flux quanta. DeWolfe et.al. (2005) proposed to pay close attention to vacua where the Hodge decomposition is possible within a number field, so that the precise cancellation takes place as a result of algebra. We focus on a subclass of those vacua---those with complex multiplications---and explore more on the idea in this article. It turns out, in Type IIB compactifications, that those vacua admit non-trivial supersymmetric flux configurations if and only if the reflex field of the Weil intermediate Jacobian is isomorphic to the quadratic imaginary field generated by the axidilaton vacuum expectation value. We also found that flux statistics is highly enriched on such vacua, as F-term conditions become linearly dependent.

    ↳ hep-thhep-phPRD(2017)·14 citations
34. 34*

    Observation of Narrow $N^{+}(1685)$ and $N^0(1685)$ Resonances in $\gamma N\to \eta \pi N$ Reactions

    V. Kuznetsov · F. Mammoliti · F. Tortorici · V. Bellini · V. Brio · A. Gridnev · N. Kozlenko · G. Russo · A.Spatafora · M.L.Sperduto · V.Sumachev · C.Sutera

    Observation of a narrow structure at $W\sim 1.68$ GeV in the excitation functions of some photon- and pion-induced reactions may signal a new narrow isospin-1/2 $N(1685)$ resonance. New data on the $\gamma N\to \pi \eta N$ reactions from GRAAL seems to reveal the signals of both $N^{+}(1685)$ and $N^0(1685)$ resonances.

    ↳ nucl-exhep-exhep-phnucl-thJETP Lett.(2017)·14 citations
35. 35*

    Secondary isocurvature perturbations from acoustic reheating

    Atsuhisa Ota🇯🇵 · Masahide Yamaguchi🇯🇵

    The superhorizon (iso)curvature perturbations are conserved if the following conditions are satisfied: (i) (each) non adiabatic pressure perturbation is zero, (ii) the gradient terms are ignored, that is, at the leading order of the gradient expansion (iii) (each) total energy momentum tensor is conserved. We consider the case with the violation of the last two requirements and discuss the generation of secondary isocurvature perturbations during the late time universe. Second order gradient terms are not necessarily ignored even if we are interested in the long wavelength modes because of the convolutions which may pick products of short wavelength perturbations up. We then introduce second order conserved quantities on superhorizon scales under the conditions (i) and (iii) even in the presence of the gradient terms by employing the full second order cosmological perturbation theory. We also discuss the violation of the condition (iii), that is, the energy momentum tensor is conserved for the total system but not for each component fluid. As an example, we explicitly evaluate second order heat conduction between baryons and photons due to the weak Compton scattering, which dominates the period just before recombination. We show that such secondary effects can be recast into the isocurvature perturbations on superhorizon scales if the local type primordial non Gaussianity exists a priori.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2018)·6 citations
36. 36*

    QCD Results from HERA

    Daniel Britzger (for the H1 and ZEUS Collaborations)🇩🇪

    New results on the measurements of the hadronic final state in neutral-current deep-inelastic scattering at HERA are presented. A combination of reduced charm and beauty cross sections is presented and the masses of the heavy quarks are determined to $m_c=1290{(}_{-53}^{+78})\mathrm{MeV}$ and $m_b=4049{(}_{-118}^{+138})\mathrm{MeV}$. The measurement of the production of prompt photons accompanied by a jet provides a precise test of QCD predictions. Measurements of jet production cross sections are presented and compared for the first time to next-to-next-to-leading order predictions (NNLO). The strong coupling constant is determined from inclusive jet and dijet production cross sections using NNLO predictions to ${\alpha }_s(m_Z)=0.1157(6{)}_{\exp }{(}_{-26}^{+31}{)}_{\mathrm{th}}$.

    ↳ hep-exhep-ph2 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.