Wed·Sep 5, 2018Wednesday·September 5, 2018

1. 01*

   Strong interaction between kaons in the reactions e+ e- --> K+ K- gamma and e+ e- --> K0 K0bar gamma

   L. Lesniak🇵🇱 · F. Sobczuk🇵🇱 · M. Silarski🇵🇱 · F. Morawski🇵🇱

   A theoretical model of the reactions e+ e- --> K+ K- gamma and e+ e- --> K0 K0bar gamma has been derived. The strong interaction between kaons is taken into account using a general form of the K Kbar scattering amplitude. It is shown that some models formulated in the past are particular cases of the present approach. The formulae for the K Kbar effective mass dependence of the differential cross section as well as for the angular kaon and photon distributions and for the branching fractions of the phi(1020)--> K+ K- gamma and phi(1020)--> K0 K0bar gamma decays have been obtained. We present numerical results for the functions entering into transition amplitudes, K Kbar effective mass distributions, total cross sections, and branching fractions. Finally, the model is generalized to treat other reactions with two pseudoscalar mesons accompanying a photon in the final state.

   hep-phPRD(2018)·0 citations
2. 02*

   Anisotropic pressure in strange quark matter in the presence of a strong nonuniform magnetic field

   A. A. Isayev🇺🇦

   Thermodynamic properties of strange quark matter (SQM) in a nonuniform magnetic field are studied within the phenomenological MIT bag model under the charge neutrality and beta equilibrium conditions, relevant to the interior of strange quark stars. The spatial dependence of the magnetic field strength is modeled by the dependence on the baryon chemical potential in the exponential and power forms. The total energy density, longitudinal and transverse pressures in magnetized SQM are found as functions of the baryon chemical potential. It is clarified that the central magnetic field strength in a strange quark star is bound from above by the critical value at which the derivative of the longitudinal pressure with respect to the baryon chemical potential vanishes first somewhere in the interior of a star under varying the central field. Above this upper bound, the instability along the magnetic field is developed in magnetized SQM. The change in the form of the dependence of the magnetic field strength on the baryon chemical potential between the exponential and power ones has a nonnegligible effect on the critical magnetic field strength while the variation of the bag pressure within the absolute stability window for magnetized SQM has a little effect on the critical field.

   hep-phastro-ph.HEPRD(2018)·7 citations
3. 03*

   Focus Point Gauge Mediation without a Severe Fine-tuning

   Tsutomu T. Yanagida🇯🇵 · Norimi Yokozaki🇯🇵

   We consider focus point gauge mediation within the framework of the next-to-minimal supersymmetric standard model, which substantially reduces the degree of fine-tuning for the electroweak symmetry breaking. The milder fine-tuning is realized by a messenger field in the adjoint representation of $SU(5)$ gauge group with $SU(3{)}_c$ octet being heavy. Our model has a simple ultraviolet completion. The fine-tuning measure $\Delta$ can be as small as 40-50 without any contradiction with LHC constraints.

   hep-phhep-exJHEP(2018)·2 citations
4. 04*

   Symmetries in subatomic multi-quark systems

   J.D. Vergados (Physics Department, University of Ioannina, Ioannina, Greece)🇬🇷 · D. Strottman (LANL, Los Alamos, NM, USA)🇺🇸

   We discus the role of QCD (Quantum Chromodynamics) to low energy phenomena involving the color-spin symmetry of the quark model. We then combine it with orbital and isospin symmetry to obtain wave functions with the proper permutation symmetry, focusing on multi quark systems.

   hep-phIJMPE(2018)·0 citations
5. 05*

   Advancing LHC Probes of Dark Matter from the Inert 2-Higgs Doublet Model with the Mono-jet Signal

   A. Belyaev🇬🇧 · T. R. Fernandez Perez Tomei🇧🇷 · P. G. Mercadante🇧🇷 · C. S. Moon🇰🇷 · S. Moretti🇬🇧 · S. F. Novaes🇧🇷 · L. Panizzi🇸🇪 · F. Rojas🇨🇱 · M. Thomas🇬🇧

   The inert 2-Higgs Doublet Model (i2HDM) is a well-motivated minimal consistent Dark Matter (DM) model, but it is rather challenging to test at the Large Hadron Collider (LHC) in the parameter space allowed by relic density and DM direct detection constraints. This is especially true when considering the latest XENON 1T data on direct DM searches which we use here to present the best current combined limit on the i2HDM parameter space. In this analysis, we present prospects to advance the exploitation of DM mono-jet signatures from the i2HDM at the LHC, by emphasising that a shape analysis of the missing transverse momentum distribution allows one to sizably improve the LHC discovery potential. As a key element of our analysis, we explore the validity of using an effective vertex, $ggH$, for the coupling of the Higgs boson to gluons using a full one-loop computation. We have found sizeable differences between the two approaches, especially in the high missing transverse momentum region, and incorporated the respective K-factors to obtain the correct kinematical distributions. As a result, we delineate a realistic search strategy and present the improved current and projected LHC sensitivity to the i2HDM parameter space.

   hep-phPRD(2019)·82 citations
6. 06*

   Bound state formation in the $DDK$ system

   A. Martinez Torres🇧🇷 · K. P. Khemchandani🇨🇳 · Li-Sheng Geng🇨🇳

   We study the $DDK$ system in a coupled channel approach, by including $D{D}_s\eta$ and $D{D}_s\pi$, and find that the dynamics involved in the system forms a bound state with isospin $1/2$ and mass $4140$ MeV when one of the $DK$ pair is resonating in isospin 0, forming the $D_{s0}^{\ast }(2317)$. The state can be interpreted as a $D{D}_{s0}^{\ast }(2317)$ molecule like state with exotic quantum numbers: doubly charged, doubly charmed, and with single strangeness.

   hep-phnucl-thPRD(2019)·42 citations
7. 07*

   Effects of neutrino mixing upon electron fraction in core collapse supernovae

   M.M. Saez🇦🇷 · M.E. Mosquera🇦🇷 · O. Civitarese🇦🇷

   The inclusion of massive neutrinos affects the cross sections involved in the formation of heavy nuclei, modifying their abundances. Rapid neutron capture processes (r-process) are often associated with explosive events such as core-collapse supernovae. In this work we study the effects of active and sterile neutrino oscillations and interactions, upon the calculation of neutrino fluxes, the baryonic density and the electron fraction of the material. We have considered two different initial distribution functions of the neutrinos and different combinations of mixing parameters (including {\theta} 34 = 0). We use the formalism of density matrices for the calculations and included the effects of neutrino oscillations, interactions with matter and self-neutrino interactions. We found that the interactions of the neutrinos with matter and with themselves change the electron fraction, affecting the onset of the r-process.

   hep-phastro-ph.SRnucl-thphysics.space-phBol.A.A.Astron.(2018)·0 citations
8. 08*

   The shadow of dark matter as a shadow of string theory

   Andrii Dashko🇨🇦 · Rainer Dick🇨🇦

   We point out that string theory can solve the conundrum to explain the emergence of an electroweak dipole moment from electroweak singlets through induction of those dipole moments through a Kalb-Ramond dipole coupling. This can generate a U_Y(1) portal to dark matter and entails the possibility that the U_Y(1) gauge field is related to a fundamental vector field for open string interactions. The requirement to explain the observed dark matter abundance relates the coupling scale in the corresponding low-energy effective U_Y(1) portal to the dark matter mass. The corresponding electron recoil cross sections for a single dipole coupled dark matter species are generically below the current limits from XENON, SuperCDMS and SENSEI, except in the GeV mass range if the electric dipole coupling becomes stronger than the magnetic coupling. Furthermore, the recoil cross sections are above the neutrino floor and the U_Y(1) portal can be tested with longer exposure or larger detectors. Discovery of electroweak dipole dark matter would therefore open an interesting window into string phenomenology.

   hep-phhep-thEPJC(2019)·12 citations
9. 09*

   $R_{D^{(\ast )}}$ in custodial warped space

   Marcela Carena🇺🇸 · Eugenio Megias🇪🇸 · Mariano Quiros🇪🇸 · Carlos Wagner🇺🇸

   Flavor physics experiments allow to probe the accuracy of the Standard Model (SM) description at low energies, and are sensitive to new heavy gauge bosons that couple to quarks and leptons in a relevant way. The apparent anomaly in the ratios of the decay of $B$-mesons into $D$-mesons and different lepton flavors, $R_{D^{(\ast )}}=\mathcal{B}(B\to D^{(\ast )}\tau \nu )/\mathcal{B}(B\to D^{(\ast )}\ell \nu )$ is particularly intriguing, since these decay processes occur at tree-level in the SM. Recently, it has been suggested that this anomaly may be explained by new gauge bosons coupled to right-handed currents of quarks and leptons, involving light right-handed neutrinos. In this work we present a well-motivated ultraviolet complete realization of this idea, embedding the SM in a warped space with an $SU(2{)}_L\otimes SU(2{)}_R\otimes U(1{)}_{B-L}$ bulk gauge symmetry. Besides providing a solution to the hierarchy problem, we show that this model, which has an explicit custodial symmetry, can explain the $R_{D^{(\ast )}}$ anomaly and at the same time allow for a solution to the $R_{K^{(\ast )}}$ anomalies, related to the decay of $B$-mesons into $K$-mesons and leptons, $R_{K^{(\ast )}}=\mathcal{B}(B\to K^{(\ast )}\mu \mu )/\mathcal{B}(B\to K^{(\ast )}ee)$. In addition, a model prediction is an anomalous value of the forward-backward asymmetry $A_{FB}^b$, driven by the $Z{\bar{b}}_R{b}_R$ coupling, in agreement with LEP data.

   hep-phhep-exJHEP(2018)·25 citations
10. 10*

    Neutrinophilic Axion-Like Dark Matter

    Guo-yuan Huang🇨🇳 · Newton Nath🇨🇳

    The axion-like particles (ALPs) are very good candidates of the cosmological dark matter, which can exist in many extensions of the standard model (SM). The mass range of the ALPs as the dark matter can extend from a sub-eV scale to almost $10^{-22}\mathrm{eV}$. On the other hand, the neutrinos are found to be massive and the SM must be extended to explain the sub-eV neutrino masses. It becomes very interesting to consider an exclusive coupling between these two low scale frontiers that are both beyond the SM. The propagation of neutrinos inside the Milky Way would undergo the coherent forward scattering effect with the ALP background, and the neutrino oscillation behavior can be modified by the ALP-induced potential. Assuming a derivative coupling between the ALP and the three generations of active neutrinos, possible impacts on the neutrino oscillation experiments have been explored in this paper. In particular, we have numerically studied the sensitivity of the Deep Underground Neutrino Experiment (DUNE). The astrophysical consequences of such coupling have also been investigated systematically.

    hep-phEPJC(2018)·66 citations
11. 11*

    An operational definition of quark and gluon jets

    Patrick T. Komiske🇺🇸 · Eric M. Metodiev🇺🇸 · Jesse Thaler🇺🇸

    While "quark" and "gluon" jets are often treated as separate, well-defined objects in both theoretical and experimental contexts, no precise, practical, and hadron-level definition of jet flavor presently exists. To remedy this issue, we develop and advocate for a data-driven, operational definition of quark and gluon jets that is readily applicable at colliders. Rather than specifying a per-jet flavor label, we aggregately define quark and gluon jets at the distribution level in terms of measured hadronic cross sections. Intuitively, quark and gluon jets emerge as the two maximally separable categories within two jet samples in data. Benefiting from recent work on data-driven classifiers and topic modeling for jets, we show that the practical tools needed to implement our definition already exist for experimental applications. As an informative example, we demonstrate the power of our operational definition using Z+jet and dijet samples, illustrating that pure quark and gluon distributions and fractions can be successfully extracted in a fully well-defined manner.

    hep-phhep-exJHEP(2018)·83 citations
12. 12*

    Collider probes of singlet fermionic dark matter scenarios for the Fermi gamma-ray excess

    Yeong Gyun Kim🇰🇷 · Chan Beom Park🇰🇷 · Seodong Shin🇺🇸

    We investigate the collider signatures of the three benchmark points in the singlet fermionic dark matter model. The benchmark points, which were introduced previously to explain the Fermi gamma-ray excess by dark matter (DM) pair annihilation at the Galactic center, have definite predictions for future collider experiments such as the International Linear Collider and the High-Luminosity LHC. We consider four collider observables: (1) Higgs signal strength (essentially $hZZ$ coupling), (2) triple Higgs coupling, (3) exotic Higgs decay, and (4) direct production of a new scalar particle. The benchmark points are classified by the final states of the DM annihilation process: a pair of $b$ quarks, SM-like Higgs bosons, and new scalar particles. Each benchmark scenario has detectable new physics signals for the above collider observables that can be well tested in the future lepton and hadron colliders.

    hep-phJHEP(2018)·9 citations
13. 13*

    Constraining Dissipative Dark Matter Self-Interactions

    Rouven Essig🇺🇸 · Samuel D. McDermott🇺🇸 · Hai-Bo Yu🇺🇸 · Yi-Ming Zhong🇺🇸

    We study the gravothermal evolution of dark matter halos in the presence of dissipative dark matter self-interactions. Dissipative interactions are present in many particle-physics realizations of the dark-sector paradigm and can significantly accelerate the gravothermal collapse of halos compared to purely elastic dark matter self-interactions. This is the case even when the dissipative interaction timescale is longer than the free-fall time of the halo. Using a semianalytical fluid model calibrated with isolated and cosmological $N$-body simulations, we calculate the evolution of the halo properties -- including its density profile and velocity dispersion profile -- as well as the core-collapse time as a function of the particle model parameters that describe the interactions. A key property is that the inner density profile at late times becomes cuspy again. Using 18 dwarf galaxies that exhibit a corelike dark matter density profile, we derive constraints on the strength of the dissipative interactions and the energy loss per collision.

    hep-phastro-ph.COastro-ph.GAPRL(2019)·174 citations
14. 14*

    Precise determination of the branching ratio of the neutral-pion Dalitz decay

    Tomáš Husek🇪🇸 · Evgueni Goudzovski🇬🇧 · Karol Kampf🇨🇿

    We provide a new value for the ratio $R=\Gamma ({\pi }^0\to e^{+}{e}^{-}\gamma (\gamma ))/\Gamma ({\pi }^0\to \gamma \gamma )=11.978(6)\times 10^{-3}$, which is by two orders of magnitude more precise than the current Particle Data Group average. It is obtained using the complete set of the next-to-leading-order radiative corrections in the QED sector, and incorporates up-to-date values of the ${\pi }^0$-transition-form-factor slope. The ratio $R$ translates into the branching ratios of the two main ${\pi }^0$ decay modes: $\mathcal{B}({\pi }^0\to \gamma \gamma )=98.8131(6)\%$ and $\mathcal{B}({\pi }^0\to e^{+}{e}^{-}\gamma (\gamma ))=1.1836(6)\%$.

    hep-phhep-exPRL(2019)·14 citations
15. 15*

    Third Family Hypercharge Model for $R_{K^{(\ast )}}$ and Aspects of the Fermion Mass Problem

    B.C. Allanach🇬🇧 · Joe Davighi🇬🇧

    We present a model to explain LHCb's recent measurements of $R_K$ and $R_{K^{\ast }}$ based on an anomaly-free, spontaneously-broken $U(1{)}_F$ gauge symmetry, without any fermionic fields beyond those of the Standard Model (SM). The model explains the hierarchical heaviness of the third family and the smallness of quark mixing. The $U(1{)}_F$ charges of the third family of SM fields and the Higgs doublet are set equal to their respective hypercharges. A heavy $Z^{\prime }$ particle with flavour-dependent couplings can modify the $[\overline{b_L}{\gamma }^{\rho }{s}_L][\overline{{\mu }_L}{\gamma }_{\rho }{\mu }_L]$ effective vertex in the desired way. The $Z^{\prime }$ contribution to $B_s-\overline{B_s}$ mixing is suppressed by a small mixing angle connected to $V_{ts}$, making the constraint coming from its measurement easier to satisfy. The model can explain $R_K$ and $R_{K^{(\ast )}}$ whilst simultaneously passing other constraints, including measurements of the lepton flavour universality of $Z$ couplings.

    hep-phhep-exJHEP(2018)·82 citations
16. 16*

    Hadronic tau decays as New Physics probes in the LHC era

    Vincenzo Cirigliano🇺🇸 · Adam Falkowski🇫🇷 · Martín González-Alonso🇨🇭 · Antonio Rodríguez-Sánchez🇪🇸

    We analyze the sensitivity of hadronic tau decays to non-standard interactions within the model-independent framework of the Standard Model Effective Field Theory (SMEFT). Both exclusive and inclusive decays are studied, using the latest lattice data and QCD dispersion relations. We show that there are enough theoretically clean channels to disentangle all the effective couplings contributing to these decays, with the $\tau \to \pi \pi {\nu }_{\tau }$ channel representing an unexpected powerful New Physics probe. We find that the ratios of non-standard couplings to the Fermi constant are bound at the sub-percent level. These bounds are complementary to the ones from electroweak precision observables and $pp\to \tau {\nu }_{\tau }$ measurements at the LHC. The combination of tau decay and LHC data puts tighter constraints on lepton universality violation in the gauge boson-lepton vertex corrections.

    hep-phPRL(2019)·90 citations
17. 17*

    $SO(32)$ heterotic standard model vacua in general Calabi-Yau compactifications

    Hajime Otsuka🇯🇵 · Kenta Takemoto🇯🇵

    We study a direct flux breaking scenario in $SO(32)$ heterotic string theory on general Calabi-Yau threefolds. The direct flux breaking, corresponding to hypercharge flux breaking in the F-theory context, allows us to derive the Standard Model in general Calabi-Yau compactifications. We present a general formula leading to the three generations of quarks and leptons and no chiral exotics in a background-independent way. As a concrete example, we show the three-generation model on a complete intersection Calabi-Yau threefold.

    ↳ hep-thhep-phJHEP(2018)·8 citations
18. 18*

    Some aspects of non-perturbative QCD from non-susy D3 brane of Type IIB string theory

    Kuntal Nayek🇮🇳 · Shibaji Roy🇮🇳

    It is well-known that the non-supersymmetric D3 brane (a cousin of BPS D3 brane) including its black version of type IIB string theory has a decoupling limit, where the decoupled geometry is the gravity dual of a non-supersymmetric, non-conformal (finite temperature) quantum field theory having some properties similar to QCD. Using the ideas of AdS/CFT we study some non-perturbative aspects of this quantum field theory. Since in this case we have a Yang-Mills theory (no quarks) with running coupling (non-constant dilaton), we compute the gluon condensate in this theory as a function of temperature and also compute the beta function. The behavior of the gluon condensate is found to resemble much like the SU(3) lattice QCD result and the beta function is found to be negative. We further compute both the pseudoscalar and the scalar glueball mass spectra in this theory using WKB approximation and find that the mass ratios of the first excited state to the ground state of the scalar glueball are quite close to the lattice QCD results.

    ↳ hep-thhep-lathep-ph1 citation
19. 19*

    Baryonic handles: Skyrmions as open vortex strings on a domain wall

    Sven Bjarke Gudnason🇯🇵 · Muneto Nitta🇯🇵

    We consider the BEC-Skyrme model which is based on a Skyrme-type model with a potential motivated by Bose-Einstein condensates (BECs) and, in particular, we study the Skyrmions in proximity of a domain wall that inhabits the theory. The theory turns out to have a rich flora of Skyrmion solutions that manifest themselves as twisted vortex rings or vortons in the bulk and vortex handles attached to the domain wall. The latter are linked open vortex strings. We further study the interaction between the domain wall and the Skyrmion and between the vortex handles themselves as well as between the vortex handle and the vortex ring in the bulk. We find that the domain wall provides a large binding energy for the solitons and it is energetically preferred to stay as close to the domain wall as possible; other configurations sticking into the bulk are metastable. We find that the most stable 2-Skyrmion is a torus-shaped braided string junction ending on the domain wall, which is produced by a collision of two vortex handles on the wall, but there is also a metastable configuration which is a doubly twisted vortex handle produced by a collision of a vortex handle on the wall and a vortex ring from the bulk.

    ↳ hep-thhep-phPRD(2018)·8 citations
20. 20*

    Identifying a first-order phase transition in neutron star mergers through gravitational waves

    Andreas Bauswein🇩🇪 · Niels-Uwe F. Bastian🇵🇱 · David B. Blaschke🇵🇱 · Katerina Chatziioannou🇨🇦 · James A. Clark🇺🇸 · Tobias Fischer🇵🇱 · Micaela Oertel🇫🇷

    We identify an observable imprint of a first-order hadron-quark phase transition at supranuclear densities on the gravitational-wave (GW) emission of neutron star mergers. Specifically, we show that the dominant postmerger GW frequency f_peak may exhibit a significant deviation from an empirical relation between f_peak and the tidal deformability if a strong first-order phase transition leads to the formation of a gravitationally stable extended quark matter core in the postmerger remnant. A comparison of the GW signatures from a large, representative sample of microphysical, purely hadronic equations of state indicates that this imprint is only observed in those systems which undergo a strong first-order phase transition. Such a shift of the dominant postmerger GW frequency can be revealed by future GW observations, which would provide evidence for the existence of a strong first-order phase transition in the interior of neutron stars.

    ↳ astro-ph.HEhep-phnucl-thPRL(2019)·471 citations
21. 21*

    Bounds on Ultra-Light Hidden-Photon Dark Matter from 21cm at Cosmic Dawn

    Ely D. Kovetz🇺🇸 · Ilias Cholis🇺🇸 · David E. Kaplan🇺🇸

    Ultra-light hidden-photon dark matter produces an oscillating electric field in the early Universe plasma, which in turn induces an electric current in its ionized component whose dissipation results in heat transfer from the dark matter to the plasma. This will affect the global 21cm signal from the Dark Ages and Cosmic Dawn. In this work we focus on the latter, in light of the reported detection by the EDGES collaboration of an absorption signal at frequencies corresponding to redshift z~17. By measuring the 21cm global signal, a limit can be placed on the amount of gas heating, and thus the kinetic mixing strength $\epsilon$ between the hidden and ordinary photons can be constrained. Our inferred 21cm bounds on $\epsilon$ in the mass range $10^{-23}\mathrm{eV}\lesssim m_{\chi }\lesssim 10^{-13}\mathrm{eV}$ are the strongest to date.

    ↳ astro-ph.COhep-phPRD(2019)·40 citations
22. 22*

    Reheating and Dark Radiation after Fibre Inflation

    Michele Cicoli🇮🇹 · Gabriel A. Piovano🇮🇹

    We study perturbative reheating at the end of fibre inflation where the inflaton is a closed string modulus with a Starobinsky-like potential. We first derive the spectral index $n_s$ and the tensor-to-scalar ratio $r$ as a function of the number of efoldings and the parameter $R$ which controls slow-roll breaking corrections. We then compute the inflaton couplings and decay rates into ultra-light bulk axions and visible sector fields on D7-branes wrapping the inflaton divisor. This leads to a reheating temperature of order $10^{10}$ GeV which requires $52$ efoldings. Ultra-light axions contribute to dark radiation even if $\Delta N_{\mathrm{eff}}$ is almost negligible in the generic case where the visible sector D7-stack supports a non-zero gauge flux. If the parameter $R$ is chosen to be small enough, $n_s\simeq 0.965$ is then in perfect agreement with current observations while $r$ turns out to be of order $r\simeq 0.007$. If instead the flux on the inflaton divisor is turned off, $\Delta N_{\mathrm{eff}}\lesssim 0.6$ which, when used as a prior for Planck data, requires $n_s\simeq 0.99$. After $R$ is fixed to obtain such a value of $n_s$, primordial gravity waves are larger since $r\simeq 0.01$.

    ↳ hep-thastro-ph.COhep-phJCAP(2019)·42 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.