Thu·Aug 18, 2016Thursday·August 18, 2016

1. 01*

   Sizable NSI from the $SU(2{)}_L$ scalar doublet-singlet mixing and the implications in DUNE

   David V. Forero🇺🇸 · Wei-Chih Huang🇩🇪

   We propose a novel and simple mechanism where sizable effects of non-standard interactions (NSI) in neutrino propagation are induced from the mixing between an electrophilic second Higgs doublet and a charged singlet. The mixing arises from a dimensionful coupling of the scalar doublet and singlet to the standard model Higgs boson. In light of the small mass, the light mass eigenstate from the doublet-singlet mixing can generate much larger NSI than those induced by the heavy eigenstate. We show that a sizable NSI ${\epsilon }_{e\tau }$ ($\sim 0.3$) can be attained without being excluded by a variety of experimental constraints. Furthermore, we demonstrate that NSI can mimic effects of the Dirac CP phase in the neutrino mixing matrix but they can potentially be disentangled by future long-baseline neutrino experiments, such as the Deep Underground Neutrino Experiment (DUNE).

   hep-phhep-exJHEP(2017)·46 citations
2. 02*

   Secretly Asymmetric Dark Matter

   Prateek Agrawal🇺🇸 · Can Kilic🇺🇸 · Sivaramakrishnan Swaminathan🇺🇸 · Cynthia Trendafilova🇺🇸

   We study a mechanism where the dark matter number density today arises from asymmetries generated in the dark sector in the early universe, even though total dark matter number remains zero throughout the history of the universe. The dark matter population today can be completely symmetric, with annihilation rates above those expected from thermal WIMPs. We give a simple example of this mechanism using a benchmark model of flavored dark matter. We discuss the experimental signatures of this setup, which arise mainly from the sector that annihilates the symmetric component of dark matter.

   hep-phPRD(2017)·15 citations
3. 03*

   R-Parity violation in F-Theory

   Miguel Crispim Romão🇬🇧 · Athanasios Karozas🇬🇷 · Stephen F. King🇬🇧 · George K. Leontaris🇬🇷 · Andrew K. Meadowcroft🇬🇧

   We discuss R-parity violation (RPV) in semi-local and local F-theory constructions. We first present a detailed analysis of all possible combinations of RPV operators arising from semi-local F-theory spectral cover constructions, assuming an $SU(5)$ GUT. We provide a classification of all possible allowed combinations of RPV operators originating from operators of the form $10\cdot \bar{5}\cdot \bar{5}$, including the effect of $U(1)$ fluxes with global restrictions. We then relax the global constraints and perform explicit computations of the bottom/tau and RPV Yukawa couplings, at an $SO(12)$ local point of enhancement in the presence of general fluxes subject only to local flux restrictions. We compare our results to the experimental limits on each allowed RPV operator, and show that operators such as $LL{e}^c$, $LQ{d}^c$ and $u^c{d}^c{d}^c$ may be present separately within current bounds, possibly on the edge of observability, suggesting lepton number violation or neutron-antineutron oscillations could constrain F-theory models.

   hep-phJHEP(2016)·12 citations
4. 04*

   Scrutinizing a di-photon resonance at the LHC through Moscow zero

   Giorgio Arcadi🇫🇷 · Pradipta Ghosh🇫🇷 · Yann Mambrini🇫🇷 · Mathias Pierre🇫🇷

   The ATLAS and CMS collaborations have recently released their new analyses of the diphoton searches. We look in detail the consequences of their results deriving strong constraints on models where a scalar resonance $s$ decays into two light pseudoscalars which in turn decay into two pairs of collimated photons, mis-identified with two real photons. In our construction, all mass terms are generated dynamically, and only one pair of vector-like fermions generate couplings which will be probed using the upcoming LHC data. Moreover, we show that a stable dark matter candidate, respecting the cosmological constraints, is naturally affordable in the model.

   hep-phhep-exJCAP(2016)·5 citations
5. 05*

   Revealing the source of the radial flow patterns in proton--proton collisions using hard probes

   Antonio Ortiz🇲🇽 · Gyula Bencédi🇲🇽 · Héctor Bello🇲🇽

   In this work, we propose a tool to reveal the origin of the collective-like phenomena observed in proton--proton collisions. We exploit the fundamental difference between the underlying mechanisms, color reconnection (CR) and hydrodynamics, which produce radial flow patterns in \textsc{Pythia}~8 and \textsc{Epos}~3, respectively. Specifically, we proceed by examining the strength of the coupling between the soft and hard components which, by construction, is larger in \textsc{Pythia}~8 than in \textsc{Epos}~3. We study the transverse momentum ($p_{\mathrm{T}}$) distributions of charged pions, kaons and (anti)protons in inelastic pp collisions at $\sqrt{s}=$ 7\,TeV produced at mid-rapidity. Specific selections are made on an event-by-event basis as a function of the charged particle multiplicity and the transverse momentum of the leading jet ($p_{\mathrm{T}}^{\mathrm{jet}}$) reconstructed using the \textsc{FastJet} algorithm at mid-pseudorapidity ($|\eta |<1$). From our studies, quantitative and qualitative differences between \textsc{Pythia}~8 and \textsc{Epos}~3 are found in the $p_{\mathrm{T}}$ spectra when (for a given multiplicity class) the leading jet $p_{\mathrm{T}}$ is increased. In addition, we show that for low-multiplicity events the presence of jets can produce radial flow-like behavior. Motivated by our findings, we propose to perform a similar analysis using experimental data from RHIC and LHC.

   hep-phnucl-thJ.Phys.G(2017)·54 citations
6. 06*

   Resonance $X(5568)$ as an exotic axial-vector state

   S. S. Agaev🇦🇿 · K. Azizi🇹🇷 · B. Barsbay🇹🇷 · H. Sundu🇹🇷

   The mass and meson-current coupling constant of the resonance $X(5568)$, as well as the width of the decay $X(5568)\to B_s^{\ast }\pi$ are calculated by modeling the exotic $X(5568)$ resonance as a diquark-antidiquark state with quantum numbers $J^P=1^{+}$. The calculations are made employing QCD two-point sum rule method, where the quark, gluon and mixed vacuum condensates up to dimension eight are taken into account. The sum rule approach on the light-cone in its soft-meson approximation is used to explore the vertex $X_b{B}_s^{\ast }\pi$ and extract the strong coupling , which is a necessary ingredient to find the width of the $X_b\to B_s^{\ast }{\pi }^{+}$ decay process. The obtained predictions are compared with the experimental data of the D0 Collaboration, and results of other theoretical works.

   hep-phEPJA(2017)·15 citations
7. 07*

   Full top quark mass dependence in Higgs boson pair production at NLO

   S.Borowka🇨🇭 · N.Greiner🇨🇭 · G.Heinrich🇩🇪 · S.P.Jones🇩🇪 · M.Kerner🇩🇪 · J.Schlenk🇩🇪 · T.Zirke🇩🇪

   We study the effects of the exact top-quark mass dependent two-loop corrections to Higgs boson pair production by gluon fusion at the LHC and at a 100 TeV hadron collider. We perform a detailed comparison of the full next-to-leading order result to various approximations at the level of differential distributions and also analyse non-standard Higgs self-coupling scenarios. We find that the different next-to-leading order approximations differ from the full result by up to 50 percent in relevant differential distributions. This clearly stresses the importance of the full NLO result.

   hep-phJHEP(2016)·284 citations
8. 08*

   Consequences of R-Parity violating interactions for anomalies in $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$ and $b\to s{\mu }^{+}{\mu }^{-}$

   N. G. Deshpande🇺🇸 · Xiao-Gang He🇨🇳

   We investigate the possibility of explaining the enhancement in semileptonic decays of $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$, the anomalies induced by $b\to s{\mu }^{+}{\mu }^{-}$ in $\bar{B}\to (K,K^{\ast },\varphi ){\mu }^{+}{\mu }^{-}$ and violation of lepton universality in $R_K=Br(\bar{B}\to K{\mu }^{+}{\mu }^{-})/Br(\bar{B}\to K{e}^{+}{e}^{-})$ within the framework of R-parity violating (RPV) MSSM. Exchange of down type right-handed squark coupled to quarks and leptons yield interactions which are similar to leptoquark induced interactions that have been proposed to explain the $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$ by tree level interactions and $b\to s{\mu }^{+}{\mu }^{-}$ anomalies by loop induced interactions, simultaneously. However, the Yukawa couplings in such theories have severe constraints from other rare processes in $B$ and $D$ decays. Although this interaction can provide a viable solution to $R(D^{(\ast )})$ anomaly, we show that with the severe constraint from $\bar{B}\to K\nu \bar{\nu }$, it is impossible to solve the anomalies in $b\to s{\mu }^{+}{\mu }^{-}$ process simultaneously.

   hep-phhep-exEPJC(2017)·100 citations
9. 09*

   Nature of charmed strange baryons ${\Xi }_c(3055)$ and ${\Xi }_c(3080)$

   Ze Zhao🇨🇳 · Dan-Dan Ye🇨🇳 · Ailin Zhang🇨🇳

   The hadronic decay widths and some ratios of branching fractions of the newly observed charmed strange baryons, ${\Xi }_c(3055{)}^0$, ${\Xi }_c(3055{)}^{+}$ and ${\Xi }_c(3080{)}^{+}$ are calculated in a ${}^3{P}_0$ model. In the calculation, they are considered as $34$ kinds of $D-wave$ charmed strange baryons. Among these assignments, ${\Xi }_c(3055{)}^{+}$ is very possibly a $J^P={\frac{5}{2}}^{+}$ ${\hat{\Xi }}_{c3}^{\prime }({\frac{5}{2}}^{+})$ or ${\check{\Xi }}_{c3}^2({\frac{5}{2}}^{+})$, where ${\Xi }_c(3055{)}^{+}$ has the total decay width $\Gamma =10.1$ MeV and $\Gamma =7.6$ MeV. The predicted ratios $\Gamma ({\Xi }_c(3055{)}^{+}\to \Lambda D^{+})/\Gamma ({\Xi }_c(3055{)}^{+}\to {\Sigma }_c^{++}{K}^{-})=3.39$. ${\Xi }_c(3055{)}^{+}$ is also very possibly a $J^P={\frac{7}{2}}^{+}$ ${\hat{\Xi }}_{c3}^{\prime }({\frac{7}{2}}^{+})$ or ${\check{\Xi }}_{c3}^2({\frac{7}{2}}^{+})$. In these two assignments, ${\Xi }_c(3055{)}^{+}$ has the total decay width $\Gamma =9.7$ MeV and $\Gamma =6.3$ MeV. The predicted ratios $\Gamma ({\Xi }_c(3055{)}^{+}\to \Lambda D^{+})/\Gamma ({\Xi }_c(3055{)}^{+}\to {\Sigma }_c^{++}{K}^{-})=5.91\mathrm{or}6.04$. As a isospin partner of ${\Xi }_c(3055{)}^{+}$, ${\Xi }_c(3055{)}^0$ is also very possibly a $J^P={\frac{5}{2}}^{+}$ ${\hat{\Xi }}_{c3}^{\prime }({\frac{5}{2}}^{+})$ or ${\check{\Xi }}_{c3}^2({\frac{5}{2}}^{+})$, where ${\Xi }_c(3055{)}^0$ has the total decay width $\Gamma =10.9$ MeV and $\Gamma =7.0$ MeV. The predicted ratios $\Gamma ({\Xi }_c(3055{)}^0\to \Lambda D^0)/\Gamma ({\Xi }_c(3055{)}^0\to {\Sigma }_c^{+}{K}^{-})=4.24\mathrm{or}4.20$. ${\Xi }_c(3055{)}^0$ is also very possibly a $J^P={\frac{7}{2}}^{+}$ ${\hat{\Xi }}_{c3}^{\prime }({\frac{7}{2}}^{+})$ or ${\check{\Xi }}_{c3}^2({\frac{7}{2}}^{+})$. In these assignments, ${\Xi }_c(3055{)}^0$ has the total decay width $\Gamma =10.3$ MeV and $\Gamma =7.1$ MeV. The predicted ratios $\Gamma ({\Xi }_c(3055{)}^0\to \Lambda D^0)/\Gamma ({\Xi }_c(3055{)}^0\to {\Sigma }_c^{+}{K}^{-})=7.47\mathrm{or}7.56$. The results agree well with recent experimental data from Belle. ${\Xi }_c(3080{)}^{+}$ seems impossible to be identified with a D-wave charmed strange baryon.

   hep-phhep-exPRD(2016)·29 citations
10. 10*

    Leptogenesis after Chaotic Sneutrino Inflation and the Supersymmetry Breaking Scale

    Fredrik Björkeroth🇬🇧 · Stephen F. King🇬🇧 · Kai Schmitz🇩🇪 · Tsutomu T. Yanagida🇯🇵

    We discuss resonant leptogenesis arising from the decays of two nearly-degenerate right-handed neutrinos, identified as the inflaton and stabiliser superfields in a model of chaotic sneutrino inflation. We compare an analytical estimate of the baryon asymmetry ${\eta }_B$ in the Boltzmann approximation to a numerical solution of the full density matrix equations, and find that the analytical result fails to capture the correct physics in certain regions of parameter space. The observed baryon asymmetry can be realised for a breaking of the mass degeneracy as small as $\mathcal{O}(10^{-8})$. The origin of such a small mass splitting is explained by considering supersymmetry (SUSY) breaking in supergravity, which requires a constant in the superpotential of the order of the gravitino mass $m_{3/2}$ to cancel the cosmological constant. This yields additional terms in the (s)neutrino mass matrices, lifting the degeneracy and linking ${\eta }_B$ to the SUSY breaking scale. We find that achieving the correct baryon asymmetry requires a gravitino mass $m_{3/2}\ge \mathcal{O}(100)$ TeV.

    hep-phNPB(2017)·15 citations
11. 11*

    Higgs Vacuum Stability and Modified Chaotic Inflation

    Abhijit Kumar Saha🇮🇳 · Arunansu Sil🇮🇳

    The issue of electroweak vacuum stability is studied in presence of a scalar field which participates in modifying the minimal chaotic inflation model. It is shown that the threshold effect on the Higgs quartic coupling originating from the Higgs-inflaton sector interaction can essentially make the electroweak vacuum stable upto the Planck scale. On the other hand we observe that the new physics parameters in this combined framework are enough to provide deviation from the minimal chaotic inflation predictions so as to keep it consistent with recent observation by Planck 2015.

    hep-phhep-thPLB(2017)·18 citations
12. 12*

    Soft factors for double parton scattering at NNLO

    Alexey Vladimirov🇩🇪

    We show at NNLO that the soft factors for double parton scattering (DPS) for both integrated and unintegrated kinematics, can be presented entirely in the terms of the soft factor for single Drell-Yan process, i.e. the transverse momentum dependent (TMD) soft factor. Using the linearity of the logarithm of TMD soft factor in rapidity divergences, we decompose the DPS soft factor matrices into a product of matrices with rapidity divergences in given sectors, and thus, define individual double parton distributions at NNLO. The rapidity anomalous dimension matrices for double parton distributions are presented in the terms of TMD rapidity anomalous dimension. The analysis is done using the generating function approach to web diagrams. Significant part of the result is obtained from the symmetry properties of web diagrams without referring to explicit expressions or a particular rapidity regularization scheme. Additionally, we present NNLO expression for the web diagram generating function for Wilson lines with two light-like directions.

    hep-phJHEP(2016)·24 citations
13. 13*

    Determination of ${\Lambda }_{\overline{MS}}$ at five loops from holographic QCD

    A. Deur🇺🇸 · S. J. Brodsky🇺🇸 · G. F. de Teramond🇨🇷

    The recent determination of the $\beta$--function of the QCD running coupling ${\alpha }_{\overline{MS}}(Q^2)$ to 5-loops{\color{blue},} provides a verification of the convergence of a novel method for determining the fundamental QCD parameter ${\Lambda }_s$ based on the Light-Front Holographic approach to nonperturbative QCD. The new 5-loop analysis, together with improvements in determining the holographic QCD nonperturbative scale parameter $\kappa$ from hadronic spectroscopy, leads to an improved precision of the value of ${\Lambda }_s$ in the $\overline{MS}$ scheme close to a factor of two; we find ${\Lambda }_{\overline{MS}}^{(3)}=0.339\pm 0.019$ GeV for $n_f=3$, in excellent agreement with the world average, ${\Lambda }_{\overline{MS}}^{(3)}=0.332\pm 0.017$ GeV. We also discuss the constraints imposed on the scale dependence of the strong coupling in the nonperturbative domain by superconformal quantum mechanics and its holographic embedding in anti-de Sitter space.

    hep-phJ.Phys.G(2017)·43 citations
14. 14*

    Role of particle masses in the magnetic field generation driven by the parity violating interaction

    Maxim Dvornikov (IZMIRAN, Tomsk State University, University of Hamburg)🇷🇺

    Recently the new model for the generation of strong large scale magnetic fields in neutron stars, driven by the parity violating interaction, was proposed. In this model, the magnetic field instability results from the modification of the chiral magnetic effect in presence of the electroweak interaction between ultrarelativistic electrons and nucleons. In the present work we study how a nonzero mass of charged particles, which are degenerate relativistic electrons and nonrelativistic protons, influences the generation of the magnetic field in frames of this approach. For this purpose we calculate the induced electric current of these charged particles, electroweakly interacting with background neutrons and an external magnetic field, exactly accounting for the particle mass. This current is calculated by two methods: using the exact solution of the Dirac equation for a charged particle in external fields and computing the polarization operator of a photon in matter composed of background neutrons. We show that the induced current is vanishing in both approaches leading to the zero contribution of massive particles to the generated magnetic field. We discuss the implication of our results for the problem of the magnetic field generation in compact stars.

    hep-phastro-ph.HEhep-thPLB(2016)·20 citations
15. 15*

    Generation of strong magnetic fields in dense quark matter driven by the electroweak interaction of quarks

    Maxim Dvornikov (IZMIRAN, Tomsk State University, University of Hamburg)🇷🇺

    We study the generation of strong large scale magnetic fields in dense quark matter. The magnetic field growth is owing to the magnetic field instability driven by the electroweak interaction of quarks. We discuss the situation when the chiral symmetry is unbroken in the degenerate quark matter. In this case we predict the amplification of the seed magnetic field $10^{12}\text{G}$ to the strengths $(10^{14}-10^{15})\text{G}$. In our analysis we use the typical parameters of the quark matter in the core of a hybrid star or in a quark star. We also discuss the application of the obtained results to describe the magnetic fields generation in magnetars.

    hep-phastro-ph.HEhep-thnucl-thNPB(2016)·17 citations
16. 16*

    Relaxation of the chiral imbalance in dense matter of a neutron star

    Maxim Dvornikov (IZMIRAN, Tomsk State University, University of Hamburg)🇷🇺

    Using the quantum field theory methods, we calculate the helicity flip of an electron scattering off protons in dense matter of a neutron star. The influence of the electroweak interaction between electrons and background nucleons on the helicity flip is examined. We also derive the kinetic equation for the chiral imbalance. The derived kinetic equation is compared with the results obtained by other authors.

    hep-phastro-ph.HEnucl-thEPJ Web Conf.(2016)·0 citations
17. 17*

    Collinear limits beyond the leading order from the scattering equations

    Dhritiman Nandan🇩🇪 · Jan Plefka🇩🇪 · Wadim Wormsbecher🇩🇪

    The structure of tree-level scattering amplitudes for collinear massless bosons is studied beyond their leading splitting function behavior. These near-collinear limits at sub-leading order are best studied using the Cachazo-He-Yuan (CHY) formulation of the S-matrix based on the scattering equations. We compute the collinear limits for gluons, gravitons and scalars. It is shown that the CHY integrand for an n-particle gluon scattering amplitude in the collinear limit at sub-leading order is expressed as a convolution of an (n-1)-particle gluon integrand and a collinear kernel integrand, which is universal. Our representation is shown to obey recently proposed amplitude relations in which the collinear gluons of same helicity are replaced by a single graviton. Finally, we extend our analysis to effective field theories and study the collinear limit of the non-linear sigma model, Einstein-Maxwell-Scalar and Yang-Mills-Scalar theory.

    ↳ hep-thhep-phJHEP(2017)·34 citations
18. 18*

    Sound shell model for acoustic gravitational wave production at a first-order phase transition in the early Universe

    Mark Hindmarsh🇬🇧

    A model for the acoustic production of gravitational waves at a first order phase transition is presented. The source of gravitational radiation is the sound waves generated by the explosive growth of bubbles of the stable phase. The model assumes that the sound waves are linear and that their power spectrum is determined by the characteristic form of the sound shell around the expanding bubble. The predicted power spectrum has two length scales, the average bubble separation and the sound shell width when the bubbles collide. The peak of the power spectrum is at wavenumbers set by the sound shell width. For higher wavenumber $k$, the power spectrum decreases as $k^{-3}$. At wavenumbers below the inverse bubble separation, the power spectrum goes as $k^5$. For bubble wall speeds near the speed of sound where these two length scales are distinguished, there is an intermediate $k^1$ power law. The detailed dependence of the power spectrum on the wall speed and the other parameters of the phase transition raises the possibility of their constraint or measurement at a future space-based gravitational wave observatory such as eLISA.

    ↳ astro-ph.COhep-phPRL(2018)·264 citations
19. 19*

    Leading-twist distribution amplitudes of scalar- and vector-mesons

    Bo-Lin Li🇨🇳 · Lei Chang🇨🇳 · Minghui Ding🇨🇳 · Craig D. Roberts🇺🇸 · Hong-Shi Zong🇨🇳

    A symmetry-preserving truncation of the two-body light-quark bound-state problem in relativistic quantum field theory is used to calculate the leading-twist parton distribution amplitudes (PDAs) of scalar systems, both ground-state and radial excitations, and the radial excitations of vector mesons. Owing to the fact that the scale-independent leptonic decay constant of a scalar meson constituted from equal-mass valence-constituents vanishes, it is found that the PDA of a given scalar system possesses one more zero than that of an analogous vector meson. Consequently, whereas the mean light-front relative momentum of the valence-constituents within a vector meson is zero, that within a scalar meson is large, an outcome which hints at a greater role for light-front angular momentum in systems classified as $P$-wave in quantum mechanical models. Values for the scale-dependent decay constants of ground-state scalar and vector systems are a by-product of this analysis, and they turn out to be roughly equal, viz. $\simeq 0.2$GeV at an hadronic scale. In addition, it is confirmed that the dilation characterising ground-state PDAs is manifest in the PDAs of radial excitations too. The impact of $SU(3)$-flavour symmetry breaking is also considered. When compared with pseudoscalar states, it is a little stronger in scalar systems, but the size is nevertheless determined by the flavour-dependence of dynamical chiral symmetry breaking and the PDAs are still skewed toward the heavier valence-quark in asymmetric systems.

    ↳ nucl-thhep-lathep-phnucl-exPRD(2016)·27 citations
20. 20*

    Neutrinoless double beta decay from lattice QCD

    Amy Nicholson🇺🇸 · Evan Berkowitz🇺🇸 · Chia Cheng Chang🇺🇸 · M. A. Clark🇺🇸 · Balint Joo🇺🇸 · Thorsten Kurth🇺🇸 · Enrico Rinaldi🇺🇸 · Brian Tiburzi🇺🇸 · Pavlos Vranas🇺🇸 · Andre Walker-Loud🇺🇸

    While the discovery of non-zero neutrino masses is one of the most important accomplishments by physicists in the past century, it is still unknown how and in what form these masses arise. Lepton number-violating neutrinoless double beta decay is a natural consequence of Majorana neutrinos and many BSM theories, and many experimental efforts are involved in the search for these processes. Understanding how neutrinoless double beta decay would manifest in nuclear environments is key for understanding any observed signals. In these proceedings we present an overview of a set of one- and two-body matrix elements relevant for experimental searches for neutrinoless double beta decay, describe the role of lattice QCD calculations, and present preliminary lattice QCD results.

    ↳ hep-lathep-phnucl-thPoS(2016)·25 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.