Thu·Jul 16, 2015Thursday·July 16, 2015

1. 01*

   Spin-1 resonances in a non-linear left-right dynamical Higgs context

   Juan Yepes🇨🇳

   All the possible CP-conserving non-linear operators up to the $p^4$-order in the Lagrangian expansion are clearly and completely listed for the case of an emerging new physics field content in the nature, more specifically, from spin-1 resonances sourced by the straightforward extension of the SM local gauge symmetry to the larger local group $SU(2{)}_L\otimes SU(2{)}_R\otimes U(1{)}_{B-L}$, within a non-linear electroweak chiral context coupled to a light dynamical Higgs. The physical effects induced by integrating out the right handed fields from the physical spectrum are briefly analysed. The relevant set of effective operators have been identified at low energies.

   hep-phPoS(2016)·11 citations
2. 02*

   A Sterile Neutrino at DUNE

   Jeffrey M. Berryman🇺🇸 · Andre de Gouvea🇺🇸 · Kevin J. Kelly🇺🇸 · Andrew Kobach🇺🇸

   We investigate the potential for the Deep Underground Neutrino Experiment (DUNE) to probe the existence and effects of a fourth neutrino mass-eigenstate. We study the mixing of the fourth mass-eigenstate with the three active neutrinos of the Standard Model, including the effects of new sources of CP-invariance violation, for a wide range of new mass-squared differences, from lower than 10^-5 eV^2 to higher than 1 eV^2. DUNE is sensitive to previously unexplored regions of the mixing angle - mass-squared difference parameter space. If there is a fourth neutrino, in some regions of the parameter space, DUNE is able to measure the new oscillation parameters (some very precisely) and clearly identify two independent sources of CP-invariance violation. Finally, we use the hypothesis that there are four neutrino mass-eigenstates in order to ascertain how well DUNE can test the limits of the three-massive-neutrinos paradigm. In this way, we briefly explore whether light sterile neutrinos can serve as proxies for other, in principle unknown, phenomena that might manifest themselves in long-baseline neutrino oscillation experiments.

   hep-phhep-exPRD(2015)·102 citations
3. 03*

   Enhancement of new physics signal sensitivity with mistagged charm quarks

   Doojin Kim🇺🇸 · Myeonghun Park🇰🇷

   We investigate the potential for enhancing search sensitivity for signals having charm quarks in the final state, using the sizable bottom-mistagging rate for charm quarks at the LHC. Provided that the relevant background processes contain light quarks instead of charm quarks, the application of b-tagging on charm quark-initiated jets enables us to reject more background events than signal ones due to the relatively small mistagging rate for light quarks. The basic idea is tested with two rare top decay processes: i) t -> c h -> c b bbar and ii) t -> b H+ -> b bbar c where h and H+ denote the Standard Model-like higgs boson and a charged higgs boson, respectively. The major background source is a hadronic top quark decay such as t -> b W+ -> b sbar c. We test our method with Monte Carlo simulation at the LHC 14TeV, and find that the signal-over-background ratio can be increased by a factor of O(6-7) with a suitably designed (heavy) flavor tagging algorithm and scheme.

   hep-phhep-exPLB(2016)·8 citations
4. 04*

   Sbottom discovery via mixed decays at the LHC

   Tao Han (Pittsburgh U. and Tsinghua U.)🇺🇸 · Shufang Su (Arizona U. and Tsinghua U.)🇺🇸 · Yongcheng Wu (Tsinghua U.)🇨🇳 · Bin Zhang (Tsinghua U.)🇨🇳 · Huanian Zhang (Arizona U.)🇺🇸

   In the search for bottom squark (sbottom) in SUSY at the LHC, the common practice has been to assume a $100\%$ decay branching fraction for a given search channel. In realistic MSSM scenarios, there are often more than one significant decay modes to be present, which significantly weaken the current sbottom search limits at the LHC. On the other hand, the combination of the multiple decay modes offers alternative discovery channels for sbottom searches. In this paper, we present the sbottom decays in a few representative mass parameter scenarios. We then analyze the sbottom signal for the pair production in QCD with one sbottom decaying via $\tilde{b}\to b{\chi }_1^0,b{\chi }_2^0$, and the other one decaying via $\tilde{b}\to t{\chi }_1^{\pm }$. With the gaugino subsequent decaying to gauge bosons or a Higgs boson ${\chi }_2^0\to Z{\chi }_1^0,h{\chi }_1^0$ and ${\chi }_1^{\pm }\to W^{\pm }{\chi }_1^0$, we study the reach of those signals at the 14 TeV LHC with 300 $\mathrm{f}{\mathrm{b}}^{-1}$ integrated luminosity. For a left-handed bottom squark, we find that a mass up to 920 GeV can be discovered at 5$\sigma$ significance for 250 GeV $<m_{{\chi }_1^0}<$ 350 GeV, or excluded up to 1050 GeV at the 95\% confidence level for the $h$ channel ($\mu >0$); similarly, it can be discovered up to 840 GeV, or excluded up to 900 GeV at the 95\% confidence level for the $Z$ channel ($\mu <0$). The sbottom and stop signals in the same SUSY parameter scenario are combined to obtain the optimal sensitivity, which is about 150 GeV better than the individual reach of the sbottom or stop. For a right-handed bottom squark with $\tilde{b}{\tilde{b}}^{\ast }\to b{\chi }_1^0,t{\chi }_1^{\pm }$ channel, we find that the sbottom mass up to 880 GeV can be discovered at 5$\sigma$ significance, or excluded up to 1060 GeV at the 95\% confidence level.

   hep-phPRD(2015)·6 citations
5. 05*

   Direct Detection Signatures of Self-Interacting Dark Matter with a Light Mediator

   Eugenio Del Nobile🇺🇸 · Manoj Kaplinghat🇺🇸 · Hai-Bo Yu🇺🇸

   Self-interacting dark matter (SIDM) is a simple and well-motivated scenario that could explain long-standing puzzles in structure formation on small scales. If the required self-interaction arises through a light mediator (with mass $\sim 10$ MeV) in the dark sector, this new particle must be unstable to avoid overclosing the universe. The decay of the light mediator could happen due to a weak coupling of the hidden and visible sectors, providing new signatures for direct detection experiments. The SIDM nuclear recoil spectrum is more peaked towards low energies compared to the usual case of contact interactions, because the mediator mass is comparable to the momentum transfer of nuclear recoils. We show that the SIDM signal could be distinguished from that of DM particles with contact interactions by considering the time-average energy spectrum in experiments employing different target materials, or the average and modulated spectra in a single experiment. Using current limits from LUX and SuperCDMS, we also derive strong bounds on the mixing parameter between hidden and visible sector.

   hep-phJCAP(2015)·88 citations
6. 06*

   Lattice inputs to Flavor Physics

   Michele Della Morte🇩🇰

   We review recent lattice results for quark masses and low-energy hadronic parameters relevant for flavor physics. We do that by describing the FLAG initiative, with emphasis on its scope and rating criteria. The emerging picture is that while for light quantities a large number of computations using different approaches exist, and this increases the overall confidence on the final averages/estimates, in the heavy-light case the field is less advanced and, with the exception of decay constants, only a few computations are available. The precision reached for the light quantities is such that electromagnetic (EM) corrections, beyond the point-like approximation, are becoming relevant. We discuss recent computations of the spectrum based on direct simulations of QED+QCD. We also present theoretical developments for including EM effects in leptonic decays. We conclude describing recent results for the $K\to \pi \pi$ transition amplitudes and prospects for tackling hadronic decays on the lattice.

   hep-phhep-lat3 citations
7. 07*

   The perturbative Pomeron with NLO accuracy: Jet-Gap-Jet Observables

   M. Hentschinski🇲🇽

   We give an overview of the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to a jet) in the Balitsky-Fadin-Kuraev-Lipatov (BFKL) formalism at next-to-leading order (NLO). This result allows, together with the NLO non-forward gluon Green function, to perform NLO studies of jet production in diffractive events (Mueller-Tang dijets, as a well-known example)

   hep-phPoS(2015)·0 citations
8. 08*

   Gauge coupling unification in SO(32) heterotic string theory with magnetic fluxes

   Hiroyuki Abe🇯🇵 · Tatsuo Kobayashi🇯🇵 · Hajime Otsuka🇯🇵 · Yasufumi Takano🇯🇵 · Takuya H. Tatsuishi🇯🇵

   We study $SO(32)$ heterotic string theory on torus with magnetic fluxes. Non-vanishing fluxes can lead to non-universal gauge kinetic functions for $SU(3)\times SU(2)\times U(1{)}_Y$ which is the important features of $SO(32)$ heterotic string theory in contrast to the $E_8\times E_8$ theory. It is found that the experimental values of gauge couplings are realized with $\mathcal{O}(1)$ values of moduli fields based on the realistic models with the $SU(3)\times SU(2)\times U(1{)}_Y$ gauge symmetry and three chiral generations of quarks and leptons without chiral exotics.

   hep-phhep-thPTEP(2016)·10 citations
9. 09*

   Pion String evolving in a thermal bath

   Fan Lu🇨🇳 · Qichang Chen🇨🇳 · Hong Mao🇨🇳

   By using the symmetry improved CJT effective formalism, we study a pion string of the $O(4)$ linear sigma model at finite temperature in chiral limit. In terms of the Kibble-Zurek mechanism we reconsider the production and evolution of the pion string in a thermal bath. Finally, we estimate the pion string density and its possible signal during the chiral phase transition.

   hep-phnucl-thPRD(2015)·5 citations
10. 10*

    Strangeness fluctuations from $K-\pi$ interactions

    Bengt Friman🇩🇪 · Pok Man Lo🇵🇱 · Michał Marczenko🇵🇱 · Krzysztof Redlich🇵🇱 · Chihiro Sasaki🇩🇪

    Motivated by recent lattice QCD studies, we explore the effects of interactions on strangeness fluctuations in strongly interacting matter at finite temperature. We focus on S-wave $K\pi$ scattering and discuss the role of the $K_0^{\ast }(800)$ and $K^{\ast }(1430)$ resonances. The interaction contribution is obtained within the S-matrix formulation of thermodynamics, using the empirical $K\pi$ phase shifts as input. We find that the simplified treatment of the interactions in this channel, employed in the hadron resonance gas approach, leads to an overestimate of the strangeness fluctuations. Thus, our calculation indicates that broad resonances must be treated with caution, when modeling QCD thermodynamics in the hadronic phase.

    hep-phnucl-thPRD(2015)·48 citations
11. 11*

    Type-III Seesaw fermionic triplets at the International Linear Collider

    Deepanjali Goswami🇮🇳 · P. Poulose🇮🇳

    The signature of heavy fermionic triplets belonging to Type III seesaw at the International Linear Collider (ILC) is probed. Presence of charged fermionic triplets upto a mass of about $750$ GeV could be established through single production at a 1 TeV ILC with moderate luminosity of 300 fb${}^{-1}$, assuming a fermion triplet-electron mixing of about 0.05. Unlike the case of LHC, the production process is highly sensitive to the mixing, making the process interesting. The single production of neutral triplet is found to be somewhat harder, considering the large SM background present. Pair production of triplets of mass 500 GeV considered at 2 TeV centre of mass energy presents convenient ways to study different mixing scenarios. The production process is sensitive to $V_e$. The pair production along with information regarding single production would be able to identify the mixing scenarios.

    hep-ph0 citations
12. 12*

    Exclusion and discovery via Drell-Yan in the 4DCHM

    Elena Accomando🇬🇧 · Daniele Barducci🇫🇷 · Stefania De Curtis🇮🇹 · Juri Fiaschi🇬🇧 · Stefano Moretti🇬🇧 · Claire Shepherd-Themistocleous🇬🇧

    Searches for Z' bosons are most sensitive in the dilepton channels at hadron colliders. Whilst finite width and interference effects do affect the modifications the presence of BSM physics makes to Standard Model (SM) contributions, generic searches are often designed to minimize these. The experimental approach adopted works well in the case of popular models that predict a single and narrow Z' boson allowing these effects to effectively be neglected. Conversely, finite width and interference effects may have to be taken into account in experimental analyses when such Z' states are wide or where several states are predicted. We explore the consequences of these effects in the 4-Dimensional Composite Higgs Model (4DCHM) which includes multiple new Z' bosons and where the decays of these resonances to non-SM fermions can result in large widths.

    hep-phPoS(2015)·4 citations
13. 13*

    The LHCb pentaquark as a ${\bar{D}}^{\ast }{\Sigma }_c-{\bar{D}}^{\ast }{\Sigma }_c^{\ast }$ molecular state

    L. Roca🇪🇸 · J. Nieves🇪🇸 · E. Oset🇪🇸

    We perform a theoretical analysis of the ${\Lambda }_b\to J/\psi K^{-}p$ reaction from where a recent LHCb experiment extracts a $\Lambda (1405)$ contribution in the $K^{-}p$ spectrum close to threshold and two baryon states of hidden charm in the $J/\psi p$ spectrum. We recall that baryon states of this type have been theoretically predicted matching the mass, width and $J^P$ of the experiment, concretely some states built up from the $J/\psi N$, ${\bar{D}}^{\ast }{\Lambda }_c$, ${\bar{D}}^{\ast }{\Sigma }_c$, $\bar{D}{\Sigma }_c^{\ast }$ and ${\bar{D}}^{\ast }{\Sigma }_c^{\ast }$ coupled channels. We assume that the observed narrow state around 4450 MeV has this nature and we are able to describe simultaneously the shapes and relative strength of the the $K^{-}p$ mass distribution close to threshold and the peak of the $J/\psi p$ distribution, with values of the $J/\psi p$ coupling to the resonance in line with the theoretical ones. The non trivial matching of many properties gives support to a $J^P=3/2^{-}$ assignment to this state and to its nature as a molecular state mostly made of ${\bar{D}}^{\ast }{\Sigma }_c$ and ${\bar{D}}^{\ast }{\Sigma }_c^{\ast }$.

    hep-phPRD(2015)·285 citations
14. 14*

    Introducing SummerTime: a package for high-precision computation of sums appearing in DRA method

    Roman N. Lee🇷🇺 · Kirill T. Mingulov🇷🇺

    We introduce the Mathematica package SummerTime for arbitrary-precision computation of sums appearing in the results of DRA method. So far these results include the following families of the integrals: 3-loop onshell massless vertices, 3-loop onshell mass operator type integrals, 4-loop QED-type tadpoles, 4-loop massless propagators. The package can be used for high-precision numerical computation of the expansion coefficients of the integrals from the above families around arbitrary space-time dimension. In addition, this package can also be used for calculation of multiple zeta values, harmonic polylogarithms and other transcendental numbers expressed in terms of nested sums with factorized summand.

    hep-phComput.Phys.Commun.(2016)·49 citations
15. 15*

    Temperature-dependent cross sections for charmonium dissociation in collisions with kaons and eta mesons in hadronic matter

    Shi-Tao Ji🇨🇳 · Zhen-Yu Shen🇨🇳 · Xiao-Ming Xu🇨🇳

    We study kaon-charmonium and eta-charmonium dissociation reactions. The K-charmonium dissociation and the eta-charmonium dissociation include 27 reactions. Cross sections for the reactions are calculated in the Born approximation, in the quark-interchange mechanism and with a temperature-dependent quark potential. The temperature dependence of peak cross sections of endothermic reactions is linked to the temperature dependence of quark-antiquark relative-motion wave functions, meson masses and the quark potential. Although the eta meson and kaon have similar masses, the energy and temperature dependence of the eta-charmonium dissociation cross sections are quite different from those of the K-charmonium dissociation cross sections. Using the eta-charmonium and pion-charmonium dissociation cross sections, we calculate the ratio of the corresponding dissociation rates in hadronic matter and we find that such rates are comparable at low J/psi momenta.

    hep-phnucl-thJ.Phys.G(2015)·13 citations
16. 16*

    New LHC Benchmarks for the CP-conserving Two-Higgs-Doublet Model

    Howard E. Haber🇺🇸 · Oscar Stal🇸🇪

    We introduce a strategy to study the parameter space of the general, CP-conserving, two-Higgs-doublet Model (2HDM) with a softly broken Z_2-symmetry by means of a new "hybrid" basis. In this basis the input parameters are the measured values of the mass of the observed Standard Model (SM)-like Higgs boson and its coupling strength to vector boson pairs, the mass of the second CP-even Higgs boson, the ratio of neutral Higgs vacuum expectation values, and three additional dimensionless parameters. Using the hybrid basis, we present numerical scans of the 2HDM parameter space where we survey available parameter regions and analyze model constraints. From these results, we define a number of benchmark scenarios that capture different aspects of non-standard Higgs phenomenology that are of interest for future LHC Higgs searches.

    hep-phhep-exEPJC(2015)·147 citations
17. 17*

    AdS/QCD predictions for semileptonic and rare B decays to $\rho$ and $K^{\ast }$ vector mesons

    Mohammad Ahmady🇨🇦 · Sébastien Lord🇨🇦 · Ruben Sandapen🇨🇦

    The light front wavefunction obtained from anti-de Sitter Quantum Chromodynamics is used to calculate the light cone distribution amplitudes for $\rho$ and $K^{\ast }$ vector mesons. These distribution amplitudes are then utilized to calculate the $B\to \rho ,K^{\ast }$ transition form factors via light cone sum rules. Two-parameter fits of our results for low to intermediate momentum transfer $q^2$ that includes the QCD lattice data at high $q^2$ are presented. Consequently, we give predictions for the semileptoic $B\to \rho \ell \nu$ and dileptonic $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ decays.

    hep-phPoS(2015)·3 citations
18. 18*

    NNLO BFKL Pomeron eigenvalue in N=4 SYM

    Nikolay Gromov🇬🇧 · Fedor Levkovich-Maslyuk🇬🇧 · Grigory Sizov🇬🇧

    We obtain an analytical expression for the Next-to-Next-to-Leading order of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) Pomeron eigenvalue in planar SYM N=4 using Quantum Spectral Curve (QSC) integrability based method. The result is verified with more than 60 digits precision using the numerical method developed by us in a previous paper. As a byproduct we developed a general analytic method of solving the QSC perturbatively.

    ↳ hep-thhep-exhep-phPRL(2015)·109 citations
19. 19*

    Dipole Modulation of Cosmic Microwave Background Temperature and Polarization

    Shamik Ghosh🇮🇳 · Rahul Kothari🇮🇳 · Pankaj Jain🇮🇳 · Pranati K. Rath🇮🇳

    We propose a dipole modulation model for the Cosmic Microwave Background Radiation (CMBR) polarization field. We show that the model leads to correlations between l and l+1 multipoles, exactly as in the case of temperature. We obtain results for the case of TE, EE and BB correlations. An anisotropic or inhomogeneous model of primordial power spectrum which leads to such correlations in temperature field also predicts similar correlations in CMBR polarization. We analyze the CMBR temperature and polarization data in order to extract the signal of these correlation between l and l+1 multipoles. Our results for the case of temperature using the latest PLANCK data agree with those obtained by an earlier analysis. A detailed study of the correlation in the polarization data is not possible at present. Hence we restrict ourselves to a preliminary investigation in this case.

    ↳ astro-ph.COhep-phJCAP(2016)·25 citations
20. 20*

    Shear Viscosities of Photons in Strongly Coupled Plasmas

    Di-Lun Yang🇬🇷 · Berndt Müller🇺🇸

    We investigate the shear viscosity of thermalized photons in the quark gluon plasma (QGP) at weak coupling and $\mathcal{N}=4$ super Yang-Mills plasma (SYMP) at both strong and weak couplings. We find that the shear viscosity due to the photon-parton scattering up to the leading order of electromagnetic coupling is suppressed when the coupling of the QGP/SYMP is increased, which stems from the blue-shift of the thermal-photon spectrum at strong coupling. In addition, the shear viscosity rapidly increases near the deconfinement transition in a phenomenological model analogous to the QGP.

    ↳ hep-thhep-phnucl-thPLB(2016)·16 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.