Wed·May 11, 2016Wednesday·May 11, 2016

1. 01*

   New limits on anomalous contributions to the $Wtb$ vertex

   J. L. Birman🇺🇸 · F. Déliot🇫🇷 · M. C. N. Fiolhais🇺🇸 · A. Onofre🇵🇹 · C. M. Pease🇺🇸

   The latest and most precise top quark measurements at the LHC and Tevatron are used to establish new limits on the $Wtb$ vertex. Recent results on the measurements of the $W$-boson helicity fractions and single top quark production cross section are combined in order to establish new limits at 95% CL (confidence level). The allowed regions for these limits are presented, for the first time, in three-dimensional graphics, for both real and imaginary components of the different anomalous couplings, providing a new perspective on the impact of the combination of different physics observables. These results are also combined with the prospected future measurement of the single top quark production cross section and $W$-boson helicity fractions at the LHC.

   hep-phPRD(2016)·34 citations
2. 02*

   Les Houches 2015: Physics at TeV colliders - new physics working group report

   G. Brooijmans · C. Delaunay · A. Delgado · C. Englert · A. Falkowski · B. Fuks · S. Nikitenko · S. Sekmen · (convenors) · D. Barducci · J. Bernon · A. Bharucha and 70 other authors

   We present the activities of the 'New Physics' working group for the 'Physics at TeV Colliders' workshop (Les Houches, France, 1-19 June, 2015). Our report includes new physics studies connected with the Higgs boson and its properties, direct search strategies, reinterpretation of the LHC results in the building of viable models and new computational tool developments. Important signatures for searches for natural new physics at the LHC and new assessments of the interplay between direct dark matter searches and the LHC are also considered.

   hep-phhep-ex49 citations
3. 03*

   $W^{+}{W}^{-}$ production at the LHC: fiducial cross sections and distributions in NNLO QCD

   Massimiliano Grazzini (Zurich U.)🇨🇭 · Stefan Kallweit (Santa Barbara, KITP and U. Mainz, PRISMA)🇩🇪 · Stefano Pozzorini (Santa Barbara, KITP and Zurich U.)🇨🇭 · Dirk Rathlev (DESY)🇩🇪 · Marius Wiesemann (Zurich U.)🇨🇭

   We consider QCD radiative corrections to $W^{+}{W}^{-}$ production at the LHC and present the first fully differential predictions for this process at next-to-next-to-leading order (NNLO) in perturbation theory. Our computation consistently includes the leptonic decays of the $W$ bosons, taking into account spin correlations, off-shell effects and non-resonant contributions. Detailed predictions are presented for the different-flavour channel $pp\to {\mu }^{+}{e}^{-}{\nu }_{\mu }{\bar{\nu }}_e+X$ at $\sqrt{s}=8$ and $13$ TeV. In particular, we discuss fiducial cross sections and distributions in the presence of standard selection cuts used in experimental $W^{+}{W}^{-}$ and $H\to W^{+}{W}^{-}$ analyses at the LHC. The inclusive $W^{+}{W}^{-}$ cross section receives large NNLO corrections, and, due to the presence of a jet veto, typical fiducial cuts have a sizeable influence on the behaviour of the perturbative expansion. The availability of differential NNLO predictions, both for inclusive and fiducial observables, will play an important role in the rich physics programme that is based on precision studies of $W^{+}{W}^{-}$ signatures at the LHC.

   hep-phJHEP(2016)·190 citations
4. 04*

   Factorization and Resummation for Jet Processes

   Thomas Becher🇨🇭 · Matthias Neubert🇩🇪 · Lorena Rothen🇩🇪 · Ding Yu Shao🇨🇭

   From a detailed analysis of cone-jet cross sections in effective field theory, we obtain novel factorization theorems which separate the physics associated with different energy scales present in such processes. The relevant low-energy physics is encoded in Wilson lines along the directions of the energetic particles inside the jets. This multi-Wilson-line structure is present even for narrow-cone jets due to the relevance of small-angle soft radiation. We discuss the renormalization-group equations satisfied by these operators. Their solution resums all logarithmically enhanced contributions to such processes, including non-global logarithms. Such logarithms arise in many observables, in particular whenever hard phase-space constraints are imposed, and are not captured with standard resummation techniques. Our formalism provides the basis for higher-order logarithmic resummations of jet and other non-global observables. As a nontrivial consistency check, we use it to obtain explicit two-loop results for all logarithmically enhanced terms in cone-jet cross sections and verify those against numerical fixed-order computations.

   hep-phJHEP(2016)·115 citations
5. 05*

   Cos(4 phi) azimuthal anisotropy in small-x DIS dijet production beyond the leading power TMD limit

   Adrian Dumitru🇺🇸 · Vladimir Skokov🇺🇸

   We determine the first correction to the quadrupole operator in high-energy QCD beyond the TMD limit of Weizsaecker-Williams and linearly polarized gluon distributions. These functions give rise to isotropic resp. ~ cos 2 phi angular distributions in DIS dijet production. On the other hand, the correction produces a ~ cos 4 phi angular dependence which is suppressed by one additional power of the dijet transverse momentum scale (squared) P^2.

   hep-phPRD(2016)·40 citations
6. 06*

   Joint transverse momentum and threshold resummation beyond NLL

   Gillian Lustermans🇳🇱 · Wouter J. Waalewijn🇳🇱 · Lisa Zeune🇳🇱

   To describe the transverse momentum spectrum of heavy color-singlet production, the joint resummation of threshold and transverse momentum logarithms is investigated. We obtain factorization theorems for various kinematic regimes valid to all orders in the strong coupling, using Soft-Collinear Effective Theory. We discuss how these enable resummation and how to combine regimes. The new ingredients in the factorization theorems are calculated at next-to-leading order, and a range of consistency checks is performed. Our framework goes beyond the current next-to-leading logarithmic accuracy (NLL).

   hep-phnucl-thPLB(2016)·42 citations
7. 07*

   Data-driven Model-independent Searches for Long-lived Particles at the LHC

   Andrea Coccaro🇨🇭 · David Curtin🇺🇸 · H. J. Lubatti🇺🇸 · Heather Russell🇺🇸 · Jessie Shelton🇺🇸

   Neutral long-lived particles (LLPs) are highly motivated by many BSM scenarios, such as theories of supersymmetry, baryogenesis, and neutral naturalness, and present both tremendous discovery opportunities and experimental challenges for the LHC. A major bottleneck for current LLP searches is the prediction of SM backgrounds, which are often impossible to simulate accurately. In this paper, we propose a general strategy for obtaining differential, data-driven background estimates in LLP searches, thereby notably extending the range of LLP masses and lifetimes that can be discovered at the LHC. We focus on LLPs decaying in the ATLAS Muon System, where triggers providing both signal and control samples are available at the LHC Run-2. While many existing searches require two displaced decays, a detailed knowledge of backgrounds will allow for very inclusive searches that require just one detected LLP decay. As we demonstrate for the $h\to XX$ signal model of LLP pair production in exotic Higgs decays, this results in dramatic sensitivity improvements for proper lifetimes $\gtrsim 10$ m. In theories of Neutral Naturalness, this extends reach to glueball masses far below the $\bar{b}b$ threshold. Our strategy readily generalizes to other signal models, and other detector subsystems. This framework therefore lends itself to the development of a systematic, model-independent LLP search program, in analogy to the highly successful simplified-model framework of prompt searches.

   hep-phhep-exPRD(2016)·53 citations
8. 08*

   TeV-scale Pseudo-Dirac Seesaw Mechanisms in an E${}_6$ Inspired Model

   Yi Cai🇦🇺 · Jackson D. Clarke🇦🇺 · Raymond R. Volkas🇦🇺 · Tsutomu T. Yanagida🇯🇵

   TeV-scale seesaw mechanisms are interesting due to their potential testability at existing collider experiments. Herein we propose an E${}_6$-inspired model allowing a TeV-scale pseudo-Dirac singlet neutrino seesaw mechanism with naturally sizeable Yukawa couplings of $\mathcal{O}(10^{-2})$. The model also contains new U(1) gauge interactions (and associated $Z^{\prime }$ bosons with which the singlet neutrinos can be produced at colliders), typically long-lived colour triplet fermions, SU(2) doublet fermions, and a complex scalar - potentially all at the TeV-scale. Additionally we identify three possible explanations for the 750 GeV di-photon excess.

   hep-phPRD(2016)·7 citations
9. 09*

   $R(D^{(\ast )})$ and $\mathcal{B}r(B\to \tau {\nu }_{\tau })$ in a Flipped/Lepton-Specific 2HDM with anomalously enhanced charged Higgs coupling to $\tau$/b

   Lobsang Dhargyal🇮🇳

   Babar, Belle and recently LHCb has reported an excess in the measurements of $R(D^{\ast })$, $R(D)$ and $\mathcal{B}r(B\to \tau {\nu }_{\tau })$ than expected from SM, a possible signature of lepton flavor universality violating NP. In this work we analyze the phenomenological implications for these decay modes in a Flipped/Lepton-Specific 2HDM with anomalously enhanced Yukawa coupling of $H^{\pm }$ to $\tau$/b. When experimental and theoretical errors are added in quadrature, we conclude that this phenomenological extension of SM can give results in agreement within 1$\sigma$ deviation for the combination of $R(D^{(\ast )})$ and $\mathcal{B}r(B\to \tau {\nu }_{\tau })$ compare to about 4$\sigma$ deviation from SM from the latest combined[Babar,Belle,LHCb] experimental data for these observables.

   hep-phPRD(2016)·17 citations
10. 10*

    The BSM-AI project: SUSY-AI - Generalizing LHC limits on Supersymmetry with Machine Learning

    Sascha Caron🇳🇱 · Jong Soo Kim🇪🇸 · Krzysztof Rolbiecki🇪🇸 · Roberto Ruiz de Austri🇪🇸 · Bob Stienen🇳🇱

    A key research question at the Large Hadron Collider (LHC) is the test of models of new physics. Testing if a particular parameter set of such a model is excluded by LHC data is a challenge: It requires the time consuming generation of scattering events, the simulation of the detector response, the event reconstruction, cross section calculations and analysis code to test against several hundred signal regions defined by the ATLAS and CMS experiment. In the BSM-AI project we attack this challenge with a new approach. Machine learning tools are thought to predict within a fraction of a millisecond if a model is excluded or not directly from the model parameters. A first example is SUSY-AI, trained on the phenomenological supersymmetric standard model (pMSSM). About 300,000 pMSSM model sets - each tested with 200 signal regions by ATLAS - have been used to train and validate SUSY-AI. The code is currently able to reproduce the ATLAS exclusion regions in 19 dimensions with an accuracy of at least 93 percent. It has been validated further within the constrained MSSM and a minimal natural supersymmetric model, again showing high accuracy. SUSY-AI and its future BSM derivatives will help to solve the problem of recasting LHC results for any model of new physics. SUSY-AI can be downloaded at http://susyai.hepforge.org/. An on-line interface to the program for quick testing purposes can be found at http://www.susy-ai.org/.

    hep-phhep-exEPJC(2017)·80 citations
11. 11*

    Scattering solutions of Bethe-Salpeter equation in Minkowski and Euclidean spaces

    J. Carbonell🇫🇷 · V.A. Karmanov🇷🇺

    We shortly review different methods to obtain the scattering solutions of the Bethe-Salpeter equation in Minkowski space. We emphasize the possibility to obtain the zero energy observables in terms of the Euclidean scattering amplitude.

    hep-phhep-thnucl-thFew Body Syst.(2016)·1 citation
12. 12*

    Flavor Violation in the Scalar Sector

    Joachim Kopp (MITP, Johannes Gutenberg University Mainz)🇩🇪

    In many extensions of the Standard Model, the alignment in flavor space of the fermion mass matrices and the Yukawa coupling matrices can be broken. The physical scalar boson $h(125)$ could then have flavor changing couplings. In this talk, we summarize constraints on such couplings from rare decay searches, and we investigate current and future detection prospects at the LHC. We emphasize the importance of several yet unexplored final states: (i) anomalous single top + $h$ production in $pp\to th$, arising from $tuh$ couplings (but not from the more widely studied $tch$ couplings); (ii) $pp\to t+(H^0\to hh)$ through $tuh$ couplings in the context of a Two Higgs Doublet Model (2HDM), perhaps the simplest model with flavor violation in the scalar sector; (iii) $pp\to H^0\to \tau \mu$ in the 2HDM context. For all of these processes, we perform a detailed phenomenological studies. Finally, we comment on the possibility of flavor violation combined with CP violation, which may be interesting if the current CMS hint for $h\to \tau \mu$ gets corroborated.

    hep-ph4 citations
13. 13*

    $Z^{\prime }$, Higgses and heavy neutrinos in $U(1{)}^{\prime }$ models: from the LHC to the GUT scale

    Elena Accomando🇬🇧 · Claudio Coriano🇮🇹 · Luigi Delle Rose🇬🇧 · Juri Fiaschi🇬🇧 · Carlo Marzo🇮🇹 · Stefano Moretti🇬🇧

    We study a class of non-exotic minimal $U(1{)}^{\prime }$ extensions of the Standard Model, which includes all scenarios that are anomaly-free with the ordinary fermion content augmented by one Right-Handed neutrino per generation, wherein the new Abelian gauge group is spontaneously broken by the non-zero Vacuum Expectation Value of an additional Higgs singlet field, in turn providing mass to a $Z^{\prime }$ state. By adopting the $B-L$ example, whose results can be recast into those pertaining to the whole aforementioned class, and allowing for both scalar and gauge mixing, we first extract the surviving parameter space in presence of up-to-date theoretical and experimental constraints. Over the corresponding parameter configurations, we then delineate the high energy behaviour of such constructs in terms of their stability and perturbativity. Finally, we highlight key production and decay channels of the new states entering the spectra of this class of models, i.e., heavy neutrinos, a second Higgs state and the $Z^{\prime }$, which are amenable to experimental investigation at the Large Hadron Collider. We therefore set the stage to establish a direct link between measurements obtainable at the Electro-Weak scale and the dynamics of the underlying model up to those where a Grand Unification Theory embedding a $U(1{)}^{\prime }$ can be realised.

    hep-phJHEP(2016)·61 citations
14. 14*

    Testing keV sterile neutrino dark matter in future direct detection experiments

    Miguel D. Campos🇩🇪 · Werner Rodejohann🇩🇪

    We determine constraints on sterile neutrino warm dark matter through direct detection experiments, taking XENON100, XENON1T and DARWIN as examples. If keV-scale sterile neutrinos scatter inelastically with bound electrons of the target material, an electron recoil signal is generated. This can be used to set limits on the sterile neutrino mass and its mixing with the active sector. While not competitive with astrophysical constraints from X-ray data, the constraints are the first direct laboratory bounds on sterile neutrino warm dark matter, and will be in some parts of parameter space the strongest limits on keV-scale neutrinos.

    hep-phastro-ph.HEhep-exPRD(2016)·34 citations
15. 15*

    Heavy pentaquark states $P_c(4380)$ and $P_c(4450)$ in the $J/\psi$ production induced by pion beams off the nucleon

    Sang-Ho Kim🇰🇷 · Hyun-Chul Kim🇰🇷 · Atsushi Hosaka🇯🇵

    In this study, we investigate the $J/\psi$ production induced by pion beams off the nucleon, particularly the heavy pentaquarks $P_c(4380)$ and $P_c(4450)$ in intermediate states, based on a hybridized Regge model. The process involving $\rho$ and $\pi$ meson exchange in the $t$ channel is considered as background, and the heavy pentaquark exchange is included in the $s$ channel. The coupling constants such as the $\rho NN$ and $\pi NN$ vertices are taken from the $NN$ potentials, whereas those for the $J/\psi \rho \pi$ and $J/\psi \pi \pi$ vertices are determined by using experimental data based on the branching ratios. In order to estimate the $P_c(4380)$ and $P_c(4450)$ coupling constants, we use the experimental upper limit on the total cross section as a guide for the $\pi N\to J/\psi N$ reaction. The background total cross section is the order of $10^{-4}-10^{-3}$ nb. In the vicinity of the heavy pentaquark masses, the total cross section reaches about $1$ nb.

    hep-phhep-exPLB(2016)·32 citations
16. 16*

    Levy distributions for one-dimensional analysis of the Bose-Einstein correlations

    V. A. Okorokov (National Research Nuclear University MEPhI)🇷🇺

    A general study of relations between the parameters of two centrally-symmetric Levy distributions, often used for one-dimensional investigation of Bose - Einstein correlations, is given for the first time. These relations of the strength of correlations and of the radius of the emission region take into account possible various finite ranges of the Lorentz invariant four-momentum difference for two centrally-symmetric Levy distributions. In particular, special cases of the relations are investigated for Cauchy and normal (Gaussian) distributions. The mathematical formalism is verified using the recent measurements given a generalized centrally-symmetric Levy distribution is used. The reasonable agreement is observed between estimations and experimental results for all available types of strong interaction processes and collision energies.

    hep-phAdv.High Energy Phys.(2017)·4 citations
17. 17*

    New Physics in the Flavour Sector

    Andreas Crivellin🇨🇭

    Several experiments observed deviations from the Standard Model (SM) in the flavour sector: LHCb found a $4-5\sigma$ discrepancy compared to the SM in $b\to s{\mu }^{+}{\mu }^{-}$ transitions (recently supported by an Belle analysis) and CMS reported a non-zero measurement of $h\to \mu \tau$ with a significance of $2.4\sigma$. Furthermore, BELLE, BABAR and LHCb founds hints for the violation of flavour universality in $B\to D^{(\ast )}\tau \nu$. In addition, there is the long-standing discrepancy in the anomalous magnetic moment of the muon. Interestingly, all these anomalies are related to muons and taus, while the corresponding electron channels seem to be SM like. This suggests that these deviations from the SM might be correlated and we briefly review some selected models providing simultaneous explanations.

    hep-phhep-ex8 citations
18. 18*

    Near-threshold production of heavy quarks with QQbar_threshold

    M. Beneke🇩🇪 · Y. Kiyo🇯🇵 · A. Maier🇬🇧 · J. Piclum🇩🇪

    We describe the QQbar_threshold library for computing the production cross section of heavy quark-antiquark pairs near threshold at electron-positron colliders. The prediction includes all presently known QCD, electroweak, Higgs, and nonresonant corrections in the combined nonrelativistic and weak-coupling expansion.

    hep-phComput.Phys.Commun.(2016)·53 citations
19. 19*

    The SM extensions with additional light scalar singlet, nonrenormalizable Yukawa interactions and $(g-2{)}_{\mu }$

    S.N. Gninenko🇷🇺 · N.V. Krasnikov🇷🇺

    We consider the SM extension with additional light real singlet scalar, right-handed neutrino and nonrenormalizable Yukawa interaction for the first two generations. We show that the proposed model can explain the observed $(g-2)$ muon anomaly. Phenomenological consequences as flavour violating decays $\tau \to \mu \mu \mu ,\mu \mu e,\mu ee$ are briefly discussed. We also propose the $U_R(1)$ gauge generalization of the SM with complex scalar singlet and nonzero right-handed charges for the first two generations.

    hep-phEPJ Web Conf.(2016)·8 citations
20. 20*

    Complete Study of Hadroproduction of a ${\rm Y}$ Meson Associated with a Prompt $J/\psi$

    Hua-Sheng Shao🇨🇭 · Yu-Jie Zhang🇨🇳

    We present the first complete study of ${\rm Y}$ and prompt $J/\psi$ production from single-parton scattering, including the complete $\mathcal{O}({\alpha }_S^6)$ color-singlet contribution, the $\mathcal{O}({\alpha }_S^2{\alpha }^2)$ electroweak contribution, the complete nonrelativistic S-wave and P-wave color-octet contribution as well as the feeddown contribution. Our study was motivated by the recent evidence reported by D0 Collaboration of prompt $J/\psi$ and ${\rm Y}$ simultaneous production at the Tevatron. With our complete evaluation, we are able to refine the determination of the double parton scattering contribution made by D0 Collaboration. We find that the effective cross section characterizing the importance of double-parton scatterings is ${\sigma }_{\mathrm{eff}}\le 8.2$ mb at $68\%$ confidence level from the D0 measurement.

    hep-phhep-exnucl-exnucl-thPRL(2016)·45 citations
21. 21*

    Production of the Doubly Charmed Baryons at the SELEX experiment -- The double intrinsic charm approach

    Sergey Koshkarev🇪🇪 · Vladimir Anikeev🇷🇺

    The high production rate and $⟨x_F⟩>0.33$ of the doubly charmed baryons measured by the SELEX experiment is not amenable to perturbative QCD analysis. In this paper we calculate the production of the doubly heavy baryons with the double intrinsic charm Fock states whose existence is rigorously predicted by QCD. The production rate and the longitudinal momentum distribution are both reproduced. We also show that the production rates of the doubly charmed baryons and double $J/\psi$ production observed by NA3 collaboration are comparable. Recent experimental results are reviewed. The production cross section of the doubly charmed baryons at a fixed-target experiment at the LHC is presented.

    hep-phPLB(2017)·36 citations
22. 22*

    Regarding the Radion in Randall-Sundrum Models with Brane Curvature

    Barry M. Dillon🇬🇧 · Damien P. George🇬🇧 · Kristian L. McDonald🇦🇺

    In Randall-Sundrum models, one typically expects the radion to be the lightest new "gravity" state, as it is dual to a composite pseudo-Goldstone boson associated with conformal symmetry breaking in the IR. Here, we investigate the effects of localized brane curvature on the properties of the radion in Goldberger-Wise stabilized Randall-Sundrum models. We point out that both the radion mass and coupling to brane matter are sensitive to the brane curvature. Radion/Higgs kinetic mixing, via an IR-localized non-minimal coupling to the Higgs, is also investigated, in relation to the ghost-like radion that can occur for $\mathcal{O}(10)$ values of the IR curvature (as required to significantly suppress the first Kaluza-Klein graviton mass). We also discuss a class of speculative IR localized terms involving the radion. Basic comments regarding the dual 4D theory are offered.

    hep-phPRD(2016)·13 citations
23. 23*

    Analysis of beta-decay data acquired at the Physikalisch-Technische Bundesanstalt: evidence of a solar influence

    Peter Sturrock🇺🇸 · Gideon Steinitz🇮🇱 · Ephraim Fischbach🇺🇸 · Alexander Parkhomov🇷🇺 · Jeffrey Scargle🇺🇸

    According to an article entitled Disproof of solar influence on the decay rates of 90Sr/90Y by Kossert and Nähle of the Physikalisch-Technische Bundesanstalt (PTB) [1], the PTB measurements show no evidence of variability. We show that, on the contrary, those measurements reveal strong evidence of variability, including an oscillation at 11 year-1 that is suggestive of an influence of internal solar rotation. An analysis of radon beta-decay data acquired at the Geological Survey of Israel (GSI) Laboratory for the same time interval yields strong confirmation of this oscillation.

    hep-phphysics.ins-detAstropart.Phys.(2016)·13 citations
24. 24*

    A possible interpretation of the Higgs mass by the cosmological attractive relaxion

    Fa Peng Huang🇨🇳 · Yifu Cai🇨🇳 · Hong Li🇨🇳 · Xinmin Zhang🇨🇳

    Recently, a novel idea has been proposed to relax the electroweak hierarchy problem through the cosmological inflation and the axion periodic potential. Here, we further assume that only the attractive inflation is needed to explain the light mass of the Higgs boson, where we do not need a specified periodic potential of the axion field. Attractive inflation during the early universe drives the Higgs boson mass from the large value in the early universe to the small value at present, where the Higgs mass is an evolving parameter of the Universe. Thus, the small Higgs mass can technically originate from the cosmological evolution rather than dynamical symmetry or anthropics. Further, we study the possible collider signals or constraints at future lepton collier and the possible constraints from the muon anomalous magnetic moment. A concrete attractive relaxion model is also discussed, which is consistent with the data of Planck 2015.

    hep-phCPC(2016)·13 citations
25. 25*

    Preface to the 18th workshop "What comes beyond the standard models", Bled July 11--19, 2015, and links to the talks in the proceedings

    N. S. Mankoc Borstnik🇸🇮 · H. F. B. Nielsen · M. Y. Khlopov🇫🇷 · D. Lukman

    The contribution contains the preface to the Proceedings to the 18th Workshop "What Comes Beyond the Standard Models", Bled, July 11 - 19, 2015, published in Bled workshops in physics, Vol.16, No. 2, DMFA-Zaloznistvo, Ljubljana, Dec. 2015, links to (most of) the published contributions and section (by M.Yu. Khlopov) on VIA at Bled 2015.

    hep-phhep-exhep-thBled Workshops Phys.(2015)·0 citations
26. 26*

    Anatomy of the sign-problem in heavy-dense QCD

    Nicolas Garron🇬🇧 · Kurt Langfeld🇬🇧

    QCD at finite densities of heavy quarks is investigated using the density-of-states method. The phase factor expectation value of the quark determinant is calculated to unprecedented precision as a function of the chemical potential. Results are validated using those from a reweighting approach where the latter can produce a significant signal-to-noise ratio. We confirm the particle-hole symmetry at low temperatures, find a strong sign problem at intermediate values of the chemical potential, and an inverse Silver Blaze feature for chemical potentials close to the onset value: here, the phase quenched theory underestimates the density of the full theory.

    ↳ hep-lathep-phhep-thEPJC(2016)·36 citations
27. 27*

    The low abundance and insignificance of dark discs in simulated Milky Way galaxies

    Matthieu Schaller (1)🇬🇧 · Carlos S. Frenk (1)🇬🇧 · Azadeh Fattahi (2)🇨🇦 · Julio F. Navarro (2)🇨🇦 · Kyle A. Oman (2)🇨🇦 · Till Sawala (3) ((1) ICC, Durham University, (2) University of Victoria, (3) University of Helsinki)🇫🇮

    We investigate the presence and importance of dark matter discs in a sample of 24 simulated Milky Way galaxies in the APOSTLE project, part of the EAGLE programme of hydrodynamic simulations in Lambda-CDM cosmology. It has been suggested that a dark disc in the Milky Way may boost the dark matter density and modify the velocity modulus relative to a smooth halo at the position of the Sun, with ramifications for direct detection experiments. From a kinematic decomposition of the dark matter and a real space analysis of all 24 halos, we find that only one of the simulated Milky Way analogues has a detectable dark disc component. This unique event was caused by a merger at late time with an LMC-mass satellite at very low grazing angle. Considering that even this rare scenario only enhances the dark matter density at the solar radius by 35% and affects the high energy tail of the dark matter velocity distribution by less than 1%, we conclude that the presence of a dark disc in the Milky Way is unlikely, and is very unlikely to have a significant effect on direct detection experiments.

    ↳ astro-ph.GAastro-ph.COhep-phMNRAS(2016)·20 citations
28. 28*

    Prospects for annihilating Dark Matter towards Milky Way's dwarf galaxies by the Cherenkov Telescope Array

    Valentin Lefranc🇫🇷 · Paolo Panci🇫🇷 · Gary A. Mamon🇫🇷

    We derive the Cherenkov Telescope Array (CTA) sensitivity to dark matter (DM) annihilation in several primary channels, over a broad range of DM masses. These sensitivities are estimated when CTA is pointed towards a large sample of Milky Way's dwarf spheroidal galaxies (dSphs) with promising $J$-factors and small statistical uncertainties. This analysis neglects systematic uncertainties, which we estimate at the level of at least 1 dex. We also present sensitivities on the annihilation cross section from a combined analysis of 4 dSphs. We assess the CTA sensitivity by: $i)$ using, for each dSph, a recent determination of the $J$-factor and its statistical error; $ii)$ considering the most up-to-date cosmic ray background; and $iii)$ including both spatial and spectral terms in the likelihood analysis. We find that a joint spectral and spatial analysis improves the CTA sensitivity, in particular for primary channels with sharp features in the $\gamma$-ray energy spectrum and for dSphs with steep $J$-factor profiles, as deduced from the internal kinematics. The greatest sensitivities are obtained for observations of Ursa Minor among the classical dSphs and of Ursa Major II for ultra-faint dSphs.

    ↳ astro-ph.HEhep-exhep-phJCAP(2016)·36 citations
29. 29*

    Dynamical supersymmetry breaking on magnetized tori and orbifolds

    Hiroyuki Abe🇯🇵 · Tatsuo Kobayashi🇯🇵 · Keigo Sumita🇯🇵

    We construct several dynamical supersymmetry breaking (DSB) models within a single ten-dimensional supersymmetric Yang-Mills (SYM) theory, compactified on magnetized tori with or without orbifolding. We study the case that the supersymmetry breaking is triggered by a strong dynamics of $SU(N_C)$ SYM theory with $N_F$ flavors contained in the four-dimensional effective theory. We show several configurations of magnetic fluxes and orbifolds, those potentially yield, below the compactification scale, the field contents and couplings required for triggering DSB. We especially find a class of self-complete DSB models on orbifolds, where all the extra fields are eliminated by the orbifold projection and DSB successfully occurs within the given framework. Comments on some perspectives for associating the obtained DSB models with the other sectors, such as the visible sector and another hidden sector for, e.g., stabilizing moduli, are also given.

    ↳ hep-thhep-phNPB(2016)·5 citations
30. 30*

    Latent heat at the first order phase transition point of SU(3) gauge theory

    Mizuki Shirogane🇯🇵 · Shinji Ejiri🇯🇵 · Ryo Iwami🇯🇵 · Kazuyuki Kanaya🇯🇵 · Masakiyo Kitazawa🇯🇵

    We calculate the energy gap (latent heat) and pressure gap between the hot and cold phases of the SU(3) gauge theory at the first order deconfining phase transition point. We perform simulations around the phase transition point with the lattice size in the temporal direction Nt=6, 8 and 12 and extrapolate the results to the continuum limit. We also investigate the spatial volume dependence. The energy density and pressure are evaluated by the derivative method with non-perturabative anisotropy coefficients. We adopt a multi-point reweighting method to determine the anisotropy coefficients. We confirm that the anisotropy coefficients approach the perturbative values as Nt increases. We find that the pressure gap vanishes at all values of Nt when the non-perturbative anisotropy coefficients are used. The spatial volume dependence in the latent heat is found to be small on large lattices. Performing extrapolation to the continuum limit, we obtain $\Delta ϵ/T^4=0.75\pm 0.17$ and $\Delta (ϵ-3p)/T^4=0.623\pm \mathrm{0.056.}$

    ↳ hep-lathep-phPRD(2016)·34 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.