Wed·Sep 21, 2016Wednesday·September 21, 2016

1. 01*

   Angular Structure of Jet Quenching Within a Hybrid Strong/Weak Coupling Model

   Jorge Casalderrey-Solana🇬🇧 · Doga Gulhan🇨🇭 · Guilherme Milhano🇵🇹 · Daniel Pablos🇪🇸 · Krishna Rajagopal🇺🇸

   Within the context of a hybrid strong/weak coupling model of jet quenching, we study the modification of the angular distribution of the energy within jets in heavy ion collisions, as partons within jet showers lose energy and get kicked as they traverse the strongly coupled plasma produced in the collision. To describe the dynamics transverse to the jet axis, we add the effects of transverse momentum broadening into our hybrid construction, introducing a parameter $K\equiv \hat{q}/T^3$ that governs its magnitude. We show that, because of the quenching of the energy of partons within a jet, even when $K\ne 0$ the jets that survive with some specified energy in the final state are narrower than jets with that energy in proton-proton collisions. For this reason, many standard observables are rather insensitive to $K$. We propose a new differential jet shape ratio observable in which the effects of transverse momentum broadening are apparent. We also analyze the response of the medium to the passage of the jet through it, noting that the momentum lost by the jet appears as the momentum of a wake in the medium. After freezeout this wake becomes soft particles with a broad angular distribution but with net momentum in the jet direction. We show that the particles coming from the response of the medium to the momentum and energy deposited in it leads to a correlation between the momentum of soft particles well separated from the jet in angle with the direction of the jet momentum, and find qualitative but not quantitative agreement with experimental data on observables designed to extract such a correlation. By confronting the results that we obtain upon introducing transverse momentum broadening and the response of the medium to the jet with available jet data, we highlight the importance of these processes for understanding the internal, soft, angular structure of high energy jets.

   hep-phnucl-thJHEP(2017)·205 citations
2. 02*

   Starobinsky-Like Inflation and Neutrino Masses in a No-Scale SO(10) Model

   John Ellis🇬🇧 · Marcos A. G. Garcia🇺🇸 · Natsumi Nagata🇯🇵 · Dimitri V. Nanopoulos🇺🇸 · Keith A. Olive🇺🇸

   Using a no-scale supergravity framework, we construct an SO(10) model that makes predictions for cosmic microwave background observables similar to those of the Starobinsky model of inflation, and incorporates a double-seesaw model for neutrino masses consistent with oscillation experiments and late-time cosmology. We pay particular attention to the behaviour of the scalar fields during inflation and the subsequent reheating.

   hep-phastro-ph.COgr-qchep-thJCAP(2016)·35 citations
3. 03*

   Dimesoatoms production in high energy collisions

   L. Afanasyev🇷🇺 · S. Gevorkyan🇷🇺 · O. Voskresenskaya🇷🇺

   The production of two meson electromagnetic bound states and free meson pairs ${\pi }^{+}{\pi }^{-}$, $K^{+}{K}^{-}$, ${\pi }^{+}{K}^{\mp }$ in relativistic collisions has been considered. It is shown that making use of the exact Coulomb wave function for dimesoatom (DMA) allows one to calculate the yield of any nS state with desired accuracy. The relative probabilities of production of DMA and meson pairs in the free state are estimated. The amplitude of DMA transition from 1S to 2P state, which is essential for the pionium Lamb shift measurements, has been obtained.

   hep-ph0 citations
4. 04*

   Supernova Constraints on Massive (Pseudo)Scalar Coupling to Neutrinos

   Lucien Heurtier🇧🇪 · Yongchao Zhang🇧🇪

   In this paper we derive constraints on the emission of a massive (pseudo)scalar $S$ from annihilation of neutrinos in the core of supernovae through the dimension-4 coupling $\nu \nu S$, as well as the effective dimension-5 operator $\frac{1}{\Lambda }(\nu \nu )(SS)$. While most of earlier studies have focused on massless or ultralight scalars, our analysis involves scalar with masses of order $\mathrm{eV}-\mathrm{GeV}$ which can be copiously produced during the explosion of supernovae, whose core temperature is generally of order $T\sim \mathcal{O}(10)$ MeV. From the luminosity and deleptonization arguments regarding the observation of SN1987A, we exclude a large range of couplings $10^{-12}\lesssim |g_{\alpha \beta }|\lesssim 10^{-5}$ for the dimension-4 case, depending on the neutrino flavours involved and the scalar mass. In the case of dimension-5 operator, for a scalar mass from MeV to 100 MeV the coupling $h_{\alpha \beta }$ get constrained from $10^{-6}$ to $10^{-2}$, with the cutoff scale explicitly set $\Lambda =1$ TeV. We finally show that if the neutrino burst of a nearby supernova explosion is detected by Super-Kamiokande and IceCube, the constraints will be largely reinforced.

   hep-phastro-ph.COastro-ph.HEastro-ph.SRJCAP(2017)·100 citations
5. 05*

   A UV complete partially composite-pNGB Higgs

   Jamison Galloway🇺🇸 · Alexander L. Kagan🇺🇸 · Adam Martin🇺🇸

   We explore an electroweak symmetry breaking (EWSB) scenario based on the mixture of a fundamental Higgs doublet and an SU(4)/Sp(4) composite pseudo-Nambu-Goldstone doublet -- a particular manifestation of bosonic technicolor/induced EWSB. Taking the fundamental Higgs mass parameter to be positive, EWSB is triggered by the mixing of the doublets. This setup has several attractive features and phenomenological consequences, which we highlight: i) Unlike traditional bosonic technicolor models, the hierarchy between ${\Lambda }_{\mathrm{TC}}$ and the electroweak scale depends on vacuum (mis)alignment and can be sizable, yielding an attractive framework for natural EWSB; ii) As the strong sector is based on SU(4)/Sp(4), a fundamental (UV-complete) description of the strong sector is possible, that is informed by the lattice; iii) The lightest vector resonances occur in the 10-plet, 5-plet and singlet of Sp(4). Misalignment leads to a 10-plet "parity-doubling" cancelation in the $S$ parameter, and a suppressed 5-plet contribution; iv) Higgs coupling deviations are typically of $\mathcal{O}(1\%)$; v) The 10-plet isotriplet resonances decay dominantly to a massive technipion and a gauge boson, or to technipion pairs, rather than to gauge boson or fermion pairs; moreover, their couplings to fermions are small. Thus, the bounds on this setup from conventional heavy-vector-triplet searches are weak. A supersymmetric $U(1{)}_R$ symmetric realization is briefly described.

   hep-phPRD(2017)·54 citations
6. 06*

   Gauged Lepton Flavour

   R. Alonso🇨🇭 · E. Fernandez Martinez🇪🇸 · M. B. Gavela🇪🇸 · B. Grinstein🇺🇸 · L. Merlo🇪🇸 · P. Quilez🇪🇸

   The gauging of the lepton flavour group is considered in the Standard Model context and in its extension with three right-handed neutrinos. The anomaly cancellation conditions lead to a Seesaw mechanism as underlying dynamics for all leptons; requiring in addition a phenomenologically viable setup leads to Majorana masses for the neutral sector: the type I Seesaw Lagrangian in the Standard Model case and the inverse Seesaw in the extended model. Within the minimal extension of the scalar sector, the Yukawa couplings are promoted to scalar fields in the bifundamental of the flavour group. The resulting low-energy Yukawa couplings are proportional to inverse powers of the vacuum expectation values of those scalars; the protection against flavour changing neutral currents differs from that of Minimal Flavor Violation. In all cases, the $\mu -\tau$ flavour sector exhibits rich and promising phenomenological signals.

   hep-phJHEP(2016)·43 citations
7. 07*

   Gluon fusion and $b\bar{b}$ corrections to $H{W}^{+}{W}^{-}/HZZ$ production in the POWHEG-BOX

   Julien Baglio🇩🇪

   The study of the Higgs boson properties is one of the most important tasks to be accomplished in the next years, at the Large Hadron Collider (LHC) and at future colliders such as the Future Circular Collider in hadron-hadron mode (FCC-hh), the potential 100 TeV follow-up of the LHC machine. In this view the precise study of the Higgs couplings to weak gauge bosons is crucial and requires as much information as possible. After the recent calculation of the next-to-leading order QCD corrections to the production cross sections and differential distributions of a Standard Model Higgs boson in association with a pair of weak bosons, matched with parton shower in the POWHEG-BOX framework, we present the gluon fusion correction $gg\to H{W}_{}^{+}{W}_{}^{-}(HZZ)$ to the process $pp\to H{W}_{}^{+}{W}_{}^{-}(HZZ)$. This correction can be sizeable and amounts to $+3\%$ ($+10\%$) in the $H{W}_{}^{+}{W}_{}^{-}$ process and $+5\%$ ($+18\%$) in the $HZZ$ process at the LHC (FCC-hh). We also present the first study of the impact of the bottom--quark initiated channels $b\bar{b}\to H{W}_{}^{+}{W}_{}^{-}/HZZ$ and find that they induce a significant $+18\%$ correction in the $H{W}_{}^{+}{W}_{}^{-}$ channel at the FCC-hh. We present results on total cross sections and distributions at the LHC and at the FCC-hh.

   hep-phhep-exPLB(2017)·8 citations
8. 08*

   The RG-improved Twin Higgs effective potential at NNLL

   Davide Greco🇨🇭 · Kin Mimouni🇨🇭

   We present the Renormalization Group improvement of the Twin Higgs effective potential at cubic order in logarithmic accuracy. We first introduce a model-independent low-energy effective Lagrangian that captures both the pseudo-Nambu-Goldstone boson nature of the Higgs field and the twin light degrees of freedom charged under a copy of the Standard Model. We then apply the background field method to systematically re-sum all the one loop diagrams contributing to the potential. We show how this technique can be efficient to implicitly renormalize the higher-dimensional operators in the twin sector without classifying all of them. A prediction for the Higgs mass in the Twin Higgs model is derived and found to be of the order of $M_H\sim 120\text{GeV}$ with an ultraviolet cut-off $m_{\ast }\sim 10-20\text{TeV}$. Irrespective of any possible ultraviolet completion of the low-energy Lagrangian, the infrared degrees of freedom alone are therefore enough to account for the observed value of the Higgs mass through running effects.

   hep-phJHEP(2016)·7 citations
9. 09*

   Glue spin and helicity in proton from lattice QCD

   Yi-Bo Yang🇺🇸 · Raza Sabbir Sufian🇺🇸 · Andrei Alexandru🇺🇸 · Terrence Draper🇺🇸 · Michael J. Glatzmaier🇺🇸 · Keh-Fei Liu🇺🇸 · Yong Zhao🇺🇸

   We report the first lattice QCD calculation of the glue spin in the nucleon. The lattice calculation is carried out with valence overlap fermions on 2+1 flavor DWF gauge configurations on four lattice spacings and four volumes including an ensemble with physical values for the quark masses. The glue spin $S_G$ in the Coulomb gauge in the $\overline{\text{MS}}$ scheme is obtained with the 1-loop perturbative matching. We find the results fairly insensitive to lattice spacing and quark masses. We also find that the proton momentum dependence of $S_G$ in the range $0\le |\vec{p}|<1.5$ GeV is very mild, and we determine it in the large momentum limit to be $S_G=0.251(47)(16)$ at the physical pion mass in the $\overline{\text{MS}}$ scheme at ${\mu }^2=10$ GeV${}^2$. If the matching procedure in large momentum effective theory is neglected, $S_G$ is equal to the glue helicity measured in high-energy scattering experiments.

   hep-phhep-latnucl-thPRL(2017)·99 citations
10. 10*

    Quarkonium Production in an Improved Color Evaporation Model

    Yan-Qing Ma🇨🇳 · Ramona Vogt🇺🇸

    We propose an improved version of the color evaporation model to describe heavy quarkonium production. In contrast to the traditional color evaporation model, we impose the constraint that the invariant mass of the intermediate heavy quark-antiquark pair to be larger than the mass of produced quarkonium. We also introduce a momentum shift between heavy quark-antiquark pair and the quarkonium. Numerical calculations show that our model can describe the charmonium yields as well as ratio of ${\psi }^{\prime }$ over $J/\psi$ better than the traditional color evaporation model.

    hep-phhep-exPRD(2016)·149 citations
11. 11*

    Power corrections and renormalons in Transverse Momentum Distributions

    Ignazio Scimemi🇪🇸 · Alexey Vladimirov🇩🇪

    We study the power corrections to Transverse Momentum Distributions (TMDs) by analyzing renormalon divergences of the perturbative series. The renomalon divergences arise independently in two constituents of TMDs: the rapidity evolution kernel and the small-b matching coefficient. The renormalon contributions have a non-trivial dependence on the Bjorken variable and the transverse distance. We discuss the consistency requirements for power corrections for TMDs and suggest inputs for the TMD phenomenology in accordance with this study. Both unpolarized quark TMD parton distribution function and fragmentation function are considered.

    hep-phhep-exhep-latJHEP(2017)·59 citations
12. 12*

    Review of LHC experimental results on low mass bosons in multi Higgs models

    Robin Aggleton🇬🇧 · Daniele Barducci🇫🇷 · Nils-Erik Bomark🇳🇴 · Stefano Moretti🇬🇧 · Claire Shepherd-Themistocleous🇬🇧

    A number of searches at the LHC looking for low mass ($2m_{\mu }-62\mathrm{GeV}$) bosons in $\sqrt{s}=8\mathrm{TeV}$ data have recently been published. We summarise the most pertinent ones, and look at how their limits affect a variety of supersymmetric and non-supersymmetric models which can give rise to such light bosons: the 2HDM (Types I and II), the NMSSM, and the nMSSM.

    hep-phhep-exJHEP(2017)·29 citations
13. 13*

    A neutrino mass model with S3 symmetry and see-saw interplay

    Soumita Pramanick🇮🇳 · Amitava Raychaudhuri (University of Calcutta)🇮🇳

    We develop a see-saw model for neutrino masses and mixing with an S3\times Z3 symmetry. It involves an interplay of Type-I and Type-II see-saw contributions of which the former is subdominant. The S3 \times Z3 quantum numbers of the fermion and scalar fields are chosen such that the Type-II see-saw generates a mass matrix which incorporates the atmospheric mass splitting and sets \theta_{23} = \pi/4. The solar splitting and \theta_{13} are absent, while the third mixing angle can achieve any value, \theta_{12}^0. Specific choices of \theta_{12}^0 are of interest, e.g., 35.3^\circ (tribimaximal), 45.0^\circ (bimaximal), 31.7^\circ (golden ratio), and 0^\circ (no solar mixing). The role of the Type-I see-saw is to nudge all the above into the range indicated by the data. The model results in novel interrelationships between these quantities due to their common origin, making it readily falsifiable. For example, normal (inverted) ordering is associated with \theta_{23} in the first (second) octant. CP-violation is controlled by phases in the right-handed neutrino Majorana mass matrix, M_{\nu R}. In their absence, only normal ordering is admissible. When M_{\nu R} is complex the Dirac CP-phase, \delta, can be large, i.e., \sim \pm \pi/2, and inverted ordering is also allowed. The preliminary results from T2K and NOVA which favour normal ordering and \delta \sim -\pi/2 are indicative, in this model, of a lightest neutrino mass of 0.05 eV or more.

    hep-phhep-exPRD(2016)·20 citations
14. 14*

    Multi-particle correlations and KNO scaling in the medium-induced jet evolution

    Miguel A. Escobedo🇫🇷 · Edmond Iancu🇫🇷

    We study the gluon distribution produced via successive medium-induced branchings by an energetic jet propagating through a weakly-coupled quark-gluon plasma. We show that under suitable approximations the evolution of the jet can be described as a classical stochastic process, which is exactly solvable. For this process, we construct exact analytic solutions for all the n-point correlation functions (the n-body densities in the space of energy). The corresponding results for the one-point and the two-point functions were already known, but those for the higher-point functions are new. These results demonstrate strong correlations associated with the existence of common ancestors in the branching process. By integrating these n-point functions over the gluon energies, we deduce the mean gluon multiplicity $⟨N⟩$ as well as the higher moments $⟨N^p⟩$ with $p\ge 2$. We find that the multiplicities of the soft gluons are parametrically large and show a remarkable regularity, known as Koba-Nielsen-Olesen (KNO) scaling: the reduced moments $⟨N^p⟩/⟨N{⟩}^p$ are pure numbers, independent of any of the physical parameters of the problem. We recognize a special negative binomial distribution which is characterized by large statistical fluctuations. These predictions can be tested in Pb+Pb collisions at the LHC, via event-by-event measurements of the di-jet asymmetry.

    hep-phhep-exnucl-thJHEP(2016)·11 citations
15. 15*

    Lepton number violation by heavy Majorana neutrino in $B$ decays

    Takehiko Asaka🇯🇵 · Hiroyuki Ishida🇹🇼

    Heavy Majorana neutrinos are predicted in addition to ordinary active neutrinos in the models with the seesaw mechanism. We investigate the lepton number violation (LNV) in $B$ decays induced by such a heavy neutrino $N$ with GeV-scale mass. Especially, we consider the decay channel $B^{+}\to {\mu }^{+}N\to {\mu }^{+}{\mu }^{+}{\pi }^{-}$ and derive the sensitivity limits on the mixing angle ${\Theta }_{\mu }$ by the future search experiments at Belle II and in $e^{+}{e}^{-}$ collisions at the Future Circular Collider (FCC-ee).

    hep-phhep-exPLB(2016)·38 citations
16. 16*

    Angular analyses of exclusive $\overline{B}\to X_J{\ell }_1{\ell }_2$ decays for spin $J\le 4$

    Biplab Dey🇮🇹

    As an update to our previous calculation for spin $J\le 2$, we present the angular moments for exclusive $\overline{B}\to X_J{\ell }_1{\ell }_2$, where ${\ell }_1$ is a charged massless lepton and ${\ell }_2$ is a charged or neutral massless lepton, and $X_J$ is a mesonic system with spin $J\le 4$. The expected applications include higher resonances in the $[K\pi ]$ system in ${\overline{B}}^0\to K^{-}{\pi }^{+}{\mu }^{-}{\mu }^{+}$ at LHCb in Run~II, and in the $[\pi \pi ]$ system for $\overline{B}\to \pi \pi {\ell }^{-}{\bar{\nu }}_{\ell }$ at Belle~II. For the $J\le 2$ case, we also provide a set of consistency relations among the measured moments observables and validate them against the latest measurements from LHCb.

    hep-phhep-exPRD(2017)·6 citations
17. 17*

    Triply heavy tetraquark states with the $QQ\bar{Q}\bar{q}$ configuration

    Kan Chen🇨🇳 · Xiang Liu🇨🇳 · Jing Wu🇨🇳 · Yan-Rui Liu🇨🇳 · Shi-Lin Zhu🇨🇳

    In the framework of the color-magnetic interaction, we systematically investigate the mass splittings of the $QQ\bar{Q}\bar{q}$ tetraquark states and estimated their rough masses in this work. These systems include the explicitly exotic states $cc\bar{b}\bar{q}$ and $bb\bar{c}\bar{q}$ and the hidden exotic states $cc\bar{c}\bar{q}$, $cb\bar{b}\bar{q}$, $bc\bar{c}\bar{q}$, and $bb\bar{b}\bar{q}$. If a state around the estimated mass region could be observed, its nature as a genuine tetraquark is favored. The strong decay patterns shown here will be helpful to the experimental search for these exotic states.

    hep-phEPJA(2017)·39 citations
18. 18*

    Subtraction of power counting breaking terms in chiral perturbation theory: spinless matter fields

    Meng-Lin Du🇩🇪 · Feng-Kun Guo🇨🇳 · Ulf-G. Meißner🇩🇪

    When matter fields are included in chiral perturbation theory, the nonvanishing mass in the chiral limit introduces a new energy scale so that the loop diagrams including such matter field propagators spoil the usual power counting. However, the power counting breaking terms can be absorbed into counterterms in the chiral Lagrangian. In this paper, we systematically derive these terms to leading one-loop order (next-to-next-to leading order in the chiral expansion) at once by calculating the generating functional using the path integral. They are then absorbed by counterterms in the next-to-leading order Lagrangian. The method can be extended to calculating power counting breaking terms for other matter fields.

    hep-phJHEP(2016)·15 citations
19. 19*

    Identifying a new particle with jet substructures

    Chengcheng Han🇯🇵 · Doojin Kim · Minho Kim · Kyoungchul Kong🇺🇸 · Sung Hak Lim🇰🇷 · Myeonghun Park🇰🇷

    We investigate a potential of measuring properties of a heavy resonance X, exploiting jet substructure techniques. Motivated by heavy higgs boson searches, we focus on the decays of X into a pair of (massive) electroweak gauge bosons. More specifically, we consider a hadronic Z boson, which makes it possible to determine properties of X at an earlier stage. For $m_X$ of O(1) TeV, two quarks from a Z boson would be captured as a "merged jet" in a significant fraction of events. The use of the merged jet enables us to consider a Z-induced jet as a reconstructed object without any combinatorial ambiguity. We apply a conventional jet substructure method to extract four-momenta of subjets from a merged jet. We find that jet substructure procedures may enhance features in some kinematic observables formed with subjets. Subjet momenta are fed into the matrix element associated with a given hypothesis on the nature of X, which is further processed to construct a matrix element method (MEM)-based observable. For both moderately and highly boosted Z bosons, we demonstrate that the MEM with current jet substructure techniques can be a very powerful discriminator in identifying the physics nature of X. We also discuss effects from choosing different jet sizes for merged jets and jet-grooming parameters upon the MEM analyses.

    hep-phhep-exJHEP(2017)·3 citations
20. 20*

    Coupling WW, ZZ unitarized amplitudes to $\gamma \gamma$ in the TeV region

    Rafael L. Delgado🇪🇸 · Antonio Dobado🇪🇸 · Felipe J. Llanes-Estrada🇪🇸

    We define and calculate helicity partial-wave amplitudes for processes linking the Electroweak Symmetry Breaking Sector (EWSBS) to $\gamma \gamma$, employing (to NLO) the Higgs-EFT (HEFT) extension of the Standard Model and the Equivalence Theorem, while neglecting all particle masses. The resulting amplitudes can be useful in the energy regime ($500\mathrm{GeV}-3\mathrm{TeV}$). We also deal with their unitarization so that resonances of the EWSBS can simultaneously be described in the $\gamma \gamma$ initial or final states. Our resulting amplitudes satisfy unitarity, perturbatively in $\alpha$, but for all $s$ values. In this way we improve on the HEFT that fails as interactions become stronger with growing $s$ and provide a natural framework for the decay of dynamically generated resonances into $WW$, $ZZ$ and $\gamma \gamma$ pairs.

    hep-phEPJC(2017)·17 citations
21. 21*

    Dimensional reduction of the Standard Model coupled to a new singlet scalar field

    Tomáš Brauner🇳🇴 · Tuomas V.I. Tenkanen🇫🇮 · Anders Tranberg🇳🇴 · Aleksi Vuorinen🇫🇮 · David J. Weir🇫🇮

    We derive an effective dimensionally reduced theory for the Standard Model augmented by a real singlet scalar. We treat the singlet as a superheavy field and integrate it out, leaving an effective theory involving only the Higgs and $\mathrm{SU}(2{)}_{\mathrm{L}}\times \mathrm{U}(1{)}_Y$ gauge fields, identical to the one studied previously for the Standard Model. This opens up the possibility of efficiently computing the order and strength of the electroweak phase transition, numerically and nonperturbatively, in this extension of the Standard Model. Understanding the phase diagram is crucial for models of electroweak baryogenesis and for studying the production of gravitational waves at thermal phase transitions.

    hep-phJHEP(2017)·75 citations
22. 22*

    Accommodation of the Dirac Phase in the Krauss-Nasri-Trodden Model

    Kingman Cheung🇹🇼 · Hiroyuki Ishida🇹🇼 · Hiroshi Okada🇹🇼

    We investigate one of the radiative models, Kraus-Nasri-Trodden model, with the maximal value of Dirac CP violating phase, $\delta$ is -\pi/2 (or equivalently 3\pi/2), which is preferred in not only recent long baseline experiments but also the global fit of neutrino oscillation data. We show that our predicted region of the \mu-e conversion rate can be searched in the future experiments without conflicting lepton-flavor violation and dark matter constraints.

    hep-ph11 citations
23. 23*

    The Asymptotic 3-Loop Heavy Flavor Corrections to the Charged Current Structure Functions $F_L^{W^{+}-W^{-}}(x,Q^2)$ and $F_2^{W^{+}-W^{-}}(x,Q^2)$

    A. Behring🇩🇪 · J. Blümlein🇩🇪 · G. Falcioni🇩🇪 · A. De Freitas🇩🇪 · A. von Manteuffel🇩🇪 · C. Schneider🇦🇹

    We calculate the massive Wilson coefficients for the heavy flavor contributions to the non-singlet charged current deep-inelastic scattering structure functions $F_L^{W^{+}}(x,Q^2)-F_L^{W^{-}}(x,Q^2)$ and $F_2^{W^{+}}(x,Q^2)-F_2^{W^{-}}(x,Q^2)$ in the asymptotic region $Q^2\gg m^2$ to 3-loop order in Quantum Chromodynamics (QCD) at general values of the Mellin variable $N$ and the momentum fraction $x$. Besides the heavy quark pair production, also the single heavy flavor excitation $s\to c$ contributes. Numerical results are presented for the charm quark contributions and consequences on the unpolarized Bjorken sum rule and Adler sum rule are discussed.

    hep-phhep-exPRD(2016)·29 citations
24. 24*

    Unbiased constraints on ultralight axion mass from dwarf spheroidal galaxies

    Alma X. Gonzalez-Morales🇲🇽 · David J. E. Marsh🇬🇧 · Jorge Peñarrubia🇬🇧 · L. Arturo Ureña-López🇲🇽

    It has been suggested that the internal dynamics of dwarf spheroidal galaxies (dSphs) can be used to test whether or not ultralight axions with $m_a\sim 10^{-22}\text{eV}$ are a preferred dark matter candidate. However, comparisons to theoretical predictions tend to be inconclusive for the simple reason that while most cosmological models consider only dark matter, one observes only baryons. Here we use realistic kinematic mock data catalogs of Milky Way dSph's to show that the "mass-anisotropy degeneracy" in the Jeans equations leads to biased bounds on the axion mass in galaxies with unknown dark matter halo profiles. In galaxies with multiple chemodynamical components this bias can be partly removed by modelling the mass enclosed within each subpopulation. However, analysis of the mock data reveals that the least-biased constraints on the axion mass result from fitting the luminosity-averaged velocity dispersion of the individual chemodynamical components directly. Applying our analysis to two dSph's with reported stellar subcomponents, Fornax and Sculptor, and assuming that the halo profile has not been acted on by baryons, yields core radii $r_c>1.5$ kpc and $r_c>1.2$ kpc respectively, and $m_a<0.4\times 10^{-22}\text{eV}$ at 97.5\% confidence. These bounds are in tension with the number of observed satellites derived from simple (but conservative) estimates of the subhalo mass function in Milky Way-like galaxies. We discuss how baryonic feedback might affect our results, and the impact of such a small axion mass on the growth of structures in the Universe.

    ↳ astro-ph.COastro-ph.GAhep-phMNRAS(2017)·142 citations
25. 25*

    The Lauricella Functions and Exact String Scattering Amplitudes

    Sheng-Hong Lai🇹🇼 · Jen-Chi Lee🇹🇼 · Yi Yang🇹🇼

    We discover that the 26D open bosonic string scattering amplitudes (SSA) of three tachyons and one arbitrary string state can be expressed in terms of the D-type Lauricella functions with associated SL(K+3,C) symmetry. As a result, SSA and symmetries or relations among SSA of different string states at various limits calculated previously can be rederived. These include the linear relations first conjectured by Gross [1-3] and later corrected and proved in [4-9] in the hard scattering limit, the recurrence relations in the Regge scattering limit with associated SL(5,C) symmetry [19-21] and the extended recurrence relations in the nonrelativistic scattering limit with associated SL(4,C) symmetry [24] discovered recently. Finally, as an application, we calculate a new recurrence relation of SSA which is valid for all energies.

    ↳ hep-thhep-phJHEP(2016)·17 citations
26. 26*

    Azimuthal asymmetries of charged hadrons produced in high-energy muon scattering off longitudinally polarised deuterons

    C. Adolph🇩🇪 · M. Aghasyan🇮🇹 · R. Akhunzyanov🇷🇺 · M.G. Alexeev🇮🇹 · G.D. Alexeev🇷🇺 · A. Amoroso🇮🇹 · V. Andrieux🇫🇷 · N.V. Anfimov🇷🇺 · V. Anosov🇷🇺 · K. Augsten🇨🇿 · W. Augustyniak🇵🇱 · A. Austregesilo🇩🇪 and 213 other authors

    Single hadron azimuthal asymmetries of positive and negative hadrons produced in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined using the 2006 COMPASS data and also combined all deuteron COMPASS data. For each hadron charge, the dependence of the azimuthal asymmetry on the hadron azimuthal angle $\varphi$ is obtained by means of a five-parameter fitting function that besides a $\varphi$-independent term includes four modulations predicted by theory: $\sin \varphi$, $\sin 2\varphi$, $\sin 3\varphi$ and $\cos \varphi$. The amplitudes of the five terms have been extracted, first, for the hadrons in the whole available kinematic region. In further fits, performed for hadrons from a restricted kinematic region, the $\varphi$-dependence is determined as a function of one of three variables (Bjorken-$x$, fractional energy of virtual photon taken by the outgoing hadron and hadron transverse momentum), while disregarding the others. Except the $\varphi$-independent term, all the modulation amplitudes are very small, and no clear kinematic dependence could be observed within experimental uncertainties.

    ↳ hep-exhep-phEPJC(2018)·14 citations
27. 27*

    Heavy flavor $R_{\text{AA}}$ and $v_n$ in event-by-event viscous relativistic hydrodynamics

    Caio A. G. Prado🇧🇷 · Jacquelyn Noronha-Hostler🇺🇸 · Mauro R. Cosentino🇧🇷 · Marcelo G. Munhoz🇧🇷 · Jorge Noronha🇧🇷 · Alexandre A. P. Suaide🇧🇷

    Recently it has been shown that a realistic description of the medium via event-by-event viscous hydrodynamics plays an important role in the long-standing $R_{\text{AA}}$ vs. $v_2$ puzzle at high $p_T$. In this proceedings we begin to extend this approach to the heavy flavor sector by investigating the effects of full event-by-event fluctuating hydrodynamic backgrounds on the nuclear suppression factor and $v_2\{2\}$ of heavy flavor mesons and non-photonic electrons at intermediate to high $p_T$. We also show results for $v_3\{2\}$ of $B^0$ and D${}^0$ for PbPb collisions at $\sqrt{s}=2.76$ TeV.

    ↳ nucl-thhep-phnucl-exJ.Phys.Conf.Ser.(2017)·7 citations
28. 28*

    Initial conditions for the Galileon dark energy

    Cristiano Germani (ICC, Universitat de Barcelona)🇪🇸

    Galileon models are among the most appealing candidates for Dark Energy. The reason is twofold: classically, they provide a tracking solution leading to an almost DeSitter space starting from very generic initial conditions in the deep radiation era. The second reason is the standard lore that Galileons are quantum mechanically stable. The latter property is certainly true in flat space-time, thanks to the non-renormalization theorems of galilean coupling constants. However, in a cosmological background, we show that quantum effects might dominate the classical trajectory. Assuming the radiation era to last at least up to the electroweak phase transition, the trajectory with initial conditions sitting on the tracker is ruled out. On the other hand, it is always possible to find a sub-space of initial conditions such that the dark energy solution approaches stably the tracker at late times. Fixing the value of initial conditions that best fit current data, and assuming that the galileon effective theory is valid up to the beginning of the radiation epoch, we found that the reheating temperature of the universe cannot be larger than $10^8\mathrm{GeV}$. Reversing the argument, if dark energy will turn out to be in form of Galileons, the bounds by EUCLID on the initial conditions for these models will also be a bound on the reheating temperature of our Universe.

    ↳ astro-ph.COgr-qchep-phhep-thPhys.Dark Univ.(2017)·10 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.