Fri·Aug 26, 2016Friday·August 26, 2016

1. 01*

   Nonrelativistic Short-Distance Completions of a Naturally Light Higgs

   Kevin T. Grosvenor🇩🇰 · Petr Horava🇺🇸 · Christopher J. Mogni🇺🇸 · Ziqi Yan🇺🇸

   Nonrelativistic scalar field theories can exhibit a natural cascading hierarchy of scales, protected by a hierarchy of polynomial shift symmetries. Using a simple model, we argue that a high-energy cross-over to such nonrelativistic behavior naturally leads to light scalars, and thus represents a useful ingredient for technically natural resolutions of scalar mass hierarchies, perhaps even the Higgs mass hierarchy puzzle.

   hep-phhep-lathep-thPLB(2025)·5 citations
2. 02*

   Alignment without Decoupling: the Portal to Light Dark Matter in the MSSM

   Stefano Profumo🇺🇸 · Tim Stefaniak🇺🇸

   We study light, thermal neutralino dark matter in the sub-GeV to 65 GeV mass range in the Minimal Supersymmetric extension of the Standard Model (MSSM). We consider realizations of the limit of alignment without decoupling in the Higgs sector where the heavier CP-even Higgs impersonates the observed Higgs state at 125 GeV, while the lighter CP-even Higgs is the mediator of dark matter annihilation. We single out three distinct and novel possibilities for light dark matter: (i) a neutralino with mass around half the light Higgs mass, in the sub-GeV to 30 GeV mass range; (ii) a neutralino with a mass around half the pseudoscalar Higgs boson mass, in our examples around 60 to 65 GeV; (iii) a very light neutralino with mass around the light Higgs mass, pair-annihilating to Higgs pairs. We discuss the implications of all these possibilities for indirect and direct dark matter detection experiments, and we demonstrate that all scenarios will be tested by next generation direct detection experiments. We also emphasize that the unique Higgs phenomenology of these scenarios warrants a dedicated search program at the LHC.

   hep-phastro-ph.HEhep-exPRD(2016)·16 citations
3. 03*

   A Radiative Model of Quark Masses with Binary Tetrahedral Symmetry

   Alexander Natale🇰🇷

   A radiative model of quark and lepton masses utilizing the binary tetrahedral ($T^{\prime }$) flavor symmetry, or horizontal symmetry, is proposed which produces the first two generation of quark masses through their interactions with vector-like quarks that carry charges under an additional $U(1)$. By softly-breaking the $T^{\prime }$ to a residual $Z_4$ through the vector-like quark masses, a CKM mixing angle close to the Cabibbo angle is produced. In order to generate the cobimaximal neutrino oscillation pattern (${\theta }_{13}\ne 0,{\theta }_{23}=\pi /4,{\delta }_{CP}=\pm \pi /2$) and protect the horizontal symmetry from arbitrary corrections in the lepton sector, there are automatically two stabilizing symmetries in the dark sector. Several benchmark cases where the correct relic density is achieved in a multi-component DM scenario, as well as the potential collider signatures of the vector-like quarks are discussed.

   hep-phNPB(2017)·5 citations
4. 04*

   Stopped nucleons in configuration space

   Andrzej Bialas🇵🇱 · Adam Bzdak🇵🇱 · Volker Koch🇺🇸

   In this note, using the colour string model, we study the configuration space distribution of stopped nucleons in heavy-ion collisions. We find that the stopped nucleons from the target and the projectile end up separated from each other by the distance increasing with the collision energy. In consequence, for the center of mass energies larger than 6 or 10 GeV (depending on the details of the model) it appears that the system created is not in thermal and chemical equilibrium, and the net baryon density reached is likely not much higher than that already present in the colliding nuclei.

   hep-phhep-exnucl-thActa Phys.Polon.B(2018)·26 citations
5. 05*

   QCD Factorization for $B\to \pi \pi \ell \nu$ Decays at Large Dipion Masses

   Philipp Böer (Siegen U)🇩🇪 · Thorsten Feldmann (Siegen U)🇩🇪 · Danny van Dyk (Siegen U and Zurich U)🇩🇪

   We introduce a factorization formula for semi-leptonic $b\to u$ transitions in the exclusive decay mode $B^{-}\to {\pi }^{+}{\pi }^{-}{\ell }^{-}{\bar{\nu }}_{\ell }$ in the limit of large pion energies and large dipion invariant mass. One contribution can be described in terms of a universal $B\to \pi$ form factor and the convolution of a short-distance kernel $T^{\mathrm{I}}$ with the respective light-cone distribution amplitudes (LCDAs) of the positively charged pion. The second contribution, at leading power, completely factorizes, with a short-distance kernel $T^{\mathrm{II}}$ convoluted with the leading-twist LCDAs for both pions and the $B$-meson. We calculate the leading contributions to the short-distance kernels $T^{\mathrm{I}}$ and $T^{\mathrm{II}}$ in fixed-order perturbation theory, and discuss the approximate relations among the resulting $B\to \pi \pi$ partial-wave form factors. Our results provide useful theoretical constraints for phenomenological models that aim to analyze the complete $B\to \pi \pi \ell \nu$ phase space.

   hep-phJHEP(2017)·35 citations
6. 06*

   Semi-leptonic Production of $D_{sJ}(3040)$ and $D_J(3000)$ in $B_s$ and $B$ Decays

   Si-chen Li🇨🇳 · Yue Jiang🇨🇳 · Tian-hong Wang🇨🇳 · Qiang Li🇨🇳 · Zhi-hui Wang🇨🇳 · Guo-Li Wang🇨🇳

   In this paper, we study the productions of the newly detected states $D_{sJ}(3040)$ and $D_J(3000)$ observed by BABAR Collaboration and LHCb Collaboration. We assume these states to be the $D_s(2P)$ and $D(2P)$ states with the quantum number $J^P=1^{+}$ in our work. The results of improved Bethe-Salpeter method indicate that the semi-leptonic decays via $B_s$ and $B$ into $D_{sJ}(3040)$ and $D_J(3000)$ have considerable branching ratios, for example, Br(${\bar{B}}_s^0\to D{}_{sJ}^{+}(3040)e^{-}\bar{\nu }{}_e$)=$5.79\times 10^{-4}$, Br(${\bar{B}}^0\to D_J^{+}(3000)e^{-}\bar{\nu }{}_e$)=$2.63\times 10^{-4}$, which shows that these semi-leptonic decays can be accessible in experiments.

   hep-phMod.Phys.Lett.A(2016)·6 citations
7. 07*

   A new $G$-parity violating amplitude in the $J/\psi$ decay?

   R. Baldini Ferroli🇮🇹 · F. De Mori🇮🇹 · M. Destefanis🇮🇹 · M. Maggiora🇮🇹 · S. Pacetti🇮🇹 · L. Yan🇨🇳 · M. Bertani🇮🇹 · A. Calcaterra🇮🇹 · G. Felici🇮🇹 · P. Patteri🇮🇹 · Y. D. Wang🇩🇪 · A. Zallo🇮🇹 and 16 other authors

   The $J/\psi$ meson has negative $G$-parity so that, in the limit of isospin conservation, its decay into ${\pi }^{+}{\pi }^{-}$ should be purely electromagnetic. However, the measured branching fraction $\mathcal{B}(J/\psi \to {\pi }^{+}{\pi }^{-})$ exceeds by more than 3.9 standard deviations the expectation computed according to BaBar data on the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ cross section. The possibility that the two-gluon plus one-photon decay mechanism is not suppressed by $G$-parity conservation is discussed, even by considering other multi-pion decay channels. As also obtained by phenomenological computation, such a decay mechanism could be responsible for the observed discrepancy. Finally, we notice that the BESIII experiment, having the potential to perform an accurate measurement of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ cross section in the 3 GeV energy region, can definitely prove or disprove this strong $G$-parity-violating mechanism by confirming or confuting the BaBar data.

   hep-phPRD(2017)·2 citations
8. 08*

   Is Electroweak Symmetry Breaking Still Natural in the MSSM?

   Bhaskar Dutta🇺🇸 · Yukihiro Mimura🇹🇼

   The absence of any signal of supersymmetry (SUSY) at the LHC has raised the SUSY particle mass scale compared to $Z$ boson mass $M_Z$. We investigate the naturalness of the electroweak symmetry breaking after considering radiative symmetry breaking along with 125 GeV Higgs mass. We find that the important quantity to measure the naturalness of the hierarchy between the SUSY scale and $M_Z$ is the separation between the radiative symmetry breaking scale, i.e., where $m_{H_u}^2+{\mu }^2$ turns negative for large $\tan \beta$ case ($\mu$ is the Higgsino mass and $m_{H_u}$ is the SUSY breaking up-type Higgs boson mass) and the average stop mass. Using this measure, one can show that the electroweak symmetry breaking can be natural even if $\mu$ is large contrary to the prevailing claim that $\mu$ is needed to be small to maintain the naturalness.

   hep-ph2 citations
9. 09*

   Charting the future frontier(s) of particle production

   Jan Rafelski🇺🇸

   This short note describes the long collaborative effort between Arizona and Kraków, showing some of the key strangeness signatures of quark-gluon plasma. It further presents an annotated catalog of foundational questions defining the research frontiers which I believe can be addressed in the foreseeable future in the context of relativistic heavy ion collision experiments. The list includes topics that are specific to the field, and ventures towards the known-to-be-unknown that may have a better chance with ions as compared to elementary interactions.

   hep-phnucl-thphysics.hist-phActa Phys.Polon.B(2016)·0 citations
10. 10*

    Collapse of Axion Stars

    Joshua Eby🇺🇸 · Madelyn Leembruggen🇺🇸 · Peter Suranyi🇺🇸 · L.C.R. Wijewardhana🇺🇸

    Axion stars, gravitationally bound states of low-energy axion particles, have a maximum mass allowed by gravitational stability. Weakly bound states obtaining this maximum mass have sufficiently large radii such that they are dilute, and as a result, they are well described by a leading-order expansion of the axion potential. Heavier states are susceptible to gravitational collapse. Inclusion of higher-order interactions, present in the full potential, can give qualitatively different results in the analysis of collapsing heavy states, as compared to the leading-order expansion. In this work, we find that collapsing axion stars are stabilized by repulsive interactions present in the full potential, providing evidence that such objects do not form black holes. In the last moments of collapse, the binding energy of the axion star grows rapidly, and we provide evidence that a large amount of its energy is lost through rapid emission of relativistic axions.

    ↳ astro-ph.COhep-phhep-thJHEP(2016)·142 citations
11. 11*

    Waiting for the W and the Higgs

    M.J.Tannenbaum🇺🇸

    The search for the left-handed $W^{\pm }$ bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.

    ↳ physics.hist-phhep-exhep-phEur.Phys.J.H(2016)·3 citations
12. 12*

    The Weak Gravity Conjecture and Effective Field Theory

    Prashant Saraswat🇺🇸

    The Weak Gravity Conjecture (WGC) is a proposed constraint on theories with gauge fields and gravity, requiring the existence of light charged particles and/or imposing an upper bound on the field theory cutoff $\Lambda$. If taken as a consistency requirement for effective field theories (EFTs), it rules out possibilities for model-building including some models of inflation. I demonstrate simple models which satisfy all forms of the WGC, but which through Higgsing of the original gauge fields produce low-energy EFTs with gauge forces that badly violate the WGC. These models illustrate specific loopholes in arguments that motivate the WGC from a bottom-up perspective; for example the arguments based on magnetic monopoles are evaded when the magnetic confinement that occurs in a Higgs phase is accounted for. This indicates that the WGC should not be taken as a veto on EFTs, even if it turns out to be a robust property of UV quantum gravity theories. However, if the latter is true then parametric violation of the WGC at low energy comes at the cost of non-minimal field content in the UV. I propose that only a very weak constraint is applicable to EFTs, $\Lambda \lesssim {\left(-\log g\right)}^{-1/2}{M}_{\text{pl}}$ where $g$ is the gauge coupling, motivated by entropy bounds. Remarkably, EFTs produced by Higgsing a theory that satisfies the WGC can saturate but not violate this bound.

    ↳ hep-thgr-qchep-phPRD(2017)·111 citations
13. 13*

    Constraints on Large Extra Dimensions from the MINOS Experiment

    P. Adamson🇺🇸 · I. Anghel🇺🇸 · A. Aurisano🇺🇸 · G. Barr🇬🇧 · M. Bishai🇺🇸 · A. Blake🇬🇧 · G. J. Bock🇺🇸 · D. Bogert🇺🇸 · S. V. Cao🇺🇸 · T. J. Carroll🇺🇸 · C. M. Castromonte🇧🇷 · R. Chen🇬🇧 and 108 other authors

    We report new constraints on the size of large extra dimensions from data collected by the MINOS experiment between 2005 and 2012. Our analysis employs a model in which sterile neutrinos arise as Kaluza-Klein states in large extra dimensions and thus modify the neutrino oscillation probabilities due to mixing between active and sterile neutrino states. Using Fermilab's NuMI beam exposure of $10.56\times 10^{20}$ protons-on-target, we combine muon neutrino charged current and neutral current data sets from the Near and Far Detectors and observe no evidence for deviations from standard three-flavor neutrino oscillations. The ratios of reconstructed energy spectra in the two detectors constrain the size of large extra dimensions to be smaller than $0.45\mu \text{m}$ at 90% C.L. in the limit of a vanishing lightest active neutrino mass. Stronger limits are obtained for non-vanishing masses.

    ↳ hep-exhep-phPRD(2016)·30 citations
14. 14*

    Remarks on the effects of the Gribov copies on the infrared behavior of higher dimensional Yang-Mills theory

    M. S. Guimaraes🇧🇷 · A. D. Pereira🇧🇷 · S. P. Sorella🇧🇷

    In this paper, we discuss non-perturbative infrared features of Yang-Mills theory in Euclidean space-time dimensions greater than four in the Landau gauge and within the Refined Gribov-Zwanziger framework, which enables us to take into account the existence of gauge copies by restricting the domain of integration in the path integral to the Gribov region. Evidences for a decoupling/massive solution for the gluon propagator in higher dimensions are provided. This behavior is strengthened the bigger the dimension is. Further, we show that, by a dimensional reduction of the Refined Gribov-Zwanziger action from five to four dimensions, a non-perturbative coupling between the inverse of the Faddeev-Popov operator and the scalar field corresponding to the fifth component of the gauge field naturally arises, being in agreement with the recently proposed mechanism \cite{Capri:2014bsa} to generalize the Refined Gribov-Zwanziger construction to the matter sector.

    ↳ hep-thhep-lathep-phPRD(2016)·11 citations
15. 15*

    Consequences of a strong phase transition in the dense matter equation of state for the rotational evolution of neutron stars

    M. Bejger🇵🇱 · D. Blaschke🇷🇺 · P. Haensel🇵🇱 · J. L. Zdunik🇵🇱 · M. Fortin🇵🇱

    We explore the implications of a strong first-order phase transition region in the dense matter equation of state in the interiors of rotating neutron stars, and the resulting creation of two disjoint families of neutron-star configurations (the so-called high-mass twins). We numerically obtained rotating, axisymmetric, and stationary stellar configurations in the framework of general relativity, and studied their global parameters and stability. The instability induced by the equation of state divides stable neutron star configurations into two disjoint families: neutron stars (second family) and hybrid stars (third family), with an overlapping region in mass, the high-mass twin-star region. These two regions are divided by an instability strip. Its existence has interesting astrophysical consequences for rotating neutron stars. We note that it provides a natural explanation for the rotational frequency cutoff in the observed distribution of neutron star spins, and for the apparent lack of back-bending in pulsar timing. It also straightforwardly enables a substantial energy release in a mini-collapse to another neutron-star configuration (core quake), or to a black hole.

    ↳ astro-ph.HEastro-ph.SRhep-phnucl-thAstron.Astrophys.(2017)·49 citations
16. 16*

    Complete ${\alpha }^{6}m$ corrections to the ground state of H${}_2$

    Mariusz Puchalski🇵🇱 · Jacek Komasa · Pawel Czachorowski · Krzysztof Pachucki🇵🇱

    We perform the calculation of all relativistic and quantum electrodynamic corrections of the order of ${\alpha }^{6}m$ to the ground electronic state of a hydrogen molecule and present improved results for the dissociation and the fundamental transitions energies. These results open the window for the high-precision spectroscopy of H${}_2$ and related low-energy tests of fundamental interactions.

    ↳ physics.chem-phhep-phPRL(2016)·27 citations
17. 17*

    Why $\Xi (1690)$ and $\Xi (2120)$ are so narrow?

    K. P. Khemchandani🇧🇷 · A. Martínez Torres🇧🇷 · A. Hosaka🇯🇵 · H. Nagahiro🇯🇵 · F. S. Navarra🇧🇷 · M. Nielsen🇧🇷

    The $\Xi$ baryons are expected to be naturally narrower as compared to their nonstrange and strange counterparts since they have only one light quark and, thus, their decay involves producing either a light meson and doubly strange baryon or both meson and baryon with strangeness which involves, relatively, more energy. In fact, some $\Xi$'s have full widths of the order of even 10-20 MeV when, in principle, they have a large phase space to decay to some open channels. Such is the case of $\Xi (1690)$, for which the width has been found to be of the order of 10 MeV in the latest {\it BABAR} and BELLE data. In this manuscript we study why some $\Xi$'s are so narrow. Based on a coupled channel calculation of the pseudoscalar meson-baryon and vector meson-baryon systems with chiral and hidden local symmetry Lagrangians, we find that the answer lies in the intricate hadron dynamics. We find that the known mass, width, spin-parity and branching ratios of $\Xi (1690)$ can be naturally explained in terms of coupled channel meson-baryon dynamics. We find another narrow resonance which can be related to $\Xi (2120)$. We also look for exotic states ${\Xi }^{+}$ and ${\Xi }^{--}$ but find none. In addition we provide the cross sections for $\bar{K}\Lambda ,\bar{K}\Sigma \to \pi \Xi$ which can be useful for understanding the enhanced yield of $\Xi$ reported in recent studies of heavy ion collisions.

    ↳ nucl-thhep-phPRD(2018)·33 citations
18. 18*

    Dwarf spheroidal J-factors without priors: A likelihood-based analysis for indirect dark matter searches

    A. Chiappo🇸🇪 · J. Cohen-Tanugi🇫🇷 · J. Conrad🇸🇪 · L. E. Strigari🇺🇸 · B. Anderson🇸🇪 · M.A. Sanchez-Conde🇸🇪

    Line-of-sight integrals of the squared density, commonly called the J-factor, are essential for inferring dark matter annihilation signals. The J-factors of dark matter-dominated dwarf spheroidal satellite galaxies (dSphs) have typically been derived using Bayesian techniques, which for small data samples implies that a choice of priors constitutes a non-negligible systematic uncertainty. Here we report the development of a new fully frequentist approach to construct the profile likelihood of the J-factor. Using stellar kinematic data from several classical and ultra-faint dSphs, we derive the maximum likelihood value for the J-factor and its confidence intervals. We validate this method, in particular its bias and coverage, using simulated data from the Gaia Challenge. We find that the method possesses good statistical properties. The J-factors and their uncertainties are generally in good agreement with the Bayesian-derived values, with the largest deviations restricted to the systems with the smallest kinematic datasets. We discuss improvements, extensions, and future applications of this technique.

    ↳ astro-ph.COastro-ph.GAastro-ph.HEhep-phMNRAS(2017)·33 citations
19. 19*

    Constraints on hadronic models in extensive air showers with the Pierre Auger Observatory

    J. Espadanal (for the Pierre Auger Collaboration)🇵🇹

    Extensive air showers initiated by ultra-high energy cosmic rays are sensitive to the details of hadronic interactions models, so we present the main results obtained using the data of the Pierre Auger Observatory. The depth at which the maximum of the electromagnetic development takes place is the most sensitive parameter to infer the nature of the cosmic rays. However, the hadronic models cannot describe consistently the maximum and the muon measurements at energies higher than those reached at the LHC.

    ↳ astro-ph.HEhep-exhep-phEPJ Web Conf.(2016)·2 citations
20. 20*

    Overscreened Kondo effect, (color) superconductivity and Shiba states in Dirac metals and quark matter

    Takuya Kanazawa🇯🇵 · Shun Uchino🇯🇵

    We study the interplay between the Kondo effect and (color) superconductivity in doped Dirac metals with magnetic impurities and in quark matter with colorful impurities. We first point out that the overscreened Kondo effect arises in the normal state of these systems. Next the (color) superconducting gap is incorporated as a mean field and the phase diagram for a varying gap and temperature is constructed nonperturbatively. A rich phase structure emerges from a competition of effects unique to a multichannel system. The Kondo-screened phase is shown to disappear for a sufficiently large gap. Peculiarity of quark matter due to the confining property of non-Abelian gauge fields is noted. We also investigate the spectrum of sub-gap excited states, called Shiba states. Based on a model calculation and physical reasoning we predict that, as the coupling of the impurity to the bulk is increased, there will be more than one quantum phase transition due to level crossing among overscreened states.

    ↳ cond-mat.str-elcond-mat.supr-conhep-phnucl-thPRD(2016)·24 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.