Fri·Jul 7, 2017Friday·July 7, 2017

1. 01*

   The Higgsploding Universe

   Valentin V. Khoze🇬🇧 · Michael Spannowsky🇬🇧

   Higgsplosion is a dynamical mechanism that introduces an exponential suppression of quantum fluctuations beyond the Higgsplosion energy scale E_* and further guarantees perturbative unitarity in multi-Higgs production processes. By calculating the Higgsplosion scale for spin 0, 1/2, 1 and 2 particles at leading order, we argue that Higgsplosion regulates all n-point functions, thereby embedding the Standard Model of particle physics and its extensions into an asymptotically safe theory. There are no Landau poles and the Higgs self-coupling stays positive. Asymptotic safety is of particular interest for theories of particle physics that include quantum gravity. We argue that in a Hippsloding theory one cannot probe shorter and shorter length scales by increasing the energy of the collision beyond the Higgsplosion energy and there is a minimal length set by r_* ~ 1/E_* that can be probed. We further show that Higgsplosion in consistent and not in conflict with models of inflation and the existence of axions. There is also a possibility of testing Higgsplosion experimentally at future high energy experiments.

   hep-phastro-ph.HEhep-thPRD(2017)·24 citations
2. 02*

   Towards small-$x$ resummed parton distribution functions

   Luca Rottoli🇬🇧 · Marco Bonvini🇮🇹

   We present preliminary results for fits of parton distribution functions (PDFs) which include the resummation of small-$x$ logarithms at NLLx accuracy, performed in the NNPDF framework. We observe an improvement in the description of DIS data at small values of Bjorken $x$ when resummation effects are included. The improvement is more marked when comparing NNLO+NLLx fits to NNLO ones, and is particularly noticeable for small-$x$ and small-$Q^2$ HERA inclusive structure functions. The main effect of the resummation is an enhancement of the gluon and singlet PDFs at small-$x$, which persists at high scales.

   hep-phhep-exPoS(2018)·4 citations
3. 03*

   Medium response in JEWEL and its impact on jet shape observables in heavy ion collisions

   Raghav Kunnawalkam Elayavalli🇺🇸 · Korinna Christine Zapp🇨🇭

   Realistic modeling of medium-jet interactions in heavy ion collisions is becoming increasingly important to successfully predict jet structure and shape observables. In JEWEL, all partons belonging to the parton showers initiated by hard scattered partons undergo collisions with thermal partons from the medium, leading to both elastic and radiative energy loss. The recoiling medium partons carry away energy and momentum from the jet. Since the thermal component of these recoils' momenta is part of the soft background activity, comparison with data requires the implementation of a subtraction procedure. We present two independent procedures through which background subtraction can be performed and discuss the impact of the medium recoil on jet shape observables. Keeping track of the medium response significantly improves the JEWEL description of jet shape measurements.

   hep-phJHEP(2017)·203 citations
4. 04*

   Inevitable emergence of composite gauge bosons

   Mahiko Suzuki🇺🇸

   A simple theorem is proved: When a gauge-invariant local field theory is written in terms of matter fields alone, a composite gauge boson or bosons must be formed dynamically. The theorem results from the fact that the Noether current vanishes in such theories. The proof is carried out by use of the charge-field algebra at equal time in the Heisenberg picture together with the well-established analyticity of the form factor of the current. While there is no need of diagram calculation for the proof, we demonstrate in the leading 1/N expansion of the existing models what the theorem means in diagrams and how the composite gauge boson emerges.

   hep-phPRD(2017)·17 citations
5. 05*

   Quantum tomography for collider physics: Illustrations with lepton pair production

   John C. Martens🇺🇸 · John P. Ralston🇺🇸 · J.D. Tapia Takaki🇺🇸

   Quantum tomography is a method to experimentally extract all that is observable about a quantum mechanical system. We introduce quantum tomography to collider physics with the illustration of the angular distribution of lepton pairs. The tomographic method bypasses much of the field-theoretic formalism to concentrate on what can be observed with experimental data, and how to characterize the data. We provide a practical, experimentally-driven guide to model-independent analysis using density matrices at every step. Comparison with traditional methods of analyzing angular correlations of inclusive reactions finds many advantages in the tomographic method, which include manifest Lorentz covariance, direct incorporation of positivity constraints, exhaustively complete polarization information, and new invariants free from frame conventions. For example, experimental data can determine the $entanglement$ $entropy$ of the production process, which is a model-independent invariant that measures the degree of coherence of the subprocess. We give reproducible numerical examples and provide a supplemental standalone computer code that implements the procedure. We also highlight a property of $complex$ $positivity$ that guarantees in a least-squares type fit that a local minimum of a ${\chi }^2$ statistic will be a global minimum: There are no isolated local minima. This property with an automated implementation of positivity promises to mitigate issues relating to multiple minima and convention-dependence that have been problematic in previous work on angular distributions.

   hep-phhep-exEPJC(2018)·35 citations
6. 06*

   FMFT: Fully Massive Four-loop Tadpoles

   Andrey Pikelner🇩🇪

   We present FMFT - a package written in FORM that evaluates four-loop fully massive tadpole Feynman diagrams. It is a successor of the MATAD package that has been successfully used to calculate many renormalization group functions at three-loop order in a wide range of quantum field theories especially in the Standard Model. We describe an internal structure of the package and provide some examples of its usage.

   hep-phComput.Phys.Commun.(2018)·16 citations
7. 07*

   Searching for heavy sterile neutrinos in kaon decays

   C. Weiland🇬🇧

   We present here a study of the impact of a heavy neutrino (or heavy neutral lepton) on leptonic and semileptonic kaon decays. We used a simplified model consisting of 3 light neutrinos responsible for neutrino oscillations and a heavy sterile neutrino. We found that it can lead to large deviations from the Standard Model predictions for leptonic decays, in conflict with experimental measurements of $K_{e2}$ and the lepton universality test $R_K$. This allows to derive new constraints on the leptonic mixing for heavy sterile neutrinos. No tension was found when considering the semileptonic decays. Finally, we point out the potential of the decay $K_L\to \nu \nu$ as a clear signature of physics beyond the Standard Model.

   hep-phhep-ex0 citations
8. 08*

   Establishing low-lying doubly charmed baryons

   Hua-Xing Chen🇨🇳 · Qiang Mao🇨🇳 · Wei Chen🇨🇳 · Xiang Liu🇨🇳 · Shi-Lin Zhu🇨🇳

   We systematically study the $S$-wave doubly charmed baryons using the method of QCD sum rules. Our results suggest that the ${\Xi }_{cc}^{++}$ recently observed by LHCb can be well identified as the $S$-wave ${\Xi }_{cc}$ state of $J^P=1/2^{+}$. We study its relevant ${\Omega }_{cc}$ state, whose mass is predicted to be around 3.7 GeV. We also systematically study the $P$-wave doubly charmed baryons, whose masses are predicted to be around 4.1 GeV. Especially, there can be several excited doubly charmed baryons in this energy region, and we suggest to search for them in order to study the fine structure of the strong interaction.

   hep-phhep-exhep-latPRD(2017)·61 citations
9. 09*

   Pseudoscalar couplings in $t\bar{t}H$ production at NLO+NLL accuracy

   Alessandro Broggio🇩🇪 · Andrea Ferroglia🇺🇸 · Miguel C. N. Fiolhais🇺🇸 · Antonio Onofre🇵🇹

   We study the production of a Higgs boson in association to a top-antitop pair at the Large Hadron Collider. We show how precise predictions for the differential distributions with respect to the transverse momentum of the Higgs boson, to the invariant mass of the top-antitop-Higgs system and to the invariant mass of the top-antitop pair can provide useful information on the possible presence of a pseudoscalar component in the coupling of the top quark with the Higgs boson. We evaluate the production of a top-antitop pair and a Higgs boson to next-to-leading order in fixed order perturbation theory and we carry out the resummation of soft emission corrections to next-to-leading-logarithmic accuracy for the LHC operating at a center of mass energy of $13$ TeV. We discuss how the shape of these distributions can be employed experimentally, making a physics case for the kinematic reconstruction of dilepton channels.

   hep-phPRD(2017)·16 citations
10. 10*

    Regimes of the Pomeron and its Intrinsic Entropy

    Edward Shuryak🇺🇸 · Ismail Zahed🇺🇸

    We suggest that the perturbative and non-perturbative descriptions of the Pomeron can be viewed as complementary descriptions of different phases in the Pomeron phase diagram, with a phase boundary where the proper description of the produced systems are "string balls". Their intrinsic entropy is calculated and turned out to be the same, as the recently reported perturbative entanglement entropy. The distribution of large multiplicities stemming from the string balls is also wide, with its moments close to those reported for hadrons in $pp$ collisions at the LHC. At low-x, the quantum string is so entangled that sufficiently weak string self-attraction can cause it to turn to a string ball dual to a black hole. We suggest that low-x saturation occurs when the density of wee-strings reaches the Bekenstein bound, with a proton size that freezes with increasing rapidity. Some of these observations maybe checked at the future eIC.

    hep-phhep-thnucl-thAnnals Phys.(2018)·26 citations
11. 11*

    Noncommutative scalar fields in compact spaces: quantisation and implications

    Mir Mehedi Faruk🇧🇩 · Mishkat Al Alvi🇧🇩 · Wasif Ahmed🇧🇩 · Md Muktadir Rahman🇧🇩 · Arup Barua Apu🇺🇸

    In this paper we consider a two component scalar field theory, with noncommutativity in its conjugate momentum space. We quantize such a theory in a compact space with the help of dressing transformations and we reveal a significant effect of introducing such noncommutativity as the splitting of the energy levels of each individual mode that constitutes the whole system. We further compute the thermal partition function exactly with predicted deformed dispersion relations from noncommutative theories and compare the results with usual results. It is found that thermodynamic quantities in noncommutative models, irrespective of whether the model is more deformed in infrared/UV region, show deviation from standard results in high temperature region.

    ↳ hep-thcond-mat.stat-mechgr-qchep-ph+2PTEP(2017)·2 citations
12. 12*

    The Charm of Theoretical Physics (1958-1993)

    Luciano Maiani🇮🇹 · Luisa Bonolis🇩🇪

    Personal recollections on theoretical particle physics in the years when the Standard Theory was formed. In the background, the remarkable development of Italian theoretical physics in the second part of the last century, with great personalities like Bruno Touschek, Raoul Gatto, Nicola Cabibbo and their schools.

    ↳ physics.hist-phhep-exhep-phEur.Phys.J.H(2017)·7 citations
13. 13*

    A new helioseismic constraint on a cosmic-time variation of G

    Alfio Bonanno🇮🇹 · Hans-Erich Fröhlich🇩🇪

    Helioseismology can provide strong constraints on the evolution of Newton's constant over cosmic time. We make use of the best possible estimate of 8640 days of low-$\ell$ BISON data, corrected for the solar cycle variation, to obtain a new constraint on an evolving gravitational constant. In particular, by means of a Bayesian analysis we conclude that ${\dot{G}/G}_{\mathrm{today}}=(1.25\pm 0.30)\times 10^{-13}{\mathrm{yr}}^{-1}$. Our result, a 4-$\sigma$ effect, is more than one order of magnitude stronger than previous constraints obtained with helioseismology. We also take into account possible systematic effects by considering the theoretical uncertainties on the efficiency of the proton-proton $(pp)$ fusion cross-section. We show that models with variable $G$ significantly outclass models with no secular variation of $G$, viz by a Bayes factor exceeding 30.

    ↳ astro-ph.SRhep-phApJL(2020)·14 citations
14. 14*

    Approximate degeneracy of $J=1$ spatial correlators in high temperature QCD

    C. Rohrhofer🇦🇹 · Y. Aoki🇯🇵 · G. Cossu🇬🇧 · H. Fukaya🇯🇵 · L. Ya. Glozman🇦🇹 · S. Hashimoto🇯🇵 · C. B. Lang🇦🇹 · S. Prelovsek🇸🇮

    We study spatial isovector meson correlators in $N_f=2$ QCD with dynamical domain-wall fermions on $32^3\times 8$ lattices at temperatures $T=220-380$ MeV. We measure the correlators of spin-one ($J=1$) operators including vector, axial-vector, tensor and axial-tensor. Restoration of chiral $U(1{)}_A$ and $SU(2{)}_L\times SU(2{)}_R$ symmetries of QCD implies degeneracies in vector--axial-vector ($SU(2{)}_L\times SU(2{)}_R$) and tensor--axial-tensor ($U(1{)}_A$) pairs, which are indeed observed at temperatures above $T_c$. Moreover, we observe an approximate degeneracy of all $J=1$ correlators with increasing temperature. This approximate degeneracy suggests emergent $SU(2{)}_{CS}$ and $SU(4)$ symmeries at high temperatures, that mix left- and right-handed quarks.

    ↳ hep-lathep-phhep-thPRD(2017)·49 citations
15. 15*

    Pulsar TeV Halos Explain the TeV Excess Observed by Milagro

    Tim Linden🇺🇸 · Benjamin J. Buckman🇺🇸

    Milagro observations have found bright, diffuse TeV emission concentrated along the galactic plane of the Milky Way. The intensity and spectrum of this emission is difficult to explain with current models where gamma-ray production is dominated by hadronic mechanisms, and has been named the "TeV excess". We show that TeV emission from pulsars naturally explains this excess. In particular, recent observations have detected "TeV halos" surrounding pulsars that are either nearby or particularly luminous. Here, we show that the full population of Milky Way pulsars will produce diffuse TeV emission concentrated along the Milky Way plane. The total gamma-ray flux from TeV halos is expected to exceed the hadronic gamma-ray flux at energies above ~500 GeV. Moreover, the spectrum and intensity of TeV halo emission naturally matches the TeV excess. If this scenario is common to all galaxies, it will decrease the contribution of star-forming galaxies to the IceCube neutrino flux. Finally, we show that upcoming HAWC observations will resolve a significant fraction of the TeV excess into individual TeV halos, conclusively confirming, or ruling out, this model.

    ↳ astro-ph.HEastro-ph.GAhep-phPRL(2018)·63 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.