Fri·Jul 20, 2018Friday·July 20, 2018

1. 01*

   Direct detection of mirror helium dark matter in the CRESST-III experiment

   R. Foot🇦🇺

   Within the context of mirror dark matter, the dominant mass component of the Milky Way dark halo consists of mirror helium ions. Mirror helium can interact with ordinary matter if the kinetic mixing interaction exists. Mirror helium being rather light, $m\simeq 3.73$ GeV, generally produces sub-keV recoils in direct detection experiments. Recently, the CRESST-III experiment has began probing the sub-keV recoil energy region and is currently the most sensitive probe of such particles. We point out here that the small excess seen in the low energy recoil data obtained in the CRESST-III experiment is consistent with mirror helium scattering if the kinetic mixing parameter is around $ϵ\approx 5\times 10^{-10}$. This kinetic mixing strength lies within the estimated range favoured by small scale structure considerations.

   hep-phastro-ph.GA0 citations
2. 02*

   Analytic calculation of Energy-Energy Correlation in $e^{+}{e}^{-}$ annihilation at NLO

   Lance J. Dixon🇺🇸 · Ming-xing Luo🇨🇳 · Vladyslav Shtabovenko🇨🇳 · Tong-Zhi Yang🇨🇳 · Hua Xing Zhu🇨🇳

   We present the first fully analytic calculation of the Quantum Chromodynamics (QCD) event shape observable Energy-Energy Correlation in electron-positron annihilation at Next-To-Leading Order (NLO). This result sheds light on the analytic structure of the event shape observables beyond Leading Order (LO) and serves as a motivation to employ our methods in the investigation of other event shape observables that so far have not been calculated analytically.

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

   Parafermionic dark mater

   Teruyuki Kitabayashi🇯🇵 · Masaki Yasuè🇯🇵

   To discuss the possible contribution of parafermions to the dark matter abundance, we extend the Boltzmann equation for fermionic dark matter to include parafermions. Parafermions can accommodate $r$ particles per quantum state $(2\le r<\infty )$, where the parafermion of order $r=1$ is identical to the ordinary fermion. It is found that the parafermionic dark matter can be more abundant than the fermionic dark matter in the present universe.

   hep-phPRD(2018)·10 citations
4. 04*

   Model-independent constraints on the CKM matrix elements $|V_{tb}|$, $|V_{ts}|$ and $|V_{td}|$

   Wenxing Fang🇧🇪 · Barbara Clerbaux🇧🇪 · Andrea Giammanco🇧🇪 · Reza Goldouzian🇧🇪

   Single top quark production cross sections at hadron colliders are traditionally used to extract the modulus of the $V_{tb}$ element of the Cabibbo-Kobayashi-Maskawa matrix under the following assumption: $|V_{tb}|\gg |V_{td}|,|V_{ts}|$. For the first time, direct limits on $|V_{td}|$ and $|V_{ts}|$ are obtained using experimental data without the assumption of the unitarity of the CKM matrix. Limits on the $|V_{td}|$, $|V_{ts}|$ and $|V_{tb}|$ are extracted from differential measurements of single top quark cross sections in $t$-channel as a function of the rapidity and transverse momentum of the top quark and the light jet recoiling against the top quark. We have shown that the pseudorapidity of the forward jet in the single top production is one of the most powerful observables for discriminating between the $|V_{td}|$ and $|V_{tb}|$ events. We perform a global fit of top quark related CKM elements to experimental data from the LHC Runs I and II and Tevatron. Experimental data include inclusive and differential single top cross sections in $t$-channel, inclusive tW production cross section, and top quark branching ratio to b quark and W boson. We present bounds on $|V_{tb}|$, $|V_{ts}|$ and $|V_{td}|$ using current data and project the results for future LHC data sets corresponding to luminosities of 300 and 3000 \fb.

   hep-phJHEP(2019)·12 citations
5. 05*

   Same-sign trilepton signal for stop quark in the presence of sneutrino dark matter

   Dilip Kumar Ghosh🇮🇳 · Katri Huitu🇫🇮 · Subhadeep Mondal🇫🇮 · Manimala Mitra🇮🇳

   We have explored a minimal supersymmetric standard model scenario extended by one pair of gauge singlets per generation. In the model light neutrino masses and their mixings are generated via inverse seesaw mechanism. In such a scenario, a right-handed sneutrino can be the lightest supersymmetric particle and a cold Dark Matter (DM) candidate. If Casas-Ibarra parametrisation is imposed on the Dirac neutrino Yukawa coupling matrix ($Y_{\nu }$) to fit the neutrino oscillation data, the resulting $Y_{\nu }$ is highly constrained from the lepton flavor violating (LFV) decay constraints. The smallness of $Y_{\nu }$ requires the sneutrino DM to co-annihilate with other sparticle(s) in order to satisfy DM relic density constraint. We have studied sneutrino co-annihilation with wino and observed that this sneutrino-wino compressed parameter space gives rise to a novel same-sign trilepton signal for the stop quark, which is more effective than the conventional stop search channels in the present framework. We have shown that the choice of neutrino mass hierarchy strongly affects the signal event rate, making it easier to probe the scenario with inverted mass hierarchy.

   hep-phPRD(2019)·7 citations
6. 06*

   Top quark mass effects in HJ production at NLO

   Matthias Kerner🇩🇪

   We present predictions for gluon-fusion Higgs boson production in association with one jet at next-to-leading order in QCD. The calculation is performed retaining the full dependence on the top-quark mass. The two-loop integrals appearing in the virtual corrections are calculated numerically using the program SecDec. We show how a change of master integrals can improve the stability and runtime of the calculation. We study the Higgs boson transverse momentum distribution and compare our predictions with approximated results.

   hep-phhep-exPoS(2018)·0 citations
7. 07*

   Bottomonium suppression at RHIC and LHC

   Brandon Krouppa🇺🇸 · Alexander Rothkopf🇳🇴 · Michael Strickland🇺🇸

   The strong suppression of heavy quarkonia is a good indicator that one has generated a quark-gluon plasma (QGP) in an ultrarelativistic heavy ion collision. Recent advancements in first principles calculations of the heavy quark potential provide additional insight into this suppression and can be used to further pin down the in-medium properties of the QGP. Realistic 3+1d dissipative hydrodynamical models can be used to simulate the QGP and, with bottomonium as a probe, one can make inferences for the initial temperature of the QGP and other phenomenological parameters such as the shear viscosity to entropy density ratio. However, progressing to LHC $\sqrt{s_{NN}}=5.02$ TeV Pb-Pb collisions, one expects regeneration to have an increasingly important impact on the suppression observables. In this proceedings, we present a brief overview to set up the model and then provide model results for bottomonium suppression and regeneration, for ultrarelativistic heavy-ion collision experiments at RHIC and LHC.

   hep-phnucl-thNPA(2019)·11 citations
8. 08*

   Heavy quark mass effects in parton-to-kaon hadronization probabilities

   Manuel Epele🇦🇷 · Carlos García Canal🇦🇷 · Rodolfo Sassot🇦🇷

   We examine the relevance of the heavy quarks masses in the perturbative QCD description of hard interactions where charged kaons are produced in the final state. We extract a set of parton-to-kaon hadronization probabilities from a next to leading order QCD global analysis where a general mass variable flavor number scheme accounting for mass effects is implemented. We compare the results with those obtained in the massless approximation and also with those found in the case of final state pions. At variance with the very significant improvement found for the much more precise pion fragmentation phenomenology, the heavy quark mass dependent scheme improves mildly the overall description of current kaon production data. Nevertheless, the changes in the charm hadronization probability are noticeable.

   hep-phPLB(2019)·14 citations
9. 09*

   Structure of parton quasi-distributions and their moments

   Anatoly Radyushkin🇺🇸

   We discuss the structure of the parton quasi-distributions (quasi-PDFs) $Q(y,P_3)$ outside the "canonical" $-1\le y\le 1$ support region of the usual parton distribution functions (PDFs). Writing the $y^n$ moments of $Q(y,P_3)$ in terms of the combined $x^{n-2l}{k}_{\perp }^{2l}$-moments of the transverse momentum distribution (TMD) $\mathcal{F}(x,k_{\perp }^2)$, we establish a connection between the large-$|y|$ behavior of $Q(y,P_3)$ and large-$k_{\perp }^2$ behavior of $\mathcal{F}(x,k_{\perp }^2)$. In particular, we show that the $1/k_{\perp }^2$ hard tail of TMDs in QCD results in a slowly decreasing $\sim 1/|y|$ behavior of quasi-PDFs for large $|y|$ that produces infinite $y^n$ moments of $Q(y,P_3)$. We also relate the $\sim 1/|y|$ terms with the $\ln z_3^2$-singulariies of the Ioffe-time pseudo-distributions $\mathfrak{M}(\nu ,z_3^2)$. Converting the operator product expansion for $\mathfrak{M}(\nu ,z_3^2)$ into a matching relation between the quasi-PDF $Q(y,P_3)$ and the light-cone PDF $f(x,{\mu }^2)$, we demonstrate that there is no contradiction between the infinite values of the $y^n$ moments of $Q(y,P_3)$ and finite values of the $x^n$ moments of $f(x,{\mu }^2)$.

   hep-phhep-latPLB(2019)·58 citations
10. 10*

    Renormalization Scheme Ambiguities in the Models with More than One Coupling

    D.G.C. McKeon🇨🇦 · Chenguang Zhao🇨🇦

    The process of renormalization to eliminate divergences arising in quantum field theory is not uniquely defined; one can always perform a finite renormalization, rendering finite perturbative results ambiguous. The consequences of making such finite renormalizations have been examined in the case of there being one or two couplings. In this paper we consider how finite renormalizations can affect more general models in which there are more than two couplings. In particular, we consider the Standard Model in which there are essentially five couplings. We show that in this model (when neglecting all mass parameters) if we use mass independent renormalization, then the renormalization group beta-functions are not unique beyond one loop order, that it is not in general possible to eliminate all terms beyond certain order for all these beta-functions, but that for a physical process all contributions beyond one loop order can be subsumed into the beta-functions.

    hep-phCan.J.Phys.(2020)·4 citations
11. 11*

    Quasi-parton distribution functions: two-dimensional scalar and spinor QCD

    Xiangdong Ji🇨🇳 · Yizhuang Liu🇺🇸 · Ismail Zahed🇺🇸

    We construct the quasi-parton distributions of mesons for two-dimensional QCD with either scalar or spinor quarks using the $1/N_c$ expansion. We show that in the infinite momentum limit, the parton distribution function is recovered in both leading and sub-leading order in $1/N_c$.

    hep-phhep-thnucl-thPRD(2019)·33 citations
12. 12*

    Tri-Direct CP in the Littlest Seesaw Playground

    Gui-Jun Ding🇨🇳 · Stephen F. King🇬🇧 · Cai-Chang Li🇨🇳

    We discuss spontaneously broken CP symmetry in two right-handed neutrino models based on the idea of having a {\it different residual flavour symmetry}, together with a {\it different residual CP symmetry}, associated with each of the two right-handed neutrinos. The charged lepton sector also has a {\it different residual flavour symmetry}. In such a {\it tri-direct CP approach}, we show that the combination of the three residual flavour and two residual CP symmetries provides a new way of fixing the parameters. To illustrate the approach, we revisit the Littlest Seesaw (LSS) model based on $S_4$ and then propose new variants which have not so far appeared in the literature, with different predictions for each variant. We analyse numerically the predictions of the new variants, and then propose an explicit model which can realise one of the successful benchmark points, based on the atmospheric flavon vacuum alignment $(1,{\omega }^2,\omega )$ and the solar flavon vacuum alignment $(1,-7/2,-7/2)$.

    hep-phJHEP(2018)·22 citations
13. 13*

    DEFT: A program for operators in EFT

    Ben Gripaios🇬🇧 · Dave Sutherland🇺🇸

    We describe a Python-based computer program, DEFT, for manipulating operators in effective field theories (EFTs). In its current incarnation, DEFT can be applied to 4-dimensional, Poincaré invariant theories with gauge group $SU(3)\times SU(2)\times U(1)$, such as the Standard Model (SM), but a variety of extensions (e.g. to lower dimensions or to an arbitrary product of unitary gauge groups) are conceptually straightforward. Amongst other features, the program is able to: (i) check whether an input list of Lagrangian operators (of a given dimension in the EFT expansion) is a basis for the space of operators contributing to S-matrix elements, once redundancies (such as Fierz-Pauli identities, integration by parts, and equations of motion) are taken into account; (ii) generate such a basis (where possible) from an input algorithm; (iii) carry out a change of basis. We describe applications to the SM (where we carry out a number of non-trivial cross-checks) and extensions thereof, and outline how the program may be of use in precision tests of the SM and in the ongoing search for new physics at the LHC and elsewhere. The code and instructions can be downloaded from http://web.physics.ucsb.edu/~dwsuth/DEFT/.

    hep-phJHEP(2019)·59 citations
14. 14*

    Transverse momentum dependent distributions with jets

    Daniel Gutierrez-Reyes🇪🇸 · Ignazio Scimemi🇪🇸 · Wouter J. Waalewijn🇳🇱 · Lorenzo Zoppi🇳🇱

    We investigate the use of jets to measure transverse momentum dependent distributions (TMDs). The example we use to present our framework is the dijet momentum decorrelation at lepton colliders. Translating this momentum decorrelation into an angle $\theta \ll 1$, we analyze the factorization of the cross section for the cases $\theta \gg R$, $\theta \sim R$ and $\theta \ll R$, where $R$ is the jet radius. Critically, for the Winner-Take-All axis, the jet TMD has the same double-scale renormalization group evolution as TMD fragmentation functions for all radii $R$. TMD fragmentation functions in factorization theorems may then simply be replaced by the jet TMDs we calculate, and all ingredients to perform the resummation to next-to-next-to-leading logarithmic accuracy are available. Our approach also applies to semi-inclusive deep inelastic scattering (SIDIS), where a jet instead of a hadron is measured in the final state, and we find a clean method to probe the intrinsic transverse momentum of quarks and gluons in the proton that is less sensitive to final-state nonperturbative effects.

    hep-phnucl-thPRL(2018)·81 citations
15. 15*

    Unrestored Electroweak Symmetry

    Patrick Meade🇺🇸 · Harikrishnan Ramani🇺🇸

    The commonly assumed cosmological history of our universe is that at early-times and high-temperatures the universe went through an ElectroWeak Phase Transition (EWPT). Assuming an EWPT, and depending on its strength, there are many implications for baryogenesis, gravitational waves, and the evolution of the universe in general. However, it is not true that all spontaneously broken symmetries at zero-temperature are restored at high-temperature. In particular the idea of "inverse symmetry breaking" has long been established in scalar theories with evidence from both perturbative and lattice calculations. In this letter we demonstrate that with a simple extension of the SM it is possible that the ElectroWeak (EW) symmetry was always broken or only temporarily passed through a symmetry restored phase. These novel phase histories have many cosmological and collider implications that we discuss. The model presented here serves as a useful benchmark comparison for future attempts to discern the phase of our universe at $T\gtrsim$ a few GeV.

    hep-phastro-ph.COPRL(2019)·85 citations
16. 16*

    The Ultraviolet Landscape of Two-Higgs Doublet Models

    Manuel E. Krauss🇩🇪 · Toby Opferkuch🇩🇪 · Florian Staub🇩🇪

    We study the predictions of generic ultraviolet completions of two-Higgs doublet models. We assume that at the matching scale between the two-Higgs doublet model and a ultraviolet complete theory -- which can be anywhere between the TeV and the Planck scale -- arbitrary but perturbative values for the quartic couplings are present. We evaluate the couplings down from the matching scale to the weak scale and study the predictions for the scalar mass spectrum. In particular, we show the importance of radiative corrections which are essential for both an accurate Higgs mass calculation as well as determining the stability of the electroweak vacuum. We study the relation between the mass splitting of the heavy Higgs states and the size of the quartic couplings at the matching scale, finding that only a small class of models exhibit a sizeable mass splitting between the heavy scalars at the weak scale. Moreover, we find a clear correlation between the maximal size of the couplings and the considered matching scale.

    hep-phEPJC(2018)·16 citations
17. 17*

    A Proposal to Detect Dark Matter Using Axionic Topological Antiferromagnets

    David J. E. Marsh🇩🇪 · Kin-Chung Fong🇺🇸 · Erik W. Lentz🇩🇪 · Libor Šmejkal🇩🇪 · Mazhar N. Ali🇩🇪

    Antiferromagnetically doped topological insulators (A-TI) are among the candidates to host dynamical axion fields and axion-polaritons; weakly interacting quasiparticles that are analogous to the dark axion, a long sought after candidate dark matter particle. Here we demonstrate that using the axion quasiparticle antiferromagnetic resonance in A-TI's in conjunction with low-noise methods of detecting THz photons presents a viable route to detect axion dark matter with mass 0.7 to 3.5 meV, a range currently inaccessible to other dark matter detection experiments and proposals. The benefits of this method at high frequency are the tunability of the resonance with applied magnetic field, and the use of A-TI samples with volumes much larger than 1 mm${}^3$.

    hep-phcond-mat.mes-hallcond-mat.str-elhep-ex+1PRL(2019)·159 citations
18. 18*

    Penetrating probes: Jets and photons in a non-equilibrium quark-gluon plasma

    Sigtryggur Hauksson🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦

    We employ new field-theoretical tools to study photons and jets in a non-equilibrium quark-gluon plasma. Jet broadening and photon emission takes place through radiation which is suppressed by repeated and coherent interaction with the medium. We analyze this physics in an anisotropic plasma such as is created in the early stages of heavy-ion collisions. The anisotropy introduces an angular dependence in radiation and reduces its overall rate. This can affect phenomenological predictions of the rapidity dependence and angular flow of jets and photons.

    ↳ nucl-thhep-phNPA(2019)·3 citations
19. 19*

    CNO Solar Neutrinos in Next-Generation Dark Matter Experiments

    Jayden L. Newstead🇺🇸 · Louis E. Strigari🇺🇸 · Rafael F. Lang🇺🇸

    We study the prospects for measuring the low-energy components of the solar neutrino flux in future direct dark matter detection experiments. We show that for a depletion of ${}^{136}$Xe by a factor of 100 relative to its natural abundance, and an extension to electron recoil energies of $\sim$ MeV, future xenon experiments with exposure $\sim 200$ ton-yr can detect the CNO component of the solar neutrino flux at $\sim 3\sigma$ significance. A CNO detection will provide important insight into metallicity of the solar interior. Precise measurement of low-energy solar neutrinos, including as $pp$, ${}^7$Be, and $pep$ components, will further improve constraints on the "neutrino luminosity" of the Sun, thereby providing constraints on alternative sources of energy production. We find that a measurement of $L_{\nu }/L_{\odot }$ of order one percent is possible with the above exposure, improving on current bounds from a global analysis of solar neutrino data by a factor of about seven.

    ↳ astro-ph.SRhep-phphysics.ins-detPRD(2019)·35 citations
20. 20*

    Axion Cosmology with Early Matter Domination

    Ann E. Nelson🇺🇸 · Huangyu Xiao🇺🇸

    The default assumption of early universe cosmology is that the postinflationary universe was radiation dominated until it was about 47000 years old. Direct evidence for the radiation dominated epoch extends back until nucleosynthesis, which began during the first second. However there are theoretical reasons to prefer a period of earlier matter domination, prior to nucleosynthesis, e.g. due to late decaying massive particles needed to explain baryogenesis. Axion cosmology is quantitatively affected by an early period of matter domination, with a different axion mass range preferred and greater inhomogeneity produced on small scales. In this work we show that such increased inhomogeneity can lead to the formation of axion miniclusters in axion parameter ranges that are different from those usually assumed. If the reheating temperature is below $58$ MeV, axion miniclusters can form even if the axion field is present during inflation and has been previously homogenized. The upper bound on the typical initial axion minicluster mass is raised from $10^{-10}{M}_{\odot }$ to $10^{-7}{M}_{\odot }$, where $M_{\odot }$ is a solar mass. These results may have consequences for indirect detection of axion miniclusters, and could conceivably probe the thermal history of the universe before nucleosynthesis.

    ↳ astro-ph.COhep-phPRD(2018)·84 citations
21. 21*

    Small system studies: A theory overview

    Michael Strickland🇺🇸

    There is now a substantial body of evidence that a deconfined quark-gluon plasma is created in ultrarelativistic collisions of heavy nuclei. Some key observables which are used to gauge the production of the quark-gluon plasma are the hadronic spectra and multiplicities across many species, azimuthal anisotropies in the production of various hadrons, jet quenching, photon/dilepton production, and heavy quarkonium suppression. A key question in the study of the quark-gluon plasma is what happens to these observables as one changes the system size. In particular, it is very interesting to study collisions of `small systems' such as pp, dA, pA, and $e^{+}{e}^{-}$ since naively one does not expect to produce a QGP in these cases. One of the surprises from such studies was the existence of sizable azimuthal anisotropies in the hadron spectra in the highest multiplicity classes, which led to speculations that one can generate a QGP in such relatively rare events. This interpretation, however, is complicated by the fact that there can be multiple sources of azimuthal anisotropy. I will discuss our current understanding of the different sources of azimuthal anisotropies and the multiplicity windows in which each mechanism is expected to dominate. I will also provide a critical discussion of the reliability of hydrodynamic models applied to small systems. Finally, I will briefly discuss jet quenching and heavy quarkonium suppression in small systems and discuss whether or not these observables show any indication of the production of a small QGP droplet.

    ↳ nucl-thhep-phNPA(2019)·40 citations
22. 22*

    Gauge-ready formulation of cosmological perturbations in scalar-vector-tensor theories

    Lavinia Heisenberg🇨🇭 · Ryotaro Kase🇯🇵 · Shinji Tsujikawa🇯🇵

    In scalar-vector-tensor (SVT) theories with parity invariance, we perform a gauge-ready formulation of cosmological perturbations on the flat Friedmann-Lemaître-Robertson-Walker (FLRW) background by taking into account a matter perfect fluid. We derive the second-order action of scalar perturbations and resulting linear perturbation equations of motion without fixing any gauge conditions. Depending on physical problems at hand, most convenient gauges can be chosen to study the development of inhomogeneities in the presence of scalar and vector fields coupled to gravity. This versatile framework, which encompasses Horndeski and generalized Proca theories as special cases, is applicable to a wide variety of cosmological phenomena including nonsingular cosmology, inflation, and dark energy. By deriving conditions for the absence of ghost and Laplacian instabilities in several different gauges, we show that, unlike Horndeski theories, it is possible to evade no-go arguments for the absence of stable nonsingular bouncing/genesis solutions in both generalized Proca and SVT theories. We also apply our framework to the case in which scalar and vector fields are responsible for dark energy and find that the separation of observables relevant to the evolution of matter perturbations into tensor, vector, and scalar sectors is transparent in the unitary gauge. Unlike the flat gauge chosen in the literature, this result is convenient to confront SVT theories with observations associated with the cosmic growth history.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2018)·18 citations
23. 23*

    Foreground Biases on Primordial Non-Gaussianity Measurements from the CMB Temperature Bispectrum: Implications for Planck and Beyond

    J. Colin Hill🇺🇸

    The cosmic microwave background (CMB) temperature bispectrum is currently the most precise tool for constraining primordial non-Gaussianity (NG). The Planck temperature data tightly constrain the amplitude of local-type NG: $f_{\mathrm{NL}}^{\mathrm{loc}}=2.5\pm 5.7$. Here, we compute previously-neglected foreground biases in temperature-based $f_{\mathrm{NL}}^{\mathrm{loc}}$ measurements, due to the integrated Sachs-Wolfe (ISW) effect, gravitational lensing, the thermal and kinematic Sunyaev-Zel'dovich effects, and the cosmic infrared background. While standard analyses already subtract a significant bias on $f_{\mathrm{NL}}^{\mathrm{loc}}$ due to the ISW-lensing bispectrum, many other secondary anisotropy terms are present in the temperature bispectrum. We compute the dominant biases on $f_{\mathrm{NL}}^{\mathrm{loc}}$ arising from these signals. Most of the biases are non-blackbody, and are thus reduced by multifrequency component separation methods; however, recent analyses have found that extragalactic foregrounds are present at non-negligible levels in the Planck component-separated maps. Moreover, the Planck FFP8 simulations do not include the foreground correlations that generate these biases. We compute the biases for individual frequencies; some are comparable to the statistical error bar on $f_{\mathrm{NL}}^{\mathrm{loc}}$, even for the main CMB channels (100, 143, and 217 GHz). For future experiments, they greatly exceed the statistical error (considering temperature only). Alternatively, the foreground contributions can be marginalized over, but this leads to a non-negligible increase in the error bar on $f_{\mathrm{NL}}^{\mathrm{loc}}$. A full assessment will require calculations in tandem with component separation, ideally using simulations. We also compute these biases for equilateral and orthogonal NG, finding large effects for the latter. We conclude that the search for primordial NG using Planck data may not yet be over.

    ↳ astro-ph.COhep-phhep-thPRD(2018)·47 citations
24. 24*

    Search for "Electroweakinos" with the ATLAS Detector at the LHC

    Alexander Mann (for the ATLAS Collaboration)🇩🇪

    Supersymmetry is one of the most popular extensions of the Standard Model of particle physics, as it offers solutions to several shortcomings of the Standard Model. Natural supersymmetric models favor masses for the new particles which are predicted by supersymmetry in the range of hundreds of GeV, well within the reach of the Large Hadron Collider at CERN. If squarks and gluinos are much heavier, the production of charginos and neutralinos may be the dominant production mode for supersymmetric particles. These proceedings present results from new searches for the production of charginos and neutralinos, focusing on the recent paper by the ATLAS collaboration that summarizes and extends the searches for the electroweak production of supersymmetric particles using data from Run-1 of the LHC.

    ↳ hep-exhep-phProceedings of the 3rd Conference on Larg…·0 citations
25. 25*

    Variations on the Dirac string

    Brad Cownden🇨🇦 · Andrew R. Frey🇨🇦

    Dirac's original solution of the nontrivial Bianchi identity for magnetic monopoles [Dirac 1948], which redefines the fieldstrength along the Dirac string, diagonalizes the gauge and monopole degrees of freedom. We provide a variant of the Dirac string, which we motivate through a formal expansion of the Bianchi identity. We show how to use our variant prescription to study monopole electrodynamics without reference to a dual potential and provide some applications.

    ↳ hep-thhep-phPRD(2018)·1 citation
26. 26*

    Prospects for a measurement of the $W$ boson mass in the all-jets final state at hadron colliders

    Marat Freytsis🇺🇸 · Philip Harris🇺🇸 · Andreas Hinzmann🇩🇪 · Ian Moult🇺🇸 · Nhan Tran🇺🇸 · Caterina Vernieri🇺🇸

    Precise measurements of the mass of the $W$ boson are important to test the overall consistency of the Standard Model of particle physics. The current best measurements of the $W$ boson mass come from single production measurements at hadron colliders in its decay mode to a lepton (electron or muon) and a neutrino and pair production of $W$ bosons at lepton colliders, where also the decay mode of the $W$ boson to hadrons has been considered. In this study, prospects for a measurement of the $W$ boson mass in the all-jet final state at hadron colliders are presented. The feasibility of this measurement takes advantage of numerous recent developments in the field of jet substructure. Compared to other methods for measuring the $W$ mass, a measurement in the all-jets final state would be complementary in methodology and have systematic uncertainties orthogonal to previous measurements. We have estimated the main experimental and theoretical uncertainties affecting a measurement in the all-jet final state. With new trigger strategies, a statistical uncertainty for the measurement of the mass difference between the $Z$ and $W$ bosons of 30 MeV could be reached with HL-LHC data corresponding to 3000 fb${}^{-1}$ of integrated luminosity. However, in order to reach that precision, the current understanding of non-perturbative contributions to the invariant mass of $W\to q{\bar{q}}^{\prime }$ and $Z\to b\bar{b}$ jets will need to be refined. Similar strategies will also allow the reach for generic boosted resonances searches in hadronic channels to be extended.

    ↳ hep-exhep-phJHEP(2019)·10 citations
27. 27*

    Back-Reaction of Super-Hubble Cosmological Perturbations Beyond Perturbation Theory

    Robert Brandenberger🇨🇦 · Leila L. Graef🇧🇷 · Giovanni Marozzi🇮🇹 · Gian Paolo Vacca🇮🇹

    We discuss the effect of super-Hubble cosmological fluctuations on the locally measured Hubble expansion rate. We consider a large bare cosmological constant in the early universe in the presence of scalar field matter (the dominant matter component), which would lead to a scale-invariant primordial spectrum of cosmological fluctuations. Using the leading order gradient expansion we show that the expansion rate measured by a (secondary) clock field which is not comoving with the dominant matter component obtains a negative contribution from infrared fluctuations, a contribution whose absolute value increases in time. This is the same effect which a decreasing cosmological constant would produce. This supports the conclusion that infrared fluctuations lead to a dynamical relaxation of the cosmological constant. Our analysis does not make use of any perturbative expansion in the amplitude of the inhomogeneities.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2018)·52 citations
28. 28*

    Prescaling in a far-from-equilibrium Bose gas

    Christian-Marcel Schmied🇩🇪 · Aleksandr N. Mikheev🇩🇪 · Thomas Gasenzer🇩🇪

    Non-equilibrium conditions give rise to classes of universally evolving configurations of quantum-many body systems at non-thermal fixed points. While the fixed point and thus full scaling in space and time is generically reached at very long evolution times, we propose that systems can show prescaling much earlier in time, in particular, on experimentally accessible time scales. During the prescaling evolution, some well-measurable properties of spatial correlations already scale with the universal exponents of the fixed point while others still show scaling violations. Prescaling is characterized by the evolution obeying conservation laws associated with the remaining symmetry which also defines the universality class of the asymptotically reached non-thermal fixed point. Here we consider $N=3$ species of spatially uniform three-dimensional Bose gases, with identical inter- and intra-species interactions. During prescaling, the full $U(N)$ symmetry of the model is broken to $U(N-1)$ while the conserved transport, reflecting explicit and emerging symmetries, leads to the buildup of rescaling quasicondensate distributions.

    ↳ cond-mat.quant-gascond-mat.stat-mechhep-phPRL(2019)·42 citations
29. 29*

    The Maximum Angular-Diameter Distance in Cosmology

    Fulvio Melia🇺🇸 · Manoj K. Yennapureddy🇺🇸

    Unlike other observational signatures in cosmology, the angular-diameter distance d_A(z) uniquely reaches a maximum (at z_max) and then shrinks to zero towards the big bang. The location of this turning point depends sensitively on the model, but has been difficult to measure. In this paper, we estimate and use z_max inferred from quasar cores: (1) by employing a sample of 140 objects yielding a much reduced dispersion due to pre-constrained limits on their spectral index and luminosity, (2) by reconstructing d_A(z) using Gaussian processes, and (3) comparing the predictions of seven different cosmologies and showing that the measured value of z_max can effectively discriminate between them. We find that z_max=1.70 +\- 0.20---an important new probe of the Universe's geometry. The most strongly favoured model is R_h=ct, followed by Planck LCDM. Several others, including Milne, Einstein-de Sitter and Static tired light are strongly rejected. According to these results, the R_h=ct universe, which predicts z_max=1.718, has a ~92.8% probability of being the correct cosmology. For consistency, we also carry out model selection based on d_A(z) itself. This test confirms that R_h=ct and Planck LCDM are among the few models that account for angular-size data better than those that are disfavoured by z_max. The d_A(z) comparison, however, is less discerning than that with z_max, due to the additional free parameter, H_0. We find that H_0=63.4 +\- 1.2 km/s/Mpc for R_h=ct, and 69.9 +\- 1.5 km/s/Mpc for LCDM. Both are consistent with previously measured values in each model, though they differ from each other by over 4 sigma. In contrast, model selection based on z_max is independent of H_0.

    ↳ astro-ph.COastro-ph.HEhep-phMNRAS(2018)·13 citations
30. 30*

    Upsilon states in magnetized nuclear matter

    Amal Jahan C.S. · Shivam Kesarwani🇮🇳 · Sushruth Reddy P.🇮🇳 · Nikhil Dhale🇮🇳 · Amruta Mishra🇮🇳

    The mass modifications of the bottomonium states (${\rm Y}(NS)$,$N=1,2,3,4$ and ${\rm Y}(1D)$) in magnetized nuclear matter are studied using chiral effective model. The in-medium masses are calculated from the medium modification of the scalar dilaton field in the chiral effective model, which simulates the gluon condensates of QCD. The strengths of the wave functions (assumed to be harmonic oscillator wave functions) denoted by the parameter, $\beta$, of the ${\rm Y}(NS)$, $N=1,2,3,4$, are fitted from their observed decay widths to $e^{+}{e}^{-}$. The decay width for the channel, ${\rm Y}(1D)\to e^{+}{e}^{-}$ %, which has not yet been observed experimentally, has been predicted in the present work, by using the value of the parameter, $\beta$ for ${\rm Y}(1D)$, interpolated from the $\beta$ versus mass relation, for the upsilon states. The effects of the isospin asymmetry of the nuclear medium on the masses of the upsilon states are investigated and are observed to be large for high densities. This should have observable consequences at the asymmetric heavy ion collisions at the Compressed baryonic matter (CBM) experiments at FAIR, GSI as well as at SPS, CERN. The study of the bottomonium states at CBM will however require access to higher energies than the energy regime planned at present. The effects of magnetic field on the masses of bottomonium states in nuclear matter are studied in the present work. These masses are investigated including the anomalous magnetic moments (AMM) of the nucleons, and compared to the results when the AMMs of nucleons are not taken into account. The effects of magnetic field as well as isospin asymmetry on the upsilon masses are obserevd to be large at high densities.

    ↳ nucl-thhep-ph16 citations
31. 31*

    Geometrically confined thermal field theory: Finite size corrections and phase transitions

    Sylvain Mogliacci🇿🇦 · Isobel Kolbé🇿🇦 · W. A. Horowitz🇿🇦

    Motivated by the recent shocking results from RHIC and LHC that show quark-gluon plasma signatures in small systems, we study a simple model of a massless, noninteracting scalar field confined with Dirichlet boundary conditions. We use this system to investigate the finite size corrections to thermal field theoretically derived quantities compared to the usual Stefan-Boltzmann limit of an ideal gas not confined in any direction. Two equivalent expressions with different numerical convergence properties are found for the free energy in $D$ rectilinear spacetime dimensions with $c\le D-1$ spatial dimensions of finite extent. We find that the First Law of Thermodynamics generalizes such that the pressure depends on direction but that the Third Law is respected. For systems with finite dimension(s) but infinite volumes, such as a field constrained between two parallel plates or a rectangular tube, the relative fluctuations in energy are zero, and hence the canonical and microcanonical ensembles are equivalent. We present precise numerical results for the free energy, total internal energy, pressure, entropy, and heat capacity of our field between parallel plates, in a tube, and in finite volume boxes of various sizes in 4 spacetime dimensions. For temperatures and system sizes relevant for heavy ion phenomenology, we find large deviations from the Stefan-Boltzmann limit for these quantities, especially for the pressure. Further investigation of an isolated system of fields constrained between parallel plates reveals a divergent isoenergetic compressibility at a critical length $L_c\sim 1/T$. We have thus discovered a new second order phase transition via a first principles calculation, a transition that is driven by the size of the system.

    ↳ hep-thcond-mat.quant-gascond-mat.stat-mechhep-ph+1PRD(2020)·27 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.