HEP Phenomenology·hep-ph

Wed·Dec 21, 2016Wednesday·December 21, 2016

48 papers—31 primary·17 cross-listed·reconstructed*

01*
Prospect for observing a light charged Higgs through the decay $H^{+} \to c b ˉ + c . c .$ at the LHeC
J. Hernández-Sánchez🇲🇽 · O. Flores-Sánchez🇲🇽 · C. G. Honorato🇲🇽 · S. Moretti🇬🇧 · S. Rosado🇲🇽
We study the production and decay of a light charged Higgs boson at the future Large Hadron electron Collider (LHeC) in the framework of the Two Higgs Doublet Type III, assuming a four-zero texture in the Yukawa matrices and a general Higgs potential. We analyze the charge current production processes $e^{-} p \to ν_{e} q H^{+}$ considering the signature $H^{+} \to c b ˉ + c . c .$ of the final state. We take this signature and we compare it to the irreducible background from Standard Model (SM) interactions. We consider scenarios of the model which are consistent with current experimental data from Higgs and flavor physics.
hep-phPoS(2017)·8 citations
02*
Supersymmetry with Dark Matter is still natural
Melissa van Beekveld🇳🇱 · Wim Beenakker🇳🇱 · Sascha Caron🇳🇱 · Ruud Peeters🇳🇱 · Roberto Ruiz de Austri🇪🇸
We identify the parameter regions of the phenomenological minimal supersymmetric standard model (pMSSM) with the minimal possible fine-tuning. We show that the fine-tuning of the pMSSM is not large, nor under pressure by LHC searches. Low sbottom, stop and gluino masses turn out to be less relevant for low fine-tuning than commonly assumed. We show a link between low fine-tuning and the dark matter relic density. Fine-tuning arguments point to models with a dark matter candidate yielding the correct dark matter relic density: a bino-higgsino particle with a mass of $35 - 155$ GeV. Some of these candidates are compatible with recent hints seen in astrophysics experiments such as Fermi-LAT and AMS-02. We argue that upcoming direct search experiments, such as XENON1T, will test all of the most natural solutions in the next few years due to the sensitivity of these experiments on the spin-dependent WIMP-nucleon cross section.
hep-phPRD(2017)·38 citations
03*
Dark Matter and Collider Studies in the Left-Right Symmetric Model with Vector-Like Leptons
Sahar Bahrami🇨🇦 · Mariana Frank🇨🇦 · Dilip Kumar Ghosh🇮🇳 · Nivedita Ghosh🇮🇳 · Ipsita Saha🇮🇹
In the context of a left-right symmetric model, we introduce one full generation of vectorlike lepton doublets (both left and right-handed) together with their mirror doublets. We show that the lightest vectorlike neutrino in the model is right-handed, and can serve as the dark matter candidate. We find that the relic density, as well as the direct and indirect DM detection bounds, are satisfied for a large range of the parameter space of the model. In accordance with the parameter space, we then explore the possibility of detecting signals of the model at both the LHC and the ILC, in the pair production of the associated vectorlike charged leptons which decay into final states including dark matter. A comprehensive analysis of signal and backgrounds shows that the signals at the ILC, especially with polarized beams are likely to be visible for light vectorlike leptons, even with low luminosity, rendering our model highly predictable and experimentally testable.
hep-phPRD(2017)·37 citations
04*
Probing light mediators at ultra-low threshold energies with coherent elastic neutrino-nucleus scattering
James B. Dent🇺🇸 · Bhaskar Dutta🇺🇸 · Shu Liao🇺🇸 · Jayden L. Newstead🇺🇸 · Louis E. Strigari🇺🇸 · Joel W. Walker🇺🇸
Light neutral mediators, with mass $≲ 1$ GeV, are common features of extensions to the Standard Model (SM). Current astrophysical and terrestrial experiments have constrained the model parameter space, and planned experiments around the world promise continued improvement in sensitivity. In this paper we study the prospects for probing light neutral mediators using terrestrial stopped pion and reactor sources in combination with ultra-low threshold nuclear and electron recoil detectors. We show that the coherent neutrino-nucleus and neutrino-electron scattering channels provide complementary sensitivity to light mediators. With low threshold detectors, we show that most stringent bounds on models arise from the nuclear scattering process, improving upon previous bounds from electron scattering of solar neutrinos by nearly an order of magnitude for mediator masses $≳ 0.1$ GeV.
hep-phPRD(2017)·79 citations
05*
The triple Higgs coupling: A new probe of low-scale seesaw models
Julien Baglio🇩🇪 · Cédric Weiland🇬🇧
The measure of the triple Higgs coupling is one of the major goals of the high-luminosity run of the CERN Large Hadron Collider (HL-LHC) as well as the future colliders, either leptonic such as the International Linear Collider (ILC) or hadronic such as the 100 TeV Future Circular Collider in hadron-hadron mode (FCC-hh). We have recently proposed this observable as a test of neutrino mass generating mechanisms in a regime where heavy sterile neutrino masses are hard to be probed otherwise. We present in this article a study of the one-loop corrected triple Higgs coupling in the inverse seesaw model, taking into account all relevant constraints on the model. This is the first study of the impact on the triple Higgs coupling of heavy neutrinos in a realistic, renormalizable neutrino mass model. We obtain deviations from the Standard Model as large as to $\sim + 30%$ that are at the current limit of the HL-LHC sensitivity, but would be clearly visible at the ILC or at the FCC-hh.
hep-phJHEP(2017)·25 citations
06*
A Clockwork WIMP
Thomas Hambye🇧🇪 · Daniele Teresi🇧🇪 · Michel H.G. Tytgat🇧🇪
We embed a thermal dark matter (DM) candidate within the clockwork framework. This mechanism allows to stabilize the DM particle over cosmological time because it suppresses its decay into Standard Model (SM) particles. At the same time, pair annihilations are unsuppressed, so that the relic density is set by the usual freeze-out of the DM particle from the thermal bath. The slow decay of the DM candidate is induced by "clockwork" particles that can be quite light (rather than at some GUT or Planck scale) and could be searched for at current or future colliders. According to the scenario considered, the very same particles also mediate the annihilation process, thus providing a connection between DM annihilation and DM decay, and fixing the mass scale of the clockwork states, otherwise unconstrained, to be in the TeV range or lighter. We then show how this setup can minimally emerge from the deconstruction of an extra dimension in flat spacetime. Finally, we argue that the clockwork mechanism that we consider could induce Majorana neutrino masses, with a seesaw scale of order TeV or less and Yukawa couplings of order unity.
hep-phhep-thJHEP(2017)·53 citations
07*
Gottfried sum rule in QCD NS analysis of DIS fixed target data
A.V. Kotikov🇷🇺 · V.G. Krivokhizhin🇷🇺 · B.G. Shaikhatdenov🇷🇺
Deep inelastic scattering data on $F_{2}$ structure function obtained in the fixed-target experiments were analysed in the valence quark approximation with a next-to-next-to-leading-order accuracy. Parton distribution functions are parametrized by using information from the Gottfried sum rule. The strong coupling constant is found to be $α_{s} (M_{Z}^{2}) = 0.1180 \pm 0.0020 \mbox (t o t a l e x p . er r or)$ , which coincides very well with the average world value $α_{s}^{PDG} (M_{Z}^{2}) = 0.1181 \pm 0.0013$ updated recently in a PDG report. The result for the second moment of the difference in $u$ and $d$ quark distributions $< x >_{u - d} = 0.187 \pm 0.021$ is seen to be well compatible with the latest LATTICE result $< x >_{u - d}^{LATTICE} = 0.208 \pm 0.024$
hep-phPhys.Atom.Nucl.(2018)·16 citations
08*
Study of the sign change of the Sivers function from STAR Collaboration W/Z production data
M. Anselmino (1,2)🇮🇹 · M. Boglione (1,2)🇮🇹 · U. D'Alesio (3,4)🇮🇹 · F. Murgia (4)🇮🇹 · A. Prokudin (5,6) ((1) University of Torino, Italy, (2) INFN, Torino, Italy, (3) University of Cagliari, Italy, (4) INFN, Cagliari, Italy, (5) Penn State University, USA, (6) JLab, Newport News, USA)🇺🇸
Recent data on the transverse single spin asymmetry $A_{N}$ measured by the STAR Collaboration for $p^{↑} p \to W^{\pm} / Z^{0} X$ reactions at RHIC allow the first investigation of the Sivers function in Drell-Yan processes and of its expected sign change with respect to SIDIS processes. A new extraction of the Sivers functions from the latest SIDIS data is performed and a critical assessment of the significance of the STAR data is attempted.
hep-phJHEP(2017)·97 citations
09*
Soft-gluon corrections for $t W$ production at N $^{3}$ LO
Nikolaos Kidonakis🇺🇸
I present approximate results that include third-order soft-gluon corrections for the associated production of a single top quark with a $W$ boson. The calculation uses expressions from soft-gluon resummation at next-to-next-to-leading-logarithm (NNLL) accuracy. From the NNLL resummed cross section I derive approximate next-to-next-to-next-to-leading order (aN $^{3}$ LO) cross sections for the process $b g \to t W^{-}$ at LHC and Tevatron energies. The aN $^{3}$ LO top-quark transverse-momentum and rapidity distributions in $t W$ production are also presented.
hep-phPRD(2017)·51 citations
10*
Equilibration and freeze-out of an expanding gas in a transport approach in a Friedmann-Robertson-Walker metric
J. Tindall🇬🇧 · J.M. Torres-Rincon🇩🇪 · J.B. Rose🇩🇪 · H. Petersen🇩🇪
Motivated by a recent finding of an exact solution of the relativistic Boltzmann equation in a Friedmann-Robertson-Walker spacetime, we implement this metric into the newly developed transport approach Simulating Many Accelerated Strongly-interacting Hadrons (SMASH). We study the numerical solution of the transport equation and compare it to this exact solution for massless particles. We also compare a different initial condition, for which the transport equation can be independently solved numerically. Very nice agreement is observed in both cases. Having passed these checks for the SMASH code, we study a gas of massive particles within the same spacetime, where the particle decoupling is forced by the Hubble expansion. In this simple scenario we present an analysis of the freeze-out times, as function of the masses and cross sections of the particles. The results might be of interest for their potential application to relativistic heavy-ion collisions, for the characterization of the freeze-out process in terms of hadron properties.
hep-phnucl-thPLB(2017)·25 citations
11*
Updated Collider and Direct Detection Constraints on Dark Matter Models for the Galactic Center Gamma-Ray Excess
Miguel Escudero🇪🇸 · Dan Hooper🇺🇸 · Samuel J. Witte🇺🇸
Utilizing an exhaustive set of simplified models, we revisit dark matter scenarios potentially capable of generating the observed Galactic Center gamma-ray excess, updating constraints from the LUX and PandaX-II experiments, as well as from the LHC and other colliders. We identify a variety of pseudoscalar mediated models that remain consistent with all constraints. In contrast, dark matter candidates which annihilate through a spin-1 mediator are ruled out by direct detection constraints unless the mass of the mediator is near an annihilation resonance, or the mediator has a purely vector coupling to the dark matter and a purely axial coupling to Standard Model fermions. All scenarios in which the dark matter annihilates through $t$ -channel processes are now ruled out by a combination of the constraints from LUX/PandaX-II and the LHC.
hep-phastro-ph.COastro-ph.HEJCAP(2017)·25 citations
12*
Indirect Searches of the Degenerate MSSM
Debtosh Chowdhury🇮🇹 · Ketan M. Patel🇮🇳 · Xerxes Tata🇺🇸 · Sudhir K. Vempati🇮🇳
A degenerate sfermionic particle spectrum can escape constraints from flavor physics, and at the same time evade the limits from the direct searches if the degeneracy extends to the gaugino-higgsino sector. Inspired by this, we consider a scenario where all the soft terms have an approximately common mass scale at $M_{SUSY}$ , with splittings $≲ O (10%)$ . As a result, the third generation sfermions have large to maximal (left-right) mixing, the same being the case with charginos and some sectors of the neutralino mass matrix. We study this scenario in the light of discovery of the Higgs boson with mass $\sim$ 125 GeV. We consider constraints from $B$ -physics, the anomalous magnetic moment of the muon and the dark matter relic density. We find that a supersymmetric spectrum as light as 600 GeV could be consistent with all current data and also account for the observed anomalous magnetic moment of the muon within $2 σ$ . The neutralino relic density is generally too small to saturate the measured cold dark matter relic density. Direct detection limits from XENON100 and LUX put severe constraints on this scenario which will be conclusively probed by XENONnT experiment.
hep-phhep-exPRD(2017)·12 citations
13*
Amplitude analysis and the nature of the Zc(3900)
JPAC Collaboration: A. Pilloni🇺🇸 · C. Fernandez-Ramirez🇲🇽 · A. Jackura🇺🇸 · V. Mathieu🇺🇸 · M. Mikhasenko🇩🇪 · J. Nys🇧🇪 · A.P. Szczepaniak🇺🇸
The microscopic nature of the XYZ states remains an unsettled topic. We show how a thorough amplitude analysis of the data can help constraining models of these states. Specifically, we consider the case of the Zc(3900) peak and discuss possible scenarios of a QCD state, virtual state, or a kinematical enhancement. We conclude that current data are not precise enough to distinguish between these hypotheses, however, the method we propose, when applied to the forthcoming high-statistics measurements should shed light on the nature of these exotic enhancements.
hep-phnucl-thPLB(2017)·103 citations
14*
Jet and heavy flavor production in heavy-ion collisions
Zhong-Bo Kang🇺🇸 · Felix Ringer🇺🇸 · Ivan Vitev🇺🇸
We review recent progress in the theoretical description of hard probes in heavy-ion collisions within the framework of Soft Collinear Effective Theory (SCET). Firstly, we consider the inclusive production of heavy flavor mesons and jets with a small radius parameter in proton-proton collisions. Secondly, we describe how in-medium effects can be incorporated consistently with the proton-proton baseline calculations. The in-medium interactions are described by Glauber gluon interactions. We present results for the nuclear modification factor $R_{AA}$ which is most commonly used to study the quenching of hadron or jet production yields in heavy-ion collisions and we compare to recent data from the LHC.
hep-phnucl-exnucl-thNucl.Part.Phys.Proc.(2017)·0 citations
15*
Decays of a NMSSM CP-odd Higgs in the low-mass region
Florian Domingo🇪🇸
A popular regime in the NMSSM parameter space involves a light CP-odd Higgs $A_{1}$ . This scenario has consequences for e.g. light singlino Dark Matter annihilating in the $A_{1}$ -funnel. In order to confront the pseudoscalar to experimental limits such as flavour observables, Upsilon decays or Beam-Dump experiments, it is necessary to control the interactions of this particle with hadronic matter and derive the corresponding decays. The partonic description cannot be relied upon for masses close to $m_{A_{1}} \sim 1$ GeV and we employ a chiral lagrangian, then extended to a spectator model for somewhat larger masses, to describe the interplay of the CP-odd Higgs with hadrons. Interestingly, a mixing can develop between $A_{1}$ and neutral pseudoscalar mesons, leading to substantial hadronic decays and a coupling of $A_{1}$ to the chiral anomaly. Additionally, quartic $A_{1}$ -meson couplings induce tri-meson decays of the Higgs pseudoscalar. We investigate these effects and propose an estimate of the Higgs widths for masses below $m_{A_{1}} \leq 3$ GeV. While we focus on the case of the NMSSM, our results are applicable to a large class of models.
hep-phJHEP(2017)·32 citations
16*
Oscillation characteristics of active and sterile neutrinos and neutrino anomalies at shot distances
V. V. Khruschov🇷🇺 · S. V. Fomichev🇷🇺 · O. A. Titov🇷🇺
A generalized phenomenological (3 + 2 + 1)-model with three active and three sterile neutrinos is considered for the calculation of the neutrino oscillation characteristics at normal mass hierarchy of active neutrinos and significant splitting between the mass of one sterile neutrino and the masses of other two sterile neutrinos. A new parametrization and a certain form of the general neutrino mixing matrix for active and sterile neutrinos are suggested taking into account the possible violation of CP invariance in the lepton sector. The test values of the neutrino masses and the mixing parameters are chosen. The transition probabilities for the different flavors of neutrino, which can be transformed into each other, are calculated, and the graphical dependences are obtained for the disappearance probability of muon neutrino/antineutrino and appearance probability of electron neutrino/antineutrino in the muon neutrino/antineutrino jet as a function of distance and other model parameters at their acceptable values and at neutrino energies not higher than 50 MeV, as well as a function of the ratio of the distance to the neutrino energy. It is shown that in the case of the mixing matrix of a definite type (of the a_2 type) between active and sterile neutrinos the explanation of the acceleration anomaly on small distances in the neutrino data (LSND anomaly) is possible, as well as the reactor and gallium anomalies. The theoretical results obtained can be used for the interpretation and prediction of results of the ground-based neutrino experiments on searching for the sterile neutrinos, and also for the analysis of certain astrophysical observation data.
hep-phPhys.Atom.Nucl.(2016)·20 citations
17*
The complete NLO corrections to dijet hadroproduction
Rikkert Frederix🇩🇪 · Stefano Frixione🇮🇹 · Valentin Hirschi🇺🇸 · Davide Pagani🇩🇪 · Hua-Sheng Shao🇨🇭 · Marco Zaro🇫🇷
We study the production of jets in hadronic collisions, by computing all contributions proportional to $α_{S}^{n} α^{m}$ , with $n + m = 2$ and $n + m = 3$ . These correspond to leading and next-to-leading order results, respectively, for single-inclusive and dijet observables in a perturbative expansion that includes both QCD and electroweak effects. We discuss issues relevant to the definition of hadronic jets in the context of electroweak corrections, and present sample phenomenological predictions for the 13-TeV LHC. We find that both the leading and next-to-leading order contributions largely respect the relative hierarchy established by the respective coupling-constant combinations.
hep-phJHEP(2017)·75 citations
18*
Heavy Higgs Boson Production at Colliders in the Singlet-Triplet Scotogenic Dark Matter Model
Marco Aurelio Díaz🇨🇱 · Nicolás Rojas🇪🇸 · Sebastián Urrutia-Quiroga🇨🇱 · José W. F. Valle🇪🇸
We consider the possibility that the dark matter particle is a scalar WIMP messenger associated to neutrino mass generation, made stable by the same symmetry responsible for the radiative origin of neutrino mass. We focus on some of the implications of this proposal as realized within the singlet-triplet scotogenic dark matter model.We identify consistent parameter sets consistent both with neutrino mass and the observed dark matter abundance. Finally we characterize the expected phenomenological profile of heavy Higgs boson physics at the LHC as well as at future linear Colliders.
hep-phJHEP(2017)·28 citations
19*
Present Status and Future Tests of the Higgsino-Singlino Sector in the NMSSM
Ulrich Ellwanger🇫🇷
The light higgsino-singlino scenario of the NMSSM allows to combine a naturally small $μ$ parameter with a good dark matter relic density. Given the new constraints on spin-dependent and spin-independent direct detection cross sections in 2016 we study first which regions in the plane of chargino- and LSP-masses below 300 GeV remain viable. Subsequently we investigate the impact of searches for charginos and neutralinos at the LHC, and find that the limits from run I do not rule out any additional region in this plane. Only the HL-LHC at 3000 fb $^{- 1}$ will test parts of this plane corresponding to higgsino-like charginos heavier than 150 GeV and relatively light singlinos, but notably the most natural regions with lighter charginos seem to remain unexplored.
hep-phJHEP(2017)·39 citations
20*
Quark and gluon TMD correlators in momentum and coordinate space
Tom van Daal🇳🇱
Transverse momentum dependent (TMD) distribution correlators can be parametrized in terms of TMD parton distribution functions (PDFs), or TMDs for short. We provide an overview of the leading-twist quark and gluon TMDs, both in momentum space and in coordinate space (also called $b_{T}$ -space, where $b_{T}$ is Fourier conjugate to the partonic momentum $k_{T}$ ). We consider unpolarized, vector polarized, as well as tensor polarized hadrons, which is relevant for spin- $0$ , spin- $1/2$ , and spin- $1$ hadrons.
hep-ph11 citations
21*
Probing Gluon TMDs at a Future EIC
Cristian Pisano🇮🇹 · Daniël Boer🇳🇱 · Piet J. Mulders🇳🇱 · Jian Zhou🇨🇳
Gluon TMDs can be accessed through the analysis of azimuthal asymmetries for heavy quark pair and dijet production in electron-proton collisions, similarly to the way quark TMDs are commonly extracted from semi-inclusive deep-inelastic scattering data. We calculate the upper bounds for these observables, showing in which kinematic regions they are large enough to be measured in future experiments at an Electron-Ion Collider. Moreover, we study their behavior in the small- $x$ region, adopting a McLerran-Venugopalan model for unpolarized and linearly polarized gluon distributions. By comparison with related observables at RHIC and LHC, we expect to gather information on the process dependence of the gluon TMDs and to test our prediction of a sign change of the gluon Sivers function and two other $T$ -odd gluon distributions.
hep-phPoS(2017)·1 citation
22*
Puzzles in eta photoproduction: the 1685~MeV narrow peak
Bojan Golli🇸🇮 · Simon Širca🇸🇮
We claim that a narrow peak in the cross section near 1685~MeV in the $γ n \to η n$ channel can be explained through a peculiar radial behaviour of the $p$ -wave quark states with $j = 1/2$ and $j = 3/2$ in the low lying S11 resonances and the opening of the $K Σ$ threshold rather than by an exotic resonance. We explain the mechanism of its formation in the framework of a coupled channel formalism which incorporates quasi-bound quark-model states corresponding to the two low lying resonances in the S11 partial wave. A relation to the Single Quark Transition Model is pointed out.
hep-phnucl-thBled Workshops Phys.(2016)·0 citations
23*
O(alpha_s alpha_t) (non)decoupling effects within the top-sector of the MSSM
L. Mihaila🇩🇪 · N. Zerf🇩🇪
In this paper we compute the $O (α_{s} α_{t})$ threshold corrections to the running strong coupling constant, the top-Yukawa coupling and the top-quark mass within the MSSM. These parameters present a non-decoupling behaviour with the supersymmetry scale $M_{SUSY}$ . Our numerical analysis shows that the mixed QCD-Yukawa corrections can amount to few GeV for the running top-quark mass and range at the percent level for the top-Yukawa coupling.
hep-phJHEP(2017)·11 citations
24*
A Boost to $h \to Z γ$ : from LHC to Future $e^{+} e^{-}$ Colliders
Jose Miguel No🇬🇧 · Michael Spannowsky🇬🇧
A precise measurement of the Higgs $h \to Z γ$ decay is very challenging at the LHC, due to the very low %SM $h \to Z γ (Z \to ℓℓ)$ branching fraction and the shortage of kinematic handles to suppress the large SM $Z γ$ background. We show how such a measurement would be significantly improved by considering Higgs production in association with a hard jet. We compare the prospective HL-LHC sensitivity in this channel with other Higgs production modes where $h$ is fairly boosted, e.g.~weak boson fusion, and also to the potential $h \to Z γ$ measurement achievable with a future $e^{+} e^{-}$ circular collider ({\sl fcc-ee}). Finally, we discuss new physics implications of a precision measurement of $h \to Z γ$ .
hep-phPRD(2017)·14 citations
25*
Estimating proton radius and proportion of other non-perturbative components in the proton by the Maximum Entropy Method
Chengdong Han🇨🇳 · Xurong Chen🇨🇳
In this paper, we apply the Maximum Entropy Method to estimate the proton radius and determine the valence quark distributions in the proton at extremely low resolution scale Q $_{0}^{2}$ . Using the simplest functional form of the valence quark distribution and standard deviations of quark distribution functions in the estimation of the proton radius, we obtain a quadratic polynomial for the relationship between the proton radius and the momentum fraction of other non-perturbative components in the proton. The proton radii are approximately equal to the muonic hydrogen experimental result $r_{p}$ = 0.841~fm and the CODATA analysis $r_{p}$ = 0.877 fm when the other non-perturbative components account for 17.5\% and 22.3\% respectively. We propose $" g h os t ma tt er "$ to explain the difference in other non-perturbative components (4.8\%) that the electron can detect.
hep-phCPC(2017)·2 citations
26*
Constraints on leptophilic dark matter from the AMS-02 experiment
Leila Ali Cavasonza🇩🇪 · Henning Gast🇩🇪 · Michael Krämer🇩🇪 · Mathieu Pellen🇩🇪 · Stefan Schael🇩🇪
The annihilation of dark matter particles in the galactic halo of the Milky Way may lead to cosmic ray signatures that can be probed by the AMS-02 experiment, which has measured the composition and fluxes of charged cosmic rays with unprecedented precision. Given the absence of characteristic spectral features in the electron and positron fluxes measured by AMS-02, we derive upper limits on the dark matter annihilation cross section for leptophilic dark matter models. Our limits are based on a new background model that describes all recent measurements of the energy spectra of cosmic ray positrons and electrons. For thermal dark matter relics, we can exclude dark matter masses below about 100 GeV. We include the radiation of electroweak gauge bosons in the dark matter annihilation process and compute the antiproton signal that can be expected within leptophilic dark matter models.
hep-phastro-ph.HEhep-exApJ(2017)·61 citations
27*
Self-interacting inelastic dark matter: A viable solution to the small scale structure problems
Mattias Blennow🇸🇪 · Stefan Clementz🇸🇪 · Juan Herrero-Garcia🇦🇺
Self-interacting dark matter has been proposed as a solution to the small-scale structure problems, such as the observed flat cores in dwarf and low surface brightness galaxies. If scattering takes place through light mediators, the scattering cross section relevant to solve these problems may fall into the non-perturbative regime leading to a non-trivial velocity dependence, which allows compatibility with limits stemming from cluster-size objects. However, these models are strongly constrained by different observations, in particular from the requirements that the decay of the light mediator is sufficiently rapid (before Big Bang Nucleosynthesis) and from direct detection. A natural solution to reconcile both requirements are inelastic endothermic interactions, such that scatterings in direct detection experiments are suppressed or even kinematically forbidden if the mass splitting between the two-states is sufficiently large. Using an exact solution when numerically solving the Schrödinger equation, we study such scenarios and find regions in the parameter space of dark matter and mediator masses, and the mass splitting of the states, where the small scale structure problems can be solved, the dark matter has the correct relic abundance and direct detection limits can be evaded.
hep-phJCAP(2017)·72 citations
28*
Structure of the Energy-Momentum Tensor and Applications
Jonathan Hudson (UConn)🇺🇸 · Irina A. Perevalova (Irkutsk State U.)🇷🇺 · Maxim V. Polyakov (St. Petersburg, INP & Ruhr U., Bochum)🇷🇺 · Peter Schweitzer (UConn)🇺🇸
The probably most fundamental information about a particle is contained in the matrix elements of its energy momentum tensor (EMT) which are accessible from hard-exclusive reactions via generalized parton distribution functions. The spin decomposition of the nucleon and Ji sum rule are one example. Less prominent but equally important information is encoded in the stress tensor, related to the spatial components of the EMT, which shows in detail how the strong forces inside the nucleon balance to form a bound state. This provides not only unique insights on nucleon structure. It also leads to fascinating new applications to hadron spectroscopy which allow us to formulate new interpretations of the charmonium-nucleon pentaquarks discovered by LHCb. Recent progress is reviewed in this short overview article.
hep-phhep-exnucl-exnucl-thPoS(2017)·8 citations
29*
Non-thermal leptogenesis with distinct CP violation and minimal dark matter
Hang Zhou🇨🇳 · Pei-Hong Gu🇨🇳
We demonstrate a unified scenario for neutrino mass, baryon asymmetry, dark matter and inflation. In addition to a fermion triplet for the so-called minimal dark matter, we extend the standard model by three heavy fields including a scalar singlet, a fermion triplet and a fermion singlet/Higgs triplet. The heavy scalar singlet, which is expected to drive an inflation, and the dark matter fermion triplet are odd under an unbroken $Z_{2}$ discrete symmetry, while the other fields are all even. The heavy fermion triplet offers a tree-level type-III seesaw and then mediates a three-body decay of the inflaton into the standard model lepton and Higgs doublets with the dark matter fermion triplet. The heavy fermion singlet/Higgs triplet not only results in a type-I/II seesaw at tree level but also contributes to the inflaton decay at one-loop level. In this scenario, the type-I/II seesaw contains all of the physical CP phases in the lepton sector and hence the CP violation for the non-thermal leptogenesis by the inflaton decay exactly comes from the imaginary part of the neutrino mass matrix.
hep-phJCAP(2017)·2 citations
30*
Ultra-Light Dark Matter Resonates with Binary Pulsars
Diego Blas🇨🇭 · Diana Lopez Nacir🇨🇭 · Sergey Sibiryakov🇨🇭
We consider the scenario where dark matter (DM) is represented by an ultra-light classical scalar field performing coherent periodic oscillations. We point out that such DM perturbs the dynamics of binary systems either through its gravitational field or via direct coupling to ordinary matter. This perturbation gets resonantly amplified if the frequency of DM oscillations is close to a (half-)integer multiple of the orbital frequency of the system and leads to a secular variation of the orbital period. We suggest to use binary pulsars as probes of this scenario and estimate their sensitivity. While the current accuracy of observations is not yet sufficient to probe the purely gravitational effect of DM, it already yields constraints on direct coupling that are competitive with other bounds. The sensitivity will increase with the upcoming radio observatories such as Square Kilometer Array.
hep-phastro-ph.COastro-ph.HEPRL(2017)·130 citations
31*
Exploring viable vacua of the $Z_{3}$ -symmetric NMSSM
Jyotiranjan Beuria🇮🇳 · Utpal Chattopadhyay🇮🇳 · AseshKrishna Datta🇮🇳 · Abhishek Dey🇮🇳
We explore the vacua of the $Z_{3}$ -symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM) and their stability by going beyond the simplistic paradigm that works with a tree-level neutral scalar potential and adheres to some specific flat directions in the field space. Key effects are demonstrated by first studying the profiles of this potential under various circumstances of physical interest via a semi-analytical approach. The results thereof are compared to the ones obtained from a dedicated package like \veva ~which further incorporates the thermal effects to the potential. Regions of the phenomenological NMSSM (pNMSSM) parameter space that render the desired symmetry breaking (DSB) vacuum absolutely stable, long- or short-lived (in relation to the age of the Universe) under quantum/thermal tunneling are delineated. Regions that result in color and charge breaking (CCB) minima are also presented. It is demonstrated that light singlet scalars along with a light LSP (lightest supersymmetric particle) having an appreciable singlino admixture are compatible with a viable DSB vacuum and are much relevant for the collider experiments.
hep-phhep-exJHEP(2017)·19 citations
32*
Biasing and the search for primordial non-Gaussianity beyond the local type
Jérôme Gleyzes🇺🇸 · Roland de Putter🇺🇸 · Daniel Green🇺🇸 · Olivier Doré🇺🇸
Primordial non-Gaussianity encodes valuable information about the physics of inflation, including the spectrum of particles and interactions. Significant improvements in our understanding of non-Gaussanity beyond Planck require information from large-scale structure. The most promising approach to utilize this information comes from the scale-dependent bias of halos. For local non-Gaussanity, the improvements available are well studied but the potential for non-Gaussianity beyond the local type, including equilateral and quasi-single field inflation, is much less well understood. In this paper, we forecast the capabilities of large-scale structure surveys to detect general non-Gaussianity through galaxy/halo power spectra. We study how non-Gaussanity can be distinguished from a general biasing model and where the information is encoded. For quasi-single field inflation, significant improvements over Planck are possible in some regions of parameter space. We also show that the multi-tracer technique can significantly improve the sensitivity for all non-Gaussianity types, providing up to an order of magnitude improvement for equilateral non-Gaussianity over the single-tracer measurement.
↳ astro-ph.COhep-phhep-thJCAP(2017)·54 citations
33*
Dark Matter and Inflation in $R + ζ R^{2}$ Supergravity
Andrea Addazi🇮🇹 · Maxim Yu. Khlopov🇷🇺
As is well known, the gravitational degrees of freedom contained in $R + ζ R^{2}$ (super)gravity lead to Starobinsky's potential, in a one-field setting for inflationary Cosmology that appears favored by Planck data. In this letter we discuss another interesting aspect of this model, related to gravitino production, with emphasis on the corresponding mass spectrum. Assuming that supersymmetry is broken at a very high scale, Super Heavy Gravitino Dark Matter (SHGDM) and Starobinsky's inflation can be coherently unified in a $R + ζ R^{2}$ supergravity. Gravitinos are assumed to be the Lightest Supersymmetric Particles (LSP) and are non-thermally produced during inflation, in turn originated by a scalar with a Starobinsky's potential. Gravitino mass runs with the inflaton field, so that a continuos spectrum of superheavy gravitinos emerges. The theory is implemented with a $U (1)_{R}$ gauge symmetry. However, in a string UV completion, $U (1)_{R}$ -symmetry can be broken by non-perturbative string instantons, while for consistency of our scenario $U (1)_{R}$ gauge symmetry breaking must be broken in order to generate a soft mass terms for the gravitino and gauginos. R-parity violating operators can be generated at non-perturbative level. Gravitinos can decay into very energetic neutrinos and photons in cosmological time scale, with intriguing implications for high energy cosmic rays experiments.
↳ gr-qchep-phhep-thPLB(2017)·26 citations
34*
On the perturbative renormalisation of four-quark operators for new physics
Mauro Papinutto🇮🇹 · Carlos Pena🇪🇸 · David Preti🇪🇸
We discuss the renormalisation properties of the full set of $Δ F = 2$ operators involved in BSM processes, including the definition of RGI versions of operators that exhibit mixing under RG transformations. As a first step for a fully non-perturbative determination of the scale-dependent renormalization factors and their runnings, we introduce a family of appropriate Schrödinger Functional schemes, and study them in perturbation theory. This allows, in particular, to determine the NLO anomalous dimensions of all $Δ F = 1, 2$ operators in these schemes. Finally, we discuss the systematic uncertainties related to the use of NLO perturbation theory for the RG running of four-quark operators to scales in the GeV range, in both our SF schemes and standard $M S$ and RI-MOM schemes. Large truncation effects are found for some of the operators considered.
↳ hep-lathep-phEPJC(2017)·26 citations
35*
Effects of volume corrections and resonance decays on cumulants of net-charge distributions in a Monte Carlo hadron resonance gas model
Hao-jie Xu🇨🇳
The effects of volume corrections and resonance decays (the resulting correlations between positive charges and negative charges) on cumulants of net-proton distributions and net-charge distributions are investigated by using a Monte Carlo hadron resonance gas ({\tt MCHRG}) model. The required volume distributions are generated by a Monte Carlo Glauber ({\tt MC-Glb}) model. Except the variances of net-charge distributions, the {\tt MCHRG} model with more realistic simulations of volume corrections, resonance decays and acceptance cuts can reasonably explain the data of cumulants of net-proton distributions and net-charge distributions reported by the STAR collaboration. The {\tt MCHRG} calculations indicate that both the volume corrections and resonance decays make the cumulant products of net-charge distributions deviate from the Skellam expectations: the deviations of $S σ$ and $κ σ^{2}$ are dominated by the former effect while the deviations of $ω$ are dominated by the latter one.
↳ nucl-thhep-phnucl-exPLB(2017)·25 citations
36*
Determining reactor fuel type from continuous antineutrino monitoring
Patrick Jaffke🇺🇸 · Patrick Huber🇺🇸
We investigate the ability of an antineutrino detector to determine the fuel type of a reactor. A hypothetical 5t antineutrino detector is placed 25m from the core and measures the spectral shape and rate of antineutrinos emitted by fission fragments in the core for a number of 90 day periods. Our results indicate that four major fuel types can be differentiated from the variation of fission fractions over the irradiation time with a true positive probability of detection at 95%. In addition, we demonstrate that antineutrinos can identify the burn-up at which weapons-grade mixed-oxide (MOX) fuel would be reduced to reactor-grade MOX on average, providing assurance that plutonium disposition goals are met. In addition, we investigate removal scenarios where plutonium is purposefully diverted from a mixture of MOX and low-enriched uranium (LEU) fuel. Finally, we discuss how our analysis is impacted by a spectral distortion around 6MeV observed in the antineutrino spectrum measured from commercial power reactors.
↳ physics.ins-dethep-exhep-phnucl-exPhys.Rev.Applied(2017)·17 citations
37*
Inconsistency of Minkowski higher-derivative theories
Ugo G. Aglietti🇮🇹 · Damiano Anselmi🇮🇹
We show that Minkowski higher-derivative quantum field theories are generically inconsistent, because they generate nonlocal, non-Hermitian ultraviolet divergences, which cannot be removed by means of standard renormalization procedures. By "Minkowski theories" we mean theories that are defined directly in Minkowski spacetime. The problems occur when the propagators have complex poles, so that the correlation functions cannot be obtained as the analytic continuations of their Euclidean versions. The usual power counting rules fail and are replaced by much weaker ones. Self-energies generate complex divergences proportional to inverse powers of D'Alembertians. Three-point functions give more involved nonlocal divergences, which couple to infrared effects. We illustrate the violations of the locality and Hermiticity of counterterms in scalar models and higher-derivative gravity.
↳ hep-thhep-phEPJC(2017)·25 citations
38*
Magnetic fields in turbulent quark matter and magnetar bursts
Maxim Dvornikov (IZMIRAN, Tomsk State University)🇷🇺
We analyze the magnetic field evolution in dense quark matter with unbroken chiral symmetry, which can be found inside quark and hybrid stars. The magnetic field evolves owing to the chiral magnetic effect in the presence of the electroweak interaction between quarks. In our study, we also take into account the magnetohydrodynamic turbulence effects in dense quark matter. We derive the kinetic equations for the spectra of the magnetic helicity density and the magnetic energy density as well as for the chiral imbalances. On the basis of the numerical solution of these equations, we find that turbulence effects are important for the behavior of small scale magnetic fields. It is revealed that, under certain initial conditions, these magnetic fields behave similarly to the electromagnetic flashes of some magnetars. We suggest that fluctuations of magnetic fields, described in frames of our model, which are created in the central regions of a magnetized compact star, can initiate magnetar bursts.
↳ astro-ph.HEhep-phnucl-thInt.J.Mod.Phys.D(2018)·11 citations
39*
Recent progress on dense nuclear matter in skyrmion approaches
Yong-Liang Ma🇨🇳 · Mannque Rho🇫🇷
The Skyrme model provides a novel unified approach to nuclear physics. In this approach, single baryon, baryonic matter and medium-modified hadron properties are treated on the same footing. Intrinsic density dependence (IDD) reflecting the change of vacuum by compressed baryonic matter figures naturally in the approach. In this article, we review the recent progress on accessing dense nuclear matter by putting baryons treated as solitons, namely, skyrmions, on crystal lattice with accents on the implications in compact stars.
↳ nucl-thhep-phSCPMA(2017)·32 citations
40*
Counting the number of master integrals for sunrise-type Feynman diagrams via Mellin-Barnes representation
Mikhail Yu. Kalmykov🇩🇪 · Bernd A.Kniehl🇩🇪
A number of irreducible master integrals for L-loop sunrise-type and bubble Feynman diagrams with generic values of masses and external momenta are explicitly evaluated via Mellin-Barnes representation.
↳ hep-thhep-phmath-phmath.CA+1JHEP(2017)·42 citations
41*
Quark number susceptibilities and equation of state at finite chemical potential in staggered QCD with Nt=8
Saumen Datta🇮🇳 · Rajiv V. Gavai🇮🇳 · Sourendu Gupta🇮🇳
We report the measurement of quark number susceptibilities (QNS) and their temperature dependence from simulations of QCD with two flavours of light dynamical staggered quarks at finite temperature on 8 * 32^3 lattices. From the radius of convergence of the Taylor expansion we estimate the critical end point. We use a Pade approximant to resum the series expansion and compute the equation of state at finite chemical potential, namely the baryon number density and its contribution to the pressure. We also report the isothermal compressibility of QCD matter at finite baryon density. Finally we explore the freezeout conditions for a measure of fluctuations. We examine some sources of systematic and statistical errors in all of these measurements.
↳ hep-lathep-phPRD(2017)·68 citations
42*
On the Implications of Energy and Momentum Conservation for Particle Emission in A+A Collisions at SPS Energies
Antoni Szczurek🇵🇱 · Mirosław Kiełbowicz🇵🇱 · Andrzej Rybicki🇵🇱
We construct a simple model of heavy ion collisions, local in the impact parameter plane, and appropriate for the SPS energy range. This model can be regarded as a new realization of the "fire-streak" approach, originally applied to studies of lower energy nucleus-nucleus reactions. Starting from local energy and momentum conservation, we nicely describe the broadening of the pion rapidity distribution when going from central to peripheral Pb+Pb collisions at $s_{N N}$ =17.3 GeV. The results of our calculations are compared with SPS experimental data. We discuss the resulting implications on the role of energy and momentum conservation for the dynamics of particle production in heavy ion collisions. A specific space-time picture emerges, where the longitudinal evolution of the system strongly depends on the position in the impact parameter ( $b_{x}$ , $b_{y}$ ) plane. This picture is consistent with our earlier findings on the longitudinal evolution of the system as deduced from electromagnetic effects on charged pion directed flow, and can provide an explanation for specific low- $p_{T}$ phenomena seen in the fragmentation region of Pb+Pb collisions.
↳ nucl-thhep-phPRC(2017)·16 citations
43*
Exploring phases of dense QCD with compact stars
Armen Sedrakian🇩🇪
I review a number of recent developments in the physics of compact stars containing deconfined quark matter, including (a)~their cooling with possible phase transition from a fully gapped to a gapless phase of QCD at low temperatures and large isospin, (b)~the transport coefficients of the 2SC phase and the role played by the Aharonov-Bohm interactions between flux-tubes and unpaired fermions; (c)~rapidly rotating compact stars and spin-down and spin-up induced phase transition between hadronic and QCD matter as well as between different phases of QCD.
↳ astro-ph.HEhep-phnucl-thEPJ Web Conf.(2017)·5 citations
44*
Rapidity-dependent jet energy loss in small systems with finite-size effects and running coupling
Chanwook Park🇨🇦 · Chun Shen🇺🇸 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦
Longitudinal dynamics of particle production and rapidity-dependent jet energy loss are investigated in small and asymmetric colliding systems. We utilize an improved version of \textsc{martini} in which two improvements are implemented to calculate the effect of the strongly coupled QGP droplet on jet energy loss. We show that those realistic prescriptions improve the results of nuclear modification factor calculations. We also observe visible energy loss of jets in a thermal background of high-multiplicity p-Pb collisions, and a clear correlation between the energy loss and elliptic flow coefficients for energetic particles. We conclude that systematic measurements of jet quenching in central collisions of small systems can support the formation of the QGP droplet.
↳ nucl-thhep-phnucl-exNucl.Part.Phys.Proc.(2017)·23 citations
45*
On the search for the electric dipole moment of strange and charm baryons at LHC
F.J. Botella🇪🇸 · L.M. Garcia Martin🇪🇸 · D. Marangotto🇮🇹 · F. Martinez Vidal🇪🇸 · A. Merli🇮🇹 · N. Neri🇮🇹 · A. Oyanguren🇪🇸 · J. Ruiz Vidal🇪🇸
Permanent electric dipole moments (EDMs) of fundamental particles provide powerful probes for physics beyond the Standard Model. We propose to search for the EDM of strange and charm baryons at LHC, extending the ongoing experimental program on the neutron, muon, atoms, molecules and light nuclei. The EDM of strange Lambda baryons, selected from weak decays of charm baryons produced in pp collisions at LHC, can be determined by studying the spin precession in the magnetic field of the detector tracking system. A test of CPT symmetry can be performed by measuring the magnetic dipole moment of Lambda and anti-Lambda baryons. For short-lived Lambdac+ and Xic+ baryons, to be produced in a fixed-target experiment using the 7 TeV LHC beam and channeled in a bent crystal, the spin precession is induced by the intense electromagnetic field between crystal atomic planes. The experimental layout based on the LHCb detector and the expected sensitivities in the coming years are discussed.
↳ hep-exhep-phEPJC(2017)·93 citations
46*
Extracting $q^$ from single inclusive data at RHIC and at the LHC for different centralities: a new puzzle?
Carlota Andres🇪🇸 · Nestor Amesto🇪🇸 · Matthew Luzum🇧🇷 · Carlos A. Salgado🇪🇸 · Pia Zurita🇺🇸
We present here an extraction of the jet transport coefficient, $q^$ , using RHIC and LHC single-inclusive high- $p_{T}$ data for different centralities. We fit a $K$ -factor that determines the deviation of this coefficient from an ideal estimate, $K \equiv q^/ (2 ϵ^{3/4})$ , where $ϵ$ is given by hydrodynamic simulations. As obtained already in previous studies, this $K$ -factor is found to be larger at RHIC than at the LHC. However it is, unexpectedly, basically no-dependent on the centrality of the collision. Taken at face value this result, the $K$ -factor would not depend on local properties of the QGP as temperature, but on global collision variables such as the center of mass energy.
↳ nucl-thhep-phnucl-exNucl.Part.Phys.Proc.(2017)·5 citations
47*
One-loop calculations in Supersymmetric Lattice QCD
M. Costa🇨🇾 · H. Panagopoulos🇨🇾
We study the self energies of all particles which appear in a lattice regularization of supersymmetric QCD ( $N = 1$ ). We compute, perturbatively to one-loop, the relevant two-point Green's functions using both the dimensional and the lattice regularizations. Our lattice formulation employs the Wilson fermion acrion for the gluino and quark fields. The gauge group that we consider is $S U (N_{c})$ while the number of colors, $N_{c}$ and the number of flavors, $N_{f}$ , are kept as generic parameters. We have also searched for relations among the propagators which are computed from our one-loop results. We have obtained analytic expressions for the renormalization functions of the quark field ( $Z_{ψ}$ ), gluon field ( $Z_{u}$ ), gluino field ( $Z_{λ}$ ) and squark field ( $Z_{A_{\pm}}$ ). We present here results from dimensional regularization, relegating to a forthcoming publication our results along with a more complete list of references. Part of the lattice study regards also the renormalization of quark bilinear operators which, unlike the non-supersymmetric case, exhibit a rich pattern of operator mixing at the quantum level.
↳ hep-lathep-phEPJ Web Conf.(2017)·0 citations
48*
Search for Dark Matter Annihilation in the Earth using the ANTARES Neutrino Telescope
ANTARES Collaboration: A. Albert🇫🇷 · M. André🇪🇸 · M. Anghinolfi🇮🇹 · G. Anton🇩🇪 · M. Ardid🇪🇸 · J.-J. Aubert🇫🇷 · T. Avgitas🇫🇷 · B. Baret🇫🇷 · J. Barrios-Martí🇪🇸 · S. Basa🇫🇷 · V. Bertin🇫🇷 · S. Biagi🇮🇹 and 116 other authors
A search for a neutrino signal from WIMP pair annihilations in the centre of the Earth has been performed with the data collected with the ANTARES neutrino telescope from 2007 to 2012. The event selection criteria have been developed and tuned to maximise the sensitivity of the experiment to such a neutrino signal. No significant excess of neutrinos over the expected background has been observed. Upper limits at $90%$ C.L. on the WIMP annihilation rate in the Earth and the spin independent scattering cross-section of WIMPs to nucleons $σ_{p}^{S I}$ were calculated for WIMP pair annihilations into either $τ^{+} τ^{-}$ , $W^{+} W^{-}$ , $b b$ or the non-SUSY $ν_{μ} ν ˉ_{μ}$ as a function of the WIMP mass (between $25 GeV/ c^{2}$ and $1000 GeV/ c^{2}$ ) and as a function of the thermally averaged annihilation cross section times velocity $⟨ σ_{A} v ⟩_{E a r t h}$ of the WIMPs in the centre of the Earth. For masses of the WIMP close to the mass of iron nuclei ( $50 GeV/ c^{2}$ ), the obtained limits on $σ_{p}^{S I}$ are more stringent than those obtained by other indirect searches.
↳ hep-exhep-phPhys.Dark Univ.(2017)·55 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.