Mon·May 14, 2018Monday·May 14, 2018

1. 01*

   Meson-Hybrid Mixing in $J^{PC}=1^{++}$ Heavy Quarkonium from QCD Sum-Rules

   A. Palameta🇨🇦 · D. Harnett🇨🇦 · T. G. Steele🇨🇦

   We explore conventional meson-hybrid mixing in $J^{PC}=1^{++}$ heavy quarkonium using QCD Laplace sum-rules. We calculate the cross-correlator between a heavy conventional meson current and heavy hybrid current within the operator product expansion, including terms proportional to the four- and six-dimensional gluon condensates and the six-dimensional quark condensate. Using experimentally determined hadron masses, we construct models of the $1^{++}$ charmonium and bottomonium mass spectra. These models are used to investigate which resonances couple to both currents and thus exhibit conventional meson-hybrid mixing. In the charmonium sector, we find almost no conventional meson-hybrid mixing in the ${\chi }_{c1}(1P)$, minimal mixing in the $X(3872)$, and significant mixing in both the $X(4140)$ and $X(4274)$. In the bottomonium sector, we find minimal conventional meson-hybrid mixing in the ${\chi }_{b1}(1P)$ and significant mixing in both the ${\chi }_{b1}(2P)$ and ${\chi }_{b1}(3P)$.

   hep-phPRD(2018)·23 citations
2. 02*

   Heavy Gravitino from Dynamical Generation of Right-Handed Neutrino Mass Scale, and Gravitational Waves

   Ryo Nagai🇯🇵 · Fuminobu Takahashi🇯🇵 · Norimi Yokozaki🇯🇵

   The absence of supersymmetric particles at the weak scale is a puzzle if supersymmetry solves the gauge hierarchy problem. We show that, if the right-handed neutrino masses arise from hidden gaugino condensation via GUT-suppressed operators, successful thermal leptogenesis leads to the lower bound on the gravitino mass, which may explain the little hierarchy problem. If domain walls associated with the gaugino condensation are formed after inflation, they annihilate when $H\sim m_{3/2}$. We address the possibility that observable gravitational wave signals might emerge from the domain wall annihilation.

   hep-phhep-exPLB(2018)·0 citations
3. 03*

   Impact of cosmological and astrophysical constraints on dark matter simplified models

   Chiara Arina🇧🇪

   Studies of dark matter models lie at the interface of astrophysics, cosmology, nuclear physics and collider physics. Constraining such models entails the capability to compare their predictions to a wide range of observations. In this review, we present the impact of global constraints to a specific class of models, called dark matter simplified models. These models have been adopted in the context of collider studies to classify the possible signatures due to dark matter production, with a reduced number of free parameters. We classify the models that have been analysed so far and for each of them we review in detail the complementarity of relic density, direct and indirect searches with respect to the LHC searches. We also discuss the capabilities of each type of search to identify regions where individual approaches to dark matter detection are the most relevant to constrain the model parameter space. Finally we provide a critical overview on the validity of the dark matter simplified models and discuss the caveats for the interpretation of the experimental results extracted for these models.

   hep-phFront.Astron.Space Sci.(2018)·32 citations
4. 04*

   How to locate the QCD phase boundary by scanning observable in the phase plane

   Yan-Hua Zhang🇨🇳 · Xue Pan🇨🇳 · Li-Zhu Chen🇨🇳 · Ming-Mei Xu🇨🇳 · Zhi-Ming Li🇨🇳 · Ye-Yin Zhao🇨🇳 · Yuan-Fang Wu🇨🇳

   For small volume of the quark-gluon plasma formed in heavy ion collisions, the observable near criticality must obey finite-size scaling. According to the finite-size scaling, there exists a fixed point at the critical temperature, where scaled susceptibility at different system sizes intersect. It also exists at the transitional temperature of a first order phase transition and can be generalized to the region of the crossover. In order to quantify the feature of the fixed point, we introduce {\it the width of a set of points}. When all points in the set are in their mean position within error, the width reaches its minimum, and all points merge into the fixed point. Using the observable produced by the Potts model, we demonstrate that the contour plot of the width defined in this study clearly indicates the temperatures and exponent ratios of fixed point, which could correspond to either the critical point, the points on the transition line, or the crossover region. This method is therefore instructive to the determination of QCD phase boundary by beam energy scan in relativistic heavy ion collisions.

   hep-ph0 citations
5. 05*

   Supersymmetric gauged U(1)${}_{L_{\mu }-L_{\tau }}$ model for neutrinos and the muon $(g-2)$ anomaly

   Heerak Banerjee🇮🇳 · Pritibhajan Byakti🇮🇳 · Sourov Roy🇮🇳

   The gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ model can provide for additional contributions to the muon anomalous magnetic moment by means of a loop involving the $Z^{\prime }$ gauge boson. However, the parameter space of such models is severely constrained if one combines the latest muon $(g-2)$ data with various neutrino experiments, such as neutrino trident production, $\nu -e$ and $\nu -q$ elastic scattering, etc. In a supersymmetric $U(1{)}_{L_{\mu }-L_{\tau }}$ model, a larger region of parameter space opens up, thus enabling one to explore otherwise forbidden regions of parameter space in nonsupersymmetric models involving the new gauge coupling ($g_X$) and the mass of the $Z^{\prime }$ gauge boson ($M_{Z^{\prime }}$) . We show that the minimal model with the minimal supersymmetric Standard Model (MSSM) field content is strongly disfavored from $Z$-boson decay and neutrino data. We also show that the nonminimal model with two extra singlet superfields can lead to correct neutrino masses and mixing involving both tree-level and one-loop contributions. We find that, in this model, both muon $(g-2)$ and neutrino data may be simultaneously explained in a parameter region consistent with experimental observations. In addition, we observe that the muon $(g-2)$ anomaly can be accommodated even with higher values of electroweak sparticle masses compared to the MSSM. Charged lepton-flavor-violating processes (like $\mu \to e\gamma$, $\tau \to \mu \gamma$, etc.) may have potentially large branching ratios in this scenario. Depending on the magnitude of the supersymmetry contribution to these processes, they may constrain hitherto unconstrained regions of the $M_{Z^{\prime }}-g_X$ parameter space. However, we find that these branching fractions never exceed their upper bounds in a region where both muon $(g-2)$ and neutrino oscillation data can be simultaneously accommodated.

   hep-phPRD(2018)·33 citations
6. 06*

   Can We Reach the Scale of New Physics Behind the $B$ Anomalies?

   Tevong You🇬🇧

   Indirect signs of new physics beyond the Standard Model may be appearing in $B\to K^{(\ast )}{\mu }^{+}{\mu }^{-}$ decays. If confirmed, the title question will be of paramount importance in determining the strategy for future colliders. We answer it by estimating the sensitivity to minimal, anomaly-compatible $Z^{\prime }$ and leptoquark models at the high luminosity LHC, 27 TeV HE-LHC, and 100 TeV FCC-hh; this conservative analysis outlines an upper bound on the available parameter space and the conditions for a reasonable guarantee of direct discovery.

   hep-phhep-ex1 citation
7. 07*

   Singlet-Doublet Dark Matter Freeze-in: LHC displaced signatures versus cosmology

   Lorenzo Calibbi🇨🇳 · Laura Lopez-Honorez🇧🇪 · Steven Lowette🇧🇪 · Alberto Mariotti🇧🇪

   We study the Singlet-Doublet dark matter model in the regime of feeble couplings, where the dark matter abundance is obtained via the freeze-in mechanism. As a consequence of the small couplings, the heavier particles in the model are long-lived with decay length at typical scales of collider experiments. We analyse the collider signatures of the model, characterised by displaced $h$ and $Z$ bosons plus missing momentum, employing current LHC searches for displaced vertices and missing energy to significantly constrain the parameter space of the model. We also take into account the cosmological bounds relevant for our light dark matter candidate arising from Lyman-$\alpha$ forest constraints. Our analysis emphasises the interplay between displaced signatures at the LHC and cosmology for dark matter candidates whose relic abundance is obtained through the freeze-in mechanism.

   hep-phJHEP(2018)·84 citations
8. 08*

   Natural explanation for 21cm absorption signals via axion-induced cooling

   Nick Houston🇨🇳 · Chuang Li🇨🇳 · Tianjun Li🇨🇳 · Qiaoli Yang🇨🇳 · Xin Zhang🇨🇳

   The EDGES Collaboration has reported an anomalously strong 21cm absorption feature corresponding to the era of first star formation, which may indirectly betray the influence of dark matter during this epoch. We demonstrate that, by virtue of the ability to mediate cooling processes whilst in the condensed phase, a small amount of axion dark matter can explain these observations within the context of standard models of axions and axion-like-particles. The EDGES best-fit result favours an axion-like-particles mass in the (10, 450) meV range, which can be compressed for the QCD axion to (100, 450) meV in the absence of fine tuning. Future experiments and large scale surveys, particularly the International Axion Observatory (IAXO) and EUCLID, should have the capability to directly test this scenario.

   hep-phastro-ph.COPRL(2018)·39 citations
9. 09*

   Fourier coefficients of the net-baryon number density and chiral criticality

   Gabor Andras Almasi🇭🇺 · Bengt Friman🇩🇪 · Kenji Morita🇯🇵 · Pok Man Lo🇵🇱 · Krzysztof Redlich🇵🇱

   We investigate the Fourier coefficients $b_k(T)$ of the net--baryon number density in strongly interacting matter at nonzero temperature and density. The asymptotic behavior of the coefficients at large $k$ is determined by the singularities of the partition function in the complex chemical potential plane. Within a QCD-like effective chiral model, we show that the chiral and deconfinement properties at nonzero baryon chemical potential are reflected in characteristic $k$-- and $T$-- dependences of the Fourier coefficients. We also discuss the influence of the Roberge-Weiss transition on these coefficients. Our results indicate that the Fourier expansion approach can provide interesting insights into the criticality of QCD matter.

   hep-phPRD(2019)·21 citations
10. 10*

    Baryon clustering at the critical line and near the hypothetical critical point in heavy-ion collisions

    Edward Shuryak🇺🇸 · Juan M. Torres-Rincon🇺🇸

    We study clustering of baryons at the freeze-out point of relativistic heavy-ion collisions. Using a Walecka-Serot model for the nucleon-nucleon (NN) interaction we analyze how the modified/critical $\sigma$ mode---responsible for the NN attraction---allows for clustering of nucleons when the system is close to a possible critical point of QCD. We investigate clusters of few nucleons, and also the internal cluster configuration when the system is long lived. For realistic heavy-ion collisions we study to how extend such clusters can be formed in a finite time, and perform the statistical analysis of cumulants and higher-order moments (skewness and kurtosis) for collisions at the Beam Energy Scan of RHIC.

    hep-phnucl-exnucl-thPRC(2019)·50 citations
11. 11*

    Higgs-boson plus Dijets: Higher-Order Matching for High-Energy Predictions

    Jeppe R. Andersen🇬🇧 · Tuomas Hapola🇬🇧 · Marian Heil🇬🇧 · Andreas Maier🇬🇧 · Jennifer M. Smillie🇬🇧

    Several important processes and analyses at the LHC are sensitive to higher-order perturbative corrections beyond what can currently be calculated at fixed order. The formalism of High Energy Jets (HEJ) calculates the corrections systematically enhanced for a large ratio of the centre-of-mass energy to the transverse momentum of the observed jets. These effects are relevant in the analysis of e.g. Higgs-boson production in association with dijets within the cuts devised to enhance the contribution from Vector Boson Fusion (VBF). HEJ obtains an all-order approximation, based on logarithmic corrections which are matched to fixed-order results in the cases where these can be readily evaluated. In this paper we present an improved framework for the matching utilised in HEJ, which for merging of tree-level results is mathematically equivalent to the one used so far. However, by starting from events generated at fixed order and supplementing these with the all-order summation, it is computationally simpler to obtain matching to calculations of high multiplicity. We demonstrate that the impact of the higher-multiplicity matching on predictions is small for the gluon-fusion (GF) contribution of Higgs-boson production in association with dijets in the VBF-region, so perturbative stability against high-multiplicity matching has been achieved within HEJ. We match the improved HEJ prediction to the inclusive next-to-leading order (NLO) cross section and compare to pure NLO in the h->photon photon channel with standard VBF cuts.

    hep-phJHEP(2018)·26 citations
12. 12*

    Lorentz and CPT Tests with Clock-Comparison Experiments

    Alan Kostelecky🇺🇸 · Arnaldo J. Vargas🇺🇸

    Clock-comparison experiments are among the sharpest existing tests of Lorentz symmetry in matter. We characterize signals in these experiments arising from modifications to electron or nucleon propagators and involving Lorentz- and CPT-violating operators of arbitrary mass dimension. The spectral frequencies of the atoms or ions used as clocks exhibit perturbative shifts that can depend on the constituent-particle properties and can display sidereal and annual variations in time. Adopting an independent-particle model for the electronic structure and the Schmidt model for the nucleus, we determine observables for a variety of clock-comparison experiments involving fountain clocks, comagnetometers, ion traps, lattice clocks, entangled states, and antimatter. The treatment demonstrates the complementarity of sensitivities to Lorentz and CPT violation among these different experimental techniques. It also permits the interpretation of some prior results in terms of bounds on nonminimal coefficients for Lorentz violation, including first constraints on nonminimal coefficients in the neutron sector. Estimates of attainable sensitivities in future analyses are provided. Two technical appendices collect relationships between spherical and cartesian coefficients for Lorentz violation and provide explicit transformations converting cartesian coefficients in a laboratory frame to the canonical Sun-centered frame.

    hep-phphysics.atom-phquant-phPRD(2018)·63 citations
13. 13*

    Astrophysical Signatures of Asymmetric Dark Matter Bound States

    Moira I. Gresham🇺🇸 · Hou Keong Lou🇺🇸 · Kathryn M. Zurek🇺🇸

    Nuggets---very large stable bound objects arising in the presence of a sufficiently attractive and long-range force and in the absence of a dark Coulomb force---are a smoking gun signature for Asymmetric Dark Matter (ADM). The cosmology of ADM nuggets is both generic and unique: nuggets feature highly exothermic fusion processes, which can impact the shape of the core in galaxies, as well as give rise to rare dark star formation. We find, considering the properties of nuggets in a generic extended nuclear model with both attractive and repulsive forces, that self-interaction constraints place an upper bound on nugget masses at the freeze-out of synthesis in the ballpark of $M_{\mathrm{fo}}\lesssim 10^{16}$ GeV. We also show that indirect detection strongly constrains models where the scalar mediator binding the nuggets mixes with the Higgs.

    hep-phastro-ph.HEPRD(2018)·81 citations
14. 14*

    Reducing the Quadratic Divergence in the Higgs Mass Squared Without Top Partners

    Sonia El Hedri🇳🇱 · Ann E. Nelson🇺🇸 · Devin G.E. Walker🇺🇸

    We examine a model with multiple scalar fields to see whether it is possible to reduce the fine- tuning of the SM Higgs mass without introducing low scale top partners. Our approach may be regarded as a generalization of the condition proposed by Veltman, who attempted to predict the Higgs mass using the criterion that the various low energy contributions to the quadratic divergence of the Higgs mass cancel. Although the Veltman condition predicts the wrong Higgs mass in the Standard Model, it can still be adapted to extended Higgs sectors. Furthermore, theories with additional Higgs bosons can lead to suppressed Yukawa couplings of the top quark to the 125 GeV Higgs, making the associated one-loop divergence smaller. Here, we review possible extensions of the Standard Model where the Veltman condition could be realized, and study in detail one minimal model with two extra scalar fields. For this model and for a cutoff of 5 TeV, we show that the overall fine-tuning can be considerably lowered without introducing low-scale Landau poles, albeit the Higgs sector will be strongly coupled at the cutoff. Models where the top Yukawa coupling is reduced, in particular, will be within the reach of the upcoming LHC searches.

    hep-phPRD(2018)·2 citations
15. 15*

    Updated Constraints on Non-Standard Interactions from Global Analysis of Oscillation Data

    Ivan Esteban🇪🇸 · M.C. Gonzalez-Garcia🇪🇸 · Michele Maltoni🇪🇸 · Ivan Martinez-Soler🇪🇸 · Jordi Salvado🇪🇸

    We quantify our present knowledge of the size and flavor structure of non-standard neutrino interactions which affect the matter background in the evolution of solar, atmospheric, reactor and long-baseline accelerator neutrinos as determined by a global analysis of oscillation data - both alone and in combination with the results on coherent neutrino-nucleus scattering from the COHERENT experiment. We consider general neutral current neutrino interactions with quarks whose lepton-flavor structure is independent of the quark type. We study the dependence of the allowed ranges of non-standard interaction coefficients, the status of the LMA-D solution, and the determination of the oscillation parameters on the relative strength of the non-standard couplings to up and down quarks. Generically we find that the conclusions are robust for a broad spectrum of up-to-down strengths, and we identify and quantify the exceptional cases related to couplings whose effect in neutrino propagation in the Earth or in the Sun is severely suppressed. As a result of the study we provide explicit constraints on the effective couplings which parametrize the non-standard Earth matter potential relevant for long-baseline experiments.

    hep-phastro-ph.HEhep-exJHEP(2018)·223 citations
16. 16*

    Finite-volume correction on the hadronic vacuum polarization contribution to muon g-2 in lattice QCD

    Taku Izubuchi🇺🇸 · Yoshinobu Kuramashi🇯🇵 · Christoph Lehner🇺🇸 · Eigo Shintani (PACS collaboration)🇯🇵

    We study the finite-volume correction on the hadronic vacuum polarization contribution to the muon g-2 ($a_{\mu }^{\mathrm{hvp}}$) in lattice QCD at (near) physical pion mass using two different volumes: $(5.4\mathrm{fm}{)}^4$ and $(8.1\mathrm{fm}{)}^4$. We use an optimized AMA technique for noise reduction on $N_f=2+1$ PACS gauge configurations with stout-smeared clover-Wilson fermion action and Iwasaki gauge action at a single lattice cut-off $a^{-1}=2.33$ GeV. The calculation is performed for the quark-connected light-quark contribution in the isospin symmetric limit. We take into account the effects of backward state propagation by extending a temporal boundary condition. In addition we study a quark-mass correction to tune to the exactly same physical pion mass on different volume and compare those correction with chiral perturbation. We find $10(26)\times 10^{-10}$ difference for light quark $a_{\mu }^{\mathrm{hvp}}$ between $(5.4\mathrm{fm}{)}^4$ and $(8.1\mathrm{fm}{)}^4$ lattice in 146 MeV pion.

    ↳ hep-lathep-phPRD(2018)·15 citations
17. 17*

    Resolving the $\Lambda$ hypernuclear overbinding problem in pionless effective field theory

    Lorenzo Contessi🇮🇱 · Nir Barnea🇮🇱 · Avraham Gal🇮🇱

    We address the $\Lambda$-hypernuclear `overbinding problem' in light hypernuclei which stands for a 1--3 MeV excessive $\Lambda$ separation energy calculated in ${}_{\Lambda }^5$He. This problem arises in most few-body calculations that reproduce ground-state $\Lambda$ separation energies in the lighter $\Lambda$ hypernuclei within various hyperon-nucleon interaction models. Recent pionless effective field theory nuclear few-body calculations are extended in this work to $\Lambda$ hypernuclei. At leading order, the $\Lambda N$ low-energy constants are associated with $\Lambda N$ scattering lengths and the $\Lambda NN$ low-energy constants are fitted to $\Lambda$ separation energies ($B_{\Lambda }^{\exp }$) for $A\le 4$. The resulting pionless-EFT interaction reproduces in few-body stochastic variational method calculations the reported value $B_{\Lambda }^{\exp }{(}_{\Lambda }^5$He)=3.12$\pm$0.02 MeV within a fraction of MeV over a broad range of momentum-space cut-off parameters. Possible consequences and extensions to heavier hypernuclei and to neutron-star matter are discussed.

    ↳ nucl-thhep-phnucl-exPRL(2018)·43 citations
18. 18*

    Lepton Flavour Universality tests in $B$ decays as a probe for New Physics

    Christoph Langenbruch (for the LHCb collaboration)🇩🇪

    In the Standard Model (SM), the coupling of the electroweak gauge bosons to the leptons is lepton flavour universal. Tests of this property constitute sensitive probes for new physics models that violate lepton flavour universality. Recent tests of lepton universality in rare $b\to s\ell \ell$ decays and semileptonic $b\to c\tau {\bar{\nu }}_{\tau }$ transitions have shown some tensions with the precise SM predictions. These proceedings summarise the latest results on lepton flavour universality from the LHCb experiment.

    ↳ hep-exhep-ph2 citations
19. 19*

    Improved limit on axion-like particles from gamma-ray data on Perseus cluster

    D. Malyshev🇩🇪 · A. Neronov🇨🇭 · D. Semikoz🇫🇷 · A. Santangelo🇩🇪 · J. Jochum🇩🇪

    Coupling of axion-like particles (ALPs) to photons in the presence of background magnetic field affects propagation of gamma-rays through magnetized environments. This results in modification in the gamma-ray spectra of sources in or behind galaxy clusters. We search for the ALP induced effects in the Fermi/LAT and MAGIC telescope spectra of the radio galaxy NGC 1275 embedded in Perseus galaxy cluster. We report an order-of-magnitude improved upper limit on the ALP-photon coupling constant in the 0.1-10 neV mass range from non-detection of the ALP imprints on the gamma-ray spectra. The improved upper limit extends into the coupling range in which the ALP particles could form the dark matter. We estimate the sensitivity improvements for the ALP search achievable with extension of the measurements to lower and higher energies with e-ASTROGAM and CTA and show that the gamma-ray probe of ALPs with masses in $10^{-11}-10^{-7}$ eV range will be have order-of-magnitude better sensitivity compared to ground-based experiment IAXO.

    ↳ astro-ph.HEhep-ph19 citations
20. 20*

    The Conformal Bootstrap: Theory, Numerical Techniques, and Applications

    David Poland🇺🇸 · Slava Rychkov🇫🇷 · Alessandro Vichi🇨🇭

    Conformal field theories have been long known to describe the fascinating universal physics of scale invariant critical points. They describe continuous phase transitions in fluids, magnets, and numerous other materials, while at the same time sit at the heart of our modern understanding of quantum field theory. For decades it has been a dream to study these intricate strongly coupled theories nonperturbatively using symmetries and other consistency conditions. This idea, called the conformal bootstrap, saw some successes in two dimensions but it is only in the last ten years that it has been fully realized in three, four, and other dimensions of interest. This renaissance has been possible both due to significant analytical progress in understanding how to set up the bootstrap equations and the development of numerical techniques for finding or constraining their solutions. These developments have led to a number of groundbreaking results, including world record determinations of critical exponents and correlation function coefficients in the Ising and $O(N)$ models in three dimensions. This article will review these exciting developments for newcomers to the bootstrap, giving an introduction to conformal field theories and the theory of conformal blocks, describing numerical techniques for the bootstrap based on convex optimization, and summarizing in detail their applications to fixed points in three and four dimensions with no or minimal supersymmetry.

    ↳ hep-thcond-mat.stat-mechcond-mat.str-elhep-lat+1RMP(2019)·928 citations
21. 21*

    Heavy decaying dark matter and IceCube high energy neutrinos

    M.Kachelriess🇳🇴 · O.E.Kalashev🇷🇺 · M.Yu.Kuznetsov🇷🇺

    We examine the hypothesis of decaying heavy dark matter (HDM) in the context of the IceCube highest energy neutrino events and recent limits on the diffuse flux of high-energy photons. We consider dark matter (DM) particles $X$ of mass $10^6\le M_X\le 10^{16}$ GeV decaying on tree level into $X\to \nu \bar{\nu }$, $X\to e^{+}{e}^{-}$ and $X\to q\bar{q}$. The full simulation of hadronic and electroweak decay cascades and the subsequent propagation of the decay products through the interstellar medium allows us to determine the permitted values of $M_X$. We show that for leptonic decay channels it is possible to explain the IceCube highest energy neutrino signal without overproducing high-energy photons for $M_X\lesssim 5.5\cdot 10^7$ GeV and $1.5\cdot 10^8\lesssim M_X\lesssim 1.5\cdot 10^9$ GeV, while hadronic decays contradict the gamma-ray limits for almost the whole range of $M_X$ values considered. The leptonic hypothesis can be probed by operating and planned gamma-ray observatories. For instance, the currently upgrading Carpet experiment will be capable to test a significant part of the remaining parameter window within one year of observation.

    ↳ astro-ph.HEhep-phPRD(2018)·99 citations
22. 22*

    S- and p-wave structure of $S=-1$ meson-baryon scattering in the resonance region

    D. Sadasivan🇺🇸 · M. Mai🇺🇸 · M. Doring🇺🇸

    We perform a simultaneous analysis of s- and p-waves of the $S=-1$ meson-baryon scattering amplitude using all low-energy experimental data. For the first time, differential cross section data are included for chiral unitary coupled-channel models. From this model s- and p-wave amplitudes are extracted and we observe both well-known $I(J^P)=0(1/2^{-})$ s-wave states as well as a new $I(J^P)=1(1/2^{+})$ state absent in quark models and lattice QCD results. Multiple statistical and phenomenological tests suggest that, while the data clearly require an $I=1$ p-wave resonance, the new state just accounts for the absence of the decuplet $\Sigma (1385)3/2^{+}$ in the model.

    ↳ nucl-thhep-phnucl-exPLB(2019)·31 citations
23. 23*

    Neutrino Emissivity in the Quark-Hadron Mixed Phase

    William M. Spinella🇺🇸 · Fridolin Weber🇺🇸 · Milva G. Orsaria🇦🇷 · Gustavo A. Contrera🇦🇷

    In this work we investigate the effect a crystalline quark-hadron mixed phase can have on the neutrino emissivity from the cores of neutron stars. To this end we use relativistic mean-field equations of state to model hadronic matter and a nonlocal extension of the three-flavor Nambu-Jona-Lasinio model for quark matter. Next we determine the extent of the quark-hadron mixed phase and its crystalline structure using the Glendenning construction, allowing for the formation of spherical blob, rod, and slab rare phase geometries. Finally we calculate the neutrino emissivity due to electron-lattice interactions utilizing the formalism developed for the analogous process in neutron star crusts. We find that the contribution to the neutrino emissivity due to the presence of a crystalline quark-hadron mixed phase is substantial compared to other mechanisms at fairly low temperatures ($\lesssim 10^9$ K) and quark fractions ($\lesssim 30\%$), and that contributions due to lattice vibrations are insignificant compared to static-lattice contributions. There are a number of open issues that need to be addressed in a future study on the neutrino emission rates caused by electron-quark blob bremsstrahlung. Chiefly among them are the role of collective oscillations of matter, electron band structures, and of gaps at the boundaries of the Brillouin zones on bremsstrahlung, as discussed in the summary section of this paper. We hope this paper will stimulate studies addressing these issues.

    ↳ nucl-thastro-ph.HEhep-phUniverse(2018)·12 citations
24. 24*

    Particle Physics and the Cosmic Microwave Background

    John E. Carlstrom🇺🇸 · Thomas M. Crawford🇺🇸 · Lloyd Knox🇺🇸

    Temperature and polarization variations across the microwave sky include the fingerprints of quantum fluctuations in the early universe. They may soon reveal physics at unprecedented energy scales.

    ↳ astro-ph.COgr-qchep-phPhys.Today(2015)·2 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.