Wed·Sep 27, 2017Wednesday·September 27, 2017

1. 01*

   Trilinear Higgs coupling determination via single-Higgs differential measurements at the LHC

   Fabio Maltoni🇧🇪 · Davide Pagani🇩🇪 · Ambresh Shivaji🇧🇪 · Xiaoran Zhao🇧🇪

   We study one-loop effects induced by an anomalous Higgs trilinear coupling on total and differential rates for the $H\to 4\ell$ decay and some of the main single-Higgs production channels at the LHC, namely, VBF, $VH$, $t\bar{t}H$ and $tHj$. Our results are based on a public code that calculates these effects by simply reweighting samples of Standard-Model-like events for a given production channel. For $VH$ and $t\bar{t}H$ production, where differential effects are particularly relevant, we include Standard Model electroweak corrections, which have similar sizes but different kinematic dependences. Finally, we study the sensitivity of future LHC runs to determine the trilinear coupling via inclusive and differential measurements, considering also the case where the Higgs couplings to vector bosons and the top quark is affected by new physics. We find that the constraints on the couplings and the relevance of differential distributions critically depend on the expected experimental and theoretical uncertainties.

   hep-phhep-exEPJC(2017)·154 citations
2. 02*

   Precision measurements for the Higgsploding Standard Model

   Valentin V. Khoze🇬🇧 · Joey Reiness🇬🇧 · Michael Spannowsky🇬🇧 · Philip Waite🇬🇧

   Higgsplosion is the mechanism that leads to exponentially growing decay rates of highly energetic particles into states with very high numbers of relatively soft Higgs bosons. In this paper we study quantum effects in the presence of Higgsplosion. First, we provide a non-perturbative definition of Higgsplosion as a resolved short-distance singularity of quantum propagators at distances shorter than the inverse Higgsplosion energy scale, $E_{\ast }$. We then consider quantum effects arising from loops in perturbation theory with these propagators on internal lines. When the loop momenta exceed the Higgsplosion scale $E_{\ast }$, the theory dynamics deviates from what is expected in the standard QFT settings without Higgsplosion. The UV divergences are automatically regulated by the Higgsplosion scale, leading to the change of slopes for the running couplings at the RG scales $\mu >E_{\ast }$. Thus, the theory becomes asymptotically safe. Further, we find that the finite parts are also modified and receive power-suppressed corrections in $1/E_{\ast }^2$. We use these results to compute a set of precision observables for the Higgsploding Standard Model. These and other precision observables could provide experimental evidence and tests for the existence of Higgsplosion in particle physics.

   hep-phhep-thJ.Phys.G(2019)·18 citations
3. 03*

   Fast Neutrino Flavor Conversion as Oscillations in a Quartic Potential

   Basudeb Dasgupta (1)🇮🇳 · Manibrata Sen (1) ((1) Tata Inst.)🇮🇳

   Neutrinos in dense environments undergo collective pair conversions ${\nu }_e{\bar{\nu }}_e\leftrightarrow {\nu }_x{\bar{\nu }}_x$, where $x$ is a non-electron flavor, due to forward scattering off each other that may be a crucial ingredient for supernova explosions. Depending on the flavor-dependent local angular distributions of the neutrino fluxes, the conversion rate can be "fast", i.e., of the order $\mu =\sqrt{2}{G}_F{n}_{\nu }$, which can far exceed the usual neutrino oscillation frequency $\omega =\Delta m^2/(2E)$. Until now, this surprising nonlinear phenomenon has only been understood in the linear regime and explored further using numerical experiments. We present an analytical treatment of the simplest system that exhibits fast conversions, and show that the conversion can be understood as the dynamics of a particle rolling down in a quartic potential governed dominantly by $\mu$, but seeded by slower oscillations.

   hep-phastro-ph.HEPRD(2018)·73 citations
4. 04*

   Generalizing Minimal Dark Matter: Millicharge or Decay

   Eugenio Del Nobile🇮🇹

   The Minimal Dark Matter framework classifies viable Dark Matter (DM) candidates that are obtained by simply augmenting the Standard Model of particle interactions with a new multiplet, without adding new ad hoc symmetries to make the DM stable. The model has no free parameters and is therefore extremely predictive; moreover, recent studies singled out a Majorana $SU(2{)}_{\text{L}}$ quintuplet as the only viable candidate. The model can be constrained by both direct and indirect DM searches, with present time gamma-ray line searches in the Galactic Center being particularly sensitive. It is therefore timely to critically review this paradigm and point out possible generalizations. We propose and explore two distinct directions. One is to lower the cutoff of the model, which was originally fixed at the Planck scale, to allow for decays of the DM quintuplet. We analyze the decay spectrum of this candidate in detail and show that gamma-ray data constrain the cutoff to lie above the GUT scale. Another possibility is to abandon the assumption of DM electric neutrality in favor of absolutely stable, millicharged DM candidates. We explicitly study a few examples, and find that a Dirac $SU(2{)}_{\text{L}}$ triplet is the candidate least constrained by indirect searches.

   hep-phastro-ph.COPoS(2017)·0 citations
5. 05*

   Direct detection signals of dark matter with magnetic dipole moment

   Eugenio Del Nobile🇮🇹

   A neutral dark matter (DM) particle with a magnetic dipole moment has a very different direct detection phenomenology with respect to standard candidates. This is due to the peculiar functional form of the differential cross section for scattering with nuclei. Such a candidate could be a bound state of charged particles, as the neutron or an atom, or a fundamental particle coupled to heavier charged states, much like a Dirac neutrino. We analyze here the direct detection signals of DM with magnetic dipole moment, both the recoil rate and its modulation, and show that they are very different from those expected in standard scenarios. For this candidate, contrary to the common lore, the time of maximum signal depends on the recoil energy as well as on the target material. The observation of different modulations by experiments employing different targets would be a strong indication in favor of this type of DM particles.

   hep-phastro-ph.COPoS(2017)·7 citations
6. 06*

   The importance of calorimetry for highly-boosted jet substructure

   Evan Coleman🇺🇸 · Marat Freytsis🇺🇸 · Andreas Hinzmann🇩🇪 · Meenakshi Narain🇺🇸 · Jesse Thaler🇺🇸 · Nhan Tran🇺🇸 · Caterina Vernieri🇺🇸

   Jet substructure techniques are playing an essential role in exploring the TeV scale at the Large Hadron Collider (LHC), since they facilitate the efficient reconstruction and identification of highly-boosted objects. Both for the LHC and for future colliders, there is a growing interest in using jet substructure methods based only on charged-particle information. The reason is that silicon-based tracking detectors offer excellent granularity and precise vertexing, which can improve the angular resolution on highly-collimated jets and mitigate the impact of pileup. In this paper, we assess how much jet substructure performance degrades by using track-only information, and we demonstrate physics contexts in which calorimetry is most beneficial. Specifically, we consider five different hadronic final states - W bosons, Z bosons, top quarks, light quarks, gluons - and test the pairwise discrimination power with a multi-variate combination of substructure observables. In the idealized case of perfect reconstruction, we quantify the loss in discrimination performance when using just charged particles compared to using all detected particles. We also consider the intermediate case of using charged particles plus photons, which provides valuable information about neutral pions. In the more realistic case of a segmented calorimeter, we assess the potential performance gains from improving calorimeter granularity and resolution, comparing a CMS-like detector to more ambitious future detector concepts. Broadly speaking, we find large performance gains from neutral-particle information and from improved calorimetry in cases where jet mass resolution drives the discrimination power, whereas the gains are more modest if an absolute mass scale calibration is not required.

   hep-phhep-exJINST(2018)·34 citations
7. 07*

   A meson-baryon molecular interpretation for some ${\Omega }_c$ excited baryons

   Glòria Montaña🇪🇸 · Albert Feijoo🇪🇸 · Àngels Ramos🇪🇸

   We explore the possibility that some of the five narrow ${\Omega }_c$ resonances recently observed at LHCb could correspond to pentaquark states, structured as meson-baryon bound states or molecules. The interaction of the low-lying pseudoscalar mesons with the ground-state baryons in the charm $+1$, strangeness $-2$ and isospin 0 sector is built from t-channel vector meson exchange, using effective Lagrangians. The resulting s-wave coupled-channel unitarized amplitudes show the presence of two structures with similar masses and widths to those of the observed ${\Omega }_c(3050{)}^0$ and ${\Omega }_c(3090{)}^0$. The identification of these resonances with the meson-baryon bound states found in this work would also imply assigning the values $1/2^{-}$ for their spin-parity. An experimental determination of the spin-parity of the ${\Omega }_c(3090{)}^0$ would help in disentangling its structure, as the quark-based models predict its spin-parity to be either $3/2^{-}$ or $5/2^{-}$.

   hep-phnucl-thEPJA(2018)·76 citations
8. 08*

   On the $ZH\eta$ vertex in the simplest Little Higgs Model

   Shi-Ping He🇨🇳 · Ying-nan Mao🇨🇳 · Chen Zhang🇹🇼 · Shou-hua Zhu🇨🇳

   The issue of deriving $ZH\eta$ vertex in the simplest Little Higgs (SLH) model is revisited. Special attention is paid to the treatment of non-canonically-normalized scalar kinetic matrix and vector-scalar two-point transitions. We elucidate a general procedure to diagonalize a general vector-scalar system in gauge theories and apply it to the case of SLH. The resultant $ZH\eta$ vertex is found to be different from those which have already existed in the literature for a long time. We also present an understanding of this issue from an effective field theory viewpoint.

   hep-phPRD(2018)·9 citations
9. 09*

   Analysis of top quark pair production signal from neutral 2HDM Higgs bosons at LHC

   Majid Hashemi🇮🇷 · Mahbobeh Jafarpour🇮🇷

   In this paper, the top quark pair production events are analyzed as a source of neutral Higgs bosons of two Higgs doublet model type I at LHC. The production mechanism is $pp\to H/A\to t\bar{t}$ assuming a fully hadronic final state through $t\to Wb\to jjb$. In order to distinguish the signal from the main background which is the standard model $t\bar{t}$, we benefit from the fact that the top quarks in signal events acquire a large Lorentz boost due to the heavy neutral Higgs boson. This feature leads to three collinear jets (a fat jet) which is a discriminating tool for identification of the top quarks from the Higgs boson resonances. Events with two identified top jets are selected and the invariant mass of the top pair is calculated for both signal and background. It is shown that the low $\tan \beta$ region has still some parts which can be covered by this analysis and has not been excluded yet by flavor physics data.

   hep-phAdv.High Energy Phys.(2018)·1 citation
10. 10*

    Azimuthal angle correlations at large rapidities: revisiting density variation mechanism

    E. Gotsman (Tel Aviv U.)🇮🇱 · E. Levin (Tel Aviv U./UTFSM)🇮🇱

    In the paper we discuss the angular correlation present in hadron-hadron collisions at large rapidity difference ($\text{bas}{y}_{12}\gg 1$). We find that in the CGC/saturation approach the largest contribution stems from the density variation mechanism. Our principal results are that the odd Fourier harmonics($v_{2n+1}$), decrease substantially as function of $y_{12}$, while the even harmonics ($v_{2n}$ ), increase considerably with a growth of $y_{12}$.

    hep-phEPJC(2017)·3 citations
11. 11*

    Back-to-back heavy quark pair production in Semi-inclusive DIS

    Guang-Peng Zhang🇨🇳

    The one-loop correction to heavy quark pair back-to-back production in unpolarized semi-inclusive deep inelastic scattering is given in this work in the framework of transverse momentum dependent(TMD) factorization. Both unpolarized and linearly polarized TMD gluon distribution functions are taken into account. A subtraction method based on diagram expansion is used to get finite hard coefficients. It is found the soft and collinear divergences of one-loop amplitude is proportional to tree level ones and can be expressed through several basic scalar triangle and bubble integrals. The subtraction of these divergences is spin independent. Beyond tree level an additional soft factor related to final heavy quark pair must be added into the factorization formula. This soft factor affects the azimuthal angle distribution of virtual photon in a nonperturbative way. Integrating over virtual photon azimuthal angle we construct three weighted cross sections, which depend on only three additional integrated soft factors. These weighted cross sections can be used to extract linearly polarized gluon distribution function. In addition, lepton azimuthal angle is unintegrated in this work, which provides more observables. All hard coefficients relevant to lepton and virtual photon azimuthal angle distributions are given at one-loop level.

    hep-phJHEP(2017)·10 citations
12. 12*

    The Roper resonance: a genuine quark state or a dynamically generated structure?

    B. Golli🇸🇮 · H. Osmanović🇧🇦 · S. Širca🇸🇮 · A. Švarc🇭🇷

    In view of the recent results of lattice QCD simulation in the P11 partial wave that has found no clear signal for the three-quark Roper state we investigate a different mechanism for the formation of the Roper resonance in a coupled channel approach including the $\pi N$, $\pi \Delta$ and $\sigma N$ channels. We fix the pion-baryon vertices in the underlying quark model while the $s$-wave sigma-baryon interaction is introduced phenomenologically with the coupling strength, the mass and the width of the $\sigma$ meson as free parameters. The Laurent-Pietarinen expansion is used to extract the information about the $S$-matrix pole. The Lippmann-Schwinger equation for the $K$ matrix with a separable kernel is solved to all orders. For sufficiently strong $\sigma NN$ coupling the kernel becomes singular and a quasi-bound state emerges at around 1.4~GeV, dominated by the $\sigma N$ component and reflecting itself in a pole of the $S$-matrix. The alternative mechanism involving a $(1s{)}^{2}2s$ quark resonant state is added to the model and the interplay of the dynamically generated state and the three-quark resonant state is studied. It turns out that for the mass of the three-quark resonant state above 1.6~GeV the mass of the resonance is determined solely by the dynamically generated state, nonetheless, the inclusion of the three-quark resonant state is imperative to reproduce the experimental width and the modulus of the resonance pole.

    hep-phnucl-thPRC(2018)·18 citations
13. 13*

    Neutrino mass matrices with three or four vanishing cofactors and non diagonal charged lepton sector

    S. Dev🇮🇳 · Desh Raj🇮🇳 · Radha Raman Gautam🇮🇳

    We investigate the texture structures of lepton mass matrices with four (five) non-zero elements in the charged lepton mass matrix and three (four) vanishing cofactors in the neutrino mass matrix. Using weak basis transformations, all possible textures for three and four vanishing cofactors in $M_{\nu }$ are grouped into 7 classes and predictions for the unknown parameters such as the Dirac CP violating phase and the effective Majorana mass for the phenomenologically allowed textures have been obtained. We, also, illustrate how such texture structures can be realized using discrete Abelian flavor symmetries.

    hep-phPRD(2017)·4 citations
14. 14*

    Light Higgs Boson from a Pole Attractor

    Oleksii Matsedonskyi🇩🇪 · Marc Montull🇩🇪

    We propose a new way of explaining the observed Higgs mass, within the cosmological relaxation framework. The key feature distinguishing it from other scanning scenarios is that the scanning field has a non-canonical kinetic term, whose role is to terminate the scan around the desired Higgs mass value. We propose a concrete realisation of this idea with two new singlet fields, one that scans the Higgs mass, and another that limits the time window in which the scan is possible. Within the provided time period, the scanning field does not significantly evolve after the Higgs field gets close to the Standard Model value, due to particle production friction.

    hep-phPRD(2018)·8 citations
15. 15*

    Note on X(3872) production at hadron colliders and its molecular structure

    Miguel Albaladejo🇪🇸 · Feng-Kun Guo🇨🇳 · Christoph Hanhart🇩🇪 · Ulf-G. Meißner🇩🇪 · Juan Nieves🇪🇸 · Andreas Nogga🇩🇪 · Zhi Yang🇩🇪

    The production of the X(3872) as a hadronic molecule in hadron colliders is clarified. We show that the conclusion of Bignamini et al., Phys. Rev. Lett. 103 (2009) 162001, that the production of the X(3872) at high $p_T$ implies a non-molecular structure, does not hold. In particular, using the well understood properties of the deuteron wave function as an example, we identify the relevant scales in the production process.

    hep-phhep-exnucl-thCPC(2017)·59 citations
16. 16*

    A Portalino to the Dark Sector

    Martin Schmaltz (BU)🇺🇸 · Neal Weiner (CCPP, NYU)🇺🇸

    "Portal" models that connect the Standard Model to a Dark Sector allow for a wide variety of scenarios beyond the simplest WIMP models. Kinetic mixing of gauge fields in particular has allowed a broad range of new ideas. However, the models that evade CMB constraints are often non-generic, with new mass scales and operators to split states and suppress indirect detection signals. Models with a "portalino", a neutral fermion that marries a linear combination of a standard model neutrino and dark sector fermion and carries a conserved quantum number, can be simpler. This is especially interesting for interacting dark sectors; then the unmarried linear combination which we identify as the standard model neutrino inherits these interactions too, and provides a new, effective interaction between the dark sector and the standard model. These interactions can be simple $Z^{\prime }$ type interactions or lepton-flavor changing. Dark matter freezes out into neutrinos, thereby evading CMB constraints, and conventional direct detection signals are largely absent. The model offers different signals, however. The "portalino" mechanism itself predicts small corrections to the standard model neutrino couplings as well as the possibility of discovering the portalino particle in collider experiments. Possible cosmological and astroparticle signatures include monochromatic neutrino signals from annihilation, spectral features in high energy CR neutrinos as well as conventional signals of additional light species and dark matter interactions.

    hep-phJHEP(2019)·23 citations
17. 17*

    Fermionic Glauber Operators and Quark Reggeization

    Ian Moult🇺🇸 · Mikhail P. Solon🇺🇸 · Iain W. Stewart🇺🇸 · Gherardo Vita🇺🇸

    We derive, in the framework of soft-collinear effective field theory (SCET), a Lagrangian describing the $t$-channel exchange of Glauber quarks in the Regge limit. The Glauber quarks are not dynamical, but are incorporated through non-local fermionic potential operators. These operators are power suppressed in $|t|/s$ relative to those describing Glauber gluon exchange, but give the first non-vanishing contributions in the Regge limit to processes such as $q\bar{q}\to gg$ and $q\bar{q}\to \gamma \gamma$. They therefore represent an interesting subset of power corrections to study. The structure of the operators, which describe certain soft and collinear emissions to all orders through Wilson lines, is derived from the symmetries of the effective theory combined with constraints from power and mass dimension counting, as well as through explicit matching calculations. Lightcone singularities in the fermionic potentials are regulated using a rapidity regulator, whose corresponding renormalization group evolution gives rise to the Reggeization of the quark at the amplitude level and the BFKL equation at the cross section level. We verify this at one-loop, deriving the Regge trajectory of the quark in the $3$ color channel, as well as the leading logarithmic BFKL equation. Results in the $\bar{6}$ and $15$ color channels are obtained by the simultaneous exchange of a Glauber quark and a Glauber gluon. SCET with quark and gluon Glauber operators therefore provides a framework to systematically study the structure of QCD amplitudes in the Regge limit, and derive constraints on higher order amplitudes.

    hep-phhep-thnucl-thJHEP(2018)·39 citations
18. 18*

    Lepton Number Violation, Lepton Flavour Violation and Baryogenesis in Left-Right Symmetric Model

    Happy Borgohain🇮🇳 · Mrinal Kumar Das🇮🇳

    We did a model independent phenomenological study of baryogenesis via leptogenesis, neutrinoless double beta decay (NDBD) and charged lepton flavour violation (CLFV) in a generic left-right symmetric model (LRSM) where neutrino mass originates from the type I + type II seesaw mechanism. We studied the new physics contributions to NDBD coming from the left-right gauge boson mixing and the heavy neutrino contribution within the framework of LRSM. We have considered the mass of the RH gauge boson to be specifically 5 TeV, 10 TeV and 18 TeV and studied the effects of the new physics contributions on the effective mass and baryogenesis and compared with the current experimental limit. We tried to correlate the cosmological BAU from resonant leptogenesis with the low energy observables, notably, NDBD and LFV with a view to finding a common parameter space where they coexists.

    hep-phastro-ph.COnucl-thPRD(2017)·16 citations
19. 19*

    Sub-leading correction of two-gluon rapidity correlations of strong colour field

    Ye-Yin Zhao🇨🇳 · Ming-Mei Xu🇨🇳 · Heng-Ying Zhang🇨🇳 · Yuan-Fang Wu🇨🇳

    In the framework of Color Glass Condensate (CGC) effective field theory (EFT), we calculate two-gluon rapidity correlations in the leading and sub-leading orders of $p_{\perp }/Q_s$. In the leading order, both short- and long-range rapidity correlations are enhanced. In contrast, the contribution of sub-leading order is mainly short range quantum correlations. It is much smaller than that of the leading one, but is not negligible. Transverse momentum dependence of rapidity correlation shows that the leading order is sensitive to the saturation momentum of two incident particles, but the sub-leading one is not.

    ↳ nucl-thhep-ph4 citations
20. 20*

    On ${}^{146}$Nd, ${}^{144}$Sm and other unexplored 2$\beta$ decay isotopes

    Francesco Nozzoli🇮🇹

    ${}^{146}$Nd is one of only four (over a total of 35 existing) 2${\beta }^{-}$ decay isotope candidates whose half-lives currently lack experimental limits. The $\alpha$ activity of the ${}^{146}$Sm daughter nuclide allows placement of limits on the 2$\beta$ decay using the ${}^{146}$Nd/${}^{142}$Nd abundance ratio ($T_{1/2}^{\beta \beta }\text{gsim}3\times 10^9$ yr) or direct search for ${}^{146}$Sm with accelerator mass spectrometers ($T_{1/2}^{\beta \beta }\text{gsim}4.5\times 10^{19}$ yr). With a similar approach, a modest ($\sim$ Gyr) first limit on half-lives for the other unexplored $2\beta$ unstable isotopes and competitive limits (few $10^{13}$yr) for ${}^{98}$Mo and ${}^{122}$Sn are also given. Finally, it is shown how the limit $T_{1/2}^{0\nu ϵ{\beta }^{+}}\text{gsim}10^{15}$ yr for the unexplored ${}^{144}$Sm $0\nu ϵ{\beta }^{+}$ decay may be obtained from the data of a GSO crystal scintillator.

    ↳ nucl-exhep-phnucl-thPRC(2018)·7 citations
21. 21*

    A new mechanism for generating particle number asymmetry through interactions

    Takuya Morozumi (Hiroshima-U)🇯🇵 · Keiko I. Nagao (Okayama University of Science)🇯🇵 · Apriadi Salim Adam (Hiroshima-U)🇯🇵 · Hiroyuki Takata (TSPU)🇷🇺

    A new mechanism for generating particle number asymmetry (PNA) has been developed. This mechanism is realized with a Lagrangian including a complex scalar field and a neutral scalar field. The complex scalar carries U(1) charge which is associated with the PNA. It is written in terms of the condensation and Green's function, which is obtained with two-particle irreducible (2PI) closed time path (CTP) effective action (EA). In the spatially flat universe with a time-dependent scale factor, the time evolution of the PNA is computed. We start with an initial condition where only the condensation of the neutral scalar is non-zero. The initial condition for the fields is specified by a density operator parameterized by the temperature of the universe. With the above initial conditions, the PNA vanishes at the initial time and later it is generated through the interaction between the complex scalar and the condensation of the neutral scalar. We investigate the case that both the interaction and the expansion rate of the universe are small and include their effects up to the first order of the perturbation. The expanding universe causes the effects of the dilution of the PNA, freezing interaction and the redshift of the particle energy. As for the time dependence of the PNA, we found that PNA oscillates at the early time and it begins to dump at the later time. The period and the amplitude of the oscillation depend on the mass spectrum of the model, the temperature and the expansion rate of the universe.

    ↳ hep-thgr-qchep-phAdv.High Energy Phys.(2019)·3 citations
22. 22*

    Probing the dark matter-electron interactions via hydrogen-atmosphere pulsating white dwarfs

    Jia-Shu Niu🇨🇳 · Tianjun Li🇨🇳 · Weikai Zong🇨🇳 · Hui-Fang Xue🇨🇳 · Yang Wang🇨🇳

    In this work, we propose a novel scenario to probe the interactions between dark matter (DM) particles and electrons, via hydrogen-atmosphere pulsating white dwarfs (DAVs) in globular clusters. In this special configuration, the DM particles, which are predominantly captured by multiple scattering with the electrons in a DAV, would annihilate by pairs and provide extra energy source to the DAV. This mechanism slows down the natural cooling evolution which can be presented by the period variation rates of pulsation modes. The differences between the secular rates predicted by the precise asteroseismology and the secular rates obtained from observation can reveal the DM-electron interactions. An important observable has been proposed and corresponding estimations have been made. According to the estimation, if this scenario could be implemented in the near future, the potential sensitivity on $m_{\chi }$ (DM particle's mass) and ${\sigma }_{\chi ,e}$ (elastic scattering cross section between DM and electron) could be hopefully extended to a region $5\mathrm{GeV}\lesssim m_{\chi }\lesssim 10^4\mathrm{GeV}$ and ${\sigma }_{\chi ,e}\gtrsim 10^{-40}{\mathrm{cm}}^2$. Combining with indirect DM detection results, this could give us a cross check on the existence of such leptonphilic DM particles to some extent.

    ↳ astro-ph.HEastro-ph.SRhep-phPRD(2018)·9 citations
23. 23*

    Mixed Phase within the Multi-polytrope Approach to High Mass Twins

    David Alvarez-Castillo🇷🇺 · David Blaschke🇷🇺 · Stefan Typel🇩🇪

    We present a multi-polytrope approach to describe high-mass twins fulfilling chiral effective field theory estimations of the neutron star equation state and test it against the appearance of mixed phases at the hadron-quark interface. In addition, we discuss astrophysical applications of this method and expected future measurements that shall further constrain neutron star matter and the understanding of the QCD phase diagram.

    ↳ nucl-thastro-ph.HEhep-phAstron.Nachr.(2017)·7 citations
24. 24*

    Tests of Chameleon Gravity

    Clare Burrage🇬🇧 · Jeremy Sakstein🇺🇸

    Theories of modified gravity where light scalars with non-trivial self-interactions and non-minimal couplings to matter-chameleon and symmetron theories-dynamically suppress deviations from general relativity in the solar system. On other scales, the environmental nature of the screening means that such scalars may be relevant. The highly-nonlinear nature of screening mechanisms means that they evade classical fifth-force searches, and there has been an intense effort towards designing new and novel tests to probe them, both in the laboratory and using astrophysical objects, and by reinterpreting existing datasets. The results of these searches are often presented using different parametrizations, which can make it difficult to compare constraints coming from different probes. The purpose of this review is to summarize the present state-of-the-art searches for screened scalars coupled to matter, and to translate the current bounds into a single parametrization to survey the state of the models. Presently, commonly studied chameleon models are well-constrained but less commonly studied models have large regions of parameter space that are still viable. Symmetron models are constrained well by astrophysical and laboratory tests, but there is a desert separating the two scales where the model is unconstrained. The coupling of chameleons to photons is tightly constrained but the symmetron coupling has yet to be explored. We also summarize the current bounds on $f(R)$ models that exhibit the chameleon mechanism (Hu \& Sawicki models). The simplest of these are well constrained by astrophysical probes, but there are currently few reported bounds for theories with higher powers of $R$. The review ends by discussing the future prospects for constraining screened modified gravity models further using upcoming and planned experiments.

    ↳ astro-ph.COgr-qchep-phLiving Rev.Rel.(2018)·413 citations
25. 25*

    Effects of retarded electrical fields on observables sensitive to the high-density behavior of nuclear symmetry energy in heavy-ion collisions at intermediate energies

    Gao-Feng Wei🇨🇳 · Bao-An Li🇺🇸 · Gao-Chan Yong🇨🇳 · Li Ou🇨🇳 · Xin-Wei Cao🇨🇳 · Xu-Yang Liu🇨🇳

    Within the isospin- and momentum-dependent transport model IBUU11, we examine the relativistic retardation effects of electrical fields on the ${\pi }^{-}/{\pi }^{+}$ ratio and neutron-proton differential transverse flow in heavy-ion collisions at intermediate energies. Compared to the static Coulomb fields, the retarded electric fields of fast-moving charges are known to be anisotropic and the associated relativistic corrections can be significant. They are found to increase the number of energetic protons in the participant region at the maximum compression by as much as 25\% but that of energetic neutrons by less than 10\% in ${}^{197}$Au+${}^{197}$Au reactions at a beam energy of 400 MeV/nucleon. Consequently, more ${\pi }^{+}$ and relatively less ${\pi }^{-}$ mesons are produced, leading to an appreciable reduction of the ${\pi }^{-}/{\pi }^{+}$ ratio compared to calculations with the static Coulomb fields. Also, the neutron-proton differential transverse flow, as another sensitive probe of high-density symmetry energy, is also decreased appreciably due to the stronger retarded electrical fields in directions perpendicular to the velocities of fast-moving charges compared to calculations using the isotropic static electrical fields. Moreover, the retardation effects on these observables are found to be approximately independent of the reaction impact parameter.

    ↳ nucl-thhep-phPRC(2018)·10 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.