Wed·Nov 30, 2016Wednesday·November 30, 2016

1. 01*

   Phenomenological analysis of associated production of $Z^0+b$ in the $b\to J/\psi X$ decay channel at the LHC

   Jean-Philippe Lansberg🇫🇷 · Hua-Sheng Shao🇨🇭

   The ATLAS collaboration recently reported on the first observation of associated-production of a $Z^0$ boson with a $J/\psi$. We recently claimed that the corresponding yield of the {\it prompt} $J/\psi$ was dominated by double parton scatterings in the ATLAS acceptance with a somewhat small value of ${\sigma }_{\mathrm{eff}}$. We also found out that single parton scatterings were only dominant at large transverse momenta. We present here the first phenomenological analysis of another part of the ATLAS data sample, namely of a $Z^0$ boson plus a {\it non-prompt} $J/\psi$. Our study is performed at next-to-leading order in ${\alpha }_s$ and includes parton-shower effects via the {\sc\small MadGraph5_aMC@NLO} framework. We find out that the data, unlike the case of prompt $J/\psi +Z^0$, do not hint at significant DPS contributions. Owing to the current experimental and theoretical uncertainties, there is still a room for these but with a lower limit of ${\sigma }_{\mathrm{eff}}$ close to 5 mb. We stress the importance of QCD corrections to account for the ATLAS data.

   hep-phhep-exnucl-exnucl-thNPB(2017)·30 citations
2. 02*

   Phenomenology of on-shell Higgs production in the MSSM with complex parameters

   Stefan Liebler🇩🇪 · Shruti Patel🇩🇪 · Georg Weiglein🇩🇪

   A computation of inclusive cross sections for neutral Higgs boson production through gluon fusion and bottom-quark annihilation is presented in the MSSM with complex parameters. The predictions for the gluon-fusion process are based on an explicit calculation of the leading-order cross section for arbitrary complex parameters which is supplemented by higher-order corrections: massive top- and bottom-quark contributions at NLO QCD, in the heavy top-quark effective theory the top-quark contribution up to N${}^3$LO QCD including a soft expansion for the $\mathcal{C}\mathcal{P}$-even component of the light Higgs boson. For its $\mathcal{C}\mathcal{P}$-odd component and the heavy Higgs bosons the contributions are incorporated up to NNLO QCD. Two-loop electroweak effects are also incorporated, and SUSY QCD corrections at NLO are interpolated from the MSSM with real parameters. Finite wave function normalisation factors ensuring correct on-shell properties of the external Higgs bosons are incorporated from the code $\text{FeynHiggs}$. For the typical case of a strong admixture of the two heavy Higgs bosons it is demonstrated that squark effects are strongly dependent on the phases of the complex parameters. The remaining theoretical uncertainties for cross sections are discussed. The results have been implemented into an extension of the numerical code $\text{SusHi}$ called $\text{SusHiMi}$.

   hep-phEPJC(2017)·21 citations
3. 03*

   Constraining the monochromatic gamma-rays from dark matter annihilation by the LHC

   Arman Esmaili🇧🇷 · Sara Khatibi🇮🇷 · Mojtaba Mohammadi Najafabadi🇮🇷

   The installation of forward detectors in CMS and ATLAS turn the LHC to an effective photon-photon collider. The elastic scattering of the beam-protons via the emission of photons, which can be identified by tagging the intact protons in the forward detectors, provides a powerful diagnostic of the central production of new particles through photon-photon annihilation. In this letter we study the central production of dark matter particles and the potential of LHC to constrain the cross section of this process. By virtue of the crossing symmetry, this limit can immediately be used to constrain the production of monochromatic gamma-rays in dark matter annihilation, a smoking gun signal under investigation in indirect dark matter searches. We show that with the integrated luminosity $\mathcal{L}=30{\mathrm{fb}}^{-1}$ in LHC at center-of-mass energy $\sqrt{s}=$ 13 TeV, for dark matter masses $\sim (50-600)$ GeV, a model-independent constraint on the cross section of dark matter annihilation to monochromatic gamma-rays at the same order of magnitude as the current Fermi-LAT and the future limits from CTA, can be obtained.

   hep-phastro-ph.HEhep-exPRD(2017)·7 citations
4. 04*

   Double Higgs production at the 14 TeV LHC and the 100 TeV pp-collider

   Qing-Hong Cao🇨🇳 · Gang Li🇨🇳 · Bin Yan🇨🇳 · Dong-Ming Zhang🇨🇳 · Hao Zhang🇨🇳

   We consider effective Higgs boson couplings, including both the CP-even and CP-odd couplings, that affect Higgs boson pair production in this study. Through the partial wave analysis, we find that the process $gg\to hh$ is dominated by the $s$-wave component even at a 100~TeV $pp$-collider. Making use of the $s$-wave kinematics, we propose a cut efficiency function to mimic the collider simulation and obtain the potential of measuring Higgs effective couplings at the 14~TeV LHC with an integrated luminosity of $3000{\mathrm{fb}}^{-1}$ and at a 100 TeV $pp$-collider. Analytical expressions of the $2\sigma$ exclusion limits at the LHC and the $5\sigma$ discovery bands at the 100 TeV machine are given.

   hep-phhep-exPRD(2017)·67 citations
5. 05*

   Collider Phenomenology of the 3-3-1 Model

   Qing-Hong Cao🇨🇳 · Dong-Ming Zhang🇨🇳

   We study collider phenomenology of the so-called 331 model with $SU(3{)}_C\otimes SU(3{)}_L\otimes U(1{)}_X$ gauge structure at the large hadron collider, including single and double Higgs boson productions, Higgs boson rare decay, $Z^{\prime }$ boson production, new charged gauge boson pair production, and heavy quark pair production. We discuss all the possible collider signatures of new particle productions. Four benchmark 331 models, $\beta =\pm \sqrt{3}$ and $\beta =\pm 1/\sqrt{3}$, are studied in this work.

   hep-phhep-ex47 citations
6. 06*

   A New Flavor of Searches for Axion-Like Particles

   Eder Izaguirre🇺🇸 · Tongyan Lin🇺🇸 · Brian Shuve🇺🇸

   We propose new searches for axion-like particles (ALPs) produced in flavor-changing neutral current (FCNC) processes. This proposal exploits the often-overlooked coupling of ALPs to W bosons, leading to FCNC production of ALPs even in the absence of a direct coupling to fermions. Our proposed searches for resonant ALP production in decays such as $B\to K^{(\ast )}a,a\to \gamma \gamma$ and $K\to \pi a,a\to \gamma \gamma$ could greatly improve upon the current sensitivity to ALP couplings to Standard Model particles. We also determine analogous constraints and discovery prospects for invisibly decaying ALPs.

   hep-phhep-exPRL(2017)·218 citations
7. 07*

   Electroweak symmetry breaking and collider signatures in the next-to-minimal composite Higgs model

   Christoph Niehoff🇩🇪 · Peter Stangl🇩🇪 · David M. Straub🇩🇪

   We conduct a detailed numerical analysis of the composite pseudo-Nambu-Goldstone Higgs model based on the next-to-minimal coset $\text{SO}(6)/\text{SO}(5)\cong \text{SU}(4)/\text{Sp}(4)$, featuring an additional SM singlet scalar in the spectrum, which we allow to mix with the Higgs boson. We identify regions in parameter space compatible with all current experimental constraints, including radiative electroweak symmetry breaking, flavour physics, and direct searches at colliders. We find the additional scalar, with a mass predicted to be below a TeV, to be virtually unconstrained by current LHC data, but potentially in reach of run 2 searches. Promising indirect searches include rare semi-leptonic $B$ decays, CP violation in $B_s$ mixing, and the electric dipole moment of the neutron.

   hep-phJHEP(2017)·25 citations
8. 08*

   The branching ratio $\omega \to {\pi }^{+}{\pi }^{-}$ revisited

   C. Hanhart🇩🇪 · S. Holz🇩🇪 · B. Kubis🇩🇪 · A. Kupść🇸🇪 · A. Wirzba🇩🇪 · C. W. Xiao🇩🇪

   We analyze the most recent data for the pion vector form factor in the timelike region, employing a model-independent approach based on dispersion theory. We confirm earlier observations about the inconsistency of different modern high-precision data sets. Excluding the BaBar data, we find an updated value for the isospin-violating branching ratio $\mathcal{B}(\omega \to {\pi }^{+}{\pi }^{-})=(1.46\pm 0.08)\times 10^{-2}$. As a side result, we also extract an improved value for the pion vector or charge radius, $\sqrt{⟨r_V^2⟩}=0.6603(5)(4)\text{fm}$, where the first uncertainty is statistical as derived from the fit, while the second estimates the possible size of nonuniversal radiative corrections. In addition, we demonstrate that modern high-quality data for the decay ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\gamma$ will allow for an even improved determination of the transition strength $\omega \to {\pi }^{+}{\pi }^{-}$.

   hep-phhep-exnucl-exnucl-thEPJC(2017)·71 citations
9. 09*

   A Systematic Effective Operator Analysis of Semi-Annihilating Dark Matter

   Yi Cai🇦🇺 · Andrew Spray🇰🇷

   Semi-annihilation is a generic feature of dark matter theories stabilised by symmetries larger than a $Z_2$. It contributes to thermal freeze out, but is irrelevant for direct and collider searches. This allows semi-annihilating dark matter to avoid those limits in a natural way. We use an effective operator approach to make the first model-independent study of the associated phenomenology. We enumerate all possible operators that contribute to $2\to 2$ semi-annihilation up to dimension 6, plus leading terms at dimension 7. We find that when the only light states charged under the dark symmetry are dark matter, the model space is highly constrained. Only fifteen operators exist, and just two for single-component dark sectors. If there can be additional light, unstable "dark partner" states the possible phenomenology greatly increases, at the cost of additional model dependence in the dark partner decay modes. We also derive the irreducible constraints on models with single-component dark matter from cosmic ray searches and astrophysical observations. We find that for semi-annihilation to electrons and light quarks, the thermal relic cross sections can be excluded for dark matter masses up

   hep-phJHEP(2017)·11 citations
10. 10*

    Spatial structure of the modified Coulomb potential in a superstrong magnetic field

    S.I. Glazyrin🇷🇺 · S.I. Godunov🇷🇺

    The modification of the Coulomb potential due to the enhancement of loop corrections in a superstrong magnetic field is studied numerically. We calculate the modified potential with high precision and obtain the pattern of equipotential lines. The results confirm the general features known from previous studies, however we emphasize some differences in potential structure that can be important for problems with spatially distributed charges.

    hep-phnucl-thJETP Lett.(2017)·1 citation
11. 11*

    Hadron tomography studies by generalized parton distributions and distribution amplitudes

    S. Kumano🇯🇵

    We discuss hadron-tomography studies for the nucleon and exotic hadrons by high-energy hadron reactions. First, the constituent-counting rule is explained for determining internal quark configurations of exotic-hadron candidates by scaling properties of high-energy exclusive cross sections. Next, possibilities are discussed for investigating the generalized parton distributions (GPDs) of the nucleon and exotic hadrons at J-PARC. In particular, we study hadronic $2\to 3$ process $p+p\to N+\pi +B$, exclusive Drell-Yan process, and exotic-hadron GPDs. For determining three-dimensional structure of unstable exotic hadrons, we consider $s$-$t$ crossed quantities of the GPDs called generalized distribution amplitudes (GDAs), which can be investigated at KEKB. We explain possible studies of the GDAs by two-photon processes.

    hep-phhep-exhep-latnucl-ex+1EPJ Web Conf.(2017)·1 citation
12. 12*

    Probing the scotogenic FIMP at the LHC

    Andre Hessler🇩🇪 · Alejandro Ibarra🇩🇪 · Emiliano Molinaro🇩🇰 · Stefan Vogl🇩🇪

    We analyse the signatures at the Large Hadron Collider (LHC) of the scotogenic model, when the lightest Z2-odd particle is a singlet fermion and a feebly interacting massive particle (FIMP). We further assume that the singlet fermion constitutes the dark matter and that it is produced in the early Universe via the freeze-in mechanism. The small couplings required to reproduce the observed dark matter abundance translate into decay-lengths for the next-to-lightest Z2-odd particle which can be macroscopic, potentially leading to spectacular signatures at the LHC. We characterize the possible signals of the model according to the spectrum of the Z2-odd particles and we derive, for each of the cases, bounds on the parameters of the model from current searches.

    hep-phJHEP(2017)·87 citations
13. 13*

    In-medium pseudoscalar $D/B$ mesons and charmonium decay width

    Rahul Chhabra🇮🇳 · Arvind Kumar🇮🇳

    Using QCD sum rules and chiral SU(3) model, we investigate the effect of temperature, density, strangeness fraction and isospin asymmetric parameter on the shift in masses and decay constants of the pseudoscalar $D$ and $B$ meson in hadronic medium, which consist of nucleons and hyperons. The in-medium properties of $D$ and $B$ mesons within QCD sum rule approach depend upon the quark and gluon condensates. In chiral SU(3) model, quark and gluon condensates are introduced through the explicit symmetry breaking term and the trace anomaly property of the QCD, respectively and are written in terms of scalar fields $\sigma$, $\zeta$, $\delta$ and $\chi$. Hence, through medium modification of $\sigma$, $\zeta$, $\delta$ and $\chi$ fields, we obtain the medium modified masses and decay constants of $D$ and $B$ mesons. As an application, using ${}^3{P}_0$ model, we calculate the in-medium decay width of the higher charmonium states $\psi (3686)$, $\psi (3770)$ and $\chi (3556)$ to the $D\bar{D}$ pairs, considering the in-medium mass of $D$ mesons. These results may be important to understand the possible outcomes of high energy physics experiments, e.g., CBM and PANDA at GSI, Germany.

    hep-phnucl-thEPJA(2017)·37 citations
14. 14*

    Type-II Seesaw Model and Multilepton Signatures at Hadron Colliders

    Manimala Mitra🇮🇳 · Saurabh Niyogi🇮🇳 · Michael Spannowsky🇬🇧

    We investigate multilepton signatures, arising from the decays of doubly charged and singly charged Higgs bosons in the Type-II Seesaw model. Depending on the vacuum expectation value of the triplet $v_{\Delta }$, the doubly and singly charged Higgs bosons can decay into a large variety of multi-lepton final states. We explore all possible decay modes corresponding to different regimes of $v_{\Delta }$, that generate distinguishing four and five leptonic signatures. We focus on the 13 TeV Large Hadron Collider (LHC) and further extend the study to a very high energy proton-proton collider (VLHC) with a center-of-mass energy of 100 TeV. We find that a doubly charged Higgs boson of masses around 375 GeV can be discovered at immediate LHC runs. A heavier mass of 630 GeV can instead be discovered at the high-luminosity run of the LHC or at the VLHC with 30 ${\mathrm{fb}}^{-1}$.

    hep-phPRD(2017)·61 citations
15. 15*

    Search for short strings in~$e^{+}{e}^{-}$-annihilation

    Marina Kozhevnikova🇷🇺 · Armen Oganesian🇷🇺 · Oleg Teryaev🇷🇺

    In this work the behavior of power corrections to Adler finction in operator product expansion (OPE) is studied, in particular the possible contribution of operator of dimension 2. The OPE terms of dimension 4 and 6 are taken into account. Various experimental data on reactions of $e^{+}{e}^{-}$-annihilation to pion channels (${\pi }^{+}{\pi }^{-}$, $2{\pi }^{+}2{\pi }^{-}$, ${\pi }^{+}{\pi }^{-}2{\pi }^0$, $3{\pi }^{+}3{\pi }^{-}$, $2{\pi }^{+}2{\pi }^{-}2{\pi }^0$) are used. The high-precision fits of the experimental data are obtained and used. The method based on Borel transform of Adler function is applied. It is shown that the contribution of operator of dimension 2 is negative being compatible to zero at three standard deviations level. The strong (anti)corellation between short string and local gluon condensate is found.

    hep-phEPJ Web Conf.(2017)·1 citation
16. 16*

    Measuring Global Monopole Velocities, one by one

    Asier Lopez-Eiguren🇪🇸 · Jon Urrestilla🇪🇸 · Ana Achúcarro🇪🇸

    We present an estimation of the average velocity of a network of global monopoles in a cosmological setting using large numerical simulations. In order to obtain the value of the velocity, we improve some already known methods, and present a new one. This new method estimates individual global monopole velocities in a network, by means of detecting each monopole position in the lattice and following the path described by each one of them. Using our new estimate we can settle an open question previously posed in the literature: velocity-dependent one-scale (VOS) models for global monopoles predict two branches of scaling solutions, one with monopoles moving at subluminal speeds and one with monopoles moving at luminal speeds. Previous attempts to estimate monopole velocities had large uncertainties and were not able to settle that question. Our simulations find no evidence of a luminal branch. We also estimate the values of the parameters of the VOS model. With our new method we can also study the microphysics of the complicated dynamics of individual monopoles. Finally we use our large simulation volume to compare the results from the different estimator methods, as well as to asses the validity of the numerical approximations made.

    hep-phastro-ph.COhep-thJCAP(2017)·17 citations
17. 17*

    Investigating convergence of the reaction $\gamma p\to {\pi }^{\pm }\Delta$ and tensor meson $a_2$ exchange at high energy

    Byung-Geel Yu🇰🇷 · Kook-Jin Kong🇰🇷

    A Regge approach to the reaction processes $\gamma p\to {\pi }^{-}{\Delta }^{++}$ and $\gamma p\to {\pi }^{+}{\Delta }^0$ is presented for the description of existing data up to $E_{\gamma }=16$ GeV. The model consists of the $t$-channel $\pi (139)+\rho (775)+a_2(1320)$ exchanges which are reggeized from the relevant Born amplitude. Discussion is given on the minimal gauge prescription for the $\pi$ exchange to render convergent the divergence of the $u$-channel $\Delta$-pole in the former process. A new Lagrangian is constructed for the $a_{2}N\Delta$ coupling in this work and applied to the process for the first time with the coupling constant deduced from the duality plus vector dominance. It is shown that, while the $\pi$ exchange dominates over the process, the role of the $a_2$ exchange is crucial rather than the $\rho$ in reproducing the cross sections for total, differential, and photon polarization asymmetry to agree with data at high energy.

    hep-phnucl-thPLB(2017)·14 citations
18. 18*

    Loophole in $K\to \pi \nu \bar{\nu }$ Search \ \& $K_L\to {\pi }^0\nu \bar{\nu }$ Beyond Grossman--Nir Bound

    George W.S. Hou🇹🇼

    The Grossman-Nir bound concept is robust, but the common perception of $K_L\to {\pi }^0\nu \bar{\nu }<1.4\times 10^{-9}$ may be circumvented. Because of the blinding $K\pi 2$(3) decay, $K^{+}$ decay experiments such as E787/E949 and the currently running NA62 kinematically exclude the "blinding zone". This offers an opportunity for the currently running KOTO experiment. With no kinematic control, if the KOTO experiment is able to veto all true background, it may discover $K_L\to {\pi }^0+X^0$, where $X^0$ is an invisible "dark" boson with mass $m_{X^0}\sim m_{{\pi }^0}$. This could happen with 2015 data at hand, which supposedly should allow KOTO to reach nominal GN bound sensitivity. An explicit model of gauged $L_{\mu }-L_{\tau }$, linked with muon $g-2$ hence with very light $Z^{\prime }$, is given. Adding vector-like quarks that mix with usual quarks, $W$-boson loops induce $s\to d{Z}^{\prime }$ and $b\to s{Z}^{\prime }$ transitions. Besides realizing the scenario, the model provides further illustration of potential impact. Given that usual dark bosons linked with the photon are tightly constrained, KOTO has a unique opportunity to probe the muon-related dark sector.

    hep-phJ.Phys.Conf.Ser.(2017)·7 citations
19. 19*

    Evading Direct Dark Matter Detection in Higgs Portal Models

    Giorgio Arcadi🇩🇪 · Christian Gross🇫🇮 · Oleg Lebedev🇫🇮 · Stefan Pokorski🇵🇱 · Takashi Toma🇩🇪

    Many models of Higgs portal Dark Matter (DM) find themselves under pressure from increasingly tight direct detection constraints. In the framework of gauge field DM, we study how such bounds can be relaxed while retaining the thermal WIMP paradigm. When the hidden sector gauge symmetry is broken via the Higgs mechanism, the hidden sector generally contains unstable states which are lighter than dark matter. These states provide DM with an efficient annihilation channel. As a result, the DM relic abundance and the direct detection limits are controlled by different parameters, and the two can easily be reconciled. This simple setup realizes the idea of `secluded' dark matter naturally.

    hep-phPLB(2017)·39 citations
20. 20*

    Multi-Dimensional Phase Space Methods for Mass Measurements and Decay Topology Determination

    Baris Altunkaynak🇺🇸 · Can Kilic🇺🇸 · Matthew D. Klimek🇺🇸

    Collider events with multi-stage cascade decays fill out the kinematically allowed region in phase space with a density that is enhanced at the boundary. The boundary encodes all available information about the spectrum and is well populated even with moderate signal statistics due to this enhancement. In previous work, the improvement in the precision of mass measurements for cascade decays with three visible and one invisible particles was demonstrated when the full boundary information is used instead of endpoints of one-dimensional projections. We extend these results to cascade decays with four visible and one invisible particles. We also comment on how the topology of the cascade decay can be determined from the differential distribution of events in these scenarios.

    hep-phEPJC(2017)·10 citations
21. 21*

    Minimal left-right symmetric intersecting D-brane model

    Luis A. Anchordoqui🇺🇸 · Ignatios Antoniadis🇫🇷 · Haim Goldberg🇺🇸 · Xing Huang🇨🇳 · Dieter Lust🇩🇪 · Tomasz R. Taylor🇺🇸

    We investigate left-right symmetric extensions of the standard model based on open strings ending on D-branes, with gauge bosons due to strings attached to stacks of D-branes and chiral matter due to strings stretching between intersecting D-branes. The left-handed and right-handed fermions transform as doublets under Sp(1)_L and Sp(1)_R, and so their masses must be generated by the introduction of Higgs fields in a bi-fundamental (2,2) representation under the two Sp(1) gauge groups. For such D-brane configurations the left-right symmetry must be broken by Higgs fields in the doublet representation of Sp(1)_R and therefore Majorana mass terms are suppressed by some higher physics scale. The left-handed and right-handed neutrinos pair up to form Dirac fermions which control the decay widths of the right-handed W' boson to yield comparable branching fractions into dilepton and dijets channels. Using the most recent searches at LHC13 Run II with 2016 data we constrain the (g_R, m_{W'}) parameter space. Our analysis indicates that independent of the coupling strength g_R, gauge bosons with masses m_{W'} \agt 3.5~{\rm TeV} are not ruled out. As the LHC is just beginning to probe the TeV-scale, significant room for W' discovery remains.

    hep-phPRD(2017)·1 citation
22. 22*

    Linearized Holographic Isotropization at Finite Coupling

    Mahdi Atashi🇮🇷 · Kazem Bitaghsir Fadafan🇮🇷 · Ghadir Jafari🇮🇷

    We study holographic isotropization of an anisotropic homogeneous non-Abelian strongly coupled plasma in the presence of Gauss-Bonnet corrections. It was verified before that one can linearize Einstein's equations around the final black hole background and simplify the complicated setup. Using this approach, we study the expectation value of the boundary stress tensor. Although we consider small values of the Gauss-Bonnet coupling constant, it is found that finite coupling leads to significant increasing of the thermalization time. By including higher order corrections in linearization, we extend the results to study the effect of the Gauss-Bonnet coupling on the entropy production on the event horizon.

    ↳ hep-thgr-qchep-phEPJC(2017)·13 citations
23. 23*

    Hints against the cold and collisionless nature of dark matter from the galaxy velocity function

    Aurel Schneider🇨🇭 · Sebastian Trujillo-Gomez🇨🇭 · Emmanouil Papastergis🇳🇱 · Darren S. Reed🇨🇭 · George Lake🇨🇭

    The observed number of dwarf galaxies as a function of rotation velocity is significantly smaller than predicted by the standard model of cosmology. This discrepancy cannot be simply solved by assuming strong baryonic feedback processes, since they would violate the observed relation between maximum circular velocity ($v_{\max }$) and baryon mass of galaxies. A speculative but tantalising possibility is that the mismatch between observation and theory points towards the existence of non-cold or non-collisionless dark matter (DM). In this paper, we investigate the effects of warm, mixed (i.e warm plus cold), and self-interacting DM scenarios on the abundance of dwarf galaxies and the relation between observed HI line-width and maximum circular velocity. Both effects have the potential to alleviate the apparent mismatch between the observed and theoretical abundance of galaxies as a function of $v_{\max }$. For the case of warm and mixed DM, we show that the discrepancy disappears, even for luke-warm models that evade stringent bounds from the Lyman-$\alpha$ forest. Self-interacting DM scenarios can also provide a solution as long as they lead to extended ($\gtrsim 1.5$ kpc) dark matter cores in the density profiles of dwarf galaxies. Only models with velocity-dependent cross sections can yield such cores without violating other observational constraints at larger scales.

    ↳ astro-ph.COhep-phMNRAS(2017)·56 citations
24. 24*

    Aharonov-Bohm protection of black hole's baryon/skyrmion hair

    Gia Dvali🇩🇪 · Alexander Gußmann🇩🇪

    The baryon/skyrmion correspondence implies that the baryon number is encoded into a topological surface integral. Under certain conditions that we clarify, this surface integral can be measured by an asymptotic observer in form of an Aharonov-Bohm phase-shift in an experiment in which the skyrmion passes through a loop of a probe string. In such a setup the baryon/skyrmion number must be respected by black holes, despite the fact that it produces no long-range classical field. If initially swallowed by a black hole, the baryon number must resurface in form of a classical skyrmion hair, after the black hole evaporates below a certain critical size. Needless to say, the respect of the baryon number by black holes is expected to have potentially-interesting astrophysical consequences.

    ↳ hep-thastro-ph.HEgr-qchep-phPLB(2017)·13 citations
25. 25*

    Degravitation of the Cosmological Constant in Bigravity

    Moritz Platscher🇩🇪 · Juri Smirnov🇩🇪

    In this article the phenomenon of degravitation of the cosmological constant is studied in the framework of bigravity. It is demonstrated that despite a sizable value of the cosmological constant its gravitational effect can be only mild. The bigravity framework is chosen for this demonstration as it leads to a consistent, ghost-free theory of massive gravity. We show that degravitation takes place in the limit where the physical graviton is dominantly a gauge invariant metric combination. We present and discuss several phenomenological consequences expected in this regime.

    ↳ gr-qchep-phJCAP(2017)·13 citations
26. 26*

    Dark matter annihilation and jet quenching phenomena in the early universe

    Igor N. Mishustin🇩🇪

    Dark-matter particles like neutralinos should decouple from the hot cosmic plasma at temperatures of about 40 GeV. Later they can annihilate each other into standard-model particles, which are injected into the dense primordial plasma and quickly loose energy. This process is similar to jet quenching in ultrarelativistic heavy-ion collisions, actively studied in RHIC and LHC experiments. Using empirical information from heavy-ion experiments I show that the cosmological (anti)quark and gluon jets are damped very quickly until the plasma remains in the deconfined phase. The charged hadron and lepton jets are strongly damped until the recombination of electrons and protons. The consequences of energy transfer by the annihilation products to the cosmic matter are discussed.

    ↳ astro-ph.HEhep-ph0 citations
27. 27*

    ${\Lambda }_c\to \Lambda {\ell }^{+}{\nu }_{\ell }$ form factors and decay rates from lattice QCD with physical quark masses

    Stefan Meinel🇺🇸

    The first lattice QCD calculation of the form factors governing ${\Lambda }_c\to \Lambda {\ell }^{+}{\nu }_{\ell }$ decays is reported. The calculation was performed with two different lattice spacings and includes one ensemble with a pion mass of 139(2) MeV. The resulting predictions for the ${\Lambda }_c\to \Lambda e^{+}{\nu }_e$ and ${\Lambda }_c\to \Lambda {\mu }^{+}{\nu }_{\mu }$ decay rates divided by $|V_{cs}{|}^2$ are $0.2007(71)(74){\mathrm{ps}}^{-1}$ and $0.1945(69)(72){\mathrm{ps}}^{-1}$, respectively, where the two uncertainties are statistical and systematic. Taking the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cs}|$ from a global fit and the ${\Lambda }_c$ lifetime from experiments, this translates to branching fractions of $\mathcal{B}({\Lambda }_c\to \Lambda e^{+}{\nu }_e)=0.0380(19{)}_{\mathrm{LQCD}}(11{)}_{{\tau }_{{\Lambda }_c}}$ and $\mathcal{B}({\Lambda }_c\to \Lambda {\mu }^{+}{\nu }_{\mu })=0.0369(19{)}_{\mathrm{LQCD}}(11{)}_{{\tau }_{{\Lambda }_c}}$. These results are consistent with, and two times more precise than, the measurements performed recently by the BESIII Collaboration. Using instead the measured branching fractions together with the lattice calculation to determine the CKM matrix element gives $|V_{cs}|=0.949(24{)}_{\mathrm{LQCD}}(14{)}_{{\tau }_{{\Lambda }_c}}(49{)}_{\mathcal{B}}$.

    ↳ hep-lathep-exhep-phnucl-thPRL(2017)·95 citations
28. 28*

    Nucleon-Nucleon Correlations, Short-lived Excitations, and the Quarks Within

    O. Hen🇺🇸 · G. A. Miller🇺🇸 · E. Piasetzky🇮🇱 · L. B. Weinstein🇺🇸

    This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon. We focus on the interpretation of measurements of the EMC effect for valence quarks, a reduction in the Deep Inelastic Scattering (DIS) cross-section ratios for nuclei relative to deuterium, and its possible connection to nucleon-nucleon Short-Range Correlations (SRC) in nuclei. Our review and new analysis (involving the amplitudes of non-nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and the effects of SRC that is not an accident. The influence of strongly correlated neutron-proton pairs involving highly virtual nucleons is responsible for both effects. These correlated pairs are temporary high-density fluctuations in the nucleus in which the internal structure of the nucleons is briefly modified. This conclusion needs to be solidified by the future experiments and improved theoretical analyses that are discussed herein.

    ↳ nucl-exhep-phnucl-thRMP(2017)·431 citations
29. 29*

    Large-Scale Galaxy Bias

    Vincent Desjacques🇮🇱 · Donghui Jeong🇺🇸 · Fabian Schmidt🇩🇪

    This review presents a comprehensive overview of galaxy bias, that is, the statistical relation between the distribution of galaxies and matter. We focus on large scales where cosmic density fields are quasi-linear. On these scales, the clustering of galaxies can be described by a perturbative bias expansion, and the complicated physics of galaxy formation is absorbed by a finite set of coefficients of the expansion, called bias parameters. The review begins with a detailed derivation of this very important result, which forms the basis of the rigorous perturbative description of galaxy clustering, under the assumptions of General Relativity and Gaussian, adiabatic initial conditions. Key components of the bias expansion are all leading local gravitational observables, which include the matter density but also tidal fields and their time derivatives. We hence expand the definition of local bias to encompass all these contributions. This derivation is followed by a presentation of the peak-background split in its general form, which elucidates the physical meaning of the bias parameters, and a detailed description of the connection between bias parameters and galaxy statistics. We then review the excursion-set formalism and peak theory which provide predictions for the values of the bias parameters. In the remainder of the review, we consider the generalizations of galaxy bias required in the presence of various types of cosmological physics that go beyond pressureless matter with adiabatic, Gaussian initial conditions: primordial non-Gaussianity, massive neutrinos, baryon-CDM isocurvature perturbations, dark energy, and modified gravity. Finally, we discuss how the description of galaxy bias in the galaxies' rest frame is related to clustering statistics measured from the observed angular positions and redshifts in actual galaxy catalogs.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phPhys.Rept.(2018)·1083 citations
30. 30*

    Intrinsic limits on resolutions in muon- and electron-neutrino charged-current events in the KM3NeT/ORCA detector

    S. Adrián-Martínez🇪🇸 · M. Ageron🇫🇷 · S. Aiello🇮🇹 · A. Albert🇫🇷 · F. Ameli🇮🇹 · E. G. Anassontzis🇺🇸 · M. Andre🇪🇸 · G. Androulakis🇬🇷 · M. Anghinolfi🇮🇹 · G. Anton🇩🇪 · M. Ardid🇪🇸 · T. Avgitas🇫🇷 and 241 other authors

    Studying atmospheric neutrino oscillations in the few-GeV range with a multimegaton detector promises to determine the neutrino mass hierarchy. This is the main science goal pursued by the future KM3NeT/ORCA water Cherenkov detector in the Mediterranean Sea. In this paper, the processes that limit the obtainable resolution in both energy and direction in charged-current neutrino events in the ORCA detector are investigated. These processes include the composition of the hadronic fragmentation products, the subsequent particle propagation and the photon-sampling fraction of the detector. GEANT simulations of neutrino interactions in seawater produced by GENIE are used to study the effects in the 1 - 20 GeV range. It is found that fluctuations in the hadronic cascade in conjunction with the variation of the inelasticity y are most detrimental to the resolutions. The effect of limited photon sampling in the detector is of significantly less importance. These results will therefore also be applicable to similar detectors/media, such as those in ice.

    ↳ physics.ins-dethep-exhep-phJHEP(2017)·44 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.