Thu·Jul 12, 2018Thursday·July 12, 2018

1. 01*

   Displaced Vertices from Hidden Glue

   Gustavo Burdman🇧🇷 · Gabriela Lichtenstein🇧🇷

   We consider the phenomenology of glueball production and decay in theories with hidden glue. We focus on the case of folded supersymmetry (FSUSY) , where there is an unbroken $SU(3)$ gauge theory in the absence of light matter, leading to the formation of glueballs. We study their production through the annihilation of folded squarks into hidden gluons at the LHC, and model their fragmentation into glueballs. We obtain the distribution of displaced vertices, which is directly determined by the folded squark mass scale. Although here we specifically apply it to FSUSY, the procedure to model the hidden glue fragmentation into glueballs can be generalized to other similar theories.

   hep-phhep-exJHEP(2018)·21 citations
2. 02*

   Search for Excited $u$ and $d$ Quarks in Dijet Final States at Future $pp$ Colliders

   Ahmet Nuri Akay (TOBB ETU)🇹🇷 · Yusuf Oguzhan Günaydin (Kahrmanmaras Sutcu Imam University)🇹🇷 · Mehmet Sahin (Usak University)🇹🇷 · Saleh Sultansoy (TOBB ETU)🇹🇷

   Resonant production of excited $u$ and $d$ quarks at the Future Circular Collider and Super proton-proton Collider have been researched. Dominant jet-jet decay mode has been considered. It is shown that FCC and SppC have great potential for discovery of excited $u$ ($d$) quark: up to 44.1 (36.3) and 58.4 (47.8) TeV masses, respectively. For degenerate case (M${}_{u^{\star }}$ = M${}_{d^{\star }}$), these values are 45.9 and 60.9 TeV, respectively. This discovery will also afford an opportunity to determine the compositeness scale up to multi-PeV level.

   hep-phAdv.High Energy Phys.(2019)·3 citations
3. 03*

   Constraining unintegrated gluon distributions from inclusive photon production in proton-proton collisions at the LHC

   Sanjin Benić🇯🇵 · Kenji Fukushima🇯🇵 · Oscar Garcia-Montero🇩🇪 · Raju Venugopalan🇺🇸

   We compute the leading order (LO) $qg\to q\gamma$ and next-to-leading order (NLO) $gg\to q\bar{q}\gamma$ contributions to inclusive photon production in proton-proton (p+p) collisions at the LHC. These channels provide the dominant contribution at LO and NLO for photon transverse momenta $k_{\gamma \perp }$ corresponding to momentum fractions of $x\le 0.01$ in the colliding protons. Our computations, performed in the dilute-dense framework of the Color Glass Condensate effective field theory (CGC EFT), show that the NLO contribution dominates at small-$x$ because it is sensitive to $k_{\perp }$-dependent unintegrated gluon distributions in both of the protons. We predict a maximal $10\%$ modification of the cross section at low $k_{\gamma \perp }$ as a direct consequence of the violation of $k_{\perp }$-factorization. The coherence effects responsible for this modification are enhanced in nuclei and can be identified from inclusive photon measurements in proton-nucleus collisions. We provide numerical results for the isolated inclusive photon cross section for $k_{\gamma \perp }\le 20$ GeV in p+p collisions that can be tested in the future at the LHC.

   hep-phnucl-exnucl-thPLB(2019)·44 citations
4. 04*

   Interplay of the LHC and non-LHC Dark Matter searches in the Effective Field Theory approach

   Alexander Belyaev🇬🇧 · Enrico Bertuzzo🇧🇷 · Cristian Caniu Barros🇧🇷 · Oscar Eboli🇧🇷 · Giovanni Grilli di Cortona🇧🇷 · Fabio Iocco🇧🇷 · Alexander Pukhov🇷🇺

   We present accurate and up-to-date constraints on the complete set of dimension five and six operators with scalar, fermion and vector Dark Matter (DM). We find limits using LHC mono-jet data, spin inde- pendent and spin dependent direct searches, relic density and CMB, and show the interplay between high and low energy data in setting bounds on the parameter space. In order to properly compare data taken at different energies, we take into account the effect of the running and mixing of operators. We also take into account the local density uncertainties affecting direct detection data, and apply EFT validity criteria related to the cut on the invariant mass of DM pair production at the LHC, which turns out to be especially important for the case of vector DM. Finally, we estimate the potential of the future LHC runs to probe DM parameter space.

   hep-phPRD(2019)·58 citations
5. 05*

   s-channel Single Top Quark Production and Decay at NNLO in QCD

   Ze Long Liu🇩🇪 · Jun Gao🇨🇳

   We report on a fully differential next-to-next-to-leading order (NNLO) calculation of s-channel single top (anti-)quark production with a semi-leptonic decay at the LHC, neglecting the color correlation between the light and heavy quark lines and in the narrow width approximation. The NNLO corrections can increase the cross section by about 10% in the low transverse momentum region of the top quark and reduce scale variation uncertainty. In order to compare with experimental results without unfolding procedures, we also present theoretical predictions with fiducial cuts, including total cross sections and distributions of observables used in the experimental multivariate analysis. The NNLO corrections are found to be about -8% for fiducial cross sections.

   hep-phhep-exPRD(2018)·40 citations
6. 06*

   High-Precision Electroweak SUSY Production Cross Sections at e+e- Colliders

   S. Heinemeyer🇪🇸 · C. Schappacher🇪🇸

   For the search for electroweak (EW) particles in the Minimal Supersymmetric Standard Model (MSSM) as well as for future precision analyses of these particles an accurate knowledge of their production and decay properties is mandatory. We evaluate the cross sections for the chargino, neutralino and slepton production at e+e- colliders in the MSSM with complex parameters (cMSSM). The evaluation is based on a full one-loop calculation of all possible production channels including soft and hard photon radiation. The dependence of the cross sections on the relevant cMSSM parameters is analyzed numerically. We find sizable contributions to many production cross sections. They amount to roughly 15% of the tree-level results but can go up to 40% or higher in extreme cases. Also the dependence on complex parameters of the one-loop corrections for many production channels was found non-negligible. The full one-loop contributions are thus crucial for physics analyses at a future linear e+e- collider such as the ILC or CLIC.

   hep-phPoS(2018)·1 citation
7. 07*

   New physics effects in purely leptonic $B_s^{\ast }$ decays

   Suman Kumbhakar🇮🇳 · Jyoti Saini🇮🇳

   Recently several measurements in the neutral current sector $b\to s{l}^{+}{l}^{-}$ ($l=e$ or $\mu$) as well as in the charged current sector $b\to c\tau \bar{\nu }$ show significant deviations from their Standard Model predictions. It has been shown that two different new physics solutions can explain all the anomalies in $b\to s{l}^{+}{l}^{-}$ sector. Both these solutions are in the form of linear combinations of the two operators $(\bar{s}{\gamma }^{\alpha }{P}_{L}b)(\bar{\mu }{\gamma }_{\alpha }\mu )$ and $(\bar{s}{\gamma }^{\alpha }{P}_{L}b)(\bar{\mu }{\gamma }_{\alpha }{\gamma }_5\mu )$. We show that the longitudinal polarization asymmetry of the muons in $B_s^{\ast }\to {\mu }^{+}{\mu }^{-}$ decay is a good discriminant between the two solutions if it can be measured to a precision of $10\%$, provided the new physics Wilson coefficients are real. If they are complex, the theoretical uncertainties in this asymmetry are too large to provide effective discrimination. We also investigate the potential impact of $b\to c\tau \bar{\nu }$ anomalies on $b\to s{\tau }^{+}{\tau }^{-}$ transitions. We consider a model where the new phyics contributions to these two transitions are strongly correlated. We find that the branching ratio of $B_s^{\ast }\to {\tau }^{+}{\tau }^{-}$ can be enhanced by three orders of magnitude.

   hep-phEPJC(2019)·19 citations
8. 08*

   Simplified Bethe-Salpeter Description of Basic Pseudoscalar-Meson Features

   Wolfgang Lucha🇦🇹

   We assess a description of pseudoscalar mesons as pseudo-Goldstone bosons by its compatibility with some Gell-Mann-Oakes-Renner-type relation.

   hep-phnucl-thEPJ Web Conf.(2018)·0 citations
9. 09*

   Energy and system size dependence of subnucleonic fluctuations

   Heikki Mäntysaari🇫🇮 · Björn Schenke🇺🇸

   The energy evolution of the fluctuating proton structure is studied by solving the JIMWLK renormalization group equation. The initial condition at moderate $x$ is obtained by fitting the charm reduced cross section data from HERA, requiring that the proton size remains compatible with the diffractive vector meson production measurements. Additionally, we show that the nucleon shape fluctuations are visible in exclusive vector meson production off nuclei.

   hep-phnucl-thNPA(2019)·0 citations
10. 10*

    X(3872) and Its Heavy Quark Spin Symmetry Partners in QCD Sum Rules

    Halil Mutuk🇹🇷 · Yasemin Sarac🇹🇷 · Hasan Gumus🇹🇷 · Altug Ozpineci🇹🇷

    X(3872) presents many surprises after its discovery more than ten years ago. Understanding its properties is crucial to understand the spectrum of possible exotic mesons. In this work, X(3872) meson and its heavy quark spin symmetry (HQSS) partners (including the mesons in the bottom sector) are studied within the QCD Sum Rules approach using a current motivated by the molecular picture of X(3872). We predict four heavy partners to X(3872) and bottomonium with the masses and J^PC quantum numbers. Obtained results are in good agreement with the previous studies and available experimental data within errors.

    hep-phEPJC(2018)·17 citations
11. 11*

    Form factors for the rare ${\Lambda }_b({\Lambda }_b^{\ast })\text{rar}N{\ell }^{+}{\ell }^{-}$ decays in light cone QCD sum rules

    T. M. Aliev (1)🇹🇷 · T. Barakat (2)🇸🇦 · M. Savci (1) ((1) Middle East Technical University/Ankara/Turkey, (2) King Saud University/Riyadh/Saudi Arabia)

    Form factors of the rare ${\Lambda }_b({\Lambda }_b^{\ast })\to N{\ell }^{+}{\ell }^{-}$ decays are calculated in the framework of the light cone QCD sum rules by taking into account of the contributions from the negative parity baryons. Using the obtained results on the form factors, the branching ratios of the considered decays are estimated. The numerical survey for the branching ratios of the ${\Lambda }_b\text{rar}N{\ell }^{+}{\ell }^{-}$ and ${\Lambda }_b^{\ast }\text{rar}N{\ell }^{+}{\ell }^{-}$ decays indicate that these transitions could be measurable in LHCb in near future. Comparison of our predictions on the form factors and branching ratios with those existing in the literature is also performed.

    hep-phPRD(2018)·8 citations
12. 12*

    NNNLO pressure of cold quark matter: leading logarithm

    Tyler Gorda🇫🇮 · Aleksi Kurkela🇨🇭 · Paul Romatschke🇺🇸 · Saga Säppi🇫🇮 · Aleksi Vuorinen🇫🇮

    At high baryon chemical potential ${\mu }_B$, the equation of state of QCD allows a weak-coupling expansion in the QCD coupling ${\alpha }_s$. The result is currently known up to and including the full next-to-next-to-leading order (NNLO) ${\alpha }_s^2$. Starting at this order, the computations are complicated by the modification of particle propagation in a dense medium, which necessitates non-perturbative treatment of the scale ${\alpha }_s^{1/2}{\mu }_B$. In this work, we apply a Hard-Thermal-Loop scheme for capturing the contributions of this scale to the weak-coupling expansion, and use it to determine the leading-logarithm contribution to NNNLO: ${\alpha }_s^3{\ln }^2{\alpha }_s$. This result is the first improvement to the equation of state of massless cold quark matter in 40 years. The new term is negligibly small, and thus significantly increases our confidence in the applicability of the weak-coupling expansion.

    hep-phastro-ph.HEnucl-thPRL(2018)·159 citations
13. 13*

    Collider signatures for dark matter and long-lived particles with Pythia 8

    Nishita Desai🇫🇷

    We describe the implementation of four models for production of dark matter or as- sociated particles at the LHC based on the simplest extensions of the Standard Model. The first kind of models include dark matter production via s-channel mediators. This includes production in association with a jet for a vector boson (Z') or scalar (S) mediator as well as mono-higgs production via associated hZ' production. We implement the simplest t-channel mediator in the form of a scalar with leptonic quantum numbers and completely generic Yukawa couplings to the dark matter fermion and a right-handed SM lepton. Finally, we implement a generalised model of mixed dark matter where the dark matter is a mixture of an SU(2) singlet and N-plet. We find that the last two models are also ideally suited to study the production of a range of long-lived particle signatures. We illustrate this by reinterpreting the limits from CMS search for heavy charged particles for the t-channel case.

    hep-ph3 citations
14. 14*

    The three- and four-Higgs couplings in the general two-Higgs-doublet model

    D. Jurciukonis🇱🇹 · L. Lavoura🇵🇹

    We apply the unitarity bounds and the bounded-from-below (BFB) bounds to the most general scalar potential of the two-Higgs-doublet model (2HDM). We do this in the Higgs basis, i.e. in the basis for the scalar doublets where only one doublet has vacuum expectation value. In this way we obtain bounds on the scalar masses and couplings that are valid for all 2HDMs. We compare those bounds to the analogous bounds that we have obtained for other simple extensions of the Standard Model (SM), namely the 2HDM extended by one scalar singlet and the extension of the SM through two scalar singlets.

    hep-phJHEP(2018)·20 citations
15. 15*

    The Bearable Compositeness of Leptons

    Michele Frigerio🇫🇷 · Marco Nardecchia🇮🇹 · Javi Serra🇩🇪 · Luca Vecchi🇨🇭

    Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the bounds from charged lepton flavor and CP violating observables. We put forward a $U(1{)}^3\times CP$ symmetry of the composite sector, in order to allow the new physics to be not far above the TeV scale. This hypothesis effectively suppresses the new contributions to the electron EDM and $\mu \to e\gamma$, by far the most constraining observables, and results in a novel pattern of flavor violation and neutrino masses. The CP violation in the elementary-composite mixing is shown to induce a CKM phase of the correct size, as well as order-one phases in the PMNS matrix. We compare with the alternative possibility of introducing multiple scales of compositeness for leptons, that also allow to evade flavor and CP constraints. Finally, we examine violations of lepton flavor universality in $B$-meson semi-leptonic decays. The neutral-current anomalies can be accommodated, predicting strong correlations among different lepton flavors, with a few channels close to the experimental sensitivity.

    hep-phJHEP(2018)·36 citations
16. 16*

    A Thermal Neutrino Portal to Sub-MeV Dark Matter

    Asher Berlin🇺🇸 · Nikita Blinov🇺🇸

    Thermal relics lighter than an MeV contribute to the energy density of the universe at the time of nucleosynthesis and recombination. Constraints on extra radiation degrees of freedom typically exclude even the simplest of such dark sectors. We explore the possibility that a sub-MeV dark sector entered equilibrium with the Standard Model after neutrino-photon decoupling, which significantly weakens these constraints and naturally arises in the context of neutrino mass generation through the spontaneous breaking of lepton number. Acquiring an adequate dark matter abundance independently motivates the MeV-scale in these models through the coincidence of gravitational, matter-radiation equality, and neutrino mass scales, $(m_{\text{Pl}}/T^{\text{MRE}}{)}^{1/4}{m}_{\nu }\sim \text{MeV}$. This class of scenarios will be decisively tested by future measurements of the cosmic microwave background and matter structure of the universe. While the dark sector dominantly interacts with Standard Model neutrinos, large couplings to nucleons are possible in principle, leading to observable signals at proposed low-threshold direct detection experiments.

    hep-phastro-ph.COPRD(2019)·81 citations
17. 17*

    Majorana Neutrino Masses in the RGEs for Lepton Flavour Violation

    Sacha Davidson🇫🇷 · Martin Gorbahn🇬🇧 · Matthew Leak🇬🇧

    We suppose that the observed neutrino masses can be parametrised by a lepton number violating dimension-five operator, and calculate the mixing of double insertions of this operator into lepton flavour changing dimension-six operators of the standard model effective theory. This allows to predict the log-enhanced, but $m_{\nu }^2$-suppressed lepton flavour violation that is generic to high-scale Majorana neutrino mass models. We also consider the Two Higgs Doublet Model, where the second Higgs allows the construction of three additional dimension-five operators, and evaluate the corresponding anomalous dimensions. The sensitivity of current searches for lepton flavour violation to these additional Wilson coefficients is then examined.

    hep-phPRD(2018)·36 citations
18. 18*

    Signs of heavy Higgs bosons at CLIC: An $e^{+}{e}^{-}$ road to the Electroweak Phase Transition

    J. M. No🇪🇸 · M. Spannowsky🇬🇧

    We analyse the sensitivity of the proposed Compact Linear Collider (CLIC) to the existence of beyond the Standard Model (SM) Higgs bosons through their decays into pairs of massive gauge bosons $H\to VV$ and SM-like Higgses $H\to hh$, considering CLIC centre of mass energies $\sqrt{s}=1.4$ TeV and $3$ TeV. We find that resonant di-Higgs searches at CLIC would allow for up to two orders of magnitude improvement w.r.t. the sensitivity achievable by HL-LHC in the mass range $m_H\in [250\mathrm{GeV},1\mathrm{TeV}]$. Focusing then on a real singlet extension of the SM, we explore the prospects of heavy Higgs searches at CLIC for probing the regions of parameter space yielding a strongly first order electroweak phase transition that could generate the observed matter-antimatter asymmetry of the Universe. Our study illustrates the complementarity between CLIC and other possible future colliders like FCC-ee in probing singlet extensions of the SM, and shows that high-energy $e^{+}{e}^{-}$ colliders provide a powerful means to unravel the nature of electroweak symmetry breaking in the early Universe.

    hep-phEPJC(2019)·19 citations
19. 19*

    Constraints on $f(R)$ theories of gravity from GW170817

    Soumya Jana🇮🇳 · Subhendra Mohanty (PRL Ahmedabad, India)🇮🇳

    A novel constraint on $f(R)$ theories of gravity is obtained from the gravitational wave signal emitted from the binary neutron star merger event GW170817. The $f(R)$ theories possess an additional massive scalar degree of freedom apart from the massless spin-2 modes. The corresponding scalar field contributes an additional attractive, short-ranged "fifth" force affecting the gravitational wave radiation process. We realize that chameleon screening is necessary to conform with the observation. A model independent bound $|f^{\prime }(R_0)-1|<3\times 10^{-3}$ has been obtained, where the prime denotes the derivative with respect $R$ and $R_0$ is the curvature of our Universe at present. Though we use the nonrelativistic approximations and obtain an order of magnitude estimate of the bound, it comes from direct observations of gravitational waves and thus it is worth noting. This bound is stronger/equivalent compared to some earlier other bounds such as from the Cassini mission in the Solar-System, Supernova monopole radiation, the observed CMB spectrum, galaxy cluster density profile, etc., although it is weaker than best current constraints ($|f^{\prime }(R_0)-1|\lesssim 10^{-6}$) from cosmology. Using the bound obtained, we also constrain the parameter space in the $f(R)$ theories of dark energy like Hu-Sawicki, Starobinsky, and Tsujikawa models.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-phPRD(2019)·46 citations
20. 20*

    Transport phenomena with chiral fermions in strong magnetic fields

    Koichi Hattori🇨🇳

    I discuss the electrical conductivity, bulk viscosity, and heavy-quark diffusion coefficient in strong magnetic fields putting emphasis on consequences of the chirality conservation on the perturbative relaxation dynamics.

    ↳ nucl-thhep-phNPA(2019)·2 citations
21. 21*

    Measurements of isospin asymmetry and difference of direct $CP$ asymmetries in inclusive $B\to X_s\gamma$ decays

    S. Watanuki🇯🇵 · A. Ishikawa🇯🇵 · I. Adachi🇯🇵 · H. Aihara🇯🇵 · S. Al Said🇸🇦 · D. M. Asner🇺🇸 · T. Aushev🇷🇺 · R. Ayad🇸🇦 · V. Babu🇮🇳 · I. Badhrees🇸🇦 · A. M. Bakich🇦🇺 · V. Bansal🇺🇸 and 165 other authors

    We report measurements of isospin asymmetry ${\Delta }_{0-}$ and difference of direct $CP$ asymmetries $\Delta A_{CP}$ between charged and neutral $B\to X_s\gamma$ decays. This analysis is based on the data sample containing $772\times 10^{6}B\bar{B}$ pairs that was collected with the Belle detector at the KEKB energy-asymmetric $e^{+}{e}^{-}$ collider. Using a sum-of-exclusive technique with invariant $X_s$ mass up to 2.8~GeV/$c^2$, we obtain ${\Delta }_{0-}=[-0.48\pm 1.49(stat.)\pm 0.97(syst.)\pm 1.15(f_{+-}/f_{00})]$\% and $\Delta A_{CP}=[+3.69\pm 2.65(stat.)\pm 0.76(syst.)]$\%, where the last uncertainty for ${\Delta }_{0-}$ is due to the uncertainty on the production ratio of $B^{+}{B}^{-}$ to $B^0{\bar{B}}^0$ in ${\rm Y}(4S)$ decays. The measured value of ${\Delta }_{0-}$ is consistent with zero, allowing us to constrain the resolved photon contribution in the $B\to X_s\gamma$, and improve the branching fraction prediction. The result for $\Delta A_{CP}$ is consistent with the prediction of the SM. We also measure the direct $CP$ asymmetries for charged and neutral $B\to X_s\gamma$ decays. All the measurements are the most precise to date.

    ↳ hep-exhep-phPRD(2019)·43 citations
22. 22*

    Modelling the coincident observation of a high-energy neutrino and a bright blazar flare

    Shan Gao🇩🇪 · Anatoli Fedynitch🇩🇪 · Walter Winter🇩🇪 · Martin Pohl🇩🇪

    In September 2017, the IceCube Neutrino Observatory recorded a very-high-energy neutrino in directional coincidence with a blazar in an unusually bright gamma-ray state, TXS0506+056. Blazars are prominent photon sources in the universe because they harbor a relativistic jet whose radiation is strongly collimated and amplified. High-energy atomic nuclei known as cosmic rays can produce neutrinos; thus the recent detection may help identifying the sources of the diffuse neutrino flux and the energetic cosmic rays. Here we report on a self-consistent analysis of the physical relation between the observed neutrino and the blazar, in particular the time evolution and spectral behavior of neutrino and photon emission. We demonstrate that a moderate enhancement in the number of cosmic rays during the flare can yield a very strong increase of the neutrino flux which is limited by co-produced hard X-rays and TeV gamma rays. We also test typical radiation models for compatibility and identify several model classes as incompatible with the observations. We investigate to what degree the findings can be generalized to the entire population of blazars, to determine the relation between their output in photons, neutrinos, and cosmic rays, and suggest how to optimize the strategy of future observations.

    ↳ astro-ph.HEhep-phNature Astron.(2019)·296 citations
23. 23*

    Accretion of Dissipative Dark Matter onto Active Galactic Nuclei

    Nadav Joseph Outmezguine🇮🇱 · Oren Slone🇺🇸 · Walter Tangarife🇺🇸 · Lorenzo Ubaldi🇮🇹 · Tomer Volansky🇮🇱

    We examine the possibility that accretion of Dissipative Dark Matter (DDM) onto Active Galactic Nuclei (AGN) contributes to the growth rate of Super Massive Black Holes (SMBHs). Such a scenario could alleviate tension associated with anomalously large SMBHs measured at very early cosmic times, as well as observations that indicate that the growth of the most massive SMBHs occurs before $z\sim 6$, with little growth at later times. These observations are not readily explained within standard AGN theory. We find a range in the parameter space of DDM models where we both expect efficient accretion to occur and which is consistent with observations of a large sample of measured SMBHs. When DDM accretion is included, the predicted evolution of this sample seems to be more consistent with assumptions regarding maximal BH seed masses and maximal AGN luminosities.

    ↳ astro-ph.GAastro-ph.HEhep-phJHEP(2018)·14 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.