Tue·Jun 12, 2018Tuesday·June 12, 2018

1. 01*

   Millicharged particles in neutrino experiments

   Gabriel Magill🇨🇦 · Ryan Plestid🇨🇦 · Maxim Pospelov🇨🇦 · Yu-Dai Tsai🇺🇸

   We set constraints and future sensitivity projections on millicharged particles (MCPs) based on electron scattering data in numerous neutrino experiments, starting with MiniBooNE and the Liquid Scintillator Neutrino Detector (LSND). Both experiments are found to provide new (and leading) constraints in certain MCP mass windows: 5 - 35 MeV for LSND and 100 - 180 MeV for MiniBooNE. Furthermore, we provide projections for the ongoing Fermilab SBN program, the Deep Underground Neutrino Experiment (DUNE), and the proposed Search for Hidden Particles (SHiP) experiment. In the SBN program, SBND and MicroBooNE have the capacity to provide the leading bounds in the 100 - 300 MeV mass regime. DUNE and SHiP are capable of probing parameter space for MCP masses in the range of 5 MeV - 5 GeV that is significantly beyond the reach of existing bounds, including those from collider searches and, in the case of DUNE, the SLAC mQ experiment.

   hep-phhep-exPRL(2019)·171 citations
2. 02*

   Cornering Colored Coannihilation

   Sonia El Hedri🇩🇪 · Maikel de Vries🇩🇪

   In thermal dark matter models, allowing the dark matter candidate to coannihilate with another particle can considerably loosen the relic density constraints on the dark matter mass. In particular, introducing a single strongly interacting coannihilation partner in a dark matter model can bring the upper bound on the dark sector energy scale from a few TeV up to about 10 TeV. While these energies are outside the LHC reach, a large part of the parameter space for such coannihilating models can be explored by future hadron colliders. In this context, it is essential to determine whether the current bounds on dark matter simplified models also hold in non-minimal scenarios. In this paper, we study extended models that include multiple coannihilation partners. We show that the relic density bounds on the dark matter mass in these scenarios are stronger than for the minimal models in most of the parameter space and that weakening these bounds requires sizable interactions between the different species of coannihilation partners. Furthermore, we discuss how these new interactions as well as the additional particles in the models can lead to stronger collider bounds, notably in jets plus missing transverse energy searches. This study serves as a vital ingredient towards the determination of the highest possible energy scale for thermal dark matter models.

   hep-phJHEP(2018)·12 citations
3. 03*

   Soft-gluon corrections in top-quark production

   Nikolaos Kidonakis🇺🇸

   I review calculations of soft-gluon corrections for top-quark production in hadron collisions. I describe theoretical formalisms for their resummation and for finite-order expansions. I show that soft-gluon corrections are dominant for a large number of top-quark processes. I discuss top-antitop pair production as well as single-top production, including total cross sections and differential distributions, and compare with data from the LHC and the Tevatron. I also discuss top-quark production in association with charged Higgs bosons, $Z$ bosons, and other particles in models of new physics.

   hep-phInt.J.Mod.Phys.A(2018)·27 citations
4. 04*

   Exclusive Photoproduction $J/\psi$ in Peripheral Pb-Pb

   M. B. Gay Ducati🇧🇷 · S. Martins🇧🇷

   The exclusive photoproduction of the $J/\psi$ state is investigated in peripheral AA collisions for the energies available at the LHC, $\sqrt{s}=2.76$ TeV and $\sqrt{s}=5.02$ TeV. In order to evaluate the robustness of the light-cone color dipole formalism, previously tested in the ultraperipheral regime, the rapidity distribution and the nuclear modification factor ($R_{AA}$) were calculated for three centrality classes: 30%-50%, 50%-70% and 70%-90%. In the peripheral regime, three scenarios were considered. In the scenario 1, a similar formalism adopted in the UPC regime is used; in the scenario 2, one considers that only the spectators in the target are the ones that interact coherently with the photon; in the scenario 3, the photonuclear cross section is modified using the same geometrical constraints applyed in the scenario 2. The results obtained from the three scenarios were compared with the ALICE measurements (only $J/\psi$ at the moment), showing a better agreement in the more complete approach (scenario 3), mainly in the more central regions (30%-50% and 50%-70%) where the incertainty is smaller.

   hep-ph0 citations
5. 05*

   Realistic Tri-Bi-Maximal neutrino mixing

   Peng Chen🇨🇳 · Salvador Centelles Chuliá🇪🇸 · Gui-Jun Ding🇨🇳 · Rahul Srivastava🇪🇸 · José W. F. Valle🇪🇸

   We propose a generalized version of the Tri-Bi-Maximal (TBM) ansatz for lepton mixing, leading to non-zero reactor angle ${\theta }_{13}$ and CP violation. The latter is characterized by two CP phases. The Dirac phase affecting neutrino oscillations is nearly maximal (${\delta }_{CP}\sim \pm \pi /2$), while the Majorana phase implies narrow allowed ranges for the neutrinoless double beta decay amplitude. The solar angle ${\theta }_{12}$ lies nearly at its TBM value, while the atmospheric angle ${\theta }_{23}$ has the TBM value for maximal ${\delta }_{CP}$. Neutrino oscillation predictions can be tested in present and upcoming experiments.

   hep-phhep-exPRD(2018)·30 citations
6. 06*

   Direct CP Violation in Cabibbo-Favored Charmed Meson Decays and ${ϵ}^{\prime }/ϵ$ in $SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$ Model

   Naoyuki Haba🇯🇵 · Hiroyuki Umeeda🇯🇵 · Toshifumi Yamada🇯🇵

   Since the standard model contribution is virtually absent, any observation of direct CP violation in the Cabibbo-favored charmed meson decays would be evidence of new physics. In this paper, we conduct a quantitative study on direct CP violation in $D^0\to K^{-}{\pi }^{+}$, $D_s^{+}\to \eta {\pi }^{+}$ and $D_s^{+}\to {\eta }^{\prime }{\pi }^{+}$ decays in the $SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$ gauge extension of the standard model. In the model, direct CP violation arises mainly from the interference between the decay amplitude coming from the SM left-left current operators and that from the right-right current operators induced by $W_R^{+}$ gauge boson exchange. Interestingly, the strong phase between the two amplitudes is evaluable, since it stems from difference in QCD corrections to the left-left and right-right current operators, which is a short-distance QCD effect given by $\sim ({\alpha }_s(M_{W_L}^2)/4\pi )\log (M_{W_R}^2/M_{W_L}^2)$. We assess the maximal direct CP violation in the above decays in the $SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$ model. Additionally, we present a correlation between direct CP violation in these modes and one in $K\to \pi \pi$ decay parametrized by ${ϵ}^{\prime }$, since $W_R^{+}$ gauge boson has a sizable impact on the latter.

   hep-phJHEP(2018)·17 citations
7. 07*

   The calculation of differential and total cross sections for $W^{+}{W}^{-}\gamma$ production process in proton-proton collisions at LHC energies

   Azad I. Ahmadov🇷🇺

   The vector bosons production at the Large Hadron Collider makes it possible to investigate in detail the basic structure of electroweak interactions. Besides the LHC with a good accuracy will be measure production of weak bosons ($pp\to W^{+}{W}^{-}$). The production of weak bosons with photon ($pp\to W^{+}{W}^{-}\gamma$) provides an increasingly powerful handle at higher center-of-mass energies. We present phenomenological results for $WW\gamma$ production in proton-proton interaction at the Large Hadron Collider. In this paper, we calculate the total and differential cross sections. We consider the dependence of differential cross section distributions on transverse momentum and rapidity particles, which are produced in the final state ($W^{+}$ and $W^{-}$). We consider several important distributions, which are included in the search for new physics at the Large Hadron Collider. The results for transverse momentum distributions, rapidity distributions and total cross section are presented.

   hep-ph7 citations
8. 08*

   Same-sign top pair plus $W$ production in flavor changing vector and scalar models

   Javad Ebadi🇮🇷 · Fatemeh Elahi🇮🇷 · Morteza Khatiri🇮🇷 · Mojtaba Mohammadi Najafabadi🇮🇷

   We investigate the prospect of the LHC for discovering new physics effects via new strategies in the same-sign top pair and same-sign top pair associated with a $W$ boson signatures. Significant enhancement in production of same-sign top quarks (plus a $W$ boson) is a joint property of several models beyond the standard model. We concentrate on the leptonic (electron and muon) decay of the top quarks and study the exclusion reach of the LHC data for a simplified model approach where top quark flavor changing could occur through a $Z^{\prime }$ or a neutral scalar $\varphi$ exchange. Less background contributions and clean signature are the advantages of the leptonic decay mode of the top quarks in the same-sign production processes. A combination is performed on both same-sign top pair and same-sign top pair plus a $W$ boson production modes which enables us to reach a large fraction of the model parameter space. Assuming the couplings of new physics of the order of $10^{-2}$, the mass of a flavor changing $Z^{\prime }$ or a neutral scalar above 1 TeV could be excluded. We propose a momentum dependent charge asymmetry and angular observables in the same-sign top process which provide the possibility of separation of new physics signal from the SM backgrounds as well as discrimination of the flavor changing $tuX$ from $tcX$, where $X=Z^{\prime },\varphi$.

   hep-phPRD(2018)·10 citations
9. 09*

   On the Threshold Resummation in Forward pA Collisions

   Bo-Wen Xiao🇨🇳 · Feng Yuan🇺🇸

   In this paper, using the Higgs production in forward rapidity region in proton-nucleus collisions as an example, we demonstrate that we can construct a systematic formalism for the threshold resummation for forward rapidity particle productions in the saturation formalism. The forward threshold jet function, which satisfies the corresponding renormalization group equation, is introduced into the new factorization formula. This calculation can be easily generalized to other processes, such as single forward hadron productions at forward rapidity region, and have important phenomenological implications.

   hep-phnucl-thPLB(2019)·16 citations
10. 10*

    Searching for Charged Higgs Bosons in the $B-L$ Supersymmetric Standard Model at the High Luminosity Large Hadron Collider

    W. Abdallah🇮🇳 · A. Hammad🇨🇭 · S. Khalil🇪🇬 · S. Moretti🇬🇧

    Upon assuming the $B-L$ Supersymmetric Standard Model (BLSSM) as theoretical framework accommodating a multi-Higgs sector, we assess the scope of the High Luminosity Large Hadron Collider (HL-LHC) in accessing charged Higgs bosons ($H^{\pm }$) produced in pairs from $Z^{\prime }$ decays. We show that, by pursuing both di-jet and tau-neutrino decays, several signals can be established for $H^{\pm }$ masses ranging from about $M_W$ to above $m_t$ and $Z^{\prime }$ masses between 2.5 TeV and 3.5 TeV. The discovery can be attained, even in a background free environment in some cases, owing to the fact that the very massive resonating $Z^{\prime }$ ejects the charged Higgs bosons at very high transverse momentum, a kinematic region where any SM noise is hugely depleted.

    hep-phPLB(2019)·6 citations
11. 11*

    Study Standard Model and Majorana Neutrino Contributions to $B^{+}\to K^{(\ast )\pm }{\mu }^{+}{\mu }^{\mp }$

    Hong-lei Li🇨🇳 · Peng-cheng Lu🇨🇳 · Cong-feng Qiao🇨🇳 · Zong-guo Si🇨🇳 · Ying Wang🇨🇳

    Lepton number violation processes can be induced by the Majorana neutrino exchange, which provide evidence for the Majorana nature of neutrinos. In addition to the natural explanation of the small neutrino masses, Type-I seesaw mechanism predicts the existence of Majorana neutrinos. The aim of this work is to study the B meson rare decays $B^{+}\to K^{(\ast )+}{\mu }^{+}{\mu }^{-}$ in the standard model and its extensions, and then to investigate the same-sign decay processes $B^{+}\to K^{(\ast )-}{\mu }^{+}{\mu }^{+}$. The corresponding dilepton invariant mass distributions are predicted. It is found that the dilepton angular distributions illustrate the properties of new interactions induced by the Majorana neutrinos.

    hep-phCPC(2019)·10 citations
12. 12*

    Doubly-charged scalar in four-body decays of neutral flavored mesons

    Tianhong Wang🇨🇳 · Geng Li🇨🇳 · Yue Jiang🇨🇳 · Guo-Li Wang🇨🇳

    In this paper, we study the four-body decay processes of neutral flavored mesons, including ${\bar{K}}^0$, $D^0$, ${\bar{B}}^0$, and ${\bar{B}}_s^0$. These processes, which induced by a hypothetical doubly-charged scalar particle, violate the lepton number. The quantity $Br\times {\left(\frac{s_{\Delta }{h}_{ij}}{m_{\Delta }^2}\right)}^{-2}$ of different channels are calculated, where $s_{\Delta }$, $h_{ij}$, and $M_{\Delta }$ are parameters related to the doubly-charged scalar. For ${\bar{K}}^0\to h_1^{+}{h}_2^{+}{l}_1^{-}{l}_2^{-}$, $D^0\to h_1^{-}{h}_2^{-}{l}_1^{+}{l}_2^{+}$, and ${\bar{B}}_{d,s}^0\to h_1^{+}{h}_2^{+}{l}_1^{-}{l}_2^{-}$, it is of the order of $10^{-13}\sim 10^{-11}$ $\mathrm{Ge}{\mathrm{V}}^4$, $10^{-17}\sim 10^{-10}$ $\mathrm{Ge}{\mathrm{V}}^4$, and $10^{-17}\sim 10^{-10}$ $\mathrm{Ge}{\mathrm{V}}^4$, respectively. Based on the experimental results for the $D^0\to h_1^{-}{h}_2^{-}{l}_1^{+}{l}_2^{+}$ channels, we also set the upper limit for $\frac{s_{\Delta }{h}_{ij}}{M_{\Delta }^2}$.

    hep-phCPC(2019)·0 citations
13. 13*

    Diffractive double quarkonium production at the LHC

    C. Brenner Mariotto🇧🇷 · V. P. Goncalves🇧🇷 · R. Palota da Silva🇧🇷

    In this paper we study the inclusive and diffractive double quarkonium production. Based on the nonrelativistic QCD (NRQCD) factorization formalism for the quarkonium production mechanism we estimate the rapidity and transverse momentum dependence of the cross section for the $J/\Psi J/\Psi$ and ${\rm Y}{\rm Y}$ production in diffractive processes at LHC energies. The contributions of the color-singlet and color-octet channels are estimated and predictions for the total cross sections in the kinematical regions of the LHC experiments are also presented. Our results demonstrate that the contribution of diffractive processes is not negligible and that its study can be useful to test the Resolved Pomeron model.

    hep-ph2 citations
14. 14*

    The hadronic interaction model Sibyll-2.3c and inclusive lepton fluxes

    Anatoli Fedynitch🇩🇪 · Felix Riehn🇵🇹 · Ralph Engel🇩🇪 · Thomas K. Gaisser🇺🇸 · Todor Stanev🇺🇸

    Muons and neutrinos from cosmic ray interactions in the atmosphere originate from decays of mesons in air-showers. Sibyll-2.3c aims to give a precise description of hadronic interactions in the relevant phase space for conventional and prompt leptons in light of new accelerator data, including that from the LHC. Sibyll is designed primarily as an event generator for use in simulation of extensive air showers. Because it has been tuned for forward physics as well as the central region, it can also be used to calculate inclusive fluxes. The purpose of this paper is to describe the use of Sibyll-2.3c for calculation of fluxes of atmospheric leptons.

    hep-phastro-ph.HEPRD(2019)·217 citations
15. 15*

    Measuring CP violation in $b\to c{\tau }^{-}{\bar{\nu }}_{\tau }$ using excited charm mesons

    Daniel Aloni🇮🇱 · Yuval Grossman🇺🇸 · Abner Soffer🇮🇱

    There is growing evidence for deviation from the standard model predictions in the ratios between semi-tauonic and semi-leptonic $B$ decays, known as the $R(D^{(\ast )})$ puzzle. If the source of this non-universality is new physics, it is natural to assume that it also breaks CP symmetry. In this paper we study the possibility of measuring CP violation in semi-tauonic $B$ decays, exploiting interference between excited charm mesons. Given the current values of $R(D^{(\ast )})$, we find that our proposed CP-violation observable could be as large as about 10%. We discuss the experimental advantages of our method and propose carrying it out at Belle II and LHCb.

    hep-phhep-exPRD(2018)·12 citations
16. 16*

    Evidence of the true Higgs boson $H_T$ at the LHC Run 2

    Paolo Cea🇮🇹

    The aim of the present note is to compare the recent LHC data at $\sqrt{s}=13TeV$ with our previous theoretical proposal that the true Higgs boson $H_T$ should be a broad heavy resonance with mass around $750GeV$. We focus on the so-called golden channel $H_T\to ZZ$ where the pair of Z bosons decay leptonically to ${\ell }^{+}{\ell }^{-}{\ell }^{+}{\ell }^{-}$, $\ell$ being either an electron or a muon. We use the data collected by the ATLAS and CMS Collaborations at $\sqrt{s}=13TeV$ with an integrated luminosity of $36.1f{b}^{-1}$ and $77.4f{b}^{-1}$ respectively. We find that the experimental data from both the LHC Collaborations do display in the golden channel a rather broad resonance structure around $700GeV$ with a sizeable statistical significance. Our theoretical expectations seem to be in fair good agreement with the experimental observations. Combining the data from both the ATLAS and CMS Collaborations we obtain an evidence of the heavy Higgs boson in this channel with an estimated statistical significance of more than five standard deviations.

    hep-phhep-exMod.Phys.Lett.A(2019)·20 citations
17. 17*

    Irrational Monodromies of Vacuum Energy

    Nemanja Kaloper🇺🇸

    We present a theory with axion flux monodromies coupled to gravity, that reduces to the local vacuum energy sequester below the axion mass scales. If the axion potentials include a term generated by nonperturbative couplings to gauge sectors, with a decay constant incommensurate with monodromy periods, the low energy potential germinates a landscape of irrational axion vacua, with arbitrarily small cosmological constants. The sensitivity of the values of cosmological constants to unknown UV physics can be greatly reduced. The variation of the cosmological constant in each vacuum, from one order in perturbation theory to the next, can be much smaller than the naïve cutoff. The nonperturbative transitions in the early universe between the vacua populate this landscape, similar to the case of irrational axion. In such a landscape of vacua a small cosmological constant can naturally emerge.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2019)·14 citations
18. 18*

    Planck and Electroweak Scales Emerging from Conformal Gravity

    Ichiro Oda🇯🇵

    We show that both the Planck and electroweak mass scales can be generated from conformal gravity via the Coleman-Weinberg mechanism of dimensional transmutation. At the first step, the Planck scale is generated via the Coleman-Weinberg mechanism in the sector of conformal gravity, which means that radiative corrections associated with gravitons induce spontaneous symmetry breakdown of a local conformal symmetry. At the second step, the vacuum expectation value of a scalar field is transmitted to the sector of the standard model via a potential involving the conformally invariant part and the contribution from the Coleman-Weinberg mechanism, thereby generating the electroweak scale. The huge hierarchy between the two scales can be explained in terms of a very tiny coupling constant between the scalar and the Higgs field in a consistent way.

    ↳ hep-thgr-qchep-phEPJC(2018)·23 citations
19. 19*

    Quantum Gravity, Fakeons And Microcausality

    Damiano Anselmi🇮🇹 · Marco Piva🇮🇹

    We investigate the properties of fakeons in quantum gravity at one loop. The theory is described by a graviton multiplet, which contains the fluctuation $h_{\mu \nu }$ of the metric, a massive scalar $\varphi$ and the spin-2 fakeon ${\chi }_{\mu \nu }$. The fields $\varphi$ and ${\chi }_{\mu \nu }$ are introduced explicitly at the level of the Lagrangian by means of standard procedures. We consider two options, where $\varphi$ is quantized as a physical particle or a fakeon, and compute the absorptive part of the self-energy of the graviton multiplet. The width of ${\chi }_{\mu \nu }$, which is negative, shows that the theory predicts the violation of causality at energies larger than the fakeon mass. We address this issue and compare the results with those of the Stelle theory, where ${\chi }_{\mu \nu }$ is a ghost instead of a fakeon.

    ↳ hep-thgr-qchep-phJHEP(2018)·119 citations
20. 20*

    Equilibration in fermionic systems

    T. Bartsch🇩🇪 · G. Wolschin🇩🇪

    The time evolution of a finite fermion system towards statistical equilibrium is investigated using analytical solutions of a nonlinear partial differential equation that had been derived earlier from the Boltzmann collision term. The solutions of this fermionic diffusion equation are rederived in closed form, evaluated exactly for simplified initial conditions, and applied to hadron systems at low energies in the MeV-range, as well as to quark systems at relativistic energies in the TeV-range where antiparticle production is abundant. Conservation laws for particle number including created antiparticles, and for the energy are discussed.

    ↳ cond-mat.stat-mechhep-phAnnals Phys.(2019)·12 citations
21. 21*

    Search for a Radio Pulsar in the Remnant of Supernova 1987A

    S.-B. Zhang🇨🇳 · S. Dai🇦🇺 · G. Hobbs🇦🇺 · L. Staveley-Smith🇦🇺 · R. N. Manchester🇦🇺 · C. J. Russell🇦🇺 · G. Zanardo · X.-F. Wu🇨🇳

    We have observed the remnant of supernova SN~1987A (SNR~1987A), located in the Large Magellanic Cloud (LMC), to search for periodic and/or transient radio emission with the Parkes 64\,m-diameter radio telescope. We found no evidence of a radio pulsar in our periodicity search and derived 8$\sigma$ upper bounds on the flux density of any such source of $31\mu$Jy at 1.4~GHz and $21\mu$Jy at 3~GHz. Four candidate transient events were detected with greater than $7\sigma$ significance, with dispersion measures (DMs) in the range 150 to 840\,cm${}^{-3}$pc. For two of them, we found a second pulse at slightly lower significance. However, we cannot at present conclude that any of these are associated with a pulsar in SNR~1987A. As a check on the system, we also observed PSR~B0540$-$69, a young pulsar which also lies in the LMC. We found eight giant pulses at the DM of this pulsar. We discuss the implications of these results for models of the supernova remnant, neutron star formation and pulsar evolution.

    ↳ astro-ph.HEastro-ph.SRhep-phMNRAS(2018)·13 citations
22. 22*

    Precise predictions of charmed-bottom hadrons from lattice QCD

    Nilmani Mathur🇮🇳 · M. Padmanath🇩🇪 · Sourav Mondal🇮🇳

    We report the ground state masses of hadrons containing at least one charm and one bottom quark using lattice quantum chromodynamics. These include mesons with spin (J)-parity (P) quantum numbers J(P): 0(-), 1(-), 1(+) and 0(+) and the spin-1/2 and 3/2 baryons. Among these hadrons only the ground state of 0(-) is known experimentally and therefore our predictions provide important information for the experimental discovery of all other hadrons with these quark contents.

    ↳ hep-lathep-exhep-phPRL(2018)·163 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.