Fri·Jun 23, 2017Friday·June 23, 2017

1. 01*

   Lorentz-violating nonminimal coupling contributions in mesonic hydrogen atoms and generation of photon higher-order derivative terms

   R. Casana🇧🇷 · J. S. Rodrigues🇧🇷 · F. E. P. dos Santos🇧🇷

   We have studied the contributions of Lorentz-violating CPT-odd and CPT-even nonminimal couplings to the energy spectrum of the mesonic hydrogen and the higher-order radiative corrections to the effective action of the photon sector of a Lorentz-violating version of the scalar electrodynamics. By considering the complex scalar field describes charged mesons (pion or kaon), the non-relativistic limit of the model allows to attain upper-bounds by analyzing its contribution to the mesonic hydrogen energy. By using the experimental data for the $1S$ strong correction shift and the pure QED transitions $4P\to 3P$, the best upper-bound for the CPT-odd coupling is $<10^{-12}{\text{eV}}^{-1}$ and for the CPT-even one is $<10^{-16}{\text{eV}}^{-2}$. Besides, the CPT-odd radiative correction to the photon action is a dimension-5 operator which looks like a higher-order Carroll-Field-Jackiw term. The CPT-even radiative contribution to the photon effective action is a dimension-6 operator which would be a higher-order derivative version of the minimal CPT-even term of the standard model extension.

   hep-phhep-thPLB(2019)·5 citations
2. 02*

   Regge Trajectories of Exotic Hadrons in the Flux Tube Model

   Hemwati Nandan🇮🇳 · Akhilesh Ranjan🇮🇳

   We have investigated the Regge trajectories of exotic hadrons by considering different possible pentaquark configurations with finite quark mass in the flux tube model. Signifi- cant deviation is observed in the linear behavior of the Regge trajectories for pentaquark systems in view of the universal value of the Regge slope parameter for hadrons. The modified Regge trajectories are also compared with the available experimental and lat- tice data. It is observed that the non-linear Regge trajectories of such pentaqurk systems can be well described by the relativistic corrections in view of the current quark masses and the high rotational speed of the quarks at the end of flux tube structure.

   hep-phInt.J.Mod.Phys.A(2016)·8 citations
3. 03*

   A Model of Dark Matter, Leptogenesis, and Neutrino Mass from the $B-L$ Violation just above the Electroweak Scale

   Wei-Min Yang🇨🇳

   I suggest an extension of the SM by introducing a dark sector with the local $U(1{)}_D$ symmetry. The particles in the dark sector bring about the new physics beyond the SM. In particular the global $B-L$ symmetry is violated just above the electroweak scale, this becomes a common origin of the tiny neutrino mass, the cold dark mater and the baryon asymmetry. The model can not only account for the tiny neutrino mass and the "WIMP Miracle", but also achieve the leptogenesis around the electroweak scale. Finally, it is very possible that the model predictions are tested in near future experiments.

   hep-ph0 citations
4. 04*

   Radiative corrections to the average bremsstrahlung energy loss of high-energy muons

   Alexander Sandrock🇩🇪 · Stanislav R. Kelner🇷🇺 · Wolfgang Rhode🇩🇪

   High-energy muons can travel large thicknesses of matter. For underground neutrino and cosmic ray detectors the energy loss of muons has to be known accurately for simulations. In this article the next-to-leading order correction to the average energy loss of muons through bremsstrahlung is calculated using a modified Weizsäcker-Williams method. An analytical parametrisation of the numerical results is given.

   hep-phPLB(2018)·10 citations
5. 05*

   Transverse-momentum resummation for the signal-background interference in the $H\to \gamma \gamma$ channel at the LHC

   Leandro Cieri🇨🇭 · Francesco Coradeschi🇬🇧 · Daniel de Florian🇦🇷 · Nerina Fidanza🇦🇷

   We present an upgraded calculation of the effects of resonance-continuum interference for the Higgs boson decaying to two photons at the Large Hadron Collider, at next-to-leading order in the strong coupling ${\alpha }_S$, $O({\alpha }_S^3)$, and including transverse-momentum ($q_T$) resummation at next-to-leading logarithmic accuracy. We study the importance of the interference contribution in different transverse-momentum regions, with a particular focus on the low $q_T$ region $q_T^2<<Q^2$ (with $Q^2$ being the invariant diphoton mass) where resummation becomes essential for a reliable calculation.

   hep-phPRD(2017)·17 citations
6. 06*

   Explaining the $R_K$ and $R_{K^{\ast }}$ Anomalies With Right-handed Sneutrino

   Shaaban Khalil🇪🇬

   The recent intriguing measurements of $R_K$ and $R_{K^{\ast }}$ are important hints of new physics that violates lepton universality. We analyze the semileptonic decays $b\to s{\ell }^{+}{\ell }^{-}$ in the framework of the $B-L$ extension of Minimal Supersymmetric Standard Model (MSSM) with Inverse Seesaw (BLSSMIS). A salient feature of this model is that one of the right-handed sneutrino can be light and the neutrino Yukawa couplings are of order one. We show that the box diagram mediated by right-handed sneutrino, higgsino-like chargino, and light stop can account simultaneously for both $R_K$ and $R_{K^{\ast }}$. Therefore, while the MSSM cannot explain the $R_K$ and $R_{K^{\ast }}$ anomalies, the BLSSMIS can account for them, where a significant lepton flavor non-universality might stem from large neutrino Yukawa couplings.

   hep-phJ.Phys.G(2018)·10 citations
7. 07*

   Rare ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$ decay in the two-Higgs doublet model of type-III

   R. F. Alnahdi🇸🇦 · T. Barakat🇸🇦 · H. A. Alhendi🇸🇦

   The rare exclusive dileptonic ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$ $(\ell =\mu ,\tau )$ decays are investigated in the general two-Higgs-doublet model of type III. A significant enhancement to the branching ratios, differential branching ratios, leptons forward-backward asymmetry, and the $\Lambda$ baryon polarizations over the standard model is obtained. Measurements of these quantities will be useful for establishing the two-Higgs doublet model.

   hep-phPTEP(2017)·6 citations
8. 08*

   Regge phenomenology in ${\pi }^0$ and $\eta$ photoproduction

   V. L. Kashevarov🇩🇪 · M. Ostrick🇩🇪 · L. Tiator🇩🇪

   The $\gamma N\to {\pi }^{0}N$ and $\gamma N\to \eta N$ reactions at photon beam energies above 4 GeV are investigated within Regge models. The models include $t$-channel exchanges of vector ($\rho$ and $\omega$) and axial vector ($b_1$ and $h_1$) mesons. Moreover, Regge cuts of $\rho \mathbb{P}$, $\rho f_2$, $\omega \mathbb{P}$, and $\omega f_2$ are investigated. A good description of differential cross sections and polarization observables at photon beam energies from 4 to 15 GeV can be achieved.

   hep-phnucl-exnucl-thPRC(2017)·27 citations
9. 09*

   Novel signatures for long-lived particles at the LHC

   Shankha Banerjee🇬🇧 · Geneviève Bélanger🇫🇷 · Biplob Bhattacherjee🇮🇳 · Fawzi Boudjema🇫🇷 · Rohini M. Godbole🇮🇳 · Swagata Mukherjee🇩🇪

   In contrast to the decay products ensuing from a fast moving particle which are collimated along the original direction of the parent, those from a slow moving particle are distributed over a wide region. In the context of searches for heavy long-lived particles (LLP) at the Large Hadron Collider (LHC), we quantitatively demonstrate, using a few benchmark models, that objects which emerge from a secondary vertex due to the decay of an LLP at the TeV scale can be at large angular separations with respect to the direction of the parent LLP. A fraction of the decay products, the backward moving objects (\textit{BMO}s), can even go in the backward direction. These will give rise to striking signatures in the detectors at the LHC as these particles will traverse different layers of the detector {\it outside-in} towards the direction of the beam-pipe. Based on a simple geometrical modelling of the detector, we give examples of how this effect translates into the fraction of energy deposited in the tracker, from particles coming as far as from the hadron calorimeter, as well as those that could be entering from outside the detector into the muon chamber. The largest effect is from LLP candidates that come to rest inside the detector, such as the stopped $R$-hadrons. But the results are promising even in the case of not so heavy LLPs and/or when some of the available energy is carried by a massive invisible daughter. This urges us to look more in details at these unusual signatures, taking into account the particularities of each layer that constitutes the detector. From the \textit{BMO} perspective, we review how each layer of the detector could be exploited and what improvements can be made to enhance the shower shapes and the timing information, for instance. We also argue that the cosmic ray events, the most important background, can be easily dealt with.

   hep-phhep-exPRD(2018)·16 citations
10. 10*

    Status of the Charged Higgs Boson in Two Higgs Doublet Models

    A. Arbey🇫🇷 · F. Mahmoudi🇫🇷 · O. Stal🇸🇪 · T. Stefaniak🇺🇸

    The existence of charged Higgs boson(s) is inevitable in models with two (or more) Higgs doublets. Hence, their discovery would constitute unambiguous evidence for new physics beyond the Standard Model (SM). Taking into account all relevant results from direct charged and neutral Higgs boson searches at LEP and the LHC, as well as the most recent constraints from flavour physics, we present a detailed analysis of the current phenomenological status of the charged Higgs sector in a variety of well-motivated Two Higgs Doublet Models (2HDMs). We find that charged Higgs bosons as light as 75 GeV can still be compatible with the combined data, although this implies severely suppressed charged Higgs couplings to all fermions. In more popular models, e.g. the 2HDM of Type II, we find that flavour physics observables impose a combined lower limit on the charged Higgs mass of M_H+ > 600 GeV - independent of tan(beta) - which increases to M_H+ > 650 GeV for tan(beta) < 1. We furthermore find that in certain scenarios, the signature of a charged Higgs boson decaying into a lighter neutral Higgs boson and a W boson provides a promising experimental avenue that would greatly complement the existing LHC search programme for charged Higgs boson(s).

    hep-phhep-exEPJC(2018)·228 citations
11. 11*

    Wormholes and masses for Goldstone bosons

    Rodrigo Alonso🇨🇭 · Alfredo Urbano🇨🇭

    There exist non-trivial stationary points of the Euclidean action for an axion particle minimally coupled to Einstein gravity, dubbed wormholes. They explicitly break the continuos global shift symmetry of the axion in a non-perturbative way, and generate an effective potential that may compete with QCD depending on the value of the axion decay constant. In this paper, we explore both theoretical and phenomenological aspects of this issue. On the theory side, we address the problem of stability of the wormhole solutions, and we show that the spectrum of the quadratic action features only positive eigenvalues. On the phenomenological side, we discuss, beside the obvious application to the QCD axion, relevant consequences for models with ultralight dark matter, black hole superradiance, and the relaxation of the electroweak scale. We conclude discussing wormhole solutions for a generic coset and the potential they generate.

    hep-phastro-ph.COhep-thJHEP(2019)·114 citations
12. 12*

    More On Large-Momentum Effective Theory Approach to Parton Physics

    Xiangdong Ji🇨🇳 · Jian-Hui Zhang🇩🇪 · Yong Zhao🇺🇸

    Large-Momentum Effective Theory (or LaMET) advocated by the present authors provides a direct approach to simulate parton physics in Eulidean lattice QCD theory. Recently, there has been much interest in this theory in the literature, with some questioning its validity and effectiveness. Here we provide some discussions aiming at a further exposition of this approach. In particular, we explain why it does not have the usual power divergence problem in lattice QCD calculations for the moments of parton distributions. We show that although the Ioffe-time distribution provides an alternative way to extract the parton distribution from the same lattice observable, it also requires the same large momentum limit as in LaMET to obtain a precision calculation. With a proper quantification of errors, both extraction methods should be compared with the same lattice data.

    hep-phNPB(2017)·111 citations
13. 13*

    Polarization of prompt $J/\psi$ and ${\rm Y}$(1S) production in the color evaporation model

    Vincent Cheung🇺🇸 · Ramona Vogt🇺🇸

    We calculate the polarization of prompt $J/\psi$ and ${\rm Y}$(1S) production using the color evaporation model at leading order. We present the polarization parameter ${\lambda }_{\vartheta }$ as a function of center of mass energy and rapidity in $p+p$ collisions. We also compare the $x_F$ dependence to experimental results in $p$+Cu and $\pi$+W collisions, and predict the $x_F$ dependence in $p$+Pb collisions at fixed-target energies. At energies far above the $Q\overline{Q}$ production threshold, we find the prompt $J/\psi$ and ${\rm Y}$(1S) production to be longitudinally polarized with ${\lambda }_{\vartheta }^{J/\psi }=-0.51_{-0.16}^{+0.05}$ and ${\lambda }_{\vartheta }^{{\rm Y}(1S)}=-0.69_{-0.02}^{+0.03}$. Both prompt $J/\psi$ and prompt ${\rm Y}$(1S) are also longitudinally polarized at central rapidity, becoming transversely polarized at the most forward rapidities.

    hep-phPRD(2017)·26 citations
14. 14*

    Early kinetic decoupling of dark matter: when the standard way of calculating the thermal relic density fails

    Tobias Binder🇩🇪 · Torsten Bringmann🇳🇴 · Michael Gustafsson🇩🇪 · Andrzej Hryczuk🇳🇴

    Calculating the abundance of thermally produced dark matter particles has become a standard procedure, with sophisticated methods guaranteeing a precision that matches the percent-level accuracy in the observational determination of the dark matter density. Here, we point out that one of the main assumptions in the commonly adopted formalism, namely local thermal equilibrium during the freeze-out of annihilating dark matter particles, does not have to be satisfied in general. We present two methods for how to deal with such situations, in which the kinetic decoupling of dark matter happens so early that it interferes with the chemical decoupling process: i) an approximate treatment in terms of a coupled system of differential equations for the leading momentum moments of the dark matter distribution, and ii) a full numerical solution of the Boltzmann equation in phase-space. For illustration, we apply these methods to the case of Scalar Singlet dark matter. We explicitly show that even in this simple model the prediction for the dark matter abundance can be affected by up to one order of magnitude compared to the traditional treatment.

    ↳ astro-ph.COhep-phPRD(2017)·176 citations
15. 15*

    Physics Opportunities with the FCC-hh Injectors

    B. Goddard🇨🇭 · G. Isidori🇨🇭 · F. Teubert🇨🇭 · M. Bai🇩🇪 · A. Ball🇨🇭 · B. Batell🇺🇸 · T. Bowcock🇬🇧 · G. Cavoto🇮🇹 · A. Ceccucci🇨🇭 · M. Chrzaszcz🇨🇭 · A. Golutvin🇬🇧 · W. Herr🇨🇭 and 5 other authors

    In this chapter we explore a few examples of physics opportunities using the existing chain of accelerators at CERN, including potential upgrades. In this context the LHC ring is also considered as a part of the injector system. The objective is to find examples that constitute sensitive probes of New Physics that ideally cannot be done elsewhere or can be done significantly better at theCERN accelerator complex. Some of these physics opportunities may require a more flexible injector complex with additional functionality than that just needed to inject protons into the FCC-hh at the right energy, intensity and bunch structure. Therefore it is timely to discuss these options concurrently with the conceptual design of the FCC-hh injector system.

    ↳ physics.acc-phhep-phCERN Yellow Rep.Monogr.(2017)·8 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.