Mon·May 20, 2019Monday·May 20, 2019

1. 01*

   Twist-3 contributions to $\gamma \gamma \to {\pi }^{+}{\pi }^{-},K^{+}{K}^{-}$ processes in perturbative QCD approach

   Cong Wang🇨🇳 · Jun-Kang He🇨🇳 · Ming-Zhen Zhou🇨🇳

   As one of the simplest hadronic processes, $\gamma \gamma \to M^{+}{M}^{-}$ ($M=\pi ,K$) could be a good testing ground for our understanding of the perturbative and nonperturbative structure of QCD, and will be studied with high precision at BELLE-\RNum{2} in the near future. In this paper, we revisit these processes with twist-3 corrections in the perturbative QCD approach based on the $k_T$ factorization theorem, in which transverse degrees of freedom as well as resummation effects are taken into account. The influence of the distribution amplitudes on the cross sections are discussed in detail. Our work shows that not only the transverse momentum effects but also the twist-3 corrections play a significant role in the processes $\gamma \gamma \to M^{+}{M}^{-}$ in the intermediate energy region. Especially in the few GeV region, the twist-3 contributions become dominant in the cross sections. And it is noteworthy that both the twist-3 result of the ${\pi }^{+}{\pi }^{-}$ cross section and that of the $K^{+}{K}^{-}$ cross section agree well with the BELLE and ALEPH measurements. For the pion and kaon angular distributions, there still exist discrepancies between our results and the experimental measurements. Possible reasons for these discrepancies are discussed briefly.

   hep-phEPJC(2019)·2 citations
2. 02*

   A new combined analysis of elastic and charge exchange $KN(\bar{K}N)$ scatterings in the Regge realm

   Byung-Geel Yu🇰🇷 · Kook-Jin Kong🇰🇷

   The Regge features of elastic $K^{\pm }N\to K^{\pm }N$, and charge exchange $K^{-}p\to {\bar{K}}^{0}n$ and $K^{+}n\to K^{0}p$ reactions are described by using a combined analysis of all these channels at high momenta. Based on the meson exchanges in the $t$-channel with their decays to $K\bar{K}$ pair allowed, the exchanges of $\rho (775)+\omega (782)$ are excluded in contrast to existing model calculations and the present work follows a new scheme for the meson exchanges $a_0(980)+\varphi (1020)+f_2(1275)+a_2(1320)$ reggeized for the forward elastic scattering amplitude together with Pomeron. The charge exchange reactions are described by $a_0(980)+a_2(1320)$ exchanges in the $t$-channel. Dominance of the isoscalar $f_2$ and Pomeron exchanges beyond $P_{\mathrm{Lab}}\approx 3$ GeV/$c$ is shown in the elastic process. Both the isovector $a_0$ and $a_2$ exchanges in charge exchange reactions play the respective roles in the low and high momentum region. Differential and total cross sections are presented to compare with existing data. Discussion is given to the polarization of $K^{-}p\to K^{-}p$ at $P_{Lab}=10$ GeV/$c$ and $K^{-}p\to {\bar{K}}^{0}n$ at $P_{Lab}=$ 8 GeV/$c$.

   hep-phnucl-thPRC(2019)·2 citations
3. 03*

   Effect of color on rapidity gap survival

   Zoltan Nagy🇩🇪 · Davison E. Soper🇺🇸

   We study the probability for no jets with transverse momenta above a given cut to be found in the rapidity region between two high pT jets with a large rapidity separation. Our investigation uses the parton shower event generator DEDUCTOR with color beyond the leading-color-plus approximation included perturbatively.

   hep-phPRD(2019)·13 citations
4. 04*

   Gauge Technique approximation to the $\pi \gamma$ production and the pion transition form factor

   V. Sauli🇨🇿

   The pion transition form factor $G(q^2)$ is computed on the entire domain of spacelike and timelike momenta using a quantum field theory continuum approach. In analytical continuation of the function $G(Q^2)$ we utilized the Gauge Technique with the quark propagator determined from Minkowski space solution of QCD Dyson-Schwinger equations. The scale is set up by the phenomena of dynamical chiral symmetry breaking, which is a striking feature of low energy QCD.

   hep-phPRD(2020)·8 citations
5. 05*

   Non-Abelian Vector Boson as FIMP Dark Matter

   Basabendu Barman🇮🇳 · Subhaditya Bhattacharya🇮🇳 · Mohammadreza Zakeri🇨🇳

   In this analysis we demonstrate the freeze-in realization of a non-abelian vector boson dark matter (DM). We choose to elaborate an existing $SU(2{)}_N$ extension ($N$ stands for neutral) of the Standard Model (SM) with an additional $U(1)=S^{{}^{\prime }}$ global symmetry, which stabilizes the vector boson ($X,\bar{X}$) as DM through unbroken $S=T_{3N}+S^{{}^{\prime }}$ and as lightest odd $S$ particle. The analysis reveals that the contribution to the freeze-in production of DM from the decay of a heavier scalar bidoublet ${\zeta }_1^{0,\pm }\to {\zeta }_2^{0,\pm }X$ is important even after the freeze-out of ${\zeta }_1^{0,\pm }$ in equilibrium with thermal bath. Moreover, the neutral component of $SU(2{)}_N$ scalar triplet ($\Delta$), responsible for neutrino mass generation in this framework, turns out to serve as additional DMs in the model and offers a multipartite freeze-in DM set up to explore. The allowed parameter space is obtained after estimating constraints from CMB, BBN and AMS-02 bound. This exercise nicely complements the freeze-out realization of ($X,\bar{X}$) as weakly interacting massive particle (WIMP) and distinguishes it through stable charge track signature at collider compared to leptonic signal excess as found in WIMP scenario.

   hep-phJCAP(2020)·32 citations
6. 06*

   Axiflavon-Higgs Unification

   Tommi Alanne🇩🇪 · Simone Blasi🇩🇪 · Florian Goertz🇩🇪

   In this talk, a unified model of scalar particles that addresses the flavour hierarchies, solves the strong CP problem, delivers a dark matter candidate, and radiatively triggers electroweak symmetry breaking is discussed. The recently proposed axiflavon is embedded together with an (elementary) Goldstone Higgs-sector in a single multiplet (and thereby also a model of flavour and strong CP conservation for the latter is provided). Bounds on the axion decay constant follow from requiring a SM-like Higgs potential at low energies and are confronted with constraints from flavour physics and astrophysics. In the minimal implementation, the axion decay constant is restricted to $f_a\approx (10^{11}-10^{12})$ GeV, while adding right-handed neutrinos allows for a heavy-axion model at lower energies, down to $f_a\sim 10$ TeV.

   hep-ph3 citations
7. 07*

   Voyage Across the 2HDM Type-II with Magellan

   Elena Accomando🇬🇧 · David Englert🇬🇧 · Ciara Byers🇬🇧 · Jonathan Hays🇬🇧 · Stefano Moretti🇬🇧

   We review the status of the 2-Higgs Doublet Model (2HDM) Type-II, in the light of the current experimental results and various theoretical consistency conditions. In doing so, we adopt a new numerical framework, called Magellan, to explore the full parameter space of the model. Magellan uses a simple, Markov Chain Monte Carlo technique for the exploration and leverages the use of modern tools, allowing the user to perform inference on the model in an efficient way. The framework exploits the output of well-known Higgs production and decay programs, together with that of packages implementing the current results of both direct and indirect Higgs boson searches. We further illustrate how future measurements can be incorporated in such a framework, through the example of neutral heavy Higgs boson production and decay via the gluon-gluon fusion mode in a variety of final states.

   hep-phPRD(2022)·11 citations
8. 08*

   Z boson production in proton-lead collisions at the LHC accounting for transverse momenta of initial partons

   E. Blanco🇵🇱 · A. van Hameren🇵🇱 · H. Jung🇩🇪 · A. Kusina🇵🇱 · K. Kutak🇵🇱

   We perform a calculation of inclusive $Z$ boson production in proton-lead collisions at the LHC taking into account the transverse momenta of the initial partons. We use the framework of $k_T$-factorization combining transverse momentum dependent parton distributions (TMDs) with off-shell matrix elements. In order to do it we need to construct appropriate TMDs for lead nuclei which is done using the parton branching method. Our computations are compared with data from CMS taken at $\sqrt{s}=5.02$ TeV. The results are in good agreement with the measurements especially the transverse momentum distribution of the $Z$ boson.

   hep-phPRD(2019)·27 citations
9. 09*

   Gapped Continuum Kaluza-Klein spectrum

   Eugenio Megias🇪🇸 · Mariano Quiros🇪🇸

   We consider a warped five-dimensional model with an ultraviolet (UV) brane and, on top of the Standard Model isolated modes, continua of KK modes with different mass gaps for all particles: gauge bosons, fermions, graviton, radion and Higgs boson. The model can be considered as a modelization in five dimensions of gapped unparticles. The five dimensional metric has a singularity, at a finite (infinite) value of the proper (conformal) coordinate, which is admissible as it supports finite temperature in the form of a black hole horizon. An infrared (IR) brane, with particular jumping conditions, is introduced to trigger correct electroweak breaking. The gravitational metric is AdS${}_5$ near the UV brane, to solve the hierarchy problem with a fundamental Planck scale, and linear, in conformal coordinates, near the IR, as in the linear dilaton and five-dimensional clockwork models. The branes, and singularity, distances are fixed, à la Goldberger-Wise, by a bulk scalar field with brane potentials explicitly breaking the conformal symmetry. The bosonic continuum of KK modes with the smallest mass gap are those of gauge bosons, and so they are the most likely produced at the LHC. Mass gaps of the continuum of KK fermions do depend on their localization in the extra dimension. We have computed the spectral functions, and arbitrary Green's functions, and shown how they can modify some Standard Model processes.

   hep-phhep-thJHEP(2019)·33 citations
10. 10*

    Towards a complete next-to-logarithmic description of forward exclusive diffractive dijet electroproduction at HERA: real corrections

    R. Boussarie🇺🇸 · A. V. Grabovsky🇷🇺 · L. Szymanowski🇵🇱 · S. Wallon🇫🇷

    We studied the $ep\to ep+2jets$ diffractive cross section with ZEUS phase space. Neglecting the $t$-channel momentum in the Born and gluon dipole impact factors, we calculated the corresponding contributions to the cross section differential in $\beta =\frac{Q^2}{Q^2+M_{2jets}^2}$ and the angle $\varphi$ between the leptonic and hadronic planes. The gluon dipole contribution was obtained in the exclusive $k_t$-algorithm with the exclusive cut $y_{cut}=0.15$ in the small $y_{cut}$ approximation. In the collinear approximation we canceled singularities between real and virtual contributions to the $q\bar{q}$ dipole configuration, keeping the exact $y_{cut}$ dependency. We used the Golec-Biernat - Wüsthoff (GBW) parametrization for the dipole matrix element and linearized the double dipole contributions. The results give roughly $\frac{1}{2}$ of the observed cross section for small $\beta$ and coincides with it for large $\beta .$

    hep-phPRD(2019)·56 citations
11. 11*

    The fusion of hard and soft Pomerons: 3-jet diffractive production

    V.A. Khoze🇬🇧 · A.D. Martin🇬🇧 · M.G. Ryskin🇬🇧 · A.G. Shuvaev🇷🇺 · I.V. Surnin🇷🇺

    We consider the central exclusive production of high $E_T$ jets $pp\to p+(X+\mathrm{dijet})+p$. In particular we study the possible contamination of the purely exclusive signal by semi-exclusive production where no other secondaries are emitted in one hemisphere, between the highest $E_T$ dijet and the recoil proton, while in the other hemisphere a third jet, plus possibly additional hadron activity, is allowed, but still separated from the incoming proton by a large rapidity gap. This process arising from the fusion of a hard and a soft Pomeron has not been considered before. It turns out that it gives a negligible contribution. %contamination, which was not known before the calculation. The calculation involves a careful treatment of the QCD colour structure of the amplitudes.

    hep-phEPJC(2019)·0 citations
12. 12*

    Subleading Power Factorization with Radiative Functions

    Ian Moult🇺🇸 · Iain W. Stewart🇺🇸 · Gherardo Vita🇺🇸

    The study of amplitudes and cross sections in the soft and collinear limits allows for an understanding of their all orders behavior, and the identification of universal structures. At leading power soft emissions are eikonal, and described by Wilson lines. Beyond leading power the eikonal approximation breaks down, soft fermions must be added, and soft radiation resolves the nature of the energetic partons from which they were emitted. For both subleading power soft gluon and quark emissions, we use the soft collinear effective theory (SCET) to derive an all orders gauge invariant bare factorization, at both amplitude and cross section level. This yields universal multilocal matrix elements, which we refer to as radiative functions. These appear from subleading power Lagrangians inserted along the lightcone which dress the leading power Wilson lines. The use of SCET enables us to determine the complete set of radiative functions that appear to $\mathcal{O}({\lambda }^2)$ in the power expansion, to all orders in ${\alpha }_s$. For the particular case of event shape observables in $e^{+}{e}^{-}\to$ dijets we derive how the radiative functions contribute to the factorized cross section to $\mathcal{O}({\lambda }^2)$.

    hep-phnucl-thJHEP(2019)·91 citations
13. 13*

    Kaon Multiplicities of Semi-inclusive DIS and the Fragmentation Functions

    Chung Wen Kao🇹🇼 · Dong Jing Yang🇹🇼 · Wen Chen Chang🇹🇼

    There is an apparent discrepancy between the results of the charged kaon multiplicities off the deuteron target from HERMES and COMPASS experiments. In this article we point out that this discrepancy cannot be explained by different $Q^2$ values. Furthermore we examine the empirical parametrization of the fragmentation functions, DSS2017 carefully and find that the agreement between the theoretical estimate and the HERMES data is less satisfactory as claimed.

    hep-phhep-exnucl-exJPS Conf.Proc.(2019)·0 citations
14. 14*

    Discovery prospects of dwarf spheroidal galaxies for indirect dark matter searches

    Shin'ichiro Ando🇳🇱 · Bradley J. Kavanagh🇳🇱 · Oscar Macias🇯🇵 · Tiago Alves🇳🇱 · Siebren Broersen🇳🇱 · Stijn Delnoij🇳🇱 · Thomas Goldman🇳🇱 · Jim Groefsema🇳🇱 · Jorinde Kleverlaan🇳🇱 · Jaïr Lenssen🇳🇱 · Toon Muskens🇳🇱 · Liam X. Palma Visser🇳🇱 and 3 other authors

    We study the prospects for the Large Synoptic Survey Telescope (LSST) to find new dwarf spheroidal galaxies in the Milky Way. Adopting models of Milky-Way halo substructure and phenomenological prescriptions connecting subhalos and satellite galaxies, we obtain surface brightness distributions of $V$-band magnitude that lead us to predict that LSST will discover tens to hundreds of dwarf spheroidal galaxies above its sensitivity. The soon-to-be-discovered dwarfs will be interesting targets for indirect searches of dark matter annihilation yields. We forecast the distribution function of gamma-ray emission from dark matter annihilation in these objects, and discuss the detectability of these signals at both Fermi Large Area Telescope (LAT) and Cherenkov Telescope Array (CTA). By combining information from the predicted dwarf galaxies, we obtain an expected sensitivity to the annihilation cross section $⟨\sigma v⟩$ of $10^{-26}$ cm${}^3$ s${}^{-1}$ (for dark matter particles of mass 10 GeV with Fermi-LAT) and $5\times 10^{-24}$ cm${}^3$ s${}^{-1}$ (for dark matter particles of mass 500 GeV with CTA). We find that the current uncertainties in the mass measurement of the Milky-Way halo are relatively minor compared with the Poisson errors associated to drawing the most promising dwarfs from the underlying flux distribution.

    ↳ astro-ph.COastro-ph.HEhep-phJCAP(2019)·17 citations
15. 15*

    Transport coefficients for multi-component gas of hadrons using Chapman Enskog method

    Ashutosh Dash🇮🇳 · Subhasis Samanta🇮🇳 · Bedangadas Mohanty🇮🇳

    The transport coefficients of a multi-component hadronic gas at zero and non-zero baryon chemical potential are calculated using the Chapman-Enskog method. The calculations are done within the framework of an $S$-matrix based interacting hadron resonance gas model. In this model, the phase-shifts and cross-sections are calculated using $K$-matrix formalism and where required, by parameterizing the experimental phase-shifts. Using the energy dependence of cross-section, we find the temperature dependence of various transport coefficients such as shear viscosity, bulk viscosity, heat conductivity and diffusion coefficient. We finally compare our results regarding various transport coefficients with previous results in the literature.

    ↳ nucl-thhep-phPRD(2019)·13 citations
16. 16*

    Fast Radio Burst Cosmology and HIRAX

    Amanda Weltman🇿🇦 · Anthony Walters

    Until very recently we had as many theories to explain Fast Radio Bursts as we have observations of them. An explosion of data is coming, if not here already, and thus it is an opportune time to understand how we can use FRBs for cosmology. The HIRAX experiment, based mostly in South Africa, will be one such experiment, designed not only to observe large numbers of FRBs but also to localise them. In this short article we consider briefly, some ways in which HIRAX can change the landscape of FRB cosmology.

    ↳ astro-ph.COastro-ph.HEhep-ph7 citations
17. 17*

    CMS Higgs physics results

    Martin Flechl (on behalf of the CMS Collaboration)🇦🇹

    Recent results of searches for Higgs bosons by the CMS collaboration are presented. These consist of searches for rare Higgs boson decays, searches for additional neutral Higgs bosons, and searches for charged Higgs bosons.

    ↳ hep-exhep-ph4 citations
18. 18*

    The two-body potential of Vainshtein screened theories

    Adrien Kuntz🇫🇷

    Adding a light scalar degree of freedom to General Relativity often induces a fifth force whose magnitude is strongly constrained by laboratory experiments and solar system tests. The Vainshtein screening mechanism ensures that the effects of this supplementary force are suppressed in dense environments. However, the field solution of theories exhibiting Vainshtein screening is only known in spherically symmetric situations. In this article we examine in different configurations the two-body potential energy of pointlike particles in a specific $P(X)$ theory with Vainshtein screening. We use ideas borrowed from the Effective One-Body approach of Buonanno and Damour in order to restrict the form of the solution. Our results indicate that, even if Vainshtein screening is also fully active in the equal-mass case, the nonlinear dependance of the two-body energy on the mass ratio implies a violation of the Equivalence Principle. We compute the contribution of this effect to the Moon orbit for generic theories equipped with Vainshtein screening.

    ↳ gr-qcastro-ph.COhep-phPRD(2019)·18 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.