Wed·Jan 2, 2019Wednesday·January 2, 2019

1. 01*

   Finite-size dark matter and its effect on small-scale structure

   Xiaoyong Chu🇦🇹 · Camilo Garcia-Cely🇩🇪 · Hitoshi Murayama🇺🇸

   If dark matter has a finite size that is larger than its Compton wavelength, the corresponding self-interaction cross section decreases with the velocity. We investigate the implications of this Puffy Dark Matter for addressing the small-scale problems of the $\Lambda$CDM model. In particular, we show that the way the non-relativistic cross section varies with the velocity is largely independent of the dark matter internal structure when the range of the mediating force is very short. We present an explicit example in the context of a QCD-like theory of dark matter and show that low-threshold direct detection experiments have the potential to probe Puffy Dark Matter.

   hep-phPRL(2020)·40 citations
2. 02*

   Improved Bethe-Heitler formula

   Wei Zhu🇨🇳

   The bremsstrahlung cross section of electron in the atomic electric field is re-derived using the time ordered perturbative theory. The results are compared with the Bethe-Heitler formula. We indicate that both the TOPT-description and a soft version for the bremsstrahlung process predict a strong screening parameter-dependent cross section, which is missed by previous bremsstrahlung theory.

   hep-ph0 citations
3. 03*

   Top-Assisted Di-Higgs boson Production Motivated by Baryogenesis

   Wei-Shu Hou🇹🇼 · Masaya Kohda🇹🇼 · Tanmoy Modak🇹🇼

   We study top-assisted di-Higgs production via $cg\to tH\to thh$, where $h$ is the 125 GeV scalar boson, and $H$ is the $CP$-even heavy Higgs. The context is the two Higgs doublet model without a $Z_2$ symmetry, where the extra Yukawa coupling ${\rho }_{tc}$ generates $tH$ production, with the extra top Yukawa ${\rho }_{tt}\simeq 0$ to avoid $gg\to H$ constraints. We find that discovery is possible for $m_H$ around 300 GeV or so at the LHC, but would need finite $h$-$H$ mixing angle $\cos \gamma$ to allow for finite ${\lambda }_{Hhh}$ coupling, and ${\rho }_{tc}$ also needs to be not too small. A sizable ${\rho }_{tc}$ could drive electroweak baryogenesis, which further motivates the search.

   hep-phhep-exPRD(2019)·15 citations
4. 04*

   Sterile Neutrino. A short introduction

   Dmitry V.Naumov🇷🇺

   This is a pedagogical introduction to the main concepts of the sterile neutrino - a hypothetical particle, coined to resolve some anomalies in neutrino data and retain consistency with observed widths of the $W$ and $Z$ bosons. We briefly review existing anomalies and the oscillation parameters that best describe these data. We discuss in more detail how sterile neutrino can be observed, as well as the consequences of its possible existence. In particular, we pay attention to a possible loss of coherence in a model of neutrino oscillations with sterile neutrinos, where this effect might be of a major importance with respect to the 3$\nu$ model. The current status of searches for a sterile neutrino state is also briefly reviewed.

   hep-phEPJ Web Conf.(2019)·19 citations
5. 05*

   Charming Top Decays with Flavor Changing Neutral Higgs Boson and WW at Hadron Colliders

   Rishabh Jain🇺🇸 · Chung Kao🇺🇸

   We investigate the prospects for discovering a top quark decaying into one light Higgs boson ($h^0$) along with a charm quark ($c$) in top quark pair production at the CERN Large Hadron Collider (LHC) and future hadron colliers. A general two Higgs doublet model is adopted to study the signature of flavor changing neutral Higgs (FCNH) interactions with $t\to c{h}^0$, followed by $h^0\to W{W}^{\ast }\to {\ell }^{+}{\ell }^{-}+{\text{notE}}_T$, where $h^0$ is the CP-even Higgs boson and ${\text{notE}}_T$ stands for missing transverse energy from neutrinos. We study the discovery potential for this FCNH signal and physics background from dominant processes with realistic acceptance cuts as well as tagging and mistagging efficiencies. Promising results are found for the LHC running at 13 TeV and 14 TeV center-of-mass energy as well as future pp colliders at 27 TeV and 100 TeV.

   hep-phPRD(2019)·12 citations
6. 06*

   Dynamical quenching weights in an expanding medium

   Souvik Priyam Adhya🇨🇿 · Carlos A. Salgado🇪🇸 · Konrad Tywoniuk🇳🇴

   In this work, we extend the resummation of multiple medium-induced emissions to apply to dynamically expanding media. This is done by recasting the quenching weight as the solution of a rate equation with medium-induced partonic splitting functions that are sensitive to the expansion. We perform the calculations in the framework of Baier-Dokshitzer- Mueller-Peigne-Schiff-Zakharov (BDMPSZ) formalism for multiple soft scatterings with a time-dependent transport coefficient. Furthermore, we discuss the validity of a dynamical scaling law that relates the spectrum in an expanding medium to the equivalent static case with re-scaled medium parameters and test the scaling law for the gluon splitting rates.

   hep-phPoS(2019)·1 citation
7. 07*

   Twist-2 operators induced Dark Matter Interactions

   Hrishabh Bharadwaj🇮🇳 · Sukanta Dutta🇮🇳

   We study the effective interactions of the fermionic, scalar and vector dark matter (DM) with leptons and neutral electroweak gauge Bosons induced by the higher dimensional effective twist-2 tensor operators. We constrain these lepto-philic, ${\tau }^{\pm }$-philic and $U(1{)}_Y$ gauge Boson B-philic effective interactions of DM with the visible world from the WMAP and Planck data. The thermally averaged indirect DM pair annihilation cross-section and the DM-electron direct-detection cross-section for such DM candidates are observed to be consistent with the respective experimental data. Constraining coefficients of the effective operators from the low energy LEP data for the DM $\le$ 80 GeV, we further study their sensitivities in the pair production of such DM $\ge$ 50 GeV in association with mono-photon at the proposed ILC and perform the ${\chi }^2$ analysis to obtain the 99.73\% C.L. acceptance contours in the $m_{\mathrm{DM}}-{\Lambda }_{\mathrm{eff}}$ plane from the two dimensional differential distributions of the kinematic observables. We observe that ILC has rich potential to probe the contribution of such effective operators.

   hep-ph1 citation
8. 08*

   Quantum 3: Learning QCD through Intuitive Play

   Tristan Özkan🇺🇸 · Huey-Wen Lin🇺🇸

   There is a nationwide drive to get more girls into physics and coding, and some educators believe gaming could be a way to get girls interested in coding and STEM topics. This project, sponsored by NSF, is to create a QCD game that will raise public interest in QCD, especially among K-12 girls, and increase interest in coding among girls. Through the immersive framework of interactive gameplay, this QCD phone game will allow the public to peek into the QCD research world. The game design will fall into the "Match 3" genre, which typically attracts a higher ratio of female players. The game will be implemented initially as a phone app, and the gameplay would require learning simple QCD rules to progress. By leveraging the willingness of players to engage with the rules of an entertaining game, they are able to easily learn a few principles of physics. The game is now available to download from the Google Play store (https://play.google.com/store/apps/details?id=com.gellab.quantum3) and the Apple Appstore (https://itunes.apple.com/gb/app/quantum-3/id1406630529)! We formed a development team of MSU undergraduate students to make the game and provided them with a QCD curriculum. The game will be tested at MSU outreach activities, as well as among local K-12 girls through school activities, and feedback will be used to improve the design. The final game can be easily distributed through various app stores and impact will be measured through a follow-up survey. If such a new direction works to attract more girls to coding and physics, one should develop more games to engage more girls in STEM.

   ↳ physics.ed-phhep-exhep-lathep-ph+1PoS(2018)·1 citation
9. 09*

   Matrix model and Yukawa couplings on the noncommutative torus

   Masaki Honda🇯🇵

   The IKKT model is proposed as a non-perturbative formulation of superstring theory. We propose a Dirac operator on the noncommutative torus,which is consistent with the IKKT model, based on noncommutative geometry. Next, we consider zero-mode equations of the Dirac operator with magnetic fluxes. We find that zero-mode solutions have the chirality and the generation structures similar to the commutative case. Moreover, we compute Yukawa couplings of chiral matter fields.

   ↳ hep-thhep-phJHEP(2019)·7 citations
10. 10*

    Comments on the chemical and kinetic equilibration in heavy ion collisions

    E.Shuryak🇺🇸

    I argue that perturbative scattering of quarks and gluons are incompatible with lattice and heavy ion data on QGP properties. The non-perturbative mechanisms for quasiparticle rescattering and quark production are briefly discussed, as well as experiments needed to measure matter anisotropy and quark density at early stages of the collisions.

    ↳ nucl-thhep-ph2 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.