Fri·Dec 27, 2019Friday·December 27, 2019

1. 01*

   Minimal self-interacting dark matter models with light mediator

   Thomas Hambye🇧🇪 · Laurent Vanderheyden🇧🇪

   The light mediator scenario of self-interacting dark matter is strongly constrained in many ways. After summarizing the various constraints, we discuss minimal options and models which allow to nevertheless satisfy all these constraints. One straightforward possibility arises if the dark matter and light mediator particles have a temperature sizably smaller than the SM particles. Another simple possibility arises if dark matter doesn't annihilate dominantly into a pair of light mediators but into heavier particles. Both possibilities are discussed with scalar as well as vector boson light mediators. Further possibilities, such as with a hierarchy of quartic scalar couplings, are also identified.

   hep-phJCAP(2020)·50 citations
2. 02*

   Strong coupling ${\alpha }_s(m_Z)$ extraction from a combined NNLO analysis of inclusive electroweak boson cross sections at hadron colliders

   David d'Enterria🇨🇭 · Andres Poldaru🇩🇪

   The inclusive cross sections of W${}^{+}$, W${}^{-}$, and Z boson production from 34 different measurements performed in proton-(anti)proton collisions at center-of-mass energies $\sqrt{s}$ = 1.8--13 TeV, are compared to perturbative QCD calculations at next-to-next-to-leading-order (NNLO) accuracy with four sets of parton distributions functions (CT14, HERAPDF2.0, MMHT14, and NNPDF3.0 PDFs) and varying values of the strong coupling constant at the Z mass pole, ${\alpha }_s(m_Z)$. The data-theory agreement is good within the experimental and theoretical uncertainties, with the CT14 and MMHT14 parton densities providing the most overall consistent description of all cross section data. A value of ${\alpha }_s(m_Z)=0.1188_{-0.0013}^{+0.0019}$ is extracted from a combined fit of the 28 experimental LHC measurements to the corresponding NNLO theoretical predictions obtained with the MMHT14 PDF set, which provides the most robust and stable QCD coupling extraction of this analysis.

   hep-phhep-exJHEP(2020)·23 citations
3. 03*

   Probing the top Yukawa coupling at the LHC via associated production of single top and Higgs

   Vernon Barger🇺🇸 · Kaoru Hagiwara🇯🇵 · Ya-Juan Zheng🇺🇸

   We study Higgs boson production associated with single top or anti-top via $t$-channel weak boson exchange at the LHC. The process is an ideal probe of the top quark Yukawa coupling, because we can measure the relative phase of $htt$ and $hWW$ couplings, thanks to the significant interference between the two amplitudes. By choosing the emitted $W$ momentum along the polar axis in the $th(\bar{t}h)$ rest frame, we obtain the helicity amplitudes for all the contributing subprocesses analytically, with possible CP phase of the Yukawa coupling. We study the azimuthal asymmetry between the $W$ emission and the $Wb(\bar{b})\to t(\bar{t})h$ scattering planes, as well as several $t$ and $\bar{t}$ polarization asymmetries as a signal of CP violating phase in the $htt$ coupling. Both the azimuthal asymmetry and the polarization perpendicular to the scattering plane are found to have the opposite sign between the top and anti-top events. We identify the origin of the sign of asymmetries, and propose the possibility of direct CP violation test in $pp$ collisions by comparing the top and anti-top polarization at the LHC.

   hep-phJHEP(2020)·12 citations
4. 04*

   Triply charmed and bottom baryons in a constituent quark model

   Ming-Sheng Liu🇨🇳 · Qi-Fang Lü🇨🇳 · Xian-Hui Zhong🇨🇳

   In this work, we study the mass spectrum of the ${\Omega }_{ccc}$ and ${\Omega }_{bbb}$ baryons up to the $N=2$ shell within a nonrelativistic constituent quark model (NRCQM). The model parameters are adopted from the determinations by fitting the charmonium and bottomonium spectra in our previous works. The masses of the ${\Omega }_{ccc}$ and ${\Omega }_{bbb}$ baryon states predicted in present work reasonably agree with the results obtained with the Lattice QCD calculations. Furthermore, to provide more knowledge of the ${\Omega }_{ccc}$ and ${\Omega }_{bbb}$ states, we evaluate their radiative decays with the available masses and wave functions from the potential model.

   hep-phPRD(2020)·46 citations
5. 05*

   Triangle singularity appearing as an $X(3872)$-like peak in $B\to (J/\psi {\pi }^{+}{\pi }^{-})K\pi$

   Satoshi X. Nakamura (University of Science and Technology of China)🇨🇳

   We consider a triangle diagram for $B^0\to (J/\psi {\pi }^{+}{\pi }^{-})K^{+}{\pi }^{-}$ where an $X(3872)$ peak has been observed experimentally. We demonstrate that a triangle singularity inherent in the triangle diagram creates a sharp peak in the $J/\psi {\pi }^{+}{\pi }^{-}$ invariant mass distribution when the final $(J/\psi {\pi }^{+}{\pi }^{-})\pi$ invariant mass is at and around the $D^{\ast }{\bar{D}}^{\ast }$ threshold. The position and width of the peak is 3871.68 MeV (a few keV above the $D^{\ast 0}{\bar{D}}^0$ threshold) and $\sim$0.4 MeV, respectively, in perfect agreement with the precisely measured $X(3872)$ mass and width: $3871.69\pm 0.17$ MeV and $<1.2$ MeV. This remarkable agreement is virtually parameter-free. The result indicates that the considered mechanism has to be understood in advance when separating an $X(3872)$-pole contribution from $B^0\to (J/\psi {\pi }^{+}{\pi }^{-})K^{+}{\pi }^{-}$ data; the separation yields an $X(3872)\pi$ lineshape that could be used to determine the $X(3872)$ mass. We suggest a method to set a constraint on the triangle mechanism by analyzing a charge analogous process $B^0\to (J/\psi {\pi }^0{\pi }^{-})K^{+}{\pi }^0$ where a similar triangle singularity generates an $X^{-}(3876)$-like peak.

   hep-phhep-exnucl-thPRD(2020)·23 citations
6. 06*

   Studying the localized $CP$ violation and the branching fraction of the ${\bar{B}}^0\to K^{-}{\pi }^{+}{\pi }^{+}{\pi }^{-}$ decay

   Jing-Juan Qi🇨🇳 · Zhen-Yang Wang🇨🇳 · Jing Xu🇨🇳 · Xin-Heng Guo🇨🇳

   In this work, we study the localized $CP$ violation and the branching fraction of the four-body decay ${\bar{B}}^0\to K^{-}{\pi }^{+}{\pi }^{-}{\pi }^{+}$ by employing a quasi-two-body QCD factorization approach. Considering the interference of ${\bar{B}}^0\to {\bar{K}}_0^{\ast }(700){\rho }^0(770)\to K^{-}{\pi }^{+}{\pi }^{-}{\pi }^{+}$ and ${\bar{B}}^0\to {\bar{K}}^{\ast }(892)f_0(500)\to K^{-}{\pi }^{+}{\pi }^{-}{\pi }^{+}$ channels, we predict ${\mathcal{A}}_{\mathcal{C}\mathcal{P}}({\bar{B}}^0\to K^{-}{\pi }^{+}{\pi }^{-}{\pi }^{+})\in [0.15,0.28]$ and $\mathcal{B}({\bar{B}}^0\to K^{-}{\pi }^{+}{\pi }^{-}{\pi }^{+})\in [1.73,5.10]\times 10^{-7}$, respectively, which shows that this two channels' interference mechanism can induce the localized $CP$ violation to this four-body decay. Meanwhile, within the two quark model framework for the scalar mesons $f_0(500)$ and ${\bar{K}}_0^{\ast }(700)$, we calculate the direct CP violations and branching fractions of the ${\bar{B}}^0\to {\bar{K}}_0^{\ast }(700){\rho }^0(770)$ and ${\bar{B}}^0\to {\bar{K}}^{\ast }(892)f_0(500)$ decays, respectively. The corresponding results are ${\mathcal{A}}_{\mathcal{C}\mathcal{P}}({\bar{B}}^0\to {\bar{K}}_0^{\ast }(700){\rho }^0(770))\in [0.20,0.36]$, ${\mathcal{A}}_{\mathcal{C}\mathcal{P}}({\bar{B}}^0\to {\bar{K}}^{\ast }(892)f_0(500))\in [0.08,0.12]$, $\mathcal{B}({\bar{B}}^0\to {\bar{K}}_0^{\ast }(700){\rho }^0(770)\in [6.76,18.93]\times 10^{-8}$ and $\mathcal{B}({\bar{B}}^0\to {\bar{K}}^{\ast }(892)f_0(500))\in [2.66,4.80]\times 10^{-6}$, respectively, indicating the $CP$ violations of these two two-body decays are both positive and the branching fractions are quite different. These studies provide a new way to investigate the aforementioned four-body decay and could be helpful in clarifying the configuration of the structure of light scalar meson.

   hep-ph8 citations
7. 07*

   Future Prospects for the Minimal Supersymmetric Standard Model

   Shehu AbdusSalam🇮🇷 · Safura Sadeghi Barzani🇮🇷 · Mohammadreza Noormandipour🇮🇷

   Experimental collaborations for the large hadron collider conducted many and various searches for supersymmetry. In the absence of signals, lower limits were put on sparticle masses but usually within frameworks with (over-) simplifications relative to the entire indications by supersymmetry models. For complementing current interpretations of experimental bounds, we introduce a 30-parameters version of the R-parity conserving minimal supersymmetric standard model (MSSM-30). Using a sample of the MSSM-30 which are in harmony with cold dark matter, flavour and precision electroweak constraints, we explicitly show the prospects for assessing neutralino candidate dark matter in contrast to future searches for supersymmetry. The MSSM-30 parameters regions that are beyond reach to dark matter direct detection experiments could be probed by future hadron-hadron colliders.

   hep-phhep-exInt.J.Mod.Phys.A(2021)·6 citations
8. 08*

   What can a heavy $U(1{)}_{\mathrm{B}-\mathrm{L}}$ $Z^{\prime }$ boson do to the muon $(g-2{)}_{\mu }$ anomaly and to a new Higgs boson mass?

   António P. Morais🇵🇹 · Roman Pasechnik🇸🇪 · J. Pedro Rodrigues🇵🇹

   The minimal $U(1{)}_{\mathrm{B}-\mathrm{L}}$ extension of the Standard Model (B-L-SM) offers an explanation for neutrino mass generation via a seesaw mechanism as well as contains two new physics states such as an extra Higgs boson and a new $Z^{\prime }$ gauge boson. The emergence of a second Higgs particle as well as a new $Z^{\prime }$ gauge boson, both linked to the breaking of a local $U(1{)}_{\mathrm{B}-\mathrm{L}}$ symmetry, makes the B-L-SM rather constrained by direct searches at the Large Hadron Collider (LHC) experiments. We investigate the phenomenological status of the B-L-SM by confronting the new physics predictions with the LHC and electroweak precision data. Taking into account the current bounds from direct LHC searches, we demonstrate that the prediction for the muon $(g-2{)}_{\mu }$ anomaly in the B-L-SM yields at most a contribution of approximately $8.9\times 10^{-12}$ which represents a tension of $3.28$ standard deviations, with the current $1\sigma$ uncertainty, by means of a $Z^{\prime }$ boson if its mass lies in a range of $6.3$ to $6.5$ TeV, within the reach of future LHC runs. This means that the B-L-SM, with heavy yet allowed $Z^{\prime }$ boson mass range, in practice does not resolve the tension between the observed anomaly in the muon $(g-2{)}_{\mu }$ and the theoretical prediction in the Standard Model. Such a heavy $Z^{\prime }$ boson also implies that the minimal value for a new Higgs mass is of the order of 400 GeV.

   hep-phhep-exCPC(2021)·2 citations
9. 09*

   $B\to D^{(\ast )}\ell \nu$ form factors from lattice QCD with relativistic heavy quarks

   T. Kaneko🇯🇵 · Y. Aoki🇯🇵 · G. Bailas🇯🇵 · B. Colquhoun🇺🇸 · H. Fukaya🇯🇵 · S. Hashimoto🇯🇵 · J. Koponen (JLQCD Collaboration)🇯🇵

   We report on our calculation of the B \to D^(*) \ell \nu form factors in 2+1 flavor lattice QCD. The Möbius domain-wall action is employed for light, strange, charm and bottom quarks. At lattice cutoffs 1/a \sim 2.4, 3.6 and 4.5 GeV, we simulate bottom quark masses up to 0.7/a to control discretization errors. The pion mass is as low as 230 MeV. We extrapolate the form factors to the continuum limit and physical quark masses, and make a comparison with recent phenomenological analyses.

   ↳ hep-lathep-phPoS(2019)·30 citations
10. 10*

    Circular and Linear ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ Colliders: Another Story of Complementarity

    Alain Blondel🇫🇷 · Patrick Janot🇨🇭

    The remarkable synergy and complementarity between the circular ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ and pp colliders has been extensively discussed. In this short document, we investigate the complementarity between the proposed circular and linear ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ colliders at the electroweak and TeV scale. This complementarity could be exploited on a world-wide scale, if both a large circular and a linear infrastructures were available. A possible implementation of such a complementary program is shown.

    ↳ hep-exhep-ph23 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.