HEP Phenomenology·hep-ph

Mon·Jul 22, 2019Monday·July 22, 2019

18 papers—15 primary·3 cross-listed·reconstructed*

01*
Matching coefficients in NRQCD to two-loop accuracy
Marvin Gerlach🇩🇪 · Go Mishima🇩🇪 · Matthias Steinhauser🇩🇪
We consider the Lagrange density of non-relativistic Quantum Chromodynamics expanded up to order $1/ m^{2}$ , where $m$ is the heavy quark mass, and compute several matching coefficients up to two-loop order. Our results are building blocks for next-to-next-to-next-to-leading logarithmic and next-to-next-to-next-to-next-to-leading order corrections to the threshold production of top quark pairs and the decay of heavy quarkonia. We describe the techniques used for the calculation and provide analytic results for a general covariant gauge.
hep-phPRD(2019)·17 citations
02*
Dark matter in Inert Doublet Model with one scalar singlet and $U (1)_{X}$ gauge symmetry
M. A. Arroyo-Ureña🇲🇽 · R. Gaitan🇲🇽 · R. Martinez🇨🇴 · J. H. Montes de Oca Yemha🇲🇽
We study Dark Matter (DM) abundance in the framework of the extension of the Standard Model (SM) with an additional $U (1)_{X}$ gauge symmetry. One complex singlet is included to break the $U (1)_{X}$ gauge symmetry, meanwhile one of the doublets is considered inert to introduce a DM candidate. The stability of the DM candidate is analyzed with a continuous $U (1)_{X}$ gauge symmetry as well as discrete $Z_{2}$ symmetry. We find allowed regions for the free model parameters which are in agreement with the most up-to-date experimental results reported by CMS and ATLAS collaborations, the upper limit on WIMP-nucleon cross section imposed by XENON1T collaboration and the upper limit on the production cross-section of a $Z^{'}$ gauge boson times the branching ratio of the $Z^{'}$ boson decaying into $ℓ^{-} ℓ^{+}$ . We also obtain allowed regions for the DM candidate mass from the relic density reported by the PLANCK collaboration including light, intermediate and heavy masses; depending mainly on two parameters of the scalar potential, $λ_{2 x}$ and $λ_{345} = λ_{3} + λ_{4} + 2 λ_{5}$ . We find that trough $pp \to χχ γ$ production, it may only be possible for a future hadron-hadron Circular Collider (FCC-hh) to be able to detect a DM candidate within the range of masses 10-60 GeV.
hep-phEPJC(2020)·8 citations
03*
Resonant Assisted Annihilation
Tarak Nath Maity🇮🇳 · Tirtha Sankar Ray🇮🇳
Assisted annihilation is a novel mechanism to generate viable sub-GeV thermal dark matter, where a pair of stable dark matter annihilates with an assister to Standard Model states. Typically such $3 \to 2$ annihilation topologies are flux suppressed compared to $2 \to 2$ processes. In this paper, we explore the possibility of a resonant $3 \to 2$ assisted annihilation dominantly driving the freeze-out of dark matter. We demonstrate that in a simple multipartite scalar extension of the Standard Model this can be realized in certain regions of parameter space to provide viable dark matter relic density, in agreement with observation. We demonstrate that for photophilic assisters parts of the parameter space are already constrained by indirect detection experiments and the measurements of CMB anisotropies while substantial regions remain beyond the present limit.
hep-phJCAP(2019)·9 citations
04*
Forward-Backward Drell-Yan Asymmetry and PDF Determination
H Abdolmaleki🇮🇷 · E Accomando🇬🇧 · V Bertone · J Fiaschi🇩🇪 · F Giuli🇮🇹 · A Glazov🇩🇪 · F Hautmann🇧🇪 · A Luszczak🇵🇱 · S Moretti🇬🇧 · I Novikov · F Olness🇺🇸 · O Zenaiev🇩🇪
We investigate the impact of high-statistics Drell-Yan (DY) measurements at the LHC on the study of non-perturbative QCD effects from parton distribution functions (PDF). We present the results of a PDF profiling analysis based on the neutral-current DY forward-backward asymmetry, using the open source fit platform xFitter.
hep-ph8 citations
05*
White Paper on New Opportunities at the Next-Generation Neutrino Experiments (Part 1: BSM Neutrino Physics and Dark Matter)
C.A. Argüelles🇺🇸 · A.J. Aurisano🇺🇸 · B. Batell🇺🇸 · J. Berger🇺🇸 · M. Bishai🇺🇸 · T. Boschi🇬🇧 · N. Byrnes🇺🇸 · A. Chatterjee🇺🇸 · A. Chodos🇺🇸 · T. Coan🇺🇸 · Y. Cui🇺🇸 · A. de Gouvêa🇺🇸 and 38 other authors
With the advent of a new generation of neutrino experiments which leverage high-intensity neutrino beams for precision measurements, it is timely to explore physics topics beyond the standard neutrino-related physics. Given that the realm of beyond the standard model (BSM) physics has been mostly sought at high-energy regimes at colliders, such as the LHC at CERN, the exploration of BSM physics in neutrino experiments will enable complementary measurements at the energy regimes that balance that of the LHC. This is in concert with new ideas for high-intensity beams for fixed target and beam-dump experiments world-wide, e.g., those at CERN. The combination of the high intensity proton beam facilities and massive detectors for precision neutrino oscillation parameter measurements and for CP violation phase measurements will help make BSM physics reachable even in low energy regimes in accelerator based experiments. Large mass detectors with highly precise tracking and energy measurements, excellent timing resolution, and low energy thresholds will enable searches for BSM phenomena from cosmogenic origin, as well. Therefore, it is conceivable that BSM topics in the next generation neutrino experiments could be the dominant physics topics in the foreseeable future, as the precision of the neutrino oscillation parameter and CPV measurements continues to improve. In this spirit, this white paper provides a review of the current landscape of BSM theory in neutrino experiments in two selected areas of the BSM topics - dark matter and neutrino related BSM - and summarizes the current results from existing neutrino experiments to set benchmarks for both theory and experiment. This paper then provides a review of upcoming neutrino experiments throughout the next 10 - 15 year time scale and their capabilities to set the foundation for potential reach in BSM physics in the two aforementioned themes.
hep-phhep-exRept.Prog.Phys.(2020)·127 citations
06*
Charged current $b \to c τ ν ˉ_{τ}$ anomalies in a general $W^{'}$ boson scenario
John D. Gomez🇨🇴 · Néstor Quintero🇨🇴 · Eduardo Rojas🇨🇴
Very recent experimental information obtained from the Belle experiment, along with that accumulated by the BABAR and LHCb experiments, has shown the existence of anomalies in the ratios $R (D)$ and $R (D^{*})$ associated with the charged-current transition $b \to c τ ν ˉ_{τ}$ . Although the Belle measurements are in agreement with the standard model (SM) predictions, the new experimental world averages still exhibit a tension. In addition, the $D^{*}$ longitudinal polarization $F_{L} (D^{*})$ related with the channel $B \to D^{*} τ ν ˉ_{τ}$ observed by the Belle Collaboration and the ratio $R (J / ψ)$ measured by the LHCb Collaboration also show discrepancies with their corresponding SM estimations. We present a model-independent study based on the most general effective Lagrangian that yields a tree-level effective contribution to the transition $b \to c τ ν ˉ_{τ}$ induced by a general $W^{'}$ boson. Instead of considering any specific new physics (NP) realization, we perform an analysis by considering all of the different chiral charges to the charm-bottom and $τ$ - $ν_{τ}$ interaction terms with a charged $W^{'}$ boson that explain the anomalies. We present a phenomenological study of parameter space allowed by the new experimental $b \to c τ ν ˉ_{τ}$ data and with the mono-tau signature $pp \to τ_{h} X + MET$ at the LHC. For comparison, we include some of the $W^{'}$ boson NP realizations that have already been studied in the literature.
hep-phhep-exPRD(2019)·55 citations
07*
Dark Matter Spin Characterisation in Mono- $Z$ Channels
W. Abdallah🇮🇳 · A. Hammad🇨🇭 · S. Khalil🇪🇬 · S. Moretti🇬🇧
The $B - L$ Supersymmetric Standard Model (BLSSM) is an ideal testing ground of the spin nature of Dark Matter (DM) as it offers amongst its candidates both a spin-1/2 (the lightest neutralino) and spin-0 (the lightest right-handed sneutrino) state. We show that the mono- $Z$ channel can be used at the Large Hadron Collider (LHC) to diagnose whether a DM signal is characterised within the BLSSM by a fermionic or (pseudo)scalar DM particle. Sensitivity to either hypothesis can be obtained after only 100 fb $^{- 1}$ of luminosity following Runs 2 and 3 of the LHC.
hep-phhep-exPRD(2019)·7 citations
08*
Does the Wolfenstein form work for the leptonic mixing matrix?
G. Rajasekaran🇮🇳
Starting with the Wolfenstein form for the leptonic mixing matrix we show that renormaliztion group evolution brings that to the observed large mixing at low energies.
hep-ph1 citation
09*
$B ˉ_{s} \to f_{0} (980)$ form factors and the width effect from light-cone sum rules
Shan Cheng🇨🇳 · Jian-Ming Shen🇨🇳
In this paper we calculate the $B ˉ_{s} \to f_{0} (980)$ form factors from light-cone sum rules with $B$ meson DAs. With adopting the quark-antiquark configuration of light scalar mesons,the high twist two-particle and the three-particle contributions are found to be $\sim 25%$ individual, and totally they give about $50%$ correction to certain form factors in the considered energy regions. We further explore the light-cone sum rules approach to study the $S -$ wave $B ˉ_{s} \to K K$ form factors,the $f_{0} + f_{0}^{'} + f_{0}^{''}$ resonance model is proposed and the result shows that the background effect from $f_{0}^{'} + f_{0}^{''}$ accounts $\sim 5%$ . As a by-product, we extract the strong coupling $∣ g_{f_{0} K K} ∣ = 1.0 8_{- 0.14}^{+ 0.05}$ GeV with taking the $B ˉ_{s} \to f_{0} (980)$ form factors calculated previous under the narrow width approximation.
hep-phEPJC(2020)·35 citations
10*
New way to access the quark fragmentation functions in electron-positron annihilation
Aram Kotzinian🇦🇲 · Hrayr H. Matevosyan🇦🇺 · Anthony W. Thomas🇦🇺
The description of the polarized quark hadronization process is one of the most challenging problems in the physics of strong interactions. The various single hadron and dihadron fragmentation functions, that quantify this process, are determined by analyzing the inclusive production of hadrons in electron-positron semi-inclusive annihilation process (SIA). These, in turn, are used to extract the transverse momentum dependent parton distribution functions from the experiments on semi-inclusive deep inelastic scattering process (SIDIS), elucidating the spin-orbit correlations in nucleon. Here we present a framework for new measurements of polarized quark fragmentation functions in electron-positron annihilation and deep inelastic semi-inclusive processes. These measurements offer a number of exciting opportunities to improve our understanding of the polarized quark hadronization and test the universality of the fragmentation functions. Such measurements can be performed at the upcoming BELLE II, JLab-12 and the future EIC experiments
hep-phhep-exPoS(2019)·1 citation
11*
Exclusive production of a large mass photon pair
A. Pedrak🇵🇱 · B. Pire🇫🇷 · L. Szymanowski🇵🇱 · J. Wagner🇵🇱
The scattering amplitude for photoproduction of a large invariant mass diphoton in the generalized Bjorken regime has a very peculiar and interesting analytical structure. The leading twist leading order amplitude is proportional to valence quark generalized parton distributions taken at the border value $x = \pm ξ$ . Cross section estimates show that this process is measurable at JLab energies. The angular asymmetry triggered by a linearly polarized photon beam is large.
hep-phhep-exnucl-exnucl-thPoS(2019)·0 citations
12*
The Dynamical Diquark Model: Fine Structure and Isospin
Jesse F. Giron🇺🇸 · Richard F. Lebed🇺🇸 · Curtis T. Peterson🇺🇸
We incorporate fine-structure corrections into the dynamical diquark model of multiquark exotic hadrons. These improvements include effects due to finite diquark size, spin-spin couplings within the diquarks, and most significantly, isospin-dependent couplings in the form of pionlike exchanges assumed to occur between the light quarks within the diquarks. Using a simplified two-parameter interaction Hamiltonian, we obtain fits in which the isoscalar $J^{P C} = 1^{++}$ state---identified as the $X (3872)$ ---appears naturally as the lightest exotic (including all states that are predicted by the model but have not yet been observed), while the $Z_{c} (3900)$ and $Z_{c} (4020)$ decay predominantly to $J / ψ$ and $η_{c}$ , respectively, in accord with experiment. We explore implications of this model for the excited tetraquark multiplets and the pentaquarks.
hep-phJHEP(2020)·33 citations
13*
Parton distributions from nonlocal chiral SU(3) effective theory: Flavor asymmetries
Y. Salamu🇨🇳 · Chueng-Ryong Ji🇺🇸 · W. Melnitchouk🇺🇸 · A. W. Thomas🇦🇺 · P. Wang🇨🇳 · X. G. Wang🇦🇺
Using recently derived results for one-loop hadronic splitting functions from a nonlocal implementation of chiral effective theory, we study the contributions from pseudoscalar meson loops to flavor asymmetries in the proton. Constraining the parameters of the regulating functions by inclusive production of $n$ , $Δ^{++}$ , $Λ$ and $Σ^{*+}$ baryons in $pp$ collisions, we compute the shape of the light antiquark asymmetry $d ˉ - u ˉ$ in the proton and the strange asymmetry $s - s ˉ$ in the nucleon sea. With these constraints, the magnitude of the $d ˉ - u ˉ$ asymmetry is found to be compatible with that extracted from the Fermilab E866 Drell-Yan measurement, with no indication of a sign change at large values of $x$ , and an integrated value in the range $⟨ d ˉ - u ˉ ⟩ \approx 0.09 - 0.17$ . The $s - s ˉ$ asymmetry is predicted to be positive at $x > 0$ , with compensating negative contributions at $x = 0$ , and an integrated $x$ -weighted moment in the range $⟨ x (s - s ˉ)⟩ \approx (0.9 - 2.5) \times 1 0^{- 3}$ .
hep-phhep-exnucl-thPRD(2019)·27 citations
14*
Discovery and spectroscopy of dark matter and dark sectors with microscopic black holes at next generation colliders
Ningqiang Song🇨🇦 · Aaron C. Vincent🇨🇦
If the length scale of possible extra dimensions is large enough, the effective Planck scale is lowered such that microscopic black holes could be produced in collisions of high-energy particles at colliders. These black holes evaporate through Hawking radiation of a handful of energetic particles drawn from the set of all kinematically and thermally allowed degrees of freedom, including dark matter. Here, we perform the first numerical black hole spectroscopic study of the dark sector. We find that if the next generation of colliders can produce microscopic black holes, then missing momentum signatures can reveal the existence of any new light ( $≲ 10$ TeV) particle, regardless of the strength of its coupling to the Standard Model, even if there exists no such non-gravitational coupling at all.
hep-phPRL(2020)·9 citations
15*
Systematic classification of two loop d = 4 Dirac neutrino mass models and the Diracness-dark matter stability connection
Salvador Centelles Chuliá🇪🇸 · Ricardo Cepedello🇪🇸 · Eduardo Peinado🇲🇽 · Rahul Srivastava🇪🇸
We provide a complete systematic classification of all two-loop realizations of the dimension four operator for Dirac neutrino masses. Our classification is multi-layered, starting first with a classification in terms of all possible distinct two-loop topologies. Then we discuss the possible diagrams for each topology. Model-diagrams originating from each diagram are then considered. The criterion for genuineness is also defined and discussed at length. Finally, as examples, we construct two explicit models which also serve to highlight the intimate connection between the Dirac nature of neutrinos and dark matter stability.
hep-phJHEP(2019)·51 citations
16*
Spontaneous symmetry breaking and Nambu-Goldstone modes in open classical and quantum systems
Yoshimasa Hidaka🇯🇵 · Yuki Minami🇨🇳
We discuss spontaneous symmetry breaking of open classical and quantum systems. When a continuous symmetry is spontaneously broken in an open system, a gapless excitation mode appears corresponding to the Nambu-Goldstone mode. Unlike isolated systems, the gapless mode is not always a propagation mode, but it is a diffusion one. Using the Ward-Takahashi identity and the effective action formalism, we establish the Nambu-Goldstone theorem in open systems, and derive the low-energy coefficients that determine the dispersion relation of Nambu-Goldstone modes. Using these coefficients, we classify the Nambu-Goldstone modes into four types: type-A propagation, type-A diffusion, type-B propagation, and type-B diffusion modes.
↳ hep-thcond-mat.mes-hallcond-mat.quant-gashep-phPTEP(2020)·28 citations
17*
Impact of DCSB and dynamical diquark correlations on proton GPDs
Adam Freese🇺🇸 · Ian C. Cloët🇺🇸
We calculate the leading-twist, helicity-independent generalized parton distributions (GPDs) of the proton, at finite skewness, in the Nambu--Jona-Lasinio (NJL) model of quantum chomodynamics (QCD). The NJL model reproduces low-energy characteristics of QCD, including dynamical chiral symmetry breaking (DCSB). The proton bound-state amplitude is solved for using the Faddeev equation in a quark-diquark approximation, including both dynamical scalar and axial vector diquarks. GPDs are calculated using a dressed non-local correlator, consistent with DCSB, which is obtained by solving a Bethe-Salpeter equation. The model and approximations used observe Lorentz covariance, and as a consequence the GPDs obey polynomiality sum rules. Extractions of electromagnetic and gravitational form factors are performed. We find a D-term of $- 1.08$ when the non-local correlator is properly dressed, and $0.85$ when the bare correlator is used instead, suggesting that within this framework proton stability requires the constituent quarks to be dressed consistently with DCSB. We also find that the anomalous gravitomagnetic vanishes, as required by Poincaré symmetry.
↳ nucl-thhep-phPRC(2020)·21 citations
18*
Effective Lagrangian for Nambu-Goldstone modes in nonequilibrium open systems
Masaru Hongo🇯🇵 · Suro Kim🇯🇵 · Toshifumi Noumi🇯🇵 · Atsuhisa Ota🇬🇧
We develop the effective field theory of diffusive Nambu-Goldstone (NG) modes associated with spontaneous internal symmetry breaking taking place in nonequilibrium open systems. The effective Lagrangian describing semi-classical dynamics of the NG modes is derived and matching conditions for low-energy coefficients are also investigated. Due to new terms peculiar to open systems, the associated NG modes show diffusive gapless behaviors in contrast to the propagating NG mode in closed systems. We demonstrate two typical situations relevant to the condensed matter physics and high-energy physics, where diffusive type-A or type-B NG modes appear.
↳ hep-thcond-mat.quant-gascond-mat.stat-mechhep-ph+1PRD(2021)·38 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.