HEP Phenomenology·hep-ph

Mon·Nov 19, 2018Monday·November 19, 2018

16 papers—13 primary·3 cross-listed·reconstructed*

01*
Self-Interacting Dark Matter With a Neutrinophilic Scalar Mediator
Arvind Rajaraman🇺🇸 · Jordan Smolinsky🇺🇸
We examine the phenomenology of a simplified model of fermionic dark matter coupled to a light scalar mediator carrying lepton number 2. We find that the mediator can be very light and still consistent with laboratory and cosmological bounds. This model satisfies the thermal relic condition for natural values of dimensionless coupling constants and admits a mediator in the $10 - 100 MeV$ mass range favored by small scale structure observations. As such, this model provides an excellent candidate for self-interacting dark matter.
hep-phActa Phys.Polon.B(2020)·4 citations
02*
Confronting hadronic tau decays with non-leptonic kaon decays
Antonio Rodríguez Sánchez🇸🇪 · Antonio Pich🇪🇸
In the chiral limit, the $D = 6$ contribution to the Operator Product Expansion (OPE) of the $VV - AA$ correlator of quark currents only depends on two vacuum condensates, which can be related to hadronic matrix elements associated to CP violation in non-leptonic kaon decays. We use those relations to determine $⟨(π π)_{I = 2} ∣ Q_{8} ∣ K ⟩$ , using the updated ALEPH spectral functions. Alternatively, we use those relations in the opposite direction. Taking the values of the matrix elements from the lattice to obtain the $D = 6$ vacuum elements provides a new short-distance constraint which allows for an inclusive determination of $f_{π}$ and an updated value for the $D = 8$ condensate.
hep-phNucl.Part.Phys.Proc.(2018)·3 citations
03*
Correlation observables in $Υ D$ pair production at the LHC within the parton Reggeization approach
Anton Karpishkov🇷🇺 · Maxim Nefedov🇷🇺 · Vladimir Saleev🇷🇺
We study angular correlations in associated hadroproduction of $Υ (1 S)$ with the $D^{\pm}$ and $D^{0}$ -mesons at the LHC in the Leading Order of the parton Reggeization approach. Hadronization of $b b ˉ$ -pair to $Υ (1 S)$ is described within the NRQCD-factorization framework. Production of $D -$ mesons is described in the fragmentation model with scale-dependent fragmentaion functions. We have found good agreement with LHCb data for various differential distributions, except for the case of spectra on azimuthal angle differences at the small $△ φ$ values. The total cross-section in our Single Parton Scattering model, calculated under conservative assumptions, accounts for almost one half of observed cross-section, thus dramatically shrinking the room for Double Parton Scattering mechanism.
hep-phPhys.Part.Nucl.Lett.(2019)·0 citations
04*
Muon-electron scattering at NLO
Massimo Alacevich🇮🇹 · Carlo M. Carloni Calame🇮🇹 · Mauro Chiesa🇩🇪 · Guido Montagna🇮🇹 · Oreste Nicrosini🇮🇹 · Fulvio Piccinini🇮🇹
We consider the process of muon-electron elastic scattering, which has been proposed as an ideal framework to measure the running of the electromagnetic coupling constant at space-like momenta and determine the leading-order hadronic contribution to the muon $g - 2$ (MUonE experiment). We compute the next-to-leading (NLO) contributions due to QED and purely weak corrections and implement them into a fully differential Monte Carlo event generator, which is available for first experimental studies. We show representative phenomenological results of interest for the MUonE experiment and examine in detail the impact of the various sources of radiative corrections under different selection criteria, in order to study the dependence of the NLO contributions on the applied cuts. The study represents the first step towards the realisation of a high-precision Monte Carlo code necessary for data analysis.
hep-phhep-exJHEP(2019)·65 citations
05*
$π - N$ Drell-Yan process in TMD factorization
Xiaoyu Wang🇨🇳 · Zhun Lu🇨🇳
This article presents the review of the current understanding on the pion-nucleon Drell-Yan process from the point of view of the TMD factorization. Using the evolution formalism for the unpolarized and polarized TMD distributions developed recently, we provide the theoretical expression of the relevant physical observables, namely, the unpolarized cross section, the Sivers asymmetry, and the $cos 2 ϕ$ asymmetry contributed by the double Boer-Mulders effects. The corresponding phenomenology, particularly at the kinematical configuration of the COMPASS $π N$ Drell-Yan facility, is displayed numerically.
hep-phhep-exAdv.High Energy Phys.(2019)·1 citation
06*
Vacuum structure of the left-right symmetric model
P.S. Bhupal Dev🇺🇸 · Rabindra N. Mohapatra🇺🇸 · Werner Rodejohann🇩🇪 · Xun-Jie Xu🇩🇪
The left-right symmetric model (LRSM), originally proposed to explain parity violation in low energy processes, has since emerged as an attractive framework for light neutrino masses via the seesaw mechanism. The scalar sector of the minimal LRSM consists of an $S U (2)$ bi-doublet, as well as left- and right-handed weak isospin triplets, thus making the corresponding vacuum structure much more complicated than that of the Standard Model. In particular, the desired ground state of the Higgs potential should be a charge conserving, and preferably global, minimum with parity violation at low scales. We show that this is not a generic feature of the LRSM potential and happens only for a small fraction of the parameter space of the potential. We also analytically study the potential for some simplified cases and obtain useful conditions (though not necessary) to achieve successful symmetry breaking. We then carry out a detailed statistical analysis of the minima of the Higgs potential using numerical minimization and find that for a large fraction of the parameter space, the potential does not have a good vacuum. Imposing the analytically obtained conditions, we can readily find a small part of the parameter space with good vacua. Consequences for some scalar masses are also discussed.
hep-phJHEP(2019)·54 citations
07*
$τ$ decay into a pseudoscalar and an axial-vector meson
L. R. Dai🇨🇳 · L. Roca🇪🇸 · E. Oset🇪🇸
We study theoretically the decay $τ^{-} \to ν_{τ} P^{-} A$ , with $P^{-}$ a $π^{-}$ or $K^{-}$ and $A$ an axial-vector resonance $b_{1} (1235)$ , $h_{1} (1170)$ , $h_{1} (1380)$ , $a_{1} (1260)$ , $f_{1} (1285)$ or any of the two poles of the $K_{1} (1270)$ . The process proceeds through a triangle mechanism where a vector meson pair is first produced from the weak current and then one of the vectors produces two pseudoscalars, one of which reinteracts with the other vector to produce the axial resonance. For the initial weak hadronic production we use a recent formalism to account for the hadronization after the initial quark-antiquark pair produced from the weak current, which explicitly filters G-parity states and obtain easy analytic formulas after working out the angular momentum algebra. The model also takes advantage of the chiral unitary theories to evaluate the vector-pseudoscalar amplitudes, where the axial-vector resonances were obtained as dynamically generated from the VP interaction. We make predictions for invariant mass distribution and branching ratios for the channels considered.
hep-phPRD(2019)·21 citations
08*
Two-photon exchange in nonrelativistic approximation
Dmitry Borisyuk🇺🇦 · Alexander Kobushkin🇺🇦
We calculate two-photon exchange amplitudes for the elastic electron-hadron scattering in the nonrelativistic approximation, and obtain analytical formulae for them. Numerical calculations are performed for proton and $^{3}$ He targets. Comparing our numerical results with relativistic calculations, we find that the real part of the amplitude is described well at moderate $Q^{2}$ , but the imaginary part strongly differs from the relativistic result. Thus the nonrelativistic approximation should not be used for calculation of observables which depend on the imaginary part of the amplitude, such as single-spin asymmetries.
hep-ph1 citation
09*
Angular decorrelations in $γ + 2 j e t$ events at high energies in the parton Reggeization approach
Anton Karpishkov🇷🇺 · Vladimir Saleev🇷🇺 · Alexandra Shipilova🇷🇺
We study associated production of prompt photon and two jets at high energies in the framework of the parton Reggeization approach, which is based on multi-Regge factorization of hard processes and Lipatov's effective theory of Reggeized gluons and quarks. In this approach, initial-state off-shell effects and transverse momenta of initial partons are included in a gauge-invariant way. We compute azimuthal angle difference spectra in $γ + 2 j e t s$ events and compare results with data from D0 Collaboration at the Tevatron. It was found that agreement between predictions and data can be achieved only under assumption on strong violation in transverse momentum ordering during initial-state QCD evolution which corresponds multi-Regge kinematical regime instead of DGLAP picture.
hep-phMod.Phys.Lett.A(2019)·4 citations
10*
Exploring Inert Scalars at CLIC
Jan Kalinowski🇵🇱 · Wojciech Kotlarski🇩🇪 · Tania Robens🇭🇷 · Dorota Sokolowska🇵🇱 · Aleksander Filip Zarnecki🇵🇱
We investigate the prospect of discovering the Inert Doublet Model scalars at CLIC. As signal processes, we consider the pair-production of inert scalars, namely e+e- -> H+H- and e+e- -> AH, followed by decays of charged scalars H+ and neutral scalars A into leptonic final states and missing transverse energy. We focus on signal signatures with two muons or an electron and a muon pair in the final state. A number of selected benchmark scenarios that cover the range of possible collider signatures of the IDM are considered. For the suppression of SM background with the same visible signature, multivariate analysis methods are employed. For several benchmark points discovery is already possible at low-energy stage of CLIC. Prospects of investigating scenarios that are only accessible at higher collider energies are also discussed.
hep-phhep-exJHEP(2019)·62 citations
11*
Gluequark Dark Matter
Roberto Contino🇮🇹 · Andrea Mitridate🇮🇹 · Alessandro Podo🇮🇹 · Michele Redi🇮🇹
We introduce the gluequark Dark Matter candidate, an accidentally stable bound state made of adjoint fermions and gluons from a new confining gauge force. Such scenario displays an unusual cosmological history where perturbative freeze-out is followed by a non-perturbative re-annihilation period with possible entropy injection. When the gluequark has electroweak quantum numbers, the critical density is obtained for masses as large as PeV. Independently of its mass, the size of the gluequark is determined by the confinement scale of the theory, leading at low energies to annihilation rates and elastic cross sections which are large for particle physics standards and potentially observable in indirect detection experiments.
hep-phJHEP(2019)·60 citations
12*
Soft drop groomed jet angularities at the LHC
Zhong-Bo Kang🇺🇸 · Kyle Lee🇺🇸 · Xiaohui Liu🇨🇳 · Felix Ringer🇺🇸
Jet angularities are a class of jet substructure observables where a continuous parameter is introduced in order to interpolate between different classic observables such as the jet mass and jet broadening. We consider jet angularities measured on an inclusive jet sample at the LHC where the soft drop grooming procedure is applied in order to remove soft contaminations from the jets. The soft drop algorithm allows for a precise comparison between theory and data and could be used to extract the QCD strong coupling constant $α_{s}$ from jet substructure data in the future. We develop a framework to realize the resummation of all relevant large logarithms at the next-to-leading logarithmic (NLL) accuracy. To demonstrate that the developed formalism is suitable for the extraction of $α_{s}$ , we extend our calculations to next-to-next-to-leading logarithm (NNLL) for the jet mass case. Overall, we find good agreement between our NLL numerical results and Pythia simulations for LHC kinematics and we observe an improved agreement when the NNLL components are included. In addition, we expect that groomed jet angularities will be a useful handle for studying the modification of jets in heavy-ion collisions.
hep-phhep-exnucl-exnucl-thPLB(2019)·80 citations
13*
Sivers Differential Cross Section for $π + X$ Production via $p^{↑} + p$ Collisions, and the Quark Sivers Function
Leonard S. Kisslinger🇺🇸 · Ming X. Liu🇺🇸 · Patrick McGaughey🇺🇸
We recently estimated pion+X production via proton collisions with a polarized proton target to enable the Collins fragmentation function to be determined via future experiments. In the present article we first estimate the Silvers differential cross section obtianed from experiments with the target proton having both positive and negative polarizations, and then estimate the Sivers Function using quark distribution functions.
hep-ph0 citations
14*
Physics Potentials of the Hyper-Kamiokande Second Detector in Korea
Seon-Hee Seo (for the Hyper-Kamiokande Proto-Collaboration)🇰🇷
Hyper-Kamiokande (Hyper-K) succeeds the very successful Super-K experiment and will consist of a large detector filled with 260~kton purified water and equipped with 40\% photo-coverage. Physics program of Hyper-K is broad, covering from particle physics to astrophysics and astronomy. The Hyper-K 1 $^{s t}$ detector will be built in Japan, and the 2 $^{n d}$ detector is considered to be built in Korea because locating the 2 $^{n d}$ detector in Korea improves physics sensitivities in most cases thanks to the longer baseline ( $\sim$ 1,100~km) and larger overburden ( $\sim$ 1,000~m) for Korean candidate sites. In this talk, we present overview and physics potentials of the Hyper-K 2 $^{n d}$ detector in Korea.
↳ hep-exhep-phphysics.ins-detPoS(2019)·6 citations
15*
Analysis of the duration--hardness ratio plane of gamma-ray bursts using skewed distributions
Mariusz Tarnopolski🇵🇱
The two widely accepted classes of gamma-ray bursts (GRBs), short and long, are with confidence ascribed to mergers of compact objects and collapse of massive stars, respectively. A third, intermediate/soft class, remains putative. Its existence was claimed based on univariate and bivariate analyses of GRB observables modeled with Gaussian distributions. This, however, may not be the appropriate approach, as it has been already shown that the univariate distributions of durations are better described by mixtures of two skewed components rather than three Gaussian ones. This paper investigates whether data in the duration--hardness ratio plane is better modeled by mixtures of skewed bivariate distributions than by normal ones. The archival data set of the Compton Gamma-Ray Observatory/BATSE and Fermi/GBM data from the most recent catalogue release are examined. The preferred model is chosen based on two information criteria, Akaike ( $A I C$ ) and Bayesian ( $B I C$ ). It is found that the best description is given by a two-component mixture of skewed Student- $t$ distributions, which outperforms any other model considered. This implies that the distribution of the studied parameters is intrinsically skewed, introducing spurious Gaussian components, and hence the third class is unlikely to be a real phenomenon. Its existence, based on statistical inference, is therefore rejected as unnecessary to explain the observations.
↳ astro-ph.HEastro-ph.IMhep-phApJ(2019)·33 citations
16*
Paleo-detectors: Searching for Dark Matter with Ancient Minerals
Andrzej K. Drukier🇸🇪 · Sebastian Baum🇸🇪 · Katherine Freese🇸🇪 · Maciej Górski🇵🇱 · Patrick Stengel🇸🇪
We explore paleo-detectors as an approach to the direct detection of Weakly Interacting Massive Particle (WIMP) dark matter radically different from conventional detectors. Instead of instrumenting a (large) target mass in a laboratory in order to observe WIMP-induced nuclear recoils in real time, the approach is to examine ancient minerals for traces of WIMP-nucleus interactions recorded over timescales as large as 1 Gyr. Here, we discuss the paleo-detector proposal in detail, including background sources and possible target materials. In order to suppress backgrounds induced by radioactive contaminants such as uranium, we propose to use minerals found in marine evaporites or in ultra-basic rocks. We estimate the sensitivity of paleo-detectors to spin-independent and spin-dependent WIMP-nucleus interactions. The sensitivity to low-mass WIMPs with masses $m_{χ} ≲ 10$ GeV extends to WIMP-nucleon cross sections many orders of magnitude smaller than current upper limits. For heavier WIMPs with masses $m_{χ} ≳ 30$ GeV cross sections a factor of a few to $\sim 100$ smaller than current upper limits can be probed by paleo-detectors.
↳ astro-ph.COastro-ph.IMhep-phphysics.ins-detPRD(2019)·64 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.