高能物理-现象学学术速递[1.10]
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hep-ph高能物理-现象学，共计24篇
【1】 Dark sectors in neutron-shining-through-a-wall and nuclear absorption signals
标题：中子穿壁照射信号中的暗区和核吸收信号
链接：https://arxiv.org/abs/2201.02603
备注：12 pages, 2 figures
摘要：We propose new searches for $n^\prime$, a dark baryon that can mix with the
Standard Model neutron. We show that IsoDAR, a proposal to place an intense
cyclotron near a large-volume neutrino detector deep underground, can look for
$n\to n^\prime \to n$ transitions with much lower backgrounds than surface
experiments. This neutron-shining-through-a-wall search would be possible
without any modifications to the experiment and would provide the strongest
laboratory constraints on the $n$-$n^\prime$ mixing for a wide range of mass
splittings. We also consider dark neutrons as dark matter and show that their
nuclear absorption at deep-underground detectors such as SNO and Borexino
places some of the strongest limits in parameter space. Finally, we describe
other $n^\prime$ signatures, such as neutrons shining through walls at
spallation sources, reactors, and the disappearance of ultracold neutrons.
【2】 Evaluation of multi-loop multi-scale Feynman integrals for precision physics
标题：精细物理多回路多尺度Feynman积分的评价
链接：https://arxiv.org/abs/2201.02576
摘要：Modern particle physics is increasingly becoming a precision science that
relies on advanced theoretical predictions for the analysis and interpretation
of experimental results. The planned physics program at the LHC and future
colliders will require three-loop electroweak and mixed electroweak-QCD
corrections to single-particle production and decay processes and two-loop
electroweak corrections to pair production processes, all of which are beyond
the reach of existing analytical and numerical techniques in their current
form. This article presents a new semi-numerical approach based on differential
equations with boundary terms specified at Euclidean kinematic points. These
Euclidean boundary terms can be computed numerically with high accuracy using
sector decomposition or other numerical methods. They are then mapped to the
physical kinematic configuration with a series solution of the differential
equation system. The method is able to deliver 8 or more digits precision, and
it has a built-in mechanism for checking the accuracy of the obtained results.
Its efficacy is illustrated with examples for three-loop self-energy and vertex
integrals and two-loop box integrals.
【3】 On the definition of local spatial densities in hadrons
标题：关于强子局域空间密度的定义
链接：https://arxiv.org/abs/2201.02565
备注：5 pages, 1 figure
摘要：We show that the matrix element of a local operator between hadronic states
gives rise to an unambiguous definition of the associated spatial density. As
an explicit example, we consider the charge density of a spinless particle in
the rest and moving frames and clarify its relationship to the electric form
factor. Our results suggest that the interpretation of the spatial densities of
local operators and their moments such as the mean square charge radius needs
to be revised.
【4】 Rethinking the ill-posedness of the spectral function reconstruction -- why is it fundamentally hard and how Artificial Neural Networks can help
标题：关于谱函数重构不适定性的再思考--为什么从根本上说是困难的以及人工神经网络是如何提供帮助的
链接：https://arxiv.org/abs/2201.02564
备注：29 pages, 6 figures
摘要：Reconstructing hadron spectral functions through Euclidean correlation
functions are of the important missions in lattice QCD calculations. However,
in a K\"allen--Lehmann(KL) spectral representation, the reconstruction is
observed to be ill-posed in practice. It is usually ascribed to the fewer
observation points compared to the number of points in the spectral function.
In this paper, by solving the eigenvalue problem of continuous KL convolution,
we show analytically that the ill-posedness of the inversion is fundamental and
it exists even for continuous correlation functions. We discussed how to
introduce regulators to alleviate the predicament, in which include the
Artificial Neural Networks(ANNs) representations recently proposed by the
Authors in [arXiv:2111.14760]. The uniqueness of solutions using ANNs
representations is manifested analytically and validated numerically.
Reconstructed spectral functions using different regularization schemes are
also demonstrated, together with their eigen-mode decomposition. We observe
that components with large eigenvalues can be reliably reconstructed by all
methods, whereas those with low eigenvalues need to be constrained by
regulators.
【5】 Revisiting the gluino mass limits in the pMSSM in the light of the latest LHC data and Dark Matter constraints
标题：根据最新的LHC数据和暗物质约束重新讨论pMSSM中的胶子质量极限
链接：https://arxiv.org/abs/2201.02531
备注：37 pages LaTex, comments are welcome
摘要：The purpose of this paper is to examine the model dependence of the stringent
constraints on the gluino mass obtained from the Large Hadron Collider (LHC)
experiments by analyzing the Run II data using specific simplified models based
on several ad hoc sparticle spectra which cannot be realized even in the fairly
generic pMSSM models. We first revisit the bounds on the gluino mass placed by
the ATLAS collaboration using the $1l + jets + \met$ data. We show that the
exclusion region in the $M_{\widetilde{g}}-M_{\widetilde{\chi}^0_1}$ plane in
the pMSSM scenario sensitively depends on the mass hierarchy between the left
and right squarks and composition of the lighter electroweakinos and, to a
lesser extent, other parameters. Most importantly, for higgsino type lighter
electroweakinos (except for the LSP), the bound on the gluino mass from this
channel practically disappears. However, if such models are confronted by the
ATLAS $jets + \met$ data, fairly strong limits are regained. Thus in the pMSSM
an analysis involving a small number of channels may provide more reliable mass
limits. We have also performed detailed analyses on neutralino dark matter
(DM)constraints in the models we have studied and have found that for a
significant range of LSP masses, the relic density constraints from the
WMAP/PLANCK data are satisfied and LSP-gluino coannihilation plays an important
role in relic density production. We have also checked the simultaneous
compatibility of the models studied here with the direct DM detection, the
IceCube data, and the LHC constraints.
【6】 off-shell $t\bar{t}b\bar{b}$ in the di-lepton channel
标题：双轻子通道中的脱壳$tar{t}条{b}$
链接：https://arxiv.org/abs/2201.02519
备注：Talk at the 14th International Workshop on Top Quark Physics (videoconference), 13-17 September 2021
摘要：We report on our recent calculation for the off-shell $t\bar{t}b\bar{b}$
process in the di-lepton decay channel at the LHC. Our results take into
account NLO QCD corrections for the complete $pp\to e^+\nu_e\mu^- \bar{\nu}_\mu
b\bar{b}b\bar{b}$ process, and include all double, single and non-resonant
contributions. We investigate the size of the corrections and their associated
theoretical uncertainties. We also briefly comment on the impact of different
$b$ jet definitions on our results.
【7】 Polarized vector meson production at the Electron-Ion Collider
标题：在电子-离子对撞机上产生极化矢量介子
链接：https://arxiv.org/abs/2201.02511
备注：11 pages, 1 figure
摘要：We make a systematic calculation for polarized vector meson production in
semi-inclusive lepton-nucleon deep inelastic scattering $e^-N\to e^-VX$ at the
Electron-Ion Collider. We consider the neutral current electro-weak
interactions at high energies which give rise to parity-violating effects. We
present a general kinematic analysis for the process and show that the cross
section are expressed by 81 structure functions. We further give a parton model
calculation for the process and show the results for the structure functions in
terms of the transverse momentum dependent parton distribution functions and
fragmentation functions at the leading order and leading twist of perturbative
quantum chromodynamics. The result show that there are 27 non-zero structure
functions at this order, among which 15 are related to the tensor polarization
of the vector meson. 13 structure functions are generated by parity violating
effects. We also present the result for the spin alignment of the vector meson.
【8】 Lepton collider probes for Majorana neutrino effective interactions
标题：用于Majorana中微子有效相互作用的轻子对撞机探测器
链接：https://arxiv.org/abs/2201.02480
备注：23 pages, 10 figures, 3 tables
摘要：The extension of the standard model with new high-scale weakly coupled
physics involving right-handed neutrinos in an effective field theory framework
(SMNEFT) allows for a systematic study of heavy neutrinos phenomenology in
current and future experiments. We exploit the outstanding angular resolution
in future lepton colliders to study the sensitivity of forward-backward
asymmetries to discover the possible single production of heavy Majorana
neutrinos via $e^{+}e^{-} \to N \nu$, followed by a purely leptonic decay $N
\to \mu^{-} \mu^{+} \nu$ or a semi-leptonic decay $N \to \mu^{-} \mathrm{j}
\mathrm{j} $, for masses $m_N > 50$ GeV. In this regime, we consider the $N$
production and decays to be dominated by scalar and vectorial four-fermion
$d=6$ single $N_R$ operators. This is an alternative analysis to searches using
displaced vertices and fat jets, in a higher mass regime, where the $N$ is
short-lived but can be found by the angular distribution of its decay products.
We find that a forward-backward asymmetry between the final muons in the pure
leptonic decay mode provides a sensitivity up to 12$\sigma$ for $m_N=100$ GeV,
for effective couplings $\alpha=0.2$ and new physics scale $\Lambda=1$ TeV. In
the case of the semi-leptonic decay, we can compare the final muon and higher
$p_T$ jet flight directions, again finding up to 12$\sigma$ sensitivity to the
effective signals.
【9】 The one-loop impact of a dependent mass: the role of $m_3$ in the C2HDM
标题：依赖质量的单圈碰撞：$m_3$在C2HDM中的作用
链接：https://arxiv.org/abs/2201.02479
备注：22 pages
摘要：In the complex 2-Higgs-Doublet Model (C2HDM), the mass $m_3$ of the heaviest
neutral scalar $h_3$ is usually chosen as a derived parameter. We investigate
one-loop corrections to $m_3$ and their impact on decays of $h_3$. Strikingly,
very fine-tuned regions of the parameter space can be found where such
corrections are large, not due to subtraction schemes, but rather due to the
particular dependence of $m_3$ on the independent parameters. We show that even
moderate corrections can have a significant impact on decays of $h_3$, as they
may be several times enhanced by leading-order factors.
【10】 $m_b(m_Z)$ revisited with Zedometry
标题：$m_b(M_Z)$再论容量计量学
链接：https://arxiv.org/abs/2201.02417
备注：9 pages, 1 figure
摘要：Precision measurements of $Z^0$ boson properties could enable a determination
of the mass of the b quark at the scale of the $Z^0$ boson mass $m_b(m_Z)$. The
dependence of Standard Model predictions on the b quark mass using the program
Gfitter is studied. The precision of the currently available measurements by
the LEP experiments and SLD, together with measurements from the LHC
experiments of the mass of the top quark and the Higgs boson, is not sufficient
for a relevant measurement. The predicted precision of $Z^0$ boson resonance
measurements at future $e^+e^-$ colliders will allow a competitive
determination of $m_b(m_Z)$.
【11】 Anomalies in the differential cross sections at 13 TeV
标题：13TeV微分截面的反常现象
链接：https://arxiv.org/abs/2201.02403
备注：11 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:2009.10129, arXiv:1903.04976
摘要：Analysis of differential cross sections of the TOTEM Collaboration data,
carried out without model assumptions, shows the existence of new effects in
the behavior of the hadron scattering amplitude at a small momentum transfer at
a high confidence level. The quantitative description of the data in the
framework of the high energy generalized structure (HEGS) model supports such a
phenomenon that can be associated with the specific properties of the hadron
potential at large distances. It is shown that the value of $\rho(s,t)$ at
$\sqrt{s}=13$ TeV and small $t$ exceeded $0.1$.
【12】 Exploring neutrinos from proton decays catalyzed by GUT monopoles in the Sun
标题：从太阳肠单极子催化的质子衰变中探索中微子
链接：https://arxiv.org/abs/2201.02386
备注：13 pages, 5 figures, 2 tables
摘要：We explore the neutrino signals from proton decays catalyzed by GUT monopoles
in the Sun. Three typical proton decay modes, $p \rightarrow e^+ \pi$, $p
\rightarrow \mu^+ K^0$ and $p \rightarrow \bar{\nu}_e \pi^+$, have been
analyzed for the Super-Kamiokande experiment. The monopole-induced neutrinos
arise from interactions and subsequent decays of the proton decay products. To
obtain the neutrino energy spectra, we use the Geant4 software to simulate
propagations of daughter particles in the highly-dense solar center. It is
found that $K^0$ can produce a large amount of 236 MeV monoenergetic $\nu_\mu$
neutrinos through the charge exchange process $K^0 + p \rightarrow K^+ + n$ and
the subsequent decay $K^+ \rightarrow \mu^+ \nu_\mu$ at rest. Based on this
interesting feature, $p \rightarrow \mu^+ K^0$ can give the best discovery
potential among three decay modes for most of the parameter space. In addition,
we present the Super-Kamiokande sensitivities to the monopole flux for three
proton decay modes.
【13】 Direct $CP$ violation of three bodies decay process from the resonance effect
标题：共振效应对三体衰变过程的直接破坏
链接：https://arxiv.org/abs/2201.02385
摘要：The physical state of $\rho$-$\omega$-$\phi$ mesons can be mixed by the
unitary matrix. The decay processes of $\omega \rightarrow \pi^{+}\pi^{-}$ and
$\phi \rightarrow \pi^{+}\pi^{-}$ are from the isospin symmetry breaking. The
$\rho-\omega$, $\rho-\phi$ and $\omega-\phi$ interferences lead to resonance
contribution to produce the strong phases. The $CP$ asymmetry is considered
from above isospin symmetry breaking due to the new strong phase for the first
order. It has been found the $CP$ asymmetry can be enhanced greatly for the
decay process of $B^{0}\rightarrow\pi^+\pi^{-}\eta^{(')}$ when the invariant
masses of the $\pi^+\pi^{-}$ pairs are in the area around the $\omega$
resonance range and the $\phi$ resonance range in perturbative QCD.
【14】 On the exclusion limits in $t\bar{t}+$DM searches at the LHC
标题：关于大型强子对撞机$tar{t}+$Dm搜索的排除限度
链接：https://arxiv.org/abs/2201.02378
备注：4 pages, 1 figure, 1 table, YSF Talk at the 14th International Workshop on Top Quark Physics (videoconference), 13-17 September 2021
摘要：In these proceedings we discuss the importance of higher-order corrections
and off-shell effects for the calculation of signal strength exclusion limits
in $t\bar{t}+$DM searches at the Large Hadron Collider. We present limits for
the spin-0 s-channel mediator model using state-of-the-art NLO QCD predictions
with full off-shell effects for the relevant $t\bar{t}$ and $t\bar{t}Z$
background processes. These are then compared to less sophisticated predictions
using either the narrow-width approximation or LO calculations in order to
asses the respective effects.
【15】 Gravitational Reheating
标题：重力加热
链接：https://arxiv.org/abs/2201.02348
备注：5 pages, 4 figures
摘要：In this letter, we show for the first time that the perfect state of our
present universe can be obtained through gravitational interaction between
inflaton and all fundamental fields during reheating without invoking new
physics. Our analysis revealed that gravitational reheating is consistent for a
very restricted class of inflation models and narrow ranges of reheating
temperature and dark matter mass.
【16】 The mass spectrum and wave functions of the $B_c$ system
标题：$B_c$系统的质量谱和波函数
链接：https://arxiv.org/abs/2201.02318
备注：22 pages, 1 table
摘要：The spectrum and relativistic wave functions of $B_c$ system are investigated
via solving the complete Salpeter equation. Emphasis is placed on the study of
the partial wave content of each $J^P$ state, our study shows that there are 3
categories of $J^P$ states. The first category contains $0^-$ and $0^+$ states,
which are ${}^1S_0$ dominant state with a small amount of $P$ wave and
${}^3P_0$ dominant state with a small amount of $D$ wave, respectively. The
second category includes $1^-$, $2^+$ and $3^-$, etc, natural parity states;
take the $1^-$ state as an example, whose solution is further divided into two
cases, one is ${}^3S_1$ dominant state with small amount of $P$ and $D$ waves,
the other is ${}^3D_1$ dominant state but contains large amount of $S$ and $P$
wave components. The third category includes $1^+$, $2^-$ and $3^+$, etc,
unnatural parity states; take the $1^+$ state as an example, its solutions
appear in pairs, each pair is two ${}^1P_1-{}^3P_1$ mixing states, and the
corresponding mixing angle is calculated using the relativistic wave function.
【17】 Gravitational wave background from non-Abelian reheating after axion-like inflation
标题：类轴子膨胀后非阿贝尔再加热的引力波背景
链接：https://arxiv.org/abs/2201.02317
备注：18 pages
摘要：A pseudoscalar inflaton $\varphi$, coupled to the topological charge density
$F\tilde{F}$ of a non-Abelian sector, can decay to gauge bosons ($\varphi\to g
g $), which may thermalize rapidly. The friction felt by $\varphi$ is then
increased by non-Abelian "strong sphalerons", leading to a self-amplifying
process that can efficiently heat up the medium. We determine a lower bound for
the gravitational wave production rate from such a process, originating via
hydrodynamic fluctuations and particle collisions, in terms of a minimal number
of parameters. Only a moderate fraction of energy density is converted to
gravitational waves, suggesting that non-Abelian models may avoid the
overproduction observed in some Abelian cases.
【18】 Constraining dark matter-nucleon scattering cross section by the background electron anti-neutrino flux data
标题：用背景电子反中微子通量数据约束暗物质-核子散射截面
链接：https://arxiv.org/abs/2201.02315
备注：Accepted for publication in Physics Letters B
摘要：Celestial objects such as stars and planets might be able to capture a large
amount of dark matter particles through dark matter-nucleon scattering. Many
previous studies have considered different celestial objects such as the Sun
and the Earth as natural dark matter detectors and obtained some stringent
bounds of the dark matter-nucleon scattering cross section. In this study, we
use the $\sim 10$ MeV electron neutrino flux limits obtained by the
Super-Kamiokande experiment and consider the Earth as a large natural dark
matter detector to constrain the dark matter-nucleon scattering cross section.
We show that this method can generally get more stringent limits. For certain
ranges of dark matter mass annihilating via the $b\bar{b}$ channel, the limits
of cross section for the isospin-independent scattering and proton-only
scattering could be more stringent than that obtained in the PICO
direct-detection experiment.
【19】 Solving Combinatorial Problems at Particle Colliders Using Machine Learning
标题：用机器学习解决粒子对撞机中的组合问题
链接：https://arxiv.org/abs/2201.02205
备注：6 pages, 5 figures, submitted to PRL
摘要：High-multiplicity signatures at particle colliders can arise in Standard
Model processes and beyond. With such signatures, difficulties often arise from
the large dimensionality of the kinematic space. For final states containing a
single type of particle signature, this results in a combinatorial problem that
hides underlying kinematic information. We explore using a neural network that
includes a Lorentz Layer to extract high-dimensional correlations. We use the
case of squark decays in $R$-Parity-violating Supersymmetry as a benchmark,
comparing the performance to that of classical methods.
【20】 An Experiment for Electron-Hadron Scattering at the LHC
标题：大型强子对撞机上的电子-强子散射实验
链接：https://arxiv.org/abs/2201.02436
备注：27 pages, 24 figures, 6 tables; to appear in Eur. Phys. J. C
摘要：Novel considerations are presented on the physics, apparatus and accelerator
designs for a future, luminous, energy frontier electron-hadron ($eh$)
scattering experiment at the LHC in the thirties for which key physics topics
and their relation to the hadron-hadron HL-LHC physics programme are discussed.
Demands are derived set by these physics topics on the design of the LHeC
detector, a corresponding update of which is described. Optimisations on the
accelerator design, especially the interaction region (IR), are presented.
Initial accelerator considerations indicate that a common IR is possible to be
built which alternately could serve $eh$ and $hh$ collisions while other
experiments would stay on $hh$ in either condition. A forward-backward
symmetrised option of the LHeC detector is sketched which would permit
extending the LHeC physics programme to also include aspects of hadron-hadron
physics. The vision of a joint $eh$ and $hh$ physics experiment is shown to
open new prospects for solving fundamental problems of high energy heavy-ion
physics including the partonic structure of nuclei and the emergence of
hydrodynamics in quantum field theory while the genuine TeV scale DIS physics
is of unprecedented rank.
【21】 Chiral condensates and screening masses of neutral pseudoscalar mesons in thermomagnetic QCD medium
标题：热磁QCD介质中中性赝标介子的手征凝聚和屏蔽质量
链接：https://arxiv.org/abs/2201.02349
备注：11 pages, 9 figures
摘要：We point out that chiral condensates at nonzero temperature and magnetic
fields are in strict connection to the space-time integral of corresponding
two-point neutral meson correlation functions in the pseudoscalar channel via
the Ward-Takahashi identity. Screening masses of neutral pseudoscalar mesons,
which are defined as the exponential decay of the corresponding spatial
correlation functions in the long distance, thus are intrinsically connected to
(inverse) magnetic catalysis of chiral condensates. To study this we performed
lattice simulations of $(2+1)$-flavor QCD on $32^3\times N_t$ lattices with
pion mass $M_\pi\simeq 220$ MeV in a fixed scale approach having temperature
$T\in[17, 281]$ MeV and magnetic field strength $eB\in[0, 2.5]$ GeV$^2$. We
find that screening lengths, i.e. inverses of screening masses of $\pi^0$,
$K^0$ and $\eta^0_{s\bar{s}}$, turn out to have the similar complex $eB$ and
$T$ dependences of the corresponding chiral condensates. Although the
transition temperature is found to always decrease as $eB$ grows, we show that
the suppression due to magnetic fields becomes less significant for hadron
screening length and chiral condensates with heavier quarks involved, and
ceases to occur for $\eta^0_{s\bar{s}}$ and strange quark chiral condensate.
The complex $eB$ and $T$ dependences of both screening masses and chiral
condensates, reflecting the crossover nature of the QCD transition, are
attributed to the competition between sea and valence quark effects. These
findings could be useful to guide low-energy models and effective theories of
QCD.
【22】 Dynamical evolution of dark matter admixed neutron stars
标题：暗物质混合中子星的动力学演化
链接：https://arxiv.org/abs/2201.02274
备注：None
摘要：We dynamically evolve for the first time dark matter admixed neutron stars
with fermionic dark matter. These systems are mixtures of the ordinary nuclear
matter of a neutron star and dark matter. To perform our dynamical evolutions,
we derive the equations of motion, in conservation form, for spherically
symmetric systems with an arbitrary number of perfect fluids. Using finite
volume and high-resolution shock-capturing methods, we dynamically evolve the
two-fluid case, with the first fluid modeling ordinary matter and the second
fluid modeling dark matter. We use our dynamical solutions to study nonlinear
stability, radial oscillation frequencies, and a dynamical formation process.
【23】 Swiss-cheese cosmologies with variable $G$ and $Λ$ from the renormalization group
标题：重整化群中具有变量$G$和$Λ$的瑞士奶酪宇宙论
链接：https://arxiv.org/abs/2201.02251
备注：15 pages, 3 figures
摘要：A convincing explanation for the nature of the dark energy and dark matter is
still missing. In recent works a RG-improved swiss-cheese cosmology with an
evolving cosmological constant dependent on the \sch radius has been proven to
be a promising model to explain the observed cosmic acceleration. In this work
we extend this model to consider the combined scaling of the Newton constant
$G$ and the cosmological constant $\Lambda$ according to the IR-fixed point
hypothesis. We shall show that our model easily generates the observed recent
passage from deceleration to acceleration without need of extra energy scales,
exotic fields or fine tuning. In order to check the generality of the concept,
two different scaling relations have been analysed and we proved that both are
in very good agreement with $\Lambda$CDM cosmology. We also show that our model
satisfies the observational local constraints on $\dot{G}/G$.
【24】 Topological confinement in Skyrme holography
标题：Skyrme全息术中的拓扑约束
链接：https://arxiv.org/abs/2201.00105
备注：21 pages, 8 figures, new title, additional author
摘要：We study phase transitions in five-dimensional Einstein Gravity with a
negative cosmological constant, coupled to a Skyrme matter field. These
transitions are topological generalizations of the Hawking-Page transition
between thermal Anti de Sitter (AdS) spacetime and an AdS black hole. Phases
are characterized by a topological number associated with the Skyrme field
configuration. Depending on that topological number and on the Skyrme coupling
strength, there occur transitions between those phases at two, one, or no
value(s) of the temperature. Through the holographic (AdS/CFT) correspondence,
these solutions are dual to topologically non-trivial states in a conformal
field theory (CFT) with an SU(2)-symmetry, which support either confined or
deconfined (quasi-)particles at strong coupling. We compare to similar known
phase transitions, and discuss potential applications to confinement in
topological phases of condensed matter and the quark-gluon plasma.
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