arXiv subjects

H. Su

Publications and source records attributed to H. Su.

At least 37 records · Page 2Linked to original sources

arXiv2023

Simultaneous measurement of muon neutrino $ν_μ$ charged-current single $π^+$ production in CH, C, H$_2$O, Fe, and Pb targets in MINERvA

Neutrino-induced charged-current single $π^+$ production in the $Δ(1232)$ resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this work, high statistics differential cross sections are reported for the semi-exclusive reaction $ν_μA \to μ^- π^+ +$ nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wide-band $ν_μ$ beam with $\left< E_ν\right> \approx 6$~GeV. Suppression of the cross section at low $Q^2$ and enhancement of low $T_π$ are observed in both light and heavy nuclear targets compared to phenomenological models used in current neutrino interaction generators. The cross-section ratios for iron and lead compared to CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.

hep-ex↗

arXiv2023

Neutrino-induced coherent $π^{+}$ production in C, CH, Fe and Pb at $\langle E_ν\rangle \sim 6$ GeV

MINERvA has measured the $ν_μ$-induced coherent $π^{+}$ cross section simultaneously in hydrocarbon (CH), graphite (C), iron (Fe) and lead (Pb) targets using neutrinos from 2 to 20 GeV. The measurements exceed the predictions of the Rein-Sehgal and Berger-Sehgal PCAC based models at multi-GeV $ν_μ$ energies and at produced $π^{+}$ energies and angles, $E_π>1$ GeV and $θ_π<10^{\circ}$. Measurements of the cross-section ratios of Fe and Pb relative to CH reveal the effective $A$-scaling to increase from an approximate $A^{1/3}$ scaling at few GeV to an $A^{2/3}$ scaling for $E_ν>10$ GeV.

hep-ex↗

arXiv2023

High-Statistics Measurement of Antineutrino Quasielastic-like scattering at $E_ν\sim$ 6~GeV on a Hydrocarbon Target

We present measurements of the cross section for anti-neutrino charged-current quasielastic-like scattering on hydrocarbon using the medium energy (ME) NuMI wide-band neutrino beam peaking at $ \sim 6$ GeV. The cross section measurements are presented as a function of the longitudinal momentum ($p_{||}$) and transverse momentum ($p_{T}$) of the final state muon. This work complements our previously reported high statistics measurement in the neutrino channel and extends the previous anti-neutrino measurement made in the low energy (LE) beam at neutrino energy($ $) $\sim$ 3.5 GeV to $p_{T}$ of 2.5 GeV/c. Current theoretical models do not completely describe the data in this previously unexplored high $p_{T}$ region. The single differential cross section as a function of four momentum transfer ($Q^{2}_{QE}$) now extends to 4 GeV$^2$ with high statistics. The cross section as a function of $Q^{2}_{QE}$ shows that the tuned simulations developed by the MINERvA collaboration that agreed well with the low energy beam measurements do not agree as well with the medium energy beam measurements. Newer neutrino interaction models such as the GENIE 3 tunes are better able to simulate the high $Q^{2}_{QE}$.

hep-ex↗

arXiv2023

Simultaneous measurement of muon neutrino quasielastic-like cross sections on CH, C, water, Fe, and Pb as a function of muon kinematics at MINERvA

This paper presents the first simultaneous measurement of the quasielastic-like neutrino-nucleus cross sections on C, water, Fe, Pb and scintillator (hydrocarbon or CH) as a function of longitudinal and transverse muon momentum. The ratio of cross sections per nucleon between Pb and CH is always above unity and has a characteristic shape as a function of transverse muon momentum that evolves slowly as a function of longitudinal muon momentum. The ratio is constant versus longitudinal momentum within uncertainties above a longitudinal momentum of 4.5GeV/c. The cross section ratios to CH for C, water, and Fe remain roughly constant with increasing longitudinal momentum, and the ratios between water or C to CH do not have any significant deviation from unity. Both the overall cross section level and the shape for Pb and Fe as a function of transverse muon momentum are not reproduced by current neutrino event generators. These measurements provide a direct test of nuclear effects in quasielastic-like interactions, which are major contributors to long-baseline neutrino oscillation data samples.

hep-ex↗

arXiv2023

Magnetic properties of the layered heavy fermion antiferromagnet CePdGa$_6$

We report the magnetic properties of the layered heavy fermion antiferromagnet CePdGa$_{6}$, and their evolution upon tuning with the application of magnetic field and pressure. CePdGa$_{6}$ orders antiferromagnetically below $T\rm_{N}$ = 5.2 K, where there is evidence for heavy fermion behavior from an enhanced Sommerfeld coefficient. Our results are best explained by a magnetic ground state of ferromagnetically coupled layers of Ce $4f$-moments orientated along the $c$-axis, with antiferromagnetic coupling between layers. At low temperatures we observe two metamagnetic transitions for fields applied along the $c$-axis corresponding to spin-flip transitions, where the lower transition is to a different magnetic phase with a magnetization one-third of the saturated value. From our analysis of the magnetic susceptibility, we propose a CEF level scheme which accounts for the Ising anisotropy at low temperatures, and we find that the evolution of the magnetic ground state can be explained considering both antiferromagnetic exchange between nearest neighbor and next nearest neighbor layers, indicating the influence of long-range interactions. Meanwhile we find little change of $T\rm_{N}$ upon applying hydrostatic pressures up to 2.2 GPa, suggesting that significantly higher pressures are required to examine for possible quantum critical behaviors.

cond-mat.str-el↗

arXiv2023

Nodeless superconductivity in noncentrosymmetric LaRhSn

The superconducting order parameter of the noncentrosymmetric superconductor LaRhSn is investigated by means of low temperature measurements of the specific heat, muon-spin relaxation/rotation ($μ$SR) and the tunnel-diode oscillator (TDO) based method. The specific heat and magnetic penetration depth [$λ(T)$] show an exponentially activated temperature dependence, demonstrating fully gapped superconductivity in LaRhSn. The temperature dependence of $λ^{-2}(T)$ deduced from the TDO based method and $μ$SR show nearly identical behavior, which can be well described by a single-gap $s$-wave model, with a zero temperature gap value of $Δ(0)=1.77(4)k_BT_c$. The zero-field $μ$SR spectra do not show detectable changes upon cooling below $T_c$, and therefore there is no evidence for time-reversal-symmetry breaking in the superconducting state.

cond-mat.supr-con↗

arXiv2022

Neutron detection and application with a novel 3D-projection scintillator tracker in the future long-baseline neutrino oscillation experiments

Neutrino oscillation experiments require a precise measurement of the neutrino energy. However, the kinematic detection of the final-state neutron in the neutrino interaction is missing in current neutrino oscillation experiments. The missing neutron kinematic detection results in a feed-down of the detected neutrino energy compared to the true neutrino energy. A novel 3D\textcolor{black}{-}projection scintillator tracker, which consists of roughly ten million active cubes covered with an optical reflector, is capable of measuring the neutron kinetic energy and direction on an event-by-event basis using the time-of-flight technique thanks to the fast timing, fine granularity, and high light yield. The $\barν_μ$ interactions tend to produce neutrons in the final state. By inferring the neutron kinetic energy, the $\barν_μ$ energy can be reconstructed better, allowing a tighter incoming neutrino flux constraint. This paper shows the detector's ability to reconstruct neutron kinetic energy and the $\barν_μ$ flux constraint achieved by selecting the charged-current interactions without mesons or protons in the final state.

hep-ex↗

arXiv2022

Measurement of inclusive charged-current $ν_μ$ cross sections as a function of muon kinematics at $ \sim6~GeV$ on hydrocarbon

MINERvA presents a new analysis of inclusive charged-current neutrino interactions on a hydrocarbon target. We report single and double-differential cross sections in muon transverse and longitudinal momentum. These measurements are compared to neutrino interaction generator predictions from GENIE, NuWro, GiBUU, and NEUT. In addition, comparisons against models with different treatments of multi-nucleon correlations, nuclear effects, resonant pion production, and deep inelastic scattering are presented. The data recorded corresponds to $10.61\times10^{20}$ protons on target with a peak neutrino energy of approximately 6 GeV. The higher energy and larger statistics of these data extend the kinematic range for model testing beyond previous MINERvA inclusive charged-current measurements. The results are not well modeled by several generator predictions using a variety of input models.

hep-ex↗

arXiv2022

Data Preservation at MINERvA

Between 2013 and 2019 MINERvA collected an accelerator neutrino interaction dataset that is uniquely relevant to the energy range of DUNE. These are the only currently available data at intermediate and high momentum transfers for multiple nuclear targets in the same beam. MINERvA is undertaking a campaign to preserve these data and make them publicly available so that they may be analyzed beyond the end of the MINERvA collaboration. We encourage the community to consider the development of centralized resources to enable long-term access to these data and analysis tools for the entire HEP community.

hep-ex↗

arXiv2022

Improved constraint on the MINERvA medium energy neutrino flux using $\barνe^{-} \!\rightarrow \barνe^{-}$ data

Processes with precisely known cross sections, like neutrino electron elastic scattering ($νe^{-} \!\rightarrow νe^{-}$) and inverse muon decay ($ν_μe^{-} \!\rightarrow μ^{-} ν_e$) have been used by MINERvA to constrain the uncertainty on the NuMI neutrino beam flux. This work presents a new measurement of neutrino elastic scattering with electrons using the medium energy \numubar enhanced NuMI beam. A sample of 578 events after background subtraction is used in combination with the previous measurement on the \numu beam and the inverse muon decay measurement to reduce the uncertainty on the \numu flux in the \numu-enhanced beam from 7.6\% to 3.3\% and the \numubar flux in the \numubar-enhanced beam from 7.8\% to 4.7\%.

hep-ex↗

arXiv2022

Search for relativistic fractionally charged particles in space

More than a century after the performance of the oil drop experiment, the possible existence of fractionally charged particles FCP still remains unsettled. The search for FCPs is crucial for some extensions of the Standard Model in particle physics. Most of the previously conducted searches for FCPs in cosmic rays were based on experiments underground or at high altitudes. However, there have been few searches for FCPs in cosmic rays carried out in orbit other than AMS-01 flown by a space shuttle and BESS by a balloon at the top of the atmosphere. In this study, we conduct an FCP search in space based on on-orbit data obtained using the DArk Matter Particle Explorer (DAMPE) satellite over a period of five years. Unlike underground experiments, which require an FCP energy of the order of hundreds of GeV, our FCP search starts at only a few GeV. An upper limit of $6.2\times 10^{-10}~~\mathrm{cm^{-2}sr^{-1} s^{-1}}$ is obtained for the flux. Our results demonstrate that DAMPE exhibits higher sensitivity than experiments of similar types by three orders of magnitude that more stringently restricts the conditions for the existence of FCP in primary cosmic rays.

astro-ph.HE↗

arXiv2022

Semimetallic Kondo lattice behavior in YbPdAs with a distorted kagome structure

We have synthesized YbPdAs with the hexagonal ZrNiAl-type structure, in which the Yb-atoms form a distorted kagome sublattice in the hexagonal basal plane. Magnetic, transport, and thermodynamic measurements indicate that YbPdAs is a low-carrier Kondo lattice compound with an antiferromagnetic transition at $T_\mathrm{N}$ = 6.6 K, which is slightly suppressed in applied magnetic fields up to 9 T. The magnetic entropy at $T_\mathrm{N}$ recovers only 33\% of $R\ln{2}$, the full entropy of the ground state doublet of the Yb-ions. The resistivity displays a $-\ln T$ dependence between 30 and 15 K, followed by a broad maximum at $T\rm_{coh}$ = 12 K upon cooling. Below $T\rm_{coh}$, the magnetoresistance changes from negative to positive, suggesting a crossover from single-ion Kondo scattering processes at intermediate temperatures to coherent Kondo lattice behaviors at low temperatures. Both the Hall resistivity measurements and band structure calculations indicate a relatively low carrier concentration in YbPdAs. Our results suggest that YbPdAs could provide an opportunity for examining the interplay of Kondo physics and magnetic frustration in low carrier systems.

cond-mat.str-el↗

arXiv2022

Measurement of inclusive charged-current $ν_{\numu}$ scattering on hydrocarbon at { } 6 GeV with low three-momentum transfer

The \minerva experiment reports double-differential cross-section measurements for $ν_μ$-carbon interactions with three-momentum transfer $|\vec{q}| < 1.2$ GeV obtained with medium energy exposures in the NuMI beam. These measurements are performed as a function of the three-momentum transfer and an energy transfer estimator called the available energy defined as the energy that would be visible in the detector. The double differential cross sections are compared to the GENIE and NuWro predictions along with the modified version of GENIE which incorporates new models for better agreement with earlier measurements from MINERvA. In these measurements, the quasi-elastic, resonance, and multi-nucleon knockout processes appear at different kinematics in this two-dimensional space. The results can be used to improve models for neutrino interactions needed by neutrino oscillation experiments.

hep-ex↗

arXiv2022

Simultaneous measurement of proton and lepton kinematics in quasielastic-like $ν_μ$-hydrocarbon interactions from 2 to 20 GeV

Neutrino charged-current quasielastic-like scattering, a reaction category extensively used in neutrino oscillation measurements, probes nuclear effects that govern neutrino-nucleus interactions. This Letter reports the first measurement of the triple-differential cross section for $ν_μ$ quasielastic-like reactions using the hydrocarbon medium of the MINERvA detector exposed to a wide-band beam spanning 2 $\leq$ E$_ν\leq$ 20 GeV. The measurement maps the correlations among transverse and longitudinal muon momenta and summed proton kinetic energies, and compares them to predictions from a state-of-art simulation. Discrepancies are observed that likely reflect shortfalls with modeling of pion and nucleon intranuclear scattering and/or spectator nucleon ejection from struck nuclei. The separate determination of leptonic and hadronic variables can inform experimental approaches to neutrino-energy estimation.

hep-ex↗

arXiv2022

Use of Neutrino Scattering Events with Low Hadronic Recoil to Inform Neutrino Flux and Detector Energy Scale

Charged-current neutrino interactions with low hadronic recoil ("low-nu") have a cross-section that is approximately constant versus neutrino energy. These interactions have been used to measure the shape of neutrino fluxes as a function of neutrino energy at accelerator-based neutrino experiments such as CCFR, NuTeV, MINOS and MINERvA. In this paper, we demonstrate that low-nu events can be used to measure parameters of neutrino flux and detector models and that utilization of event distributions over the upstream detector face can discriminate among parameters that affect the neutrino flux model. From fitting a large sample of low-nu events obtained by exposing MINERvA to the NuMI medium-energy beam, we find that the best-fit flux parameters are within their a priori uncertainties, but the energy scale of muons reconstructed in the MINOS detector is shifted by 3.6% (or 1.8 times the a priori uncertainty on that parameter). These fit results are now used in all MINERvA cross-section measurements, and this technique can be applied by other experiments operating at MINERvA energies, such as DUNE.

hep-ex↗

arXiv2022

Neutral pion reconstruction using machine learning in the MINERvA experiment at $\langle E_ν\rangle \sim 6$ GeV

This paper presents a novel neutral-pion reconstruction that takes advantage of the machine learning technique of semantic segmentation using MINERvA data collected between 2013-2017, with an average neutrino energy of $6$ GeV. Semantic segmentation improves the purity of neutral pion reconstruction from two gammas from 71\% to 89\% and improves the efficiency of the reconstruction by approximately 40\%. We demonstrate our method in a charged current neutral pion production analysis where a single neutral pion is reconstructed. This technique is applicable to modern tracking calorimeters, such as the new generation of liquid-argon time projection chambers, exposed to neutrino beams with $\langle E_ν\rangle$ between 1-10 GeV. In such experiments it can facilitate the identification of ionization hits which are associated with electromagnetic showers, thereby enabling improved reconstruction of charged-current $ν_e$ events arising from $ν_μ \rightarrow ν_{e}$ appearance.

hep-ex↗

arXiv2022

Evidence of fully-gapped superconductivity in NbReSi: A combined $μ$SR and NMR study

We report a comprehensive study of the noncentrosymmetric NbReSi superconductor by means of muon-spin rotation and relaxation ($μ$SR) and nuclear magnetic resonance (NMR) techniques. NbReSi is a bulk superconductor with $T_c = 6.5$ K, characterized by a large upper critical field, which exceeds the Pauli limit. Both the superfluid density $ρ_\mathrm{sc}(T)$ (determined via transverse-field $μ$SR) and the spin-lattice relaxation rate $T_1^{-1}(T)$ (determined via NMR) suggest a nodeless superconductivity (SC) in NbReSi. We also find signatures of multigap SC, here evidenced by the field-dependent muon-spin relaxation rate and the electronic specific-heat coefficient. The absence of spontaneous magnetic fields below $T_c$, as evinced from zero-field $μ$SR measurements, indicates a preserved time-reversal symmetry in the superconducting state of NbReSi. Finally, we discuss possible reasons for the unusually large upper critical field of NbReSi, most likely arising from its anisotropic crystal structure.

cond-mat.supr-con↗

arXiv2022

Suppression of ferromagnetism and influence of disorder in silicon-substituted CeRh6Ge4

We report a study of isoelectronic chemical substitution in the recently discovered quantum critical ferromagnet CeRh$_6$Ge$_4$. Upon silicon-doping, the ferromagnetic ordering temperature of CeRh$_6$(Ge$_{1-x}$Si$_x$)$_4$ is continuously suppressed, and no transition is observed beyond $x_c$$\approx$0.125. Non-Fermi liquid behavior with $C/T \propto$log($T^*/T$) is observed close to $x_c$, indicating the existence of strong quantum fluctuations, while the $T$-linear behavior observed upon pressurizing the parent compound is absent in the resistivity, which appears to be a consequence of the disorder induced by silicon doping. Our findings provide evidence for the role played by disorder on the unusual ferromagnetic quantum criticality in CeRh$_6$Ge$_4$, and provides further evidence for understanding the origin of this behavior.

cond-mat.str-el↗