Isolating the chiral magnetic effect from backgrounds by pair invariant mass

Abstract

Topological gluon configurations in quantum chromodynamics induce quark chirality imbalance in local domains, which can result in the chiral magnetic effect (CME)--an electric charge separation along a strong magnetic field. Experimental searches for the CME in relativistic heavy ion collisions via the charge-dependent azimuthal correlator ($\Delta \gamma$) suffer from large backgrounds arising from particle correlations (e.g. due to resonance decays) coupled with the elliptic anisotropy. We propose differential measurements of the $\Delta \gamma$ as a function of the pair invariant mass ($m_{\mathrm{inv}}$), by restricting to high $m_{\mathrm{inv}}$ thus relatively background free, and by studying the $m_{\mathrm{inv}}$ dependence to separate the possible CME signal from backgrounds. We demonstrate by model studies the feasibility and effectiveness of such measurements for the CME search.

16 preprint pages 5 figures. v2: added a test with a broad "instanton/sphaleron" peak, and added clarifying texts; v3: added event-shape engineering (and two new figures) and expanded discussions on the low invariant mass region; v4: repeated cautionary discussions in introduction and conclusion sections, published version

References in corpus (26)

• The Chiral Magnetic Effect
• Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR
• Charge separation induced by P-odd bubbles in QCD matter
• Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC
• Charge conservation in RHIC and contributiuons to local parity violation observables
• Observation of charge-dependent azimuthal correlations in pPb collisions and its implication for the search for the chiral magnetic effect
• Testing the Chiral Magnetic Effect with Central U+U collisions
• Anomalous Chiral Transport in Heavy Ion Collisions from Anomalous-Viscous Fluid Dynamics
• Azimuthal correlations from transverse momentum conservation and possible local parity violation
• Evolution of transverse flow and effective temperatures in the parton phase from a multi-phase transport model
• Test the chiral magnetic effect with isobaric collisions
• Importance of isobar density distributions on the chiral magnetic effect search
• On the Charge Separation Effect in Relativistic Heavy Ion Collisions
• A new method for the experimental study of topological effects in the quark-gluon plasma
• Charge Fluctuations from the Chiral Magnetic Effect in Nuclear Collisions
• Challenges in flow background removal in search for the chiral magnetic effect
• Separation of flow from chiral magnetic effect in U+U collisions using spectator asymmetry
• To CME or not to CME? Implications of p+Pb measurements of the chiral magnetic effect in heavy ion collisions
• Event-shape-engineering study of charge separation in heavy-ion collisions
• Origin of the mass splitting of azimuthal anisotropies in a multi-phase transport model
• Search for the Chiral Magnetic Effect in Relativistic Heavy-Ion Collisions
• Medium-modified Jets and Initial State Fluctuations as Sources of Charge Correlations Measured at RHIC
• Origin of the mass splitting of elliptic anisotropy in a multiphase transport model
• A novel invariant mass method to isolate resonance backgrounds from the chiral magnetic effect
• Chiral magnetic effect search in p(d)+Au, Au+Au collisions at RHIC
• Chiral magnetic effect search in p+Au, d+Au and Au+Au collisions at RHIC

Cited by in corpus (29)

• Mapping the Phases of Quantum Chromodynamics with Beam Energy Scan
• Anomalous chiral transports and spin polarization in heavy-ion collisions
• Chiral magnetic effect reveals the topology of gauge fields in heavy-ion collisions
• Experimental searches for the chiral magnetic effect in heavy-ion collisions
• Signatures of Chiral Magnetic Effect in the Collisions of Isobars
• Charge-dependent pair correlations relative to a third particle in $p$+Au and $d$+Au collisions at RHIC
• Implications of the isobar run results for chiral magnetic effect in heavy ion collisions
• Chiral Magnetic Effect in Heavy Ion Collisions: The Present and Future
• Probing the initial longitudinal density profile and electromagnetic field in ultrarelativistic heavy-ion collisions with heavy quarks
• Two- and three-particle nonflow contributions to the chiral magnetic effect measurement by spectator and participant planes in relativistic heavy ion collisions
• Revisit the Chiral Magnetic Effect Expectation in Isobaric Collisions at the Relativistic Heavy Ion Collider
• "Splitting" magnetic catalysis effect prevents vacuum superconductivity in strong magnetic fields
• Pair invariant mass to isolate background in the search for the chiral magnetic effect in Au+Au collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}$= 200 GeV
• Detecting Chiral Magnetic Effect via Deep Learning
• Effect of magnetic fields on pairs of oppositely charged particles in ultrarelativistic heavy-ion collisions
• HIJING can describe the anisotropy-scaled charge-dependent correlations at the Relativistic Heavy Ion Collider
• Complications in the interpretation of the charge asymmetry dependent $\pi$ flow for the chiral magnetic wave
• Importance of non-flow background on the chiral magnetic wave search
• The BEST framework for the search for the QCD critical point and the chiral magnetic effect
• A sensitivity study of the primary correlators used to characterize chiral-magnetically-driven charge separation
• Status of CME Search Before Isobar Collisions and Methods of Blind Analysis From STAR
• Decipher the $R_{{\Psi }_m}$ correlator in search for the chiral magnetic effect in relativistic heavy ion collisions
• Collective Excitation in High-Energy Nuclear Collisions -- In Memory of Professor Lianshou Liu
• Search for the chiral magnetic effect through beam energy dependence of charge separation using event shape selection
• Event-by-event correlations between $\Lambda$ ($\bar{\Lambda }$) hyperon global polarization and handedness with charged hadron azimuthal separation in Au+Au collisions at $\sqrt{s_{\text{NN}}}=27\text{ GeV}$ from STAR
• Experimental review on the chiral magnetic effect in relativistic heavy ion collisions
• The effect of electric and chiral magnetic conductivities on azimuthally fluctuating electromagnetic fields and observables in isobar collisions
• A new method to clarify contribution of chiral magnetic effect in small collision system $p^{\uparrow }+A$ involving a transversely polarized proton
• Electromagnetic anomaly in the presence of electric and chiral magnetic conductivities in relativistic heavy-ion collisions