production cross sections for anti-p and anti-d with ... · production cross sections for anti-p...
TRANSCRIPT
Productioncrosssectionsforanti-pandanti-d
withCOMPASS++/AMBER
P.ZucconTrentoUniversityandINFNTIFPA
M.Chiosso,O.DenisovTorinoUniversityandINFNTorino
N.MasiINFNBologna
2nd Cosmic-rayAntideuteron WorkshopUniversityofCalifornia– LosAngeles
Weleftheretwodaysago!
P.Zuccon- TrentoUniversity dbar19- UCLA 2
AMSMeasurementofanti-p/pratio
Twomajoruncertaintieslimitthepredictionoftheanti-pfluxfromCRinteractionwithISM• productioncrosssectionsp-p->pbar +Xp-He->pbar +X• CRpropagationinthegalaxy
Introduction
P.Zuccon- TrentoUniversity dbar19- UCLA 3
Fractionoriginofanti-pfromCRinteractionwithISM
Mar
tin W
. Win
kler
(Sto
ckho
lm
Uni
vers
ity)
LHCb-CONF-2017-002 Measurementperformedat7TeVp-He->pbar +X
NA61p+p data beammomentaof20,31,40,80,and158GeV/cEur.Phys.J.C77,671(2017)
• anti-pproductioncrosssectionfromp-pandp-Heinteractionsispoorlymeasuredandcannotsimplyconstrainedfromavailablemeasurements.
• anaccuratepredictionoftheexpectedanti-pfluxincosmicraysintherigidityrangefromfewGeVtoseveralhundredsofGeVs,isinterestingtounderstandcosmicrayandpossiblysearchforsignalsofnewphysics
• LHC-bcollaborationreportedameasurementtheanti-pXSfrom8TeV p-He,andforeseeasimilarmeasurementwith4TeVprotons.
• NA61publishedp-ptoanti-pat20,31,40,80,and158GeV/c
• wewanttoinvestigatethepossibilitytoperformameasurementwiththeSPSprotonsbetween50and280GeV/confixedLH2andLHe targets,andamagneticspectrometer
COMPASS@CERN
P.Zuccon- TrentoUniversity dbar19- UCLA 4
Acceptance:+/- 180mrad+/- 10deg2.4 < h < 8
FistStep
P.Zuccon- TrentoUniversity dbar19- UCLA 5
UseFLUKAtosimulatep-pandp-Heinteractionswithabeamof190GeV/c
momentum.
p-LH2eventfeatures@190GeV/c
P.Zuccon- TrentoUniversity dbar19- UCLA 6
3.05105 interactingevents
allZ!=0
anti-p#anti-p
Mean0.72
p-LHe eventfeatures@190GeV/c
P.Zuccon- TrentoUniversity dbar19- UCLA 7
2.25105 interactingevents
allZ!=0
anti-p#anti-p
Mean0.77
Secondstep
P.Zuccon- TrentoUniversity dbar19- UCLA 8
• UseFLUKAgeneratedinteractionasinputfortheofficialCOMPASSGeant 4simulation(TGEANT)
• PasstheproducedfilesthroughtheofficialCOMPASSreconstructionsoftware
COMPASSsimulation(p-p190GeV)
P.Zuccon- TrentoUniversity dbar19- UCLA 9
MC DATA
Numberoftracks(q <10deg)
VertexpositionVertexresolution
COMPASSRecaccuracy
P.Zuccon- TrentoUniversity dbar19- UCLA 10
COMPASSsimulation(p-p190GeV)
P.Zuccon- TrentoUniversity dbar19- UCLA 11
Antiprotontrackingefficiency
GeV)10
Momentum (log1− 0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4
)ηPs
eudo
repi
dity
(
11.5
22.5
33.5
44.5
55.5
66.5
77.5
88.5
99.510
10.511
11.5
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
RICHAcc
Pseudo-rapidityvslog10(momentum)
Thirdstep
P.Zuccon- TrentoUniversity dbar19- UCLA 12
EstimateRICHparticleidentificationperformancefromp-pdataalreadycollectedat190GeV
Selectpuresamplesofp,pbar,p+andp-
P.Zuccon- TrentoUniversity dbar19- UCLA 13
SelectasampleofV0• twotracksformingavertex• p=p1+p2pointstotheprimaryvertex
Armenteros plot
alpha=pl1-pl2/(pl1+pl2)
K0
L0anti-L0Aftercleanup(mindist,primang)
gamma
DATASETcollectedin2009(p-LH2)
Massselection
P.Zuccon- TrentoUniversity dbar19- UCLA 14
LambdaMass
Kaonmass
Massselection
P.Zuccon- TrentoUniversity dbar19- UCLA 15
LambdaMass
Kaonmass
SelectedTracksfromK0 andL0
P.Zuccon- TrentoUniversity dbar19- UCLA 16
Individual“pure”samples
P.Zuccon- TrentoUniversity dbar19- UCLA 17
pi- pi+
ppbar
RICHanglevsbg
P.Zuccon- TrentoUniversity dbar19- UCLA 18
pi- pi+
ppbar
GaussianFitoftheRICHangle
P.Zuccon- TrentoUniversity dbar19- UCLA 19
pi+pi-
pi+pi-
pi+pi-p
pi+pi-p
MPV MPV
sigmasigma
mrad
mrad
UniversalRICHresponsefunction
P.Zuccon- TrentoUniversity dbar19- UCLA 20
betaRICH
bg (tracking)
anti-pandpareidentifiedabovethreshold(~18GeV/c)withanefficiency>95%upto~60(GeV/c)FromtheKaonthreshold(~9GeV/c)tothepthreshold,pandanti-pareidentifiedusingRICHinvetomode.
anti-pspectrum@190GeV/c
Fourthstep
P.Zuccon- TrentoUniversity dbar19- UCLA 21
Combinetheelementstoobtainacrosssectionmeasurement
Crosssectionmeasurement
• Strategy• Countallthep-p(orp-He)interactioninthetarget(𝑅")• Identifyeventswithone(ormultiple)anti-pvsreconstructedmomentumandangle(𝑅#(𝑝, 𝜃))
• Calculatethedoubledifferentialcrosssectionas
𝑑𝜎,-𝑑𝑝𝑑𝜃 =
𝑅# 𝑝, 𝜃𝑅"
• Severalpossiblepitfallsandsourcesofsystematicerrors!
P.Zuccon- TrentoUniversity dbar19- UCLA 22
CompassTriggersystem
P.Zuccon- TrentoUniversity dbar19- UCLA 23
Ratestatisticsandpileup• Typicalbeamintensityis5107 pfora9.8sspill
• Weexpect~5.4%oftheprotonstointeractwiththe40cmLH2targetà ~270k interaction/s
• CompassstandardtriggerDT0is𝐵𝑇&𝐵𝐾&𝑆𝑎𝑛𝑑𝑤𝑖𝑐ℎ𝑉𝑒𝑡𝑜&𝑅𝑃𝐷
• Thisreducethetriggerrateto33kHzwhichcanbehandledbytheCOMPASSDAQ
• Forthefuturemeasurementswewillasktoreducethebeamintensityto5106 andplantousethetrigger
𝐵𝑇&𝐵𝐾&𝑆𝑎𝑛𝑑𝑤𝑖𝑐ℎ𝑉𝑒𝑡𝑜• Thiswillprovideanexpectedrateof25kHz
Upstream Threshold Cherenkov counter
BeamandTriggererror~0.5%
P.Zuccon- TrentoUniversity dbar19- UCLA 24
LostInteractionevents• Selectafiducialvolumeonthetarget[-68,-30]cm• Lookhowmanyeventshaveareconstructedvertexwithinthefiducialvolume
MCevents:288312NoVertex:2753(0.95%)Vtx outside:2856(0.99%)
ThankstotheRecoilDetectorno-vertexeventscanbecross-
checkedwithdata
Vertex error 0.5%
P.Zuccon- TrentoUniversity dbar19- UCLA 25
Summaryoftheexpectederrors
P.Zuccon- TrentoUniversity dbar19- UCLA 26
efficiency est syserror
TrackRecon 95% ~1%
Rich Efficiency ~99% ~0.5%
RICH PID 99 to75% 0.1to4%
Trigger 1%
Vertex error 98% 0.5%
BeamPurity 99.9% 0.5%
TOTAL 4to6%
Considering2targets(LHe andLH2,each50cmlong),TheestimatedacceptanceandefficiencyfromthefullCOMPASSMC.20binsinmomentumfrom[10,50]GeV/cand20bininPt75%beampurityat5E5p/sbeamintensityWeexpecttoreach1.7(1.0)%statistical errorinmostofthe400differentialcrosssectionbinswith4(12)hoursofbeamtimeforeachenergypoint.
Systematic
Towardanactualmeasurement
P.Zuccon- TrentoUniversity dbar19- UCLA 27
Theprogramformeasuringp-pandp-He->pbar (anddbar)+XhasbeenincludedintheCOMPASS2020LoI presentedtoCERN
ThenewprogramhasbeennamedCOMPASS++_AMBER.
TheprogramwouldstartaftertheLHClongshutdownin2021.Preliminarymeasurementsareexpectedtobeperformedin2021and2022.
TheLoI receivedapositiveevaluationandthecollaborationhasbeenrequestedtoprepareaproposalwithinthesummer
ProjectstoconvertaspareLH2targettoLHe willalsostartsoverthesummer.
Summary
• CRantimatterdatasensitivitytoexoticsourcesisdegradedbythepoorknowledgeofthepbar (anddbar)productioncrosssections
• Wehaveshownthatameasurementofp-p->pbar +Xandp-He->pbar +X(anddbar),canbeperformedatCERNwiththeCOMPASS++/AMBERspectrometeratmomentarangingfrom50GeV/cto280GeV/c
• Aletterofintentthatincludesaprogramforthesemeasurementshasbeensubmittedandreceivedapositiveevaluation
• Afullproposalisbeingnowworked
• Firstdatatakingissupposedtohappenin2021
P.Zuccon- TrentoUniversity dbar19- UCLA 28
P.Zuccon- TrentoUniversity dbar19- UCLA 29
Particlerangeat50GeV/cmomentum
P.Zuccon- TrentoUniversity dbar19- UCLA 30
MC_PID Name range Mass Charge Lifetime Energy Beta gammam GeV/c2 s GeV
20SIGMA0 9.31E-10 1.19E+00 0 7.40E-20 5.00E+01 1.00E+00 4228ANTISIGMA0 9.31E-10 1.19E+00 0 7.40E-20 5.00E+01 1.00E+00 4217ETA 1.50E-08 5.48E-01 0 5.49E-19 5.00E+01 1.00E+00 917PION0 9.33E-06 1.35E-01 0 8.40E-17 5.00E+01 1.00E+00 37024OMEGA- 7.38E-01 1.67E+00 -1 8.22E-11 5.00E+01 9.99E-01 3032ANTIOMEGA+ 7.38E-01 1.67E+00 1 8.22E-11 5.00E+01 9.99E-01 3027ANTISIGMA- 1.01E+00 1.19E+00 -1 7.99E-11 5.00E+01 1.00E+00 4219SIGMA+ 1.01E+00 1.19E+00 1 7.99E-11 5.00E+01 1.00E+00 4221SIGMA- 1.85E+00 1.20E+00 -1 1.48E-10 5.00E+01 1.00E+00 4229ANTISIGMA+ 1.85E+00 1.20E+00 1 1.48E-10 5.00E+01 1.00E+00 4223XI- 1.86E+00 1.32E+00 -1 1.64E-10 5.00E+01 1.00E+00 3831ANTIXI+ 1.86E+00 1.32E+00 1 1.64E-10 5.00E+01 1.00E+00 3816KAON0SHORT 2.69E+00 4.98E-01 0 8.93E-11 5.00E+01 1.00E+00 10022XI0 3.31E+00 1.32E+00 0 2.90E-10 5.00E+01 1.00E+00 3830ANTIXI0 3.31E+00 1.32E+00 0 2.90E-10 5.00E+01 1.00E+00 3818LAMBDA 3.54E+00 1.12E+00 0 2.63E-10 5.00E+01 1.00E+00 4526ANTILAMBDA 3.54E+00 1.12E+00 0 2.63E-10 5.00E+01 1.00E+00 4512KAON- 3.76E+02 4.94E-01 -1 1.24E-08 5.00E+01 1.00E+00 10111KAON+ 3.76E+02 4.94E-01 1 1.24E-08 5.00E+01 1.00E+00 10110KAON0LONG 1.56E+03 4.98E-01 0 5.17E-08 5.00E+01 1.00E+00 1009PION- 2.80E+03 1.40E-01 -1 2.60E-08 5.00E+01 1.00E+00 3588PION+ 2.80E+03 1.40E-01 1 2.60E-08 5.00E+01 1.00E+00 3586MUON- 3.12E+05 1.06E-01 -1 2.20E-06 5.00E+01 1.00E+00 4735MUON+ 3.12E+05 1.06E-01 1 2.20E-06 5.00E+01 1.00E+00 47313NEUTRON 1.42E+13 9.40E-01 0 8.87E+02 5.00E+01 1.00E+00 5325ANTINEUTRON 1.42E+13 9.40E-01 0 8.87E+02 5.00E+01 1.00E+00 5346TRITON 5.35E+24 2.81E+00 1 1.00E+15 5.01E+01 9.98E-01 1845DEUTERON 8.00E+24 1.88E+00 1 1.00E+15 5.00E+01 9.99E-01 2715ANTIPROTON 1.60E+25 9.38E-01 -1 1.00E+15 5.00E+01 1.00E+00 5314PROTON 1.60E+25 9.38E-01 1 1.00E+15 5.00E+01 1.00E+00 533ELECTRON 2.94E+28 5.11E-04 -1 1.00E+15 5.00E+01 1.00E+00 978472POSITRON 2.94E+28 5.11E-04 1 1.00E+15 5.00E+01 1.00E+00 9784749HE3 5.35E+24 2.81E+00 2 1.00E+15 5.01E+01 9.98E-01 1847ALPHA 4.04E+24 3.73E+00 2 1.00E+15 5.01E+01 9.97E-01 13