Rauf MukhamedshinRauf Mukhamedshin Institute for Nuclear ResearchInstitute for Nuclear Research

Moscow RussiaMoscow Russia

On problems of choice of On problems of choice of hadron interaction modelshadron interaction models

and study of PCR spectrum and study of PCR spectrum

at ultra high energiesat ultra high energies

• Traditional ground-based EAS arrays detect lateral distributions of Traditional ground-based EAS arrays detect lateral distributions of

secondary particles (esecondary particles (e or or ))

• The higher EAS’ E0, the larger distance of operated detectors from The higher EAS’ E0, the larger distance of operated detectors from

the EAS axisthe EAS axis

• Lateral distributions depend on ELateral distributions depend on E00, <p, <ptt>, observation depth etc. >, observation depth etc.

• The larger is <pThe larger is <ptt>, the higher could be the estimated EAS energy>, the higher could be the estimated EAS energy

rr

(r)(r)

larger <plarger <ptt>>

lower <plower <ptt>>

QGSQGS models (QGSJETs, SYBILLs, HDPM, DPMJET, VENUS) models (QGSJETs, SYBILLs, HDPM, DPMJET, VENUS)

present the most popular conceptpresent the most popular concept

BUT!BUT!

Can these models describe all hadron interaction Can these models describe all hadron interaction

features at Efeatures at E00≳≳10101616 eV? eV?

NO!NO!

Phenomenon of Phenomenon of alignmentalignment (or (or coplanaritycoplanarity) of most ) of most

energetic cores in energetic cores in --hh families observed with families observed with

XRECs XRECs

is beyond QGSMis beyond QGSM

XRECsXRECs aboard aboard balloons and balloons and airplanesairplanes

XRECs of “PAMIR” experiment XRECs of “PAMIR” experiment

««CarbonCarbon» » C-XRECC-XREC ««LeadLead» » Pb-XRECPb-XREC

EEthrthr >> 4 TeV 4 TeV

procedure procedure –– mergingmerging of close of close

((ZZikik< < ZZCC) ) ii-th and -th and kk-th particles -th particles

for for reconstructionreconstruction of “initial” of “initial”-rays-rays: : Z ZСС ~ 1 TeV·cm ~ 1 TeV·cm

00-mesons-mesons: : Z ZСС ~ ~ 33 TeV·cm TeV·cm

hadronshadrons:: Z ZСС ~ ~ 2020 TeV·cm TeV·cmh*

X-r

ay f

ilm

s

pp ±±

ik=Rik (EiEk)1/2 ~ 2Zik

Energetically Distinguished Energetically Distinguished

CoresCores ((EDCEDC) ) == isolatedisolated clusters clusters

of particlesof particles ((,e,e,h,h)) joined with joined with

““decascadingdecascading””

--1/(1/(NN-1)-1) ≤≤ NN ≤≤ 1 1.0.0

Aligned eventAligned event:: NN ≥ ≥ fixfix

UsuallyUsually:: 44 ≥0≥0..88

Examples of Examples of aligned eventsaligned events

k

i

j

kij

Electromagnetic haloElectromagnetic halo hadron halohadron halohadronhadron -ray cluster -ray cluster

““Pamir”Pamir” : : a) a) Four- Four- -cluster event; -cluster event; b)b) Pb-6: Pb-6: 44=0.95;=0.95; c)c) Pb-28: Pb-28: 44=0.85. =0.85.

d)d) JF2af2JF2af2 event (“event (“Concorde”Concorde”); ); e)e) StranaStrana event (balloon). Digitals mean energy in TeV event (balloon). Digitals mean energy in TeV

-ray clusters

a) b)

c) d)

e) 5 most energetic particles

Pt = 23 7 GeV/c

(Preliminary !)

Fraction of aligned familiesFraction of aligned families

KanbalaKanbala datadata ((EE ≥ ≥ 5500 00 TeVTeV, , 33 ≥0 ≥0..8)8)

• 00..5500..22 in in Fe-Fe-XREC XREC ((33 from from 6, 6, 1.21.2 expected) expected)

EExpectedxpected background background:: 00.21.21Xue L. Xue L. et alet al.. 19991999

Only Only twotwo stratospheric stratospheric --hh families ( families (EE ≳≳ 1000 1000 TeVTeV)). . BothBoth are are

extremely alignedextremely aligned::

• 44 = = 00..999988 ( (JF2af2JF2af2,, ConcordeConcorde))

• 44 hh = = 00..9999 ((StranaStrana,, balloonballoon))

Strong interactionsStrong interactions ??

FluctuationsFluctuations ? ? Magnetic fieldMagnetic field ? ? Thunderstorm electricThunderstorm electric fieldfield ??

Regress.coeff. Regress.coeff. 3838==

00..999292

““PamirPamir” Experiment” Experiment ( (EE ≥≥ 700 700 TeVTeV, , 44 ≥0 ≥0..8)8)• 00..434300..1313 in in PbPb--XREC (XREC (66 from from 14 14, , 1.01.0 expected) expected) • 00..227700..0909 in in С- С- XREC XREC ((99 from from 35 35, , 2.12.1 expected) expected)

EExpectedxpected background background:: 00.06.06

• QGSM-type modelQGSM-type model

• describes “PAMIR” Collaboration’s data at <describes “PAMIR” Collaboration’s data at <EE00> > ≲≲ 55··101015 15 eV eV

(√s (√s ≲≲ 3 TeV3 TeV) and a lot of accelerator data) and a lot of accelerator data

• close toclose to QGSJET 98 QGSJET 98 ((CORSIKACORSIKA)) in features and simulation results in features and simulation results

Binomial distribution:Binomial distribution:Probability to observeProbability to observe kk aligned events in a set ofaligned events in a set of nn events: events:

= npq

Probability to observe the total set of experimentalProbability to observe the total set of experimental aligned events aligned events ((PamirPamir, , KanbalaKanbala, , stratospherestratosphere): ):

WWfluctfluct ~~ 0.90.9 1010-4-4 1.51.5 1010-4-4 99 1010-2-2 331010--33 66 1010-4-4 << 1010 ––114 4

It is an upper limit only !It is an upper limit only !

ExperimentExperiment CriterionCriterion

EExpected xpected aligned-event aligned-event

numbernumber (probability (probability for 1 for 1

eventevent))

Experi-Experi-mental mental event event

numbernumber

Expected Expected standard standard deviationdeviation

(())

DeviationDeviation from from

expectedexpected event event

numbernumber ((inin))

Probability Probability to observe to observe experim. experim.

data data

PamirPamir ( (PbPb)) 44≥0.≥0.88 11..00 from from 14 14 66 1.01.0 55 0.90.91010-4-4

Pamir Pamir (С)(С) 44≥0.≥0.88 22..11 from from 35 35 99 1.51.5 4,64,6 1.51.51010-4-4

KanbalaKanbala 33≥0.≥0.88 1.21.2 from from 6 6 33 1.21.2 1.51.5 9009001010-4-4

““Strana”Strana” 44≥0.99≥0.99 00.0029.00290.00.0000202 11 00..0505 -- 29291010-4-4

““JF2af2”JF2af2” 44≥0.998≥0.998 00..000000660.00.0000011 11 00..015015 -- 661010-4-4

Probability to observe the Probability to observe the total set oftotal set of experimentalexperimental aligned events aligned events

WWfluctfluct <<<< 1010--2020 ! !

Estimation of probability to observe Estimation of probability to observe in in “JF2af2”“JF2af2” the the regressionregression

3838 0 0..998 8 –– 0.99 0.99

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1 10 100N

w(

Nz

fix)

0.8

0.9

0.95

fix

-1-1

-2-2

-3-3

-4-4

-5-5

-6-6

-7-7

-8-8

-9-9

-10-10

-11-11

log

log

W(

W(

N

N ≥

≥ f

ixfix))

N=38N=38

coefficient coefficient 3838 = 0= 0..999292

WWfluctfluct((38 38 ≥ ≥ 0.95) 0.95) <<<< 10 10-9-9

38 38 ≥ ≥ 0.95 0.95 !!

Strong correlation Strong correlation between between NN and and N N !!

QGSMs CANNOT give such QGSMs CANNOT give such pp tt v values at alues at EE00 ~ 10 ~ 10 1616 eV ! eV !

Estimation of transverse momenta in the Estimation of transverse momenta in the “Strana”“Strana” eventevent

Geometry:Geometry:

PPt t = E = E x / Hx / H

p t= 237 GeV/c

Preliminary !

Indirect Indirect

methodsmethods

p t≃ 40–100 GeV/c

Very preliminary !

The alignment phenomenon The alignment phenomenon •is produced neither by is produced neither by fluctuationsfluctuations

nor by Earth’s nor by Earth’s magneticmagnetic or or thunderstorm thunderstorm electricelectric fields fields

•is caused by is caused by hadron interactionshadron interactions

Interpretation of alignmentInterpretation of alignment

• kinematic effects kinematic effects in diffraction processesin diffraction processes ( (SmorSmirSmorSmir 90, 90, Zhu 90, Zhu 90, Capd 01Capd 01););

““New” physicsNew” physics• new strong interaction new strong interaction at at √√ss ≳≳ 4 4 TeV; generation of bosons & TeV; generation of bosons &

hadrons with new higher-color hadrons with new higher-color superheavy quarkssuperheavy quarks (White 94) (White 94);;

High-QHigh-Qtt transfer models transfer models

• standard QCDstandard QCD

• gluon-jet gluon-jet generation (Halzen 90)generation (Halzen 90);;

• semihard double diffractive inelastic dissociation semihard double diffractive inelastic dissociation (SHDID) (Royzen(SHDID) (Royzen

9494); projectile’s ); projectile’s diquark breakingdiquark breaking (Capd 03) (Capd 03)

• QGS angular momentum conservation QGS angular momentum conservation (Wibig 04)(Wibig 04)

Specific correlation:Specific correlation: higherhigher pptt − − lowerlower ppLL

аа) QCD jets:) QCD jets: SinSin ii constconst inappropriate inappropriate correlationcorrelation ““Binocular”Binocular” familiesfamilies NONO alignment alignment (Lokhtin 05, e.g.)(Lokhtin 05, e.g.)

b)b) SHDIDSHDID (Royzen, 1994) – (Royzen, 1994) – rupture of stretched quark- rupture of stretched quark- gluon string (diffraction cluster) gluon string (diffraction cluster):: appropriateappropriate correlation correlation alignment can be observedalignment can be observed

cc) ) very-high-spinvery-high-spin leadingleading system system appropriateappropriate correlation correlation alignment can be observedalignment can be observed

dd) ) QGS angular momentumQGS angular momentum conservation conservation (Wibig 04)(Wibig 04) appropriateappropriate correlation correlation alignment can be observedalignment can be observed

most energetic particlesmost energetic particles

QCDQCD jetsjets:: Lokhtin Lokhtin et alet al 20200505PYTHIAPYTHIA @@ √s√s = = 114 4 TeVTeV ( (LHCLHC) ) ConclusionConclusion:: Alignment of Alignment of 33 ( (only only !) !) CLUSTERS (close to experimental one)CLUSTERS (close to experimental one)could be observed could be observed ONLYONLY at at

1.1. EE3,43,4jetjet ≥≥ 3 TeV 3 TeV, , ii..ee.. EE3,43,4

jetjet ~ E~ E11

ButBut:: EE3,43,4jetjet ~ E~ E11 ⋘⋘inelinel ! !

2.2. Distance fromDistance from interaction pointinteraction point toto observation levelobservation level ((target thicknesstarget thickness) ) x ~x ~00..

Alignment drops drastically Alignment drops drastically with increase of with increase of xx

ButBut:: a)a) in mountain experimentsin mountain experiments x > 500 g/cmx > 500 g/cm22

b)b) no alignment ofno alignment of particlesparticles and/or and/or NNclustercluster 44

QGS’ angular momentQGS’ angular moment (Wibig (Wibig 202004)04)

tt00 – – l l ~ ~ bb andand ~~ constconst ((bb≪≪b/2b/2

l l ~~const const andand ~~ 1/bb ((bb ~~b/2b/2(v (v = = c)c)

tt11 – – wave arrearswave arrears; ; ppt t distribution changesdistribution changes

PossiblePossible (?) (?) schemescheme

b/2

t1 t0

-b/2

conservation ofconservation of angular momentangular moment

CMSCMS LabLab

1) 1) interaction features are related to the fragmentation region onlyinteraction features are related to the fragmentation region only2)2) only a primitive only a primitive (!)(!) h heuristiceuristic tool to study factors related to the tool to study factors related to the

alignment observation alignment observation

CPGMCPGM == CCoplanar oplanar PParticle Generation article Generation MModelodel 1), 2)1), 2)

• particlesparticles ( ( && KK) ) are generated withare generated with • ‹‹pptt›› 0.4 GeV/c 0.4 GeV/c transversely totransversely to the coplanarity plane the coplanarity plane

• ‹‹ppTTcoplcopl›› 2. 2.33 GeV/c GeV/c in the coplanarity plane in the coplanarity plane

• multiplicitymultiplicity ‹‹nnss›› 1010

Etot > 500 TeV

0.01

0.1

1

0 200 400 600 800 1000XREC-to-interaction distance, g/cm2

F(

4z0.

8 )

ZC,TeV∙cm

background

F(F(44≥≥0.8) depends on0.8) depends on • depth in the atmospheredepth in the atmosphere• distance to interaction pointdistance to interaction point

If F(If F(44≥≥0.8) 0.8) 00..2 2

at at x x ≳≳ 500 500 gg//cmcm22

coplcopl~~inelinel

AlignmentAlignment can be only can be only studied in studied in

• high-resolution (high-resolution (x x ≲≲ 1cm ) 1cm ) mountain & stratosphericmountain & stratospheric(or collider) experiments(or collider) experiments

background

“Pamir” KASCADEEDCs

hadrons

p-airp-air

Dependence ofDependence of F(F(44zz0.8) on0.8) on ZZCC

0

0.1

0.2

0.3

0 2 4 6 8 10ZC, ТэВ∙см

F(

4z0

.8)

"Pamir"CPGMMC0

• F(F(44zz0.8)0.8) depends on depends on ZZCC

• CPGMCPGM explains the effectexplains the effect• ““Pamir’ & CPGM data have Pamir’ & CPGM data have

maxima at maxima at ZZCC 4 4 TeV·cmTeV·cm

• QGSMsQGSMs cannot explaincannot explain

Alignment dependence Alignment dependence onon

0

0.1

0.2

0.3

0.4

100 1000 10000E, TeV

F(

4 z0

.8)

Simulation:MC0 CPGM"Pamir" data:Nc>6,Ec>50 TeV

▲∆▲∆ Experimental F(Experimental F(44zz0.8)0.8) depends on depends on

□ □ CPGMCPGM can explaincan explain the the alignmentalignment

QGSMsQGSMs cannotcannot explain the alignment explain the alignment

CPG changes ER features ofCPG changes ER features of aligned aligned -h families-h families

““Pamir” (Borisov Pamir” (Borisov et alet al 2001) 2001) **

== 1.8 1.833 00..3737

== 2.5 2.577 ±± 00..8181

Ratios of Ratios of ‹‹ER›ER›44 & & ‹‹R›R›44 values in values in

aligned and unaligned aligned and unaligned - - familiesfamilies

0

1

2

100 1000 10000E,TeV

ER

"Pamir"

CPGM

MC0 CPGM (<PTcopl>=2.34 GeV/c)

CPGM (<PTCOPL>=2.34 GeV/c)

0

1

2

3

100 1000 10000E, TeV

R

"Pamir"

CPGM

MC0

‹‹ER›ER›4 4 aligned aligned >> ‹ER›‹ER›4 4 unalignedunaligned ‹R›‹R›4 4

aligned aligned >> ‹R› ‹R›4 4 unalignedunaligned;;

** NNcc ≥ 6, E≥ 6, Ecc ≥ 50 ≥ 50 ТэВТэВ

Why did anybody not observe earlier this process in Why did anybody not observe earlier this process in EAS and muon experiments?EAS and muon experiments?

These experiments are generally insensitive These experiments are generally insensitive to this effect.to this effect.

Influence of heavy primaries Influence of heavy primaries is much stronger is much stronger

Ratio of hadron densities Ratio of hadron densities (E(Ehh > 3 GeV) in EAS > 3 GeV) in EAS 3340 m a.s.l3340 m a.s.l

(Tien Shan)(Tien Shan)

PreliminaryPreliminary

CPG changes EAS properties in CPG changes EAS properties in a narrow lateral range (a narrow lateral range (≲≲1 m)1 m)

Difference Difference rangerange

ppCPGMCPGM / / pp

MC0MC0 FeFe

MC0MC0 / / ppMC0MC0

depends on model !depends on model !

AlignmentAlignment• can be only explained bycan be only explained by coplanar particle generationcoplanar particle generation

((<p<pTTcoplcopl> > >> 2 2 GeV/c) at GeV/c) at EE00 ≳≳ 10101166 eV (eV (√s √s ≳≳ 4 TeV) 4 TeV)

• cancan influence on lateral influence on lateral EASEAS featuresfeatures

Are PCR data derived from EAS data correct Are PCR data derived from EAS data correct

without taking these results into account?without taking these results into account?

Higher Higher pptt wider lateral distribution (normal longitudinal !)wider lateral distribution (normal longitudinal !)

could imitate (for classical EAS-array approach)could imitate (for classical EAS-array approach)• more heavy compositionmore heavy composition• higher EAS energyhigher EAS energy

Inconsistency of Inconsistency of results by results by fluorescence techniquesfluorescence techniques and and classical EAS-arrayclassical EAS-array approaches approaches

Due toDue to these these reasonsreasons ? ?

• collider experiments (collider experiments (LHCLHC) ) to studyto study

• high-resolution mountain experiments (high-resolution mountain experiments (Tien ShanTien Shan, , PamirsPamirs) ) interactionsinteractions

• development of theoretical models development of theoretical models • direct space experiments (direct space experiments (INCAINCA, , ACCESSACCESS (?)(?)) ) to study the “KNEE” to study the “KNEE”

range range to tune models to tune models

What can we do ?What can we do ?

Thank you !Thank you !

• High-energy High-energy muon groups are muon groups are insensitiveinsensitive to CPG process to CPG process

• Alignment of muon groups is mainly caused by Earth’s magnetic field Alignment of muon groups is mainly caused by Earth’s magnetic field

Multiplicity dependence of Multiplicity dependence of fraction of fraction of high-energyhigh-energy alignealigned d

muon groupsmuon groups

0,001

0,01

0,1

1

1 10 100N

F(

Nz

0,6)

Rmax = 100 m

MC0МКГЧRmax = 10 mMC0МКГЧ

RRmaxmax = 10 m = 10 m

RRmax max == 100 m100 m

EE 1 TeV 1 TeV

CPGM: <PCPGM: <Ptt>=2.3 GeV/c>=2.3 GeV/c

R.A.R.A. MukhamedshinMukhamedshin Institute for Nuclear Research Institute for Nuclear Research

Russian Academy of Sciences, Moscow, Russian Academy of Sciences, Moscow,

RussiaRussia

On concept of On concept of multipurpose astrophysicalmultipurpose astrophysical

orbital observatory orbital observatory for study of high-energyfor study of high-energy

primary cosmic raysprimary cosmic rays

Basic conceptBasic concept

1)1) leadlead2)2) polyethylenepolyethylene3)3) ScintillatorsScintillators4)4) HeliumHelium-2-2

neutron countersneutron counters5)5) SNMSNM-17 -17 neutronneutron

counterscounters6)6) electronicselectronics

boardsboards7)7) photodetectorsphotodetectors8)8) chargecharge detectorsdetectors

(5(5..5555..5 5 cmcm22

sectionssections))AA && BB – – sections of sections of

external partexternal partLtot – – totaltotal

dimensiondimension Lcal – – calorimetercalorimeter

dimensiondimension

12 3

4

5 67

8A

B

Lcal .

Ltot .

Basic conceptBasic concept

Basic features of two versions (Basic features of two versions (II & & IIII))

Basic conceptBasic concept

Basic features of two versions (Basic features of two versions (II && IIII) (continuation) ) (continuation)

Expected resultsExpected results

““KASCADE” and “Tibet” fits of the PCR spectrumKASCADE” and “Tibet” fits of the PCR spectrum

Expected resultsExpected results

Composition & spectraComposition & spectra

Expected resultsExpected results::• PCR nucleusPCR nucleus numbernumber (3-year(3-year exposure) exposure)

= S= S220 0 mm22sr: sr:

• N(EN(E00 10101515 eV) eV) ≳≳ 2 000 2 000

• N(EN(E00 10 101616 eV) eV) ≳≳ 30 30

• determination determination of of PCR components in the PCR components in the

“knee”“knee” rangerange

• choicechoice between between ““KASCADE”KASCADE” andand “TIBET” “TIBET”

spectraspectra QGSjet andQGSjet and SYBILL SYBILL

modelsmodels

Expected resultsExpected results

choice choice betweenbetween “KASCADE” “KASCADE” andand “TIBET” spectra“TIBET” spectra

Study of average mass numberStudy of average mass number

Expected resultsExpected results

choice choice betweenbetween “KASCADE” “KASCADE” andand “TIBET” spectra“TIBET” spectra

Study of protons-to-all particles ratioStudy of protons-to-all particles ratio

Expected resultsExpected results

Expected electron numberExpected electron number (3-year exposure &(3-year exposure & = S= S220 0 mm22sr): sr): • PCR electrons numberPCR electrons number N(EN(E00 >10 >101122 eV)eV) ~~ 2 2 101044

Study of electronsStudy of electrons

Expected resultsExpected results

Study of Study of -rays-rays

• sensitivity is sensitivity is comparablecomparable with ground-based arrays with ground-based arrays