High pHigh pt t ππ00 correlations at correlations at ITEPITEP

Prokudin Mikhail, Prokudin Mikhail, ITEPITEP

OutlineOutline

►SetupSetup►Two possible scenariosTwo possible scenarios

Why it is interesting to study Why it is interesting to study ππ00 correlationscorrelations

►Cross section estimationsCross section estimations►Width of effect estimationWidth of effect estimation

SetupSetup

Target

EC

AL1

EC

AL2

~320Beam

Target: C12, Be9

Beam parameters:

Ions: He4, C12 Energy: 4.5 GeV/AIntensity: 1010 part/s

Two possible scenariosTwo possible scenarios

► Use Use ππ00 as a trigger as a trigger of cumulative of cumulative processprocess

►High multiplicity High multiplicity baryon system at baryon system at opposite directionopposite direction Not possible to study Not possible to study

with ECAL (DEMON?)with ECAL (DEMON?)

Two possible scenariosTwo possible scenarios

► Use Use ππ00 as a trigger of as a trigger of cumulative processcumulative process

► Low number of hi Low number of hi momentum mesons momentum mesons at opposite directionat opposite direction Second ECAL will Second ECAL will

perform well with perform well with ππ00 and and γγ

►ππ00 correlation can be correlation can be used for scenario used for scenario verification verification

Parameterization used:Parameterization used:

Cross section estimationsCross section estimations

45cos)45cos(cos1

075.0

3800),exp(

20

01

3

3

1

p

Cp

pC

dp

dE

For non correlated pions in cumulative For non correlated pions in cumulative regionregion

See Egor presentation for details

Cross section estimationCross section estimation

Parameterization used:Parameterization used:

)exp(

)exp(

22

11

t

t

ppc

ppc

For correlated pions in non cumulative For correlated pions in non cumulative regionregion

for pp collisionsfor pp collisions

Pair production of pions with symmetric momenta in the range 0.5<pt<2.0 GeV/c in 70 GeV p-p collisions. V.V. Abramov, B.Yu. Baldin and others. Physics Letters Vol. 112B, number 2

Cross section estimation.Cross section estimation.A-dependence.A-dependence.

► ppss=p=pt1t1+p+pt2t2

► αα>1 for p>1 for pss>2GeV for >2GeV for inclusive photonsinclusive photons rescattering??? rescattering???

► αα≈1 for p≈1 for pss>2GeV for >2GeV for correlated pionscorrelated pions no rescatteringno rescattering

- for inclusive pions

- 1450<φ<1800

For correlated pions in non For correlated pions in non cumulative region for p-nucleus cumulative region for p-nucleus

collisionscollisions

Azimuthal correlations of γ quanta produced in proton-Be and proton-Cu collisions at the energy of 70 GeV at the angle 900

in c.m.s. Abramov V.V. and others. Journal of nuclear physics vol. 24 number 5(11) 1982

αα

Width of effect estimationWidth of effect estimation

► For p-nucleus For p-nucleus collisionscollisions

►Width of effect Width of effect decreasing with pdecreasing with ptt

► R becomes large for R becomes large for ppss>2GeV>2GeV

No data for cumulative region No data for cumulative region foundfound

- p-Be - p-Cu

R

Azimuthal correlations of γ quanta produced in proton-Be and proton-Cu collisions at the energy of 70 GeV at the angle 900

in c.m.s. Abramov V.V. and others. Journal of nuclear physics vol. 24 number 5(11) 1982

ConclusionsConclusions

►Seems hard processes starts from Seems hard processes starts from pptt>2 GeV>2 GeV For our beam energy this means For our beam energy this means

cumulative regioncumulative region Strong correlations accompanying stiff Strong correlations accompanying stiff

processesprocesses

►Width of effect decreasing with pWidth of effect decreasing with ptt