Produc'onof(an')nucleiinpp andPbPbcollisionswithALICE - - PowerPoint PPT Presentation

Produc'on
of
(an')nuclei
in
pp
 and
PbPb
collisions
with
ALICE
 at
the
LHC


Natasha
SHARMA
 (for
the
ALICE
Collabora'on)
 Panjab
University
 Chandigarh,
India.


1
 Natasha
Sharma


Outline


 Par'cle
iden'fica'on
technique
in
ALICE
  Raw
yields
and
spectra
for
(an')nuclei
  An'‐alpha
and
an'‐hypertriton
in
ALICE
  Summary
and
outlook


Natasha
Sharma
 2


Par'cle
iden'fica'on


3
 Natasha
Sharma


2.2
million
nuclear
collisions


Θ neg. particles

pp
(√s
=
7
TeV)
 PbPb
(√sNN
=
2.76
TeV)


Raw
yields
and
background
rejec'on


‐ Nuclei
can
also
be
 produced
due
to
 interac'on
with
material
 ‐ Compared
the
DCA
of
 nuclei
and
an'‐nuclei
to
 es'mate
the
background
 contribu'on
in
the
nuclei
 ‐ Final
counts
are
taken
as
 raw
yields



Natasha
Sharma
 4


d


_


d


PbPb
@
2.76
TeV


Raw
spectra:
an'‐d
&
an'‐3He


5
 Natasha
Sharma


pp
(√s
=
7
TeV)
 PbPb
(√sNN
=
2.76
TeV)


Only
sta's'cal
errors


An'‐alpha
and
nuclei‐ra'o


6
 Natasha
Sharma


An'‐alpha
iden'fica'on
:
 :
 Ra'os
of
an'‐nuclei
to
nuclei
:
  
Four
candidates
of
4He
are
found
in
the
PbPb
collisions
at
√sNN
=
2.76
TeV
(red
points).
 __


Natasha
Sharma
 7


An'‐hypertriton
reconstruc'on


mass


Summary
and
Outlook


 ALICE
is
an
excellent

detector
to
study
the
produc'on
of
nuclei
and
an'‐ nuclei

  We
have
extracted
d‐dbar,
t‐tbar,
3He‐an'3He
raw
spectra
in
pp
@
7
TeV
and
 PbPb
@
2.76
TeV
  An'‐alpha
and
an'‐hypertriton
signals
are
observed
with
the
present
 sta's'cs
in
PbPb
collisions


8
 Natasha
Sharma


• Comparison
of
spectra
in
pp
and
PbPb
collisions


(yields,
slopes,
radial
flow).


• Comparison
of
par'cle
ra'os
with
thermal
model


predic'ons
and
coalescence
expecta'ons.
 Outlook:
 Summary: