Peach trees are subject to serious insect pests and diseases.
Frequently, the season’s crop may be lost either by flower bud kill due to low winter temperatures or to bloom kill by late-spring frosts.  Try to protect the blooms from late-spring frosts Mulch a six foot diameter area under the tree canopy with 3 inches of wood chip or bark. Keep the mulch 3 Inches away from the trunk.  Try to maintain the health of your peach tree. Healthy trees live longer and are less susceptible to insects and fungus problems. During times of little rain or drought, provide irrigation for peach trees.  Take care when mowing or weeding around the trees to not cause wounds or deep nicks in the base of the trunk that might allow other pests to infest the tree.  Pruning should be delayed as much as possible but before it blossoms. This promotes quick healing. Remove cankered branches and dead wood while pruning.  This season prune off  the dead branch as soon as possible. Dispose or burn the dead wood and cankers on the small limbs that are removed. Avoid excessive late nitrogen fertilization, so that tree does not delay dormancy and suffer from cold winter injury.  Water sprouts on the inside of the trees are often thin and weak, and can be readily colonized by fungus to gain entry into the supporting limb.  Remove water sprouts before winter begins. White latex paint applied to the southwest side of trunks and lower scaffold branches may help the tree to avoid cold injury.
     Cytospora is a destructive disease of peach trees that
produces bark cankers that gradually enlarge and eventually girdle and kill limbs and trees. Amber-colored gum (gummosis) often exudes through the bark around these cankers.
There are no effective fungicides for cytospora cankers, so control has to be managed culturally.

The following sites explain how to cut out  cankers. https://ohioline.osu.edu/factsheet/plpath-fru-25
http://plantclinic.cornell.edu/factsheets/cytosporacankerfruit.pdf

Good luck with your peach tree. Prune off the dead branch as soon as possible.  The branch may have died of cold injury. I do not see any  amber-colored gummosis.  Look for insect wounds and cankers.